forked from Minki/linux
fe616055f7
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>
137 lines
2.7 KiB
C
137 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2017-18 David Ahern <dsahern@gmail.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include <linux/bpf.h>
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#include <linux/if_link.h>
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#include <linux/limits.h>
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#include <net/if.h>
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#include <errno.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdbool.h>
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#include <string.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <libgen.h>
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#include "bpf_load.h"
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#include "bpf_util.h"
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#include "libbpf.h"
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static int do_attach(int idx, int fd, const char *name)
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{
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int err;
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err = bpf_set_link_xdp_fd(idx, fd, 0);
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if (err < 0)
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printf("ERROR: failed to attach program to %s\n", name);
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return err;
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}
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static int do_detach(int idx, const char *name)
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{
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int err;
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err = bpf_set_link_xdp_fd(idx, -1, 0);
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if (err < 0)
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printf("ERROR: failed to detach program from %s\n", name);
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return err;
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}
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static void usage(const char *prog)
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{
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fprintf(stderr,
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"usage: %s [OPTS] interface-list\n"
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"\nOPTS:\n"
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" -d detach program\n"
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" -D direct table lookups (skip fib rules)\n",
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prog);
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}
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int main(int argc, char **argv)
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{
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char filename[PATH_MAX];
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int opt, i, idx, err;
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int prog_id = 0;
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int attach = 1;
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int ret = 0;
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while ((opt = getopt(argc, argv, ":dD")) != -1) {
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switch (opt) {
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case 'd':
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attach = 0;
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break;
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case 'D':
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prog_id = 1;
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break;
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default:
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usage(basename(argv[0]));
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return 1;
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}
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}
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if (optind == argc) {
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usage(basename(argv[0]));
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return 1;
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}
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if (attach) {
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snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
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if (access(filename, O_RDONLY) < 0) {
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printf("error accessing file %s: %s\n",
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filename, strerror(errno));
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return 1;
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}
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if (load_bpf_file(filename)) {
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printf("%s", bpf_log_buf);
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return 1;
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}
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if (!prog_fd[prog_id]) {
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printf("load_bpf_file: %s\n", strerror(errno));
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return 1;
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}
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}
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if (attach) {
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for (i = 1; i < 64; ++i)
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bpf_map_update_elem(map_fd[0], &i, &i, 0);
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}
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for (i = optind; i < argc; ++i) {
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idx = if_nametoindex(argv[i]);
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if (!idx)
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idx = strtoul(argv[i], NULL, 0);
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if (!idx) {
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fprintf(stderr, "Invalid arg\n");
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return 1;
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}
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if (!attach) {
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err = do_detach(idx, argv[i]);
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if (err)
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ret = err;
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} else {
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err = do_attach(idx, prog_fd[prog_id], argv[i]);
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if (err)
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ret = err;
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}
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}
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return ret;
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}
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