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