1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 // Copyright (C) 2017 Facebook
3 // Author: Roman Gushchin <guro@fb.com>
4
5 #define _XOPEN_SOURCE 500
6 #include <errno.h>
7 #include <fcntl.h>
8 #include <ftw.h>
9 #include <mntent.h>
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include <sys/stat.h>
14 #include <sys/types.h>
15 #include <unistd.h>
16
17 #include <bpf/bpf.h>
18 #include <bpf/btf.h>
19
20 #include "main.h"
21
22 static const int cgroup_attach_types[] = {
23 BPF_CGROUP_INET_INGRESS,
24 BPF_CGROUP_INET_EGRESS,
25 BPF_CGROUP_INET_SOCK_CREATE,
26 BPF_CGROUP_INET_SOCK_RELEASE,
27 BPF_CGROUP_INET4_BIND,
28 BPF_CGROUP_INET6_BIND,
29 BPF_CGROUP_INET4_POST_BIND,
30 BPF_CGROUP_INET6_POST_BIND,
31 BPF_CGROUP_INET4_CONNECT,
32 BPF_CGROUP_INET6_CONNECT,
33 BPF_CGROUP_UNIX_CONNECT,
34 BPF_CGROUP_INET4_GETPEERNAME,
35 BPF_CGROUP_INET6_GETPEERNAME,
36 BPF_CGROUP_UNIX_GETPEERNAME,
37 BPF_CGROUP_INET4_GETSOCKNAME,
38 BPF_CGROUP_INET6_GETSOCKNAME,
39 BPF_CGROUP_UNIX_GETSOCKNAME,
40 BPF_CGROUP_UDP4_SENDMSG,
41 BPF_CGROUP_UDP6_SENDMSG,
42 BPF_CGROUP_UNIX_SENDMSG,
43 BPF_CGROUP_UDP4_RECVMSG,
44 BPF_CGROUP_UDP6_RECVMSG,
45 BPF_CGROUP_UNIX_RECVMSG,
46 BPF_CGROUP_SOCK_OPS,
47 BPF_CGROUP_DEVICE,
48 BPF_CGROUP_SYSCTL,
49 BPF_CGROUP_GETSOCKOPT,
50 BPF_CGROUP_SETSOCKOPT,
51 BPF_LSM_CGROUP
52 };
53
54 #define HELP_SPEC_ATTACH_FLAGS \
55 "ATTACH_FLAGS := { multi | override }"
56
57 #define HELP_SPEC_ATTACH_TYPES \
58 " ATTACH_TYPE := { cgroup_inet_ingress | cgroup_inet_egress |\n" \
59 " cgroup_inet_sock_create | cgroup_sock_ops |\n" \
60 " cgroup_device | cgroup_inet4_bind |\n" \
61 " cgroup_inet6_bind | cgroup_inet4_post_bind |\n" \
62 " cgroup_inet6_post_bind | cgroup_inet4_connect |\n" \
63 " cgroup_inet6_connect | cgroup_unix_connect |\n" \
64 " cgroup_inet4_getpeername | cgroup_inet6_getpeername |\n" \
65 " cgroup_unix_getpeername | cgroup_inet4_getsockname |\n" \
66 " cgroup_inet6_getsockname | cgroup_unix_getsockname |\n" \
67 " cgroup_udp4_sendmsg | cgroup_udp6_sendmsg |\n" \
68 " cgroup_unix_sendmsg | cgroup_udp4_recvmsg |\n" \
69 " cgroup_udp6_recvmsg | cgroup_unix_recvmsg |\n" \
70 " cgroup_sysctl | cgroup_getsockopt |\n" \
71 " cgroup_setsockopt | cgroup_inet_sock_release }"
72
73 static unsigned int query_flags;
74 static struct btf *btf_vmlinux;
75 static __u32 btf_vmlinux_id;
76
77 static enum bpf_attach_type parse_attach_type(const char *str)
78 {
79 const char *attach_type_str;
80 enum bpf_attach_type type;
81
82 for (type = 0; ; type++) {
83 attach_type_str = libbpf_bpf_attach_type_str(type);
84 if (!attach_type_str)
85 break;
86 if (!strcmp(str, attach_type_str))
87 return type;
88 }
89
90 /* Also check traditionally used attach type strings. For these we keep
91 * allowing prefixed usage.
92 */
93 for (type = 0; ; type++) {
94 attach_type_str = bpf_attach_type_input_str(type);
95 if (!attach_type_str)
96 break;
97 if (is_prefix(str, attach_type_str))
98 return type;
99 }
100
101 return __MAX_BPF_ATTACH_TYPE;
102 }
103
104 static void guess_vmlinux_btf_id(__u32 attach_btf_obj_id)
105 {
106 struct bpf_btf_info btf_info = {};
107 __u32 btf_len = sizeof(btf_info);
108 char name[16] = {};
109 int err;
110 int fd;
111
112 btf_info.name = ptr_to_u64(name);
113 btf_info.name_len = sizeof(name);
114
115 fd = bpf_btf_get_fd_by_id(attach_btf_obj_id);
116 if (fd < 0)
117 return;
118
119 err = bpf_btf_get_info_by_fd(fd, &btf_info, &btf_len);
120 if (err)
121 goto out;
122
123 if (btf_info.kernel_btf && strncmp(name, "vmlinux", sizeof(name)) == 0)
124 btf_vmlinux_id = btf_info.id;
125
126 out:
127 close(fd);
128 }
129
130 static int show_bpf_prog(int id, enum bpf_attach_type attach_type,
131 const char *attach_flags_str,
132 int level)
133 {
134 char prog_name[MAX_PROG_FULL_NAME];
135 const char *attach_btf_name = NULL;
136 struct bpf_prog_info info = {};
137 const char *attach_type_str;
138 __u32 info_len = sizeof(info);
139 int prog_fd;
140
141 prog_fd = bpf_prog_get_fd_by_id(id);
142 if (prog_fd < 0)
143 return -1;
144
145 if (bpf_prog_get_info_by_fd(prog_fd, &info, &info_len)) {
146 close(prog_fd);
147 return -1;
148 }
149
150 attach_type_str = libbpf_bpf_attach_type_str(attach_type);
151
152 if (btf_vmlinux) {
153 if (!btf_vmlinux_id)
154 guess_vmlinux_btf_id(info.attach_btf_obj_id);
155
156 if (btf_vmlinux_id == info.attach_btf_obj_id &&
157 info.attach_btf_id < btf__type_cnt(btf_vmlinux)) {
158 const struct btf_type *t =
159 btf__type_by_id(btf_vmlinux, info.attach_btf_id);
160 attach_btf_name =
161 btf__name_by_offset(btf_vmlinux, t->name_off);
162 }
163 }
164
165 get_prog_full_name(&info, prog_fd, prog_name, sizeof(prog_name));
166 if (json_output) {
167 jsonw_start_object(json_wtr);
168 jsonw_uint_field(json_wtr, "id", info.id);
169 if (attach_type_str)
170 jsonw_string_field(json_wtr, "attach_type", attach_type_str);
171 else
172 jsonw_uint_field(json_wtr, "attach_type", attach_type);
173 if (!(query_flags & BPF_F_QUERY_EFFECTIVE))
174 jsonw_string_field(json_wtr, "attach_flags", attach_flags_str);
175 jsonw_string_field(json_wtr, "name", prog_name);
176 if (attach_btf_name)
177 jsonw_string_field(json_wtr, "attach_btf_name", attach_btf_name);
178 jsonw_uint_field(json_wtr, "attach_btf_obj_id", info.attach_btf_obj_id);
179 jsonw_uint_field(json_wtr, "attach_btf_id", info.attach_btf_id);
180 jsonw_end_object(json_wtr);
181 } else {
182 printf("%s%-8u ", level ? " " : "", info.id);
183 if (attach_type_str)
184 printf("%-15s", attach_type_str);
185 else
186 printf("type %-10u", attach_type);
187 if (query_flags & BPF_F_QUERY_EFFECTIVE)
188 printf(" %-15s", prog_name);
189 else
190 printf(" %-15s %-15s", attach_flags_str, prog_name);
191 if (attach_btf_name)
192 printf(" %-15s", attach_btf_name);
193 else if (info.attach_btf_id)
194 printf(" attach_btf_obj_id=%d attach_btf_id=%d",
195 info.attach_btf_obj_id, info.attach_btf_id);
196 printf("\n");
197 }
198
199 close(prog_fd);
200 return 0;
201 }
202
203 static int count_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type)
204 {
205 __u32 prog_cnt = 0;
206 int ret;
207
208 ret = bpf_prog_query(cgroup_fd, type, query_flags, NULL,
209 NULL, &prog_cnt);
210 if (ret)
211 return -1;
212
213 return prog_cnt;
214 }
215
216 static int cgroup_has_attached_progs(int cgroup_fd)
217 {
218 unsigned int i = 0;
219 bool no_prog = true;
220
221 for (i = 0; i < ARRAY_SIZE(cgroup_attach_types); i++) {
222 int count = count_attached_bpf_progs(cgroup_fd, cgroup_attach_types[i]);
223
224 if (count < 0)
225 return -1;
226
227 if (count > 0) {
228 no_prog = false;
229 break;
230 }
231 }
232
233 return no_prog ? 0 : 1;
234 }
235
236 static int show_effective_bpf_progs(int cgroup_fd, enum bpf_attach_type type,
237 int level)
238 {
239 LIBBPF_OPTS(bpf_prog_query_opts, p);
240 __u32 prog_ids[1024] = {0};
241 __u32 iter;
242 int ret;
243
244 p.query_flags = query_flags;
245 p.prog_cnt = ARRAY_SIZE(prog_ids);
246 p.prog_ids = prog_ids;
247
248 ret = bpf_prog_query_opts(cgroup_fd, type, &p);
249 if (ret)
250 return ret;
251
252 if (p.prog_cnt == 0)
253 return 0;
254
255 for (iter = 0; iter < p.prog_cnt; iter++)
256 show_bpf_prog(prog_ids[iter], type, NULL, level);
257
258 return 0;
259 }
260
261 static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type,
262 int level)
263 {
264 LIBBPF_OPTS(bpf_prog_query_opts, p);
265 __u32 prog_attach_flags[1024] = {0};
266 const char *attach_flags_str;
267 __u32 prog_ids[1024] = {0};
268 char buf[32];
269 __u32 iter;
270 int ret;
271
272 p.query_flags = query_flags;
273 p.prog_cnt = ARRAY_SIZE(prog_ids);
274 p.prog_ids = prog_ids;
275 p.prog_attach_flags = prog_attach_flags;
276
277 ret = bpf_prog_query_opts(cgroup_fd, type, &p);
278 if (ret)
279 return ret;
280
281 if (p.prog_cnt == 0)
282 return 0;
283
284 for (iter = 0; iter < p.prog_cnt; iter++) {
285 __u32 attach_flags;
286
287 attach_flags = prog_attach_flags[iter] ?: p.attach_flags;
288
289 switch (attach_flags) {
290 case BPF_F_ALLOW_MULTI:
291 attach_flags_str = "multi";
292 break;
293 case BPF_F_ALLOW_OVERRIDE:
294 attach_flags_str = "override";
295 break;
296 case 0:
297 attach_flags_str = "";
298 break;
299 default:
300 snprintf(buf, sizeof(buf), "unknown(%x)", attach_flags);
301 attach_flags_str = buf;
302 }
303
304 show_bpf_prog(prog_ids[iter], type,
305 attach_flags_str, level);
306 }
307
308 return 0;
309 }
310
311 static int show_bpf_progs(int cgroup_fd, enum bpf_attach_type type,
312 int level)
313 {
314 return query_flags & BPF_F_QUERY_EFFECTIVE ?
315 show_effective_bpf_progs(cgroup_fd, type, level) :
316 show_attached_bpf_progs(cgroup_fd, type, level);
317 }
318
319 static int do_show(int argc, char **argv)
320 {
321 enum bpf_attach_type type;
322 int has_attached_progs;
323 const char *path;
324 int cgroup_fd;
325 int ret = -1;
326
327 query_flags = 0;
328
329 if (!REQ_ARGS(1))
330 return -1;
331 path = GET_ARG();
332
333 while (argc) {
334 if (is_prefix(*argv, "effective")) {
335 if (query_flags & BPF_F_QUERY_EFFECTIVE) {
336 p_err("duplicated argument: %s", *argv);
337 return -1;
338 }
339 query_flags |= BPF_F_QUERY_EFFECTIVE;
340 NEXT_ARG();
341 } else {
342 p_err("expected no more arguments, 'effective', got: '%s'?",
343 *argv);
344 return -1;
345 }
346 }
347
348 cgroup_fd = open(path, O_RDONLY);
349 if (cgroup_fd < 0) {
350 p_err("can't open cgroup %s", path);
351 goto exit;
352 }
353
354 has_attached_progs = cgroup_has_attached_progs(cgroup_fd);
355 if (has_attached_progs < 0) {
356 p_err("can't query bpf programs attached to %s: %s",
357 path, strerror(errno));
358 goto exit_cgroup;
359 } else if (!has_attached_progs) {
360 ret = 0;
361 goto exit_cgroup;
362 }
363
364 if (json_output)
365 jsonw_start_array(json_wtr);
366 else if (query_flags & BPF_F_QUERY_EFFECTIVE)
367 printf("%-8s %-15s %-15s\n", "ID", "AttachType", "Name");
368 else
369 printf("%-8s %-15s %-15s %-15s\n", "ID", "AttachType",
370 "AttachFlags", "Name");
371
372 btf_vmlinux = libbpf_find_kernel_btf();
373 for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) {
374 /*
375 * Not all attach types may be supported, so it's expected,
376 * that some requests will fail.
377 * If we were able to get the show for at least one
378 * attach type, let's return 0.
379 */
380 if (show_bpf_progs(cgroup_fd, type, 0) == 0)
381 ret = 0;
382 }
383
384 if (json_output)
385 jsonw_end_array(json_wtr);
386
387 exit_cgroup:
388 close(cgroup_fd);
389 exit:
390 return ret;
391 }
392
393 /*
394 * To distinguish nftw() errors and do_show_tree_fn() errors
395 * and avoid duplicating error messages, let's return -2
396 * from do_show_tree_fn() in case of error.
397 */
398 #define NFTW_ERR -1
399 #define SHOW_TREE_FN_ERR -2
400 static int do_show_tree_fn(const char *fpath, const struct stat *sb,
401 int typeflag, struct FTW *ftw)
402 {
403 enum bpf_attach_type type;
404 int has_attached_progs;
405 int cgroup_fd;
406
407 if (typeflag != FTW_D)
408 return 0;
409
410 cgroup_fd = open(fpath, O_RDONLY);
411 if (cgroup_fd < 0) {
412 p_err("can't open cgroup %s: %s", fpath, strerror(errno));
413 return SHOW_TREE_FN_ERR;
414 }
415
416 has_attached_progs = cgroup_has_attached_progs(cgroup_fd);
417 if (has_attached_progs < 0) {
418 p_err("can't query bpf programs attached to %s: %s",
419 fpath, strerror(errno));
420 close(cgroup_fd);
421 return SHOW_TREE_FN_ERR;
422 } else if (!has_attached_progs) {
423 close(cgroup_fd);
424 return 0;
425 }
426
427 if (json_output) {
428 jsonw_start_object(json_wtr);
429 jsonw_string_field(json_wtr, "cgroup", fpath);
430 jsonw_name(json_wtr, "programs");
431 jsonw_start_array(json_wtr);
432 } else {
433 printf("%s\n", fpath);
434 }
435
436 btf_vmlinux = libbpf_find_kernel_btf();
437 for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++)
438 show_bpf_progs(cgroup_fd, type, ftw->level);
439
440 if (errno == EINVAL)
441 /* Last attach type does not support query.
442 * Do not report an error for this, especially because batch
443 * mode would stop processing commands.
444 */
445 errno = 0;
446
447 if (json_output) {
448 jsonw_end_array(json_wtr);
449 jsonw_end_object(json_wtr);
450 }
451
452 close(cgroup_fd);
453
454 return 0;
455 }
456
457 static char *find_cgroup_root(void)
458 {
459 struct mntent *mnt;
460 FILE *f;
461
462 f = fopen("/proc/mounts", "r");
463 if (f == NULL)
464 return NULL;
465
466 while ((mnt = getmntent(f))) {
467 if (strcmp(mnt->mnt_type, "cgroup2") == 0) {
468 fclose(f);
469 return strdup(mnt->mnt_dir);
470 }
471 }
472
473 fclose(f);
474 return NULL;
475 }
476
477 static int do_show_tree(int argc, char **argv)
478 {
479 char *cgroup_root, *cgroup_alloced = NULL;
480 int ret;
481
482 query_flags = 0;
483
484 if (!argc) {
485 cgroup_alloced = find_cgroup_root();
486 if (!cgroup_alloced) {
487 p_err("cgroup v2 isn't mounted");
488 return -1;
489 }
490 cgroup_root = cgroup_alloced;
491 } else {
492 cgroup_root = GET_ARG();
493
494 while (argc) {
495 if (is_prefix(*argv, "effective")) {
496 if (query_flags & BPF_F_QUERY_EFFECTIVE) {
497 p_err("duplicated argument: %s", *argv);
498 return -1;
499 }
500 query_flags |= BPF_F_QUERY_EFFECTIVE;
501 NEXT_ARG();
502 } else {
503 p_err("expected no more arguments, 'effective', got: '%s'?",
504 *argv);
505 return -1;
506 }
507 }
508 }
509
510 if (json_output)
511 jsonw_start_array(json_wtr);
512 else if (query_flags & BPF_F_QUERY_EFFECTIVE)
513 printf("%s\n"
514 "%-8s %-15s %-15s\n",
515 "CgroupPath",
516 "ID", "AttachType", "Name");
517 else
518 printf("%s\n"
519 "%-8s %-15s %-15s %-15s\n",
520 "CgroupPath",
521 "ID", "AttachType", "AttachFlags", "Name");
522
523 switch (nftw(cgroup_root, do_show_tree_fn, 1024, FTW_MOUNT)) {
524 case NFTW_ERR:
525 p_err("can't iterate over %s: %s", cgroup_root,
526 strerror(errno));
527 ret = -1;
528 break;
529 case SHOW_TREE_FN_ERR:
530 ret = -1;
531 break;
532 default:
533 ret = 0;
534 }
535
536 if (json_output)
537 jsonw_end_array(json_wtr);
538
539 free(cgroup_alloced);
540
541 return ret;
542 }
543
544 static int do_attach(int argc, char **argv)
545 {
546 enum bpf_attach_type attach_type;
547 int cgroup_fd, prog_fd;
548 int attach_flags = 0;
549 int ret = -1;
550 int i;
551
552 if (argc < 4) {
553 p_err("too few parameters for cgroup attach");
554 goto exit;
555 }
556
557 cgroup_fd = open(argv[0], O_RDONLY);
558 if (cgroup_fd < 0) {
559 p_err("can't open cgroup %s", argv[0]);
560 goto exit;
561 }
562
563 attach_type = parse_attach_type(argv[1]);
564 if (attach_type == __MAX_BPF_ATTACH_TYPE) {
565 p_err("invalid attach type");
566 goto exit_cgroup;
567 }
568
569 argc -= 2;
570 argv = &argv[2];
571 prog_fd = prog_parse_fd(&argc, &argv);
572 if (prog_fd < 0)
573 goto exit_cgroup;
574
575 for (i = 0; i < argc; i++) {
576 if (is_prefix(argv[i], "multi")) {
577 attach_flags |= BPF_F_ALLOW_MULTI;
578 } else if (is_prefix(argv[i], "override")) {
579 attach_flags |= BPF_F_ALLOW_OVERRIDE;
580 } else {
581 p_err("unknown option: %s", argv[i]);
582 goto exit_cgroup;
583 }
584 }
585
586 if (bpf_prog_attach(prog_fd, cgroup_fd, attach_type, attach_flags)) {
587 p_err("failed to attach program");
588 goto exit_prog;
589 }
590
591 if (json_output)
592 jsonw_null(json_wtr);
593
594 ret = 0;
595
596 exit_prog:
597 close(prog_fd);
598 exit_cgroup:
599 close(cgroup_fd);
600 exit:
601 return ret;
602 }
603
604 static int do_detach(int argc, char **argv)
605 {
606 enum bpf_attach_type attach_type;
607 int prog_fd, cgroup_fd;
608 int ret = -1;
609
610 if (argc < 4) {
611 p_err("too few parameters for cgroup detach");
612 goto exit;
613 }
614
615 cgroup_fd = open(argv[0], O_RDONLY);
616 if (cgroup_fd < 0) {
617 p_err("can't open cgroup %s", argv[0]);
618 goto exit;
619 }
620
621 attach_type = parse_attach_type(argv[1]);
622 if (attach_type == __MAX_BPF_ATTACH_TYPE) {
623 p_err("invalid attach type");
624 goto exit_cgroup;
625 }
626
627 argc -= 2;
628 argv = &argv[2];
629 prog_fd = prog_parse_fd(&argc, &argv);
630 if (prog_fd < 0)
631 goto exit_cgroup;
632
633 if (bpf_prog_detach2(prog_fd, cgroup_fd, attach_type)) {
634 p_err("failed to detach program");
635 goto exit_prog;
636 }
637
638 if (json_output)
639 jsonw_null(json_wtr);
640
641 ret = 0;
642
643 exit_prog:
644 close(prog_fd);
645 exit_cgroup:
646 close(cgroup_fd);
647 exit:
648 return ret;
649 }
650
651 static int do_help(int argc, char **argv)
652 {
653 if (json_output) {
654 jsonw_null(json_wtr);
655 return 0;
656 }
657
658 fprintf(stderr,
659 "Usage: %1$s %2$s { show | list } CGROUP [**effective**]\n"
660 " %1$s %2$s tree [CGROUP_ROOT] [**effective**]\n"
661 " %1$s %2$s attach CGROUP ATTACH_TYPE PROG [ATTACH_FLAGS]\n"
662 " %1$s %2$s detach CGROUP ATTACH_TYPE PROG\n"
663 " %1$s %2$s help\n"
664 "\n"
665 HELP_SPEC_ATTACH_TYPES "\n"
666 " " HELP_SPEC_ATTACH_FLAGS "\n"
667 " " HELP_SPEC_PROGRAM "\n"
668 " " HELP_SPEC_OPTIONS " |\n"
669 " {-f|--bpffs} }\n"
670 "",
671 bin_name, argv[-2]);
672
673 return 0;
674 }
675
676 static const struct cmd cmds[] = {
677 { "show", do_show },
678 { "list", do_show },
679 { "tree", do_show_tree },
680 { "attach", do_attach },
681 { "detach", do_detach },
682 { "help", do_help },
683 { 0 }
684 };
685
686 int do_cgroup(int argc, char **argv)
687 {
688 return cmd_select(cmds, argc, argv, do_help);
689 }
690
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