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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), | |
91c960b0 BJ |
150 | BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_9, BPF_REG_1, |
151 | offsetof(struct stats, packets)), | |
51570a5a CF |
152 | BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6, |
153 | offsetof(struct __sk_buff, len)), | |
91c960b0 BJ |
154 | BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_9, BPF_REG_1, |
155 | offsetof(struct stats, bytes)), | |
51570a5a CF |
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; | |
50b796e6 | 170 | char rules[256]; |
51570a5a CF |
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 | } | |
50b796e6 KKD |
178 | ret = snprintf(rules, sizeof(rules), |
179 | "iptables -A OUTPUT -m bpf --object-pinned %s -j ACCEPT", | |
180 | file); | |
181 | if (ret < 0 || ret >= sizeof(rules)) { | |
182 | printf("error constructing iptables command\n"); | |
183 | exit(1); | |
184 | } | |
51570a5a CF |
185 | ret = system(rules); |
186 | if (ret < 0) { | |
187 | printf("iptables rule update failed: %d/n", WEXITSTATUS(ret)); | |
188 | exit(1); | |
189 | } | |
190 | } | |
191 | ||
192 | static void print_table(void) | |
193 | { | |
194 | struct stats curEntry; | |
195 | uint32_t curN = UINT32_MAX; | |
00f660ea CF |
196 | uint32_t nextN; |
197 | int res; | |
51570a5a CF |
198 | |
199 | while (bpf_map_get_next_key(map_fd, &curN, &nextN) > -1) { | |
200 | curN = nextN; | |
201 | res = bpf_map_lookup_elem(map_fd, &curN, &curEntry); | |
202 | if (res < 0) { | |
203 | error(1, errno, "fail to get entry value of Key: %u\n", | |
204 | curN); | |
205 | } else { | |
206 | printf("cookie: %u, uid: 0x%x, Packet Count: %lu," | |
207 | " Bytes Count: %lu\n", curN, curEntry.uid, | |
208 | curEntry.packets, curEntry.bytes); | |
209 | } | |
210 | } | |
211 | } | |
212 | ||
00f660ea | 213 | static void udp_client(void) |
51570a5a | 214 | { |
00f660ea CF |
215 | struct sockaddr_in si_other = {0}; |
216 | struct sockaddr_in si_me = {0}; | |
217 | struct stats dataEntry; | |
218 | int s_rcv, s_send, i, recv_len; | |
219 | char message = 'a'; | |
220 | char buf; | |
221 | uint64_t cookie; | |
222 | int res; | |
223 | socklen_t cookie_len = sizeof(cookie); | |
224 | socklen_t slen = sizeof(si_other); | |
225 | ||
226 | s_rcv = socket(PF_INET, SOCK_DGRAM, 0); | |
227 | if (s_rcv < 0) | |
228 | error(1, errno, "rcv socket creat failed!\n"); | |
229 | si_other.sin_family = AF_INET; | |
230 | si_other.sin_port = htons(PORT); | |
231 | if (inet_aton("127.0.0.1", &si_other.sin_addr) == 0) | |
232 | error(1, errno, "inet_aton\n"); | |
233 | if (bind(s_rcv, (struct sockaddr *)&si_other, sizeof(si_other)) == -1) | |
234 | error(1, errno, "bind\n"); | |
235 | s_send = socket(PF_INET, SOCK_DGRAM, 0); | |
236 | if (s_send < 0) | |
237 | error(1, errno, "send socket creat failed!\n"); | |
238 | res = getsockopt(s_send, SOL_SOCKET, SO_COOKIE, &cookie, &cookie_len); | |
239 | if (res < 0) | |
240 | printf("get cookie failed: %s\n", strerror(errno)); | |
241 | res = bpf_map_lookup_elem(map_fd, &cookie, &dataEntry); | |
242 | if (res != -1) | |
243 | error(1, errno, "socket stat found while flow not active\n"); | |
244 | for (i = 0; i < 10; i++) { | |
245 | res = sendto(s_send, &message, sizeof(message), 0, | |
246 | (struct sockaddr *)&si_other, slen); | |
247 | if (res == -1) | |
248 | error(1, errno, "send\n"); | |
249 | if (res != sizeof(message)) | |
250 | error(1, 0, "%uB != %luB\n", res, sizeof(message)); | |
251 | recv_len = recvfrom(s_rcv, &buf, sizeof(buf), 0, | |
252 | (struct sockaddr *)&si_me, &slen); | |
253 | if (recv_len < 0) | |
20cfb7a0 | 254 | error(1, errno, "receive\n"); |
00f660ea CF |
255 | res = memcmp(&(si_other.sin_addr), &(si_me.sin_addr), |
256 | sizeof(si_me.sin_addr)); | |
257 | if (res != 0) | |
258 | error(1, EFAULT, "sender addr error: %d\n", res); | |
259 | printf("Message received: %c\n", buf); | |
260 | res = bpf_map_lookup_elem(map_fd, &cookie, &dataEntry); | |
261 | if (res < 0) | |
262 | error(1, errno, "lookup sk stat failed, cookie: %lu\n", | |
263 | cookie); | |
264 | printf("cookie: %lu, uid: 0x%x, Packet Count: %lu," | |
265 | " Bytes Count: %lu\n\n", cookie, dataEntry.uid, | |
266 | dataEntry.packets, dataEntry.bytes); | |
51570a5a | 267 | } |
00f660ea CF |
268 | close(s_send); |
269 | close(s_rcv); | |
270 | } | |
51570a5a | 271 | |
00f660ea CF |
272 | static int usage(void) |
273 | { | |
274 | printf("Usage: ./run_cookie_uid_helper_example.sh" | |
275 | " bpfObjName -option\n" | |
276 | " -t traffic monitor test\n" | |
277 | " -s getsockopt cookie test\n"); | |
278 | return 1; | |
279 | } | |
51570a5a | 280 | |
4784726f | 281 | static void finish(int ret) |
00f660ea CF |
282 | { |
283 | test_finish = true; | |
284 | } | |
285 | ||
286 | int main(int argc, char *argv[]) | |
287 | { | |
288 | int opt; | |
289 | bool cfg_test_traffic = false; | |
290 | bool cfg_test_cookie = false; | |
291 | ||
292 | if (argc != 3) | |
293 | return usage(); | |
294 | while ((opt = getopt(argc, argv, "ts")) != -1) { | |
295 | switch (opt) { | |
296 | case 't': | |
297 | cfg_test_traffic = true; | |
298 | break; | |
299 | case 's': | |
300 | cfg_test_cookie = true; | |
301 | break; | |
51570a5a | 302 | |
00f660ea CF |
303 | default: |
304 | printf("unknown option %c\n", opt); | |
305 | usage(); | |
306 | return -1; | |
307 | } | |
308 | } | |
309 | maps_create(); | |
310 | prog_load(); | |
311 | prog_attach_iptables(argv[2]); | |
312 | if (cfg_test_traffic) { | |
313 | if (signal(SIGINT, finish) == SIG_ERR) | |
ad990dbe AG |
314 | error(1, errno, "register SIGINT handler failed"); |
315 | if (signal(SIGTERM, finish) == SIG_ERR) | |
316 | error(1, errno, "register SIGTERM handler failed"); | |
00f660ea CF |
317 | while (!test_finish) { |
318 | print_table(); | |
319 | printf("\n"); | |
320 | sleep(1); | |
1132b998 | 321 | } |
00f660ea CF |
322 | } else if (cfg_test_cookie) { |
323 | udp_client(); | |
324 | } | |
325 | close(prog_fd); | |
326 | close(map_fd); | |
51570a5a CF |
327 | return 0; |
328 | } |