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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_rlimit.h"
17
18#ifndef ARRAY_SIZE
19# define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
20#endif
21
22#define CG_PATH "/foo"
23#define MAX_INSNS 512
24
25char bpf_log_buf[BPF_LOG_BUF_SIZE];
26
27struct sock_test {
28 const char *descr;
29 /* BPF prog properties */
30 struct bpf_insn insns[MAX_INSNS];
31 enum bpf_attach_type expected_attach_type;
32 enum bpf_attach_type attach_type;
33 /* Socket properties */
34 int domain;
35 int type;
36 /* Endpoint to bind() to */
37 const char *ip;
38 unsigned short port;
39 /* Expected test result */
40 enum {
41 LOAD_REJECT,
42 ATTACH_REJECT,
43 BIND_REJECT,
44 SUCCESS,
45 } result;
46};
47
48static struct sock_test tests[] = {
49 {
50 "bind4 load with invalid access: src_ip6",
51 .insns = {
52 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
53 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
54 offsetof(struct bpf_sock, src_ip6[0])),
55 BPF_MOV64_IMM(BPF_REG_0, 1),
56 BPF_EXIT_INSN(),
57 },
58 BPF_CGROUP_INET4_POST_BIND,
59 BPF_CGROUP_INET4_POST_BIND,
60 0,
61 0,
62 NULL,
63 0,
64 LOAD_REJECT,
65 },
66 {
67 "bind4 load with invalid access: mark",
68 .insns = {
69 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
70 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
71 offsetof(struct bpf_sock, mark)),
72 BPF_MOV64_IMM(BPF_REG_0, 1),
73 BPF_EXIT_INSN(),
74 },
75 BPF_CGROUP_INET4_POST_BIND,
76 BPF_CGROUP_INET4_POST_BIND,
77 0,
78 0,
79 NULL,
80 0,
81 LOAD_REJECT,
82 },
83 {
84 "bind6 load with invalid access: src_ip4",
85 .insns = {
86 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
87 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
88 offsetof(struct bpf_sock, src_ip4)),
89 BPF_MOV64_IMM(BPF_REG_0, 1),
90 BPF_EXIT_INSN(),
91 },
92 BPF_CGROUP_INET6_POST_BIND,
93 BPF_CGROUP_INET6_POST_BIND,
94 0,
95 0,
96 NULL,
97 0,
98 LOAD_REJECT,
99 },
100 {
101 "sock_create load with invalid access: src_port",
102 .insns = {
103 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
104 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
105 offsetof(struct bpf_sock, src_port)),
106 BPF_MOV64_IMM(BPF_REG_0, 1),
107 BPF_EXIT_INSN(),
108 },
109 BPF_CGROUP_INET_SOCK_CREATE,
110 BPF_CGROUP_INET_SOCK_CREATE,
111 0,
112 0,
113 NULL,
114 0,
115 LOAD_REJECT,
116 },
117 {
118 "sock_create load w/o expected_attach_type (compat mode)",
119 .insns = {
120 BPF_MOV64_IMM(BPF_REG_0, 1),
121 BPF_EXIT_INSN(),
122 },
123 0,
124 BPF_CGROUP_INET_SOCK_CREATE,
125 AF_INET,
126 SOCK_STREAM,
127 "127.0.0.1",
128 8097,
129 SUCCESS,
130 },
131 {
132 "sock_create load w/ expected_attach_type",
133 .insns = {
134 BPF_MOV64_IMM(BPF_REG_0, 1),
135 BPF_EXIT_INSN(),
136 },
137 BPF_CGROUP_INET_SOCK_CREATE,
138 BPF_CGROUP_INET_SOCK_CREATE,
139 AF_INET,
140 SOCK_STREAM,
141 "127.0.0.1",
142 8097,
143 SUCCESS,
144 },
145 {
146 "attach type mismatch bind4 vs bind6",
147 .insns = {
148 BPF_MOV64_IMM(BPF_REG_0, 1),
149 BPF_EXIT_INSN(),
150 },
151 BPF_CGROUP_INET4_POST_BIND,
152 BPF_CGROUP_INET6_POST_BIND,
153 0,
154 0,
155 NULL,
156 0,
157 ATTACH_REJECT,
158 },
159 {
160 "attach type mismatch bind6 vs bind4",
161 .insns = {
162 BPF_MOV64_IMM(BPF_REG_0, 1),
163 BPF_EXIT_INSN(),
164 },
165 BPF_CGROUP_INET6_POST_BIND,
166 BPF_CGROUP_INET4_POST_BIND,
167 0,
168 0,
169 NULL,
170 0,
171 ATTACH_REJECT,
172 },
173 {
174 "attach type mismatch default vs bind4",
175 .insns = {
176 BPF_MOV64_IMM(BPF_REG_0, 1),
177 BPF_EXIT_INSN(),
178 },
179 0,
180 BPF_CGROUP_INET4_POST_BIND,
181 0,
182 0,
183 NULL,
184 0,
185 ATTACH_REJECT,
186 },
187 {
188 "attach type mismatch bind6 vs sock_create",
189 .insns = {
190 BPF_MOV64_IMM(BPF_REG_0, 1),
191 BPF_EXIT_INSN(),
192 },
193 BPF_CGROUP_INET6_POST_BIND,
194 BPF_CGROUP_INET_SOCK_CREATE,
195 0,
196 0,
197 NULL,
198 0,
199 ATTACH_REJECT,
200 },
201 {
202 "bind4 reject all",
203 .insns = {
204 BPF_MOV64_IMM(BPF_REG_0, 0),
205 BPF_EXIT_INSN(),
206 },
207 BPF_CGROUP_INET4_POST_BIND,
208 BPF_CGROUP_INET4_POST_BIND,
209 AF_INET,
210 SOCK_STREAM,
211 "0.0.0.0",
212 0,
213 BIND_REJECT,
214 },
215 {
216 "bind6 reject all",
217 .insns = {
218 BPF_MOV64_IMM(BPF_REG_0, 0),
219 BPF_EXIT_INSN(),
220 },
221 BPF_CGROUP_INET6_POST_BIND,
222 BPF_CGROUP_INET6_POST_BIND,
223 AF_INET6,
224 SOCK_STREAM,
225 "::",
226 0,
227 BIND_REJECT,
228 },
229 {
230 "bind6 deny specific IP & port",
231 .insns = {
232 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
233
234 /* if (ip == expected && port == expected) */
235 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
236 offsetof(struct bpf_sock, src_ip6[3])),
237 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x01000000, 4),
238 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
239 offsetof(struct bpf_sock, src_port)),
240 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2),
241
242 /* return DENY; */
243 BPF_MOV64_IMM(BPF_REG_0, 0),
244 BPF_JMP_A(1),
245
246 /* else return ALLOW; */
247 BPF_MOV64_IMM(BPF_REG_0, 1),
248 BPF_EXIT_INSN(),
249 },
250 BPF_CGROUP_INET6_POST_BIND,
251 BPF_CGROUP_INET6_POST_BIND,
252 AF_INET6,
253 SOCK_STREAM,
254 "::1",
255 8193,
256 BIND_REJECT,
257 },
258 {
259 "bind4 allow specific IP & port",
260 .insns = {
261 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
262
263 /* if (ip == expected && port == expected) */
264 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
265 offsetof(struct bpf_sock, src_ip4)),
266 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x0100007F, 4),
267 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
268 offsetof(struct bpf_sock, src_port)),
269 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2),
270
271 /* return ALLOW; */
272 BPF_MOV64_IMM(BPF_REG_0, 1),
273 BPF_JMP_A(1),
274
275 /* else return DENY; */
276 BPF_MOV64_IMM(BPF_REG_0, 0),
277 BPF_EXIT_INSN(),
278 },
279 BPF_CGROUP_INET4_POST_BIND,
280 BPF_CGROUP_INET4_POST_BIND,
281 AF_INET,
282 SOCK_STREAM,
283 "127.0.0.1",
284 4098,
285 SUCCESS,
286 },
287 {
288 "bind4 allow all",
289 .insns = {
290 BPF_MOV64_IMM(BPF_REG_0, 1),
291 BPF_EXIT_INSN(),
292 },
293 BPF_CGROUP_INET4_POST_BIND,
294 BPF_CGROUP_INET4_POST_BIND,
295 AF_INET,
296 SOCK_STREAM,
297 "0.0.0.0",
298 0,
299 SUCCESS,
300 },
301 {
302 "bind6 allow all",
303 .insns = {
304 BPF_MOV64_IMM(BPF_REG_0, 1),
305 BPF_EXIT_INSN(),
306 },
307 BPF_CGROUP_INET6_POST_BIND,
308 BPF_CGROUP_INET6_POST_BIND,
309 AF_INET6,
310 SOCK_STREAM,
311 "::",
312 0,
313 SUCCESS,
314 },
315};
316
317static size_t probe_prog_length(const struct bpf_insn *fp)
318{
319 size_t len;
320
321 for (len = MAX_INSNS - 1; len > 0; --len)
322 if (fp[len].code != 0 || fp[len].imm != 0)
323 break;
324 return len + 1;
325}
326
327static int load_sock_prog(const struct bpf_insn *prog,
328 enum bpf_attach_type attach_type)
329{
330 struct bpf_load_program_attr attr;
331
332 memset(&attr, 0, sizeof(struct bpf_load_program_attr));
333 attr.prog_type = BPF_PROG_TYPE_CGROUP_SOCK;
334 attr.expected_attach_type = attach_type;
335 attr.insns = prog;
336 attr.insns_cnt = probe_prog_length(attr.insns);
337 attr.license = "GPL";
338
339 return bpf_load_program_xattr(&attr, bpf_log_buf, BPF_LOG_BUF_SIZE);
340}
341
342static int attach_sock_prog(int cgfd, int progfd,
343 enum bpf_attach_type attach_type)
344{
345 return bpf_prog_attach(progfd, cgfd, attach_type, BPF_F_ALLOW_OVERRIDE);
346}
347
348static int bind_sock(int domain, int type, const char *ip, unsigned short port)
349{
350 struct sockaddr_storage addr;
351 struct sockaddr_in6 *addr6;
352 struct sockaddr_in *addr4;
353 int sockfd = -1;
354 socklen_t len;
355 int err = 0;
356
357 sockfd = socket(domain, type, 0);
358 if (sockfd < 0)
359 goto err;
360
361 memset(&addr, 0, sizeof(addr));
362
363 if (domain == AF_INET) {
364 len = sizeof(struct sockaddr_in);
365 addr4 = (struct sockaddr_in *)&addr;
366 addr4->sin_family = domain;
367 addr4->sin_port = htons(port);
368 if (inet_pton(domain, ip, (void *)&addr4->sin_addr) != 1)
369 goto err;
370 } else if (domain == AF_INET6) {
371 len = sizeof(struct sockaddr_in6);
372 addr6 = (struct sockaddr_in6 *)&addr;
373 addr6->sin6_family = domain;
374 addr6->sin6_port = htons(port);
375 if (inet_pton(domain, ip, (void *)&addr6->sin6_addr) != 1)
376 goto err;
377 } else {
378 goto err;
379 }
380
381 if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1)
382 goto err;
383
384 goto out;
385err:
386 err = -1;
387out:
388 close(sockfd);
389 return err;
390}
391
392static int run_test_case(int cgfd, const struct sock_test *test)
393{
394 int progfd = -1;
395 int err = 0;
396
397 printf("Test case: %s .. ", test->descr);
398 progfd = load_sock_prog(test->insns, test->expected_attach_type);
399 if (progfd < 0) {
400 if (test->result == LOAD_REJECT)
401 goto out;
402 else
403 goto err;
404 }
405
406 if (attach_sock_prog(cgfd, progfd, test->attach_type) == -1) {
407 if (test->result == ATTACH_REJECT)
408 goto out;
409 else
410 goto err;
411 }
412
413 if (bind_sock(test->domain, test->type, test->ip, test->port) == -1) {
414 /* sys_bind() may fail for different reasons, errno has to be
415 * checked to confirm that BPF program rejected it.
416 */
417 if (test->result == BIND_REJECT && errno == EPERM)
418 goto out;
419 else
420 goto err;
421 }
422
423
424 if (test->result != SUCCESS)
425 goto err;
426
427 goto out;
428err:
429 err = -1;
430out:
431 /* Detaching w/o checking return code: best effort attempt. */
432 if (progfd != -1)
433 bpf_prog_detach(cgfd, test->attach_type);
434 close(progfd);
435 printf("[%s]\n", err ? "FAIL" : "PASS");
436 return err;
437}
438
439static int run_tests(int cgfd)
440{
441 int passes = 0;
442 int fails = 0;
443 int i;
444
445 for (i = 0; i < ARRAY_SIZE(tests); ++i) {
446 if (run_test_case(cgfd, &tests[i]))
447 ++fails;
448 else
449 ++passes;
450 }
451 printf("Summary: %d PASSED, %d FAILED\n", passes, fails);
452 return fails ? -1 : 0;
453}
454
455int main(int argc, char **argv)
456{
457 int cgfd = -1;
458 int err = 0;
459
460 if (setup_cgroup_environment())
461 goto err;
462
463 cgfd = create_and_get_cgroup(CG_PATH);
464 if (!cgfd)
465 goto err;
466
467 if (join_cgroup(CG_PATH))
468 goto err;
469
470 if (run_tests(cgfd))
471 goto err;
472
473 goto out;
474err:
475 err = -1;
476out:
477 close(cgfd);
478 cleanup_cgroup_environment();
479 return err;
480}