treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206
[muen/linux.git] / samples / bpf / xdp1_user.c
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
21 static int ifindex;
22 static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
23 static __u32 prog_id;
24
25 static 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  */
44 static 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
69 static 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
80 int 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 }