diff options
author | David Ahern <dsahern@gmail.com> | 2018-05-10 06:34:27 +0300 |
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committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-05-11 01:10:57 +0300 |
commit | fe616055f78457a0b78e0d3693d1ae26f2d7dab3 (patch) | |
tree | 2bab4dd9bff8b85508549c97886d92d82d7c22e1 /samples/bpf/xdp_fwd_user.c | |
parent | 87f5fc7e48dd3175b30dd03b41564e1a8e136323 (diff) | |
download | linux-fe616055f78457a0b78e0d3693d1ae26f2d7dab3.tar.xz |
samples/bpf: Add example of ipv4 and ipv6 forwarding in XDP
Simple example of fast-path forwarding. It has a serious flaw
in not verifying the egress device index supports XDP forwarding.
If the egress device does not packets are dropped.
Take this only as a simple example of fast-path forwarding.
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'samples/bpf/xdp_fwd_user.c')
-rw-r--r-- | samples/bpf/xdp_fwd_user.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c new file mode 100644 index 000000000000..9c6606f57126 --- /dev/null +++ b/samples/bpf/xdp_fwd_user.c @@ -0,0 +1,136 @@ +// 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_load.h" +#include "bpf_util.h" +#include "libbpf.h" + + +static int do_attach(int idx, int fd, const char *name) +{ + int err; + + err = bpf_set_link_xdp_fd(idx, fd, 0); + if (err < 0) + printf("ERROR: failed to attach program to %s\n", name); + + return err; +} + +static int do_detach(int idx, const char *name) +{ + int err; + + err = bpf_set_link_xdp_fd(idx, -1, 0); + if (err < 0) + printf("ERROR: failed to detach program from %s\n", name); + + return err; +} + +static void usage(const char *prog) +{ + fprintf(stderr, + "usage: %s [OPTS] interface-list\n" + "\nOPTS:\n" + " -d detach program\n" + " -D direct table lookups (skip fib rules)\n", + prog); +} + +int main(int argc, char **argv) +{ + char filename[PATH_MAX]; + int opt, i, idx, err; + int prog_id = 0; + int attach = 1; + int ret = 0; + + while ((opt = getopt(argc, argv, ":dD")) != -1) { + switch (opt) { + case 'd': + attach = 0; + break; + case 'D': + prog_id = 1; + break; + default: + usage(basename(argv[0])); + return 1; + } + } + + 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; + } + + if (load_bpf_file(filename)) { + printf("%s", bpf_log_buf); + return 1; + } + + if (!prog_fd[prog_id]) { + printf("load_bpf_file: %s\n", strerror(errno)); + return 1; + } + } + if (attach) { + for (i = 1; i < 64; ++i) + bpf_map_update_elem(map_fd[0], &i, &i, 0); + } + + 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]); + if (err) + ret = err; + } else { + err = do_attach(idx, prog_fd[prog_id], argv[i]); + if (err) + ret = err; + } + } + + return ret; +} |