tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 bpf_prog_load_attr prog_load_attr = {
83 .prog_type = BPF_PROG_TYPE_XDP,
84 };
85 struct bpf_prog_info info = {};
86 __u32 info_len = sizeof(info);
87 const char *optstr = "FSN";
88 int prog_fd, map_fd, opt;
89 struct bpf_object *obj;
90 struct bpf_map *map;
91 char filename[256];
92 int err;
93
94 while ((opt = getopt(argc, argv, optstr)) != -1) {
95 switch (opt) {
96 case 'S':
97 xdp_flags |= XDP_FLAGS_SKB_MODE;
98 break;
99 case 'N':
100 /* default, set below */
101 break;
102 case 'F':
103 xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
104 break;
105 default:
106 usage(basename(argv[0]));
107 return 1;
108 }
109 }
110
111 if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
112 xdp_flags |= XDP_FLAGS_DRV_MODE;
113
114 if (optind == argc) {
115 usage(basename(argv[0]));
116 return 1;
117 }
118
119 ifindex = if_nametoindex(argv[optind]);
120 if (!ifindex) {
121 perror("if_nametoindex");
122 return 1;
123 }
124
125 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
126 prog_load_attr.file = filename;
127
128 if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
129 return 1;
130
131 map = bpf_map__next(NULL, obj);
132 if (!map) {
133 printf("finding a map in obj file failed\n");
134 return 1;
135 }
136 map_fd = bpf_map__fd(map);
137
138 if (!prog_fd) {
139 printf("bpf_prog_load_xattr: %s\n", strerror(errno));
140 return 1;
141 }
142
143 signal(SIGINT, int_exit);
144 signal(SIGTERM, int_exit);
145
146 if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
147 printf("link set xdp fd failed\n");
148 return 1;
149 }
150
151 err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
152 if (err) {
153 printf("can't get prog info - %s\n", strerror(errno));
154 return err;
155 }
156 prog_id = info.id;
157
158 poll_stats(map_fd, 2);
159
160 return 0;
161}