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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_endian.h"
17#include "bpf_rlimit.h"
18#include "bpf_util.h"
19
20#define CG_PATH "/foo"
21#define MAX_INSNS 512
22
23char bpf_log_buf[BPF_LOG_BUF_SIZE];
24static bool verbose = false;
25
26struct sock_test {
27 const char *descr;
28 /* BPF prog properties */
29 struct bpf_insn insns[MAX_INSNS];
30 enum bpf_attach_type expected_attach_type;
31 enum bpf_attach_type attach_type;
32 /* Socket properties */
33 int domain;
34 int type;
35 /* Endpoint to bind() to */
36 const char *ip;
37 unsigned short port;
38 /* Expected test result */
39 enum {
40 LOAD_REJECT,
41 ATTACH_REJECT,
42 BIND_REJECT,
43 SUCCESS,
44 } result;
45};
46
47static struct sock_test tests[] = {
48 {
49 "bind4 load with invalid access: src_ip6",
50 .insns = {
51 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
52 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
53 offsetof(struct bpf_sock, src_ip6[0])),
54 BPF_MOV64_IMM(BPF_REG_0, 1),
55 BPF_EXIT_INSN(),
56 },
57 BPF_CGROUP_INET4_POST_BIND,
58 BPF_CGROUP_INET4_POST_BIND,
59 0,
60 0,
61 NULL,
62 0,
63 LOAD_REJECT,
64 },
65 {
66 "bind4 load with invalid access: mark",
67 .insns = {
68 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
69 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
70 offsetof(struct bpf_sock, mark)),
71 BPF_MOV64_IMM(BPF_REG_0, 1),
72 BPF_EXIT_INSN(),
73 },
74 BPF_CGROUP_INET4_POST_BIND,
75 BPF_CGROUP_INET4_POST_BIND,
76 0,
77 0,
78 NULL,
79 0,
80 LOAD_REJECT,
81 },
82 {
83 "bind6 load with invalid access: src_ip4",
84 .insns = {
85 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
86 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
87 offsetof(struct bpf_sock, src_ip4)),
88 BPF_MOV64_IMM(BPF_REG_0, 1),
89 BPF_EXIT_INSN(),
90 },
91 BPF_CGROUP_INET6_POST_BIND,
92 BPF_CGROUP_INET6_POST_BIND,
93 0,
94 0,
95 NULL,
96 0,
97 LOAD_REJECT,
98 },
99 {
100 "sock_create load with invalid access: src_port",
101 .insns = {
102 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
103 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
104 offsetof(struct bpf_sock, src_port)),
105 BPF_MOV64_IMM(BPF_REG_0, 1),
106 BPF_EXIT_INSN(),
107 },
108 BPF_CGROUP_INET_SOCK_CREATE,
109 BPF_CGROUP_INET_SOCK_CREATE,
110 0,
111 0,
112 NULL,
113 0,
114 LOAD_REJECT,
115 },
116 {
117 "sock_create load w/o expected_attach_type (compat mode)",
118 .insns = {
119 BPF_MOV64_IMM(BPF_REG_0, 1),
120 BPF_EXIT_INSN(),
121 },
122 0,
123 BPF_CGROUP_INET_SOCK_CREATE,
124 AF_INET,
125 SOCK_STREAM,
126 "127.0.0.1",
127 8097,
128 SUCCESS,
129 },
130 {
131 "sock_create load w/ expected_attach_type",
132 .insns = {
133 BPF_MOV64_IMM(BPF_REG_0, 1),
134 BPF_EXIT_INSN(),
135 },
136 BPF_CGROUP_INET_SOCK_CREATE,
137 BPF_CGROUP_INET_SOCK_CREATE,
138 AF_INET,
139 SOCK_STREAM,
140 "127.0.0.1",
141 8097,
142 SUCCESS,
143 },
144 {
145 "attach type mismatch bind4 vs bind6",
146 .insns = {
147 BPF_MOV64_IMM(BPF_REG_0, 1),
148 BPF_EXIT_INSN(),
149 },
150 BPF_CGROUP_INET4_POST_BIND,
151 BPF_CGROUP_INET6_POST_BIND,
152 0,
153 0,
154 NULL,
155 0,
156 ATTACH_REJECT,
157 },
158 {
159 "attach type mismatch bind6 vs bind4",
160 .insns = {
161 BPF_MOV64_IMM(BPF_REG_0, 1),
162 BPF_EXIT_INSN(),
163 },
164 BPF_CGROUP_INET6_POST_BIND,
165 BPF_CGROUP_INET4_POST_BIND,
166 0,
167 0,
168 NULL,
169 0,
170 ATTACH_REJECT,
171 },
172 {
173 "attach type mismatch default vs bind4",
174 .insns = {
175 BPF_MOV64_IMM(BPF_REG_0, 1),
176 BPF_EXIT_INSN(),
177 },
178 0,
179 BPF_CGROUP_INET4_POST_BIND,
180 0,
181 0,
182 NULL,
183 0,
184 ATTACH_REJECT,
185 },
186 {
187 "attach type mismatch bind6 vs sock_create",
188 .insns = {
189 BPF_MOV64_IMM(BPF_REG_0, 1),
190 BPF_EXIT_INSN(),
191 },
192 BPF_CGROUP_INET6_POST_BIND,
193 BPF_CGROUP_INET_SOCK_CREATE,
194 0,
195 0,
196 NULL,
197 0,
198 ATTACH_REJECT,
199 },
200 {
201 "bind4 reject all",
202 .insns = {
203 BPF_MOV64_IMM(BPF_REG_0, 0),
204 BPF_EXIT_INSN(),
205 },
206 BPF_CGROUP_INET4_POST_BIND,
207 BPF_CGROUP_INET4_POST_BIND,
208 AF_INET,
209 SOCK_STREAM,
210 "0.0.0.0",
211 0,
212 BIND_REJECT,
213 },
214 {
215 "bind6 reject all",
216 .insns = {
217 BPF_MOV64_IMM(BPF_REG_0, 0),
218 BPF_EXIT_INSN(),
219 },
220 BPF_CGROUP_INET6_POST_BIND,
221 BPF_CGROUP_INET6_POST_BIND,
222 AF_INET6,
223 SOCK_STREAM,
224 "::",
225 0,
226 BIND_REJECT,
227 },
228 {
229 "bind6 deny specific IP & port",
230 .insns = {
231 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
232
233 /* if (ip == expected && port == expected) */
234 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
235 offsetof(struct bpf_sock, src_ip6[3])),
236 BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
237 __bpf_constant_ntohl(0x00000001), 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,
267 __bpf_constant_ntohl(0x7F000001), 4),
268 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
269 offsetof(struct bpf_sock, src_port)),
270 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2),
271
272 /* return ALLOW; */
273 BPF_MOV64_IMM(BPF_REG_0, 1),
274 BPF_JMP_A(1),
275
276 /* else return DENY; */
277 BPF_MOV64_IMM(BPF_REG_0, 0),
278 BPF_EXIT_INSN(),
279 },
280 BPF_CGROUP_INET4_POST_BIND,
281 BPF_CGROUP_INET4_POST_BIND,
282 AF_INET,
283 SOCK_STREAM,
284 "127.0.0.1",
285 4098,
286 SUCCESS,
287 },
288 {
289 "bind4 allow all",
290 .insns = {
291 BPF_MOV64_IMM(BPF_REG_0, 1),
292 BPF_EXIT_INSN(),
293 },
294 BPF_CGROUP_INET4_POST_BIND,
295 BPF_CGROUP_INET4_POST_BIND,
296 AF_INET,
297 SOCK_STREAM,
298 "0.0.0.0",
299 0,
300 SUCCESS,
301 },
302 {
303 "bind6 allow all",
304 .insns = {
305 BPF_MOV64_IMM(BPF_REG_0, 1),
306 BPF_EXIT_INSN(),
307 },
308 BPF_CGROUP_INET6_POST_BIND,
309 BPF_CGROUP_INET6_POST_BIND,
310 AF_INET6,
311 SOCK_STREAM,
312 "::",
313 0,
314 SUCCESS,
315 },
316};
317
318static size_t probe_prog_length(const struct bpf_insn *fp)
319{
320 size_t len;
321
322 for (len = MAX_INSNS - 1; len > 0; --len)
323 if (fp[len].code != 0 || fp[len].imm != 0)
324 break;
325 return len + 1;
326}
327
328static int load_sock_prog(const struct bpf_insn *prog,
329 enum bpf_attach_type attach_type)
330{
331 struct bpf_load_program_attr attr;
332 int ret;
333
334 memset(&attr, 0, sizeof(struct bpf_load_program_attr));
335 attr.prog_type = BPF_PROG_TYPE_CGROUP_SOCK;
336 attr.expected_attach_type = attach_type;
337 attr.insns = prog;
338 attr.insns_cnt = probe_prog_length(attr.insns);
339 attr.license = "GPL";
340 attr.log_level = 2;
341
342 ret = bpf_load_program_xattr(&attr, bpf_log_buf, BPF_LOG_BUF_SIZE);
343 if (verbose && ret < 0)
344 fprintf(stderr, "%s\n", bpf_log_buf);
345
346 return ret;
347}
348
349static int attach_sock_prog(int cgfd, int progfd,
350 enum bpf_attach_type attach_type)
351{
352 return bpf_prog_attach(progfd, cgfd, attach_type, BPF_F_ALLOW_OVERRIDE);
353}
354
355static int bind_sock(int domain, int type, const char *ip, unsigned short port)
356{
357 struct sockaddr_storage addr;
358 struct sockaddr_in6 *addr6;
359 struct sockaddr_in *addr4;
360 int sockfd = -1;
361 socklen_t len;
362 int err = 0;
363
364 sockfd = socket(domain, type, 0);
365 if (sockfd < 0)
366 goto err;
367
368 memset(&addr, 0, sizeof(addr));
369
370 if (domain == AF_INET) {
371 len = sizeof(struct sockaddr_in);
372 addr4 = (struct sockaddr_in *)&addr;
373 addr4->sin_family = domain;
374 addr4->sin_port = htons(port);
375 if (inet_pton(domain, ip, (void *)&addr4->sin_addr) != 1)
376 goto err;
377 } else if (domain == AF_INET6) {
378 len = sizeof(struct sockaddr_in6);
379 addr6 = (struct sockaddr_in6 *)&addr;
380 addr6->sin6_family = domain;
381 addr6->sin6_port = htons(port);
382 if (inet_pton(domain, ip, (void *)&addr6->sin6_addr) != 1)
383 goto err;
384 } else {
385 goto err;
386 }
387
388 if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1)
389 goto err;
390
391 goto out;
392err:
393 err = -1;
394out:
395 close(sockfd);
396 return err;
397}
398
399static int run_test_case(int cgfd, const struct sock_test *test)
400{
401 int progfd = -1;
402 int err = 0;
403
404 printf("Test case: %s .. ", test->descr);
405 progfd = load_sock_prog(test->insns, test->expected_attach_type);
406 if (progfd < 0) {
407 if (test->result == LOAD_REJECT)
408 goto out;
409 else
410 goto err;
411 }
412
413 if (attach_sock_prog(cgfd, progfd, test->attach_type) == -1) {
414 if (test->result == ATTACH_REJECT)
415 goto out;
416 else
417 goto err;
418 }
419
420 if (bind_sock(test->domain, test->type, test->ip, test->port) == -1) {
421 /* sys_bind() may fail for different reasons, errno has to be
422 * checked to confirm that BPF program rejected it.
423 */
424 if (test->result == BIND_REJECT && errno == EPERM)
425 goto out;
426 else
427 goto err;
428 }
429
430
431 if (test->result != SUCCESS)
432 goto err;
433
434 goto out;
435err:
436 err = -1;
437out:
438 /* Detaching w/o checking return code: best effort attempt. */
439 if (progfd != -1)
440 bpf_prog_detach(cgfd, test->attach_type);
441 close(progfd);
442 printf("[%s]\n", err ? "FAIL" : "PASS");
443 return err;
444}
445
446static int run_tests(int cgfd)
447{
448 int passes = 0;
449 int fails = 0;
450 int i;
451
452 for (i = 0; i < ARRAY_SIZE(tests); ++i) {
453 if (run_test_case(cgfd, &tests[i]))
454 ++fails;
455 else
456 ++passes;
457 }
458 printf("Summary: %d PASSED, %d FAILED\n", passes, fails);
459 return fails ? -1 : 0;
460}
461
462int main(int argc, char **argv)
463{
464 int cgfd = -1;
465 int err = 0;
466
467 if (setup_cgroup_environment())
468 goto err;
469
470 cgfd = create_and_get_cgroup(CG_PATH);
471 if (cgfd < 0)
472 goto err;
473
474 if (join_cgroup(CG_PATH))
475 goto err;
476
477 if (run_tests(cgfd))
478 goto err;
479
480 goto out;
481err:
482 err = -1;
483out:
484 close(cgfd);
485 cleanup_cgroup_environment();
486 return err;
487}