1 | // SPDX-License-Identifier: GPL-2.0 |
2 | // Copyright (c) 2018 Facebook |
3 | |
4 | #include <stdio.h> |
5 | #include <unistd.h> |
6 | |
7 | #include <arpa/inet.h> |
8 | #include <sys/types.h> |
9 | #include <sys/socket.h> |
10 | |
11 | #include <linux/filter.h> |
12 | |
13 | #include <bpf/bpf.h> |
14 | |
15 | #include "cgroup_helpers.h" |
16 | #include <bpf/bpf_endian.h> |
17 | #include "bpf_util.h" |
18 | |
19 | #define CG_PATH "/foo" |
20 | #define MAX_INSNS 512 |
21 | |
22 | char bpf_log_buf[BPF_LOG_BUF_SIZE]; |
23 | static bool verbose = false; |
24 | |
25 | struct sock_test { |
26 | const char *descr; |
27 | /* BPF prog properties */ |
28 | struct bpf_insn insns[MAX_INSNS]; |
29 | enum bpf_attach_type expected_attach_type; |
30 | enum bpf_attach_type attach_type; |
31 | /* Socket properties */ |
32 | int domain; |
33 | int type; |
34 | /* Endpoint to bind() to */ |
35 | const char *ip; |
36 | unsigned short port; |
37 | unsigned short port_retry; |
38 | /* Expected test result */ |
39 | enum { |
40 | LOAD_REJECT, |
41 | ATTACH_REJECT, |
42 | BIND_REJECT, |
43 | SUCCESS, |
44 | RETRY_SUCCESS, |
45 | RETRY_REJECT |
46 | } result; |
47 | }; |
48 | |
49 | static struct sock_test tests[] = { |
50 | { |
51 | .descr = "bind4 load with invalid access: src_ip6" , |
52 | .insns = { |
53 | BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
54 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
55 | offsetof(struct bpf_sock, src_ip6[0])), |
56 | BPF_MOV64_IMM(BPF_REG_0, 1), |
57 | BPF_EXIT_INSN(), |
58 | }, |
59 | .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
60 | .attach_type = BPF_CGROUP_INET4_POST_BIND, |
61 | .result = LOAD_REJECT, |
62 | }, |
63 | { |
64 | .descr = "bind4 load with invalid access: mark" , |
65 | .insns = { |
66 | BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
67 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
68 | offsetof(struct bpf_sock, mark)), |
69 | BPF_MOV64_IMM(BPF_REG_0, 1), |
70 | BPF_EXIT_INSN(), |
71 | }, |
72 | .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
73 | .attach_type = BPF_CGROUP_INET4_POST_BIND, |
74 | .result = LOAD_REJECT, |
75 | }, |
76 | { |
77 | .descr = "bind6 load with invalid access: src_ip4" , |
78 | .insns = { |
79 | BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
80 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
81 | offsetof(struct bpf_sock, src_ip4)), |
82 | BPF_MOV64_IMM(BPF_REG_0, 1), |
83 | BPF_EXIT_INSN(), |
84 | }, |
85 | .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
86 | .attach_type = BPF_CGROUP_INET6_POST_BIND, |
87 | .result = LOAD_REJECT, |
88 | }, |
89 | { |
90 | .descr = "sock_create load with invalid access: src_port" , |
91 | .insns = { |
92 | BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
93 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
94 | offsetof(struct bpf_sock, src_port)), |
95 | BPF_MOV64_IMM(BPF_REG_0, 1), |
96 | BPF_EXIT_INSN(), |
97 | }, |
98 | .expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE, |
99 | .attach_type = BPF_CGROUP_INET_SOCK_CREATE, |
100 | .result = LOAD_REJECT, |
101 | }, |
102 | { |
103 | .descr = "sock_create load w/o expected_attach_type (compat mode)" , |
104 | .insns = { |
105 | BPF_MOV64_IMM(BPF_REG_0, 1), |
106 | BPF_EXIT_INSN(), |
107 | }, |
108 | .expected_attach_type = 0, |
109 | .attach_type = BPF_CGROUP_INET_SOCK_CREATE, |
110 | .domain = AF_INET, |
111 | .type = SOCK_STREAM, |
112 | .ip = "127.0.0.1" , |
113 | .port = 8097, |
114 | .result = SUCCESS, |
115 | }, |
116 | { |
117 | .descr = "sock_create load w/ expected_attach_type" , |
118 | .insns = { |
119 | BPF_MOV64_IMM(BPF_REG_0, 1), |
120 | BPF_EXIT_INSN(), |
121 | }, |
122 | .expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE, |
123 | .attach_type = BPF_CGROUP_INET_SOCK_CREATE, |
124 | .domain = AF_INET, |
125 | .type = SOCK_STREAM, |
126 | .ip = "127.0.0.1" , |
127 | .port = 8097, |
128 | .result = SUCCESS, |
129 | }, |
130 | { |
131 | .descr = "attach type mismatch bind4 vs bind6" , |
132 | .insns = { |
133 | BPF_MOV64_IMM(BPF_REG_0, 1), |
134 | BPF_EXIT_INSN(), |
135 | }, |
136 | .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
137 | .attach_type = BPF_CGROUP_INET6_POST_BIND, |
138 | .result = ATTACH_REJECT, |
139 | }, |
140 | { |
141 | .descr = "attach type mismatch bind6 vs bind4" , |
142 | .insns = { |
143 | BPF_MOV64_IMM(BPF_REG_0, 1), |
144 | BPF_EXIT_INSN(), |
145 | }, |
146 | .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
147 | .attach_type = BPF_CGROUP_INET4_POST_BIND, |
148 | .result = ATTACH_REJECT, |
149 | }, |
150 | { |
151 | .descr = "attach type mismatch default vs bind4" , |
152 | .insns = { |
153 | BPF_MOV64_IMM(BPF_REG_0, 1), |
154 | BPF_EXIT_INSN(), |
155 | }, |
156 | .expected_attach_type = 0, |
157 | .attach_type = BPF_CGROUP_INET4_POST_BIND, |
158 | .result = ATTACH_REJECT, |
159 | }, |
160 | { |
161 | .descr = "attach type mismatch bind6 vs sock_create" , |
162 | .insns = { |
163 | BPF_MOV64_IMM(BPF_REG_0, 1), |
164 | BPF_EXIT_INSN(), |
165 | }, |
166 | .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
167 | .attach_type = BPF_CGROUP_INET_SOCK_CREATE, |
168 | .result = ATTACH_REJECT, |
169 | }, |
170 | { |
171 | .descr = "bind4 reject all" , |
172 | .insns = { |
173 | BPF_MOV64_IMM(BPF_REG_0, 0), |
174 | BPF_EXIT_INSN(), |
175 | }, |
176 | .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
177 | .attach_type = BPF_CGROUP_INET4_POST_BIND, |
178 | .domain = AF_INET, |
179 | .type = SOCK_STREAM, |
180 | .ip = "0.0.0.0" , |
181 | .result = BIND_REJECT, |
182 | }, |
183 | { |
184 | .descr = "bind6 reject all" , |
185 | .insns = { |
186 | BPF_MOV64_IMM(BPF_REG_0, 0), |
187 | BPF_EXIT_INSN(), |
188 | }, |
189 | .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
190 | .attach_type = BPF_CGROUP_INET6_POST_BIND, |
191 | .domain = AF_INET6, |
192 | .type = SOCK_STREAM, |
193 | .ip = "::" , |
194 | .result = BIND_REJECT, |
195 | }, |
196 | { |
197 | .descr = "bind6 deny specific IP & port" , |
198 | .insns = { |
199 | BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
200 | |
201 | /* if (ip == expected && port == expected) */ |
202 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
203 | offsetof(struct bpf_sock, src_ip6[3])), |
204 | BPF_JMP_IMM(BPF_JNE, BPF_REG_7, |
205 | __bpf_constant_ntohl(0x00000001), 4), |
206 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
207 | offsetof(struct bpf_sock, src_port)), |
208 | BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2), |
209 | |
210 | /* return DENY; */ |
211 | BPF_MOV64_IMM(BPF_REG_0, 0), |
212 | BPF_JMP_A(1), |
213 | |
214 | /* else return ALLOW; */ |
215 | BPF_MOV64_IMM(BPF_REG_0, 1), |
216 | BPF_EXIT_INSN(), |
217 | }, |
218 | .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
219 | .attach_type = BPF_CGROUP_INET6_POST_BIND, |
220 | .domain = AF_INET6, |
221 | .type = SOCK_STREAM, |
222 | .ip = "::1" , |
223 | .port = 8193, |
224 | .result = BIND_REJECT, |
225 | }, |
226 | { |
227 | .descr = "bind4 allow specific IP & port" , |
228 | .insns = { |
229 | BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
230 | |
231 | /* if (ip == expected && port == expected) */ |
232 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
233 | offsetof(struct bpf_sock, src_ip4)), |
234 | BPF_JMP_IMM(BPF_JNE, BPF_REG_7, |
235 | __bpf_constant_ntohl(0x7F000001), 4), |
236 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
237 | offsetof(struct bpf_sock, src_port)), |
238 | BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2), |
239 | |
240 | /* return ALLOW; */ |
241 | BPF_MOV64_IMM(BPF_REG_0, 1), |
242 | BPF_JMP_A(1), |
243 | |
244 | /* else return DENY; */ |
245 | BPF_MOV64_IMM(BPF_REG_0, 0), |
246 | BPF_EXIT_INSN(), |
247 | }, |
248 | .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
249 | .attach_type = BPF_CGROUP_INET4_POST_BIND, |
250 | .domain = AF_INET, |
251 | .type = SOCK_STREAM, |
252 | .ip = "127.0.0.1" , |
253 | .port = 4098, |
254 | .result = SUCCESS, |
255 | }, |
256 | { |
257 | .descr = "bind4 deny specific IP & port of TCP, and retry" , |
258 | .insns = { |
259 | BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
260 | |
261 | /* if (ip == expected && port == expected) */ |
262 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
263 | offsetof(struct bpf_sock, src_ip4)), |
264 | BPF_JMP_IMM(BPF_JNE, BPF_REG_7, |
265 | __bpf_constant_ntohl(0x7F000001), 4), |
266 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
267 | offsetof(struct bpf_sock, src_port)), |
268 | BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2), |
269 | |
270 | /* return DENY; */ |
271 | BPF_MOV64_IMM(BPF_REG_0, 0), |
272 | BPF_JMP_A(1), |
273 | |
274 | /* else return ALLOW; */ |
275 | BPF_MOV64_IMM(BPF_REG_0, 1), |
276 | BPF_EXIT_INSN(), |
277 | }, |
278 | .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
279 | .attach_type = BPF_CGROUP_INET4_POST_BIND, |
280 | .domain = AF_INET, |
281 | .type = SOCK_STREAM, |
282 | .ip = "127.0.0.1" , |
283 | .port = 4098, |
284 | .port_retry = 5000, |
285 | .result = RETRY_SUCCESS, |
286 | }, |
287 | { |
288 | .descr = "bind4 deny specific IP & port of UDP, and retry" , |
289 | .insns = { |
290 | BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
291 | |
292 | /* if (ip == expected && port == expected) */ |
293 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
294 | offsetof(struct bpf_sock, src_ip4)), |
295 | BPF_JMP_IMM(BPF_JNE, BPF_REG_7, |
296 | __bpf_constant_ntohl(0x7F000001), 4), |
297 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
298 | offsetof(struct bpf_sock, src_port)), |
299 | BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2), |
300 | |
301 | /* return DENY; */ |
302 | BPF_MOV64_IMM(BPF_REG_0, 0), |
303 | BPF_JMP_A(1), |
304 | |
305 | /* else return ALLOW; */ |
306 | BPF_MOV64_IMM(BPF_REG_0, 1), |
307 | BPF_EXIT_INSN(), |
308 | }, |
309 | .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
310 | .attach_type = BPF_CGROUP_INET4_POST_BIND, |
311 | .domain = AF_INET, |
312 | .type = SOCK_DGRAM, |
313 | .ip = "127.0.0.1" , |
314 | .port = 4098, |
315 | .port_retry = 5000, |
316 | .result = RETRY_SUCCESS, |
317 | }, |
318 | { |
319 | .descr = "bind6 deny specific IP & port, and retry" , |
320 | .insns = { |
321 | BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
322 | |
323 | /* if (ip == expected && port == expected) */ |
324 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
325 | offsetof(struct bpf_sock, src_ip6[3])), |
326 | BPF_JMP_IMM(BPF_JNE, BPF_REG_7, |
327 | __bpf_constant_ntohl(0x00000001), 4), |
328 | BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
329 | offsetof(struct bpf_sock, src_port)), |
330 | BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2), |
331 | |
332 | /* return DENY; */ |
333 | BPF_MOV64_IMM(BPF_REG_0, 0), |
334 | BPF_JMP_A(1), |
335 | |
336 | /* else return ALLOW; */ |
337 | BPF_MOV64_IMM(BPF_REG_0, 1), |
338 | BPF_EXIT_INSN(), |
339 | }, |
340 | .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
341 | .attach_type = BPF_CGROUP_INET6_POST_BIND, |
342 | .domain = AF_INET6, |
343 | .type = SOCK_STREAM, |
344 | .ip = "::1" , |
345 | .port = 8193, |
346 | .port_retry = 9000, |
347 | .result = RETRY_SUCCESS, |
348 | }, |
349 | { |
350 | .descr = "bind4 allow all" , |
351 | .insns = { |
352 | BPF_MOV64_IMM(BPF_REG_0, 1), |
353 | BPF_EXIT_INSN(), |
354 | }, |
355 | .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
356 | .attach_type = BPF_CGROUP_INET4_POST_BIND, |
357 | .domain = AF_INET, |
358 | .type = SOCK_STREAM, |
359 | .ip = "0.0.0.0" , |
360 | .result = SUCCESS, |
361 | }, |
362 | { |
363 | .descr = "bind6 allow all" , |
364 | .insns = { |
365 | BPF_MOV64_IMM(BPF_REG_0, 1), |
366 | BPF_EXIT_INSN(), |
367 | }, |
368 | .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
369 | .attach_type = BPF_CGROUP_INET6_POST_BIND, |
370 | .domain = AF_INET6, |
371 | .type = SOCK_STREAM, |
372 | .ip = "::" , |
373 | .result = SUCCESS, |
374 | }, |
375 | }; |
376 | |
377 | static size_t probe_prog_length(const struct bpf_insn *fp) |
378 | { |
379 | size_t len; |
380 | |
381 | for (len = MAX_INSNS - 1; len > 0; --len) |
382 | if (fp[len].code != 0 || fp[len].imm != 0) |
383 | break; |
384 | return len + 1; |
385 | } |
386 | |
387 | static int load_sock_prog(const struct bpf_insn *prog, |
388 | enum bpf_attach_type attach_type) |
389 | { |
390 | LIBBPF_OPTS(bpf_prog_load_opts, opts); |
391 | int ret, insn_cnt; |
392 | |
393 | insn_cnt = probe_prog_length(fp: prog); |
394 | |
395 | opts.expected_attach_type = attach_type; |
396 | opts.log_buf = bpf_log_buf; |
397 | opts.log_size = BPF_LOG_BUF_SIZE; |
398 | opts.log_level = 2; |
399 | |
400 | ret = bpf_prog_load(BPF_PROG_TYPE_CGROUP_SOCK, NULL, "GPL" , prog, insn_cnt, &opts); |
401 | if (verbose && ret < 0) |
402 | fprintf(stderr, "%s\n" , bpf_log_buf); |
403 | |
404 | return ret; |
405 | } |
406 | |
407 | static int attach_sock_prog(int cgfd, int progfd, |
408 | enum bpf_attach_type attach_type) |
409 | { |
410 | return bpf_prog_attach(progfd, cgfd, attach_type, BPF_F_ALLOW_OVERRIDE); |
411 | } |
412 | |
413 | static int bind_sock(int domain, int type, const char *ip, |
414 | unsigned short port, unsigned short port_retry) |
415 | { |
416 | struct sockaddr_storage addr; |
417 | struct sockaddr_in6 *addr6; |
418 | struct sockaddr_in *addr4; |
419 | int sockfd = -1; |
420 | socklen_t len; |
421 | int res = SUCCESS; |
422 | |
423 | sockfd = socket(domain, type, 0); |
424 | if (sockfd < 0) |
425 | goto err; |
426 | |
427 | memset(&addr, 0, sizeof(addr)); |
428 | |
429 | if (domain == AF_INET) { |
430 | len = sizeof(struct sockaddr_in); |
431 | addr4 = (struct sockaddr_in *)&addr; |
432 | addr4->sin_family = domain; |
433 | addr4->sin_port = htons(port); |
434 | if (inet_pton(domain, ip, (void *)&addr4->sin_addr) != 1) |
435 | goto err; |
436 | } else if (domain == AF_INET6) { |
437 | len = sizeof(struct sockaddr_in6); |
438 | addr6 = (struct sockaddr_in6 *)&addr; |
439 | addr6->sin6_family = domain; |
440 | addr6->sin6_port = htons(port); |
441 | if (inet_pton(domain, ip, (void *)&addr6->sin6_addr) != 1) |
442 | goto err; |
443 | } else { |
444 | goto err; |
445 | } |
446 | |
447 | if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1) { |
448 | /* sys_bind() may fail for different reasons, errno has to be |
449 | * checked to confirm that BPF program rejected it. |
450 | */ |
451 | if (errno != EPERM) |
452 | goto err; |
453 | if (port_retry) |
454 | goto retry; |
455 | res = BIND_REJECT; |
456 | goto out; |
457 | } |
458 | |
459 | goto out; |
460 | retry: |
461 | if (domain == AF_INET) |
462 | addr4->sin_port = htons(port_retry); |
463 | else |
464 | addr6->sin6_port = htons(port_retry); |
465 | if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1) { |
466 | if (errno != EPERM) |
467 | goto err; |
468 | res = RETRY_REJECT; |
469 | } else { |
470 | res = RETRY_SUCCESS; |
471 | } |
472 | goto out; |
473 | err: |
474 | res = -1; |
475 | out: |
476 | close(sockfd); |
477 | return res; |
478 | } |
479 | |
480 | static int run_test_case(int cgfd, const struct sock_test *test) |
481 | { |
482 | int progfd = -1; |
483 | int err = 0; |
484 | int res; |
485 | |
486 | printf("Test case: %s .. " , test->descr); |
487 | progfd = load_sock_prog(prog: test->insns, attach_type: test->expected_attach_type); |
488 | if (progfd < 0) { |
489 | if (test->result == LOAD_REJECT) |
490 | goto out; |
491 | else |
492 | goto err; |
493 | } |
494 | |
495 | if (attach_sock_prog(cgfd, progfd, attach_type: test->attach_type) < 0) { |
496 | if (test->result == ATTACH_REJECT) |
497 | goto out; |
498 | else |
499 | goto err; |
500 | } |
501 | |
502 | res = bind_sock(domain: test->domain, type: test->type, ip: test->ip, port: test->port, |
503 | port_retry: test->port_retry); |
504 | if (res > 0 && test->result == res) |
505 | goto out; |
506 | |
507 | err: |
508 | err = -1; |
509 | out: |
510 | /* Detaching w/o checking return code: best effort attempt. */ |
511 | if (progfd != -1) |
512 | bpf_prog_detach(cgfd, test->attach_type); |
513 | close(progfd); |
514 | printf("[%s]\n" , err ? "FAIL" : "PASS" ); |
515 | return err; |
516 | } |
517 | |
518 | static int run_tests(int cgfd) |
519 | { |
520 | int passes = 0; |
521 | int fails = 0; |
522 | int i; |
523 | |
524 | for (i = 0; i < ARRAY_SIZE(tests); ++i) { |
525 | if (run_test_case(cgfd, &tests[i])) |
526 | ++fails; |
527 | else |
528 | ++passes; |
529 | } |
530 | printf("Summary: %d PASSED, %d FAILED\n" , passes, fails); |
531 | return fails ? -1 : 0; |
532 | } |
533 | |
534 | int main(int argc, char **argv) |
535 | { |
536 | int cgfd = -1; |
537 | int err = 0; |
538 | |
539 | cgfd = cgroup_setup_and_join(CG_PATH); |
540 | if (cgfd < 0) |
541 | goto err; |
542 | |
543 | /* Use libbpf 1.0 API mode */ |
544 | libbpf_set_strict_mode(LIBBPF_STRICT_ALL); |
545 | |
546 | if (run_tests(cgfd)) |
547 | goto err; |
548 | |
549 | goto out; |
550 | err: |
551 | err = -1; |
552 | out: |
553 | close(cgfd); |
554 | cleanup_cgroup_environment(); |
555 | return err; |
556 | } |
557 | |