tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#include <stdio.h>
2#include <assert.h>
3#include <linux/bpf.h>
4#include "libbpf.h"
5#include "bpf_load.h"
6#include "sock_example.h"
7#include <unistd.h>
8#include <arpa/inet.h>
9#include <sys/resource.h>
10
11#define PARSE_IP 3
12#define PARSE_IP_PROG_FD (prog_fd[0])
13#define PROG_ARRAY_FD (map_fd[0])
14
15struct bpf_flow_keys {
16 __be32 src;
17 __be32 dst;
18 union {
19 __be32 ports;
20 __be16 port16[2];
21 };
22 __u32 ip_proto;
23};
24
25struct pair {
26 __u64 packets;
27 __u64 bytes;
28};
29
30int main(int argc, char **argv)
31{
32 struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
33 char filename[256];
34 FILE *f;
35 int i, sock, err, id, key = PARSE_IP;
36 struct bpf_prog_info info = {};
37 uint32_t info_len = sizeof(info);
38
39 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
40 setrlimit(RLIMIT_MEMLOCK, &r);
41
42 if (load_bpf_file(filename)) {
43 printf("%s", bpf_log_buf);
44 return 1;
45 }
46
47 /* Test fd array lookup which returns the id of the bpf_prog */
48 err = bpf_obj_get_info_by_fd(PARSE_IP_PROG_FD, &info, &info_len);
49 assert(!err);
50 err = bpf_map_lookup_elem(PROG_ARRAY_FD, &key, &id);
51 assert(!err);
52 assert(id == info.id);
53
54 sock = open_raw_sock("lo");
55
56 assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd[4],
57 sizeof(__u32)) == 0);
58
59 if (argc > 1)
60 f = popen("ping -c5 localhost", "r");
61 else
62 f = popen("netperf -l 4 localhost", "r");
63 (void) f;
64
65 for (i = 0; i < 5; i++) {
66 struct bpf_flow_keys key = {}, next_key;
67 struct pair value;
68
69 sleep(1);
70 printf("IP src.port -> dst.port bytes packets\n");
71 while (bpf_map_get_next_key(map_fd[2], &key, &next_key) == 0) {
72 bpf_map_lookup_elem(map_fd[2], &next_key, &value);
73 printf("%s.%05d -> %s.%05d %12lld %12lld\n",
74 inet_ntoa((struct in_addr){htonl(next_key.src)}),
75 next_key.port16[0],
76 inet_ntoa((struct in_addr){htonl(next_key.dst)}),
77 next_key.port16[1],
78 value.bytes, value.packets);
79 key = next_key;
80 }
81 }
82 return 0;
83}