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
20 static int ifindex;
21 static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
22 static __u32 prog_id;
23
int_exit(int sig)24 static 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 */
poll_stats(int map_fd,int interval)43 static 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
usage(const char * prog)68 static 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
main(int argc,char ** argv)79 int 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_prog_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 }
167