1
2
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.h"
19#include "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
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 xdp_flags |= XDP_FLAGS_DRV_MODE;
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 (optind == argc) {
113 usage(basename(argv[0]));
114 return 1;
115 }
116
117 if (setrlimit(RLIMIT_MEMLOCK, &r)) {
118 perror("setrlimit(RLIMIT_MEMLOCK)");
119 return 1;
120 }
121
122 ifindex = if_nametoindex(argv[optind]);
123 if (!ifindex) {
124 perror("if_nametoindex");
125 return 1;
126 }
127
128 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
129 prog_load_attr.file = filename;
130
131 if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
132 return 1;
133
134 map = bpf_map__next(NULL, obj);
135 if (!map) {
136 printf("finding a map in obj file failed\n");
137 return 1;
138 }
139 map_fd = bpf_map__fd(map);
140
141 if (!prog_fd) {
142 printf("load_bpf_file: %s\n", strerror(errno));
143 return 1;
144 }
145
146 signal(SIGINT, int_exit);
147 signal(SIGTERM, int_exit);
148
149 if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
150 printf("link set xdp fd failed\n");
151 return 1;
152 }
153
154 err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
155 if (err) {
156 printf("can't get prog info - %s\n", strerror(errno));
157 return err;
158 }
159 prog_id = info.id;
160
161 poll_stats(map_fd, 2);
162
163 return 0;
164}
165
