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Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
cf9b1199 SD |
2 | #include <stdio.h> |
3 | #include <assert.h> | |
cf9b1199 | 4 | #include <unistd.h> |
2bf3e2ef | 5 | #include <bpf/bpf.h> |
3677d0a1 | 6 | #include <bpf/libbpf.h> |
cf9b1199 | 7 | #include <sys/socket.h> |
cf9b1199 SD |
8 | #include <netinet/in.h> |
9 | #include <arpa/inet.h> | |
10 | ||
11 | int main(int ac, char **argv) | |
12 | { | |
cf9b1199 | 13 | struct sockaddr_in *serv_addr_in, *mapped_addr_in, *tmp_addr_in; |
3677d0a1 DL |
14 | struct sockaddr serv_addr, mapped_addr, tmp_addr; |
15 | int serverfd, serverconnfd, clientfd, map_fd; | |
16 | struct bpf_link *link = NULL; | |
17 | struct bpf_program *prog; | |
18 | struct bpf_object *obj; | |
19 | socklen_t sockaddr_len; | |
cf9b1199 SD |
20 | char filename[256]; |
21 | char *ip; | |
22 | ||
23 | serv_addr_in = (struct sockaddr_in *)&serv_addr; | |
24 | mapped_addr_in = (struct sockaddr_in *)&mapped_addr; | |
25 | tmp_addr_in = (struct sockaddr_in *)&tmp_addr; | |
26 | ||
27 | snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); | |
3677d0a1 DL |
28 | obj = bpf_object__open_file(filename, NULL); |
29 | if (libbpf_get_error(obj)) { | |
30 | fprintf(stderr, "ERROR: opening BPF object file failed\n"); | |
31 | return 0; | |
32 | } | |
33 | ||
34 | prog = bpf_object__find_program_by_name(obj, "bpf_prog1"); | |
35 | if (libbpf_get_error(prog)) { | |
36 | fprintf(stderr, "ERROR: finding a prog in obj file failed\n"); | |
37 | goto cleanup; | |
38 | } | |
39 | ||
40 | /* load BPF program */ | |
41 | if (bpf_object__load(obj)) { | |
42 | fprintf(stderr, "ERROR: loading BPF object file failed\n"); | |
43 | goto cleanup; | |
44 | } | |
45 | ||
46 | map_fd = bpf_object__find_map_fd_by_name(obj, "dnat_map"); | |
47 | if (map_fd < 0) { | |
48 | fprintf(stderr, "ERROR: finding a map in obj file failed\n"); | |
49 | goto cleanup; | |
50 | } | |
cf9b1199 | 51 | |
3677d0a1 DL |
52 | link = bpf_program__attach(prog); |
53 | if (libbpf_get_error(link)) { | |
54 | fprintf(stderr, "ERROR: bpf_program__attach failed\n"); | |
55 | link = NULL; | |
56 | goto cleanup; | |
cf9b1199 SD |
57 | } |
58 | ||
59 | assert((serverfd = socket(AF_INET, SOCK_STREAM, 0)) > 0); | |
60 | assert((clientfd = socket(AF_INET, SOCK_STREAM, 0)) > 0); | |
61 | ||
62 | /* Bind server to ephemeral port on lo */ | |
63 | memset(&serv_addr, 0, sizeof(serv_addr)); | |
64 | serv_addr_in->sin_family = AF_INET; | |
65 | serv_addr_in->sin_port = 0; | |
66 | serv_addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK); | |
67 | ||
68 | assert(bind(serverfd, &serv_addr, sizeof(serv_addr)) == 0); | |
69 | ||
70 | sockaddr_len = sizeof(serv_addr); | |
71 | assert(getsockname(serverfd, &serv_addr, &sockaddr_len) == 0); | |
72 | ip = inet_ntoa(serv_addr_in->sin_addr); | |
73 | printf("Server bound to: %s:%d\n", ip, ntohs(serv_addr_in->sin_port)); | |
74 | ||
75 | memset(&mapped_addr, 0, sizeof(mapped_addr)); | |
76 | mapped_addr_in->sin_family = AF_INET; | |
77 | mapped_addr_in->sin_port = htons(5555); | |
78 | mapped_addr_in->sin_addr.s_addr = inet_addr("255.255.255.255"); | |
79 | ||
3677d0a1 | 80 | assert(!bpf_map_update_elem(map_fd, &mapped_addr, &serv_addr, BPF_ANY)); |
cf9b1199 SD |
81 | |
82 | assert(listen(serverfd, 5) == 0); | |
83 | ||
84 | ip = inet_ntoa(mapped_addr_in->sin_addr); | |
85 | printf("Client connecting to: %s:%d\n", | |
86 | ip, ntohs(mapped_addr_in->sin_port)); | |
87 | assert(connect(clientfd, &mapped_addr, sizeof(mapped_addr)) == 0); | |
88 | ||
89 | sockaddr_len = sizeof(tmp_addr); | |
90 | ip = inet_ntoa(tmp_addr_in->sin_addr); | |
91 | assert((serverconnfd = accept(serverfd, &tmp_addr, &sockaddr_len)) > 0); | |
92 | printf("Server received connection from: %s:%d\n", | |
93 | ip, ntohs(tmp_addr_in->sin_port)); | |
94 | ||
95 | sockaddr_len = sizeof(tmp_addr); | |
96 | assert(getpeername(clientfd, &tmp_addr, &sockaddr_len) == 0); | |
97 | ip = inet_ntoa(tmp_addr_in->sin_addr); | |
98 | printf("Client's peer address: %s:%d\n", | |
99 | ip, ntohs(tmp_addr_in->sin_port)); | |
100 | ||
101 | /* Is the server's getsockname = the socket getpeername */ | |
102 | assert(memcmp(&serv_addr, &tmp_addr, sizeof(struct sockaddr_in)) == 0); | |
103 | ||
3677d0a1 DL |
104 | cleanup: |
105 | bpf_link__destroy(link); | |
106 | bpf_object__close(obj); | |
cf9b1199 SD |
107 | return 0; |
108 | } |