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

1 files changed, 165 insertions, 0 deletions

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;
+}