![Daniel T. Lee](/assets/img/avatar_default.png)
Currently, each xdp samples are inconsistent in the use. Most of the samples fetch the interface with it's name. (ex. xdp1, xdp2skb, xdp_redirect_cpu, xdp_sample_pkts, etc.) But some of the xdp samples are fetching the interface with ifindex by command argument. This commit enables xdp samples to fetch interface with it's name without changing the original index interface fetching. (<ifname|ifindex> fetching in the same way as xdp_sample_pkts_user.c does.) Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
185 lines
4.2 KiB
C
185 lines
4.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0
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* Copyright (c) 2018 Facebook
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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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#include <linux/bpf.h>
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#include <linux/if_link.h>
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#include <assert.h>
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#include <errno.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <net/if.h>
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#include <sys/resource.h>
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#include <arpa/inet.h>
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#include <netinet/ether.h>
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#include <unistd.h>
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#include <time.h>
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#include "bpf.h"
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#include "libbpf.h"
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#define STATS_INTERVAL_S 2U
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static int ifindex = -1;
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static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
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static __u32 prog_id;
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static void int_exit(int sig)
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{
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__u32 curr_prog_id = 0;
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if (ifindex > -1) {
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if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
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printf("bpf_get_link_xdp_id failed\n");
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exit(1);
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}
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if (prog_id == curr_prog_id)
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bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
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else if (!curr_prog_id)
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printf("couldn't find a prog id on a given iface\n");
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else
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printf("program on interface changed, not removing\n");
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}
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exit(0);
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}
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/* simple "icmp packet too big sent" counter
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*/
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static void poll_stats(unsigned int map_fd, unsigned int kill_after_s)
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{
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time_t started_at = time(NULL);
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__u64 value = 0;
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int key = 0;
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while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {
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sleep(STATS_INTERVAL_S);
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assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
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printf("icmp \"packet too big\" sent: %10llu pkts\n", value);
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}
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}
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static void usage(const char *cmd)
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{
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printf("Start a XDP prog which send ICMP \"packet too big\" \n"
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"messages if ingress packet is bigger then MAX_SIZE bytes\n");
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printf("Usage: %s [...]\n", cmd);
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printf(" -i <ifname|ifindex> Interface\n");
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printf(" -T <stop-after-X-seconds> Default: 0 (forever)\n");
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printf(" -S use skb-mode\n");
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printf(" -N enforce native mode\n");
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printf(" -F force loading prog\n");
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printf(" -h Display this help\n");
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}
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int main(int argc, char **argv)
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{
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struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
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struct bpf_prog_load_attr prog_load_attr = {
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.prog_type = BPF_PROG_TYPE_XDP,
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};
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unsigned char opt_flags[256] = {};
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const char *optstr = "i:T:SNFh";
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struct bpf_prog_info info = {};
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__u32 info_len = sizeof(info);
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unsigned int kill_after_s = 0;
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int i, prog_fd, map_fd, opt;
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struct bpf_object *obj;
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struct bpf_map *map;
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char filename[256];
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int err;
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for (i = 0; i < strlen(optstr); i++)
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if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
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opt_flags[(unsigned char)optstr[i]] = 1;
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while ((opt = getopt(argc, argv, optstr)) != -1) {
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switch (opt) {
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case 'i':
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ifindex = if_nametoindex(optarg);
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if (!ifindex)
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ifindex = atoi(optarg);
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break;
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case 'T':
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kill_after_s = atoi(optarg);
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break;
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case 'S':
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xdp_flags |= XDP_FLAGS_SKB_MODE;
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break;
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case 'N':
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xdp_flags |= XDP_FLAGS_DRV_MODE;
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break;
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case 'F':
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xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
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break;
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default:
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usage(argv[0]);
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return 1;
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}
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opt_flags[opt] = 0;
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}
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for (i = 0; i < strlen(optstr); i++) {
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if (opt_flags[(unsigned int)optstr[i]]) {
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fprintf(stderr, "Missing argument -%c\n", optstr[i]);
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usage(argv[0]);
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return 1;
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}
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}
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if (setrlimit(RLIMIT_MEMLOCK, &r)) {
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perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)");
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return 1;
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}
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if (!ifindex) {
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fprintf(stderr, "Invalid ifname\n");
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return 1;
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}
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snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
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prog_load_attr.file = filename;
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if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
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return 1;
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map = bpf_map__next(NULL, obj);
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if (!map) {
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printf("finding a map in obj file failed\n");
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return 1;
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}
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map_fd = bpf_map__fd(map);
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if (!prog_fd) {
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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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signal(SIGINT, int_exit);
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signal(SIGTERM, int_exit);
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if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
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printf("link set xdp fd failed\n");
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return 1;
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}
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err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
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if (err) {
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printf("can't get prog info - %s\n", strerror(errno));
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return 1;
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}
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prog_id = info.id;
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poll_stats(map_fd, kill_after_s);
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int_exit(0);
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return 0;
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}
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