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Now that we can use full powers of libbpf in BPF samples, we should perhaps make the simplest XDP programs not depend on bpf_load helpers. This way newcomers will be exposed to the recommended library from the start. Use of bpf_prog_load_xattr() will also make it trivial to later on request offload of the programs by simply adding ifindex to the xattr. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
139 lines
2.8 KiB
C
139 lines
2.8 KiB
C
/* Copyright (c) 2016 PLUMgrid
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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 <unistd.h>
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#include <libgen.h>
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#include <sys/resource.h>
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#include "bpf_util.h"
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#include "bpf/bpf.h"
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#include "bpf/libbpf.h"
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static int ifindex;
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static __u32 xdp_flags;
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static void int_exit(int sig)
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{
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bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
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exit(0);
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}
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/* simple per-protocol drop counter
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*/
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static void poll_stats(int map_fd, int interval)
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{
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unsigned int nr_cpus = bpf_num_possible_cpus();
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const unsigned int nr_keys = 256;
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__u64 values[nr_cpus], prev[nr_keys][nr_cpus];
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__u32 key;
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int i;
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memset(prev, 0, sizeof(prev));
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while (1) {
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sleep(interval);
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for (key = 0; key < nr_keys; key++) {
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__u64 sum = 0;
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assert(bpf_map_lookup_elem(map_fd, &key, values) == 0);
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for (i = 0; i < nr_cpus; i++)
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sum += (values[i] - prev[key][i]);
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if (sum)
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printf("proto %u: %10llu pkt/s\n",
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key, sum / interval);
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memcpy(prev[key], values, sizeof(values));
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}
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}
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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] IFINDEX\n\n"
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"OPTS:\n"
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" -S use skb-mode\n"
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" -N enforce native mode\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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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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const char *optstr = "SN";
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int 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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while ((opt = getopt(argc, argv, optstr)) != -1) {
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switch (opt) {
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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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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 (setrlimit(RLIMIT_MEMLOCK, &r)) {
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perror("setrlimit(RLIMIT_MEMLOCK)");
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return 1;
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}
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ifindex = strtoul(argv[optind], NULL, 0);
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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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poll_stats(map_fd, 2);
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return 0;
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}
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