xdp: T2666: switch to example code provided by xdp-tutorial

32 files changed, 7260 insertions, 0 deletions

diff --git a/src/xdp/.gitignore b/src/xdp/.gitignore
new file mode 100644
index 000000000..2c931cf47
--- /dev/null
+++ b/src/xdp/.gitignore
@@ -0,0 +1,5 @@
+*.o
+*.ll
+xdp_loader
+xdp_prog_user
+xdp_stats
diff --git a/src/xdp/Makefile b/src/xdp/Makefile
new file mode 100644
index 000000000..0b5a6eaa0
--- /dev/null
+++ b/src/xdp/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+
+XDP_TARGETS  := xdp_prog_kern
+USER_TARGETS := xdp_prog_user
+
+COMMON_DIR = common
+
+COPY_LOADER := xdp_loader
+COPY_STATS  := xdp_stats
+EXTRA_DEPS := $(COMMON_DIR)/parsing_helpers.h
+
+include $(COMMON_DIR)/common.mk
diff --git a/src/xdp/common/Makefile b/src/xdp/common/Makefile
new file mode 100644
index 000000000..2502027e9
--- /dev/null
+++ b/src/xdp/common/Makefile
@@ -0,0 +1,23 @@
+# SPDX-License-Identifier: (GPL-2.0)
+CC := gcc
+
+all: common_params.o common_user_bpf_xdp.o common_libbpf.o
+
+CFLAGS := -g -Wall
+
+CFLAGS += -I../include/
+# TODO: Do we need to make libbpf from this make file too?
+
+common_params.o: common_params.c common_params.h
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+common_user_bpf_xdp.o: common_user_bpf_xdp.c common_user_bpf_xdp.h
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+common_libbpf.o: common_libbpf.c common_libbpf.h
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+.PHONY: clean
+
+clean:
+	rm -f *.o
diff --git a/src/xdp/common/README.org b/src/xdp/common/README.org
new file mode 100644
index 000000000..561fdbced
--- /dev/null
+++ b/src/xdp/common/README.org
@@ -0,0 +1,8 @@
+# -*- fill-column: 76; -*-
+#+TITLE: Common files
+#+OPTIONS: ^:nil
+
+This directory contains code that is common between the different
+assignments. This reduce code duplication in each tutorial assignment, and
+allow us to hideaway code that is irrelevant or have been seen/introduced in
+earlier assignments.
diff --git a/src/xdp/common/common.mk b/src/xdp/common/common.mk
new file mode 100644
index 000000000..89aac68ef
--- /dev/null
+++ b/src/xdp/common/common.mk
@@ -0,0 +1,103 @@
+# Common Makefile parts for BPF-building with libbpf
+# --------------------------------------------------
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+#
+# This file should be included from your Makefile like:
+#  COMMON_DIR = ../common/
+#  include $(COMMON_DIR)/common.mk
+#
+# It is expected that you define the variables:
+#  XDP_TARGETS and USER_TARGETS
+# as a space-separated list
+#
+LLC ?= llc
+CLANG ?= clang
+CC ?= gcc
+
+XDP_C = ${XDP_TARGETS:=.c}
+XDP_OBJ = ${XDP_C:.c=.o}
+USER_C := ${USER_TARGETS:=.c}
+USER_OBJ := ${USER_C:.c=.o}
+
+# Expect this is defined by including Makefile, but define if not
+COMMON_DIR ?= ../common/
+
+COPY_LOADER ?=
+LOADER_DIR ?= $(COMMON_DIR)/../utils
+
+# Extend if including Makefile already added some
+COMMON_OBJS += $(COMMON_DIR)/common_params.o $(COMMON_DIR)/common_user_bpf_xdp.o
+
+# Create expansions for dependencies
+COMMON_H := ${COMMON_OBJS:.o=.h}
+
+EXTRA_DEPS +=
+
+# BPF-prog kern and userspace shares struct via header file:
+KERN_USER_H ?= $(wildcard common_kern_user.h)
+
+CFLAGS ?= -g -I../include/
+BPF_CFLAGS ?= -I../include/
+
+LIBS = -l:libbpf.a -lelf -lz $(USER_LIBS)
+
+all: llvm-check $(USER_TARGETS) $(XDP_OBJ) $(COPY_LOADER) $(COPY_STATS)
+
+.PHONY: clean $(CLANG) $(LLC)
+
+clean:
+	$(MAKE) -C $(COMMON_DIR) clean
+	rm -f $(USER_TARGETS) $(XDP_OBJ) $(USER_OBJ) $(COPY_LOADER) $(COPY_STATS)
+	rm -f *.ll
+	rm -f *~
+
+ifdef COPY_LOADER
+$(COPY_LOADER): $(LOADER_DIR)/${COPY_LOADER:=.c} $(COMMON_H)
+	make -C $(LOADER_DIR) $(COPY_LOADER)
+	cp $(LOADER_DIR)/$(COPY_LOADER) $(COPY_LOADER)
+endif
+
+ifdef COPY_STATS
+$(COPY_STATS): $(LOADER_DIR)/${COPY_STATS:=.c} $(COMMON_H)
+	make -C $(LOADER_DIR) $(COPY_STATS)
+	cp $(LOADER_DIR)/$(COPY_STATS) $(COPY_STATS)
+# Needing xdp_stats imply depending on header files:
+EXTRA_DEPS += $(COMMON_DIR)/xdp_stats_kern.h $(COMMON_DIR)/xdp_stats_kern_user.h
+endif
+
+# For build dependency on this file, if it gets updated
+COMMON_MK = $(COMMON_DIR)/common.mk
+
+llvm-check: $(CLANG) $(LLC)
+	@for TOOL in $^ ; do \
+		if [ ! $$(command -v $${TOOL} 2>/dev/null) ]; then \
+			echo "*** ERROR: Cannot find tool $${TOOL}" ;\
+			exit 1; \
+		else true; fi; \
+	done
+
+# Create dependency: detect if C-file change and touch H-file, to trigger
+# target $(COMMON_OBJS)
+$(COMMON_H): %.h: %.c
+	touch $@
+
+# Detect if any of common obj changed and create dependency on .h-files
+$(COMMON_OBJS): %.o: %.h
+	make -C $(COMMON_DIR)
+
+$(USER_TARGETS): %: %.c  Makefile $(COMMON_MK) $(COMMON_OBJS) $(KERN_USER_H) $(EXTRA_DEPS)
+	$(CC) -Wall $(CFLAGS) $(LDFLAGS) -o $@ $(COMMON_OBJS) \
+	 $< $(LIBS)
+
+$(XDP_OBJ): %.o: %.c  Makefile $(COMMON_MK) $(KERN_USER_H) $(EXTRA_DEPS)
+	$(CLANG) -S \
+	    -target bpf \
+	    -D __BPF_TRACING__ \
+	    $(BPF_CFLAGS) \
+	    -Wall \
+	    -Wno-unused-value \
+	    -Wno-pointer-sign \
+	    -Wno-compare-distinct-pointer-types \
+	    -Werror \
+	    -O2 -emit-llvm -c -g -o ${@:.o=.ll} $<
+	$(LLC) -march=bpf -filetype=obj -o $@ ${@:.o=.ll}
diff --git a/src/xdp/common/common_defines.h b/src/xdp/common/common_defines.h
new file mode 100644
index 000000000..2986d2d67
--- /dev/null
+++ b/src/xdp/common/common_defines.h
@@ -0,0 +1,38 @@
+#ifndef __COMMON_DEFINES_H
+#define __COMMON_DEFINES_H
+
+#include <net/if.h>
+#include <linux/types.h>
+#include <stdbool.h>
+
+struct config {
+	__u32 xdp_flags;
+	int ifindex;
+	char *ifname;
+	char ifname_buf[IF_NAMESIZE];
+	int redirect_ifindex;
+	char *redirect_ifname;
+	char redirect_ifname_buf[IF_NAMESIZE];
+	bool do_unload;
+	bool reuse_maps;
+	char pin_dir[512];
+	char filename[512];
+	char progsec[32];
+	char src_mac[18];
+	char dest_mac[18];
+	__u16 xsk_bind_flags;
+	int xsk_if_queue;
+	bool xsk_poll_mode;
+};
+
+/* Defined in common_params.o */
+extern int verbose;
+
+/* Exit return codes */
+#define EXIT_OK 		 0 /* == EXIT_SUCCESS (stdlib.h) man exit(3) */
+#define EXIT_FAIL		 1 /* == EXIT_FAILURE (stdlib.h) man exit(3) */
+#define EXIT_FAIL_OPTION	 2
+#define EXIT_FAIL_XDP		30
+#define EXIT_FAIL_BPF		40
+
+#endif /* __COMMON_DEFINES_H */
diff --git a/src/xdp/common/common_libbpf.c b/src/xdp/common/common_libbpf.c
new file mode 100644
index 000000000..5788ecd9e
--- /dev/null
+++ b/src/xdp/common/common_libbpf.c
@@ -0,0 +1,162 @@
+/* Common function that with time should be moved to libbpf */
+
+#include <errno.h>
+#include <string.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include "common_libbpf.h"
+
+/* From: include/linux/err.h */
+#define MAX_ERRNO       4095
+#define IS_ERR_VALUE(x) ((x) >= (unsigned long)-MAX_ERRNO)
+static inline bool IS_ERR_OR_NULL(const void *ptr)
+{
+        return (!ptr) || IS_ERR_VALUE((unsigned long)ptr);
+}
+
+#define pr_warning printf
+
+/* As close as possible to libbpf bpf_prog_load_xattr(), with the
+ * difference of handling pinned maps.
+ */
+int bpf_prog_load_xattr_maps(const struct bpf_prog_load_attr_maps *attr,
+			     struct bpf_object **pobj, int *prog_fd)
+{
+	struct bpf_object_open_attr open_attr = {
+		.file		= attr->file,
+		.prog_type	= attr->prog_type,
+	};
+	struct bpf_program *prog, *first_prog = NULL;
+	enum bpf_attach_type expected_attach_type;
+	enum bpf_prog_type prog_type;
+	struct bpf_object *obj;
+	struct bpf_map *map;
+	int err;
+	int i;
+
+	if (!attr)
+		return -EINVAL;
+	if (!attr->file)
+		return -EINVAL;
+
+
+	obj = bpf_object__open_xattr(&open_attr);
+	if (IS_ERR_OR_NULL(obj))
+		return -ENOENT;
+
+	bpf_object__for_each_program(prog, obj) {
+		/*
+		 * If type is not specified, try to guess it based on
+		 * section name.
+		 */
+		prog_type = attr->prog_type;
+		// Was: prog->prog_ifindex = attr->ifindex;
+		bpf_program__set_ifindex(prog, attr->ifindex);
+
+		expected_attach_type = attr->expected_attach_type;
+#if 0 /* Use internal libbpf variables */
+		if (prog_type == BPF_PROG_TYPE_UNSPEC) {
+			err = bpf_program__identify_section(prog, &prog_type,
+							    &expected_attach_type);
+			if (err < 0) {
+				bpf_object__close(obj);
+				return -EINVAL;
+			}
+		}
+#endif
+
+		bpf_program__set_type(prog, prog_type);
+		bpf_program__set_expected_attach_type(prog,
+						      expected_attach_type);
+
+		if (!first_prog)
+			first_prog = prog;
+	}
+
+	/* Reset attr->pinned_maps.map_fd to identify successful file load */
+	for (i = 0; i < attr->nr_pinned_maps; i++)
+		attr->pinned_maps[i].map_fd = -1;
+
+	bpf_map__for_each(map, obj) {
+		const char* mapname = bpf_map__name(map);
+
+		if (!bpf_map__is_offload_neutral(map))
+			bpf_map__set_ifindex(map, attr->ifindex);
+                        /* Was: map->map_ifindex = attr->ifindex; */
+
+		for (i = 0; i < attr->nr_pinned_maps; i++) {
+			struct bpf_pinned_map *pin_map = &attr->pinned_maps[i];
+			int fd;
+
+			if (strcmp(mapname, pin_map->name) != 0)
+				continue;
+
+			/* Matched, try opening pinned file */
+			fd = bpf_obj_get(pin_map->filename);
+			if (fd > 0) {
+				/* Use FD from pinned map as replacement */
+				bpf_map__reuse_fd(map, fd);
+				/* TODO: Might want to set internal map "name"
+				 * if opened pinned map didn't, to allow
+				 * bpf_object__find_map_fd_by_name() to work.
+				 */
+				pin_map->map_fd = fd;
+				continue;
+			}
+			/* Could not open pinned filename map, then this prog
+			 * should then pin the map, BUT this can only happen
+			 * after bpf_object__load().
+			 */
+		}
+	}
+
+	if (!first_prog) {
+		pr_warning("object file doesn't contain bpf program\n");
+		bpf_object__close(obj);
+		return -ENOENT;
+	}
+
+	err = bpf_object__load(obj);
+	if (err) {
+		bpf_object__close(obj);
+		return -EINVAL;
+	}
+
+	/* Pin the maps that were not loaded via pinned filename */
+	bpf_map__for_each(map, obj) {
+		const char* mapname = bpf_map__name(map);
+
+		for (i = 0; i < attr->nr_pinned_maps; i++) {
+			struct bpf_pinned_map *pin_map = &attr->pinned_maps[i];
+			int err;
+
+			if (strcmp(mapname, pin_map->name) != 0)
+				continue;
+
+			/* Matched, check if map is already loaded */
+			if (pin_map->map_fd != -1)
+				continue;
+
+			/* Needs to be pinned */
+			err = bpf_map__pin(map, pin_map->filename);
+			if (err)
+				continue;
+			pin_map->map_fd = bpf_map__fd(map);
+		}
+	}
+
+	/* Help user if requested map name that doesn't exist */
+	for (i = 0; i < attr->nr_pinned_maps; i++) {
+		struct bpf_pinned_map *pin_map = &attr->pinned_maps[i];
+
+		if (pin_map->map_fd < 0)
+			pr_warning("%s() requested mapname:%s not seen\n",
+				   __func__, pin_map->name);
+	}
+
+	*pobj = obj;
+	*prog_fd = bpf_program__fd(first_prog);
+	return 0;
+}
diff --git a/src/xdp/common/common_libbpf.h b/src/xdp/common/common_libbpf.h
new file mode 100644
index 000000000..4754bd8ca
--- /dev/null
+++ b/src/xdp/common/common_libbpf.h
@@ -0,0 +1,24 @@
+/* Common function that with time should be moved to libbpf */
+#ifndef __COMMON_LIBBPF_H
+#define __COMMON_LIBBPF_H
+
+struct bpf_pinned_map {
+	const char *name;
+	const char *filename;
+	int map_fd;
+};
+
+/*     bpf_prog_load_attr extended */
+struct bpf_prog_load_attr_maps {
+	const char *file;
+	enum bpf_prog_type prog_type;
+	enum bpf_attach_type expected_attach_type;
+	int ifindex;
+	int nr_pinned_maps;
+	struct bpf_pinned_map *pinned_maps;
+};
+
+int bpf_prog_load_xattr_maps(const struct bpf_prog_load_attr_maps *attr,
+			     struct bpf_object **pobj, int *prog_fd);
+
+#endif /* __COMMON_LIBBPF_H */
diff --git a/src/xdp/common/common_params.c b/src/xdp/common/common_params.c
new file mode 100644
index 000000000..642d56d92
--- /dev/null
+++ b/src/xdp/common/common_params.c
@@ -0,0 +1,197 @@
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+#include <getopt.h>
+#include <errno.h>
+
+#include <net/if.h>
+#include <linux/if_link.h> /* XDP_FLAGS_* depend on kernel-headers installed */
+#include <linux/if_xdp.h>
+
+#include "common_params.h"
+
+int verbose = 1;
+
+#define BUFSIZE 30
+
+void _print_options(const struct option_wrapper *long_options, bool required)
+{
+	int i, pos;
+	char buf[BUFSIZE];
+
+	for (i = 0; long_options[i].option.name != 0; i++) {
+		if (long_options[i].required != required)
+			continue;
+
+		if (long_options[i].option.val > 64) /* ord('A') = 65 */
+			printf(" -%c,", long_options[i].option.val);
+		else
+			printf("    ");
+		pos = snprintf(buf, BUFSIZE, " --%s", long_options[i].option.name);
+		if (long_options[i].metavar)
+			snprintf(&buf[pos], BUFSIZE-pos, " %s", long_options[i].metavar);
+		printf("%-22s", buf);
+		printf("  %s", long_options[i].help);
+		printf("\n");
+	}
+}
+
+void usage(const char *prog_name, const char *doc,
+           const struct option_wrapper *long_options, bool full)
+{
+	printf("Usage: %s [options]\n", prog_name);
+
+	if (!full) {
+		printf("Use --help (or -h) to see full option list.\n");
+		return;
+	}
+
+	printf("\nDOCUMENTATION:\n %s\n", doc);
+	printf("Required options:\n");
+	_print_options(long_options, true);
+	printf("\n");
+	printf("Other options:\n");
+	_print_options(long_options, false);
+	printf("\n");
+}
+
+int option_wrappers_to_options(const struct option_wrapper *wrapper,
+				struct option **options)
+{
+	int i, num;
+	struct option *new_options;
+	for (i = 0; wrapper[i].option.name != 0; i++) {}
+	num = i;
+
+	new_options = malloc(sizeof(struct option) * num);
+	if (!new_options)
+		return -1;
+	for (i = 0; i < num; i++) {
+		memcpy(&new_options[i], &wrapper[i], sizeof(struct option));
+	}
+
+	*options = new_options;
+	return 0;
+}
+
+void parse_cmdline_args(int argc, char **argv,
+			const struct option_wrapper *options_wrapper,
+                        struct config *cfg, const char *doc)
+{
+	struct option *long_options;
+	bool full_help = false;
+	int longindex = 0;
+	char *dest;
+	int opt;
+
+	if (option_wrappers_to_options(options_wrapper, &long_options)) {
+		fprintf(stderr, "Unable to malloc()\n");
+		exit(EXIT_FAIL_OPTION);
+	}
+
+	/* Parse commands line args */
+	while ((opt = getopt_long(argc, argv, "hd:r:L:R:ASNFUMQ:czpq",
+				  long_options, &longindex)) != -1) {
+		switch (opt) {
+		case 'd':
+			if (strlen(optarg) >= IF_NAMESIZE) {
+				fprintf(stderr, "ERR: --dev name too long\n");
+				goto error;
+			}
+			cfg->ifname = (char *)&cfg->ifname_buf;
+			strncpy(cfg->ifname, optarg, IF_NAMESIZE);
+			cfg->ifindex = if_nametoindex(cfg->ifname);
+			if (cfg->ifindex == 0) {
+				fprintf(stderr,
+					"ERR: --dev name unknown err(%d):%s\n",
+					errno, strerror(errno));
+				goto error;
+			}
+			break;
+		case 'r':
+			if (strlen(optarg) >= IF_NAMESIZE) {
+				fprintf(stderr, "ERR: --redirect-dev name too long\n");
+				goto error;
+			}
+			cfg->redirect_ifname = (char *)&cfg->redirect_ifname_buf;
+			strncpy(cfg->redirect_ifname, optarg, IF_NAMESIZE);
+			cfg->redirect_ifindex = if_nametoindex(cfg->redirect_ifname);
+			if (cfg->redirect_ifindex == 0) {
+				fprintf(stderr,
+						"ERR: --redirect-dev name unknown err(%d):%s\n",
+						errno, strerror(errno));
+				goto error;
+			}
+			break;
+		case 'A':
+			cfg->xdp_flags &= ~XDP_FLAGS_MODES;    /* Clear flags */
+			break;
+		case 'S':
+			cfg->xdp_flags &= ~XDP_FLAGS_MODES;    /* Clear flags */
+			cfg->xdp_flags |= XDP_FLAGS_SKB_MODE;  /* Set   flag */
+			cfg->xsk_bind_flags &= XDP_ZEROCOPY;
+			cfg->xsk_bind_flags |= XDP_COPY;
+			break;
+		case 'N':
+			cfg->xdp_flags &= ~XDP_FLAGS_MODES;    /* Clear flags */
+			cfg->xdp_flags |= XDP_FLAGS_DRV_MODE;  /* Set   flag */
+			break;
+		case 3: /* --offload-mode */
+			cfg->xdp_flags &= ~XDP_FLAGS_MODES;    /* Clear flags */
+			cfg->xdp_flags |= XDP_FLAGS_HW_MODE;   /* Set   flag */
+			break;
+		case 'F':
+			cfg->xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		case 'M':
+			cfg->reuse_maps = true;
+			break;
+		case 'U':
+			cfg->do_unload = true;
+			break;
+		case 'p':
+			cfg->xsk_poll_mode = true;
+			break;
+		case 'q':
+			verbose = false;
+			break;
+		case 'Q':
+			cfg->xsk_if_queue = atoi(optarg);
+			break;
+		case 1: /* --filename */
+			dest  = (char *)&cfg->filename;
+			strncpy(dest, optarg, sizeof(cfg->filename));
+			break;
+		case 2: /* --progsec */
+			dest  = (char *)&cfg->progsec;
+			strncpy(dest, optarg, sizeof(cfg->progsec));
+			break;
+		case 'L': /* --src-mac */
+			dest  = (char *)&cfg->src_mac;
+			strncpy(dest, optarg, sizeof(cfg->src_mac));
+			break;
+		case 'R': /* --dest-mac */
+			dest  = (char *)&cfg->dest_mac;
+			strncpy(dest, optarg, sizeof(cfg->dest_mac));
+		case 'c':
+			cfg->xsk_bind_flags &= XDP_ZEROCOPY;
+			cfg->xsk_bind_flags |= XDP_COPY;
+			break;
+		case 'z':
+			cfg->xsk_bind_flags &= XDP_COPY;
+			cfg->xsk_bind_flags |= XDP_ZEROCOPY;
+			break;
+		case 'h':
+			full_help = true;
+			/* fall-through */
+		error:
+		default:
+			usage(argv[0], doc, options_wrapper, full_help);
+			free(long_options);
+			exit(EXIT_FAIL_OPTION);
+		}
+	}
+	free(long_options);
+}
diff --git a/src/xdp/common/common_params.h b/src/xdp/common/common_params.h
new file mode 100644
index 000000000..6f64c82e3
--- /dev/null
+++ b/src/xdp/common/common_params.h
@@ -0,0 +1,22 @@
+/* This common_user.h is used by userspace programs */
+#ifndef __COMMON_PARAMS_H
+#define __COMMON_PARAMS_H
+
+#include <getopt.h>
+#include "common_defines.h"
+
+struct option_wrapper {
+  struct option option;
+  char *help;
+  char *metavar;
+  bool required;
+};
+
+void usage(const char *prog_name, const char *doc,
+           const struct option_wrapper *long_options, bool full);
+
+void parse_cmdline_args(int argc, char **argv,
+			const struct option_wrapper *long_options,
+                        struct config *cfg, const char *doc);
+
+#endif /* __COMMON_PARAMS_H */
diff --git a/src/xdp/common/common_user_bpf_xdp.c b/src/xdp/common/common_user_bpf_xdp.c
new file mode 100644
index 000000000..e7ef77174
--- /dev/null
+++ b/src/xdp/common/common_user_bpf_xdp.c
@@ -0,0 +1,380 @@
+#include <bpf/libbpf.h> /* bpf_get_link_xdp_id + bpf_set_link_xdp_id */
+#include <string.h>     /* strerror */
+#include <net/if.h>     /* IF_NAMESIZE */
+#include <stdlib.h>     /* exit(3) */
+#include <errno.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include <linux/if_link.h> /* Need XDP flags */
+#include <linux/err.h>
+
+#include "common_defines.h"
+
+#ifndef PATH_MAX
+#define PATH_MAX	4096
+#endif
+
+int xdp_link_attach(int ifindex, __u32 xdp_flags, int prog_fd)
+{
+	int err;
+
+	/* libbpf provide the XDP net_device link-level hook attach helper */
+	err = bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags);
+	if (err == -EEXIST && !(xdp_flags & XDP_FLAGS_UPDATE_IF_NOEXIST)) {
+		/* Force mode didn't work, probably because a program of the
+		 * opposite type is loaded. Let's unload that and try loading
+		 * again.
+		 */
+
+		__u32 old_flags = xdp_flags;
+
+		xdp_flags &= ~XDP_FLAGS_MODES;
+		xdp_flags |= (old_flags & XDP_FLAGS_SKB_MODE) ? XDP_FLAGS_DRV_MODE : XDP_FLAGS_SKB_MODE;
+		err = bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
+		if (!err)
+			err = bpf_set_link_xdp_fd(ifindex, prog_fd, old_flags);
+	}
+	if (err < 0) {
+		fprintf(stderr, "ERR: "
+			"ifindex(%d) link set xdp fd failed (%d): %s\n",
+			ifindex, -err, strerror(-err));
+
+		switch (-err) {
+		case EBUSY:
+		case EEXIST:
+			fprintf(stderr, "Hint: XDP already loaded on device"
+				" use --force to swap/replace\n");
+			break;
+		case EOPNOTSUPP:
+			fprintf(stderr, "Hint: Native-XDP not supported"
+				" use --skb-mode or --auto-mode\n");
+			break;
+		default:
+			break;
+		}
+		return EXIT_FAIL_XDP;
+	}
+
+	return EXIT_OK;
+}
+
+int xdp_link_detach(int ifindex, __u32 xdp_flags, __u32 expected_prog_id)
+{
+	__u32 curr_prog_id;
+	int err;
+
+	err = bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags);
+	if (err) {
+		fprintf(stderr, "ERR: get link xdp id failed (err=%d): %s\n",
+			-err, strerror(-err));
+		return EXIT_FAIL_XDP;
+	}
+
+	if (!curr_prog_id) {
+		if (verbose)
+			printf("INFO: %s() no curr XDP prog on ifindex:%d\n",
+			       __func__, ifindex);
+		return EXIT_OK;
+	}
+
+	if (expected_prog_id && curr_prog_id != expected_prog_id) {
+		fprintf(stderr, "ERR: %s() "
+			"expected prog ID(%d) no match(%d), not removing\n",
+			__func__, expected_prog_id, curr_prog_id);
+		return EXIT_FAIL;
+	}
+
+	if ((err = bpf_set_link_xdp_fd(ifindex, -1, xdp_flags)) < 0) {
+		fprintf(stderr, "ERR: %s() link set xdp failed (err=%d): %s\n",
+			__func__, err, strerror(-err));
+		return EXIT_FAIL_XDP;
+	}
+
+	if (verbose)
+		printf("INFO: %s() removed XDP prog ID:%d on ifindex:%d\n",
+		       __func__, curr_prog_id, ifindex);
+
+	return EXIT_OK;
+}
+
+struct bpf_object *load_bpf_object_file(const char *filename, int ifindex)
+{
+	int first_prog_fd = -1;
+	struct bpf_object *obj;
+	int err;
+
+	/* This struct allow us to set ifindex, this features is used for
+	 * hardware offloading XDP programs (note this sets libbpf
+	 * bpf_program->prog_ifindex and foreach bpf_map->map_ifindex).
+	 */
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type = BPF_PROG_TYPE_XDP,
+		.ifindex   = ifindex,
+	};
+	prog_load_attr.file = filename;
+
+	/* Use libbpf for extracting BPF byte-code from BPF-ELF object, and
+	 * loading this into the kernel via bpf-syscall
+	 */
+	err = bpf_prog_load_xattr(&prog_load_attr, &obj, &first_prog_fd);
+	if (err) {
+		fprintf(stderr, "ERR: loading BPF-OBJ file(%s) (%d): %s\n",
+			filename, err, strerror(-err));
+		return NULL;
+	}
+
+	/* Notice how a pointer to a libbpf bpf_object is returned */
+	return obj;
+}
+
+static struct bpf_object *open_bpf_object(const char *file, int ifindex)
+{
+	int err;
+	struct bpf_object *obj;
+	struct bpf_map *map;
+	struct bpf_program *prog, *first_prog = NULL;
+
+	struct bpf_object_open_attr open_attr = {
+		.file = file,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	};
+
+	obj = bpf_object__open_xattr(&open_attr);
+	if (IS_ERR_OR_NULL(obj)) {
+		err = -PTR_ERR(obj);
+		fprintf(stderr, "ERR: opening BPF-OBJ file(%s) (%d): %s\n",
+			file, err, strerror(-err));
+		return NULL;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		bpf_program__set_type(prog, BPF_PROG_TYPE_XDP);
+		bpf_program__set_ifindex(prog, ifindex);
+		if (!first_prog)
+			first_prog = prog;
+	}
+
+	bpf_object__for_each_map(map, obj) {
+		if (!bpf_map__is_offload_neutral(map))
+			bpf_map__set_ifindex(map, ifindex);
+	}
+
+	if (!first_prog) {
+		fprintf(stderr, "ERR: file %s contains no programs\n", file);
+		return NULL;
+	}
+
+	return obj;
+}
+
+static int reuse_maps(struct bpf_object *obj, const char *path)
+{
+	struct bpf_map *map;
+
+	if (!obj)
+		return -ENOENT;
+
+	if (!path)
+		return -EINVAL;
+
+	bpf_object__for_each_map(map, obj) {
+		int len, err;
+		int pinned_map_fd;
+		char buf[PATH_MAX];
+
+		len = snprintf(buf, PATH_MAX, "%s/%s", path, bpf_map__name(map));
+		if (len < 0) {
+			return -EINVAL;
+		} else if (len >= PATH_MAX) {
+			return -ENAMETOOLONG;
+		}
+
+		pinned_map_fd = bpf_obj_get(buf);
+		if (pinned_map_fd < 0)
+			return pinned_map_fd;
+
+		err = bpf_map__reuse_fd(map, pinned_map_fd);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+struct bpf_object *load_bpf_object_file_reuse_maps(const char *file,
+						   int ifindex,
+						   const char *pin_dir)
+{
+	int err;
+	struct bpf_object *obj;
+
+	obj = open_bpf_object(file, ifindex);
+	if (!obj) {
+		fprintf(stderr, "ERR: failed to open object %s\n", file);
+		return NULL;
+	}
+
+	err = reuse_maps(obj, pin_dir);
+	if (err) {
+		fprintf(stderr, "ERR: failed to reuse maps for object %s, pin_dir=%s\n",
+				file, pin_dir);
+		return NULL;
+	}
+
+	err = bpf_object__load(obj);
+	if (err) {
+		fprintf(stderr, "ERR: loading BPF-OBJ file(%s) (%d): %s\n",
+			file, err, strerror(-err));
+		return NULL;
+	}
+
+	return obj;
+}
+
+struct bpf_object *load_bpf_and_xdp_attach(struct config *cfg)
+{
+	struct bpf_program *bpf_prog;
+	struct bpf_object *bpf_obj;
+	int offload_ifindex = 0;
+	int prog_fd = -1;
+	int err;
+
+	/* If flags indicate hardware offload, supply ifindex */
+	if (cfg->xdp_flags & XDP_FLAGS_HW_MODE)
+		offload_ifindex = cfg->ifindex;
+
+	/* Load the BPF-ELF object file and get back libbpf bpf_object */
+	if (cfg->reuse_maps)
+		bpf_obj = load_bpf_object_file_reuse_maps(cfg->filename,
+							  offload_ifindex,
+							  cfg->pin_dir);
+	else
+		bpf_obj = load_bpf_object_file(cfg->filename, offload_ifindex);
+	if (!bpf_obj) {
+		fprintf(stderr, "ERR: loading file: %s\n", cfg->filename);
+		exit(EXIT_FAIL_BPF);
+	}
+	/* At this point: All XDP/BPF programs from the cfg->filename have been
+	 * loaded into the kernel, and evaluated by the verifier. Only one of
+	 * these gets attached to XDP hook, the others will get freed once this
+	 * process exit.
+	 */
+
+	if (cfg->progsec[0])
+		/* Find a matching BPF prog section name */
+		bpf_prog = bpf_object__find_program_by_title(bpf_obj, cfg->progsec);
+	else
+		/* Find the first program */
+		bpf_prog = bpf_program__next(NULL, bpf_obj);
+
+	if (!bpf_prog) {
+		fprintf(stderr, "ERR: couldn't find a program in ELF section '%s'\n", cfg->progsec);
+		exit(EXIT_FAIL_BPF);
+	}
+
+	strncpy(cfg->progsec, bpf_program__title(bpf_prog, false), sizeof(cfg->progsec));
+
+	prog_fd = bpf_program__fd(bpf_prog);
+	if (prog_fd <= 0) {
+		fprintf(stderr, "ERR: bpf_program__fd failed\n");
+		exit(EXIT_FAIL_BPF);
+	}
+
+	/* At this point: BPF-progs are (only) loaded by the kernel, and prog_fd
+	 * is our select file-descriptor handle. Next step is attaching this FD
+	 * to a kernel hook point, in this case XDP net_device link-level hook.
+	 */
+	err = xdp_link_attach(cfg->ifindex, cfg->xdp_flags, prog_fd);
+	if (err)
+		exit(err);
+
+	return bpf_obj;
+}
+
+#define XDP_UNKNOWN	XDP_REDIRECT + 1
+#ifndef XDP_ACTION_MAX
+#define XDP_ACTION_MAX (XDP_UNKNOWN + 1)
+#endif
+
+static const char *xdp_action_names[XDP_ACTION_MAX] = {
+	[XDP_ABORTED]   = "XDP_ABORTED",
+	[XDP_DROP]      = "XDP_DROP",
+	[XDP_PASS]      = "XDP_PASS",
+	[XDP_TX]        = "XDP_TX",
+	[XDP_REDIRECT]  = "XDP_REDIRECT",
+	[XDP_UNKNOWN]	= "XDP_UNKNOWN",
+};
+
+const char *action2str(__u32 action)
+{
+        if (action < XDP_ACTION_MAX)
+                return xdp_action_names[action];
+        return NULL;
+}
+
+int check_map_fd_info(const struct bpf_map_info *info,
+		      const struct bpf_map_info *exp)
+{
+	if (exp->key_size && exp->key_size != info->key_size) {
+		fprintf(stderr, "ERR: %s() "
+			"Map key size(%d) mismatch expected size(%d)\n",
+			__func__, info->key_size, exp->key_size);
+		return EXIT_FAIL;
+	}
+	if (exp->value_size && exp->value_size != info->value_size) {
+		fprintf(stderr, "ERR: %s() "
+			"Map value size(%d) mismatch expected size(%d)\n",
+			__func__, info->value_size, exp->value_size);
+		return EXIT_FAIL;
+	}
+	if (exp->max_entries && exp->max_entries != info->max_entries) {
+		fprintf(stderr, "ERR: %s() "
+			"Map max_entries(%d) mismatch expected size(%d)\n",
+			__func__, info->max_entries, exp->max_entries);
+		return EXIT_FAIL;
+	}
+	if (exp->type && exp->type  != info->type) {
+		fprintf(stderr, "ERR: %s() "
+			"Map type(%d) mismatch expected type(%d)\n",
+			__func__, info->type, exp->type);
+		return EXIT_FAIL;
+	}
+
+	return 0;
+}
+
+int open_bpf_map_file(const char *pin_dir,
+		      const char *mapname,
+		      struct bpf_map_info *info)
+{
+	char filename[PATH_MAX];
+	int err, len, fd;
+	__u32 info_len = sizeof(*info);
+
+	len = snprintf(filename, PATH_MAX, "%s/%s", pin_dir, mapname);
+	if (len < 0) {
+		fprintf(stderr, "ERR: constructing full mapname path\n");
+		return -1;
+	}
+
+	fd = bpf_obj_get(filename);
+	if (fd < 0) {
+		fprintf(stderr,
+			"WARN: Failed to open bpf map file:%s err(%d):%s\n",
+			filename, errno, strerror(errno));
+		return fd;
+	}
+
+	if (info) {
+		err = bpf_obj_get_info_by_fd(fd, info, &info_len);
+		if (err) {
+			fprintf(stderr, "ERR: %s() can't get info - %s\n",
+				__func__,  strerror(errno));
+			return EXIT_FAIL_BPF;
+		}
+	}
+
+	return fd;
+}
diff --git a/src/xdp/common/common_user_bpf_xdp.h b/src/xdp/common/common_user_bpf_xdp.h
new file mode 100644
index 000000000..4f8aa51d4
--- /dev/null
+++ b/src/xdp/common/common_user_bpf_xdp.h
@@ -0,0 +1,20 @@
+/* Common BPF/XDP functions used by userspace side programs */
+#ifndef __COMMON_USER_BPF_XDP_H
+#define __COMMON_USER_BPF_XDP_H
+
+int xdp_link_attach(int ifindex, __u32 xdp_flags, int prog_fd);
+int xdp_link_detach(int ifindex, __u32 xdp_flags, __u32 expected_prog_id);
+
+struct bpf_object *load_bpf_object_file(const char *filename, int ifindex);
+struct bpf_object *load_bpf_and_xdp_attach(struct config *cfg);
+
+const char *action2str(__u32 action);
+
+int check_map_fd_info(const struct bpf_map_info *info,
+                      const struct bpf_map_info *exp);
+
+int open_bpf_map_file(const char *pin_dir,
+		      const char *mapname,
+		      struct bpf_map_info *info);
+
+#endif /* __COMMON_USER_BPF_XDP_H */
diff --git a/src/xdp/common/parsing_helpers.h b/src/xdp/common/parsing_helpers.h
new file mode 100644
index 000000000..c0837e88f
--- /dev/null
+++ b/src/xdp/common/parsing_helpers.h
@@ -0,0 +1,244 @@
+/* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-clause) */
+/*
+ * This file contains parsing functions that are used in the packetXX XDP
+ * programs. The functions are marked as __always_inline, and fully defined in
+ * this header file to be included in the BPF program.
+ *
+ * Each helper parses a packet header, including doing bounds checking, and
+ * returns the type of its contents if successful, and -1 otherwise.
+ *
+ * For Ethernet and IP headers, the content type is the type of the payload
+ * (h_proto for Ethernet, nexthdr for IPv6), for ICMP it is the ICMP type field.
+ * All return values are in host byte order.
+ *
+ * The versions of the functions included here are slightly expanded versions of
+ * the functions in the packet01 lesson. For instance, the Ethernet header
+ * parsing has support for parsing VLAN tags.
+ */
+
+#ifndef __PARSING_HELPERS_H
+#define __PARSING_HELPERS_H
+
+#include <stddef.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/icmp.h>
+#include <linux/icmpv6.h>
+#include <linux/udp.h>
+#include <linux/tcp.h>
+
+/* Header cursor to keep track of current parsing position */
+struct hdr_cursor {
+	void *pos;
+};
+
+/*
+ *	struct vlan_hdr - vlan header
+ *	@h_vlan_TCI: priority and VLAN ID
+ *	@h_vlan_encapsulated_proto: packet type ID or len
+ */
+struct vlan_hdr {
+	__be16	h_vlan_TCI;
+	__be16	h_vlan_encapsulated_proto;
+};
+
+/*
+ * Struct icmphdr_common represents the common part of the icmphdr and icmp6hdr
+ * structures.
+ */
+struct icmphdr_common {
+	__u8		type;
+	__u8		code;
+	__sum16	cksum;
+};
+
+/* Allow users of header file to redefine VLAN max depth */
+#ifndef VLAN_MAX_DEPTH
+#define VLAN_MAX_DEPTH 4
+#endif
+
+static __always_inline int proto_is_vlan(__u16 h_proto)
+{
+	return !!(h_proto == bpf_htons(ETH_P_8021Q) ||
+		  h_proto == bpf_htons(ETH_P_8021AD));
+}
+
+/* Notice, parse_ethhdr() will skip VLAN tags, by advancing nh->pos and returns
+ * next header EtherType, BUT the ethhdr pointer supplied still points to the
+ * Ethernet header. Thus, caller can look at eth->h_proto to see if this was a
+ * VLAN tagged packet.
+ */
+static __always_inline int parse_ethhdr(struct hdr_cursor *nh, void *data_end,
+					struct ethhdr **ethhdr)
+{
+	struct ethhdr *eth = nh->pos;
+	int hdrsize = sizeof(*eth);
+	struct vlan_hdr *vlh;
+	__u16 h_proto;
+	int i;
+
+	/* Byte-count bounds check; check if current pointer + size of header
+	 * is after data_end.
+	 */
+	if (nh->pos + hdrsize > data_end)
+		return -1;
+
+	nh->pos += hdrsize;
+	*ethhdr = eth;
+	vlh = nh->pos;
+	h_proto = eth->h_proto;
+
+	/* Use loop unrolling to avoid the verifier restriction on loops;
+	 * support up to VLAN_MAX_DEPTH layers of VLAN encapsulation.
+	 */
+	#pragma unroll
+	for (i = 0; i < VLAN_MAX_DEPTH; i++) {
+		if (!proto_is_vlan(h_proto))
+			break;
+
+		if (vlh + 1 > data_end)
+			break;
+
+		h_proto = vlh->h_vlan_encapsulated_proto;
+		vlh++;
+	}
+
+	nh->pos = vlh;
+	return h_proto; /* network-byte-order */
+}
+
+static __always_inline int parse_ip6hdr(struct hdr_cursor *nh,
+					void *data_end,
+					struct ipv6hdr **ip6hdr)
+{
+	struct ipv6hdr *ip6h = nh->pos;
+
+	/* Pointer-arithmetic bounds check; pointer +1 points to after end of
+	 * thing being pointed to. We will be using this style in the remainder
+	 * of the tutorial.
+	 */
+	if (ip6h + 1 > data_end)
+		return -1;
+
+	nh->pos = ip6h + 1;
+	*ip6hdr = ip6h;
+
+	return ip6h->nexthdr;
+}
+
+static __always_inline int parse_iphdr(struct hdr_cursor *nh,
+				       void *data_end,
+				       struct iphdr **iphdr)
+{
+	struct iphdr *iph = nh->pos;
+	int hdrsize;
+
+	if (iph + 1 > data_end)
+		return -1;
+
+	hdrsize = iph->ihl * 4;
+
+	/* Variable-length IPv4 header, need to use byte-based arithmetic */
+	if (nh->pos + hdrsize > data_end)
+		return -1;
+
+	nh->pos += hdrsize;
+	*iphdr = iph;
+
+	return iph->protocol;
+}
+
+static __always_inline int parse_icmp6hdr(struct hdr_cursor *nh,
+					  void *data_end,
+					  struct icmp6hdr **icmp6hdr)
+{
+	struct icmp6hdr *icmp6h = nh->pos;
+
+	if (icmp6h + 1 > data_end)
+		return -1;
+
+	nh->pos   = icmp6h + 1;
+	*icmp6hdr = icmp6h;
+
+	return icmp6h->icmp6_type;
+}
+
+static __always_inline int parse_icmphdr(struct hdr_cursor *nh,
+					 void *data_end,
+					 struct icmphdr **icmphdr)
+{
+	struct icmphdr *icmph = nh->pos;
+
+	if (icmph + 1 > data_end)
+		return -1;
+
+	nh->pos  = icmph + 1;
+	*icmphdr = icmph;
+
+	return icmph->type;
+}
+
+static __always_inline int parse_icmphdr_common(struct hdr_cursor *nh,
+						void *data_end,
+						struct icmphdr_common **icmphdr)
+{
+	struct icmphdr_common *h = nh->pos;
+
+	if (h + 1 > data_end)
+		return -1;
+
+	nh->pos  = h + 1;
+	*icmphdr = h;
+
+	return h->type;
+}
+
+/*
+ * parse_udphdr: parse the udp header and return the length of the udp payload
+ */
+static __always_inline int parse_udphdr(struct hdr_cursor *nh,
+					void *data_end,
+					struct udphdr **udphdr)
+{
+	int len;
+	struct udphdr *h = nh->pos;
+
+	if (h + 1 > data_end)
+		return -1;
+
+	nh->pos  = h + 1;
+	*udphdr = h;
+
+	len = bpf_ntohs(h->len) - sizeof(struct udphdr);
+	if (len < 0)
+		return -1;
+
+	return len;
+}
+
+/*
+ * parse_tcphdr: parse and return the length of the tcp header
+ */
+static __always_inline int parse_tcphdr(struct hdr_cursor *nh,
+					void *data_end,
+					struct tcphdr **tcphdr)
+{
+	int len;
+	struct tcphdr *h = nh->pos;
+
+	if (h + 1 > data_end)
+		return -1;
+
+	len = h->doff * 4;
+	if ((void *) h + len > data_end)
+		return -1;
+
+	nh->pos  = h + 1;
+	*tcphdr = h;
+
+	return len;
+}
+
+#endif /* __PARSING_HELPERS_H */
diff --git a/src/xdp/common/rewrite_helpers.h b/src/xdp/common/rewrite_helpers.h
new file mode 100644
index 000000000..a5d3e671d
--- /dev/null
+++ b/src/xdp/common/rewrite_helpers.h
@@ -0,0 +1,144 @@
+/* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-clause) */
+/*
+ * This file contains functions that are used in the packetXX XDP programs to
+ * manipulate on packets data. The functions are marked as __always_inline, and
+ * fully defined in this header file to be included in the BPF program.
+ */
+
+#ifndef __REWRITE_HELPERS_H
+#define __REWRITE_HELPERS_H
+
+#include <linux/bpf.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/if_ether.h>
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+/* Pops the outermost VLAN tag off the packet. Returns the popped VLAN ID on
+ * success or negative errno on failure.
+ */
+static __always_inline int vlan_tag_pop(struct xdp_md *ctx, struct ethhdr *eth)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	struct ethhdr eth_cpy;
+	struct vlan_hdr *vlh;
+	__be16 h_proto;
+	int vlid;
+
+	if (!proto_is_vlan(eth->h_proto))
+		return -1;
+
+	/* Careful with the parenthesis here */
+	vlh = (void *)(eth + 1);
+
+	/* Still need to do bounds checking */
+	if (vlh + 1 > data_end)
+		return -1;
+
+	/* Save vlan ID for returning, h_proto for updating Ethernet header */
+	vlid = bpf_ntohs(vlh->h_vlan_TCI);
+	h_proto = vlh->h_vlan_encapsulated_proto;
+
+	/* Make a copy of the outer Ethernet header before we cut it off */
+	__builtin_memcpy(&eth_cpy, eth, sizeof(eth_cpy));
+
+	/* Actually adjust the head pointer */
+	if (bpf_xdp_adjust_head(ctx, (int)sizeof(*vlh)))
+		return -1;
+
+	/* Need to re-evaluate data *and* data_end and do new bounds checking
+	 * after adjusting head
+	 */
+	eth = (void *)(long)ctx->data;
+	data_end = (void *)(long)ctx->data_end;
+	if (eth + 1 > data_end)
+		return -1;
+
+	/* Copy back the old Ethernet header and update the proto type */
+	__builtin_memcpy(eth, &eth_cpy, sizeof(*eth));
+	eth->h_proto = h_proto;
+
+	return vlid;
+}
+
+/* Pushes a new VLAN tag after the Ethernet header. Returns 0 on success,
+ * -1 on failure.
+ */
+static __always_inline int vlan_tag_push(struct xdp_md *ctx,
+		struct ethhdr *eth, int vlid)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	struct ethhdr eth_cpy;
+	struct vlan_hdr *vlh;
+
+	/* First copy the original Ethernet header */
+	__builtin_memcpy(&eth_cpy, eth, sizeof(eth_cpy));
+
+	/* Then add space in front of the packet */
+	if (bpf_xdp_adjust_head(ctx, 0 - (int)sizeof(*vlh)))
+		return -1;
+
+	/* Need to re-evaluate data_end and data after head adjustment, and
+	 * bounds check, even though we know there is enough space (as we
+	 * increased it).
+	 */
+	data_end = (void *)(long)ctx->data_end;
+	eth = (void *)(long)ctx->data;
+
+	if (eth + 1 > data_end)
+		return -1;
+
+	/* Copy back Ethernet header in the right place, populate VLAN tag with
+	 * ID and proto, and set outer Ethernet header to VLAN type.
+	 */
+	__builtin_memcpy(eth, &eth_cpy, sizeof(*eth));
+
+	vlh = (void *)(eth + 1);
+
+	if (vlh + 1 > data_end)
+		return -1;
+
+	vlh->h_vlan_TCI = bpf_htons(vlid);
+	vlh->h_vlan_encapsulated_proto = eth->h_proto;
+
+	eth->h_proto = bpf_htons(ETH_P_8021Q);
+	return 0;
+}
+
+/*
+ * Swaps destination and source MAC addresses inside an Ethernet header
+ */
+static __always_inline void swap_src_dst_mac(struct ethhdr *eth)
+{
+	__u8 h_tmp[ETH_ALEN];
+
+	__builtin_memcpy(h_tmp, eth->h_source, ETH_ALEN);
+	__builtin_memcpy(eth->h_source, eth->h_dest, ETH_ALEN);
+	__builtin_memcpy(eth->h_dest, h_tmp, ETH_ALEN);
+}
+
+/*
+ * Swaps destination and source IPv6 addresses inside an IPv6 header
+ */
+static __always_inline void swap_src_dst_ipv6(struct ipv6hdr *ipv6)
+{
+	struct in6_addr tmp = ipv6->saddr;
+
+	ipv6->saddr = ipv6->daddr;
+	ipv6->daddr = tmp;
+}
+
+/*
+ * Swaps destination and source IPv4 addresses inside an IPv4 header
+ */
+static __always_inline void swap_src_dst_ipv4(struct iphdr *iphdr)
+{
+	__be32 tmp = iphdr->saddr;
+
+	iphdr->saddr = iphdr->daddr;
+	iphdr->daddr = tmp;
+}
+
+#endif /* __REWRITE_HELPERS_H */
diff --git a/src/xdp/common/xdp_stats_kern.h b/src/xdp/common/xdp_stats_kern.h
new file mode 100644
index 000000000..4e08551a0
--- /dev/null
+++ b/src/xdp/common/xdp_stats_kern.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Used *ONLY* by BPF-prog running kernel side. */
+#ifndef __XDP_STATS_KERN_H
+#define __XDP_STATS_KERN_H
+
+/* Data record type 'struct datarec' is defined in common/xdp_stats_kern_user.h,
+ * programs using this header must first include that file.
+ */
+#ifndef __XDP_STATS_KERN_USER_H
+#warning "You forgot to #include <../common/xdp_stats_kern_user.h>"
+#include <../common/xdp_stats_kern_user.h>
+#endif
+
+/* Keeps stats per (enum) xdp_action */
+struct bpf_map_def SEC("maps") xdp_stats_map = {
+	.type        = BPF_MAP_TYPE_PERCPU_ARRAY,
+	.key_size    = sizeof(__u32),
+	.value_size  = sizeof(struct datarec),
+	.max_entries = XDP_ACTION_MAX,
+};
+
+static __always_inline
+__u32 xdp_stats_record_action(struct xdp_md *ctx, __u32 action)
+{
+	if (action >= XDP_ACTION_MAX)
+		return XDP_ABORTED;
+
+	/* Lookup in kernel BPF-side return pointer to actual data record */
+	struct datarec *rec = bpf_map_lookup_elem(&xdp_stats_map, &action);
+	if (!rec)
+		return XDP_ABORTED;
+
+	/* BPF_MAP_TYPE_PERCPU_ARRAY returns a data record specific to current
+	 * CPU and XDP hooks runs under Softirq, which makes it safe to update
+	 * without atomic operations.
+	 */
+	rec->rx_packets++;
+	rec->rx_bytes += (ctx->data_end - ctx->data);
+
+	return action;
+}
+
+#endif /* __XDP_STATS_KERN_H */
diff --git a/src/xdp/common/xdp_stats_kern_user.h b/src/xdp/common/xdp_stats_kern_user.h
new file mode 100644
index 000000000..d7b8d05e6
--- /dev/null
+++ b/src/xdp/common/xdp_stats_kern_user.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Used by BPF-prog kernel side BPF-progs and userspace programs,
+ * for sharing xdp_stats common struct and DEFINEs.
+ */
+#ifndef __XDP_STATS_KERN_USER_H
+#define __XDP_STATS_KERN_USER_H
+
+/* This is the data record stored in the map */
+struct datarec {
+	__u64 rx_packets;
+	__u64 rx_bytes;
+};
+
+#ifndef XDP_ACTION_MAX
+#define XDP_ACTION_MAX (XDP_REDIRECT + 1)
+#endif
+
+#endif /* __XDP_STATS_KERN_USER_H */
diff --git a/src/xdp/include/bpf_endian.h b/src/xdp/include/bpf_endian.h
new file mode 100644
index 000000000..2b0ede3d5
--- /dev/null
+++ b/src/xdp/include/bpf_endian.h
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copied from $(LINUX)/tools/testing/selftests/bpf/bpf_endian.h */
+#ifndef __BPF_ENDIAN__
+#define __BPF_ENDIAN__
+
+#include <linux/swab.h>
+
+/* LLVM's BPF target selects the endianness of the CPU
+ * it compiles on, or the user specifies (bpfel/bpfeb),
+ * respectively. The used __BYTE_ORDER__ is defined by
+ * the compiler, we cannot rely on __BYTE_ORDER from
+ * libc headers, since it doesn't reflect the actual
+ * requested byte order.
+ *
+ * Note, LLVM's BPF target has different __builtin_bswapX()
+ * semantics. It does map to BPF_ALU | BPF_END | BPF_TO_BE
+ * in bpfel and bpfeb case, which means below, that we map
+ * to cpu_to_be16(). We could use it unconditionally in BPF
+ * case, but better not rely on it, so that this header here
+ * can be used from application and BPF program side, which
+ * use different targets.
+ */
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+# define __bpf_ntohs(x)__builtin_bswap16(x)
+# define __bpf_htons(x)__builtin_bswap16(x)
+# define __bpf_constant_ntohs(x)___constant_swab16(x)
+# define __bpf_constant_htons(x)___constant_swab16(x)
+# define __bpf_ntohl(x)__builtin_bswap32(x)
+# define __bpf_htonl(x)__builtin_bswap32(x)
+# define __bpf_constant_ntohl(x)___constant_swab32(x)
+# define __bpf_constant_htonl(x)___constant_swab32(x)
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+# define __bpf_ntohs(x)(x)
+# define __bpf_htons(x)(x)
+# define __bpf_constant_ntohs(x)(x)
+# define __bpf_constant_htons(x)(x)
+# define __bpf_ntohl(x)(x)
+# define __bpf_htonl(x)(x)
+# define __bpf_constant_ntohl(x)(x)
+# define __bpf_constant_htonl(x)(x)
+#else
+# error "Fix your compiler's __BYTE_ORDER__?!"
+#endif
+
+#define bpf_htons(x)\
+  (__builtin_constant_p(x) ?\
+   __bpf_constant_htons(x) : __bpf_htons(x))
+#define bpf_ntohs(x)\
+  (__builtin_constant_p(x) ?\
+   __bpf_constant_ntohs(x) : __bpf_ntohs(x))
+#define bpf_htonl(x)\
+  (__builtin_constant_p(x) ?\
+   __bpf_constant_htonl(x) : __bpf_htonl(x))
+#define bpf_ntohl(x)\
+  (__builtin_constant_p(x) ?\
+   __bpf_constant_ntohl(x) : __bpf_ntohl(x))
+
+#endif /* __BPF_ENDIAN__ */
diff --git a/src/xdp/include/bpf_legacy.h b/src/xdp/include/bpf_legacy.h
new file mode 100644
index 000000000..8dfa168cd
--- /dev/null
+++ b/src/xdp/include/bpf_legacy.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+#ifndef __BPF_LEGACY__
+#define __BPF_LEGACY__
+
+/*
+ * legacy bpf_map_def with extra fields supported only by bpf_load(), do not
+ * use outside of samples/bpf
+ */
+struct bpf_map_def_legacy {
+	unsigned int type;
+	unsigned int key_size;
+	unsigned int value_size;
+	unsigned int max_entries;
+	unsigned int map_flags;
+	unsigned int inner_map_idx;
+	unsigned int numa_node;
+};
+
+#define BPF_ANNOTATE_KV_PAIR(name, type_key, type_val)		\
+	struct ____btf_map_##name {				\
+		type_key key;					\
+		type_val value;					\
+	};							\
+	struct ____btf_map_##name				\
+	__attribute__ ((section(".maps." #name), used))		\
+		____btf_map_##name = { }
+
+/* llvm builtin functions that eBPF C program may use to
+ * emit BPF_LD_ABS and BPF_LD_IND instructions
+ */
+unsigned long long load_byte(void *skb,
+			     unsigned long long off) asm("llvm.bpf.load.byte");
+unsigned long long load_half(void *skb,
+			     unsigned long long off) asm("llvm.bpf.load.half");
+unsigned long long load_word(void *skb,
+			     unsigned long long off) asm("llvm.bpf.load.word");
+
+#endif
diff --git a/src/xdp/include/bpf_util.h b/src/xdp/include/bpf_util.h
new file mode 100644
index 000000000..e74b33e9d
--- /dev/null
+++ b/src/xdp/include/bpf_util.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copied from $(LINUX)/tools/testing/selftests/bpf/bpf_util.h */
+#ifndef __BPF_UTIL__
+#define __BPF_UTIL__
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+static inline unsigned int bpf_num_possible_cpus(void)
+{
+	static const char *fcpu = "/sys/devices/system/cpu/possible";
+	unsigned int start, end, possible_cpus = 0;
+	char buff[128];
+	FILE *fp;
+	int n;
+
+	fp = fopen(fcpu, "r");
+	if (!fp) {
+		printf("Failed to open %s: '%s'!\n", fcpu, strerror(errno));
+		exit(1);
+	}
+
+	while (fgets(buff, sizeof(buff), fp)) {
+		n = sscanf(buff, "%u-%u", &start, &end);
+		if (n == 0) {
+			printf("Failed to retrieve # possible CPUs!\n");
+			exit(1);
+		} else if (n == 1) {
+			end = start;
+		}
+		possible_cpus = start == 0 ? end + 1 : 0;
+		break;
+	}
+	fclose(fp);
+
+	return possible_cpus;
+}
+
+#define __bpf_percpu_val_align	__attribute__((__aligned__(8)))
+
+#define BPF_DECLARE_PERCPU(type, name)				\
+	struct { type v; /* padding */ } __bpf_percpu_val_align	\
+		name[bpf_num_possible_cpus()]
+#define bpf_percpu(name, cpu) name[(cpu)].v
+
+#ifndef ARRAY_SIZE
+# define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#endif
+
+#ifndef sizeof_field
+#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
+#endif
+
+#ifndef offsetofend
+#define offsetofend(TYPE, MEMBER) \
+	(offsetof(TYPE, MEMBER)	+ sizeof_field(TYPE, MEMBER))
+#endif
+
+#endif /* __BPF_UTIL__ */
diff --git a/src/xdp/include/jhash.h b/src/xdp/include/jhash.h
new file mode 100644
index 000000000..b81a0d0eb
--- /dev/null
+++ b/src/xdp/include/jhash.h
@@ -0,0 +1,172 @@
+#ifndef _LINUX_JHASH_H
+#define _LINUX_JHASH_H
+
+/* Copied from $(LINUX)/include/linux/jhash.h (kernel 4.18) */
+
+/* jhash.h: Jenkins hash support.
+ *
+ * Copyright (C) 2006. Bob Jenkins (bob_jenkins@burtleburtle.net)
+ *
+ * http://burtleburtle.net/bob/hash/
+ *
+ * These are the credits from Bob's sources:
+ *
+ * lookup3.c, by Bob Jenkins, May 2006, Public Domain.
+ *
+ * These are functions for producing 32-bit hashes for hash table lookup.
+ * hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final()
+ * are externally useful functions.  Routines to test the hash are included
+ * if SELF_TEST is defined.  You can use this free for any purpose.  It's in
+ * the public domain.  It has no warranty.
+ *
+ * Copyright (C) 2009-2010 Jozsef Kadlecsik (kadlec@blackhole.kfki.hu)
+ */
+
+static inline __u32 rol32(__u32 word, unsigned int shift)
+{
+	return (word << shift) | (word >> ((-shift) & 31));
+}
+
+/* copy paste of jhash from kernel sources (include/linux/jhash.h) to make sure
+ * LLVM can compile it into valid sequence of BPF instructions
+ */
+#define __jhash_mix(a, b, c)			\
+{						\
+	a -= c;  a ^= rol32(c, 4);  c += b;	\
+	b -= a;  b ^= rol32(a, 6);  a += c;	\
+	c -= b;  c ^= rol32(b, 8);  b += a;	\
+	a -= c;  a ^= rol32(c, 16); c += b;	\
+	b -= a;  b ^= rol32(a, 19); a += c;	\
+	c -= b;  c ^= rol32(b, 4);  b += a;	\
+}
+
+#define __jhash_final(a, b, c)			\
+{						\
+	c ^= b; c -= rol32(b, 14);		\
+	a ^= c; a -= rol32(c, 11);		\
+	b ^= a; b -= rol32(a, 25);		\
+	c ^= b; c -= rol32(b, 16);		\
+	a ^= c; a -= rol32(c, 4);		\
+	b ^= a; b -= rol32(a, 14);		\
+	c ^= b; c -= rol32(b, 24);		\
+}
+
+#define JHASH_INITVAL		0xdeadbeef
+
+typedef unsigned int u32;
+
+/* jhash - hash an arbitrary key
+ * @k: sequence of bytes as key
+ * @length: the length of the key
+ * @initval: the previous hash, or an arbitray value
+ *
+ * The generic version, hashes an arbitrary sequence of bytes.
+ * No alignment or length assumptions are made about the input key.
+ *
+ * Returns the hash value of the key. The result depends on endianness.
+ */
+static inline u32 jhash(const void *key, u32 length, u32 initval)
+{
+	u32 a, b, c;
+	const unsigned char *k = key;
+
+	/* Set up the internal state */
+	a = b = c = JHASH_INITVAL + length + initval;
+
+	/* All but the last block: affect some 32 bits of (a,b,c) */
+	while (length > 12) {
+		a += *(u32 *)(k);
+		b += *(u32 *)(k + 4);
+		c += *(u32 *)(k + 8);
+		__jhash_mix(a, b, c);
+		length -= 12;
+		k += 12;
+	}
+	/* Last block: affect all 32 bits of (c) */
+	switch (length) {
+	case 12: c += (u32)k[11]<<24;	/* fall through */
+	case 11: c += (u32)k[10]<<16;	/* fall through */
+	case 10: c += (u32)k[9]<<8;	/* fall through */
+	case 9:  c += k[8];		/* fall through */
+	case 8:  b += (u32)k[7]<<24;	/* fall through */
+	case 7:  b += (u32)k[6]<<16;	/* fall through */
+	case 6:  b += (u32)k[5]<<8;	/* fall through */
+	case 5:  b += k[4];		/* fall through */
+	case 4:  a += (u32)k[3]<<24;	/* fall through */
+	case 3:  a += (u32)k[2]<<16;	/* fall through */
+	case 2:  a += (u32)k[1]<<8;	/* fall through */
+	case 1:  a += k[0];
+		 __jhash_final(a, b, c);
+	case 0: /* Nothing left to add */
+		break;
+	}
+
+	return c;
+}
+
+/* jhash2 - hash an array of u32's
+ * @k: the key which must be an array of u32's
+ * @length: the number of u32's in the key
+ * @initval: the previous hash, or an arbitray value
+ *
+ * Returns the hash value of the key.
+ */
+static inline u32 jhash2(const u32 *k, u32 length, u32 initval)
+{
+	u32 a, b, c;
+
+	/* Set up the internal state */
+	a = b = c = JHASH_INITVAL + (length<<2) + initval;
+
+	/* Handle most of the key */
+	while (length > 3) {
+		a += k[0];
+		b += k[1];
+		c += k[2];
+		__jhash_mix(a, b, c);
+		length -= 3;
+		k += 3;
+	}
+
+	/* Handle the last 3 u32's */
+	switch (length) {
+	case 3: c += k[2];	/* fall through */
+	case 2: b += k[1];	/* fall through */
+	case 1: a += k[0];
+		__jhash_final(a, b, c);
+	case 0:	/* Nothing left to add */
+		break;
+	}
+
+	return c;
+}
+
+
+/* __jhash_nwords - hash exactly 3, 2 or 1 word(s) */
+static inline u32 __jhash_nwords(u32 a, u32 b, u32 c, u32 initval)
+{
+	a += initval;
+	b += initval;
+	c += initval;
+
+	__jhash_final(a, b, c);
+
+	return c;
+}
+
+static inline u32 jhash_3words(u32 a, u32 b, u32 c, u32 initval)
+{
+	return __jhash_nwords(a, b, c, initval + JHASH_INITVAL + (3 << 2));
+}
+
+static inline u32 jhash_2words(u32 a, u32 b, u32 initval)
+{
+	return __jhash_nwords(a, b, 0, initval + JHASH_INITVAL + (2 << 2));
+}
+
+static inline u32 jhash_1word(u32 a, u32 initval)
+{
+	return __jhash_nwords(a, 0, 0, initval + JHASH_INITVAL + (1 << 2));
+}
+
+#endif /* _LINUX_JHASH_H */
diff --git a/src/xdp/include/linux/bpf.h b/src/xdp/include/linux/bpf.h
new file mode 100644
index 000000000..161a93809
--- /dev/null
+++ b/src/xdp/include/linux/bpf.h
@@ -0,0 +1,3278 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#ifndef _UAPI__LINUX_BPF_H__
+#define _UAPI__LINUX_BPF_H__
+
+#include <linux/types.h>
+#include <linux/bpf_common.h>
+
+/* Extended instruction set based on top of classic BPF */
+
+/* instruction classes */
+#define BPF_JMP32	0x06	/* jmp mode in word width */
+#define BPF_ALU64	0x07	/* alu mode in double word width */
+
+/* ld/ldx fields */
+#define BPF_DW		0x18	/* double word (64-bit) */
+#define BPF_XADD	0xc0	/* exclusive add */
+
+/* alu/jmp fields */
+#define BPF_MOV		0xb0	/* mov reg to reg */
+#define BPF_ARSH	0xc0	/* sign extending arithmetic shift right */
+
+/* change endianness of a register */
+#define BPF_END		0xd0	/* flags for endianness conversion: */
+#define BPF_TO_LE	0x00	/* convert to little-endian */
+#define BPF_TO_BE	0x08	/* convert to big-endian */
+#define BPF_FROM_LE	BPF_TO_LE
+#define BPF_FROM_BE	BPF_TO_BE
+
+/* jmp encodings */
+#define BPF_JNE		0x50	/* jump != */
+#define BPF_JLT		0xa0	/* LT is unsigned, '<' */
+#define BPF_JLE		0xb0	/* LE is unsigned, '<=' */
+#define BPF_JSGT	0x60	/* SGT is signed '>', GT in x86 */
+#define BPF_JSGE	0x70	/* SGE is signed '>=', GE in x86 */
+#define BPF_JSLT	0xc0	/* SLT is signed, '<' */
+#define BPF_JSLE	0xd0	/* SLE is signed, '<=' */
+#define BPF_CALL	0x80	/* function call */
+#define BPF_EXIT	0x90	/* function return */
+
+/* Register numbers */
+enum {
+	BPF_REG_0 = 0,
+	BPF_REG_1,
+	BPF_REG_2,
+	BPF_REG_3,
+	BPF_REG_4,
+	BPF_REG_5,
+	BPF_REG_6,
+	BPF_REG_7,
+	BPF_REG_8,
+	BPF_REG_9,
+	BPF_REG_10,
+	__MAX_BPF_REG,
+};
+
+/* BPF has 10 general purpose 64-bit registers and stack frame. */
+#define MAX_BPF_REG	__MAX_BPF_REG
+
+struct bpf_insn {
+	__u8	code;		/* opcode */
+	__u8	dst_reg:4;	/* dest register */
+	__u8	src_reg:4;	/* source register */
+	__s16	off;		/* signed offset */
+	__s32	imm;		/* signed immediate constant */
+};
+
+/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
+struct bpf_lpm_trie_key {
+	__u32	prefixlen;	/* up to 32 for AF_INET, 128 for AF_INET6 */
+	__u8	data[0];	/* Arbitrary size */
+};
+
+struct bpf_cgroup_storage_key {
+	__u64	cgroup_inode_id;	/* cgroup inode id */
+	__u32	attach_type;		/* program attach type */
+};
+
+/* BPF syscall commands, see bpf(2) man-page for details. */
+enum bpf_cmd {
+	BPF_MAP_CREATE,
+	BPF_MAP_LOOKUP_ELEM,
+	BPF_MAP_UPDATE_ELEM,
+	BPF_MAP_DELETE_ELEM,
+	BPF_MAP_GET_NEXT_KEY,
+	BPF_PROG_LOAD,
+	BPF_OBJ_PIN,
+	BPF_OBJ_GET,
+	BPF_PROG_ATTACH,
+	BPF_PROG_DETACH,
+	BPF_PROG_TEST_RUN,
+	BPF_PROG_GET_NEXT_ID,
+	BPF_MAP_GET_NEXT_ID,
+	BPF_PROG_GET_FD_BY_ID,
+	BPF_MAP_GET_FD_BY_ID,
+	BPF_OBJ_GET_INFO_BY_FD,
+	BPF_PROG_QUERY,
+	BPF_RAW_TRACEPOINT_OPEN,
+	BPF_BTF_LOAD,
+	BPF_BTF_GET_FD_BY_ID,
+	BPF_TASK_FD_QUERY,
+	BPF_MAP_LOOKUP_AND_DELETE_ELEM,
+};
+
+enum bpf_map_type {
+	BPF_MAP_TYPE_UNSPEC,
+	BPF_MAP_TYPE_HASH,
+	BPF_MAP_TYPE_ARRAY,
+	BPF_MAP_TYPE_PROG_ARRAY,
+	BPF_MAP_TYPE_PERF_EVENT_ARRAY,
+	BPF_MAP_TYPE_PERCPU_HASH,
+	BPF_MAP_TYPE_PERCPU_ARRAY,
+	BPF_MAP_TYPE_STACK_TRACE,
+	BPF_MAP_TYPE_CGROUP_ARRAY,
+	BPF_MAP_TYPE_LRU_HASH,
+	BPF_MAP_TYPE_LRU_PERCPU_HASH,
+	BPF_MAP_TYPE_LPM_TRIE,
+	BPF_MAP_TYPE_ARRAY_OF_MAPS,
+	BPF_MAP_TYPE_HASH_OF_MAPS,
+	BPF_MAP_TYPE_DEVMAP,
+	BPF_MAP_TYPE_SOCKMAP,
+	BPF_MAP_TYPE_CPUMAP,
+	BPF_MAP_TYPE_XSKMAP,
+	BPF_MAP_TYPE_SOCKHASH,
+	BPF_MAP_TYPE_CGROUP_STORAGE,
+	BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
+	BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE,
+	BPF_MAP_TYPE_QUEUE,
+	BPF_MAP_TYPE_STACK,
+};
+
+/* Note that tracing related programs such as
+ * BPF_PROG_TYPE_{KPROBE,TRACEPOINT,PERF_EVENT,RAW_TRACEPOINT}
+ * are not subject to a stable API since kernel internal data
+ * structures can change from release to release and may
+ * therefore break existing tracing BPF programs. Tracing BPF
+ * programs correspond to /a/ specific kernel which is to be
+ * analyzed, and not /a/ specific kernel /and/ all future ones.
+ */
+enum bpf_prog_type {
+	BPF_PROG_TYPE_UNSPEC,
+	BPF_PROG_TYPE_SOCKET_FILTER,
+	BPF_PROG_TYPE_KPROBE,
+	BPF_PROG_TYPE_SCHED_CLS,
+	BPF_PROG_TYPE_SCHED_ACT,
+	BPF_PROG_TYPE_TRACEPOINT,
+	BPF_PROG_TYPE_XDP,
+	BPF_PROG_TYPE_PERF_EVENT,
+	BPF_PROG_TYPE_CGROUP_SKB,
+	BPF_PROG_TYPE_CGROUP_SOCK,
+	BPF_PROG_TYPE_LWT_IN,
+	BPF_PROG_TYPE_LWT_OUT,
+	BPF_PROG_TYPE_LWT_XMIT,
+	BPF_PROG_TYPE_SOCK_OPS,
+	BPF_PROG_TYPE_SK_SKB,
+	BPF_PROG_TYPE_CGROUP_DEVICE,
+	BPF_PROG_TYPE_SK_MSG,
+	BPF_PROG_TYPE_RAW_TRACEPOINT,
+	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+	BPF_PROG_TYPE_LWT_SEG6LOCAL,
+	BPF_PROG_TYPE_LIRC_MODE2,
+	BPF_PROG_TYPE_SK_REUSEPORT,
+	BPF_PROG_TYPE_FLOW_DISSECTOR,
+};
+
+enum bpf_attach_type {
+	BPF_CGROUP_INET_INGRESS,
+	BPF_CGROUP_INET_EGRESS,
+	BPF_CGROUP_INET_SOCK_CREATE,
+	BPF_CGROUP_SOCK_OPS,
+	BPF_SK_SKB_STREAM_PARSER,
+	BPF_SK_SKB_STREAM_VERDICT,
+	BPF_CGROUP_DEVICE,
+	BPF_SK_MSG_VERDICT,
+	BPF_CGROUP_INET4_BIND,
+	BPF_CGROUP_INET6_BIND,
+	BPF_CGROUP_INET4_CONNECT,
+	BPF_CGROUP_INET6_CONNECT,
+	BPF_CGROUP_INET4_POST_BIND,
+	BPF_CGROUP_INET6_POST_BIND,
+	BPF_CGROUP_UDP4_SENDMSG,
+	BPF_CGROUP_UDP6_SENDMSG,
+	BPF_LIRC_MODE2,
+	BPF_FLOW_DISSECTOR,
+	__MAX_BPF_ATTACH_TYPE
+};
+
+#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
+
+/* cgroup-bpf attach flags used in BPF_PROG_ATTACH command
+ *
+ * NONE(default): No further bpf programs allowed in the subtree.
+ *
+ * BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program,
+ * the program in this cgroup yields to sub-cgroup program.
+ *
+ * BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program,
+ * that cgroup program gets run in addition to the program in this cgroup.
+ *
+ * Only one program is allowed to be attached to a cgroup with
+ * NONE or BPF_F_ALLOW_OVERRIDE flag.
+ * Attaching another program on top of NONE or BPF_F_ALLOW_OVERRIDE will
+ * release old program and attach the new one. Attach flags has to match.
+ *
+ * Multiple programs are allowed to be attached to a cgroup with
+ * BPF_F_ALLOW_MULTI flag. They are executed in FIFO order
+ * (those that were attached first, run first)
+ * The programs of sub-cgroup are executed first, then programs of
+ * this cgroup and then programs of parent cgroup.
+ * When children program makes decision (like picking TCP CA or sock bind)
+ * parent program has a chance to override it.
+ *
+ * A cgroup with MULTI or OVERRIDE flag allows any attach flags in sub-cgroups.
+ * A cgroup with NONE doesn't allow any programs in sub-cgroups.
+ * Ex1:
+ * cgrp1 (MULTI progs A, B) ->
+ *    cgrp2 (OVERRIDE prog C) ->
+ *      cgrp3 (MULTI prog D) ->
+ *        cgrp4 (OVERRIDE prog E) ->
+ *          cgrp5 (NONE prog F)
+ * the event in cgrp5 triggers execution of F,D,A,B in that order.
+ * if prog F is detached, the execution is E,D,A,B
+ * if prog F and D are detached, the execution is E,A,B
+ * if prog F, E and D are detached, the execution is C,A,B
+ *
+ * All eligible programs are executed regardless of return code from
+ * earlier programs.
+ */
+#define BPF_F_ALLOW_OVERRIDE	(1U << 0)
+#define BPF_F_ALLOW_MULTI	(1U << 1)
+
+/* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the
+ * verifier will perform strict alignment checking as if the kernel
+ * has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set,
+ * and NET_IP_ALIGN defined to 2.
+ */
+#define BPF_F_STRICT_ALIGNMENT	(1U << 0)
+
+/* If BPF_F_ANY_ALIGNMENT is used in BPF_PROF_LOAD command, the
+ * verifier will allow any alignment whatsoever.  On platforms
+ * with strict alignment requirements for loads ands stores (such
+ * as sparc and mips) the verifier validates that all loads and
+ * stores provably follow this requirement.  This flag turns that
+ * checking and enforcement off.
+ *
+ * It is mostly used for testing when we want to validate the
+ * context and memory access aspects of the verifier, but because
+ * of an unaligned access the alignment check would trigger before
+ * the one we are interested in.
+ */
+#define BPF_F_ANY_ALIGNMENT	(1U << 1)
+
+/* when bpf_ldimm64->src_reg == BPF_PSEUDO_MAP_FD, bpf_ldimm64->imm == fd */
+#define BPF_PSEUDO_MAP_FD	1
+
+/* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative
+ * offset to another bpf function
+ */
+#define BPF_PSEUDO_CALL		1
+
+/* flags for BPF_MAP_UPDATE_ELEM command */
+#define BPF_ANY		0 /* create new element or update existing */
+#define BPF_NOEXIST	1 /* create new element if it didn't exist */
+#define BPF_EXIST	2 /* update existing element */
+#define BPF_F_LOCK	4 /* spin_lock-ed map_lookup/map_update */
+
+/* flags for BPF_MAP_CREATE command */
+#define BPF_F_NO_PREALLOC	(1U << 0)
+/* Instead of having one common LRU list in the
+ * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
+ * which can scale and perform better.
+ * Note, the LRU nodes (including free nodes) cannot be moved
+ * across different LRU lists.
+ */
+#define BPF_F_NO_COMMON_LRU	(1U << 1)
+/* Specify numa node during map creation */
+#define BPF_F_NUMA_NODE		(1U << 2)
+
+#define BPF_OBJ_NAME_LEN 16U
+
+/* Flags for accessing BPF object */
+#define BPF_F_RDONLY		(1U << 3)
+#define BPF_F_WRONLY		(1U << 4)
+
+/* Flag for stack_map, store build_id+offset instead of pointer */
+#define BPF_F_STACK_BUILD_ID	(1U << 5)
+
+/* Zero-initialize hash function seed. This should only be used for testing. */
+#define BPF_F_ZERO_SEED		(1U << 6)
+
+/* flags for BPF_PROG_QUERY */
+#define BPF_F_QUERY_EFFECTIVE	(1U << 0)
+
+enum bpf_stack_build_id_status {
+	/* user space need an empty entry to identify end of a trace */
+	BPF_STACK_BUILD_ID_EMPTY = 0,
+	/* with valid build_id and offset */
+	BPF_STACK_BUILD_ID_VALID = 1,
+	/* couldn't get build_id, fallback to ip */
+	BPF_STACK_BUILD_ID_IP = 2,
+};
+
+#define BPF_BUILD_ID_SIZE 20
+struct bpf_stack_build_id {
+	__s32		status;
+	unsigned char	build_id[BPF_BUILD_ID_SIZE];
+	union {
+		__u64	offset;
+		__u64	ip;
+	};
+};
+
+union bpf_attr {
+	struct { /* anonymous struct used by BPF_MAP_CREATE command */
+		__u32	map_type;	/* one of enum bpf_map_type */
+		__u32	key_size;	/* size of key in bytes */
+		__u32	value_size;	/* size of value in bytes */
+		__u32	max_entries;	/* max number of entries in a map */
+		__u32	map_flags;	/* BPF_MAP_CREATE related
+					 * flags defined above.
+					 */
+		__u32	inner_map_fd;	/* fd pointing to the inner map */
+		__u32	numa_node;	/* numa node (effective only if
+					 * BPF_F_NUMA_NODE is set).
+					 */
+		char	map_name[BPF_OBJ_NAME_LEN];
+		__u32	map_ifindex;	/* ifindex of netdev to create on */
+		__u32	btf_fd;		/* fd pointing to a BTF type data */
+		__u32	btf_key_type_id;	/* BTF type_id of the key */
+		__u32	btf_value_type_id;	/* BTF type_id of the value */
+	};
+
+	struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
+		__u32		map_fd;
+		__aligned_u64	key;
+		union {
+			__aligned_u64 value;
+			__aligned_u64 next_key;
+		};
+		__u64		flags;
+	};
+
+	struct { /* anonymous struct used by BPF_PROG_LOAD command */
+		__u32		prog_type;	/* one of enum bpf_prog_type */
+		__u32		insn_cnt;
+		__aligned_u64	insns;
+		__aligned_u64	license;
+		__u32		log_level;	/* verbosity level of verifier */
+		__u32		log_size;	/* size of user buffer */
+		__aligned_u64	log_buf;	/* user supplied buffer */
+		__u32		kern_version;	/* not used */
+		__u32		prog_flags;
+		char		prog_name[BPF_OBJ_NAME_LEN];
+		__u32		prog_ifindex;	/* ifindex of netdev to prep for */
+		/* For some prog types expected attach type must be known at
+		 * load time to verify attach type specific parts of prog
+		 * (context accesses, allowed helpers, etc).
+		 */
+		__u32		expected_attach_type;
+		__u32		prog_btf_fd;	/* fd pointing to BTF type data */
+		__u32		func_info_rec_size;	/* userspace bpf_func_info size */
+		__aligned_u64	func_info;	/* func info */
+		__u32		func_info_cnt;	/* number of bpf_func_info records */
+		__u32		line_info_rec_size;	/* userspace bpf_line_info size */
+		__aligned_u64	line_info;	/* line info */
+		__u32		line_info_cnt;	/* number of bpf_line_info records */
+	};
+
+	struct { /* anonymous struct used by BPF_OBJ_* commands */
+		__aligned_u64	pathname;
+		__u32		bpf_fd;
+		__u32		file_flags;
+	};
+
+	struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH commands */
+		__u32		target_fd;	/* container object to attach to */
+		__u32		attach_bpf_fd;	/* eBPF program to attach */
+		__u32		attach_type;
+		__u32		attach_flags;
+	};
+
+	struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
+		__u32		prog_fd;
+		__u32		retval;
+		__u32		data_size_in;	/* input: len of data_in */
+		__u32		data_size_out;	/* input/output: len of data_out
+						 *   returns ENOSPC if data_out
+						 *   is too small.
+						 */
+		__aligned_u64	data_in;
+		__aligned_u64	data_out;
+		__u32		repeat;
+		__u32		duration;
+	} test;
+
+	struct { /* anonymous struct used by BPF_*_GET_*_ID */
+		union {
+			__u32		start_id;
+			__u32		prog_id;
+			__u32		map_id;
+			__u32		btf_id;
+		};
+		__u32		next_id;
+		__u32		open_flags;
+	};
+
+	struct { /* anonymous struct used by BPF_OBJ_GET_INFO_BY_FD */
+		__u32		bpf_fd;
+		__u32		info_len;
+		__aligned_u64	info;
+	} info;
+
+	struct { /* anonymous struct used by BPF_PROG_QUERY command */
+		__u32		target_fd;	/* container object to query */
+		__u32		attach_type;
+		__u32		query_flags;
+		__u32		attach_flags;
+		__aligned_u64	prog_ids;
+		__u32		prog_cnt;
+	} query;
+
+	struct {
+		__u64 name;
+		__u32 prog_fd;
+	} raw_tracepoint;
+
+	struct { /* anonymous struct for BPF_BTF_LOAD */
+		__aligned_u64	btf;
+		__aligned_u64	btf_log_buf;
+		__u32		btf_size;
+		__u32		btf_log_size;
+		__u32		btf_log_level;
+	};
+
+	struct {
+		__u32		pid;		/* input: pid */
+		__u32		fd;		/* input: fd */
+		__u32		flags;		/* input: flags */
+		__u32		buf_len;	/* input/output: buf len */
+		__aligned_u64	buf;		/* input/output:
+						 *   tp_name for tracepoint
+						 *   symbol for kprobe
+						 *   filename for uprobe
+						 */
+		__u32		prog_id;	/* output: prod_id */
+		__u32		fd_type;	/* output: BPF_FD_TYPE_* */
+		__u64		probe_offset;	/* output: probe_offset */
+		__u64		probe_addr;	/* output: probe_addr */
+	} task_fd_query;
+} __attribute__((aligned(8)));
+
+/* The description below is an attempt at providing documentation to eBPF
+ * developers about the multiple available eBPF helper functions. It can be
+ * parsed and used to produce a manual page. The workflow is the following,
+ * and requires the rst2man utility:
+ *
+ *     $ ./scripts/bpf_helpers_doc.py \
+ *             --filename include/uapi/linux/bpf.h > /tmp/bpf-helpers.rst
+ *     $ rst2man /tmp/bpf-helpers.rst > /tmp/bpf-helpers.7
+ *     $ man /tmp/bpf-helpers.7
+ *
+ * Note that in order to produce this external documentation, some RST
+ * formatting is used in the descriptions to get "bold" and "italics" in
+ * manual pages. Also note that the few trailing white spaces are
+ * intentional, removing them would break paragraphs for rst2man.
+ *
+ * Start of BPF helper function descriptions:
+ *
+ * void *bpf_map_lookup_elem(struct bpf_map *map, const void *key)
+ * 	Description
+ * 		Perform a lookup in *map* for an entry associated to *key*.
+ * 	Return
+ * 		Map value associated to *key*, or **NULL** if no entry was
+ * 		found.
+ *
+ * int bpf_map_update_elem(struct bpf_map *map, const void *key, const void *value, u64 flags)
+ * 	Description
+ * 		Add or update the value of the entry associated to *key* in
+ * 		*map* with *value*. *flags* is one of:
+ *
+ * 		**BPF_NOEXIST**
+ * 			The entry for *key* must not exist in the map.
+ * 		**BPF_EXIST**
+ * 			The entry for *key* must already exist in the map.
+ * 		**BPF_ANY**
+ * 			No condition on the existence of the entry for *key*.
+ *
+ * 		Flag value **BPF_NOEXIST** cannot be used for maps of types
+ * 		**BPF_MAP_TYPE_ARRAY** or **BPF_MAP_TYPE_PERCPU_ARRAY**  (all
+ * 		elements always exist), the helper would return an error.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_map_delete_elem(struct bpf_map *map, const void *key)
+ * 	Description
+ * 		Delete entry with *key* from *map*.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_probe_read(void *dst, u32 size, const void *src)
+ * 	Description
+ * 		For tracing programs, safely attempt to read *size* bytes from
+ * 		address *src* and store the data in *dst*.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_ktime_get_ns(void)
+ * 	Description
+ * 		Return the time elapsed since system boot, in nanoseconds.
+ * 	Return
+ * 		Current *ktime*.
+ *
+ * int bpf_trace_printk(const char *fmt, u32 fmt_size, ...)
+ * 	Description
+ * 		This helper is a "printk()-like" facility for debugging. It
+ * 		prints a message defined by format *fmt* (of size *fmt_size*)
+ * 		to file *\/sys/kernel/debug/tracing/trace* from DebugFS, if
+ * 		available. It can take up to three additional **u64**
+ * 		arguments (as an eBPF helpers, the total number of arguments is
+ * 		limited to five).
+ *
+ * 		Each time the helper is called, it appends a line to the trace.
+ * 		The format of the trace is customizable, and the exact output
+ * 		one will get depends on the options set in
+ * 		*\/sys/kernel/debug/tracing/trace_options* (see also the
+ * 		*README* file under the same directory). However, it usually
+ * 		defaults to something like:
+ *
+ * 		::
+ *
+ * 			telnet-470   [001] .N.. 419421.045894: 0x00000001: <formatted msg>
+ *
+ * 		In the above:
+ *
+ * 			* ``telnet`` is the name of the current task.
+ * 			* ``470`` is the PID of the current task.
+ * 			* ``001`` is the CPU number on which the task is
+ * 			  running.
+ * 			* In ``.N..``, each character refers to a set of
+ * 			  options (whether irqs are enabled, scheduling
+ * 			  options, whether hard/softirqs are running, level of
+ * 			  preempt_disabled respectively). **N** means that
+ * 			  **TIF_NEED_RESCHED** and **PREEMPT_NEED_RESCHED**
+ * 			  are set.
+ * 			* ``419421.045894`` is a timestamp.
+ * 			* ``0x00000001`` is a fake value used by BPF for the
+ * 			  instruction pointer register.
+ * 			* ``<formatted msg>`` is the message formatted with
+ * 			  *fmt*.
+ *
+ * 		The conversion specifiers supported by *fmt* are similar, but
+ * 		more limited than for printk(). They are **%d**, **%i**,
+ * 		**%u**, **%x**, **%ld**, **%li**, **%lu**, **%lx**, **%lld**,
+ * 		**%lli**, **%llu**, **%llx**, **%p**, **%s**. No modifier (size
+ * 		of field, padding with zeroes, etc.) is available, and the
+ * 		helper will return **-EINVAL** (but print nothing) if it
+ * 		encounters an unknown specifier.
+ *
+ * 		Also, note that **bpf_trace_printk**\ () is slow, and should
+ * 		only be used for debugging purposes. For this reason, a notice
+ * 		bloc (spanning several lines) is printed to kernel logs and
+ * 		states that the helper should not be used "for production use"
+ * 		the first time this helper is used (or more precisely, when
+ * 		**trace_printk**\ () buffers are allocated). For passing values
+ * 		to user space, perf events should be preferred.
+ * 	Return
+ * 		The number of bytes written to the buffer, or a negative error
+ * 		in case of failure.
+ *
+ * u32 bpf_get_prandom_u32(void)
+ * 	Description
+ * 		Get a pseudo-random number.
+ *
+ * 		From a security point of view, this helper uses its own
+ * 		pseudo-random internal state, and cannot be used to infer the
+ * 		seed of other random functions in the kernel. However, it is
+ * 		essential to note that the generator used by the helper is not
+ * 		cryptographically secure.
+ * 	Return
+ * 		A random 32-bit unsigned value.
+ *
+ * u32 bpf_get_smp_processor_id(void)
+ * 	Description
+ * 		Get the SMP (symmetric multiprocessing) processor id. Note that
+ * 		all programs run with preemption disabled, which means that the
+ * 		SMP processor id is stable during all the execution of the
+ * 		program.
+ * 	Return
+ * 		The SMP id of the processor running the program.
+ *
+ * int bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len, u64 flags)
+ * 	Description
+ * 		Store *len* bytes from address *from* into the packet
+ * 		associated to *skb*, at *offset*. *flags* are a combination of
+ * 		**BPF_F_RECOMPUTE_CSUM** (automatically recompute the
+ * 		checksum for the packet after storing the bytes) and
+ * 		**BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\
+ * 		**->swhash** and *skb*\ **->l4hash** to 0).
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_l3_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 size)
+ * 	Description
+ * 		Recompute the layer 3 (e.g. IP) checksum for the packet
+ * 		associated to *skb*. Computation is incremental, so the helper
+ * 		must know the former value of the header field that was
+ * 		modified (*from*), the new value of this field (*to*), and the
+ * 		number of bytes (2 or 4) for this field, stored in *size*.
+ * 		Alternatively, it is possible to store the difference between
+ * 		the previous and the new values of the header field in *to*, by
+ * 		setting *from* and *size* to 0. For both methods, *offset*
+ * 		indicates the location of the IP checksum within the packet.
+ *
+ * 		This helper works in combination with **bpf_csum_diff**\ (),
+ * 		which does not update the checksum in-place, but offers more
+ * 		flexibility and can handle sizes larger than 2 or 4 for the
+ * 		checksum to update.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_l4_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 flags)
+ * 	Description
+ * 		Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the
+ * 		packet associated to *skb*. Computation is incremental, so the
+ * 		helper must know the former value of the header field that was
+ * 		modified (*from*), the new value of this field (*to*), and the
+ * 		number of bytes (2 or 4) for this field, stored on the lowest
+ * 		four bits of *flags*. Alternatively, it is possible to store
+ * 		the difference between the previous and the new values of the
+ * 		header field in *to*, by setting *from* and the four lowest
+ * 		bits of *flags* to 0. For both methods, *offset* indicates the
+ * 		location of the IP checksum within the packet. In addition to
+ * 		the size of the field, *flags* can be added (bitwise OR) actual
+ * 		flags. With **BPF_F_MARK_MANGLED_0**, a null checksum is left
+ * 		untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and
+ * 		for updates resulting in a null checksum the value is set to
+ * 		**CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates
+ * 		the checksum is to be computed against a pseudo-header.
+ *
+ * 		This helper works in combination with **bpf_csum_diff**\ (),
+ * 		which does not update the checksum in-place, but offers more
+ * 		flexibility and can handle sizes larger than 2 or 4 for the
+ * 		checksum to update.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_tail_call(void *ctx, struct bpf_map *prog_array_map, u32 index)
+ * 	Description
+ * 		This special helper is used to trigger a "tail call", or in
+ * 		other words, to jump into another eBPF program. The same stack
+ * 		frame is used (but values on stack and in registers for the
+ * 		caller are not accessible to the callee). This mechanism allows
+ * 		for program chaining, either for raising the maximum number of
+ * 		available eBPF instructions, or to execute given programs in
+ * 		conditional blocks. For security reasons, there is an upper
+ * 		limit to the number of successive tail calls that can be
+ * 		performed.
+ *
+ * 		Upon call of this helper, the program attempts to jump into a
+ * 		program referenced at index *index* in *prog_array_map*, a
+ * 		special map of type **BPF_MAP_TYPE_PROG_ARRAY**, and passes
+ * 		*ctx*, a pointer to the context.
+ *
+ * 		If the call succeeds, the kernel immediately runs the first
+ * 		instruction of the new program. This is not a function call,
+ * 		and it never returns to the previous program. If the call
+ * 		fails, then the helper has no effect, and the caller continues
+ * 		to run its subsequent instructions. A call can fail if the
+ * 		destination program for the jump does not exist (i.e. *index*
+ * 		is superior to the number of entries in *prog_array_map*), or
+ * 		if the maximum number of tail calls has been reached for this
+ * 		chain of programs. This limit is defined in the kernel by the
+ * 		macro **MAX_TAIL_CALL_CNT** (not accessible to user space),
+ * 		which is currently set to 32.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_clone_redirect(struct sk_buff *skb, u32 ifindex, u64 flags)
+ * 	Description
+ * 		Clone and redirect the packet associated to *skb* to another
+ * 		net device of index *ifindex*. Both ingress and egress
+ * 		interfaces can be used for redirection. The **BPF_F_INGRESS**
+ * 		value in *flags* is used to make the distinction (ingress path
+ * 		is selected if the flag is present, egress path otherwise).
+ * 		This is the only flag supported for now.
+ *
+ * 		In comparison with **bpf_redirect**\ () helper,
+ * 		**bpf_clone_redirect**\ () has the associated cost of
+ * 		duplicating the packet buffer, but this can be executed out of
+ * 		the eBPF program. Conversely, **bpf_redirect**\ () is more
+ * 		efficient, but it is handled through an action code where the
+ * 		redirection happens only after the eBPF program has returned.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_get_current_pid_tgid(void)
+ * 	Return
+ * 		A 64-bit integer containing the current tgid and pid, and
+ * 		created as such:
+ * 		*current_task*\ **->tgid << 32 \|**
+ * 		*current_task*\ **->pid**.
+ *
+ * u64 bpf_get_current_uid_gid(void)
+ * 	Return
+ * 		A 64-bit integer containing the current GID and UID, and
+ * 		created as such: *current_gid* **<< 32 \|** *current_uid*.
+ *
+ * int bpf_get_current_comm(char *buf, u32 size_of_buf)
+ * 	Description
+ * 		Copy the **comm** attribute of the current task into *buf* of
+ * 		*size_of_buf*. The **comm** attribute contains the name of
+ * 		the executable (excluding the path) for the current task. The
+ * 		*size_of_buf* must be strictly positive. On success, the
+ * 		helper makes sure that the *buf* is NUL-terminated. On failure,
+ * 		it is filled with zeroes.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * u32 bpf_get_cgroup_classid(struct sk_buff *skb)
+ * 	Description
+ * 		Retrieve the classid for the current task, i.e. for the net_cls
+ * 		cgroup to which *skb* belongs.
+ *
+ * 		This helper can be used on TC egress path, but not on ingress.
+ *
+ * 		The net_cls cgroup provides an interface to tag network packets
+ * 		based on a user-provided identifier for all traffic coming from
+ * 		the tasks belonging to the related cgroup. See also the related
+ * 		kernel documentation, available from the Linux sources in file
+ * 		*Documentation/cgroup-v1/net_cls.txt*.
+ *
+ * 		The Linux kernel has two versions for cgroups: there are
+ * 		cgroups v1 and cgroups v2. Both are available to users, who can
+ * 		use a mixture of them, but note that the net_cls cgroup is for
+ * 		cgroup v1 only. This makes it incompatible with BPF programs
+ * 		run on cgroups, which is a cgroup-v2-only feature (a socket can
+ * 		only hold data for one version of cgroups at a time).
+ *
+ * 		This helper is only available is the kernel was compiled with
+ * 		the **CONFIG_CGROUP_NET_CLASSID** configuration option set to
+ * 		"**y**" or to "**m**".
+ * 	Return
+ * 		The classid, or 0 for the default unconfigured classid.
+ *
+ * int bpf_skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
+ * 	Description
+ * 		Push a *vlan_tci* (VLAN tag control information) of protocol
+ * 		*vlan_proto* to the packet associated to *skb*, then update
+ * 		the checksum. Note that if *vlan_proto* is different from
+ * 		**ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to
+ * 		be **ETH_P_8021Q**.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_vlan_pop(struct sk_buff *skb)
+ * 	Description
+ * 		Pop a VLAN header from the packet associated to *skb*.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_get_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags)
+ * 	Description
+ * 		Get tunnel metadata. This helper takes a pointer *key* to an
+ * 		empty **struct bpf_tunnel_key** of **size**, that will be
+ * 		filled with tunnel metadata for the packet associated to *skb*.
+ * 		The *flags* can be set to **BPF_F_TUNINFO_IPV6**, which
+ * 		indicates that the tunnel is based on IPv6 protocol instead of
+ * 		IPv4.
+ *
+ * 		The **struct bpf_tunnel_key** is an object that generalizes the
+ * 		principal parameters used by various tunneling protocols into a
+ * 		single struct. This way, it can be used to easily make a
+ * 		decision based on the contents of the encapsulation header,
+ * 		"summarized" in this struct. In particular, it holds the IP
+ * 		address of the remote end (IPv4 or IPv6, depending on the case)
+ * 		in *key*\ **->remote_ipv4** or *key*\ **->remote_ipv6**. Also,
+ * 		this struct exposes the *key*\ **->tunnel_id**, which is
+ * 		generally mapped to a VNI (Virtual Network Identifier), making
+ * 		it programmable together with the **bpf_skb_set_tunnel_key**\
+ * 		() helper.
+ *
+ * 		Let's imagine that the following code is part of a program
+ * 		attached to the TC ingress interface, on one end of a GRE
+ * 		tunnel, and is supposed to filter out all messages coming from
+ * 		remote ends with IPv4 address other than 10.0.0.1:
+ *
+ * 		::
+ *
+ * 			int ret;
+ * 			struct bpf_tunnel_key key = {};
+ *
+ * 			ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
+ * 			if (ret < 0)
+ * 				return TC_ACT_SHOT;	// drop packet
+ *
+ * 			if (key.remote_ipv4 != 0x0a000001)
+ * 				return TC_ACT_SHOT;	// drop packet
+ *
+ * 			return TC_ACT_OK;		// accept packet
+ *
+ * 		This interface can also be used with all encapsulation devices
+ * 		that can operate in "collect metadata" mode: instead of having
+ * 		one network device per specific configuration, the "collect
+ * 		metadata" mode only requires a single device where the
+ * 		configuration can be extracted from this helper.
+ *
+ * 		This can be used together with various tunnels such as VXLan,
+ * 		Geneve, GRE or IP in IP (IPIP).
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_set_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags)
+ * 	Description
+ * 		Populate tunnel metadata for packet associated to *skb.* The
+ * 		tunnel metadata is set to the contents of *key*, of *size*. The
+ * 		*flags* can be set to a combination of the following values:
+ *
+ * 		**BPF_F_TUNINFO_IPV6**
+ * 			Indicate that the tunnel is based on IPv6 protocol
+ * 			instead of IPv4.
+ * 		**BPF_F_ZERO_CSUM_TX**
+ * 			For IPv4 packets, add a flag to tunnel metadata
+ * 			indicating that checksum computation should be skipped
+ * 			and checksum set to zeroes.
+ * 		**BPF_F_DONT_FRAGMENT**
+ * 			Add a flag to tunnel metadata indicating that the
+ * 			packet should not be fragmented.
+ * 		**BPF_F_SEQ_NUMBER**
+ * 			Add a flag to tunnel metadata indicating that a
+ * 			sequence number should be added to tunnel header before
+ * 			sending the packet. This flag was added for GRE
+ * 			encapsulation, but might be used with other protocols
+ * 			as well in the future.
+ *
+ * 		Here is a typical usage on the transmit path:
+ *
+ * 		::
+ *
+ * 			struct bpf_tunnel_key key;
+ * 			     populate key ...
+ * 			bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0);
+ * 			bpf_clone_redirect(skb, vxlan_dev_ifindex, 0);
+ *
+ * 		See also the description of the **bpf_skb_get_tunnel_key**\ ()
+ * 		helper for additional information.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_perf_event_read(struct bpf_map *map, u64 flags)
+ * 	Description
+ * 		Read the value of a perf event counter. This helper relies on a
+ * 		*map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of
+ * 		the perf event counter is selected when *map* is updated with
+ * 		perf event file descriptors. The *map* is an array whose size
+ * 		is the number of available CPUs, and each cell contains a value
+ * 		relative to one CPU. The value to retrieve is indicated by
+ * 		*flags*, that contains the index of the CPU to look up, masked
+ * 		with **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
+ * 		**BPF_F_CURRENT_CPU** to indicate that the value for the
+ * 		current CPU should be retrieved.
+ *
+ * 		Note that before Linux 4.13, only hardware perf event can be
+ * 		retrieved.
+ *
+ * 		Also, be aware that the newer helper
+ * 		**bpf_perf_event_read_value**\ () is recommended over
+ * 		**bpf_perf_event_read**\ () in general. The latter has some ABI
+ * 		quirks where error and counter value are used as a return code
+ * 		(which is wrong to do since ranges may overlap). This issue is
+ * 		fixed with **bpf_perf_event_read_value**\ (), which at the same
+ * 		time provides more features over the **bpf_perf_event_read**\
+ * 		() interface. Please refer to the description of
+ * 		**bpf_perf_event_read_value**\ () for details.
+ * 	Return
+ * 		The value of the perf event counter read from the map, or a
+ * 		negative error code in case of failure.
+ *
+ * int bpf_redirect(u32 ifindex, u64 flags)
+ * 	Description
+ * 		Redirect the packet to another net device of index *ifindex*.
+ * 		This helper is somewhat similar to **bpf_clone_redirect**\
+ * 		(), except that the packet is not cloned, which provides
+ * 		increased performance.
+ *
+ * 		Except for XDP, both ingress and egress interfaces can be used
+ * 		for redirection. The **BPF_F_INGRESS** value in *flags* is used
+ * 		to make the distinction (ingress path is selected if the flag
+ * 		is present, egress path otherwise). Currently, XDP only
+ * 		supports redirection to the egress interface, and accepts no
+ * 		flag at all.
+ *
+ * 		The same effect can be attained with the more generic
+ * 		**bpf_redirect_map**\ (), which requires specific maps to be
+ * 		used but offers better performance.
+ * 	Return
+ * 		For XDP, the helper returns **XDP_REDIRECT** on success or
+ * 		**XDP_ABORTED** on error. For other program types, the values
+ * 		are **TC_ACT_REDIRECT** on success or **TC_ACT_SHOT** on
+ * 		error.
+ *
+ * u32 bpf_get_route_realm(struct sk_buff *skb)
+ * 	Description
+ * 		Retrieve the realm or the route, that is to say the
+ * 		**tclassid** field of the destination for the *skb*. The
+ * 		indentifier retrieved is a user-provided tag, similar to the
+ * 		one used with the net_cls cgroup (see description for
+ * 		**bpf_get_cgroup_classid**\ () helper), but here this tag is
+ * 		held by a route (a destination entry), not by a task.
+ *
+ * 		Retrieving this identifier works with the clsact TC egress hook
+ * 		(see also **tc-bpf(8)**), or alternatively on conventional
+ * 		classful egress qdiscs, but not on TC ingress path. In case of
+ * 		clsact TC egress hook, this has the advantage that, internally,
+ * 		the destination entry has not been dropped yet in the transmit
+ * 		path. Therefore, the destination entry does not need to be
+ * 		artificially held via **netif_keep_dst**\ () for a classful
+ * 		qdisc until the *skb* is freed.
+ *
+ * 		This helper is available only if the kernel was compiled with
+ * 		**CONFIG_IP_ROUTE_CLASSID** configuration option.
+ * 	Return
+ * 		The realm of the route for the packet associated to *skb*, or 0
+ * 		if none was found.
+ *
+ * int bpf_perf_event_output(struct pt_reg *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
+ * 	Description
+ * 		Write raw *data* blob into a special BPF perf event held by
+ * 		*map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
+ * 		event must have the following attributes: **PERF_SAMPLE_RAW**
+ * 		as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
+ * 		**PERF_COUNT_SW_BPF_OUTPUT** as **config**.
+ *
+ * 		The *flags* are used to indicate the index in *map* for which
+ * 		the value must be put, masked with **BPF_F_INDEX_MASK**.
+ * 		Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
+ * 		to indicate that the index of the current CPU core should be
+ * 		used.
+ *
+ * 		The value to write, of *size*, is passed through eBPF stack and
+ * 		pointed by *data*.
+ *
+ * 		The context of the program *ctx* needs also be passed to the
+ * 		helper.
+ *
+ * 		On user space, a program willing to read the values needs to
+ * 		call **perf_event_open**\ () on the perf event (either for
+ * 		one or for all CPUs) and to store the file descriptor into the
+ * 		*map*. This must be done before the eBPF program can send data
+ * 		into it. An example is available in file
+ * 		*samples/bpf/trace_output_user.c* in the Linux kernel source
+ * 		tree (the eBPF program counterpart is in
+ * 		*samples/bpf/trace_output_kern.c*).
+ *
+ * 		**bpf_perf_event_output**\ () achieves better performance
+ * 		than **bpf_trace_printk**\ () for sharing data with user
+ * 		space, and is much better suitable for streaming data from eBPF
+ * 		programs.
+ *
+ * 		Note that this helper is not restricted to tracing use cases
+ * 		and can be used with programs attached to TC or XDP as well,
+ * 		where it allows for passing data to user space listeners. Data
+ * 		can be:
+ *
+ * 		* Only custom structs,
+ * 		* Only the packet payload, or
+ * 		* A combination of both.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_load_bytes(const struct sk_buff *skb, u32 offset, void *to, u32 len)
+ * 	Description
+ * 		This helper was provided as an easy way to load data from a
+ * 		packet. It can be used to load *len* bytes from *offset* from
+ * 		the packet associated to *skb*, into the buffer pointed by
+ * 		*to*.
+ *
+ * 		Since Linux 4.7, usage of this helper has mostly been replaced
+ * 		by "direct packet access", enabling packet data to be
+ * 		manipulated with *skb*\ **->data** and *skb*\ **->data_end**
+ * 		pointing respectively to the first byte of packet data and to
+ * 		the byte after the last byte of packet data. However, it
+ * 		remains useful if one wishes to read large quantities of data
+ * 		at once from a packet into the eBPF stack.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_get_stackid(struct pt_reg *ctx, struct bpf_map *map, u64 flags)
+ * 	Description
+ * 		Walk a user or a kernel stack and return its id. To achieve
+ * 		this, the helper needs *ctx*, which is a pointer to the context
+ * 		on which the tracing program is executed, and a pointer to a
+ * 		*map* of type **BPF_MAP_TYPE_STACK_TRACE**.
+ *
+ * 		The last argument, *flags*, holds the number of stack frames to
+ * 		skip (from 0 to 255), masked with
+ * 		**BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
+ * 		a combination of the following flags:
+ *
+ * 		**BPF_F_USER_STACK**
+ * 			Collect a user space stack instead of a kernel stack.
+ * 		**BPF_F_FAST_STACK_CMP**
+ * 			Compare stacks by hash only.
+ * 		**BPF_F_REUSE_STACKID**
+ * 			If two different stacks hash into the same *stackid*,
+ * 			discard the old one.
+ *
+ * 		The stack id retrieved is a 32 bit long integer handle which
+ * 		can be further combined with other data (including other stack
+ * 		ids) and used as a key into maps. This can be useful for
+ * 		generating a variety of graphs (such as flame graphs or off-cpu
+ * 		graphs).
+ *
+ * 		For walking a stack, this helper is an improvement over
+ * 		**bpf_probe_read**\ (), which can be used with unrolled loops
+ * 		but is not efficient and consumes a lot of eBPF instructions.
+ * 		Instead, **bpf_get_stackid**\ () can collect up to
+ * 		**PERF_MAX_STACK_DEPTH** both kernel and user frames. Note that
+ * 		this limit can be controlled with the **sysctl** program, and
+ * 		that it should be manually increased in order to profile long
+ * 		user stacks (such as stacks for Java programs). To do so, use:
+ *
+ * 		::
+ *
+ * 			# sysctl kernel.perf_event_max_stack=<new value>
+ * 	Return
+ * 		The positive or null stack id on success, or a negative error
+ * 		in case of failure.
+ *
+ * s64 bpf_csum_diff(__be32 *from, u32 from_size, __be32 *to, u32 to_size, __wsum seed)
+ * 	Description
+ * 		Compute a checksum difference, from the raw buffer pointed by
+ * 		*from*, of length *from_size* (that must be a multiple of 4),
+ * 		towards the raw buffer pointed by *to*, of size *to_size*
+ * 		(same remark). An optional *seed* can be added to the value
+ * 		(this can be cascaded, the seed may come from a previous call
+ * 		to the helper).
+ *
+ * 		This is flexible enough to be used in several ways:
+ *
+ * 		* With *from_size* == 0, *to_size* > 0 and *seed* set to
+ * 		  checksum, it can be used when pushing new data.
+ * 		* With *from_size* > 0, *to_size* == 0 and *seed* set to
+ * 		  checksum, it can be used when removing data from a packet.
+ * 		* With *from_size* > 0, *to_size* > 0 and *seed* set to 0, it
+ * 		  can be used to compute a diff. Note that *from_size* and
+ * 		  *to_size* do not need to be equal.
+ *
+ * 		This helper can be used in combination with
+ * 		**bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ (), to
+ * 		which one can feed in the difference computed with
+ * 		**bpf_csum_diff**\ ().
+ * 	Return
+ * 		The checksum result, or a negative error code in case of
+ * 		failure.
+ *
+ * int bpf_skb_get_tunnel_opt(struct sk_buff *skb, u8 *opt, u32 size)
+ * 	Description
+ * 		Retrieve tunnel options metadata for the packet associated to
+ * 		*skb*, and store the raw tunnel option data to the buffer *opt*
+ * 		of *size*.
+ *
+ * 		This helper can be used with encapsulation devices that can
+ * 		operate in "collect metadata" mode (please refer to the related
+ * 		note in the description of **bpf_skb_get_tunnel_key**\ () for
+ * 		more details). A particular example where this can be used is
+ * 		in combination with the Geneve encapsulation protocol, where it
+ * 		allows for pushing (with **bpf_skb_get_tunnel_opt**\ () helper)
+ * 		and retrieving arbitrary TLVs (Type-Length-Value headers) from
+ * 		the eBPF program. This allows for full customization of these
+ * 		headers.
+ * 	Return
+ * 		The size of the option data retrieved.
+ *
+ * int bpf_skb_set_tunnel_opt(struct sk_buff *skb, u8 *opt, u32 size)
+ * 	Description
+ * 		Set tunnel options metadata for the packet associated to *skb*
+ * 		to the option data contained in the raw buffer *opt* of *size*.
+ *
+ * 		See also the description of the **bpf_skb_get_tunnel_opt**\ ()
+ * 		helper for additional information.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_change_proto(struct sk_buff *skb, __be16 proto, u64 flags)
+ * 	Description
+ * 		Change the protocol of the *skb* to *proto*. Currently
+ * 		supported are transition from IPv4 to IPv6, and from IPv6 to
+ * 		IPv4. The helper takes care of the groundwork for the
+ * 		transition, including resizing the socket buffer. The eBPF
+ * 		program is expected to fill the new headers, if any, via
+ * 		**skb_store_bytes**\ () and to recompute the checksums with
+ * 		**bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\
+ * 		(). The main case for this helper is to perform NAT64
+ * 		operations out of an eBPF program.
+ *
+ * 		Internally, the GSO type is marked as dodgy so that headers are
+ * 		checked and segments are recalculated by the GSO/GRO engine.
+ * 		The size for GSO target is adapted as well.
+ *
+ * 		All values for *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_change_type(struct sk_buff *skb, u32 type)
+ * 	Description
+ * 		Change the packet type for the packet associated to *skb*. This
+ * 		comes down to setting *skb*\ **->pkt_type** to *type*, except
+ * 		the eBPF program does not have a write access to *skb*\
+ * 		**->pkt_type** beside this helper. Using a helper here allows
+ * 		for graceful handling of errors.
+ *
+ * 		The major use case is to change incoming *skb*s to
+ * 		**PACKET_HOST** in a programmatic way instead of having to
+ * 		recirculate via **redirect**\ (..., **BPF_F_INGRESS**), for
+ * 		example.
+ *
+ * 		Note that *type* only allows certain values. At this time, they
+ * 		are:
+ *
+ * 		**PACKET_HOST**
+ * 			Packet is for us.
+ * 		**PACKET_BROADCAST**
+ * 			Send packet to all.
+ * 		**PACKET_MULTICAST**
+ * 			Send packet to group.
+ * 		**PACKET_OTHERHOST**
+ * 			Send packet to someone else.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_under_cgroup(struct sk_buff *skb, struct bpf_map *map, u32 index)
+ * 	Description
+ * 		Check whether *skb* is a descendant of the cgroup2 held by
+ * 		*map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
+ * 	Return
+ * 		The return value depends on the result of the test, and can be:
+ *
+ * 		* 0, if the *skb* failed the cgroup2 descendant test.
+ * 		* 1, if the *skb* succeeded the cgroup2 descendant test.
+ * 		* A negative error code, if an error occurred.
+ *
+ * u32 bpf_get_hash_recalc(struct sk_buff *skb)
+ * 	Description
+ * 		Retrieve the hash of the packet, *skb*\ **->hash**. If it is
+ * 		not set, in particular if the hash was cleared due to mangling,
+ * 		recompute this hash. Later accesses to the hash can be done
+ * 		directly with *skb*\ **->hash**.
+ *
+ * 		Calling **bpf_set_hash_invalid**\ (), changing a packet
+ * 		prototype with **bpf_skb_change_proto**\ (), or calling
+ * 		**bpf_skb_store_bytes**\ () with the
+ * 		**BPF_F_INVALIDATE_HASH** are actions susceptible to clear
+ * 		the hash and to trigger a new computation for the next call to
+ * 		**bpf_get_hash_recalc**\ ().
+ * 	Return
+ * 		The 32-bit hash.
+ *
+ * u64 bpf_get_current_task(void)
+ * 	Return
+ * 		A pointer to the current task struct.
+ *
+ * int bpf_probe_write_user(void *dst, const void *src, u32 len)
+ * 	Description
+ * 		Attempt in a safe way to write *len* bytes from the buffer
+ * 		*src* to *dst* in memory. It only works for threads that are in
+ * 		user context, and *dst* must be a valid user space address.
+ *
+ * 		This helper should not be used to implement any kind of
+ * 		security mechanism because of TOC-TOU attacks, but rather to
+ * 		debug, divert, and manipulate execution of semi-cooperative
+ * 		processes.
+ *
+ * 		Keep in mind that this feature is meant for experiments, and it
+ * 		has a risk of crashing the system and running programs.
+ * 		Therefore, when an eBPF program using this helper is attached,
+ * 		a warning including PID and process name is printed to kernel
+ * 		logs.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_current_task_under_cgroup(struct bpf_map *map, u32 index)
+ * 	Description
+ * 		Check whether the probe is being run is the context of a given
+ * 		subset of the cgroup2 hierarchy. The cgroup2 to test is held by
+ * 		*map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
+ * 	Return
+ * 		The return value depends on the result of the test, and can be:
+ *
+ * 		* 0, if the *skb* task belongs to the cgroup2.
+ * 		* 1, if the *skb* task does not belong to the cgroup2.
+ * 		* A negative error code, if an error occurred.
+ *
+ * int bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags)
+ * 	Description
+ * 		Resize (trim or grow) the packet associated to *skb* to the
+ * 		new *len*. The *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ *
+ * 		The basic idea is that the helper performs the needed work to
+ * 		change the size of the packet, then the eBPF program rewrites
+ * 		the rest via helpers like **bpf_skb_store_bytes**\ (),
+ * 		**bpf_l3_csum_replace**\ (), **bpf_l3_csum_replace**\ ()
+ * 		and others. This helper is a slow path utility intended for
+ * 		replies with control messages. And because it is targeted for
+ * 		slow path, the helper itself can afford to be slow: it
+ * 		implicitly linearizes, unclones and drops offloads from the
+ * 		*skb*.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_pull_data(struct sk_buff *skb, u32 len)
+ * 	Description
+ * 		Pull in non-linear data in case the *skb* is non-linear and not
+ * 		all of *len* are part of the linear section. Make *len* bytes
+ * 		from *skb* readable and writable. If a zero value is passed for
+ * 		*len*, then the whole length of the *skb* is pulled.
+ *
+ * 		This helper is only needed for reading and writing with direct
+ * 		packet access.
+ *
+ * 		For direct packet access, testing that offsets to access
+ * 		are within packet boundaries (test on *skb*\ **->data_end**) is
+ * 		susceptible to fail if offsets are invalid, or if the requested
+ * 		data is in non-linear parts of the *skb*. On failure the
+ * 		program can just bail out, or in the case of a non-linear
+ * 		buffer, use a helper to make the data available. The
+ * 		**bpf_skb_load_bytes**\ () helper is a first solution to access
+ * 		the data. Another one consists in using **bpf_skb_pull_data**
+ * 		to pull in once the non-linear parts, then retesting and
+ * 		eventually access the data.
+ *
+ * 		At the same time, this also makes sure the *skb* is uncloned,
+ * 		which is a necessary condition for direct write. As this needs
+ * 		to be an invariant for the write part only, the verifier
+ * 		detects writes and adds a prologue that is calling
+ * 		**bpf_skb_pull_data()** to effectively unclone the *skb* from
+ * 		the very beginning in case it is indeed cloned.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * s64 bpf_csum_update(struct sk_buff *skb, __wsum csum)
+ * 	Description
+ * 		Add the checksum *csum* into *skb*\ **->csum** in case the
+ * 		driver has supplied a checksum for the entire packet into that
+ * 		field. Return an error otherwise. This helper is intended to be
+ * 		used in combination with **bpf_csum_diff**\ (), in particular
+ * 		when the checksum needs to be updated after data has been
+ * 		written into the packet through direct packet access.
+ * 	Return
+ * 		The checksum on success, or a negative error code in case of
+ * 		failure.
+ *
+ * void bpf_set_hash_invalid(struct sk_buff *skb)
+ * 	Description
+ * 		Invalidate the current *skb*\ **->hash**. It can be used after
+ * 		mangling on headers through direct packet access, in order to
+ * 		indicate that the hash is outdated and to trigger a
+ * 		recalculation the next time the kernel tries to access this
+ * 		hash or when the **bpf_get_hash_recalc**\ () helper is called.
+ *
+ * int bpf_get_numa_node_id(void)
+ * 	Description
+ * 		Return the id of the current NUMA node. The primary use case
+ * 		for this helper is the selection of sockets for the local NUMA
+ * 		node, when the program is attached to sockets using the
+ * 		**SO_ATTACH_REUSEPORT_EBPF** option (see also **socket(7)**),
+ * 		but the helper is also available to other eBPF program types,
+ * 		similarly to **bpf_get_smp_processor_id**\ ().
+ * 	Return
+ * 		The id of current NUMA node.
+ *
+ * int bpf_skb_change_head(struct sk_buff *skb, u32 len, u64 flags)
+ * 	Description
+ * 		Grows headroom of packet associated to *skb* and adjusts the
+ * 		offset of the MAC header accordingly, adding *len* bytes of
+ * 		space. It automatically extends and reallocates memory as
+ * 		required.
+ *
+ * 		This helper can be used on a layer 3 *skb* to push a MAC header
+ * 		for redirection into a layer 2 device.
+ *
+ * 		All values for *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_xdp_adjust_head(struct xdp_buff *xdp_md, int delta)
+ * 	Description
+ * 		Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that
+ * 		it is possible to use a negative value for *delta*. This helper
+ * 		can be used to prepare the packet for pushing or popping
+ * 		headers.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_probe_read_str(void *dst, int size, const void *unsafe_ptr)
+ * 	Description
+ * 		Copy a NUL terminated string from an unsafe address
+ * 		*unsafe_ptr* to *dst*. The *size* should include the
+ * 		terminating NUL byte. In case the string length is smaller than
+ * 		*size*, the target is not padded with further NUL bytes. If the
+ * 		string length is larger than *size*, just *size*-1 bytes are
+ * 		copied and the last byte is set to NUL.
+ *
+ * 		On success, the length of the copied string is returned. This
+ * 		makes this helper useful in tracing programs for reading
+ * 		strings, and more importantly to get its length at runtime. See
+ * 		the following snippet:
+ *
+ * 		::
+ *
+ * 			SEC("kprobe/sys_open")
+ * 			void bpf_sys_open(struct pt_regs *ctx)
+ * 			{
+ * 			        char buf[PATHLEN]; // PATHLEN is defined to 256
+ * 			        int res = bpf_probe_read_str(buf, sizeof(buf),
+ * 				                             ctx->di);
+ *
+ * 				// Consume buf, for example push it to
+ * 				// userspace via bpf_perf_event_output(); we
+ * 				// can use res (the string length) as event
+ * 				// size, after checking its boundaries.
+ * 			}
+ *
+ * 		In comparison, using **bpf_probe_read()** helper here instead
+ * 		to read the string would require to estimate the length at
+ * 		compile time, and would often result in copying more memory
+ * 		than necessary.
+ *
+ * 		Another useful use case is when parsing individual process
+ * 		arguments or individual environment variables navigating
+ * 		*current*\ **->mm->arg_start** and *current*\
+ * 		**->mm->env_start**: using this helper and the return value,
+ * 		one can quickly iterate at the right offset of the memory area.
+ * 	Return
+ * 		On success, the strictly positive length of the string,
+ * 		including the trailing NUL character. On error, a negative
+ * 		value.
+ *
+ * u64 bpf_get_socket_cookie(struct sk_buff *skb)
+ * 	Description
+ * 		If the **struct sk_buff** pointed by *skb* has a known socket,
+ * 		retrieve the cookie (generated by the kernel) of this socket.
+ * 		If no cookie has been set yet, generate a new cookie. Once
+ * 		generated, the socket cookie remains stable for the life of the
+ * 		socket. This helper can be useful for monitoring per socket
+ * 		networking traffic statistics as it provides a unique socket
+ * 		identifier per namespace.
+ * 	Return
+ * 		A 8-byte long non-decreasing number on success, or 0 if the
+ * 		socket field is missing inside *skb*.
+ *
+ * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
+ * 	Description
+ * 		Equivalent to bpf_get_socket_cookie() helper that accepts
+ * 		*skb*, but gets socket from **struct bpf_sock_addr** context.
+ * 	Return
+ * 		A 8-byte long non-decreasing number.
+ *
+ * u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx)
+ * 	Description
+ * 		Equivalent to bpf_get_socket_cookie() helper that accepts
+ * 		*skb*, but gets socket from **struct bpf_sock_ops** context.
+ * 	Return
+ * 		A 8-byte long non-decreasing number.
+ *
+ * u32 bpf_get_socket_uid(struct sk_buff *skb)
+ * 	Return
+ * 		The owner UID of the socket associated to *skb*. If the socket
+ * 		is **NULL**, or if it is not a full socket (i.e. if it is a
+ * 		time-wait or a request socket instead), **overflowuid** value
+ * 		is returned (note that **overflowuid** might also be the actual
+ * 		UID value for the socket).
+ *
+ * u32 bpf_set_hash(struct sk_buff *skb, u32 hash)
+ * 	Description
+ * 		Set the full hash for *skb* (set the field *skb*\ **->hash**)
+ * 		to value *hash*.
+ * 	Return
+ * 		0
+ *
+ * int bpf_setsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, char *optval, int optlen)
+ * 	Description
+ * 		Emulate a call to **setsockopt()** on the socket associated to
+ * 		*bpf_socket*, which must be a full socket. The *level* at
+ * 		which the option resides and the name *optname* of the option
+ * 		must be specified, see **setsockopt(2)** for more information.
+ * 		The option value of length *optlen* is pointed by *optval*.
+ *
+ * 		This helper actually implements a subset of **setsockopt()**.
+ * 		It supports the following *level*\ s:
+ *
+ * 		* **SOL_SOCKET**, which supports the following *optname*\ s:
+ * 		  **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,
+ * 		  **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**.
+ * 		* **IPPROTO_TCP**, which supports the following *optname*\ s:
+ * 		  **TCP_CONGESTION**, **TCP_BPF_IW**,
+ * 		  **TCP_BPF_SNDCWND_CLAMP**.
+ * 		* **IPPROTO_IP**, which supports *optname* **IP_TOS**.
+ * 		* **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_adjust_room(struct sk_buff *skb, s32 len_diff, u32 mode, u64 flags)
+ * 	Description
+ * 		Grow or shrink the room for data in the packet associated to
+ * 		*skb* by *len_diff*, and according to the selected *mode*.
+ *
+ *		There are two supported modes at this time:
+ *
+ *		* **BPF_ADJ_ROOM_MAC**: Adjust room at the mac layer
+ *		  (room space is added or removed below the layer 2 header).
+ *
+ * 		* **BPF_ADJ_ROOM_NET**: Adjust room at the network layer
+ * 		  (room space is added or removed below the layer 3 header).
+ *
+ *		The following flags are supported at this time:
+ *
+ *		* **BPF_F_ADJ_ROOM_FIXED_GSO**: Do not adjust gso_size.
+ *		  Adjusting mss in this way is not allowed for datagrams.
+ *
+ *		* **BPF_F_ADJ_ROOM_ENCAP_L3_IPV4 **:
+ *		* **BPF_F_ADJ_ROOM_ENCAP_L3_IPV6 **:
+ *		  Any new space is reserved to hold a tunnel header.
+ *		  Configure skb offsets and other fields accordingly.
+ *
+ *		* **BPF_F_ADJ_ROOM_ENCAP_L4_GRE **:
+ *		* **BPF_F_ADJ_ROOM_ENCAP_L4_UDP **:
+ *		  Use with ENCAP_L3 flags to further specify the tunnel type.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_redirect_map(struct bpf_map *map, u32 key, u64 flags)
+ * 	Description
+ * 		Redirect the packet to the endpoint referenced by *map* at
+ * 		index *key*. Depending on its type, this *map* can contain
+ * 		references to net devices (for forwarding packets through other
+ * 		ports), or to CPUs (for redirecting XDP frames to another CPU;
+ * 		but this is only implemented for native XDP (with driver
+ * 		support) as of this writing).
+ *
+ * 		All values for *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ *
+ * 		When used to redirect packets to net devices, this helper
+ * 		provides a high performance increase over **bpf_redirect**\ ().
+ * 		This is due to various implementation details of the underlying
+ * 		mechanisms, one of which is the fact that **bpf_redirect_map**\
+ * 		() tries to send packet as a "bulk" to the device.
+ * 	Return
+ * 		**XDP_REDIRECT** on success, or **XDP_ABORTED** on error.
+ *
+ * int bpf_sk_redirect_map(struct bpf_map *map, u32 key, u64 flags)
+ * 	Description
+ * 		Redirect the packet to the socket referenced by *map* (of type
+ * 		**BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
+ * 		egress interfaces can be used for redirection. The
+ * 		**BPF_F_INGRESS** value in *flags* is used to make the
+ * 		distinction (ingress path is selected if the flag is present,
+ * 		egress path otherwise). This is the only flag supported for now.
+ * 	Return
+ * 		**SK_PASS** on success, or **SK_DROP** on error.
+ *
+ * int bpf_sock_map_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags)
+ * 	Description
+ * 		Add an entry to, or update a *map* referencing sockets. The
+ * 		*skops* is used as a new value for the entry associated to
+ * 		*key*. *flags* is one of:
+ *
+ * 		**BPF_NOEXIST**
+ * 			The entry for *key* must not exist in the map.
+ * 		**BPF_EXIST**
+ * 			The entry for *key* must already exist in the map.
+ * 		**BPF_ANY**
+ * 			No condition on the existence of the entry for *key*.
+ *
+ * 		If the *map* has eBPF programs (parser and verdict), those will
+ * 		be inherited by the socket being added. If the socket is
+ * 		already attached to eBPF programs, this results in an error.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_xdp_adjust_meta(struct xdp_buff *xdp_md, int delta)
+ * 	Description
+ * 		Adjust the address pointed by *xdp_md*\ **->data_meta** by
+ * 		*delta* (which can be positive or negative). Note that this
+ * 		operation modifies the address stored in *xdp_md*\ **->data**,
+ * 		so the latter must be loaded only after the helper has been
+ * 		called.
+ *
+ * 		The use of *xdp_md*\ **->data_meta** is optional and programs
+ * 		are not required to use it. The rationale is that when the
+ * 		packet is processed with XDP (e.g. as DoS filter), it is
+ * 		possible to push further meta data along with it before passing
+ * 		to the stack, and to give the guarantee that an ingress eBPF
+ * 		program attached as a TC classifier on the same device can pick
+ * 		this up for further post-processing. Since TC works with socket
+ * 		buffers, it remains possible to set from XDP the **mark** or
+ * 		**priority** pointers, or other pointers for the socket buffer.
+ * 		Having this scratch space generic and programmable allows for
+ * 		more flexibility as the user is free to store whatever meta
+ * 		data they need.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_perf_event_read_value(struct bpf_map *map, u64 flags, struct bpf_perf_event_value *buf, u32 buf_size)
+ * 	Description
+ * 		Read the value of a perf event counter, and store it into *buf*
+ * 		of size *buf_size*. This helper relies on a *map* of type
+ * 		**BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of the perf event
+ * 		counter is selected when *map* is updated with perf event file
+ * 		descriptors. The *map* is an array whose size is the number of
+ * 		available CPUs, and each cell contains a value relative to one
+ * 		CPU. The value to retrieve is indicated by *flags*, that
+ * 		contains the index of the CPU to look up, masked with
+ * 		**BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
+ * 		**BPF_F_CURRENT_CPU** to indicate that the value for the
+ * 		current CPU should be retrieved.
+ *
+ * 		This helper behaves in a way close to
+ * 		**bpf_perf_event_read**\ () helper, save that instead of
+ * 		just returning the value observed, it fills the *buf*
+ * 		structure. This allows for additional data to be retrieved: in
+ * 		particular, the enabled and running times (in *buf*\
+ * 		**->enabled** and *buf*\ **->running**, respectively) are
+ * 		copied. In general, **bpf_perf_event_read_value**\ () is
+ * 		recommended over **bpf_perf_event_read**\ (), which has some
+ * 		ABI issues and provides fewer functionalities.
+ *
+ * 		These values are interesting, because hardware PMU (Performance
+ * 		Monitoring Unit) counters are limited resources. When there are
+ * 		more PMU based perf events opened than available counters,
+ * 		kernel will multiplex these events so each event gets certain
+ * 		percentage (but not all) of the PMU time. In case that
+ * 		multiplexing happens, the number of samples or counter value
+ * 		will not reflect the case compared to when no multiplexing
+ * 		occurs. This makes comparison between different runs difficult.
+ * 		Typically, the counter value should be normalized before
+ * 		comparing to other experiments. The usual normalization is done
+ * 		as follows.
+ *
+ * 		::
+ *
+ * 			normalized_counter = counter * t_enabled / t_running
+ *
+ * 		Where t_enabled is the time enabled for event and t_running is
+ * 		the time running for event since last normalization. The
+ * 		enabled and running times are accumulated since the perf event
+ * 		open. To achieve scaling factor between two invocations of an
+ * 		eBPF program, users can can use CPU id as the key (which is
+ * 		typical for perf array usage model) to remember the previous
+ * 		value and do the calculation inside the eBPF program.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_perf_prog_read_value(struct bpf_perf_event_data *ctx, struct bpf_perf_event_value *buf, u32 buf_size)
+ * 	Description
+ * 		For en eBPF program attached to a perf event, retrieve the
+ * 		value of the event counter associated to *ctx* and store it in
+ * 		the structure pointed by *buf* and of size *buf_size*. Enabled
+ * 		and running times are also stored in the structure (see
+ * 		description of helper **bpf_perf_event_read_value**\ () for
+ * 		more details).
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_getsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, char *optval, int optlen)
+ * 	Description
+ * 		Emulate a call to **getsockopt()** on the socket associated to
+ * 		*bpf_socket*, which must be a full socket. The *level* at
+ * 		which the option resides and the name *optname* of the option
+ * 		must be specified, see **getsockopt(2)** for more information.
+ * 		The retrieved value is stored in the structure pointed by
+ * 		*opval* and of length *optlen*.
+ *
+ * 		This helper actually implements a subset of **getsockopt()**.
+ * 		It supports the following *level*\ s:
+ *
+ * 		* **IPPROTO_TCP**, which supports *optname*
+ * 		  **TCP_CONGESTION**.
+ * 		* **IPPROTO_IP**, which supports *optname* **IP_TOS**.
+ * 		* **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_override_return(struct pt_reg *regs, u64 rc)
+ * 	Description
+ * 		Used for error injection, this helper uses kprobes to override
+ * 		the return value of the probed function, and to set it to *rc*.
+ * 		The first argument is the context *regs* on which the kprobe
+ * 		works.
+ *
+ * 		This helper works by setting setting the PC (program counter)
+ * 		to an override function which is run in place of the original
+ * 		probed function. This means the probed function is not run at
+ * 		all. The replacement function just returns with the required
+ * 		value.
+ *
+ * 		This helper has security implications, and thus is subject to
+ * 		restrictions. It is only available if the kernel was compiled
+ * 		with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration
+ * 		option, and in this case it only works on functions tagged with
+ * 		**ALLOW_ERROR_INJECTION** in the kernel code.
+ *
+ * 		Also, the helper is only available for the architectures having
+ * 		the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing,
+ * 		x86 architecture is the only one to support this feature.
+ * 	Return
+ * 		0
+ *
+ * int bpf_sock_ops_cb_flags_set(struct bpf_sock_ops *bpf_sock, int argval)
+ * 	Description
+ * 		Attempt to set the value of the **bpf_sock_ops_cb_flags** field
+ * 		for the full TCP socket associated to *bpf_sock_ops* to
+ * 		*argval*.
+ *
+ * 		The primary use of this field is to determine if there should
+ * 		be calls to eBPF programs of type
+ * 		**BPF_PROG_TYPE_SOCK_OPS** at various points in the TCP
+ * 		code. A program of the same type can change its value, per
+ * 		connection and as necessary, when the connection is
+ * 		established. This field is directly accessible for reading, but
+ * 		this helper must be used for updates in order to return an
+ * 		error if an eBPF program tries to set a callback that is not
+ * 		supported in the current kernel.
+ *
+ * 		The supported callback values that *argval* can combine are:
+ *
+ * 		* **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out)
+ * 		* **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission)
+ * 		* **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change)
+ *
+ * 		Here are some examples of where one could call such eBPF
+ * 		program:
+ *
+ * 		* When RTO fires.
+ * 		* When a packet is retransmitted.
+ * 		* When the connection terminates.
+ * 		* When a packet is sent.
+ * 		* When a packet is received.
+ * 	Return
+ * 		Code **-EINVAL** if the socket is not a full TCP socket;
+ * 		otherwise, a positive number containing the bits that could not
+ * 		be set is returned (which comes down to 0 if all bits were set
+ * 		as required).
+ *
+ * int bpf_msg_redirect_map(struct sk_msg_buff *msg, struct bpf_map *map, u32 key, u64 flags)
+ * 	Description
+ * 		This helper is used in programs implementing policies at the
+ * 		socket level. If the message *msg* is allowed to pass (i.e. if
+ * 		the verdict eBPF program returns **SK_PASS**), redirect it to
+ * 		the socket referenced by *map* (of type
+ * 		**BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
+ * 		egress interfaces can be used for redirection. The
+ * 		**BPF_F_INGRESS** value in *flags* is used to make the
+ * 		distinction (ingress path is selected if the flag is present,
+ * 		egress path otherwise). This is the only flag supported for now.
+ * 	Return
+ * 		**SK_PASS** on success, or **SK_DROP** on error.
+ *
+ * int bpf_msg_apply_bytes(struct sk_msg_buff *msg, u32 bytes)
+ * 	Description
+ * 		For socket policies, apply the verdict of the eBPF program to
+ * 		the next *bytes* (number of bytes) of message *msg*.
+ *
+ * 		For example, this helper can be used in the following cases:
+ *
+ * 		* A single **sendmsg**\ () or **sendfile**\ () system call
+ * 		  contains multiple logical messages that the eBPF program is
+ * 		  supposed to read and for which it should apply a verdict.
+ * 		* An eBPF program only cares to read the first *bytes* of a
+ * 		  *msg*. If the message has a large payload, then setting up
+ * 		  and calling the eBPF program repeatedly for all bytes, even
+ * 		  though the verdict is already known, would create unnecessary
+ * 		  overhead.
+ *
+ * 		When called from within an eBPF program, the helper sets a
+ * 		counter internal to the BPF infrastructure, that is used to
+ * 		apply the last verdict to the next *bytes*. If *bytes* is
+ * 		smaller than the current data being processed from a
+ * 		**sendmsg**\ () or **sendfile**\ () system call, the first
+ * 		*bytes* will be sent and the eBPF program will be re-run with
+ * 		the pointer for start of data pointing to byte number *bytes*
+ * 		**+ 1**. If *bytes* is larger than the current data being
+ * 		processed, then the eBPF verdict will be applied to multiple
+ * 		**sendmsg**\ () or **sendfile**\ () calls until *bytes* are
+ * 		consumed.
+ *
+ * 		Note that if a socket closes with the internal counter holding
+ * 		a non-zero value, this is not a problem because data is not
+ * 		being buffered for *bytes* and is sent as it is received.
+ * 	Return
+ * 		0
+ *
+ * int bpf_msg_cork_bytes(struct sk_msg_buff *msg, u32 bytes)
+ * 	Description
+ * 		For socket policies, prevent the execution of the verdict eBPF
+ * 		program for message *msg* until *bytes* (byte number) have been
+ * 		accumulated.
+ *
+ * 		This can be used when one needs a specific number of bytes
+ * 		before a verdict can be assigned, even if the data spans
+ * 		multiple **sendmsg**\ () or **sendfile**\ () calls. The extreme
+ * 		case would be a user calling **sendmsg**\ () repeatedly with
+ * 		1-byte long message segments. Obviously, this is bad for
+ * 		performance, but it is still valid. If the eBPF program needs
+ * 		*bytes* bytes to validate a header, this helper can be used to
+ * 		prevent the eBPF program to be called again until *bytes* have
+ * 		been accumulated.
+ * 	Return
+ * 		0
+ *
+ * int bpf_msg_pull_data(struct sk_msg_buff *msg, u32 start, u32 end, u64 flags)
+ * 	Description
+ * 		For socket policies, pull in non-linear data from user space
+ * 		for *msg* and set pointers *msg*\ **->data** and *msg*\
+ * 		**->data_end** to *start* and *end* bytes offsets into *msg*,
+ * 		respectively.
+ *
+ * 		If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
+ * 		*msg* it can only parse data that the (**data**, **data_end**)
+ * 		pointers have already consumed. For **sendmsg**\ () hooks this
+ * 		is likely the first scatterlist element. But for calls relying
+ * 		on the **sendpage** handler (e.g. **sendfile**\ ()) this will
+ * 		be the range (**0**, **0**) because the data is shared with
+ * 		user space and by default the objective is to avoid allowing
+ * 		user space to modify data while (or after) eBPF verdict is
+ * 		being decided. This helper can be used to pull in data and to
+ * 		set the start and end pointer to given values. Data will be
+ * 		copied if necessary (i.e. if data was not linear and if start
+ * 		and end pointers do not point to the same chunk).
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *
+ * 		All values for *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_bind(struct bpf_sock_addr *ctx, struct sockaddr *addr, int addr_len)
+ * 	Description
+ * 		Bind the socket associated to *ctx* to the address pointed by
+ * 		*addr*, of length *addr_len*. This allows for making outgoing
+ * 		connection from the desired IP address, which can be useful for
+ * 		example when all processes inside a cgroup should use one
+ * 		single IP address on a host that has multiple IP configured.
+ *
+ * 		This helper works for IPv4 and IPv6, TCP and UDP sockets. The
+ * 		domain (*addr*\ **->sa_family**) must be **AF_INET** (or
+ * 		**AF_INET6**). Looking for a free port to bind to can be
+ * 		expensive, therefore binding to port is not permitted by the
+ * 		helper: *addr*\ **->sin_port** (or **sin6_port**, respectively)
+ * 		must be set to zero.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_xdp_adjust_tail(struct xdp_buff *xdp_md, int delta)
+ * 	Description
+ * 		Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is
+ * 		only possible to shrink the packet as of this writing,
+ * 		therefore *delta* must be a negative integer.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_get_xfrm_state(struct sk_buff *skb, u32 index, struct bpf_xfrm_state *xfrm_state, u32 size, u64 flags)
+ * 	Description
+ * 		Retrieve the XFRM state (IP transform framework, see also
+ * 		**ip-xfrm(8)**) at *index* in XFRM "security path" for *skb*.
+ *
+ * 		The retrieved value is stored in the **struct bpf_xfrm_state**
+ * 		pointed by *xfrm_state* and of length *size*.
+ *
+ * 		All values for *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ *
+ * 		This helper is available only if the kernel was compiled with
+ * 		**CONFIG_XFRM** configuration option.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_get_stack(struct pt_regs *regs, void *buf, u32 size, u64 flags)
+ * 	Description
+ * 		Return a user or a kernel stack in bpf program provided buffer.
+ * 		To achieve this, the helper needs *ctx*, which is a pointer
+ * 		to the context on which the tracing program is executed.
+ * 		To store the stacktrace, the bpf program provides *buf* with
+ * 		a nonnegative *size*.
+ *
+ * 		The last argument, *flags*, holds the number of stack frames to
+ * 		skip (from 0 to 255), masked with
+ * 		**BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
+ * 		the following flags:
+ *
+ * 		**BPF_F_USER_STACK**
+ * 			Collect a user space stack instead of a kernel stack.
+ * 		**BPF_F_USER_BUILD_ID**
+ * 			Collect buildid+offset instead of ips for user stack,
+ * 			only valid if **BPF_F_USER_STACK** is also specified.
+ *
+ * 		**bpf_get_stack**\ () can collect up to
+ * 		**PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
+ * 		to sufficient large buffer size. Note that
+ * 		this limit can be controlled with the **sysctl** program, and
+ * 		that it should be manually increased in order to profile long
+ * 		user stacks (such as stacks for Java programs). To do so, use:
+ *
+ * 		::
+ *
+ * 			# sysctl kernel.perf_event_max_stack=<new value>
+ * 	Return
+ * 		A non-negative value equal to or less than *size* on success,
+ * 		or a negative error in case of failure.
+ *
+ * int bpf_skb_load_bytes_relative(const struct sk_buff *skb, u32 offset, void *to, u32 len, u32 start_header)
+ * 	Description
+ * 		This helper is similar to **bpf_skb_load_bytes**\ () in that
+ * 		it provides an easy way to load *len* bytes from *offset*
+ * 		from the packet associated to *skb*, into the buffer pointed
+ * 		by *to*. The difference to **bpf_skb_load_bytes**\ () is that
+ * 		a fifth argument *start_header* exists in order to select a
+ * 		base offset to start from. *start_header* can be one of:
+ *
+ * 		**BPF_HDR_START_MAC**
+ * 			Base offset to load data from is *skb*'s mac header.
+ * 		**BPF_HDR_START_NET**
+ * 			Base offset to load data from is *skb*'s network header.
+ *
+ * 		In general, "direct packet access" is the preferred method to
+ * 		access packet data, however, this helper is in particular useful
+ * 		in socket filters where *skb*\ **->data** does not always point
+ * 		to the start of the mac header and where "direct packet access"
+ * 		is not available.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags)
+ *	Description
+ *		Do FIB lookup in kernel tables using parameters in *params*.
+ *		If lookup is successful and result shows packet is to be
+ *		forwarded, the neighbor tables are searched for the nexthop.
+ *		If successful (ie., FIB lookup shows forwarding and nexthop
+ *		is resolved), the nexthop address is returned in ipv4_dst
+ *		or ipv6_dst based on family, smac is set to mac address of
+ *		egress device, dmac is set to nexthop mac address, rt_metric
+ *		is set to metric from route (IPv4/IPv6 only), and ifindex
+ *		is set to the device index of the nexthop from the FIB lookup.
+ *
+ *		*plen* argument is the size of the passed in struct.
+ *		*flags* argument can be a combination of one or more of the
+ *		following values:
+ *
+ *		**BPF_FIB_LOOKUP_DIRECT**
+ *			Do a direct table lookup vs full lookup using FIB
+ *			rules.
+ *		**BPF_FIB_LOOKUP_OUTPUT**
+ *			Perform lookup from an egress perspective (default is
+ *			ingress).
+ *
+ *		*ctx* is either **struct xdp_md** for XDP programs or
+ *		**struct sk_buff** tc cls_act programs.
+ *	Return
+ *		* < 0 if any input argument is invalid
+ *		*   0 on success (packet is forwarded, nexthop neighbor exists)
+ *		* > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the
+ *		  packet is not forwarded or needs assist from full stack
+ *
+ * int bpf_sock_hash_update(struct bpf_sock_ops_kern *skops, struct bpf_map *map, void *key, u64 flags)
+ *	Description
+ *		Add an entry to, or update a sockhash *map* referencing sockets.
+ *		The *skops* is used as a new value for the entry associated to
+ *		*key*. *flags* is one of:
+ *
+ *		**BPF_NOEXIST**
+ *			The entry for *key* must not exist in the map.
+ *		**BPF_EXIST**
+ *			The entry for *key* must already exist in the map.
+ *		**BPF_ANY**
+ *			No condition on the existence of the entry for *key*.
+ *
+ *		If the *map* has eBPF programs (parser and verdict), those will
+ *		be inherited by the socket being added. If the socket is
+ *		already attached to eBPF programs, this results in an error.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_msg_redirect_hash(struct sk_msg_buff *msg, struct bpf_map *map, void *key, u64 flags)
+ *	Description
+ *		This helper is used in programs implementing policies at the
+ *		socket level. If the message *msg* is allowed to pass (i.e. if
+ *		the verdict eBPF program returns **SK_PASS**), redirect it to
+ *		the socket referenced by *map* (of type
+ *		**BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
+ *		egress interfaces can be used for redirection. The
+ *		**BPF_F_INGRESS** value in *flags* is used to make the
+ *		distinction (ingress path is selected if the flag is present,
+ *		egress path otherwise). This is the only flag supported for now.
+ *	Return
+ *		**SK_PASS** on success, or **SK_DROP** on error.
+ *
+ * int bpf_sk_redirect_hash(struct sk_buff *skb, struct bpf_map *map, void *key, u64 flags)
+ *	Description
+ *		This helper is used in programs implementing policies at the
+ *		skb socket level. If the sk_buff *skb* is allowed to pass (i.e.
+ *		if the verdeict eBPF program returns **SK_PASS**), redirect it
+ *		to the socket referenced by *map* (of type
+ *		**BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
+ *		egress interfaces can be used for redirection. The
+ *		**BPF_F_INGRESS** value in *flags* is used to make the
+ *		distinction (ingress path is selected if the flag is present,
+ *		egress otherwise). This is the only flag supported for now.
+ *	Return
+ *		**SK_PASS** on success, or **SK_DROP** on error.
+ *
+ * int bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len)
+ *	Description
+ *		Encapsulate the packet associated to *skb* within a Layer 3
+ *		protocol header. This header is provided in the buffer at
+ *		address *hdr*, with *len* its size in bytes. *type* indicates
+ *		the protocol of the header and can be one of:
+ *
+ *		**BPF_LWT_ENCAP_SEG6**
+ *			IPv6 encapsulation with Segment Routing Header
+ *			(**struct ipv6_sr_hdr**). *hdr* only contains the SRH,
+ *			the IPv6 header is computed by the kernel.
+ *		**BPF_LWT_ENCAP_SEG6_INLINE**
+ *			Only works if *skb* contains an IPv6 packet. Insert a
+ *			Segment Routing Header (**struct ipv6_sr_hdr**) inside
+ *			the IPv6 header.
+ *		**BPF_LWT_ENCAP_IP**
+ *			IP encapsulation (GRE/GUE/IPIP/etc). The outer header
+ *			must be IPv4 or IPv6, followed by zero or more
+ *			additional headers, up to LWT_BPF_MAX_HEADROOM total
+ *			bytes in all prepended headers. Please note that
+ *			if skb_is_gso(skb) is true, no more than two headers
+ *			can be prepended, and the inner header, if present,
+ *			should be either GRE or UDP/GUE.
+ *
+ *		BPF_LWT_ENCAP_SEG6*** types can be called by bpf programs of
+ *		type BPF_PROG_TYPE_LWT_IN; BPF_LWT_ENCAP_IP type can be called
+ *		by bpf programs of types BPF_PROG_TYPE_LWT_IN and
+ *		BPF_PROG_TYPE_LWT_XMIT.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len)
+ *	Description
+ *		Store *len* bytes from address *from* into the packet
+ *		associated to *skb*, at *offset*. Only the flags, tag and TLVs
+ *		inside the outermost IPv6 Segment Routing Header can be
+ *		modified through this helper.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta)
+ *	Description
+ *		Adjust the size allocated to TLVs in the outermost IPv6
+ *		Segment Routing Header contained in the packet associated to
+ *		*skb*, at position *offset* by *delta* bytes. Only offsets
+ *		after the segments are accepted. *delta* can be as well
+ *		positive (growing) as negative (shrinking).
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len)
+ *	Description
+ *		Apply an IPv6 Segment Routing action of type *action* to the
+ *		packet associated to *skb*. Each action takes a parameter
+ *		contained at address *param*, and of length *param_len* bytes.
+ *		*action* can be one of:
+ *
+ *		**SEG6_LOCAL_ACTION_END_X**
+ *			End.X action: Endpoint with Layer-3 cross-connect.
+ *			Type of *param*: **struct in6_addr**.
+ *		**SEG6_LOCAL_ACTION_END_T**
+ *			End.T action: Endpoint with specific IPv6 table lookup.
+ *			Type of *param*: **int**.
+ *		**SEG6_LOCAL_ACTION_END_B6**
+ *			End.B6 action: Endpoint bound to an SRv6 policy.
+ *			Type of param: **struct ipv6_sr_hdr**.
+ *		**SEG6_LOCAL_ACTION_END_B6_ENCAP**
+ *			End.B6.Encap action: Endpoint bound to an SRv6
+ *			encapsulation policy.
+ *			Type of param: **struct ipv6_sr_hdr**.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_rc_repeat(void *ctx)
+ *	Description
+ *		This helper is used in programs implementing IR decoding, to
+ *		report a successfully decoded repeat key message. This delays
+ *		the generation of a key up event for previously generated
+ *		key down event.
+ *
+ *		Some IR protocols like NEC have a special IR message for
+ *		repeating last button, for when a button is held down.
+ *
+ *		The *ctx* should point to the lirc sample as passed into
+ *		the program.
+ *
+ *		This helper is only available is the kernel was compiled with
+ *		the **CONFIG_BPF_LIRC_MODE2** configuration option set to
+ *		"**y**".
+ *	Return
+ *		0
+ *
+ * int bpf_rc_keydown(void *ctx, u32 protocol, u64 scancode, u32 toggle)
+ *	Description
+ *		This helper is used in programs implementing IR decoding, to
+ *		report a successfully decoded key press with *scancode*,
+ *		*toggle* value in the given *protocol*. The scancode will be
+ *		translated to a keycode using the rc keymap, and reported as
+ *		an input key down event. After a period a key up event is
+ *		generated. This period can be extended by calling either
+ *		**bpf_rc_keydown**\ () again with the same values, or calling
+ *		**bpf_rc_repeat**\ ().
+ *
+ *		Some protocols include a toggle bit, in case the button	was
+ *		released and pressed again between consecutive scancodes.
+ *
+ *		The *ctx* should point to the lirc sample as passed into
+ *		the program.
+ *
+ *		The *protocol* is the decoded protocol number (see
+ *		**enum rc_proto** for some predefined values).
+ *
+ *		This helper is only available is the kernel was compiled with
+ *		the **CONFIG_BPF_LIRC_MODE2** configuration option set to
+ *		"**y**".
+ *	Return
+ *		0
+ *
+ * u64 bpf_skb_cgroup_id(struct sk_buff *skb)
+ * 	Description
+ * 		Return the cgroup v2 id of the socket associated with the *skb*.
+ * 		This is roughly similar to the **bpf_get_cgroup_classid**\ ()
+ * 		helper for cgroup v1 by providing a tag resp. identifier that
+ * 		can be matched on or used for map lookups e.g. to implement
+ * 		policy. The cgroup v2 id of a given path in the hierarchy is
+ * 		exposed in user space through the f_handle API in order to get
+ * 		to the same 64-bit id.
+ *
+ * 		This helper can be used on TC egress path, but not on ingress,
+ * 		and is available only if the kernel was compiled with the
+ * 		**CONFIG_SOCK_CGROUP_DATA** configuration option.
+ * 	Return
+ * 		The id is returned or 0 in case the id could not be retrieved.
+ *
+ * u64 bpf_get_current_cgroup_id(void)
+ * 	Return
+ * 		A 64-bit integer containing the current cgroup id based
+ * 		on the cgroup within which the current task is running.
+ *
+ * void *bpf_get_local_storage(void *map, u64 flags)
+ *	Description
+ *		Get the pointer to the local storage area.
+ *		The type and the size of the local storage is defined
+ *		by the *map* argument.
+ *		The *flags* meaning is specific for each map type,
+ *		and has to be 0 for cgroup local storage.
+ *
+ *		Depending on the BPF program type, a local storage area
+ *		can be shared between multiple instances of the BPF program,
+ *		running simultaneously.
+ *
+ *		A user should care about the synchronization by himself.
+ *		For example, by using the **BPF_STX_XADD** instruction to alter
+ *		the shared data.
+ *	Return
+ *		A pointer to the local storage area.
+ *
+ * int bpf_sk_select_reuseport(struct sk_reuseport_md *reuse, struct bpf_map *map, void *key, u64 flags)
+ *	Description
+ *		Select a **SO_REUSEPORT** socket from a
+ *		**BPF_MAP_TYPE_REUSEPORT_ARRAY** *map*.
+ *		It checks the selected socket is matching the incoming
+ *		request in the socket buffer.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_skb_ancestor_cgroup_id(struct sk_buff *skb, int ancestor_level)
+ *	Description
+ *		Return id of cgroup v2 that is ancestor of cgroup associated
+ *		with the *skb* at the *ancestor_level*.  The root cgroup is at
+ *		*ancestor_level* zero and each step down the hierarchy
+ *		increments the level. If *ancestor_level* == level of cgroup
+ *		associated with *skb*, then return value will be same as that
+ *		of **bpf_skb_cgroup_id**\ ().
+ *
+ *		The helper is useful to implement policies based on cgroups
+ *		that are upper in hierarchy than immediate cgroup associated
+ *		with *skb*.
+ *
+ *		The format of returned id and helper limitations are same as in
+ *		**bpf_skb_cgroup_id**\ ().
+ *	Return
+ *		The id is returned or 0 in case the id could not be retrieved.
+ *
+ * struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
+ *	Description
+ *		Look for TCP socket matching *tuple*, optionally in a child
+ *		network namespace *netns*. The return value must be checked,
+ *		and if non-**NULL**, released via **bpf_sk_release**\ ().
+ *
+ *		The *ctx* should point to the context of the program, such as
+ *		the skb or socket (depending on the hook in use). This is used
+ *		to determine the base network namespace for the lookup.
+ *
+ *		*tuple_size* must be one of:
+ *
+ *		**sizeof**\ (*tuple*\ **->ipv4**)
+ *			Look for an IPv4 socket.
+ *		**sizeof**\ (*tuple*\ **->ipv6**)
+ *			Look for an IPv6 socket.
+ *
+ *		If the *netns* is a negative signed 32-bit integer, then the
+ *		socket lookup table in the netns associated with the *ctx* will
+ *		will be used. For the TC hooks, this is the netns of the device
+ *		in the skb. For socket hooks, this is the netns of the socket.
+ *		If *netns* is any other signed 32-bit value greater than or
+ *		equal to zero then it specifies the ID of the netns relative to
+ *		the netns associated with the *ctx*. *netns* values beyond the
+ *		range of 32-bit integers are reserved for future use.
+ *
+ *		All values for *flags* are reserved for future usage, and must
+ *		be left at zero.
+ *
+ *		This helper is available only if the kernel was compiled with
+ *		**CONFIG_NET** configuration option.
+ *	Return
+ *		Pointer to **struct bpf_sock**, or **NULL** in case of failure.
+ *		For sockets with reuseport option, the **struct bpf_sock**
+ *		result is from **reuse->socks**\ [] using the hash of the tuple.
+ *
+ * struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
+ *	Description
+ *		Look for UDP socket matching *tuple*, optionally in a child
+ *		network namespace *netns*. The return value must be checked,
+ *		and if non-**NULL**, released via **bpf_sk_release**\ ().
+ *
+ *		The *ctx* should point to the context of the program, such as
+ *		the skb or socket (depending on the hook in use). This is used
+ *		to determine the base network namespace for the lookup.
+ *
+ *		*tuple_size* must be one of:
+ *
+ *		**sizeof**\ (*tuple*\ **->ipv4**)
+ *			Look for an IPv4 socket.
+ *		**sizeof**\ (*tuple*\ **->ipv6**)
+ *			Look for an IPv6 socket.
+ *
+ *		If the *netns* is a negative signed 32-bit integer, then the
+ *		socket lookup table in the netns associated with the *ctx* will
+ *		will be used. For the TC hooks, this is the netns of the device
+ *		in the skb. For socket hooks, this is the netns of the socket.
+ *		If *netns* is any other signed 32-bit value greater than or
+ *		equal to zero then it specifies the ID of the netns relative to
+ *		the netns associated with the *ctx*. *netns* values beyond the
+ *		range of 32-bit integers are reserved for future use.
+ *
+ *		All values for *flags* are reserved for future usage, and must
+ *		be left at zero.
+ *
+ *		This helper is available only if the kernel was compiled with
+ *		**CONFIG_NET** configuration option.
+ *	Return
+ *		Pointer to **struct bpf_sock**, or **NULL** in case of failure.
+ *		For sockets with reuseport option, the **struct bpf_sock**
+ *		result is from **reuse->socks**\ [] using the hash of the tuple.
+ *
+ * int bpf_sk_release(struct bpf_sock *sock)
+ *	Description
+ *		Release the reference held by *sock*. *sock* must be a
+ *		non-**NULL** pointer that was returned from
+ *		**bpf_sk_lookup_xxx**\ ().
+ *	Return
+ *		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_map_push_elem(struct bpf_map *map, const void *value, u64 flags)
+ * 	Description
+ * 		Push an element *value* in *map*. *flags* is one of:
+ *
+ * 		**BPF_EXIST**
+ * 			If the queue/stack is full, the oldest element is
+ * 			removed to make room for this.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_map_pop_elem(struct bpf_map *map, void *value)
+ * 	Description
+ * 		Pop an element from *map*.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_map_peek_elem(struct bpf_map *map, void *value)
+ * 	Description
+ * 		Get an element from *map* without removing it.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_msg_push_data(struct sk_buff *skb, u32 start, u32 len, u64 flags)
+ *	Description
+ *		For socket policies, insert *len* bytes into *msg* at offset
+ *		*start*.
+ *
+ *		If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
+ *		*msg* it may want to insert metadata or options into the *msg*.
+ *		This can later be read and used by any of the lower layer BPF
+ *		hooks.
+ *
+ *		This helper may fail if under memory pressure (a malloc
+ *		fails) in these cases BPF programs will get an appropriate
+ *		error and BPF programs will need to handle them.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_msg_pop_data(struct sk_msg_buff *msg, u32 start, u32 pop, u64 flags)
+ *	Description
+ *		Will remove *pop* bytes from a *msg* starting at byte *start*.
+ *		This may result in **ENOMEM** errors under certain situations if
+ *		an allocation and copy are required due to a full ring buffer.
+ *		However, the helper will try to avoid doing the allocation
+ *		if possible. Other errors can occur if input parameters are
+ *		invalid either due to *start* byte not being valid part of *msg*
+ *		payload and/or *pop* value being to large.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_rc_pointer_rel(void *ctx, s32 rel_x, s32 rel_y)
+ *	Description
+ *		This helper is used in programs implementing IR decoding, to
+ *		report a successfully decoded pointer movement.
+ *
+ *		The *ctx* should point to the lirc sample as passed into
+ *		the program.
+ *
+ *		This helper is only available is the kernel was compiled with
+ *		the **CONFIG_BPF_LIRC_MODE2** configuration option set to
+ *		"**y**".
+ *	Return
+ *		0
+ *
+ * int bpf_spin_lock(struct bpf_spin_lock *lock)
+ *	Description
+ *		Acquire a spinlock represented by the pointer *lock*, which is
+ *		stored as part of a value of a map. Taking the lock allows to
+ *		safely update the rest of the fields in that value. The
+ *		spinlock can (and must) later be released with a call to
+ *		**bpf_spin_unlock**\ (\ *lock*\ ).
+ *
+ *		Spinlocks in BPF programs come with a number of restrictions
+ *		and constraints:
+ *
+ *		* **bpf_spin_lock** objects are only allowed inside maps of
+ *		  types **BPF_MAP_TYPE_HASH** and **BPF_MAP_TYPE_ARRAY** (this
+ *		  list could be extended in the future).
+ *		* BTF description of the map is mandatory.
+ *		* The BPF program can take ONE lock at a time, since taking two
+ *		  or more could cause dead locks.
+ *		* Only one **struct bpf_spin_lock** is allowed per map element.
+ *		* When the lock is taken, calls (either BPF to BPF or helpers)
+ *		  are not allowed.
+ *		* The **BPF_LD_ABS** and **BPF_LD_IND** instructions are not
+ *		  allowed inside a spinlock-ed region.
+ *		* The BPF program MUST call **bpf_spin_unlock**\ () to release
+ *		  the lock, on all execution paths, before it returns.
+ *		* The BPF program can access **struct bpf_spin_lock** only via
+ *		  the **bpf_spin_lock**\ () and **bpf_spin_unlock**\ ()
+ *		  helpers. Loading or storing data into the **struct
+ *		  bpf_spin_lock** *lock*\ **;** field of a map is not allowed.
+ *		* To use the **bpf_spin_lock**\ () helper, the BTF description
+ *		  of the map value must be a struct and have **struct
+ *		  bpf_spin_lock** *anyname*\ **;** field at the top level.
+ *		  Nested lock inside another struct is not allowed.
+ *		* The **struct bpf_spin_lock** *lock* field in a map value must
+ *		  be aligned on a multiple of 4 bytes in that value.
+ *		* Syscall with command **BPF_MAP_LOOKUP_ELEM** does not copy
+ *		  the **bpf_spin_lock** field to user space.
+ *		* Syscall with command **BPF_MAP_UPDATE_ELEM**, or update from
+ *		  a BPF program, do not update the **bpf_spin_lock** field.
+ *		* **bpf_spin_lock** cannot be on the stack or inside a
+ *		  networking packet (it can only be inside of a map values).
+ *		* **bpf_spin_lock** is available to root only.
+ *		* Tracing programs and socket filter programs cannot use
+ *		  **bpf_spin_lock**\ () due to insufficient preemption checks
+ *		  (but this may change in the future).
+ *		* **bpf_spin_lock** is not allowed in inner maps of map-in-map.
+ *	Return
+ *		0
+ *
+ * int bpf_spin_unlock(struct bpf_spin_lock *lock)
+ *	Description
+ *		Release the *lock* previously locked by a call to
+ *		**bpf_spin_lock**\ (\ *lock*\ ).
+ *	Return
+ *		0
+ *
+ * struct bpf_sock *bpf_sk_fullsock(struct bpf_sock *sk)
+ *	Description
+ *		This helper gets a **struct bpf_sock** pointer such
+ *		that all the fields in this **bpf_sock** can be accessed.
+ *	Return
+ *		A **struct bpf_sock** pointer on success, or **NULL** in
+ *		case of failure.
+ *
+ * struct bpf_tcp_sock *bpf_tcp_sock(struct bpf_sock *sk)
+ *	Description
+ *		This helper gets a **struct bpf_tcp_sock** pointer from a
+ *		**struct bpf_sock** pointer.
+ *	Return
+ *		A **struct bpf_tcp_sock** pointer on success, or **NULL** in
+ *		case of failure.
+ *
+ * int bpf_skb_ecn_set_ce(struct sk_buf *skb)
+ *	Description
+ *		Set ECN (Explicit Congestion Notification) field of IP header
+ *		to **CE** (Congestion Encountered) if current value is **ECT**
+ *		(ECN Capable Transport). Otherwise, do nothing. Works with IPv6
+ *		and IPv4.
+ *	Return
+ *		1 if the **CE** flag is set (either by the current helper call
+ *		or because it was already present), 0 if it is not set.
+ *
+ * struct bpf_sock *bpf_get_listener_sock(struct bpf_sock *sk)
+ *	Description
+ *		Return a **struct bpf_sock** pointer in **TCP_LISTEN** state.
+ *		**bpf_sk_release**\ () is unnecessary and not allowed.
+ *	Return
+ *		A **struct bpf_sock** pointer on success, or **NULL** in
+ *		case of failure.
+ *
+ * struct bpf_sock *bpf_skc_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
+ *	Description
+ *		Look for TCP socket matching *tuple*, optionally in a child
+ *		network namespace *netns*. The return value must be checked,
+ *		and if non-**NULL**, released via **bpf_sk_release**\ ().
+ *
+ *		This function is identical to bpf_sk_lookup_tcp, except that it
+ *		also returns timewait or request sockets. Use bpf_sk_fullsock
+ *		or bpf_tcp_socket to access the full structure.
+ *
+ *		This helper is available only if the kernel was compiled with
+ *		**CONFIG_NET** configuration option.
+ *	Return
+ *		Pointer to **struct bpf_sock**, or **NULL** in case of failure.
+ *		For sockets with reuseport option, the **struct bpf_sock**
+ *		result is from **reuse->socks**\ [] using the hash of the tuple.
+ *
+ * int bpf_tcp_check_syncookie(struct bpf_sock *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
+ * 	Description
+ * 		Check whether iph and th contain a valid SYN cookie ACK for
+ * 		the listening socket in sk.
+ *
+ * 		iph points to the start of the IPv4 or IPv6 header, while
+ * 		iph_len contains sizeof(struct iphdr) or sizeof(struct ip6hdr).
+ *
+ * 		th points to the start of the TCP header, while th_len contains
+ * 		sizeof(struct tcphdr).
+ *
+ * 	Return
+ * 		0 if iph and th are a valid SYN cookie ACK, or a negative error
+ * 		otherwise.
+ */
+#define __BPF_FUNC_MAPPER(FN)		\
+	FN(unspec),			\
+	FN(map_lookup_elem),		\
+	FN(map_update_elem),		\
+	FN(map_delete_elem),		\
+	FN(probe_read),			\
+	FN(ktime_get_ns),		\
+	FN(trace_printk),		\
+	FN(get_prandom_u32),		\
+	FN(get_smp_processor_id),	\
+	FN(skb_store_bytes),		\
+	FN(l3_csum_replace),		\
+	FN(l4_csum_replace),		\
+	FN(tail_call),			\
+	FN(clone_redirect),		\
+	FN(get_current_pid_tgid),	\
+	FN(get_current_uid_gid),	\
+	FN(get_current_comm),		\
+	FN(get_cgroup_classid),		\
+	FN(skb_vlan_push),		\
+	FN(skb_vlan_pop),		\
+	FN(skb_get_tunnel_key),		\
+	FN(skb_set_tunnel_key),		\
+	FN(perf_event_read),		\
+	FN(redirect),			\
+	FN(get_route_realm),		\
+	FN(perf_event_output),		\
+	FN(skb_load_bytes),		\
+	FN(get_stackid),		\
+	FN(csum_diff),			\
+	FN(skb_get_tunnel_opt),		\
+	FN(skb_set_tunnel_opt),		\
+	FN(skb_change_proto),		\
+	FN(skb_change_type),		\
+	FN(skb_under_cgroup),		\
+	FN(get_hash_recalc),		\
+	FN(get_current_task),		\
+	FN(probe_write_user),		\
+	FN(current_task_under_cgroup),	\
+	FN(skb_change_tail),		\
+	FN(skb_pull_data),		\
+	FN(csum_update),		\
+	FN(set_hash_invalid),		\
+	FN(get_numa_node_id),		\
+	FN(skb_change_head),		\
+	FN(xdp_adjust_head),		\
+	FN(probe_read_str),		\
+	FN(get_socket_cookie),		\
+	FN(get_socket_uid),		\
+	FN(set_hash),			\
+	FN(setsockopt),			\
+	FN(skb_adjust_room),		\
+	FN(redirect_map),		\
+	FN(sk_redirect_map),		\
+	FN(sock_map_update),		\
+	FN(xdp_adjust_meta),		\
+	FN(perf_event_read_value),	\
+	FN(perf_prog_read_value),	\
+	FN(getsockopt),			\
+	FN(override_return),		\
+	FN(sock_ops_cb_flags_set),	\
+	FN(msg_redirect_map),		\
+	FN(msg_apply_bytes),		\
+	FN(msg_cork_bytes),		\
+	FN(msg_pull_data),		\
+	FN(bind),			\
+	FN(xdp_adjust_tail),		\
+	FN(skb_get_xfrm_state),		\
+	FN(get_stack),			\
+	FN(skb_load_bytes_relative),	\
+	FN(fib_lookup),			\
+	FN(sock_hash_update),		\
+	FN(msg_redirect_hash),		\
+	FN(sk_redirect_hash),		\
+	FN(lwt_push_encap),		\
+	FN(lwt_seg6_store_bytes),	\
+	FN(lwt_seg6_adjust_srh),	\
+	FN(lwt_seg6_action),		\
+	FN(rc_repeat),			\
+	FN(rc_keydown),			\
+	FN(skb_cgroup_id),		\
+	FN(get_current_cgroup_id),	\
+	FN(get_local_storage),		\
+	FN(sk_select_reuseport),	\
+	FN(skb_ancestor_cgroup_id),	\
+	FN(sk_lookup_tcp),		\
+	FN(sk_lookup_udp),		\
+	FN(sk_release),			\
+	FN(map_push_elem),		\
+	FN(map_pop_elem),		\
+	FN(map_peek_elem),		\
+	FN(msg_push_data),		\
+	FN(msg_pop_data),		\
+	FN(rc_pointer_rel),		\
+	FN(spin_lock),			\
+	FN(spin_unlock),		\
+	FN(sk_fullsock),		\
+	FN(tcp_sock),			\
+	FN(skb_ecn_set_ce),		\
+	FN(get_listener_sock),		\
+	FN(skc_lookup_tcp),		\
+	FN(tcp_check_syncookie),
+
+/* integer value in 'imm' field of BPF_CALL instruction selects which helper
+ * function eBPF program intends to call
+ */
+#define __BPF_ENUM_FN(x) BPF_FUNC_ ## x
+enum bpf_func_id {
+	__BPF_FUNC_MAPPER(__BPF_ENUM_FN)
+	__BPF_FUNC_MAX_ID,
+};
+#undef __BPF_ENUM_FN
+
+/* All flags used by eBPF helper functions, placed here. */
+
+/* BPF_FUNC_skb_store_bytes flags. */
+#define BPF_F_RECOMPUTE_CSUM		(1ULL << 0)
+#define BPF_F_INVALIDATE_HASH		(1ULL << 1)
+
+/* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
+ * First 4 bits are for passing the header field size.
+ */
+#define BPF_F_HDR_FIELD_MASK		0xfULL
+
+/* BPF_FUNC_l4_csum_replace flags. */
+#define BPF_F_PSEUDO_HDR		(1ULL << 4)
+#define BPF_F_MARK_MANGLED_0		(1ULL << 5)
+#define BPF_F_MARK_ENFORCE		(1ULL << 6)
+
+/* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
+#define BPF_F_INGRESS			(1ULL << 0)
+
+/* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
+#define BPF_F_TUNINFO_IPV6		(1ULL << 0)
+
+/* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */
+#define BPF_F_SKIP_FIELD_MASK		0xffULL
+#define BPF_F_USER_STACK		(1ULL << 8)
+/* flags used by BPF_FUNC_get_stackid only. */
+#define BPF_F_FAST_STACK_CMP		(1ULL << 9)
+#define BPF_F_REUSE_STACKID		(1ULL << 10)
+/* flags used by BPF_FUNC_get_stack only. */
+#define BPF_F_USER_BUILD_ID		(1ULL << 11)
+
+/* BPF_FUNC_skb_set_tunnel_key flags. */
+#define BPF_F_ZERO_CSUM_TX		(1ULL << 1)
+#define BPF_F_DONT_FRAGMENT		(1ULL << 2)
+#define BPF_F_SEQ_NUMBER		(1ULL << 3)
+
+/* BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and
+ * BPF_FUNC_perf_event_read_value flags.
+ */
+#define BPF_F_INDEX_MASK		0xffffffffULL
+#define BPF_F_CURRENT_CPU		BPF_F_INDEX_MASK
+/* BPF_FUNC_perf_event_output for sk_buff input context. */
+#define BPF_F_CTXLEN_MASK		(0xfffffULL << 32)
+
+/* Current network namespace */
+#define BPF_F_CURRENT_NETNS		(-1L)
+
+/* BPF_FUNC_skb_adjust_room flags. */
+#define BPF_F_ADJ_ROOM_FIXED_GSO	(1ULL << 0)
+
+#define BPF_F_ADJ_ROOM_ENCAP_L3_IPV4	(1ULL << 1)
+#define BPF_F_ADJ_ROOM_ENCAP_L3_IPV6	(1ULL << 2)
+#define BPF_F_ADJ_ROOM_ENCAP_L4_GRE	(1ULL << 3)
+#define BPF_F_ADJ_ROOM_ENCAP_L4_UDP	(1ULL << 4)
+
+/* Mode for BPF_FUNC_skb_adjust_room helper. */
+enum bpf_adj_room_mode {
+	BPF_ADJ_ROOM_NET,
+	BPF_ADJ_ROOM_MAC,
+};
+
+/* Mode for BPF_FUNC_skb_load_bytes_relative helper. */
+enum bpf_hdr_start_off {
+	BPF_HDR_START_MAC,
+	BPF_HDR_START_NET,
+};
+
+/* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */
+enum bpf_lwt_encap_mode {
+	BPF_LWT_ENCAP_SEG6,
+	BPF_LWT_ENCAP_SEG6_INLINE,
+	BPF_LWT_ENCAP_IP,
+};
+
+#define __bpf_md_ptr(type, name)	\
+union {					\
+	type name;			\
+	__u64 :64;			\
+} __attribute__((aligned(8)))
+
+/* user accessible mirror of in-kernel sk_buff.
+ * new fields can only be added to the end of this structure
+ */
+struct __sk_buff {
+	__u32 len;
+	__u32 pkt_type;
+	__u32 mark;
+	__u32 queue_mapping;
+	__u32 protocol;
+	__u32 vlan_present;
+	__u32 vlan_tci;
+	__u32 vlan_proto;
+	__u32 priority;
+	__u32 ingress_ifindex;
+	__u32 ifindex;
+	__u32 tc_index;
+	__u32 cb[5];
+	__u32 hash;
+	__u32 tc_classid;
+	__u32 data;
+	__u32 data_end;
+	__u32 napi_id;
+
+	/* Accessed by BPF_PROG_TYPE_sk_skb types from here to ... */
+	__u32 family;
+	__u32 remote_ip4;	/* Stored in network byte order */
+	__u32 local_ip4;	/* Stored in network byte order */
+	__u32 remote_ip6[4];	/* Stored in network byte order */
+	__u32 local_ip6[4];	/* Stored in network byte order */
+	__u32 remote_port;	/* Stored in network byte order */
+	__u32 local_port;	/* stored in host byte order */
+	/* ... here. */
+
+	__u32 data_meta;
+	__bpf_md_ptr(struct bpf_flow_keys *, flow_keys);
+	__u64 tstamp;
+	__u32 wire_len;
+	__u32 gso_segs;
+	__bpf_md_ptr(struct bpf_sock *, sk);
+};
+
+struct bpf_tunnel_key {
+	__u32 tunnel_id;
+	union {
+		__u32 remote_ipv4;
+		__u32 remote_ipv6[4];
+	};
+	__u8 tunnel_tos;
+	__u8 tunnel_ttl;
+	__u16 tunnel_ext;	/* Padding, future use. */
+	__u32 tunnel_label;
+};
+
+/* user accessible mirror of in-kernel xfrm_state.
+ * new fields can only be added to the end of this structure
+ */
+struct bpf_xfrm_state {
+	__u32 reqid;
+	__u32 spi;	/* Stored in network byte order */
+	__u16 family;
+	__u16 ext;	/* Padding, future use. */
+	union {
+		__u32 remote_ipv4;	/* Stored in network byte order */
+		__u32 remote_ipv6[4];	/* Stored in network byte order */
+	};
+};
+
+/* Generic BPF return codes which all BPF program types may support.
+ * The values are binary compatible with their TC_ACT_* counter-part to
+ * provide backwards compatibility with existing SCHED_CLS and SCHED_ACT
+ * programs.
+ *
+ * XDP is handled seprately, see XDP_*.
+ */
+enum bpf_ret_code {
+	BPF_OK = 0,
+	/* 1 reserved */
+	BPF_DROP = 2,
+	/* 3-6 reserved */
+	BPF_REDIRECT = 7,
+	/* >127 are reserved for prog type specific return codes.
+	 *
+	 * BPF_LWT_REROUTE: used by BPF_PROG_TYPE_LWT_IN and
+	 *    BPF_PROG_TYPE_LWT_XMIT to indicate that skb had been
+	 *    changed and should be routed based on its new L3 header.
+	 *    (This is an L3 redirect, as opposed to L2 redirect
+	 *    represented by BPF_REDIRECT above).
+	 */
+	BPF_LWT_REROUTE = 128,
+};
+
+struct bpf_sock {
+	__u32 bound_dev_if;
+	__u32 family;
+	__u32 type;
+	__u32 protocol;
+	__u32 mark;
+	__u32 priority;
+	/* IP address also allows 1 and 2 bytes access */
+	__u32 src_ip4;
+	__u32 src_ip6[4];
+	__u32 src_port;		/* host byte order */
+	__u32 dst_port;		/* network byte order */
+	__u32 dst_ip4;
+	__u32 dst_ip6[4];
+	__u32 state;
+};
+
+struct bpf_tcp_sock {
+	__u32 snd_cwnd;		/* Sending congestion window		*/
+	__u32 srtt_us;		/* smoothed round trip time << 3 in usecs */
+	__u32 rtt_min;
+	__u32 snd_ssthresh;	/* Slow start size threshold		*/
+	__u32 rcv_nxt;		/* What we want to receive next		*/
+	__u32 snd_nxt;		/* Next sequence we send		*/
+	__u32 snd_una;		/* First byte we want an ack for	*/
+	__u32 mss_cache;	/* Cached effective mss, not including SACKS */
+	__u32 ecn_flags;	/* ECN status bits.			*/
+	__u32 rate_delivered;	/* saved rate sample: packets delivered */
+	__u32 rate_interval_us;	/* saved rate sample: time elapsed */
+	__u32 packets_out;	/* Packets which are "in flight"	*/
+	__u32 retrans_out;	/* Retransmitted packets out		*/
+	__u32 total_retrans;	/* Total retransmits for entire connection */
+	__u32 segs_in;		/* RFC4898 tcpEStatsPerfSegsIn
+				 * total number of segments in.
+				 */
+	__u32 data_segs_in;	/* RFC4898 tcpEStatsPerfDataSegsIn
+				 * total number of data segments in.
+				 */
+	__u32 segs_out;		/* RFC4898 tcpEStatsPerfSegsOut
+				 * The total number of segments sent.
+				 */
+	__u32 data_segs_out;	/* RFC4898 tcpEStatsPerfDataSegsOut
+				 * total number of data segments sent.
+				 */
+	__u32 lost_out;		/* Lost packets			*/
+	__u32 sacked_out;	/* SACK'd packets			*/
+	__u64 bytes_received;	/* RFC4898 tcpEStatsAppHCThruOctetsReceived
+				 * sum(delta(rcv_nxt)), or how many bytes
+				 * were acked.
+				 */
+	__u64 bytes_acked;	/* RFC4898 tcpEStatsAppHCThruOctetsAcked
+				 * sum(delta(snd_una)), or how many bytes
+				 * were acked.
+				 */
+};
+
+struct bpf_sock_tuple {
+	union {
+		struct {
+			__be32 saddr;
+			__be32 daddr;
+			__be16 sport;
+			__be16 dport;
+		} ipv4;
+		struct {
+			__be32 saddr[4];
+			__be32 daddr[4];
+			__be16 sport;
+			__be16 dport;
+		} ipv6;
+	};
+};
+
+#define XDP_PACKET_HEADROOM 256
+
+/* User return codes for XDP prog type.
+ * A valid XDP program must return one of these defined values. All other
+ * return codes are reserved for future use. Unknown return codes will
+ * result in packet drops and a warning via bpf_warn_invalid_xdp_action().
+ */
+enum xdp_action {
+	XDP_ABORTED = 0,
+	XDP_DROP,
+	XDP_PASS,
+	XDP_TX,
+	XDP_REDIRECT,
+};
+
+/* user accessible metadata for XDP packet hook
+ * new fields must be added to the end of this structure
+ */
+struct xdp_md {
+	__u32 data;
+	__u32 data_end;
+	__u32 data_meta;
+	/* Below access go through struct xdp_rxq_info */
+	__u32 ingress_ifindex; /* rxq->dev->ifindex */
+	__u32 rx_queue_index;  /* rxq->queue_index  */
+};
+
+enum sk_action {
+	SK_DROP = 0,
+	SK_PASS,
+};
+
+/* user accessible metadata for SK_MSG packet hook, new fields must
+ * be added to the end of this structure
+ */
+struct sk_msg_md {
+	__bpf_md_ptr(void *, data);
+	__bpf_md_ptr(void *, data_end);
+
+	__u32 family;
+	__u32 remote_ip4;	/* Stored in network byte order */
+	__u32 local_ip4;	/* Stored in network byte order */
+	__u32 remote_ip6[4];	/* Stored in network byte order */
+	__u32 local_ip6[4];	/* Stored in network byte order */
+	__u32 remote_port;	/* Stored in network byte order */
+	__u32 local_port;	/* stored in host byte order */
+	__u32 size;		/* Total size of sk_msg */
+};
+
+struct sk_reuseport_md {
+	/*
+	 * Start of directly accessible data. It begins from
+	 * the tcp/udp header.
+	 */
+	__bpf_md_ptr(void *, data);
+	/* End of directly accessible data */
+	__bpf_md_ptr(void *, data_end);
+	/*
+	 * Total length of packet (starting from the tcp/udp header).
+	 * Note that the directly accessible bytes (data_end - data)
+	 * could be less than this "len".  Those bytes could be
+	 * indirectly read by a helper "bpf_skb_load_bytes()".
+	 */
+	__u32 len;
+	/*
+	 * Eth protocol in the mac header (network byte order). e.g.
+	 * ETH_P_IP(0x0800) and ETH_P_IPV6(0x86DD)
+	 */
+	__u32 eth_protocol;
+	__u32 ip_protocol;	/* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */
+	__u32 bind_inany;	/* Is sock bound to an INANY address? */
+	__u32 hash;		/* A hash of the packet 4 tuples */
+};
+
+#define BPF_TAG_SIZE	8
+
+struct bpf_prog_info {
+	__u32 type;
+	__u32 id;
+	__u8  tag[BPF_TAG_SIZE];
+	__u32 jited_prog_len;
+	__u32 xlated_prog_len;
+	__aligned_u64 jited_prog_insns;
+	__aligned_u64 xlated_prog_insns;
+	__u64 load_time;	/* ns since boottime */
+	__u32 created_by_uid;
+	__u32 nr_map_ids;
+	__aligned_u64 map_ids;
+	char name[BPF_OBJ_NAME_LEN];
+	__u32 ifindex;
+	__u32 gpl_compatible:1;
+	__u64 netns_dev;
+	__u64 netns_ino;
+	__u32 nr_jited_ksyms;
+	__u32 nr_jited_func_lens;
+	__aligned_u64 jited_ksyms;
+	__aligned_u64 jited_func_lens;
+	__u32 btf_id;
+	__u32 func_info_rec_size;
+	__aligned_u64 func_info;
+	__u32 nr_func_info;
+	__u32 nr_line_info;
+	__aligned_u64 line_info;
+	__aligned_u64 jited_line_info;
+	__u32 nr_jited_line_info;
+	__u32 line_info_rec_size;
+	__u32 jited_line_info_rec_size;
+	__u32 nr_prog_tags;
+	__aligned_u64 prog_tags;
+	__u64 run_time_ns;
+	__u64 run_cnt;
+} __attribute__((aligned(8)));
+
+struct bpf_map_info {
+	__u32 type;
+	__u32 id;
+	__u32 key_size;
+	__u32 value_size;
+	__u32 max_entries;
+	__u32 map_flags;
+	char  name[BPF_OBJ_NAME_LEN];
+	__u32 ifindex;
+	__u32 :32;
+	__u64 netns_dev;
+	__u64 netns_ino;
+	__u32 btf_id;
+	__u32 btf_key_type_id;
+	__u32 btf_value_type_id;
+} __attribute__((aligned(8)));
+
+struct bpf_btf_info {
+	__aligned_u64 btf;
+	__u32 btf_size;
+	__u32 id;
+} __attribute__((aligned(8)));
+
+/* User bpf_sock_addr struct to access socket fields and sockaddr struct passed
+ * by user and intended to be used by socket (e.g. to bind to, depends on
+ * attach attach type).
+ */
+struct bpf_sock_addr {
+	__u32 user_family;	/* Allows 4-byte read, but no write. */
+	__u32 user_ip4;		/* Allows 1,2,4-byte read and 4-byte write.
+				 * Stored in network byte order.
+				 */
+	__u32 user_ip6[4];	/* Allows 1,2,4-byte read an 4-byte write.
+				 * Stored in network byte order.
+				 */
+	__u32 user_port;	/* Allows 4-byte read and write.
+				 * Stored in network byte order
+				 */
+	__u32 family;		/* Allows 4-byte read, but no write */
+	__u32 type;		/* Allows 4-byte read, but no write */
+	__u32 protocol;		/* Allows 4-byte read, but no write */
+	__u32 msg_src_ip4;	/* Allows 1,2,4-byte read an 4-byte write.
+				 * Stored in network byte order.
+				 */
+	__u32 msg_src_ip6[4];	/* Allows 1,2,4-byte read an 4-byte write.
+				 * Stored in network byte order.
+				 */
+};
+
+/* User bpf_sock_ops struct to access socket values and specify request ops
+ * and their replies.
+ * Some of this fields are in network (bigendian) byte order and may need
+ * to be converted before use (bpf_ntohl() defined in samples/bpf/bpf_endian.h).
+ * New fields can only be added at the end of this structure
+ */
+struct bpf_sock_ops {
+	__u32 op;
+	union {
+		__u32 args[4];		/* Optionally passed to bpf program */
+		__u32 reply;		/* Returned by bpf program	    */
+		__u32 replylong[4];	/* Optionally returned by bpf prog  */
+	};
+	__u32 family;
+	__u32 remote_ip4;	/* Stored in network byte order */
+	__u32 local_ip4;	/* Stored in network byte order */
+	__u32 remote_ip6[4];	/* Stored in network byte order */
+	__u32 local_ip6[4];	/* Stored in network byte order */
+	__u32 remote_port;	/* Stored in network byte order */
+	__u32 local_port;	/* stored in host byte order */
+	__u32 is_fullsock;	/* Some TCP fields are only valid if
+				 * there is a full socket. If not, the
+				 * fields read as zero.
+				 */
+	__u32 snd_cwnd;
+	__u32 srtt_us;		/* Averaged RTT << 3 in usecs */
+	__u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */
+	__u32 state;
+	__u32 rtt_min;
+	__u32 snd_ssthresh;
+	__u32 rcv_nxt;
+	__u32 snd_nxt;
+	__u32 snd_una;
+	__u32 mss_cache;
+	__u32 ecn_flags;
+	__u32 rate_delivered;
+	__u32 rate_interval_us;
+	__u32 packets_out;
+	__u32 retrans_out;
+	__u32 total_retrans;
+	__u32 segs_in;
+	__u32 data_segs_in;
+	__u32 segs_out;
+	__u32 data_segs_out;
+	__u32 lost_out;
+	__u32 sacked_out;
+	__u32 sk_txhash;
+	__u64 bytes_received;
+	__u64 bytes_acked;
+};
+
+/* Definitions for bpf_sock_ops_cb_flags */
+#define BPF_SOCK_OPS_RTO_CB_FLAG	(1<<0)
+#define BPF_SOCK_OPS_RETRANS_CB_FLAG	(1<<1)
+#define BPF_SOCK_OPS_STATE_CB_FLAG	(1<<2)
+#define BPF_SOCK_OPS_ALL_CB_FLAGS       0x7		/* Mask of all currently
+							 * supported cb flags
+							 */
+
+/* List of known BPF sock_ops operators.
+ * New entries can only be added at the end
+ */
+enum {
+	BPF_SOCK_OPS_VOID,
+	BPF_SOCK_OPS_TIMEOUT_INIT,	/* Should return SYN-RTO value to use or
+					 * -1 if default value should be used
+					 */
+	BPF_SOCK_OPS_RWND_INIT,		/* Should return initial advertized
+					 * window (in packets) or -1 if default
+					 * value should be used
+					 */
+	BPF_SOCK_OPS_TCP_CONNECT_CB,	/* Calls BPF program right before an
+					 * active connection is initialized
+					 */
+	BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB,	/* Calls BPF program when an
+						 * active connection is
+						 * established
+						 */
+	BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB,	/* Calls BPF program when a
+						 * passive connection is
+						 * established
+						 */
+	BPF_SOCK_OPS_NEEDS_ECN,		/* If connection's congestion control
+					 * needs ECN
+					 */
+	BPF_SOCK_OPS_BASE_RTT,		/* Get base RTT. The correct value is
+					 * based on the path and may be
+					 * dependent on the congestion control
+					 * algorithm. In general it indicates
+					 * a congestion threshold. RTTs above
+					 * this indicate congestion
+					 */
+	BPF_SOCK_OPS_RTO_CB,		/* Called when an RTO has triggered.
+					 * Arg1: value of icsk_retransmits
+					 * Arg2: value of icsk_rto
+					 * Arg3: whether RTO has expired
+					 */
+	BPF_SOCK_OPS_RETRANS_CB,	/* Called when skb is retransmitted.
+					 * Arg1: sequence number of 1st byte
+					 * Arg2: # segments
+					 * Arg3: return value of
+					 *       tcp_transmit_skb (0 => success)
+					 */
+	BPF_SOCK_OPS_STATE_CB,		/* Called when TCP changes state.
+					 * Arg1: old_state
+					 * Arg2: new_state
+					 */
+	BPF_SOCK_OPS_TCP_LISTEN_CB,	/* Called on listen(2), right after
+					 * socket transition to LISTEN state.
+					 */
+};
+
+/* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
+ * changes between the TCP and BPF versions. Ideally this should never happen.
+ * If it does, we need to add code to convert them before calling
+ * the BPF sock_ops function.
+ */
+enum {
+	BPF_TCP_ESTABLISHED = 1,
+	BPF_TCP_SYN_SENT,
+	BPF_TCP_SYN_RECV,
+	BPF_TCP_FIN_WAIT1,
+	BPF_TCP_FIN_WAIT2,
+	BPF_TCP_TIME_WAIT,
+	BPF_TCP_CLOSE,
+	BPF_TCP_CLOSE_WAIT,
+	BPF_TCP_LAST_ACK,
+	BPF_TCP_LISTEN,
+	BPF_TCP_CLOSING,	/* Now a valid state */
+	BPF_TCP_NEW_SYN_RECV,
+
+	BPF_TCP_MAX_STATES	/* Leave at the end! */
+};
+
+#define TCP_BPF_IW		1001	/* Set TCP initial congestion window */
+#define TCP_BPF_SNDCWND_CLAMP	1002	/* Set sndcwnd_clamp */
+
+struct bpf_perf_event_value {
+	__u64 counter;
+	__u64 enabled;
+	__u64 running;
+};
+
+#define BPF_DEVCG_ACC_MKNOD	(1ULL << 0)
+#define BPF_DEVCG_ACC_READ	(1ULL << 1)
+#define BPF_DEVCG_ACC_WRITE	(1ULL << 2)
+
+#define BPF_DEVCG_DEV_BLOCK	(1ULL << 0)
+#define BPF_DEVCG_DEV_CHAR	(1ULL << 1)
+
+struct bpf_cgroup_dev_ctx {
+	/* access_type encoded as (BPF_DEVCG_ACC_* << 16) | BPF_DEVCG_DEV_* */
+	__u32 access_type;
+	__u32 major;
+	__u32 minor;
+};
+
+struct bpf_raw_tracepoint_args {
+	__u64 args[0];
+};
+
+/* DIRECT:  Skip the FIB rules and go to FIB table associated with device
+ * OUTPUT:  Do lookup from egress perspective; default is ingress
+ */
+#define BPF_FIB_LOOKUP_DIRECT  BIT(0)
+#define BPF_FIB_LOOKUP_OUTPUT  BIT(1)
+
+enum {
+	BPF_FIB_LKUP_RET_SUCCESS,      /* lookup successful */
+	BPF_FIB_LKUP_RET_BLACKHOLE,    /* dest is blackholed; can be dropped */
+	BPF_FIB_LKUP_RET_UNREACHABLE,  /* dest is unreachable; can be dropped */
+	BPF_FIB_LKUP_RET_PROHIBIT,     /* dest not allowed; can be dropped */
+	BPF_FIB_LKUP_RET_NOT_FWDED,    /* packet is not forwarded */
+	BPF_FIB_LKUP_RET_FWD_DISABLED, /* fwding is not enabled on ingress */
+	BPF_FIB_LKUP_RET_UNSUPP_LWT,   /* fwd requires encapsulation */
+	BPF_FIB_LKUP_RET_NO_NEIGH,     /* no neighbor entry for nh */
+	BPF_FIB_LKUP_RET_FRAG_NEEDED,  /* fragmentation required to fwd */
+};
+
+struct bpf_fib_lookup {
+	/* input:  network family for lookup (AF_INET, AF_INET6)
+	 * output: network family of egress nexthop
+	 */
+	__u8	family;
+
+	/* set if lookup is to consider L4 data - e.g., FIB rules */
+	__u8	l4_protocol;
+	__be16	sport;
+	__be16	dport;
+
+	/* total length of packet from network header - used for MTU check */
+	__u16	tot_len;
+
+	/* input: L3 device index for lookup
+	 * output: device index from FIB lookup
+	 */
+	__u32	ifindex;
+
+	union {
+		/* inputs to lookup */
+		__u8	tos;		/* AF_INET  */
+		__be32	flowinfo;	/* AF_INET6, flow_label + priority */
+
+		/* output: metric of fib result (IPv4/IPv6 only) */
+		__u32	rt_metric;
+	};
+
+	union {
+		__be32		ipv4_src;
+		__u32		ipv6_src[4];  /* in6_addr; network order */
+	};
+
+	/* input to bpf_fib_lookup, ipv{4,6}_dst is destination address in
+	 * network header. output: bpf_fib_lookup sets to gateway address
+	 * if FIB lookup returns gateway route
+	 */
+	union {
+		__be32		ipv4_dst;
+		__u32		ipv6_dst[4];  /* in6_addr; network order */
+	};
+
+	/* output */
+	__be16	h_vlan_proto;
+	__be16	h_vlan_TCI;
+	__u8	smac[6];     /* ETH_ALEN */
+	__u8	dmac[6];     /* ETH_ALEN */
+};
+
+enum bpf_task_fd_type {
+	BPF_FD_TYPE_RAW_TRACEPOINT,	/* tp name */
+	BPF_FD_TYPE_TRACEPOINT,		/* tp name */
+	BPF_FD_TYPE_KPROBE,		/* (symbol + offset) or addr */
+	BPF_FD_TYPE_KRETPROBE,		/* (symbol + offset) or addr */
+	BPF_FD_TYPE_UPROBE,		/* filename + offset */
+	BPF_FD_TYPE_URETPROBE,		/* filename + offset */
+};
+
+struct bpf_flow_keys {
+	__u16	nhoff;
+	__u16	thoff;
+	__u16	addr_proto;			/* ETH_P_* of valid addrs */
+	__u8	is_frag;
+	__u8	is_first_frag;
+	__u8	is_encap;
+	__u8	ip_proto;
+	__be16	n_proto;
+	__be16	sport;
+	__be16	dport;
+	union {
+		struct {
+			__be32	ipv4_src;
+			__be32	ipv4_dst;
+		};
+		struct {
+			__u32	ipv6_src[4];	/* in6_addr; network order */
+			__u32	ipv6_dst[4];	/* in6_addr; network order */
+		};
+	};
+};
+
+struct bpf_func_info {
+	__u32	insn_off;
+	__u32	type_id;
+};
+
+#define BPF_LINE_INFO_LINE_NUM(line_col)	((line_col) >> 10)
+#define BPF_LINE_INFO_LINE_COL(line_col)	((line_col) & 0x3ff)
+
+struct bpf_line_info {
+	__u32	insn_off;
+	__u32	file_name_off;
+	__u32	line_off;
+	__u32	line_col;
+};
+
+struct bpf_spin_lock {
+	__u32	val;
+};
+#endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/src/xdp/include/linux/err.h b/src/xdp/include/linux/err.h
new file mode 100644
index 000000000..a3db4cf5e
--- /dev/null
+++ b/src/xdp/include/linux/err.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+#ifndef __LINUX_ERR_H
+#define __LINUX_ERR_H
+
+#include <linux/types.h>
+#include <asm/errno.h>
+
+#define MAX_ERRNO       4095
+
+#define IS_ERR_VALUE(x) ((x) >= (unsigned long)-MAX_ERRNO)
+
+static inline void * ERR_PTR(long error_)
+{
+	return (void *) error_;
+}
+
+static inline long PTR_ERR(const void *ptr)
+{
+	return (long) ptr;
+}
+
+static inline bool IS_ERR(const void *ptr)
+{
+	return IS_ERR_VALUE((unsigned long)ptr);
+}
+
+static inline bool IS_ERR_OR_NULL(const void *ptr)
+{
+	return (!ptr) || IS_ERR_VALUE((unsigned long)ptr);
+}
+
+#endif
diff --git a/src/xdp/include/linux/if_link.h b/src/xdp/include/linux/if_link.h
new file mode 100644
index 000000000..5b225ff63
--- /dev/null
+++ b/src/xdp/include/linux/if_link.h
@@ -0,0 +1,1025 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_LINUX_IF_LINK_H
+#define _UAPI_LINUX_IF_LINK_H
+
+#include <linux/types.h>
+#include <linux/netlink.h>
+
+/* This struct should be in sync with struct rtnl_link_stats64 */
+struct rtnl_link_stats {
+	__u32	rx_packets;		/* total packets received	*/
+	__u32	tx_packets;		/* total packets transmitted	*/
+	__u32	rx_bytes;		/* total bytes received 	*/
+	__u32	tx_bytes;		/* total bytes transmitted	*/
+	__u32	rx_errors;		/* bad packets received		*/
+	__u32	tx_errors;		/* packet transmit problems	*/
+	__u32	rx_dropped;		/* no space in linux buffers	*/
+	__u32	tx_dropped;		/* no space available in linux	*/
+	__u32	multicast;		/* multicast packets received	*/
+	__u32	collisions;
+
+	/* detailed rx_errors: */
+	__u32	rx_length_errors;
+	__u32	rx_over_errors;		/* receiver ring buff overflow	*/
+	__u32	rx_crc_errors;		/* recved pkt with crc error	*/
+	__u32	rx_frame_errors;	/* recv'd frame alignment error */
+	__u32	rx_fifo_errors;		/* recv'r fifo overrun		*/
+	__u32	rx_missed_errors;	/* receiver missed packet	*/
+
+	/* detailed tx_errors */
+	__u32	tx_aborted_errors;
+	__u32	tx_carrier_errors;
+	__u32	tx_fifo_errors;
+	__u32	tx_heartbeat_errors;
+	__u32	tx_window_errors;
+
+	/* for cslip etc */
+	__u32	rx_compressed;
+	__u32	tx_compressed;
+
+	__u32	rx_nohandler;		/* dropped, no handler found	*/
+};
+
+/* The main device statistics structure */
+struct rtnl_link_stats64 {
+	__u64	rx_packets;		/* total packets received	*/
+	__u64	tx_packets;		/* total packets transmitted	*/
+	__u64	rx_bytes;		/* total bytes received 	*/
+	__u64	tx_bytes;		/* total bytes transmitted	*/
+	__u64	rx_errors;		/* bad packets received		*/
+	__u64	tx_errors;		/* packet transmit problems	*/
+	__u64	rx_dropped;		/* no space in linux buffers	*/
+	__u64	tx_dropped;		/* no space available in linux	*/
+	__u64	multicast;		/* multicast packets received	*/
+	__u64	collisions;
+
+	/* detailed rx_errors: */
+	__u64	rx_length_errors;
+	__u64	rx_over_errors;		/* receiver ring buff overflow	*/
+	__u64	rx_crc_errors;		/* recved pkt with crc error	*/
+	__u64	rx_frame_errors;	/* recv'd frame alignment error */
+	__u64	rx_fifo_errors;		/* recv'r fifo overrun		*/
+	__u64	rx_missed_errors;	/* receiver missed packet	*/
+
+	/* detailed tx_errors */
+	__u64	tx_aborted_errors;
+	__u64	tx_carrier_errors;
+	__u64	tx_fifo_errors;
+	__u64	tx_heartbeat_errors;
+	__u64	tx_window_errors;
+
+	/* for cslip etc */
+	__u64	rx_compressed;
+	__u64	tx_compressed;
+
+	__u64	rx_nohandler;		/* dropped, no handler found	*/
+};
+
+/* The struct should be in sync with struct ifmap */
+struct rtnl_link_ifmap {
+	__u64	mem_start;
+	__u64	mem_end;
+	__u64	base_addr;
+	__u16	irq;
+	__u8	dma;
+	__u8	port;
+};
+
+/*
+ * IFLA_AF_SPEC
+ *   Contains nested attributes for address family specific attributes.
+ *   Each address family may create a attribute with the address family
+ *   number as type and create its own attribute structure in it.
+ *
+ *   Example:
+ *   [IFLA_AF_SPEC] = {
+ *       [AF_INET] = {
+ *           [IFLA_INET_CONF] = ...,
+ *       },
+ *       [AF_INET6] = {
+ *           [IFLA_INET6_FLAGS] = ...,
+ *           [IFLA_INET6_CONF] = ...,
+ *       }
+ *   }
+ */
+
+enum {
+	IFLA_UNSPEC,
+	IFLA_ADDRESS,
+	IFLA_BROADCAST,
+	IFLA_IFNAME,
+	IFLA_MTU,
+	IFLA_LINK,
+	IFLA_QDISC,
+	IFLA_STATS,
+	IFLA_COST,
+#define IFLA_COST IFLA_COST
+	IFLA_PRIORITY,
+#define IFLA_PRIORITY IFLA_PRIORITY
+	IFLA_MASTER,
+#define IFLA_MASTER IFLA_MASTER
+	IFLA_WIRELESS,		/* Wireless Extension event - see wireless.h */
+#define IFLA_WIRELESS IFLA_WIRELESS
+	IFLA_PROTINFO,		/* Protocol specific information for a link */
+#define IFLA_PROTINFO IFLA_PROTINFO
+	IFLA_TXQLEN,
+#define IFLA_TXQLEN IFLA_TXQLEN
+	IFLA_MAP,
+#define IFLA_MAP IFLA_MAP
+	IFLA_WEIGHT,
+#define IFLA_WEIGHT IFLA_WEIGHT
+	IFLA_OPERSTATE,
+	IFLA_LINKMODE,
+	IFLA_LINKINFO,
+#define IFLA_LINKINFO IFLA_LINKINFO
+	IFLA_NET_NS_PID,
+	IFLA_IFALIAS,
+	IFLA_NUM_VF,		/* Number of VFs if device is SR-IOV PF */
+	IFLA_VFINFO_LIST,
+	IFLA_STATS64,
+	IFLA_VF_PORTS,
+	IFLA_PORT_SELF,
+	IFLA_AF_SPEC,
+	IFLA_GROUP,		/* Group the device belongs to */
+	IFLA_NET_NS_FD,
+	IFLA_EXT_MASK,		/* Extended info mask, VFs, etc */
+	IFLA_PROMISCUITY,	/* Promiscuity count: > 0 means acts PROMISC */
+#define IFLA_PROMISCUITY IFLA_PROMISCUITY
+	IFLA_NUM_TX_QUEUES,
+	IFLA_NUM_RX_QUEUES,
+	IFLA_CARRIER,
+	IFLA_PHYS_PORT_ID,
+	IFLA_CARRIER_CHANGES,
+	IFLA_PHYS_SWITCH_ID,
+	IFLA_LINK_NETNSID,
+	IFLA_PHYS_PORT_NAME,
+	IFLA_PROTO_DOWN,
+	IFLA_GSO_MAX_SEGS,
+	IFLA_GSO_MAX_SIZE,
+	IFLA_PAD,
+	IFLA_XDP,
+	IFLA_EVENT,
+	IFLA_NEW_NETNSID,
+	IFLA_IF_NETNSID,
+	IFLA_TARGET_NETNSID = IFLA_IF_NETNSID, /* new alias */
+	IFLA_CARRIER_UP_COUNT,
+	IFLA_CARRIER_DOWN_COUNT,
+	IFLA_NEW_IFINDEX,
+	IFLA_MIN_MTU,
+	IFLA_MAX_MTU,
+	__IFLA_MAX
+};
+
+
+#define IFLA_MAX (__IFLA_MAX - 1)
+
+/* backwards compatibility for userspace */
+#ifndef __KERNEL__
+#define IFLA_RTA(r)  ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct ifinfomsg))))
+#define IFLA_PAYLOAD(n) NLMSG_PAYLOAD(n,sizeof(struct ifinfomsg))
+#endif
+
+enum {
+	IFLA_INET_UNSPEC,
+	IFLA_INET_CONF,
+	__IFLA_INET_MAX,
+};
+
+#define IFLA_INET_MAX (__IFLA_INET_MAX - 1)
+
+/* ifi_flags.
+
+   IFF_* flags.
+
+   The only change is:
+   IFF_LOOPBACK, IFF_BROADCAST and IFF_POINTOPOINT are
+   more not changeable by user. They describe link media
+   characteristics and set by device driver.
+
+   Comments:
+   - Combination IFF_BROADCAST|IFF_POINTOPOINT is invalid
+   - If neither of these three flags are set;
+     the interface is NBMA.
+
+   - IFF_MULTICAST does not mean anything special:
+   multicasts can be used on all not-NBMA links.
+   IFF_MULTICAST means that this media uses special encapsulation
+   for multicast frames. Apparently, all IFF_POINTOPOINT and
+   IFF_BROADCAST devices are able to use multicasts too.
+ */
+
+/* IFLA_LINK.
+   For usual devices it is equal ifi_index.
+   If it is a "virtual interface" (f.e. tunnel), ifi_link
+   can point to real physical interface (f.e. for bandwidth calculations),
+   or maybe 0, what means, that real media is unknown (usual
+   for IPIP tunnels, when route to endpoint is allowed to change)
+ */
+
+/* Subtype attributes for IFLA_PROTINFO */
+enum {
+	IFLA_INET6_UNSPEC,
+	IFLA_INET6_FLAGS,	/* link flags			*/
+	IFLA_INET6_CONF,	/* sysctl parameters		*/
+	IFLA_INET6_STATS,	/* statistics			*/
+	IFLA_INET6_MCAST,	/* MC things. What of them?	*/
+	IFLA_INET6_CACHEINFO,	/* time values and max reasm size */
+	IFLA_INET6_ICMP6STATS,	/* statistics (icmpv6)		*/
+	IFLA_INET6_TOKEN,	/* device token			*/
+	IFLA_INET6_ADDR_GEN_MODE, /* implicit address generator mode */
+	__IFLA_INET6_MAX
+};
+
+#define IFLA_INET6_MAX	(__IFLA_INET6_MAX - 1)
+
+enum in6_addr_gen_mode {
+	IN6_ADDR_GEN_MODE_EUI64,
+	IN6_ADDR_GEN_MODE_NONE,
+	IN6_ADDR_GEN_MODE_STABLE_PRIVACY,
+	IN6_ADDR_GEN_MODE_RANDOM,
+};
+
+/* Bridge section */
+
+enum {
+	IFLA_BR_UNSPEC,
+	IFLA_BR_FORWARD_DELAY,
+	IFLA_BR_HELLO_TIME,
+	IFLA_BR_MAX_AGE,
+	IFLA_BR_AGEING_TIME,
+	IFLA_BR_STP_STATE,
+	IFLA_BR_PRIORITY,
+	IFLA_BR_VLAN_FILTERING,
+	IFLA_BR_VLAN_PROTOCOL,
+	IFLA_BR_GROUP_FWD_MASK,
+	IFLA_BR_ROOT_ID,
+	IFLA_BR_BRIDGE_ID,
+	IFLA_BR_ROOT_PORT,
+	IFLA_BR_ROOT_PATH_COST,
+	IFLA_BR_TOPOLOGY_CHANGE,
+	IFLA_BR_TOPOLOGY_CHANGE_DETECTED,
+	IFLA_BR_HELLO_TIMER,
+	IFLA_BR_TCN_TIMER,
+	IFLA_BR_TOPOLOGY_CHANGE_TIMER,
+	IFLA_BR_GC_TIMER,
+	IFLA_BR_GROUP_ADDR,
+	IFLA_BR_FDB_FLUSH,
+	IFLA_BR_MCAST_ROUTER,
+	IFLA_BR_MCAST_SNOOPING,
+	IFLA_BR_MCAST_QUERY_USE_IFADDR,
+	IFLA_BR_MCAST_QUERIER,
+	IFLA_BR_MCAST_HASH_ELASTICITY,
+	IFLA_BR_MCAST_HASH_MAX,
+	IFLA_BR_MCAST_LAST_MEMBER_CNT,
+	IFLA_BR_MCAST_STARTUP_QUERY_CNT,
+	IFLA_BR_MCAST_LAST_MEMBER_INTVL,
+	IFLA_BR_MCAST_MEMBERSHIP_INTVL,
+	IFLA_BR_MCAST_QUERIER_INTVL,
+	IFLA_BR_MCAST_QUERY_INTVL,
+	IFLA_BR_MCAST_QUERY_RESPONSE_INTVL,
+	IFLA_BR_MCAST_STARTUP_QUERY_INTVL,
+	IFLA_BR_NF_CALL_IPTABLES,
+	IFLA_BR_NF_CALL_IP6TABLES,
+	IFLA_BR_NF_CALL_ARPTABLES,
+	IFLA_BR_VLAN_DEFAULT_PVID,
+	IFLA_BR_PAD,
+	IFLA_BR_VLAN_STATS_ENABLED,
+	IFLA_BR_MCAST_STATS_ENABLED,
+	IFLA_BR_MCAST_IGMP_VERSION,
+	IFLA_BR_MCAST_MLD_VERSION,
+	IFLA_BR_VLAN_STATS_PER_PORT,
+	IFLA_BR_MULTI_BOOLOPT,
+	__IFLA_BR_MAX,
+};
+
+#define IFLA_BR_MAX	(__IFLA_BR_MAX - 1)
+
+struct ifla_bridge_id {
+	__u8	prio[2];
+	__u8	addr[6]; /* ETH_ALEN */
+};
+
+enum {
+	BRIDGE_MODE_UNSPEC,
+	BRIDGE_MODE_HAIRPIN,
+};
+
+enum {
+	IFLA_BRPORT_UNSPEC,
+	IFLA_BRPORT_STATE,	/* Spanning tree state     */
+	IFLA_BRPORT_PRIORITY,	/* "             priority  */
+	IFLA_BRPORT_COST,	/* "             cost      */
+	IFLA_BRPORT_MODE,	/* mode (hairpin)          */
+	IFLA_BRPORT_GUARD,	/* bpdu guard              */
+	IFLA_BRPORT_PROTECT,	/* root port protection    */
+	IFLA_BRPORT_FAST_LEAVE,	/* multicast fast leave    */
+	IFLA_BRPORT_LEARNING,	/* mac learning */
+	IFLA_BRPORT_UNICAST_FLOOD, /* flood unicast traffic */
+	IFLA_BRPORT_PROXYARP,	/* proxy ARP */
+	IFLA_BRPORT_LEARNING_SYNC, /* mac learning sync from device */
+	IFLA_BRPORT_PROXYARP_WIFI, /* proxy ARP for Wi-Fi */
+	IFLA_BRPORT_ROOT_ID,	/* designated root */
+	IFLA_BRPORT_BRIDGE_ID,	/* designated bridge */
+	IFLA_BRPORT_DESIGNATED_PORT,
+	IFLA_BRPORT_DESIGNATED_COST,
+	IFLA_BRPORT_ID,
+	IFLA_BRPORT_NO,
+	IFLA_BRPORT_TOPOLOGY_CHANGE_ACK,
+	IFLA_BRPORT_CONFIG_PENDING,
+	IFLA_BRPORT_MESSAGE_AGE_TIMER,
+	IFLA_BRPORT_FORWARD_DELAY_TIMER,
+	IFLA_BRPORT_HOLD_TIMER,
+	IFLA_BRPORT_FLUSH,
+	IFLA_BRPORT_MULTICAST_ROUTER,
+	IFLA_BRPORT_PAD,
+	IFLA_BRPORT_MCAST_FLOOD,
+	IFLA_BRPORT_MCAST_TO_UCAST,
+	IFLA_BRPORT_VLAN_TUNNEL,
+	IFLA_BRPORT_BCAST_FLOOD,
+	IFLA_BRPORT_GROUP_FWD_MASK,
+	IFLA_BRPORT_NEIGH_SUPPRESS,
+	IFLA_BRPORT_ISOLATED,
+	IFLA_BRPORT_BACKUP_PORT,
+	__IFLA_BRPORT_MAX
+};
+#define IFLA_BRPORT_MAX (__IFLA_BRPORT_MAX - 1)
+
+struct ifla_cacheinfo {
+	__u32	max_reasm_len;
+	__u32	tstamp;		/* ipv6InterfaceTable updated timestamp */
+	__u32	reachable_time;
+	__u32	retrans_time;
+};
+
+enum {
+	IFLA_INFO_UNSPEC,
+	IFLA_INFO_KIND,
+	IFLA_INFO_DATA,
+	IFLA_INFO_XSTATS,
+	IFLA_INFO_SLAVE_KIND,
+	IFLA_INFO_SLAVE_DATA,
+	__IFLA_INFO_MAX,
+};
+
+#define IFLA_INFO_MAX	(__IFLA_INFO_MAX - 1)
+
+/* VLAN section */
+
+enum {
+	IFLA_VLAN_UNSPEC,
+	IFLA_VLAN_ID,
+	IFLA_VLAN_FLAGS,
+	IFLA_VLAN_EGRESS_QOS,
+	IFLA_VLAN_INGRESS_QOS,
+	IFLA_VLAN_PROTOCOL,
+	__IFLA_VLAN_MAX,
+};
+
+#define IFLA_VLAN_MAX	(__IFLA_VLAN_MAX - 1)
+
+struct ifla_vlan_flags {
+	__u32	flags;
+	__u32	mask;
+};
+
+enum {
+	IFLA_VLAN_QOS_UNSPEC,
+	IFLA_VLAN_QOS_MAPPING,
+	__IFLA_VLAN_QOS_MAX
+};
+
+#define IFLA_VLAN_QOS_MAX	(__IFLA_VLAN_QOS_MAX - 1)
+
+struct ifla_vlan_qos_mapping {
+	__u32 from;
+	__u32 to;
+};
+
+/* MACVLAN section */
+enum {
+	IFLA_MACVLAN_UNSPEC,
+	IFLA_MACVLAN_MODE,
+	IFLA_MACVLAN_FLAGS,
+	IFLA_MACVLAN_MACADDR_MODE,
+	IFLA_MACVLAN_MACADDR,
+	IFLA_MACVLAN_MACADDR_DATA,
+	IFLA_MACVLAN_MACADDR_COUNT,
+	__IFLA_MACVLAN_MAX,
+};
+
+#define IFLA_MACVLAN_MAX (__IFLA_MACVLAN_MAX - 1)
+
+enum macvlan_mode {
+	MACVLAN_MODE_PRIVATE = 1, /* don't talk to other macvlans */
+	MACVLAN_MODE_VEPA    = 2, /* talk to other ports through ext bridge */
+	MACVLAN_MODE_BRIDGE  = 4, /* talk to bridge ports directly */
+	MACVLAN_MODE_PASSTHRU = 8,/* take over the underlying device */
+	MACVLAN_MODE_SOURCE  = 16,/* use source MAC address list to assign */
+};
+
+enum macvlan_macaddr_mode {
+	MACVLAN_MACADDR_ADD,
+	MACVLAN_MACADDR_DEL,
+	MACVLAN_MACADDR_FLUSH,
+	MACVLAN_MACADDR_SET,
+};
+
+#define MACVLAN_FLAG_NOPROMISC	1
+
+/* VRF section */
+enum {
+	IFLA_VRF_UNSPEC,
+	IFLA_VRF_TABLE,
+	__IFLA_VRF_MAX
+};
+
+#define IFLA_VRF_MAX (__IFLA_VRF_MAX - 1)
+
+enum {
+	IFLA_VRF_PORT_UNSPEC,
+	IFLA_VRF_PORT_TABLE,
+	__IFLA_VRF_PORT_MAX
+};
+
+#define IFLA_VRF_PORT_MAX (__IFLA_VRF_PORT_MAX - 1)
+
+/* MACSEC section */
+enum {
+	IFLA_MACSEC_UNSPEC,
+	IFLA_MACSEC_SCI,
+	IFLA_MACSEC_PORT,
+	IFLA_MACSEC_ICV_LEN,
+	IFLA_MACSEC_CIPHER_SUITE,
+	IFLA_MACSEC_WINDOW,
+	IFLA_MACSEC_ENCODING_SA,
+	IFLA_MACSEC_ENCRYPT,
+	IFLA_MACSEC_PROTECT,
+	IFLA_MACSEC_INC_SCI,
+	IFLA_MACSEC_ES,
+	IFLA_MACSEC_SCB,
+	IFLA_MACSEC_REPLAY_PROTECT,
+	IFLA_MACSEC_VALIDATION,
+	IFLA_MACSEC_PAD,
+	__IFLA_MACSEC_MAX,
+};
+
+#define IFLA_MACSEC_MAX (__IFLA_MACSEC_MAX - 1)
+
+/* XFRM section */
+enum {
+	IFLA_XFRM_UNSPEC,
+	IFLA_XFRM_LINK,
+	IFLA_XFRM_IF_ID,
+	__IFLA_XFRM_MAX
+};
+
+#define IFLA_XFRM_MAX (__IFLA_XFRM_MAX - 1)
+
+enum macsec_validation_type {
+	MACSEC_VALIDATE_DISABLED = 0,
+	MACSEC_VALIDATE_CHECK = 1,
+	MACSEC_VALIDATE_STRICT = 2,
+	__MACSEC_VALIDATE_END,
+	MACSEC_VALIDATE_MAX = __MACSEC_VALIDATE_END - 1,
+};
+
+/* IPVLAN section */
+enum {
+	IFLA_IPVLAN_UNSPEC,
+	IFLA_IPVLAN_MODE,
+	IFLA_IPVLAN_FLAGS,
+	__IFLA_IPVLAN_MAX
+};
+
+#define IFLA_IPVLAN_MAX (__IFLA_IPVLAN_MAX - 1)
+
+enum ipvlan_mode {
+	IPVLAN_MODE_L2 = 0,
+	IPVLAN_MODE_L3,
+	IPVLAN_MODE_L3S,
+	IPVLAN_MODE_MAX
+};
+
+#define IPVLAN_F_PRIVATE	0x01
+#define IPVLAN_F_VEPA		0x02
+
+/* VXLAN section */
+enum {
+	IFLA_VXLAN_UNSPEC,
+	IFLA_VXLAN_ID,
+	IFLA_VXLAN_GROUP,	/* group or remote address */
+	IFLA_VXLAN_LINK,
+	IFLA_VXLAN_LOCAL,
+	IFLA_VXLAN_TTL,
+	IFLA_VXLAN_TOS,
+	IFLA_VXLAN_LEARNING,
+	IFLA_VXLAN_AGEING,
+	IFLA_VXLAN_LIMIT,
+	IFLA_VXLAN_PORT_RANGE,	/* source port */
+	IFLA_VXLAN_PROXY,
+	IFLA_VXLAN_RSC,
+	IFLA_VXLAN_L2MISS,
+	IFLA_VXLAN_L3MISS,
+	IFLA_VXLAN_PORT,	/* destination port */
+	IFLA_VXLAN_GROUP6,
+	IFLA_VXLAN_LOCAL6,
+	IFLA_VXLAN_UDP_CSUM,
+	IFLA_VXLAN_UDP_ZERO_CSUM6_TX,
+	IFLA_VXLAN_UDP_ZERO_CSUM6_RX,
+	IFLA_VXLAN_REMCSUM_TX,
+	IFLA_VXLAN_REMCSUM_RX,
+	IFLA_VXLAN_GBP,
+	IFLA_VXLAN_REMCSUM_NOPARTIAL,
+	IFLA_VXLAN_COLLECT_METADATA,
+	IFLA_VXLAN_LABEL,
+	IFLA_VXLAN_GPE,
+	IFLA_VXLAN_TTL_INHERIT,
+	IFLA_VXLAN_DF,
+	__IFLA_VXLAN_MAX
+};
+#define IFLA_VXLAN_MAX	(__IFLA_VXLAN_MAX - 1)
+
+struct ifla_vxlan_port_range {
+	__be16	low;
+	__be16	high;
+};
+
+enum ifla_vxlan_df {
+	VXLAN_DF_UNSET = 0,
+	VXLAN_DF_SET,
+	VXLAN_DF_INHERIT,
+	__VXLAN_DF_END,
+	VXLAN_DF_MAX = __VXLAN_DF_END - 1,
+};
+
+/* GENEVE section */
+enum {
+	IFLA_GENEVE_UNSPEC,
+	IFLA_GENEVE_ID,
+	IFLA_GENEVE_REMOTE,
+	IFLA_GENEVE_TTL,
+	IFLA_GENEVE_TOS,
+	IFLA_GENEVE_PORT,	/* destination port */
+	IFLA_GENEVE_COLLECT_METADATA,
+	IFLA_GENEVE_REMOTE6,
+	IFLA_GENEVE_UDP_CSUM,
+	IFLA_GENEVE_UDP_ZERO_CSUM6_TX,
+	IFLA_GENEVE_UDP_ZERO_CSUM6_RX,
+	IFLA_GENEVE_LABEL,
+	IFLA_GENEVE_TTL_INHERIT,
+	IFLA_GENEVE_DF,
+	__IFLA_GENEVE_MAX
+};
+#define IFLA_GENEVE_MAX	(__IFLA_GENEVE_MAX - 1)
+
+enum ifla_geneve_df {
+	GENEVE_DF_UNSET = 0,
+	GENEVE_DF_SET,
+	GENEVE_DF_INHERIT,
+	__GENEVE_DF_END,
+	GENEVE_DF_MAX = __GENEVE_DF_END - 1,
+};
+
+/* PPP section */
+enum {
+	IFLA_PPP_UNSPEC,
+	IFLA_PPP_DEV_FD,
+	__IFLA_PPP_MAX
+};
+#define IFLA_PPP_MAX (__IFLA_PPP_MAX - 1)
+
+/* GTP section */
+
+enum ifla_gtp_role {
+	GTP_ROLE_GGSN = 0,
+	GTP_ROLE_SGSN,
+};
+
+enum {
+	IFLA_GTP_UNSPEC,
+	IFLA_GTP_FD0,
+	IFLA_GTP_FD1,
+	IFLA_GTP_PDP_HASHSIZE,
+	IFLA_GTP_ROLE,
+	__IFLA_GTP_MAX,
+};
+#define IFLA_GTP_MAX (__IFLA_GTP_MAX - 1)
+
+/* Bonding section */
+
+enum {
+	IFLA_BOND_UNSPEC,
+	IFLA_BOND_MODE,
+	IFLA_BOND_ACTIVE_SLAVE,
+	IFLA_BOND_MIIMON,
+	IFLA_BOND_UPDELAY,
+	IFLA_BOND_DOWNDELAY,
+	IFLA_BOND_USE_CARRIER,
+	IFLA_BOND_ARP_INTERVAL,
+	IFLA_BOND_ARP_IP_TARGET,
+	IFLA_BOND_ARP_VALIDATE,
+	IFLA_BOND_ARP_ALL_TARGETS,
+	IFLA_BOND_PRIMARY,
+	IFLA_BOND_PRIMARY_RESELECT,
+	IFLA_BOND_FAIL_OVER_MAC,
+	IFLA_BOND_XMIT_HASH_POLICY,
+	IFLA_BOND_RESEND_IGMP,
+	IFLA_BOND_NUM_PEER_NOTIF,
+	IFLA_BOND_ALL_SLAVES_ACTIVE,
+	IFLA_BOND_MIN_LINKS,
+	IFLA_BOND_LP_INTERVAL,
+	IFLA_BOND_PACKETS_PER_SLAVE,
+	IFLA_BOND_AD_LACP_RATE,
+	IFLA_BOND_AD_SELECT,
+	IFLA_BOND_AD_INFO,
+	IFLA_BOND_AD_ACTOR_SYS_PRIO,
+	IFLA_BOND_AD_USER_PORT_KEY,
+	IFLA_BOND_AD_ACTOR_SYSTEM,
+	IFLA_BOND_TLB_DYNAMIC_LB,
+	__IFLA_BOND_MAX,
+};
+
+#define IFLA_BOND_MAX	(__IFLA_BOND_MAX - 1)
+
+enum {
+	IFLA_BOND_AD_INFO_UNSPEC,
+	IFLA_BOND_AD_INFO_AGGREGATOR,
+	IFLA_BOND_AD_INFO_NUM_PORTS,
+	IFLA_BOND_AD_INFO_ACTOR_KEY,
+	IFLA_BOND_AD_INFO_PARTNER_KEY,
+	IFLA_BOND_AD_INFO_PARTNER_MAC,
+	__IFLA_BOND_AD_INFO_MAX,
+};
+
+#define IFLA_BOND_AD_INFO_MAX	(__IFLA_BOND_AD_INFO_MAX - 1)
+
+enum {
+	IFLA_BOND_SLAVE_UNSPEC,
+	IFLA_BOND_SLAVE_STATE,
+	IFLA_BOND_SLAVE_MII_STATUS,
+	IFLA_BOND_SLAVE_LINK_FAILURE_COUNT,
+	IFLA_BOND_SLAVE_PERM_HWADDR,
+	IFLA_BOND_SLAVE_QUEUE_ID,
+	IFLA_BOND_SLAVE_AD_AGGREGATOR_ID,
+	IFLA_BOND_SLAVE_AD_ACTOR_OPER_PORT_STATE,
+	IFLA_BOND_SLAVE_AD_PARTNER_OPER_PORT_STATE,
+	__IFLA_BOND_SLAVE_MAX,
+};
+
+#define IFLA_BOND_SLAVE_MAX	(__IFLA_BOND_SLAVE_MAX - 1)
+
+/* SR-IOV virtual function management section */
+
+enum {
+	IFLA_VF_INFO_UNSPEC,
+	IFLA_VF_INFO,
+	__IFLA_VF_INFO_MAX,
+};
+
+#define IFLA_VF_INFO_MAX (__IFLA_VF_INFO_MAX - 1)
+
+enum {
+	IFLA_VF_UNSPEC,
+	IFLA_VF_MAC,		/* Hardware queue specific attributes */
+	IFLA_VF_VLAN,		/* VLAN ID and QoS */
+	IFLA_VF_TX_RATE,	/* Max TX Bandwidth Allocation */
+	IFLA_VF_SPOOFCHK,	/* Spoof Checking on/off switch */
+	IFLA_VF_LINK_STATE,	/* link state enable/disable/auto switch */
+	IFLA_VF_RATE,		/* Min and Max TX Bandwidth Allocation */
+	IFLA_VF_RSS_QUERY_EN,	/* RSS Redirection Table and Hash Key query
+				 * on/off switch
+				 */
+	IFLA_VF_STATS,		/* network device statistics */
+	IFLA_VF_TRUST,		/* Trust VF */
+	IFLA_VF_IB_NODE_GUID,	/* VF Infiniband node GUID */
+	IFLA_VF_IB_PORT_GUID,	/* VF Infiniband port GUID */
+	IFLA_VF_VLAN_LIST,	/* nested list of vlans, option for QinQ */
+	__IFLA_VF_MAX,
+};
+
+#define IFLA_VF_MAX (__IFLA_VF_MAX - 1)
+
+struct ifla_vf_mac {
+	__u32 vf;
+	__u8 mac[32]; /* MAX_ADDR_LEN */
+};
+
+struct ifla_vf_vlan {
+	__u32 vf;
+	__u32 vlan; /* 0 - 4095, 0 disables VLAN filter */
+	__u32 qos;
+};
+
+enum {
+	IFLA_VF_VLAN_INFO_UNSPEC,
+	IFLA_VF_VLAN_INFO,	/* VLAN ID, QoS and VLAN protocol */
+	__IFLA_VF_VLAN_INFO_MAX,
+};
+
+#define IFLA_VF_VLAN_INFO_MAX (__IFLA_VF_VLAN_INFO_MAX - 1)
+#define MAX_VLAN_LIST_LEN 1
+
+struct ifla_vf_vlan_info {
+	__u32 vf;
+	__u32 vlan; /* 0 - 4095, 0 disables VLAN filter */
+	__u32 qos;
+	__be16 vlan_proto; /* VLAN protocol either 802.1Q or 802.1ad */
+};
+
+struct ifla_vf_tx_rate {
+	__u32 vf;
+	__u32 rate; /* Max TX bandwidth in Mbps, 0 disables throttling */
+};
+
+struct ifla_vf_rate {
+	__u32 vf;
+	__u32 min_tx_rate; /* Min Bandwidth in Mbps */
+	__u32 max_tx_rate; /* Max Bandwidth in Mbps */
+};
+
+struct ifla_vf_spoofchk {
+	__u32 vf;
+	__u32 setting;
+};
+
+struct ifla_vf_guid {
+	__u32 vf;
+	__u64 guid;
+};
+
+enum {
+	IFLA_VF_LINK_STATE_AUTO,	/* link state of the uplink */
+	IFLA_VF_LINK_STATE_ENABLE,	/* link always up */
+	IFLA_VF_LINK_STATE_DISABLE,	/* link always down */
+	__IFLA_VF_LINK_STATE_MAX,
+};
+
+struct ifla_vf_link_state {
+	__u32 vf;
+	__u32 link_state;
+};
+
+struct ifla_vf_rss_query_en {
+	__u32 vf;
+	__u32 setting;
+};
+
+enum {
+	IFLA_VF_STATS_RX_PACKETS,
+	IFLA_VF_STATS_TX_PACKETS,
+	IFLA_VF_STATS_RX_BYTES,
+	IFLA_VF_STATS_TX_BYTES,
+	IFLA_VF_STATS_BROADCAST,
+	IFLA_VF_STATS_MULTICAST,
+	IFLA_VF_STATS_PAD,
+	IFLA_VF_STATS_RX_DROPPED,
+	IFLA_VF_STATS_TX_DROPPED,
+	__IFLA_VF_STATS_MAX,
+};
+
+#define IFLA_VF_STATS_MAX (__IFLA_VF_STATS_MAX - 1)
+
+struct ifla_vf_trust {
+	__u32 vf;
+	__u32 setting;
+};
+
+/* VF ports management section
+ *
+ *	Nested layout of set/get msg is:
+ *
+ *		[IFLA_NUM_VF]
+ *		[IFLA_VF_PORTS]
+ *			[IFLA_VF_PORT]
+ *				[IFLA_PORT_*], ...
+ *			[IFLA_VF_PORT]
+ *				[IFLA_PORT_*], ...
+ *			...
+ *		[IFLA_PORT_SELF]
+ *			[IFLA_PORT_*], ...
+ */
+
+enum {
+	IFLA_VF_PORT_UNSPEC,
+	IFLA_VF_PORT,			/* nest */
+	__IFLA_VF_PORT_MAX,
+};
+
+#define IFLA_VF_PORT_MAX (__IFLA_VF_PORT_MAX - 1)
+
+enum {
+	IFLA_PORT_UNSPEC,
+	IFLA_PORT_VF,			/* __u32 */
+	IFLA_PORT_PROFILE,		/* string */
+	IFLA_PORT_VSI_TYPE,		/* 802.1Qbg (pre-)standard VDP */
+	IFLA_PORT_INSTANCE_UUID,	/* binary UUID */
+	IFLA_PORT_HOST_UUID,		/* binary UUID */
+	IFLA_PORT_REQUEST,		/* __u8 */
+	IFLA_PORT_RESPONSE,		/* __u16, output only */
+	__IFLA_PORT_MAX,
+};
+
+#define IFLA_PORT_MAX (__IFLA_PORT_MAX - 1)
+
+#define PORT_PROFILE_MAX	40
+#define PORT_UUID_MAX		16
+#define PORT_SELF_VF		-1
+
+enum {
+	PORT_REQUEST_PREASSOCIATE = 0,
+	PORT_REQUEST_PREASSOCIATE_RR,
+	PORT_REQUEST_ASSOCIATE,
+	PORT_REQUEST_DISASSOCIATE,
+};
+
+enum {
+	PORT_VDP_RESPONSE_SUCCESS = 0,
+	PORT_VDP_RESPONSE_INVALID_FORMAT,
+	PORT_VDP_RESPONSE_INSUFFICIENT_RESOURCES,
+	PORT_VDP_RESPONSE_UNUSED_VTID,
+	PORT_VDP_RESPONSE_VTID_VIOLATION,
+	PORT_VDP_RESPONSE_VTID_VERSION_VIOALTION,
+	PORT_VDP_RESPONSE_OUT_OF_SYNC,
+	/* 0x08-0xFF reserved for future VDP use */
+	PORT_PROFILE_RESPONSE_SUCCESS = 0x100,
+	PORT_PROFILE_RESPONSE_INPROGRESS,
+	PORT_PROFILE_RESPONSE_INVALID,
+	PORT_PROFILE_RESPONSE_BADSTATE,
+	PORT_PROFILE_RESPONSE_INSUFFICIENT_RESOURCES,
+	PORT_PROFILE_RESPONSE_ERROR,
+};
+
+struct ifla_port_vsi {
+	__u8 vsi_mgr_id;
+	__u8 vsi_type_id[3];
+	__u8 vsi_type_version;
+	__u8 pad[3];
+};
+
+
+/* IPoIB section */
+
+enum {
+	IFLA_IPOIB_UNSPEC,
+	IFLA_IPOIB_PKEY,
+	IFLA_IPOIB_MODE,
+	IFLA_IPOIB_UMCAST,
+	__IFLA_IPOIB_MAX
+};
+
+enum {
+	IPOIB_MODE_DATAGRAM  = 0, /* using unreliable datagram QPs */
+	IPOIB_MODE_CONNECTED = 1, /* using connected QPs */
+};
+
+#define IFLA_IPOIB_MAX (__IFLA_IPOIB_MAX - 1)
+
+
+/* HSR section */
+
+enum {
+	IFLA_HSR_UNSPEC,
+	IFLA_HSR_SLAVE1,
+	IFLA_HSR_SLAVE2,
+	IFLA_HSR_MULTICAST_SPEC,	/* Last byte of supervision addr */
+	IFLA_HSR_SUPERVISION_ADDR,	/* Supervision frame multicast addr */
+	IFLA_HSR_SEQ_NR,
+	IFLA_HSR_VERSION,		/* HSR version */
+	__IFLA_HSR_MAX,
+};
+
+#define IFLA_HSR_MAX (__IFLA_HSR_MAX - 1)
+
+/* STATS section */
+
+struct if_stats_msg {
+	__u8  family;
+	__u8  pad1;
+	__u16 pad2;
+	__u32 ifindex;
+	__u32 filter_mask;
+};
+
+/* A stats attribute can be netdev specific or a global stat.
+ * For netdev stats, lets use the prefix IFLA_STATS_LINK_*
+ */
+enum {
+	IFLA_STATS_UNSPEC, /* also used as 64bit pad attribute */
+	IFLA_STATS_LINK_64,
+	IFLA_STATS_LINK_XSTATS,
+	IFLA_STATS_LINK_XSTATS_SLAVE,
+	IFLA_STATS_LINK_OFFLOAD_XSTATS,
+	IFLA_STATS_AF_SPEC,
+	__IFLA_STATS_MAX,
+};
+
+#define IFLA_STATS_MAX (__IFLA_STATS_MAX - 1)
+
+#define IFLA_STATS_FILTER_BIT(ATTR)	(1 << (ATTR - 1))
+
+/* These are embedded into IFLA_STATS_LINK_XSTATS:
+ * [IFLA_STATS_LINK_XSTATS]
+ * -> [LINK_XSTATS_TYPE_xxx]
+ *    -> [rtnl link type specific attributes]
+ */
+enum {
+	LINK_XSTATS_TYPE_UNSPEC,
+	LINK_XSTATS_TYPE_BRIDGE,
+	LINK_XSTATS_TYPE_BOND,
+	__LINK_XSTATS_TYPE_MAX
+};
+#define LINK_XSTATS_TYPE_MAX (__LINK_XSTATS_TYPE_MAX - 1)
+
+/* These are stats embedded into IFLA_STATS_LINK_OFFLOAD_XSTATS */
+enum {
+	IFLA_OFFLOAD_XSTATS_UNSPEC,
+	IFLA_OFFLOAD_XSTATS_CPU_HIT, /* struct rtnl_link_stats64 */
+	__IFLA_OFFLOAD_XSTATS_MAX
+};
+#define IFLA_OFFLOAD_XSTATS_MAX (__IFLA_OFFLOAD_XSTATS_MAX - 1)
+
+/* XDP section */
+
+#define XDP_FLAGS_UPDATE_IF_NOEXIST	(1U << 0)
+#define XDP_FLAGS_SKB_MODE		(1U << 1)
+#define XDP_FLAGS_DRV_MODE		(1U << 2)
+#define XDP_FLAGS_HW_MODE		(1U << 3)
+#define XDP_FLAGS_MODES			(XDP_FLAGS_SKB_MODE | \
+					 XDP_FLAGS_DRV_MODE | \
+					 XDP_FLAGS_HW_MODE)
+#define XDP_FLAGS_MASK			(XDP_FLAGS_UPDATE_IF_NOEXIST | \
+					 XDP_FLAGS_MODES)
+
+/* These are stored into IFLA_XDP_ATTACHED on dump. */
+enum {
+	XDP_ATTACHED_NONE = 0,
+	XDP_ATTACHED_DRV,
+	XDP_ATTACHED_SKB,
+	XDP_ATTACHED_HW,
+	XDP_ATTACHED_MULTI,
+};
+
+enum {
+	IFLA_XDP_UNSPEC,
+	IFLA_XDP_FD,
+	IFLA_XDP_ATTACHED,
+	IFLA_XDP_FLAGS,
+	IFLA_XDP_PROG_ID,
+	IFLA_XDP_DRV_PROG_ID,
+	IFLA_XDP_SKB_PROG_ID,
+	IFLA_XDP_HW_PROG_ID,
+	__IFLA_XDP_MAX,
+};
+
+#define IFLA_XDP_MAX (__IFLA_XDP_MAX - 1)
+
+enum {
+	IFLA_EVENT_NONE,
+	IFLA_EVENT_REBOOT,		/* internal reset / reboot */
+	IFLA_EVENT_FEATURES,		/* change in offload features */
+	IFLA_EVENT_BONDING_FAILOVER,	/* change in active slave */
+	IFLA_EVENT_NOTIFY_PEERS,	/* re-sent grat. arp/ndisc */
+	IFLA_EVENT_IGMP_RESEND,		/* re-sent IGMP JOIN */
+	IFLA_EVENT_BONDING_OPTIONS,	/* change in bonding options */
+};
+
+/* tun section */
+
+enum {
+	IFLA_TUN_UNSPEC,
+	IFLA_TUN_OWNER,
+	IFLA_TUN_GROUP,
+	IFLA_TUN_TYPE,
+	IFLA_TUN_PI,
+	IFLA_TUN_VNET_HDR,
+	IFLA_TUN_PERSIST,
+	IFLA_TUN_MULTI_QUEUE,
+	IFLA_TUN_NUM_QUEUES,
+	IFLA_TUN_NUM_DISABLED_QUEUES,
+	__IFLA_TUN_MAX,
+};
+
+#define IFLA_TUN_MAX (__IFLA_TUN_MAX - 1)
+
+/* rmnet section */
+
+#define RMNET_FLAGS_INGRESS_DEAGGREGATION         (1U << 0)
+#define RMNET_FLAGS_INGRESS_MAP_COMMANDS          (1U << 1)
+#define RMNET_FLAGS_INGRESS_MAP_CKSUMV4           (1U << 2)
+#define RMNET_FLAGS_EGRESS_MAP_CKSUMV4            (1U << 3)
+
+enum {
+	IFLA_RMNET_UNSPEC,
+	IFLA_RMNET_MUX_ID,
+	IFLA_RMNET_FLAGS,
+	__IFLA_RMNET_MAX,
+};
+
+#define IFLA_RMNET_MAX	(__IFLA_RMNET_MAX - 1)
+
+struct ifla_rmnet_flags {
+	__u32	flags;
+	__u32	mask;
+};
+
+#endif /* _UAPI_LINUX_IF_LINK_H */
diff --git a/src/xdp/include/linux/if_xdp.h b/src/xdp/include/linux/if_xdp.h
new file mode 100644
index 000000000..be328c593
--- /dev/null
+++ b/src/xdp/include/linux/if_xdp.h
@@ -0,0 +1,108 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * if_xdp: XDP socket user-space interface
+ * Copyright(c) 2018 Intel Corporation.
+ *
+ * Author(s): Björn Töpel <bjorn.topel@intel.com>
+ *	      Magnus Karlsson <magnus.karlsson@intel.com>
+ */
+
+#ifndef _LINUX_IF_XDP_H
+#define _LINUX_IF_XDP_H
+
+#include <linux/types.h>
+
+/* Options for the sxdp_flags field */
+#define XDP_SHARED_UMEM	(1 << 0)
+#define XDP_COPY	(1 << 1) /* Force copy-mode */
+#define XDP_ZEROCOPY	(1 << 2) /* Force zero-copy mode */
+/* If this option is set, the driver might go sleep and in that case
+ * the XDP_RING_NEED_WAKEUP flag in the fill and/or Tx rings will be
+ * set. If it is set, the application need to explicitly wake up the
+ * driver with a poll() (Rx and Tx) or sendto() (Tx only). If you are
+ * running the driver and the application on the same core, you should
+ * use this option so that the kernel will yield to the user space
+ * application.
+ */
+#define XDP_USE_NEED_WAKEUP (1 << 3)
+
+/* Flags for xsk_umem_config flags */
+#define XDP_UMEM_UNALIGNED_CHUNK_FLAG (1 << 0)
+
+struct sockaddr_xdp {
+	__u16 sxdp_family;
+	__u16 sxdp_flags;
+	__u32 sxdp_ifindex;
+	__u32 sxdp_queue_id;
+	__u32 sxdp_shared_umem_fd;
+};
+
+/* XDP_RING flags */
+#define XDP_RING_NEED_WAKEUP (1 << 0)
+
+struct xdp_ring_offset {
+	__u64 producer;
+	__u64 consumer;
+	__u64 desc;
+	__u64 flags;
+};
+
+struct xdp_mmap_offsets {
+	struct xdp_ring_offset rx;
+	struct xdp_ring_offset tx;
+	struct xdp_ring_offset fr; /* Fill */
+	struct xdp_ring_offset cr; /* Completion */
+};
+
+/* XDP socket options */
+#define XDP_MMAP_OFFSETS		1
+#define XDP_RX_RING			2
+#define XDP_TX_RING			3
+#define XDP_UMEM_REG			4
+#define XDP_UMEM_FILL_RING		5
+#define XDP_UMEM_COMPLETION_RING	6
+#define XDP_STATISTICS			7
+#define XDP_OPTIONS			8
+
+struct xdp_umem_reg {
+	__u64 addr; /* Start of packet data area */
+	__u64 len; /* Length of packet data area */
+	__u32 chunk_size;
+	__u32 headroom;
+	__u32 flags;
+};
+
+struct xdp_statistics {
+	__u64 rx_dropped; /* Dropped for reasons other than invalid desc */
+	__u64 rx_invalid_descs; /* Dropped due to invalid descriptor */
+	__u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
+};
+
+struct xdp_options {
+	__u32 flags;
+};
+
+/* Flags for the flags field of struct xdp_options */
+#define XDP_OPTIONS_ZEROCOPY (1 << 0)
+
+/* Pgoff for mmaping the rings */
+#define XDP_PGOFF_RX_RING			  0
+#define XDP_PGOFF_TX_RING		 0x80000000
+#define XDP_UMEM_PGOFF_FILL_RING	0x100000000ULL
+#define XDP_UMEM_PGOFF_COMPLETION_RING	0x180000000ULL
+
+/* Masks for unaligned chunks mode */
+#define XSK_UNALIGNED_BUF_OFFSET_SHIFT 48
+#define XSK_UNALIGNED_BUF_ADDR_MASK \
+	((1ULL << XSK_UNALIGNED_BUF_OFFSET_SHIFT) - 1)
+
+/* Rx/Tx descriptor */
+struct xdp_desc {
+	__u64 addr;
+	__u32 len;
+	__u32 options;
+};
+
+/* UMEM descriptor is __u64 */
+
+#endif /* _LINUX_IF_XDP_H */
diff --git a/src/xdp/include/perf-sys.h b/src/xdp/include/perf-sys.h
new file mode 100644
index 000000000..2fd16e482
--- /dev/null
+++ b/src/xdp/include/perf-sys.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copied from $(LINUX)/tools/perf/perf-sys.h (kernel 4.18) */
+#ifndef _PERF_SYS_H
+#define _PERF_SYS_H
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <linux/types.h>
+#include <linux/perf_event.h>
+/*
+ * remove the following headers to allow for userspace program compilation
+ * #include <linux/compiler.h>
+ * #include <asm/barrier.h>
+ */
+#ifdef __powerpc__
+#define CPUINFO_PROC	{"cpu"}
+#endif
+
+#ifdef __s390__
+#define CPUINFO_PROC	{"vendor_id"}
+#endif
+
+#ifdef __sh__
+#define CPUINFO_PROC	{"cpu type"}
+#endif
+
+#ifdef __hppa__
+#define CPUINFO_PROC	{"cpu"}
+#endif
+
+#ifdef __sparc__
+#define CPUINFO_PROC	{"cpu"}
+#endif
+
+#ifdef __alpha__
+#define CPUINFO_PROC	{"cpu model"}
+#endif
+
+#ifdef __arm__
+#define CPUINFO_PROC	{"model name", "Processor"}
+#endif
+
+#ifdef __mips__
+#define CPUINFO_PROC	{"cpu model"}
+#endif
+
+#ifdef __arc__
+#define CPUINFO_PROC	{"Processor"}
+#endif
+
+#ifdef __xtensa__
+#define CPUINFO_PROC	{"core ID"}
+#endif
+
+#ifndef CPUINFO_PROC
+#define CPUINFO_PROC	{ "model name", }
+#endif
+
+static inline int
+sys_perf_event_open(struct perf_event_attr *attr,
+		      pid_t pid, int cpu, int group_fd,
+		      unsigned long flags)
+{
+	int fd;
+
+	fd = syscall(__NR_perf_event_open, attr, pid, cpu,
+		     group_fd, flags);
+
+#ifdef HAVE_ATTR_TEST
+	if (unlikely(test_attr__enabled))
+		test_attr__open(attr, pid, cpu, fd, group_fd, flags);
+#endif
+	return fd;
+}
+
+#endif /* _PERF_SYS_H */
diff --git a/src/xdp/utils/Makefile b/src/xdp/utils/Makefile
new file mode 100644
index 000000000..42d6e63e3
--- /dev/null
+++ b/src/xdp/utils/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+
+USER_TARGETS := xdp_stats xdp_loader
+
+LIBBPF_DIR = ../libbpf/src/
+COMMON_DIR = ../common/
+
+# Extend with another COMMON_OBJS
+COMMON_OBJS += $(COMMON_DIR)/common_libbpf.o
+
+include $(COMMON_DIR)/common.mk
diff --git a/src/xdp/utils/xdp_loader b/src/xdp/utils/xdp_loader
new file mode 100755
index 000000000..887a7788b
--- /dev/null
+++ b/src/xdp/utils/xdp_loader
diff --git a/src/xdp/utils/xdp_loader.c b/src/xdp/utils/xdp_loader.c
new file mode 100644
index 000000000..d3b05d0c0
--- /dev/null
+++ b/src/xdp/utils/xdp_loader.c
@@ -0,0 +1,165 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+static const char *__doc__ = "XDP loader\n"
+	" - Allows selecting BPF section --progsec name to XDP-attach to --dev\n";
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <getopt.h>
+
+#include <locale.h>
+#include <unistd.h>
+#include <time.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include <net/if.h>
+#include <linux/if_link.h> /* depend on kernel-headers installed */
+
+#include "../common/common_params.h"
+#include "../common/common_user_bpf_xdp.h"
+#include "../common/common_libbpf.h"
+
+static const char *default_filename = "xdp_prog_kern.o";
+
+static const struct option_wrapper long_options[] = {
+
+	{{"help",        no_argument,		NULL, 'h' },
+	 "Show help", false},
+
+	{{"dev",         required_argument,	NULL, 'd' },
+	 "Operate on device <ifname>", "<ifname>", true},
+
+	{{"skb-mode",    no_argument,		NULL, 'S' },
+	 "Install XDP program in SKB (AKA generic) mode"},
+
+	{{"native-mode", no_argument,		NULL, 'N' },
+	 "Install XDP program in native mode"},
+
+	{{"auto-mode",   no_argument,		NULL, 'A' },
+	 "Auto-detect SKB or native mode"},
+
+	{{"force",       no_argument,		NULL, 'F' },
+	 "Force install, replacing existing program on interface"},
+
+	{{"unload",      no_argument,		NULL, 'U' },
+	 "Unload XDP program instead of loading"},
+
+	{{"reuse-maps",  no_argument,		NULL, 'M' },
+	 "Reuse pinned maps"},
+
+	{{"quiet",       no_argument,		NULL, 'q' },
+	 "Quiet mode (no output)"},
+
+	{{"filename",    required_argument,	NULL,  1  },
+	 "Load program from <file>", "<file>"},
+
+	{{"progsec",    required_argument,	NULL,  2  },
+	 "Load program in <section> of the ELF file", "<section>"},
+
+	{{0, 0, NULL,  0 }, NULL, false}
+};
+
+#ifndef PATH_MAX
+#define PATH_MAX	4096
+#endif
+
+const char *pin_basedir =  "/sys/fs/bpf";
+const char *map_name    =  "xdp_stats_map";
+
+/* Pinning maps under /sys/fs/bpf in subdir */
+int pin_maps_in_bpf_object(struct bpf_object *bpf_obj, struct config *cfg)
+{
+	char map_filename[PATH_MAX];
+	int err, len;
+
+	len = snprintf(map_filename, PATH_MAX, "%s/%s/%s",
+		       pin_basedir, cfg->ifname, map_name);
+	if (len < 0) {
+		fprintf(stderr, "ERR: creating map_name\n");
+		return EXIT_FAIL_OPTION;
+	}
+
+	/* Existing/previous XDP prog might not have cleaned up */
+	if (access(map_filename, F_OK ) != -1 ) {
+		if (verbose)
+			printf(" - Unpinning (remove) prev maps in %s/\n",
+			       cfg->pin_dir);
+
+		/* Basically calls unlink(3) on map_filename */
+		err = bpf_object__unpin_maps(bpf_obj, cfg->pin_dir);
+		if (err) {
+			fprintf(stderr, "ERR: UNpinning maps in %s\n", cfg->pin_dir);
+			return EXIT_FAIL_BPF;
+		}
+	}
+	if (verbose)
+		printf(" - Pinning maps in %s/\n", cfg->pin_dir);
+
+	/* This will pin all maps in our bpf_object */
+	err = bpf_object__pin_maps(bpf_obj, cfg->pin_dir);
+	if (err)
+		return EXIT_FAIL_BPF;
+
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_object *bpf_obj;
+	int err, len;
+
+	struct config cfg = {
+		.xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST | XDP_FLAGS_DRV_MODE,
+		.ifindex   = -1,
+		.do_unload = false,
+	};
+	/* Set default BPF-ELF object file and BPF program name */
+	strncpy(cfg.filename, default_filename, sizeof(cfg.filename));
+	/* Cmdline options can change progsec */
+	parse_cmdline_args(argc, argv, long_options, &cfg, __doc__);
+
+	/* Required option */
+	if (cfg.ifindex == -1) {
+		fprintf(stderr, "ERR: required option --dev missing\n\n");
+		usage(argv[0], __doc__, long_options, (argc == 1));
+		return EXIT_FAIL_OPTION;
+	}
+	if (cfg.do_unload) {
+		if (!cfg.reuse_maps) {
+		/* TODO: Miss unpin of maps on unload */
+		}
+		return xdp_link_detach(cfg.ifindex, cfg.xdp_flags, 0);
+	}
+
+	len = snprintf(cfg.pin_dir, PATH_MAX, "%s/%s", pin_basedir, cfg.ifname);
+	if (len < 0) {
+		fprintf(stderr, "ERR: creating pin dirname\n");
+		return EXIT_FAIL_OPTION;
+	}
+
+
+	bpf_obj = load_bpf_and_xdp_attach(&cfg);
+	if (!bpf_obj)
+		return EXIT_FAIL_BPF;
+
+	if (verbose) {
+		printf("Success: Loaded BPF-object(%s) and used section(%s)\n",
+		       cfg.filename, cfg.progsec);
+		printf(" - XDP prog attached on device:%s(ifindex:%d)\n",
+		       cfg.ifname, cfg.ifindex);
+	}
+
+	/* Use the --dev name as subdir for exporting/pinning maps */
+	if (!cfg.reuse_maps) {
+		err = pin_maps_in_bpf_object(bpf_obj, &cfg);
+		if (err) {
+			fprintf(stderr, "ERR: pinning maps\n");
+			return err;
+		}
+	}
+
+	return EXIT_OK;
+}
diff --git a/src/xdp/utils/xdp_stats b/src/xdp/utils/xdp_stats
new file mode 100755
index 000000000..fafb10cd1
--- /dev/null
+++ b/src/xdp/utils/xdp_stats
diff --git a/src/xdp/utils/xdp_stats.c b/src/xdp/utils/xdp_stats.c
new file mode 100644
index 000000000..5dbec8351
--- /dev/null
+++ b/src/xdp/utils/xdp_stats.c
@@ -0,0 +1,295 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+static const char *__doc__ = "XDP stats program\n"
+	" - Finding xdp_stats_map via --dev name info\n";
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <getopt.h>
+
+#include <locale.h>
+#include <unistd.h>
+#include <time.h>
+
+#include <bpf/bpf.h>
+/* Lesson#1: this prog does not need to #include <bpf/libbpf.h> as it only uses
+ * the simple bpf-syscall wrappers, defined in libbpf #include<bpf/bpf.h>
+ */
+
+#include <net/if.h>
+#include <linux/if_link.h> /* depend on kernel-headers installed */
+
+#include "../common/common_params.h"
+#include "../common/common_user_bpf_xdp.h"
+#include "../common/xdp_stats_kern_user.h"
+
+#include "../include/bpf_util.h" /* bpf_num_possible_cpus */
+
+static const struct option_wrapper long_options[] = {
+	{{"help",        no_argument,		NULL, 'h' },
+	 "Show help", false},
+
+	{{"dev",         required_argument,	NULL, 'd' },
+	 "Operate on device <ifname>", "<ifname>", true},
+
+	{{"quiet",       no_argument,		NULL, 'q' },
+	 "Quiet mode (no output)"},
+
+	{{0, 0, NULL,  0 }}
+};
+
+#define NANOSEC_PER_SEC 1000000000 /* 10^9 */
+static __u64 gettime(void)
+{
+	struct timespec t;
+	int res;
+
+	res = clock_gettime(CLOCK_MONOTONIC, &t);
+	if (res < 0) {
+		fprintf(stderr, "Error with gettimeofday! (%i)\n", res);
+		exit(EXIT_FAIL);
+	}
+	return (__u64) t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec;
+}
+
+struct record {
+	__u64 timestamp;
+	struct datarec total; /* defined in common_kern_user.h */
+};
+
+struct stats_record {
+	struct record stats[XDP_ACTION_MAX];
+};
+
+static double calc_period(struct record *r, struct record *p)
+{
+	double period_ = 0;
+	__u64 period = 0;
+
+	period = r->timestamp - p->timestamp;
+	if (period > 0)
+		period_ = ((double) period / NANOSEC_PER_SEC);
+
+	return period_;
+}
+
+static void stats_print_header()
+{
+	/* Print stats "header" */
+	printf("%-12s\n", "XDP-action");
+}
+
+static void stats_print(struct stats_record *stats_rec,
+			struct stats_record *stats_prev)
+{
+	struct record *rec, *prev;
+	__u64 packets, bytes;
+	double period;
+	double pps; /* packets per sec */
+	double bps; /* bits per sec */
+	int i;
+
+	stats_print_header(); /* Print stats "header" */
+
+	/* Print for each XDP actions stats */
+	for (i = 0; i < XDP_ACTION_MAX; i++)
+	{
+		char *fmt = "%-12s %'11lld pkts (%'10.0f pps)"
+			" %'11lld Kbytes (%'6.0f Mbits/s)"
+			" period:%f\n";
+		const char *action = action2str(i);
+
+		rec  = &stats_rec->stats[i];
+		prev = &stats_prev->stats[i];
+
+		period = calc_period(rec, prev);
+		if (period == 0)
+		       return;
+
+		packets = rec->total.rx_packets - prev->total.rx_packets;
+		pps     = packets / period;
+
+		bytes   = rec->total.rx_bytes   - prev->total.rx_bytes;
+		bps     = (bytes * 8)/ period / 1000000;
+
+		printf(fmt, action, rec->total.rx_packets, pps,
+		       rec->total.rx_bytes / 1000 , bps,
+		       period);
+	}
+	printf("\n");
+}
+
+
+/* BPF_MAP_TYPE_ARRAY */
+void map_get_value_array(int fd, __u32 key, struct datarec *value)
+{
+	if ((bpf_map_lookup_elem(fd, &key, value)) != 0) {
+		fprintf(stderr,
+			"ERR: bpf_map_lookup_elem failed key:0x%X\n", key);
+	}
+}
+
+/* BPF_MAP_TYPE_PERCPU_ARRAY */
+void map_get_value_percpu_array(int fd, __u32 key, struct datarec *value)
+{
+	/* For percpu maps, userspace gets a value per possible CPU */
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	struct datarec values[nr_cpus];
+	__u64 sum_bytes = 0;
+	__u64 sum_pkts = 0;
+	int i;
+
+	if ((bpf_map_lookup_elem(fd, &key, values)) != 0) {
+		fprintf(stderr,
+			"ERR: bpf_map_lookup_elem failed key:0x%X\n", key);
+		return;
+	}
+
+	/* Sum values from each CPU */
+	for (i = 0; i < nr_cpus; i++) {
+		sum_pkts  += values[i].rx_packets;
+		sum_bytes += values[i].rx_bytes;
+	}
+	value->rx_packets = sum_pkts;
+	value->rx_bytes   = sum_bytes;
+}
+
+static bool map_collect(int fd, __u32 map_type, __u32 key, struct record *rec)
+{
+	struct datarec value;
+
+	/* Get time as close as possible to reading map contents */
+	rec->timestamp = gettime();
+
+	switch (map_type) {
+	case BPF_MAP_TYPE_ARRAY:
+		map_get_value_array(fd, key, &value);
+		break;
+	case BPF_MAP_TYPE_PERCPU_ARRAY:
+		map_get_value_percpu_array(fd, key, &value);
+		break;
+	default:
+		fprintf(stderr, "ERR: Unknown map_type(%u) cannot handle\n",
+			map_type);
+		return false;
+		break;
+	}
+
+	rec->total.rx_packets = value.rx_packets;
+	rec->total.rx_bytes   = value.rx_bytes;
+	return true;
+}
+
+static void stats_collect(int map_fd, __u32 map_type,
+			  struct stats_record *stats_rec)
+{
+	/* Collect all XDP actions stats  */
+	__u32 key;
+
+	for (key = 0; key < XDP_ACTION_MAX; key++) {
+		map_collect(map_fd, map_type, key, &stats_rec->stats[key]);
+	}
+}
+
+static int stats_poll(const char *pin_dir, int map_fd, __u32 id,
+		      __u32 map_type, int interval)
+{
+	struct bpf_map_info info = {};
+	struct stats_record prev, record = { 0 };
+
+	/* Trick to pretty printf with thousands separators use %' */
+	setlocale(LC_NUMERIC, "en_US");
+
+	/* Get initial reading quickly */
+	stats_collect(map_fd, map_type, &record);
+	usleep(1000000/4);
+
+	while (1) {
+		prev = record; /* struct copy */
+
+		map_fd = open_bpf_map_file(pin_dir, "xdp_stats_map", &info);
+		if (map_fd < 0) {
+			return EXIT_FAIL_BPF;
+		} else if (id != info.id) {
+			printf("BPF map xdp_stats_map changed its ID, restarting\n");
+			return 0;
+		}
+
+		stats_collect(map_fd, map_type, &record);
+		stats_print(&record, &prev);
+		sleep(interval);
+	}
+
+	return 0;
+}
+
+#ifndef PATH_MAX
+#define PATH_MAX	4096
+#endif
+
+const char *pin_basedir =  "/sys/fs/bpf";
+
+int main(int argc, char **argv)
+{
+	const struct bpf_map_info map_expect = {
+		.key_size    = sizeof(__u32),
+		.value_size  = sizeof(struct datarec),
+		.max_entries = XDP_ACTION_MAX,
+	};
+	struct bpf_map_info info = { 0 };
+	char pin_dir[PATH_MAX];
+	int stats_map_fd;
+	int interval = 2;
+	int len, err;
+
+	struct config cfg = {
+		.ifindex   = -1,
+		.do_unload = false,
+	};
+
+	/* Cmdline options can change progsec */
+	parse_cmdline_args(argc, argv, long_options, &cfg, __doc__);
+
+	/* Required option */
+	if (cfg.ifindex == -1) {
+		fprintf(stderr, "ERR: required option --dev missing\n\n");
+		usage(argv[0], __doc__, long_options, (argc == 1));
+		return EXIT_FAIL_OPTION;
+	}
+
+	/* Use the --dev name as subdir for finding pinned maps */
+	len = snprintf(pin_dir, PATH_MAX, "%s/%s", pin_basedir, cfg.ifname);
+	if (len < 0) {
+		fprintf(stderr, "ERR: creating pin dirname\n");
+		return EXIT_FAIL_OPTION;
+	}
+
+	for ( ;; ) {
+		stats_map_fd = open_bpf_map_file(pin_dir, "xdp_stats_map", &info);
+		if (stats_map_fd < 0) {
+			return EXIT_FAIL_BPF;
+		}
+
+		/* check map info, e.g. datarec is expected size */
+		err = check_map_fd_info(&info, &map_expect);
+		if (err) {
+			fprintf(stderr, "ERR: map via FD not compatible\n");
+			return err;
+		}
+		if (verbose) {
+			printf("\nCollecting stats from BPF map\n");
+			printf(" - BPF map (bpf_map_type:%d) id:%d name:%s"
+			       " key_size:%d value_size:%d max_entries:%d\n",
+			       info.type, info.id, info.name,
+			       info.key_size, info.value_size, info.max_entries
+			       );
+		}
+
+		err = stats_poll(pin_dir, stats_map_fd, info.id, info.type, interval);
+		if (err < 0)
+			return err;
+	}
+
+	return EXIT_OK;
+}
diff --git a/src/xdp/xdp_prog_kern.c b/src/xdp/xdp_prog_kern.c
new file mode 100644
index 000000000..a1eb395af
--- /dev/null
+++ b/src/xdp/xdp_prog_kern.c
@@ -0,0 +1,343 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/bpf.h>
+#include <linux/in.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+// The parsing helper functions from the packet01 lesson have moved here
+#include "common/parsing_helpers.h"
+#include "common/rewrite_helpers.h"
+
+/* Defines xdp_stats_map */
+#include "common/xdp_stats_kern_user.h"
+#include "common/xdp_stats_kern.h"
+
+#ifndef memcpy
+#define memcpy(dest, src, n) __builtin_memcpy((dest), (src), (n))
+#endif
+
+struct bpf_map_def SEC("maps") tx_port = {
+	.type = BPF_MAP_TYPE_DEVMAP,
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.max_entries = 256,
+};
+
+struct bpf_map_def SEC("maps") redirect_params = {
+	.type = BPF_MAP_TYPE_HASH,
+	.key_size = ETH_ALEN,
+	.value_size = ETH_ALEN,
+	.max_entries = 1,
+};
+
+static __always_inline __u16 csum_fold_helper(__u32 csum)
+{
+	return ~((csum & 0xffff) + (csum >> 16));
+}
+
+/*
+ * The icmp_checksum_diff function takes pointers to old and new structures and
+ * the old checksum and returns the new checksum.  It uses the bpf_csum_diff
+ * helper to compute the checksum difference. Note that the sizes passed to the
+ * bpf_csum_diff helper should be multiples of 4, as it operates on 32-bit
+ * words.
+ */
+static __always_inline __u16 icmp_checksum_diff(
+		__u16 seed,
+		struct icmphdr_common *icmphdr_new,
+		struct icmphdr_common *icmphdr_old)
+{
+	__u32 csum, size = sizeof(struct icmphdr_common);
+
+	csum = bpf_csum_diff((__be32 *)icmphdr_old, size, (__be32 *)icmphdr_new, size, seed);
+	return csum_fold_helper(csum);
+}
+
+/* Solution to packet03/assignment-1 */
+SEC("xdp_icmp_echo")
+int xdp_icmp_echo_func(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct hdr_cursor nh;
+	struct ethhdr *eth;
+	int eth_type;
+	int ip_type;
+	int icmp_type;
+	struct iphdr *iphdr;
+	struct ipv6hdr *ipv6hdr;
+	__u16 echo_reply, old_csum;
+	struct icmphdr_common *icmphdr;
+	struct icmphdr_common icmphdr_old;
+	__u32 action = XDP_PASS;
+
+	/* These keep track of the next header type and iterator pointer */
+	nh.pos = data;
+
+	/* Parse Ethernet and IP/IPv6 headers */
+	eth_type = parse_ethhdr(&nh, data_end, &eth);
+	if (eth_type == bpf_htons(ETH_P_IP)) {
+		ip_type = parse_iphdr(&nh, data_end, &iphdr);
+		if (ip_type != IPPROTO_ICMP)
+			goto out;
+	} else if (eth_type == bpf_htons(ETH_P_IPV6)) {
+		ip_type = parse_ip6hdr(&nh, data_end, &ipv6hdr);
+		if (ip_type != IPPROTO_ICMPV6)
+			goto out;
+	} else {
+		goto out;
+	}
+
+	/*
+	 * We are using a special parser here which returns a stucture
+	 * containing the "protocol-independent" part of an ICMP or ICMPv6
+	 * header.  For purposes of this Assignment we are not interested in
+	 * the rest of the structure.
+	 */
+	icmp_type = parse_icmphdr_common(&nh, data_end, &icmphdr);
+	if (eth_type == bpf_htons(ETH_P_IP) && icmp_type == ICMP_ECHO) {
+		/* Swap IP source and destination */
+		swap_src_dst_ipv4(iphdr);
+		echo_reply = ICMP_ECHOREPLY;
+	} else if (eth_type == bpf_htons(ETH_P_IPV6)
+		   && icmp_type == ICMPV6_ECHO_REQUEST) {
+		/* Swap IPv6 source and destination */
+		swap_src_dst_ipv6(ipv6hdr);
+		echo_reply = ICMPV6_ECHO_REPLY;
+	} else {
+		goto out;
+	}
+
+	/* Swap Ethernet source and destination */
+	swap_src_dst_mac(eth);
+
+
+	/* Patch the packet and update the checksum.*/
+	old_csum = icmphdr->cksum;
+	icmphdr->cksum = 0;
+	icmphdr_old = *icmphdr;
+	icmphdr->type = echo_reply;
+	icmphdr->cksum = icmp_checksum_diff(~old_csum, icmphdr, &icmphdr_old);
+
+	/* Another, less generic, but a bit more efficient way to update the
+	 * checksum is listed below.  As only one 16-bit word changed, the sum
+	 * can be patched using this formula: sum' = ~(~sum + ~m0 + m1), where
+	 * sum' is a new sum, sum is an old sum, m0 and m1 are the old and new
+	 * 16-bit words, correspondingly. In the formula above the + operation
+	 * is defined as the following function:
+	 *
+	 *     static __always_inline __u16 csum16_add(__u16 csum, __u16 addend)
+	 *     {
+	 *         csum += addend;
+	 *         return csum + (csum < addend);
+	 *     }
+	 *
+	 * So an alternative code to update the checksum might look like this:
+	 *
+	 *     __u16 m0 = * (__u16 *) icmphdr;
+	 *     icmphdr->type = echo_reply;
+	 *     __u16 m1 = * (__u16 *) icmphdr;
+	 *     icmphdr->checksum = ~(csum16_add(csum16_add(~icmphdr->checksum, ~m0), m1));
+	 */
+
+	action = XDP_TX;
+
+out:
+	return xdp_stats_record_action(ctx, action);
+}
+
+/* Solution to packet03/assignment-2 */
+SEC("xdp_redirect")
+int xdp_redirect_func(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct hdr_cursor nh;
+	struct ethhdr *eth;
+	int eth_type;
+	int action = XDP_PASS;
+	unsigned char dst[ETH_ALEN] = { /* TODO: put your values here */ };
+	unsigned ifindex = 0/* TODO: put your values here */;
+
+	/* These keep track of the next header type and iterator pointer */
+	nh.pos = data;
+
+	/* Parse Ethernet and IP/IPv6 headers */
+	eth_type = parse_ethhdr(&nh, data_end, &eth);
+	if (eth_type == -1)
+		goto out;
+
+	/* Set a proper destination address */
+	memcpy(eth->h_dest, dst, ETH_ALEN);
+	action = bpf_redirect(ifindex, 0);
+
+out:
+	return xdp_stats_record_action(ctx, action);
+}
+
+/* Solution to packet03/assignment-3 */
+SEC("xdp_redirect_map")
+int xdp_redirect_map_func(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct hdr_cursor nh;
+	struct ethhdr *eth;
+	int eth_type;
+	int action = XDP_PASS;
+	unsigned char *dst;
+
+	/* These keep track of the next header type and iterator pointer */
+	nh.pos = data;
+
+	/* Parse Ethernet and IP/IPv6 headers */
+	eth_type = parse_ethhdr(&nh, data_end, &eth);
+	if (eth_type == -1)
+		goto out;
+
+	/* Do we know where to redirect this packet? */
+	dst = bpf_map_lookup_elem(&redirect_params, eth->h_source);
+	if (!dst)
+		goto out;
+
+	/* Set a proper destination address */
+	memcpy(eth->h_dest, dst, ETH_ALEN);
+	action = bpf_redirect_map(&tx_port, 0, 0);
+
+out:
+	return xdp_stats_record_action(ctx, action);
+}
+
+#define AF_INET 2
+#define AF_INET6 10
+#define IPV6_FLOWINFO_MASK bpf_htonl(0x0FFFFFFF)
+
+/* from include/net/ip.h */
+static __always_inline int ip_decrease_ttl(struct iphdr *iph)
+{
+	__u32 check = iph->check;
+	check += bpf_htons(0x0100);
+	iph->check = (__u16)(check + (check >= 0xFFFF));
+	return --iph->ttl;
+}
+
+/* Solution to packet03/assignment-4 */
+/* xdp_router is the name of the xdp program */
+SEC("xdp_router")
+int xdp_router_func(struct xdp_md *ctx)
+{
+	/* this is the packet context*/
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct bpf_fib_lookup fib_params = {};
+	struct ethhdr *eth = data;
+	struct ipv6hdr *ip6h;
+	struct iphdr *iph;
+	__u16 h_proto;
+	__u64 nh_off;
+	int rc;
+	/* default action is to pass */
+	int action = XDP_PASS;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end) {
+		action = XDP_DROP;
+		goto out;
+	}
+
+	/* determine if this is IP4 or IPv6 by looking at the Ethernet protocol field */
+	h_proto = eth->h_proto;
+	if (h_proto == bpf_htons(ETH_P_IP)) {
+		/* IPv4 part of the code */
+		iph = data + nh_off;
+
+		if (iph + 1 > data_end) {
+			action = XDP_DROP;
+			goto out;
+		}
+		/* as a real router, we need to check the TTL to prevent never ending loops*/
+		if (iph->ttl <= 1)
+			goto out;
+
+		/* populate the fib_params fields to prepare for the lookup */
+		fib_params.family	= AF_INET;
+		fib_params.tos		= iph->tos;
+		fib_params.l4_protocol	= iph->protocol;
+		fib_params.sport	= 0;
+		fib_params.dport	= 0;
+		fib_params.tot_len	= bpf_ntohs(iph->tot_len);
+		fib_params.ipv4_src	= iph->saddr;
+		fib_params.ipv4_dst	= iph->daddr;
+	} else if (h_proto == bpf_htons(ETH_P_IPV6)) {
+		/* IPv6 part of the code */
+		struct in6_addr *src = (struct in6_addr *) fib_params.ipv6_src;
+		struct in6_addr *dst = (struct in6_addr *) fib_params.ipv6_dst;
+
+		ip6h = data + nh_off;
+		if (ip6h + 1 > data_end) {
+			action = XDP_DROP;
+			goto out;
+		}
+		/* as a real router, we need to check the TTL to prevent never ending loops*/
+		if (ip6h->hop_limit <= 1)
+			goto out;
+
+		/* populate the fib_params fields to prepare for the lookup */
+		fib_params.family	= AF_INET6;
+		fib_params.flowinfo	= *(__be32 *) ip6h & IPV6_FLOWINFO_MASK;
+		fib_params.l4_protocol	= ip6h->nexthdr;
+		fib_params.sport	= 0;
+		fib_params.dport	= 0;
+		fib_params.tot_len	= bpf_ntohs(ip6h->payload_len);
+		*src			= ip6h->saddr;
+		*dst			= ip6h->daddr;
+	} else {
+		goto out;
+	}
+
+	fib_params.ifindex = ctx->ingress_ifindex;
+
+	/* this is where the FIB lookup happens. If the lookup is successful */
+	/* it will populate the fib_params.ifindex with the egress interface index */
+
+	rc = bpf_fib_lookup(ctx, &fib_params, sizeof(fib_params), 0);
+	switch (rc) {
+	case BPF_FIB_LKUP_RET_SUCCESS:         /* lookup successful */
+		   /* we are a router, so we need to decrease the ttl */
+		if (h_proto == bpf_htons(ETH_P_IP))
+			ip_decrease_ttl(iph);
+		else if (h_proto == bpf_htons(ETH_P_IPV6))
+			ip6h->hop_limit--;
+		/* set the correct new source and destionation mac addresses */
+		/* can be found in fib_params.dmac and fib_params.smac */
+		memcpy(eth->h_dest, fib_params.dmac, ETH_ALEN);
+		memcpy(eth->h_source, fib_params.smac, ETH_ALEN);
+		/* and done, now we set the action to bpf_redirect_map with fib_params.ifindex which is the egress port as paramater */
+		action = bpf_redirect_map(&tx_port, fib_params.ifindex, 0);
+		break;
+	case BPF_FIB_LKUP_RET_BLACKHOLE:    /* dest is blackholed; can be dropped */
+	case BPF_FIB_LKUP_RET_UNREACHABLE:  /* dest is unreachable; can be dropped */
+	case BPF_FIB_LKUP_RET_PROHIBIT:     /* dest not allowed; can be dropped */
+		action = XDP_DROP;
+		break;
+	case BPF_FIB_LKUP_RET_NOT_FWDED:    /* packet is not forwarded */
+	case BPF_FIB_LKUP_RET_FWD_DISABLED: /* fwding is not enabled on ingress */
+	case BPF_FIB_LKUP_RET_UNSUPP_LWT:   /* fwd requires encapsulation */
+	case BPF_FIB_LKUP_RET_NO_NEIGH:     /* no neighbor entry for nh */
+	case BPF_FIB_LKUP_RET_FRAG_NEEDED:  /* fragmentation required to fwd */
+		/* PASS */
+		break;
+	}
+
+out:
+	/* and done, update stats and return action */
+	return xdp_stats_record_action(ctx, action);
+}
+
+SEC("xdp_pass")
+int xdp_pass_func(struct xdp_md *ctx)
+{
+	return xdp_stats_record_action(ctx, XDP_PASS);
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/src/xdp/xdp_prog_user.c b/src/xdp/xdp_prog_user.c
new file mode 100644
index 000000000..d91610791
--- /dev/null
+++ b/src/xdp/xdp_prog_user.c
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+static const char *__doc__ = "XDP redirect helper\n"
+	" - Allows to populate/query tx_port and redirect_params maps\n";
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <getopt.h>
+#include <stdbool.h>
+
+#include <locale.h>
+#include <unistd.h>
+#include <time.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include <net/if.h>
+#include <linux/if_ether.h>
+#include <linux/if_link.h> /* depend on kernel-headers installed */
+
+#include "common/common_params.h"
+#include "common/common_user_bpf_xdp.h"
+#include "common/common_libbpf.h"
+
+#include "common/xdp_stats_kern_user.h"
+
+static const struct option_wrapper long_options[] = {
+
+	{{"help",        no_argument,		NULL, 'h' },
+	 "Show help", false},
+
+	{{"dev",         required_argument,	NULL, 'd' },
+	 "Operate on device <ifname>", "<ifname>", true},
+
+	{{"redirect-dev",         required_argument,	NULL, 'r' },
+	 "Redirect to device <ifname>", "<ifname>", true},
+
+	{{"src-mac", required_argument, NULL, 'L' },
+	 "Source MAC address of <dev>", "<mac>", true },
+
+	{{"dest-mac", required_argument, NULL, 'R' },
+	 "Destination MAC address of <redirect-dev>", "<mac>", true },
+
+	{{"quiet",       no_argument,		NULL, 'q' },
+	 "Quiet mode (no output)"},
+
+	{{0, 0, NULL,  0 }, NULL, false}
+};
+
+static int parse_mac(char *str, unsigned char mac[ETH_ALEN])
+{
+	/* Assignment 3: parse a MAC address in this function and place the
+	 * result in the mac array */
+
+	return 0;
+}
+
+static int write_iface_params(int map_fd, unsigned char *src, unsigned char *dest)
+{
+	if (bpf_map_update_elem(map_fd, src, dest, 0) < 0) {
+		fprintf(stderr,
+			"WARN: Failed to update bpf map file: err(%d):%s\n",
+			errno, strerror(errno));
+		return -1;
+	}
+
+	printf("forward: %02x:%02x:%02x:%02x:%02x:%02x -> %02x:%02x:%02x:%02x:%02x:%02x\n",
+			src[0], src[1], src[2], src[3], src[4], src[5],
+			dest[0], dest[1], dest[2], dest[3], dest[4], dest[5]
+	      );
+
+	return 0;
+}
+
+#ifndef PATH_MAX
+#define PATH_MAX 4096
+#endif
+
+const char *pin_basedir =  "/sys/fs/bpf";
+
+int main(int argc, char **argv)
+{
+	int i;
+	int len;
+	int map_fd;
+	bool redirect_map;
+	char pin_dir[PATH_MAX];
+	unsigned char src[ETH_ALEN];
+	unsigned char dest[ETH_ALEN];
+
+	struct config cfg = {
+		.ifindex   = -1,
+		.redirect_ifindex   = -1,
+	};
+
+	/* Cmdline options can change progsec */
+	parse_cmdline_args(argc, argv, long_options, &cfg, __doc__);
+
+	redirect_map = (cfg.ifindex > 0) && (cfg.redirect_ifindex > 0);
+
+	if (cfg.redirect_ifindex > 0 && cfg.ifindex == -1) {
+		fprintf(stderr, "ERR: required option --dev missing\n\n");
+		usage(argv[0], __doc__, long_options, (argc == 1));
+		return EXIT_FAIL_OPTION;
+	}
+
+	len = snprintf(pin_dir, PATH_MAX, "%s/%s", pin_basedir, cfg.ifname);
+	if (len < 0) {
+		fprintf(stderr, "ERR: creating pin dirname\n");
+		return EXIT_FAIL_OPTION;
+	}
+
+	if (parse_mac(cfg.src_mac, src) < 0) {
+		fprintf(stderr, "ERR: can't parse mac address %s\n", cfg.src_mac);
+		return EXIT_FAIL_OPTION;
+	}
+
+	if (parse_mac(cfg.dest_mac, dest) < 0) {
+		fprintf(stderr, "ERR: can't parse mac address %s\n", cfg.dest_mac);
+		return EXIT_FAIL_OPTION;
+	}
+
+
+	/* Assignment 3: open the tx_port map corresponding to the cfg.ifname interface */
+	map_fd = -1;
+
+	printf("map dir: %s\n", pin_dir);
+
+	if (redirect_map) {
+		/* setup a virtual port for the static redirect */
+		i = 0;
+		bpf_map_update_elem(map_fd, &i, &cfg.redirect_ifindex, 0);
+		printf("redirect from ifnum=%d to ifnum=%d\n", cfg.ifindex, cfg.redirect_ifindex);
+
+		/* Assignment 3: open the redirect_params map corresponding to the cfg.ifname interface */
+		map_fd = -1;
+
+		/* Setup the mapping containing MAC addresses */
+		if (write_iface_params(map_fd, src, dest) < 0) {
+			fprintf(stderr, "can't write iface params\n");
+			return 1;
+		}
+	} else {
+		/* Assignment 4: setup 1-1 mapping for the dynamic router */
+	}
+
+	return EXIT_OK;
+}