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

14 files changed, 1428 insertions, 0 deletions

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 */