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Diffstat (limited to 'samples/bpf/xdp_fwd_user.c')
-rw-r--r--samples/bpf/xdp_fwd_user.c226
1 files changed, 226 insertions, 0 deletions
diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c
new file mode 100644
index 0000000000..193b3b79b3
--- /dev/null
+++ b/samples/bpf/xdp_fwd_user.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2017-18 David Ahern <dsahern@gmail.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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/bpf.h>
+#include <linux/if_link.h>
+#include <linux/limits.h>
+#include <net/if.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <libgen.h>
+
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+
+static int do_attach(int idx, int prog_fd, int map_fd, const char *name)
+{
+ int err;
+
+ err = bpf_xdp_attach(idx, prog_fd, xdp_flags, NULL);
+ if (err < 0) {
+ printf("ERROR: failed to attach program to %s\n", name);
+ return err;
+ }
+
+ /* Adding ifindex as a possible egress TX port */
+ err = bpf_map_update_elem(map_fd, &idx, &idx, 0);
+ if (err)
+ printf("ERROR: failed using device %s as TX-port\n", name);
+
+ return err;
+}
+
+static int do_detach(int ifindex, const char *ifname, const char *app_name)
+{
+ LIBBPF_OPTS(bpf_xdp_attach_opts, opts);
+ struct bpf_prog_info prog_info = {};
+ char prog_name[BPF_OBJ_NAME_LEN];
+ __u32 info_len, curr_prog_id;
+ int prog_fd;
+ int err = 1;
+
+ if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) {
+ printf("ERROR: bpf_xdp_query_id failed (%s)\n",
+ strerror(errno));
+ return err;
+ }
+
+ if (!curr_prog_id) {
+ printf("ERROR: flags(0x%x) xdp prog is not attached to %s\n",
+ xdp_flags, ifname);
+ return err;
+ }
+
+ info_len = sizeof(prog_info);
+ prog_fd = bpf_prog_get_fd_by_id(curr_prog_id);
+ if (prog_fd < 0) {
+ printf("ERROR: bpf_prog_get_fd_by_id failed (%s)\n",
+ strerror(errno));
+ return prog_fd;
+ }
+
+ err = bpf_prog_get_info_by_fd(prog_fd, &prog_info, &info_len);
+ if (err) {
+ printf("ERROR: bpf_prog_get_info_by_fd failed (%s)\n",
+ strerror(errno));
+ goto close_out;
+ }
+ snprintf(prog_name, sizeof(prog_name), "%s_prog", app_name);
+ prog_name[BPF_OBJ_NAME_LEN - 1] = '\0';
+
+ if (strcmp(prog_info.name, prog_name)) {
+ printf("ERROR: %s isn't attached to %s\n", app_name, ifname);
+ err = 1;
+ goto close_out;
+ }
+
+ opts.old_prog_fd = prog_fd;
+ err = bpf_xdp_detach(ifindex, xdp_flags, &opts);
+ if (err < 0)
+ printf("ERROR: failed to detach program from %s (%s)\n",
+ ifname, strerror(errno));
+ /* TODO: Remember to cleanup map, when adding use of shared map
+ * bpf_map_delete_elem((map_fd, &idx);
+ */
+close_out:
+ close(prog_fd);
+ return err;
+}
+
+static void usage(const char *prog)
+{
+ fprintf(stderr,
+ "usage: %s [OPTS] interface-list\n"
+ "\nOPTS:\n"
+ " -d detach program\n"
+ " -S use skb-mode\n"
+ " -F force loading prog\n"
+ " -D direct table lookups (skip fib rules)\n",
+ prog);
+}
+
+int main(int argc, char **argv)
+{
+ const char *prog_name = "xdp_fwd";
+ struct bpf_program *prog = NULL;
+ struct bpf_program *pos;
+ const char *sec_name;
+ int prog_fd = -1, map_fd = -1;
+ char filename[PATH_MAX];
+ struct bpf_object *obj;
+ int opt, i, idx, err;
+ int attach = 1;
+ int ret = 0;
+
+ while ((opt = getopt(argc, argv, ":dDSF")) != -1) {
+ switch (opt) {
+ case 'd':
+ attach = 0;
+ break;
+ case 'S':
+ xdp_flags |= XDP_FLAGS_SKB_MODE;
+ break;
+ case 'F':
+ xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+ break;
+ case 'D':
+ prog_name = "xdp_fwd_direct";
+ break;
+ default:
+ usage(basename(argv[0]));
+ return 1;
+ }
+ }
+
+ if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+ xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+ if (optind == argc) {
+ usage(basename(argv[0]));
+ return 1;
+ }
+
+ if (attach) {
+ snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+ if (access(filename, O_RDONLY) < 0) {
+ printf("error accessing file %s: %s\n",
+ filename, strerror(errno));
+ return 1;
+ }
+
+ obj = bpf_object__open_file(filename, NULL);
+ if (libbpf_get_error(obj))
+ return 1;
+
+ prog = bpf_object__next_program(obj, NULL);
+ bpf_program__set_type(prog, BPF_PROG_TYPE_XDP);
+
+ err = bpf_object__load(obj);
+ if (err) {
+ printf("Does kernel support devmap lookup?\n");
+ /* If not, the error message will be:
+ * "cannot pass map_type 14 into func bpf_map_lookup_elem#1"
+ */
+ return 1;
+ }
+
+ bpf_object__for_each_program(pos, obj) {
+ sec_name = bpf_program__section_name(pos);
+ if (sec_name && !strcmp(sec_name, prog_name)) {
+ prog = pos;
+ break;
+ }
+ }
+ prog_fd = bpf_program__fd(prog);
+ if (prog_fd < 0) {
+ printf("program not found: %s\n", strerror(prog_fd));
+ return 1;
+ }
+ map_fd = bpf_map__fd(bpf_object__find_map_by_name(obj,
+ "xdp_tx_ports"));
+ if (map_fd < 0) {
+ printf("map not found: %s\n", strerror(map_fd));
+ return 1;
+ }
+ }
+
+ for (i = optind; i < argc; ++i) {
+ idx = if_nametoindex(argv[i]);
+ if (!idx)
+ idx = strtoul(argv[i], NULL, 0);
+
+ if (!idx) {
+ fprintf(stderr, "Invalid arg\n");
+ return 1;
+ }
+ if (!attach) {
+ err = do_detach(idx, argv[i], prog_name);
+ if (err)
+ ret = err;
+ } else {
+ err = do_attach(idx, prog_fd, map_fd, argv[i]);
+ if (err)
+ ret = err;
+ }
+ }
+
+ return ret;
+}