Commit | Line | Data |
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51570a5a CF |
1 | /* This test is a demo of using get_socket_uid and get_socket_cookie |
2 | * helper function to do per socket based network traffic monitoring. | |
3 | * It requires iptables version higher then 1.6.1. to load pinned eBPF | |
4 | * program into the xt_bpf match. | |
5 | * | |
6 | * TEST: | |
00f660ea CF |
7 | * ./run_cookie_uid_helper_example.sh -option |
8 | * option: | |
9 | * -t: do traffic monitoring test, the program will continuously | |
10 | * print out network traffic happens after program started A sample | |
11 | * output is shown below: | |
51570a5a CF |
12 | * |
13 | * cookie: 877, uid: 0x3e8, Pakcet Count: 20, Bytes Count: 11058 | |
14 | * cookie: 132, uid: 0x0, Pakcet Count: 2, Bytes Count: 286 | |
15 | * cookie: 812, uid: 0x3e8, Pakcet Count: 3, Bytes Count: 1726 | |
16 | * cookie: 802, uid: 0x3e8, Pakcet Count: 2, Bytes Count: 104 | |
17 | * cookie: 877, uid: 0x3e8, Pakcet Count: 20, Bytes Count: 11058 | |
18 | * cookie: 831, uid: 0x3e8, Pakcet Count: 2, Bytes Count: 104 | |
19 | * cookie: 0, uid: 0x0, Pakcet Count: 6, Bytes Count: 712 | |
20 | * cookie: 880, uid: 0xfffe, Pakcet Count: 1, Bytes Count: 70 | |
21 | * | |
00f660ea CF |
22 | * -s: do getsockopt SO_COOKIE test, the program will set up a pair of |
23 | * UDP sockets and send packets between them. And read out the traffic data | |
24 | * directly from the ebpf map based on the socket cookie. | |
25 | * | |
51570a5a CF |
26 | * Clean up: if using shell script, the script file will delete the iptables |
27 | * rule and unmount the bpf program when exit. Else the iptables rule need | |
28 | * to be deleted by hand, see run_cookie_uid_helper_example.sh for detail. | |
29 | */ | |
30 | ||
31 | #define _GNU_SOURCE | |
32 | ||
33 | #define offsetof(type, member) __builtin_offsetof(type, member) | |
34 | #define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x))) | |
35 | ||
36 | #include <arpa/inet.h> | |
37 | #include <errno.h> | |
38 | #include <error.h> | |
39 | #include <limits.h> | |
40 | #include <linux/bpf.h> | |
41 | #include <linux/if_ether.h> | |
00f660ea CF |
42 | #include <net/if.h> |
43 | #include <signal.h> | |
51570a5a CF |
44 | #include <stdbool.h> |
45 | #include <stdint.h> | |
46 | #include <stdio.h> | |
47 | #include <stdlib.h> | |
48 | #include <string.h> | |
49 | #include <sys/socket.h> | |
50 | #include <sys/stat.h> | |
51 | #include <sys/types.h> | |
52 | #include <unistd.h> | |
53 | #include <bpf/bpf.h> | |
8d930450 | 54 | #include "bpf_insn.h" |
51570a5a | 55 | |
00f660ea CF |
56 | #define PORT 8888 |
57 | ||
51570a5a CF |
58 | struct stats { |
59 | uint32_t uid; | |
60 | uint64_t packets; | |
61 | uint64_t bytes; | |
62 | }; | |
63 | ||
64 | static int map_fd, prog_fd; | |
65 | ||
00f660ea CF |
66 | static bool test_finish; |
67 | ||
51570a5a CF |
68 | static void maps_create(void) |
69 | { | |
70 | map_fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(uint32_t), | |
71 | sizeof(struct stats), 100, 0); | |
72 | if (map_fd < 0) | |
73 | error(1, errno, "map create failed!\n"); | |
74 | } | |
75 | ||
76 | static void prog_load(void) | |
77 | { | |
78 | static char log_buf[1 << 16]; | |
79 | ||
80 | struct bpf_insn prog[] = { | |
81 | /* | |
82 | * Save sk_buff for future usage. value stored in R6 to R10 will | |
83 | * not be reset after a bpf helper function call. | |
84 | */ | |
85 | BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), | |
86 | /* | |
87 | * pc1: BPF_FUNC_get_socket_cookie takes one parameter, | |
88 | * R1: sk_buff | |
89 | */ | |
90 | BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, | |
91 | BPF_FUNC_get_socket_cookie), | |
92 | /* pc2-4: save &socketCookie to r7 for future usage*/ | |
93 | BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8), | |
94 | BPF_MOV64_REG(BPF_REG_7, BPF_REG_10), | |
95 | BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8), | |
96 | /* | |
97 | * pc5-8: set up the registers for BPF_FUNC_map_lookup_elem, | |
98 | * it takes two parameters (R1: map_fd, R2: &socket_cookie) | |
99 | */ | |
100 | BPF_LD_MAP_FD(BPF_REG_1, map_fd), | |
101 | BPF_MOV64_REG(BPF_REG_2, BPF_REG_7), | |
102 | BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, | |
103 | BPF_FUNC_map_lookup_elem), | |
104 | /* | |
105 | * pc9. if r0 != 0x0, go to pc+14, since we have the cookie | |
106 | * stored already | |
107 | * Otherwise do pc10-22 to setup a new data entry. | |
108 | */ | |
109 | BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 14), | |
110 | BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), | |
111 | BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, | |
112 | BPF_FUNC_get_socket_uid), | |
113 | /* | |
114 | * Place a struct stats in the R10 stack and sequentially | |
115 | * place the member value into the memory. Packets value | |
116 | * is set by directly place a IMM value 1 into the stack. | |
117 | */ | |
118 | BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, | |
eb6211d3 | 119 | -32 + (__s16)offsetof(struct stats, uid)), |
51570a5a | 120 | BPF_ST_MEM(BPF_DW, BPF_REG_10, |
eb6211d3 | 121 | -32 + (__s16)offsetof(struct stats, packets), 1), |
51570a5a CF |
122 | /* |
123 | * __sk_buff is a special struct used for eBPF program to | |
124 | * directly access some sk_buff field. | |
125 | */ | |
126 | BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6, | |
127 | offsetof(struct __sk_buff, len)), | |
128 | BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, | |
eb6211d3 | 129 | -32 + (__s16)offsetof(struct stats, bytes)), |
51570a5a CF |
130 | /* |
131 | * add new map entry using BPF_FUNC_map_update_elem, it takes | |
132 | * 4 parameters (R1: map_fd, R2: &socket_cookie, R3: &stats, | |
133 | * R4: flags) | |
134 | */ | |
135 | BPF_LD_MAP_FD(BPF_REG_1, map_fd), | |
136 | BPF_MOV64_REG(BPF_REG_2, BPF_REG_7), | |
137 | BPF_MOV64_REG(BPF_REG_3, BPF_REG_10), | |
138 | BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -32), | |
139 | BPF_MOV64_IMM(BPF_REG_4, 0), | |
140 | BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, | |
141 | BPF_FUNC_map_update_elem), | |
142 | BPF_JMP_IMM(BPF_JA, 0, 0, 5), | |
143 | /* | |
144 | * pc24-30 update the packet info to a exist data entry, it can | |
145 | * be done by directly write to pointers instead of using | |
146 | * BPF_FUNC_map_update_elem helper function | |
147 | */ | |
148 | BPF_MOV64_REG(BPF_REG_9, BPF_REG_0), | |
149 | BPF_MOV64_IMM(BPF_REG_1, 1), | |
150 | BPF_STX_XADD(BPF_DW, BPF_REG_9, BPF_REG_1, | |
151 | offsetof(struct stats, packets)), | |
152 | BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6, | |
153 | offsetof(struct __sk_buff, len)), | |
154 | BPF_STX_XADD(BPF_DW, BPF_REG_9, BPF_REG_1, | |
155 | offsetof(struct stats, bytes)), | |
156 | BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6, | |
157 | offsetof(struct __sk_buff, len)), | |
158 | BPF_EXIT_INSN(), | |
159 | }; | |
160 | prog_fd = bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER, prog, | |
161 | ARRAY_SIZE(prog), "GPL", 0, | |
162 | log_buf, sizeof(log_buf)); | |
163 | if (prog_fd < 0) | |
164 | error(1, errno, "failed to load prog\n%s\n", log_buf); | |
165 | } | |
166 | ||
167 | static void prog_attach_iptables(char *file) | |
168 | { | |
169 | int ret; | |
170 | char rules[100]; | |
171 | ||
172 | if (bpf_obj_pin(prog_fd, file)) | |
173 | error(1, errno, "bpf_obj_pin"); | |
174 | if (strlen(file) > 50) { | |
175 | printf("file path too long: %s\n", file); | |
176 | exit(1); | |
177 | } | |
00f660ea | 178 | sprintf(rules, "iptables -A OUTPUT -m bpf --object-pinned %s -j ACCEPT", |
51570a5a CF |
179 | file); |
180 | ret = system(rules); | |
181 | if (ret < 0) { | |
182 | printf("iptables rule update failed: %d/n", WEXITSTATUS(ret)); | |
183 | exit(1); | |
184 | } | |
185 | } | |
186 | ||
187 | static void print_table(void) | |
188 | { | |
189 | struct stats curEntry; | |
190 | uint32_t curN = UINT32_MAX; | |
00f660ea CF |
191 | uint32_t nextN; |
192 | int res; | |
51570a5a CF |
193 | |
194 | while (bpf_map_get_next_key(map_fd, &curN, &nextN) > -1) { | |
195 | curN = nextN; | |
196 | res = bpf_map_lookup_elem(map_fd, &curN, &curEntry); | |
197 | if (res < 0) { | |
198 | error(1, errno, "fail to get entry value of Key: %u\n", | |
199 | curN); | |
200 | } else { | |
201 | printf("cookie: %u, uid: 0x%x, Packet Count: %lu," | |
202 | " Bytes Count: %lu\n", curN, curEntry.uid, | |
203 | curEntry.packets, curEntry.bytes); | |
204 | } | |
205 | } | |
206 | } | |
207 | ||
00f660ea | 208 | static void udp_client(void) |
51570a5a | 209 | { |
00f660ea CF |
210 | struct sockaddr_in si_other = {0}; |
211 | struct sockaddr_in si_me = {0}; | |
212 | struct stats dataEntry; | |
213 | int s_rcv, s_send, i, recv_len; | |
214 | char message = 'a'; | |
215 | char buf; | |
216 | uint64_t cookie; | |
217 | int res; | |
218 | socklen_t cookie_len = sizeof(cookie); | |
219 | socklen_t slen = sizeof(si_other); | |
220 | ||
221 | s_rcv = socket(PF_INET, SOCK_DGRAM, 0); | |
222 | if (s_rcv < 0) | |
223 | error(1, errno, "rcv socket creat failed!\n"); | |
224 | si_other.sin_family = AF_INET; | |
225 | si_other.sin_port = htons(PORT); | |
226 | if (inet_aton("127.0.0.1", &si_other.sin_addr) == 0) | |
227 | error(1, errno, "inet_aton\n"); | |
228 | if (bind(s_rcv, (struct sockaddr *)&si_other, sizeof(si_other)) == -1) | |
229 | error(1, errno, "bind\n"); | |
230 | s_send = socket(PF_INET, SOCK_DGRAM, 0); | |
231 | if (s_send < 0) | |
232 | error(1, errno, "send socket creat failed!\n"); | |
233 | res = getsockopt(s_send, SOL_SOCKET, SO_COOKIE, &cookie, &cookie_len); | |
234 | if (res < 0) | |
235 | printf("get cookie failed: %s\n", strerror(errno)); | |
236 | res = bpf_map_lookup_elem(map_fd, &cookie, &dataEntry); | |
237 | if (res != -1) | |
238 | error(1, errno, "socket stat found while flow not active\n"); | |
239 | for (i = 0; i < 10; i++) { | |
240 | res = sendto(s_send, &message, sizeof(message), 0, | |
241 | (struct sockaddr *)&si_other, slen); | |
242 | if (res == -1) | |
243 | error(1, errno, "send\n"); | |
244 | if (res != sizeof(message)) | |
245 | error(1, 0, "%uB != %luB\n", res, sizeof(message)); | |
246 | recv_len = recvfrom(s_rcv, &buf, sizeof(buf), 0, | |
247 | (struct sockaddr *)&si_me, &slen); | |
248 | if (recv_len < 0) | |
20cfb7a0 | 249 | error(1, errno, "receive\n"); |
00f660ea CF |
250 | res = memcmp(&(si_other.sin_addr), &(si_me.sin_addr), |
251 | sizeof(si_me.sin_addr)); | |
252 | if (res != 0) | |
253 | error(1, EFAULT, "sender addr error: %d\n", res); | |
254 | printf("Message received: %c\n", buf); | |
255 | res = bpf_map_lookup_elem(map_fd, &cookie, &dataEntry); | |
256 | if (res < 0) | |
257 | error(1, errno, "lookup sk stat failed, cookie: %lu\n", | |
258 | cookie); | |
259 | printf("cookie: %lu, uid: 0x%x, Packet Count: %lu," | |
260 | " Bytes Count: %lu\n\n", cookie, dataEntry.uid, | |
261 | dataEntry.packets, dataEntry.bytes); | |
51570a5a | 262 | } |
00f660ea CF |
263 | close(s_send); |
264 | close(s_rcv); | |
265 | } | |
51570a5a | 266 | |
00f660ea CF |
267 | static int usage(void) |
268 | { | |
269 | printf("Usage: ./run_cookie_uid_helper_example.sh" | |
270 | " bpfObjName -option\n" | |
271 | " -t traffic monitor test\n" | |
272 | " -s getsockopt cookie test\n"); | |
273 | return 1; | |
274 | } | |
51570a5a | 275 | |
4784726f | 276 | static void finish(int ret) |
00f660ea CF |
277 | { |
278 | test_finish = true; | |
279 | } | |
280 | ||
281 | int main(int argc, char *argv[]) | |
282 | { | |
283 | int opt; | |
284 | bool cfg_test_traffic = false; | |
285 | bool cfg_test_cookie = false; | |
286 | ||
287 | if (argc != 3) | |
288 | return usage(); | |
289 | while ((opt = getopt(argc, argv, "ts")) != -1) { | |
290 | switch (opt) { | |
291 | case 't': | |
292 | cfg_test_traffic = true; | |
293 | break; | |
294 | case 's': | |
295 | cfg_test_cookie = true; | |
296 | break; | |
51570a5a | 297 | |
00f660ea CF |
298 | default: |
299 | printf("unknown option %c\n", opt); | |
300 | usage(); | |
301 | return -1; | |
302 | } | |
303 | } | |
304 | maps_create(); | |
305 | prog_load(); | |
306 | prog_attach_iptables(argv[2]); | |
307 | if (cfg_test_traffic) { | |
308 | if (signal(SIGINT, finish) == SIG_ERR) | |
ad990dbe AG |
309 | error(1, errno, "register SIGINT handler failed"); |
310 | if (signal(SIGTERM, finish) == SIG_ERR) | |
311 | error(1, errno, "register SIGTERM handler failed"); | |
00f660ea CF |
312 | while (!test_finish) { |
313 | print_table(); | |
314 | printf("\n"); | |
315 | sleep(1); | |
316 | }; | |
317 | } else if (cfg_test_cookie) { | |
318 | udp_client(); | |
319 | } | |
320 | close(prog_fd); | |
321 | close(map_fd); | |
51570a5a CF |
322 | return 0; |
323 | } |