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1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2018 Facebook
3
4#include <stdio.h>
5#include <stdlib.h>
6#include <unistd.h>
7
8#include <arpa/inet.h>
9#include <sys/types.h>
10#include <sys/socket.h>
11
12#include <linux/filter.h>
13
14#include <bpf/bpf.h>
15#include <bpf/libbpf.h>
16
17#include "cgroup_helpers.h"
18#include "bpf_rlimit.h"
19
20#define CG_PATH "/foo"
21#define CONNECT4_PROG_PATH "./connect4_prog.o"
22#define CONNECT6_PROG_PATH "./connect6_prog.o"
23
24#define SERV4_IP "192.168.1.254"
25#define SERV4_REWRITE_IP "127.0.0.1"
26#define SERV4_PORT 4040
27#define SERV4_REWRITE_PORT 4444
28
29#define SERV6_IP "face:b00c:1234:5678::abcd"
30#define SERV6_REWRITE_IP "::1"
31#define SERV6_PORT 6060
32#define SERV6_REWRITE_PORT 6666
33
34#define INET_NTOP_BUF 40
35
36typedef int (*load_fn)(enum bpf_attach_type, const char *comment);
37typedef int (*info_fn)(int, struct sockaddr *, socklen_t *);
38
39struct program {
40 enum bpf_attach_type type;
41 load_fn loadfn;
42 int fd;
43 const char *name;
44 enum bpf_attach_type invalid_type;
45};
46
47char bpf_log_buf[BPF_LOG_BUF_SIZE];
48
49static int mk_sockaddr(int domain, const char *ip, unsigned short port,
50 struct sockaddr *addr, socklen_t addr_len)
51{
52 struct sockaddr_in6 *addr6;
53 struct sockaddr_in *addr4;
54
55 if (domain != AF_INET && domain != AF_INET6) {
56 log_err("Unsupported address family");
57 return -1;
58 }
59
60 memset(addr, 0, addr_len);
61
62 if (domain == AF_INET) {
63 if (addr_len < sizeof(struct sockaddr_in))
64 return -1;
65 addr4 = (struct sockaddr_in *)addr;
66 addr4->sin_family = domain;
67 addr4->sin_port = htons(port);
68 if (inet_pton(domain, ip, (void *)&addr4->sin_addr) != 1) {
69 log_err("Invalid IPv4: %s", ip);
70 return -1;
71 }
72 } else if (domain == AF_INET6) {
73 if (addr_len < sizeof(struct sockaddr_in6))
74 return -1;
75 addr6 = (struct sockaddr_in6 *)addr;
76 addr6->sin6_family = domain;
77 addr6->sin6_port = htons(port);
78 if (inet_pton(domain, ip, (void *)&addr6->sin6_addr) != 1) {
79 log_err("Invalid IPv6: %s", ip);
80 return -1;
81 }
82 }
83
84 return 0;
85}
86
87static int load_insns(enum bpf_attach_type attach_type,
88 const struct bpf_insn *insns, size_t insns_cnt,
89 const char *comment)
90{
91 struct bpf_load_program_attr load_attr;
92 int ret;
93
94 memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
95 load_attr.prog_type = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
96 load_attr.expected_attach_type = attach_type;
97 load_attr.insns = insns;
98 load_attr.insns_cnt = insns_cnt;
99 load_attr.license = "GPL";
100
101 ret = bpf_load_program_xattr(&load_attr, bpf_log_buf, BPF_LOG_BUF_SIZE);
102 if (ret < 0 && comment) {
103 log_err(">>> Loading %s program error.\n"
104 ">>> Output from verifier:\n%s\n-------\n",
105 comment, bpf_log_buf);
106 }
107
108 return ret;
109}
110
111/* [1] These testing programs try to read different context fields, including
112 * narrow loads of different sizes from user_ip4 and user_ip6, and write to
113 * those allowed to be overridden.
114 *
115 * [2] BPF_LD_IMM64 & BPF_JMP_REG are used below whenever there is a need to
116 * compare a register with unsigned 32bit integer. BPF_JMP_IMM can't be used
117 * in such cases since it accepts only _signed_ 32bit integer as IMM
118 * argument. Also note that BPF_LD_IMM64 contains 2 instructions what matters
119 * to count jumps properly.
120 */
121
122static int bind4_prog_load(enum bpf_attach_type attach_type,
123 const char *comment)
124{
125 union {
126 uint8_t u4_addr8[4];
127 uint16_t u4_addr16[2];
128 uint32_t u4_addr32;
129 } ip4;
130 struct sockaddr_in addr4_rw;
131
132 if (inet_pton(AF_INET, SERV4_IP, (void *)&ip4) != 1) {
133 log_err("Invalid IPv4: %s", SERV4_IP);
134 return -1;
135 }
136
137 if (mk_sockaddr(AF_INET, SERV4_REWRITE_IP, SERV4_REWRITE_PORT,
138 (struct sockaddr *)&addr4_rw, sizeof(addr4_rw)) == -1)
139 return -1;
140
141 /* See [1]. */
142 struct bpf_insn insns[] = {
143 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
144
145 /* if (sk.family == AF_INET && */
146 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
147 offsetof(struct bpf_sock_addr, family)),
148 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET, 16),
149
150 /* (sk.type == SOCK_DGRAM || sk.type == SOCK_STREAM) && */
151 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
152 offsetof(struct bpf_sock_addr, type)),
153 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, SOCK_DGRAM, 1),
154 BPF_JMP_A(1),
155 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, SOCK_STREAM, 12),
156
157 /* 1st_byte_of_user_ip4 == expected && */
158 BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
159 offsetof(struct bpf_sock_addr, user_ip4)),
160 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr8[0], 10),
161
162 /* 1st_half_of_user_ip4 == expected && */
163 BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_6,
164 offsetof(struct bpf_sock_addr, user_ip4)),
165 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr16[0], 8),
166
167 /* whole_user_ip4 == expected) { */
168 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
169 offsetof(struct bpf_sock_addr, user_ip4)),
170 BPF_LD_IMM64(BPF_REG_8, ip4.u4_addr32), /* See [2]. */
171 BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_8, 4),
172
173 /* user_ip4 = addr4_rw.sin_addr */
174 BPF_MOV32_IMM(BPF_REG_7, addr4_rw.sin_addr.s_addr),
175 BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
176 offsetof(struct bpf_sock_addr, user_ip4)),
177
178 /* user_port = addr4_rw.sin_port */
179 BPF_MOV32_IMM(BPF_REG_7, addr4_rw.sin_port),
180 BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
181 offsetof(struct bpf_sock_addr, user_port)),
182 /* } */
183
184 /* return 1 */
185 BPF_MOV64_IMM(BPF_REG_0, 1),
186 BPF_EXIT_INSN(),
187 };
188
189 return load_insns(attach_type, insns,
190 sizeof(insns) / sizeof(struct bpf_insn), comment);
191}
192
193static int bind6_prog_load(enum bpf_attach_type attach_type,
194 const char *comment)
195{
196 struct sockaddr_in6 addr6_rw;
197 struct in6_addr ip6;
198
199 if (inet_pton(AF_INET6, SERV6_IP, (void *)&ip6) != 1) {
200 log_err("Invalid IPv6: %s", SERV6_IP);
201 return -1;
202 }
203
204 if (mk_sockaddr(AF_INET6, SERV6_REWRITE_IP, SERV6_REWRITE_PORT,
205 (struct sockaddr *)&addr6_rw, sizeof(addr6_rw)) == -1)
206 return -1;
207
208 /* See [1]. */
209 struct bpf_insn insns[] = {
210 BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
211
212 /* if (sk.family == AF_INET6 && */
213 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
214 offsetof(struct bpf_sock_addr, family)),
215 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET6, 18),
216
217 /* 5th_byte_of_user_ip6 == expected && */
218 BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
219 offsetof(struct bpf_sock_addr, user_ip6[1])),
220 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip6.s6_addr[4], 16),
221
222 /* 3rd_half_of_user_ip6 == expected && */
223 BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_6,
224 offsetof(struct bpf_sock_addr, user_ip6[1])),
225 BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip6.s6_addr16[2], 14),
226
227 /* last_word_of_user_ip6 == expected) { */
228 BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
229 offsetof(struct bpf_sock_addr, user_ip6[3])),
230 BPF_LD_IMM64(BPF_REG_8, ip6.s6_addr32[3]), /* See [2]. */
231 BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_8, 10),
232
233
234#define STORE_IPV6_WORD(N) \
235 BPF_MOV32_IMM(BPF_REG_7, addr6_rw.sin6_addr.s6_addr32[N]), \
236 BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7, \
237 offsetof(struct bpf_sock_addr, user_ip6[N]))
238
239 /* user_ip6 = addr6_rw.sin6_addr */
240 STORE_IPV6_WORD(0),
241 STORE_IPV6_WORD(1),
242 STORE_IPV6_WORD(2),
243 STORE_IPV6_WORD(3),
244
245 /* user_port = addr6_rw.sin6_port */
246 BPF_MOV32_IMM(BPF_REG_7, addr6_rw.sin6_port),
247 BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
248 offsetof(struct bpf_sock_addr, user_port)),
249
250 /* } */
251
252 /* return 1 */
253 BPF_MOV64_IMM(BPF_REG_0, 1),
254 BPF_EXIT_INSN(),
255 };
256
257 return load_insns(attach_type, insns,
258 sizeof(insns) / sizeof(struct bpf_insn), comment);
259}
260
261static int connect_prog_load_path(const char *path,
262 enum bpf_attach_type attach_type,
263 const char *comment)
264{
265 struct bpf_prog_load_attr attr;
266 struct bpf_object *obj;
267 int prog_fd;
268
269 memset(&attr, 0, sizeof(struct bpf_prog_load_attr));
270 attr.file = path;
271 attr.prog_type = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
272 attr.expected_attach_type = attach_type;
273
274 if (bpf_prog_load_xattr(&attr, &obj, &prog_fd)) {
275 if (comment)
276 log_err(">>> Loading %s program at %s error.\n",
277 comment, path);
278 return -1;
279 }
280
281 return prog_fd;
282}
283
284static int connect4_prog_load(enum bpf_attach_type attach_type,
285 const char *comment)
286{
287 return connect_prog_load_path(CONNECT4_PROG_PATH, attach_type, comment);
288}
289
290static int connect6_prog_load(enum bpf_attach_type attach_type,
291 const char *comment)
292{
293 return connect_prog_load_path(CONNECT6_PROG_PATH, attach_type, comment);
294}
295
296static void print_ip_port(int sockfd, info_fn fn, const char *fmt)
297{
298 char addr_buf[INET_NTOP_BUF];
299 struct sockaddr_storage addr;
300 struct sockaddr_in6 *addr6;
301 struct sockaddr_in *addr4;
302 socklen_t addr_len;
303 unsigned short port;
304 void *nip;
305
306 addr_len = sizeof(struct sockaddr_storage);
307 memset(&addr, 0, addr_len);
308
309 if (fn(sockfd, (struct sockaddr *)&addr, (socklen_t *)&addr_len) == 0) {
310 if (addr.ss_family == AF_INET) {
311 addr4 = (struct sockaddr_in *)&addr;
312 nip = (void *)&addr4->sin_addr;
313 port = ntohs(addr4->sin_port);
314 } else if (addr.ss_family == AF_INET6) {
315 addr6 = (struct sockaddr_in6 *)&addr;
316 nip = (void *)&addr6->sin6_addr;
317 port = ntohs(addr6->sin6_port);
318 } else {
319 return;
320 }
321 const char *addr_str =
322 inet_ntop(addr.ss_family, nip, addr_buf, INET_NTOP_BUF);
323 printf(fmt, addr_str ? addr_str : "??", port);
324 }
325}
326
327static void print_local_ip_port(int sockfd, const char *fmt)
328{
329 print_ip_port(sockfd, getsockname, fmt);
330}
331
332static void print_remote_ip_port(int sockfd, const char *fmt)
333{
334 print_ip_port(sockfd, getpeername, fmt);
335}
336
337static int start_server(int type, const struct sockaddr_storage *addr,
338 socklen_t addr_len)
339{
340
341 int fd;
342
343 fd = socket(addr->ss_family, type, 0);
344 if (fd == -1) {
345 log_err("Failed to create server socket");
346 goto out;
347 }
348
349 if (bind(fd, (const struct sockaddr *)addr, addr_len) == -1) {
350 log_err("Failed to bind server socket");
351 goto close_out;
352 }
353
354 if (type == SOCK_STREAM) {
355 if (listen(fd, 128) == -1) {
356 log_err("Failed to listen on server socket");
357 goto close_out;
358 }
359 }
360
361 print_local_ip_port(fd, "\t Actual: bind(%s, %d)\n");
362
363 goto out;
364close_out:
365 close(fd);
366 fd = -1;
367out:
368 return fd;
369}
370
371static int connect_to_server(int type, const struct sockaddr_storage *addr,
372 socklen_t addr_len)
373{
374 int domain;
375 int fd;
376
377 domain = addr->ss_family;
378
379 if (domain != AF_INET && domain != AF_INET6) {
380 log_err("Unsupported address family");
381 return -1;
382 }
383
384 fd = socket(domain, type, 0);
385 if (fd == -1) {
386 log_err("Failed to creating client socket");
387 return -1;
388 }
389
390 if (connect(fd, (const struct sockaddr *)addr, addr_len) == -1) {
391 log_err("Fail to connect to server");
392 goto err;
393 }
394
395 print_remote_ip_port(fd, "\t Actual: connect(%s, %d)");
396 print_local_ip_port(fd, " from (%s, %d)\n");
397
398 return 0;
399err:
400 close(fd);
401 return -1;
402}
403
404static void print_test_case_num(int domain, int type)
405{
406 static int test_num;
407
408 printf("Test case #%d (%s/%s):\n", ++test_num,
409 (domain == AF_INET ? "IPv4" :
410 domain == AF_INET6 ? "IPv6" :
411 "unknown_domain"),
412 (type == SOCK_STREAM ? "TCP" :
413 type == SOCK_DGRAM ? "UDP" :
414 "unknown_type"));
415}
416
417static int run_test_case(int domain, int type, const char *ip,
418 unsigned short port)
419{
420 struct sockaddr_storage addr;
421 socklen_t addr_len = sizeof(addr);
422 int servfd = -1;
423 int err = 0;
424
425 print_test_case_num(domain, type);
426
427 if (mk_sockaddr(domain, ip, port, (struct sockaddr *)&addr,
428 addr_len) == -1)
429 return -1;
430
431 printf("\tRequested: bind(%s, %d) ..\n", ip, port);
432 servfd = start_server(type, &addr, addr_len);
433 if (servfd == -1)
434 goto err;
435
436 printf("\tRequested: connect(%s, %d) from (*, *) ..\n", ip, port);
437 if (connect_to_server(type, &addr, addr_len))
438 goto err;
439
440 goto out;
441err:
442 err = -1;
443out:
444 close(servfd);
445 return err;
446}
447
448static void close_progs_fds(struct program *progs, size_t prog_cnt)
449{
450 size_t i;
451
452 for (i = 0; i < prog_cnt; ++i) {
453 close(progs[i].fd);
454 progs[i].fd = -1;
455 }
456}
457
458static int load_and_attach_progs(int cgfd, struct program *progs,
459 size_t prog_cnt)
460{
461 size_t i;
462
463 for (i = 0; i < prog_cnt; ++i) {
464 printf("Load %s with invalid type (can pollute stderr) ",
465 progs[i].name);
466 fflush(stdout);
467 progs[i].fd = progs[i].loadfn(progs[i].invalid_type, NULL);
468 if (progs[i].fd != -1) {
469 log_err("Load with invalid type accepted for %s",
470 progs[i].name);
471 goto err;
472 }
473 printf("... REJECTED\n");
474
475 printf("Load %s with valid type", progs[i].name);
476 progs[i].fd = progs[i].loadfn(progs[i].type, progs[i].name);
477 if (progs[i].fd == -1) {
478 log_err("Failed to load program %s", progs[i].name);
479 goto err;
480 }
481 printf(" ... OK\n");
482
483 printf("Attach %s with invalid type", progs[i].name);
484 if (bpf_prog_attach(progs[i].fd, cgfd, progs[i].invalid_type,
485 BPF_F_ALLOW_OVERRIDE) != -1) {
486 log_err("Attach with invalid type accepted for %s",
487 progs[i].name);
488 goto err;
489 }
490 printf(" ... REJECTED\n");
491
492 printf("Attach %s with valid type", progs[i].name);
493 if (bpf_prog_attach(progs[i].fd, cgfd, progs[i].type,
494 BPF_F_ALLOW_OVERRIDE) == -1) {
495 log_err("Failed to attach program %s", progs[i].name);
496 goto err;
497 }
498 printf(" ... OK\n");
499 }
500
501 return 0;
502err:
503 close_progs_fds(progs, prog_cnt);
504 return -1;
505}
506
507static int run_domain_test(int domain, int cgfd, struct program *progs,
508 size_t prog_cnt, const char *ip, unsigned short port)
509{
510 int err = 0;
511
512 if (load_and_attach_progs(cgfd, progs, prog_cnt) == -1)
513 goto err;
514
515 if (run_test_case(domain, SOCK_STREAM, ip, port) == -1)
516 goto err;
517
518 if (run_test_case(domain, SOCK_DGRAM, ip, port) == -1)
519 goto err;
520
521 goto out;
522err:
523 err = -1;
524out:
525 close_progs_fds(progs, prog_cnt);
526 return err;
527}
528
529static int run_test(void)
530{
531 size_t inet6_prog_cnt;
532 size_t inet_prog_cnt;
533 int cgfd = -1;
534 int err = 0;
535
536 struct program inet6_progs[] = {
537 {BPF_CGROUP_INET6_BIND, bind6_prog_load, -1, "bind6",
538 BPF_CGROUP_INET4_BIND},
539 {BPF_CGROUP_INET6_CONNECT, connect6_prog_load, -1, "connect6",
540 BPF_CGROUP_INET4_CONNECT},
541 };
542 inet6_prog_cnt = sizeof(inet6_progs) / sizeof(struct program);
543
544 struct program inet_progs[] = {
545 {BPF_CGROUP_INET4_BIND, bind4_prog_load, -1, "bind4",
546 BPF_CGROUP_INET6_BIND},
547 {BPF_CGROUP_INET4_CONNECT, connect4_prog_load, -1, "connect4",
548 BPF_CGROUP_INET6_CONNECT},
549 };
550 inet_prog_cnt = sizeof(inet_progs) / sizeof(struct program);
551
552 if (setup_cgroup_environment())
553 goto err;
554
555 cgfd = create_and_get_cgroup(CG_PATH);
556 if (!cgfd)
557 goto err;
558
559 if (join_cgroup(CG_PATH))
560 goto err;
561
562 if (run_domain_test(AF_INET, cgfd, inet_progs, inet_prog_cnt, SERV4_IP,
563 SERV4_PORT) == -1)
564 goto err;
565
566 if (run_domain_test(AF_INET6, cgfd, inet6_progs, inet6_prog_cnt,
567 SERV6_IP, SERV6_PORT) == -1)
568 goto err;
569
570 goto out;
571err:
572 err = -1;
573out:
574 close(cgfd);
575 cleanup_cgroup_environment();
576 printf(err ? "### FAIL\n" : "### SUCCESS\n");
577 return err;
578}
579
580int main(int argc, char **argv)
581{
582 if (argc < 2) {
583 fprintf(stderr,
584 "%s has to be run via %s.sh. Skip direct run.\n",
585 argv[0], argv[0]);
586 exit(0);
587 }
588 return run_test();
589}