1// SPDX-License-Identifier: GPL-2.0-only
  2/* Copyright (c) 2016 PLUMgrid
  3 */
  4#include <linux/bpf.h>
  5#include <linux/if_link.h>
  6#include <assert.h>
  7#include <errno.h>
  8#include <signal.h>
  9#include <stdio.h>
 10#include <stdlib.h>
 11#include <string.h>
 12#include <unistd.h>
 13#include <libgen.h>
 14#include <sys/resource.h>
 15#include <net/if.h>
 16
 17#include "bpf_util.h"
 18#include <bpf/bpf.h>
 19#include <bpf/libbpf.h>
 20
 21static int ifindex;
 22static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 23static __u32 prog_id;
 24
 25static void int_exit(int sig)
 26{
 27	__u32 curr_prog_id = 0;
 28
 29	if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
 30		printf("bpf_get_link_xdp_id failed\n");
 31		exit(1);
 32	}
 33	if (prog_id == curr_prog_id)
 34		bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
 35	else if (!curr_prog_id)
 36		printf("couldn't find a prog id on a given interface\n");
 37	else
 38		printf("program on interface changed, not removing\n");
 39	exit(0);
 40}
 41
 42/* simple per-protocol drop counter
 43 */
 44static void poll_stats(int map_fd, int interval)
 45{
 46	unsigned int nr_cpus = bpf_num_possible_cpus();
 47	__u64 values[nr_cpus], prev[UINT8_MAX] = { 0 };
 48	int i;
 49
 50	while (1) {
 51		__u32 key = UINT32_MAX;
 52
 53		sleep(interval);
 54
 55		while (bpf_map_get_next_key(map_fd, &key, &key) != -1) {
 56			__u64 sum = 0;
 57
 58			assert(bpf_map_lookup_elem(map_fd, &key, values) == 0);
 59			for (i = 0; i < nr_cpus; i++)
 60				sum += values[i];
 61			if (sum > prev[key])
 62				printf("proto %u: %10llu pkt/s\n",
 63				       key, (sum - prev[key]) / interval);
 64			prev[key] = sum;
 65		}
 66	}
 67}
 68
 69static void usage(const char *prog)
 70{
 71	fprintf(stderr,
 72		"usage: %s [OPTS] IFACE\n\n"
 73		"OPTS:\n"
 74		"    -S    use skb-mode\n"
 75		"    -N    enforce native mode\n"
 76		"    -F    force loading prog\n",
 77		prog);
 78}
 79
 80int main(int argc, char **argv)
 81{
 82	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 83	struct bpf_prog_load_attr prog_load_attr = {
 84		.prog_type	= BPF_PROG_TYPE_XDP,
 85	};
 86	struct bpf_prog_info info = {};
 87	__u32 info_len = sizeof(info);
 88	const char *optstr = "FSN";
 89	int prog_fd, map_fd, opt;
 90	struct bpf_object *obj;
 91	struct bpf_map *map;
 92	char filename[256];
 93	int err;
 94
 95	while ((opt = getopt(argc, argv, optstr)) != -1) {
 96		switch (opt) {
 97		case 'S':
 98			xdp_flags |= XDP_FLAGS_SKB_MODE;
 99			break;
100		case 'N':
101			/* default, set below */
102			break;
103		case 'F':
104			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
105			break;
106		default:
107			usage(basename(argv[0]));
108			return 1;
109		}
110	}
111
112	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
113		xdp_flags |= XDP_FLAGS_DRV_MODE;
114
115	if (optind == argc) {
116		usage(basename(argv[0]));
117		return 1;
118	}
119
120	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
121		perror("setrlimit(RLIMIT_MEMLOCK)");
122		return 1;
123	}
124
125	ifindex = if_nametoindex(argv[optind]);
126	if (!ifindex) {
127		perror("if_nametoindex");
128		return 1;
129	}
130
131	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
132	prog_load_attr.file = filename;
133
134	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
135		return 1;
136
137	map = bpf_map__next(NULL, obj);
138	if (!map) {
139		printf("finding a map in obj file failed\n");
140		return 1;
141	}
142	map_fd = bpf_map__fd(map);
143
144	if (!prog_fd) {
145		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
146		return 1;
147	}
148
149	signal(SIGINT, int_exit);
150	signal(SIGTERM, int_exit);
151
152	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
153		printf("link set xdp fd failed\n");
154		return 1;
155	}
156
157	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
158	if (err) {
159		printf("can't get prog info - %s\n", strerror(errno));
160		return err;
161	}
162	prog_id = info.id;
163
164	poll_stats(map_fd, 2);
165
166	return 0;
167}