1
2
3
4#include <errno.h>
5#include <fcntl.h>
6#include <linux/err.h>
7#include <stdbool.h>
8#include <stdio.h>
9#include <string.h>
10#include <unistd.h>
11#include <bpf/bpf.h>
12#include <bpf/btf.h>
13#include <bpf/libbpf.h>
14#include <linux/btf.h>
15#include <linux/hashtable.h>
16#include <sys/types.h>
17#include <sys/stat.h>
18
19#include "json_writer.h"
20#include "main.h"
21
22static const char * const btf_kind_str[NR_BTF_KINDS] = {
23 [BTF_KIND_UNKN] = "UNKNOWN",
24 [BTF_KIND_INT] = "INT",
25 [BTF_KIND_PTR] = "PTR",
26 [BTF_KIND_ARRAY] = "ARRAY",
27 [BTF_KIND_STRUCT] = "STRUCT",
28 [BTF_KIND_UNION] = "UNION",
29 [BTF_KIND_ENUM] = "ENUM",
30 [BTF_KIND_FWD] = "FWD",
31 [BTF_KIND_TYPEDEF] = "TYPEDEF",
32 [BTF_KIND_VOLATILE] = "VOLATILE",
33 [BTF_KIND_CONST] = "CONST",
34 [BTF_KIND_RESTRICT] = "RESTRICT",
35 [BTF_KIND_FUNC] = "FUNC",
36 [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
37 [BTF_KIND_VAR] = "VAR",
38 [BTF_KIND_DATASEC] = "DATASEC",
39};
40
41struct btf_attach_table {
42 DECLARE_HASHTABLE(table, 16);
43};
44
45struct btf_attach_point {
46 __u32 obj_id;
47 __u32 btf_id;
48 struct hlist_node hash;
49};
50
51static const char *btf_int_enc_str(__u8 encoding)
52{
53 switch (encoding) {
54 case 0:
55 return "(none)";
56 case BTF_INT_SIGNED:
57 return "SIGNED";
58 case BTF_INT_CHAR:
59 return "CHAR";
60 case BTF_INT_BOOL:
61 return "BOOL";
62 default:
63 return "UNKN";
64 }
65}
66
67static const char *btf_var_linkage_str(__u32 linkage)
68{
69 switch (linkage) {
70 case BTF_VAR_STATIC:
71 return "static";
72 case BTF_VAR_GLOBAL_ALLOCATED:
73 return "global-alloc";
74 default:
75 return "(unknown)";
76 }
77}
78
79static const char *btf_func_linkage_str(const struct btf_type *t)
80{
81 switch (btf_vlen(t)) {
82 case BTF_FUNC_STATIC:
83 return "static";
84 case BTF_FUNC_GLOBAL:
85 return "global";
86 case BTF_FUNC_EXTERN:
87 return "extern";
88 default:
89 return "(unknown)";
90 }
91}
92
93static const char *btf_str(const struct btf *btf, __u32 off)
94{
95 if (!off)
96 return "(anon)";
97 return btf__name_by_offset(btf, off) ? : "(invalid)";
98}
99
100static int dump_btf_type(const struct btf *btf, __u32 id,
101 const struct btf_type *t)
102{
103 json_writer_t *w = json_wtr;
104 int kind, safe_kind;
105
106 kind = BTF_INFO_KIND(t->info);
107 safe_kind = kind <= BTF_KIND_MAX ? kind : BTF_KIND_UNKN;
108
109 if (json_output) {
110 jsonw_start_object(w);
111 jsonw_uint_field(w, "id", id);
112 jsonw_string_field(w, "kind", btf_kind_str[safe_kind]);
113 jsonw_string_field(w, "name", btf_str(btf, t->name_off));
114 } else {
115 printf("[%u] %s '%s'", id, btf_kind_str[safe_kind],
116 btf_str(btf, t->name_off));
117 }
118
119 switch (BTF_INFO_KIND(t->info)) {
120 case BTF_KIND_INT: {
121 __u32 v = *(__u32 *)(t + 1);
122 const char *enc;
123
124 enc = btf_int_enc_str(BTF_INT_ENCODING(v));
125
126 if (json_output) {
127 jsonw_uint_field(w, "size", t->size);
128 jsonw_uint_field(w, "bits_offset", BTF_INT_OFFSET(v));
129 jsonw_uint_field(w, "nr_bits", BTF_INT_BITS(v));
130 jsonw_string_field(w, "encoding", enc);
131 } else {
132 printf(" size=%u bits_offset=%u nr_bits=%u encoding=%s",
133 t->size, BTF_INT_OFFSET(v), BTF_INT_BITS(v),
134 enc);
135 }
136 break;
137 }
138 case BTF_KIND_PTR:
139 case BTF_KIND_CONST:
140 case BTF_KIND_VOLATILE:
141 case BTF_KIND_RESTRICT:
142 case BTF_KIND_TYPEDEF:
143 if (json_output)
144 jsonw_uint_field(w, "type_id", t->type);
145 else
146 printf(" type_id=%u", t->type);
147 break;
148 case BTF_KIND_ARRAY: {
149 const struct btf_array *arr = (const void *)(t + 1);
150
151 if (json_output) {
152 jsonw_uint_field(w, "type_id", arr->type);
153 jsonw_uint_field(w, "index_type_id", arr->index_type);
154 jsonw_uint_field(w, "nr_elems", arr->nelems);
155 } else {
156 printf(" type_id=%u index_type_id=%u nr_elems=%u",
157 arr->type, arr->index_type, arr->nelems);
158 }
159 break;
160 }
161 case BTF_KIND_STRUCT:
162 case BTF_KIND_UNION: {
163 const struct btf_member *m = (const void *)(t + 1);
164 __u16 vlen = BTF_INFO_VLEN(t->info);
165 int i;
166
167 if (json_output) {
168 jsonw_uint_field(w, "size", t->size);
169 jsonw_uint_field(w, "vlen", vlen);
170 jsonw_name(w, "members");
171 jsonw_start_array(w);
172 } else {
173 printf(" size=%u vlen=%u", t->size, vlen);
174 }
175 for (i = 0; i < vlen; i++, m++) {
176 const char *name = btf_str(btf, m->name_off);
177 __u32 bit_off, bit_sz;
178
179 if (BTF_INFO_KFLAG(t->info)) {
180 bit_off = BTF_MEMBER_BIT_OFFSET(m->offset);
181 bit_sz = BTF_MEMBER_BITFIELD_SIZE(m->offset);
182 } else {
183 bit_off = m->offset;
184 bit_sz = 0;
185 }
186
187 if (json_output) {
188 jsonw_start_object(w);
189 jsonw_string_field(w, "name", name);
190 jsonw_uint_field(w, "type_id", m->type);
191 jsonw_uint_field(w, "bits_offset", bit_off);
192 if (bit_sz) {
193 jsonw_uint_field(w, "bitfield_size",
194 bit_sz);
195 }
196 jsonw_end_object(w);
197 } else {
198 printf("\n\t'%s' type_id=%u bits_offset=%u",
199 name, m->type, bit_off);
200 if (bit_sz)
201 printf(" bitfield_size=%u", bit_sz);
202 }
203 }
204 if (json_output)
205 jsonw_end_array(w);
206 break;
207 }
208 case BTF_KIND_ENUM: {
209 const struct btf_enum *v = (const void *)(t + 1);
210 __u16 vlen = BTF_INFO_VLEN(t->info);
211 int i;
212
213 if (json_output) {
214 jsonw_uint_field(w, "size", t->size);
215 jsonw_uint_field(w, "vlen", vlen);
216 jsonw_name(w, "values");
217 jsonw_start_array(w);
218 } else {
219 printf(" size=%u vlen=%u", t->size, vlen);
220 }
221 for (i = 0; i < vlen; i++, v++) {
222 const char *name = btf_str(btf, v->name_off);
223
224 if (json_output) {
225 jsonw_start_object(w);
226 jsonw_string_field(w, "name", name);
227 jsonw_uint_field(w, "val", v->val);
228 jsonw_end_object(w);
229 } else {
230 printf("\n\t'%s' val=%u", name, v->val);
231 }
232 }
233 if (json_output)
234 jsonw_end_array(w);
235 break;
236 }
237 case BTF_KIND_FWD: {
238 const char *fwd_kind = BTF_INFO_KFLAG(t->info) ? "union"
239 : "struct";
240
241 if (json_output)
242 jsonw_string_field(w, "fwd_kind", fwd_kind);
243 else
244 printf(" fwd_kind=%s", fwd_kind);
245 break;
246 }
247 case BTF_KIND_FUNC: {
248 const char *linkage = btf_func_linkage_str(t);
249
250 if (json_output) {
251 jsonw_uint_field(w, "type_id", t->type);
252 jsonw_string_field(w, "linkage", linkage);
253 } else {
254 printf(" type_id=%u linkage=%s", t->type, linkage);
255 }
256 break;
257 }
258 case BTF_KIND_FUNC_PROTO: {
259 const struct btf_param *p = (const void *)(t + 1);
260 __u16 vlen = BTF_INFO_VLEN(t->info);
261 int i;
262
263 if (json_output) {
264 jsonw_uint_field(w, "ret_type_id", t->type);
265 jsonw_uint_field(w, "vlen", vlen);
266 jsonw_name(w, "params");
267 jsonw_start_array(w);
268 } else {
269 printf(" ret_type_id=%u vlen=%u", t->type, vlen);
270 }
271 for (i = 0; i < vlen; i++, p++) {
272 const char *name = btf_str(btf, p->name_off);
273
274 if (json_output) {
275 jsonw_start_object(w);
276 jsonw_string_field(w, "name", name);
277 jsonw_uint_field(w, "type_id", p->type);
278 jsonw_end_object(w);
279 } else {
280 printf("\n\t'%s' type_id=%u", name, p->type);
281 }
282 }
283 if (json_output)
284 jsonw_end_array(w);
285 break;
286 }
287 case BTF_KIND_VAR: {
288 const struct btf_var *v = (const void *)(t + 1);
289 const char *linkage;
290
291 linkage = btf_var_linkage_str(v->linkage);
292
293 if (json_output) {
294 jsonw_uint_field(w, "type_id", t->type);
295 jsonw_string_field(w, "linkage", linkage);
296 } else {
297 printf(" type_id=%u, linkage=%s", t->type, linkage);
298 }
299 break;
300 }
301 case BTF_KIND_DATASEC: {
302 const struct btf_var_secinfo *v = (const void *)(t+1);
303 __u16 vlen = BTF_INFO_VLEN(t->info);
304 int i;
305
306 if (json_output) {
307 jsonw_uint_field(w, "size", t->size);
308 jsonw_uint_field(w, "vlen", vlen);
309 jsonw_name(w, "vars");
310 jsonw_start_array(w);
311 } else {
312 printf(" size=%u vlen=%u", t->size, vlen);
313 }
314 for (i = 0; i < vlen; i++, v++) {
315 if (json_output) {
316 jsonw_start_object(w);
317 jsonw_uint_field(w, "type_id", v->type);
318 jsonw_uint_field(w, "offset", v->offset);
319 jsonw_uint_field(w, "size", v->size);
320 jsonw_end_object(w);
321 } else {
322 printf("\n\ttype_id=%u offset=%u size=%u",
323 v->type, v->offset, v->size);
324 }
325 }
326 if (json_output)
327 jsonw_end_array(w);
328 break;
329 }
330 default:
331 break;
332 }
333
334 if (json_output)
335 jsonw_end_object(json_wtr);
336 else
337 printf("\n");
338
339 return 0;
340}
341
342static int dump_btf_raw(const struct btf *btf,
343 __u32 *root_type_ids, int root_type_cnt)
344{
345 const struct btf_type *t;
346 int i;
347
348 if (json_output) {
349 jsonw_start_object(json_wtr);
350 jsonw_name(json_wtr, "types");
351 jsonw_start_array(json_wtr);
352 }
353
354 if (root_type_cnt) {
355 for (i = 0; i < root_type_cnt; i++) {
356 t = btf__type_by_id(btf, root_type_ids[i]);
357 dump_btf_type(btf, root_type_ids[i], t);
358 }
359 } else {
360 int cnt = btf__get_nr_types(btf);
361
362 for (i = 1; i <= cnt; i++) {
363 t = btf__type_by_id(btf, i);
364 dump_btf_type(btf, i, t);
365 }
366 }
367
368 if (json_output) {
369 jsonw_end_array(json_wtr);
370 jsonw_end_object(json_wtr);
371 }
372 return 0;
373}
374
375static void __printf(2, 0) btf_dump_printf(void *ctx,
376 const char *fmt, va_list args)
377{
378 vfprintf(stdout, fmt, args);
379}
380
381static int dump_btf_c(const struct btf *btf,
382 __u32 *root_type_ids, int root_type_cnt)
383{
384 struct btf_dump *d;
385 int err = 0, i;
386
387 d = btf_dump__new(btf, NULL, NULL, btf_dump_printf);
388 if (IS_ERR(d))
389 return PTR_ERR(d);
390
391 printf("#ifndef __VMLINUX_H__\n");
392 printf("#define __VMLINUX_H__\n");
393 printf("\n");
394 printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
395 printf("#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)\n");
396 printf("#endif\n\n");
397
398 if (root_type_cnt) {
399 for (i = 0; i < root_type_cnt; i++) {
400 err = btf_dump__dump_type(d, root_type_ids[i]);
401 if (err)
402 goto done;
403 }
404 } else {
405 int cnt = btf__get_nr_types(btf);
406
407 for (i = 1; i <= cnt; i++) {
408 err = btf_dump__dump_type(d, i);
409 if (err)
410 goto done;
411 }
412 }
413
414 printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
415 printf("#pragma clang attribute pop\n");
416 printf("#endif\n");
417 printf("\n");
418 printf("#endif /* __VMLINUX_H__ */\n");
419
420done:
421 btf_dump__free(d);
422 return err;
423}
424
425static struct btf *btf__parse_raw(const char *file)
426{
427 struct btf *btf;
428 struct stat st;
429 __u8 *buf;
430 FILE *f;
431
432 if (stat(file, &st))
433 return NULL;
434
435 f = fopen(file, "rb");
436 if (!f)
437 return NULL;
438
439 buf = malloc(st.st_size);
440 if (!buf) {
441 btf = ERR_PTR(-ENOMEM);
442 goto exit_close;
443 }
444
445 if ((size_t) st.st_size != fread(buf, 1, st.st_size, f)) {
446 btf = ERR_PTR(-EINVAL);
447 goto exit_free;
448 }
449
450 btf = btf__new(buf, st.st_size);
451
452exit_free:
453 free(buf);
454exit_close:
455 fclose(f);
456 return btf;
457}
458
459static bool is_btf_raw(const char *file)
460{
461 __u16 magic = 0;
462 int fd, nb_read;
463
464 fd = open(file, O_RDONLY);
465 if (fd < 0)
466 return false;
467
468 nb_read = read(fd, &magic, sizeof(magic));
469 close(fd);
470 return nb_read == sizeof(magic) && magic == BTF_MAGIC;
471}
472
473static int do_dump(int argc, char **argv)
474{
475 struct btf *btf = NULL;
476 __u32 root_type_ids[2];
477 int root_type_cnt = 0;
478 bool dump_c = false;
479 __u32 btf_id = -1;
480 const char *src;
481 int fd = -1;
482 int err;
483
484 if (!REQ_ARGS(2)) {
485 usage();
486 return -1;
487 }
488 src = GET_ARG();
489
490 if (is_prefix(src, "map")) {
491 struct bpf_map_info info = {};
492 __u32 len = sizeof(info);
493
494 if (!REQ_ARGS(2)) {
495 usage();
496 return -1;
497 }
498
499 fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
500 if (fd < 0)
501 return -1;
502
503 btf_id = info.btf_id;
504 if (argc && is_prefix(*argv, "key")) {
505 root_type_ids[root_type_cnt++] = info.btf_key_type_id;
506 NEXT_ARG();
507 } else if (argc && is_prefix(*argv, "value")) {
508 root_type_ids[root_type_cnt++] = info.btf_value_type_id;
509 NEXT_ARG();
510 } else if (argc && is_prefix(*argv, "all")) {
511 NEXT_ARG();
512 } else if (argc && is_prefix(*argv, "kv")) {
513 root_type_ids[root_type_cnt++] = info.btf_key_type_id;
514 root_type_ids[root_type_cnt++] = info.btf_value_type_id;
515 NEXT_ARG();
516 } else {
517 root_type_ids[root_type_cnt++] = info.btf_key_type_id;
518 root_type_ids[root_type_cnt++] = info.btf_value_type_id;
519 }
520 } else if (is_prefix(src, "prog")) {
521 struct bpf_prog_info info = {};
522 __u32 len = sizeof(info);
523
524 if (!REQ_ARGS(2)) {
525 usage();
526 return -1;
527 }
528
529 fd = prog_parse_fd(&argc, &argv);
530 if (fd < 0)
531 return -1;
532
533 err = bpf_obj_get_info_by_fd(fd, &info, &len);
534 if (err) {
535 p_err("can't get prog info: %s", strerror(errno));
536 goto done;
537 }
538
539 btf_id = info.btf_id;
540 } else if (is_prefix(src, "id")) {
541 char *endptr;
542
543 btf_id = strtoul(*argv, &endptr, 0);
544 if (*endptr) {
545 p_err("can't parse %s as ID", *argv);
546 return -1;
547 }
548 NEXT_ARG();
549 } else if (is_prefix(src, "file")) {
550 if (is_btf_raw(*argv))
551 btf = btf__parse_raw(*argv);
552 else
553 btf = btf__parse_elf(*argv, NULL);
554
555 if (IS_ERR(btf)) {
556 err = -PTR_ERR(btf);
557 btf = NULL;
558 p_err("failed to load BTF from %s: %s",
559 *argv, strerror(err));
560 goto done;
561 }
562 NEXT_ARG();
563 } else {
564 err = -1;
565 p_err("unrecognized BTF source specifier: '%s'", src);
566 goto done;
567 }
568
569 while (argc) {
570 if (is_prefix(*argv, "format")) {
571 NEXT_ARG();
572 if (argc < 1) {
573 p_err("expecting value for 'format' option\n");
574 goto done;
575 }
576 if (strcmp(*argv, "c") == 0) {
577 dump_c = true;
578 } else if (strcmp(*argv, "raw") == 0) {
579 dump_c = false;
580 } else {
581 p_err("unrecognized format specifier: '%s', possible values: raw, c",
582 *argv);
583 goto done;
584 }
585 NEXT_ARG();
586 } else {
587 p_err("unrecognized option: '%s'", *argv);
588 goto done;
589 }
590 }
591
592 if (!btf) {
593 err = btf__get_from_id(btf_id, &btf);
594 if (err) {
595 p_err("get btf by id (%u): %s", btf_id, strerror(err));
596 goto done;
597 }
598 if (!btf) {
599 err = ENOENT;
600 p_err("can't find btf with ID (%u)", btf_id);
601 goto done;
602 }
603 }
604
605 if (dump_c) {
606 if (json_output) {
607 p_err("JSON output for C-syntax dump is not supported");
608 err = -ENOTSUP;
609 goto done;
610 }
611 err = dump_btf_c(btf, root_type_ids, root_type_cnt);
612 } else {
613 err = dump_btf_raw(btf, root_type_ids, root_type_cnt);
614 }
615
616done:
617 close(fd);
618 btf__free(btf);
619 return err;
620}
621
622static int btf_parse_fd(int *argc, char ***argv)
623{
624 unsigned int id;
625 char *endptr;
626 int fd;
627
628 if (!is_prefix(*argv[0], "id")) {
629 p_err("expected 'id', got: '%s'?", **argv);
630 return -1;
631 }
632 NEXT_ARGP();
633
634 id = strtoul(**argv, &endptr, 0);
635 if (*endptr) {
636 p_err("can't parse %s as ID", **argv);
637 return -1;
638 }
639 NEXT_ARGP();
640
641 fd = bpf_btf_get_fd_by_id(id);
642 if (fd < 0)
643 p_err("can't get BTF object by id (%u): %s",
644 id, strerror(errno));
645
646 return fd;
647}
648
649static void delete_btf_table(struct btf_attach_table *tab)
650{
651 struct btf_attach_point *obj;
652 struct hlist_node *tmp;
653
654 unsigned int bkt;
655
656 hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
657 hash_del(&obj->hash);
658 free(obj);
659 }
660}
661
662static int
663build_btf_type_table(struct btf_attach_table *tab, enum bpf_obj_type type,
664 void *info, __u32 *len)
665{
666 static const char * const names[] = {
667 [BPF_OBJ_UNKNOWN] = "unknown",
668 [BPF_OBJ_PROG] = "prog",
669 [BPF_OBJ_MAP] = "map",
670 };
671 struct btf_attach_point *obj_node;
672 __u32 btf_id, id = 0;
673 int err;
674 int fd;
675
676 while (true) {
677 switch (type) {
678 case BPF_OBJ_PROG:
679 err = bpf_prog_get_next_id(id, &id);
680 break;
681 case BPF_OBJ_MAP:
682 err = bpf_map_get_next_id(id, &id);
683 break;
684 default:
685 err = -1;
686 p_err("unexpected object type: %d", type);
687 goto err_free;
688 }
689 if (err) {
690 if (errno == ENOENT) {
691 err = 0;
692 break;
693 }
694 p_err("can't get next %s: %s%s", names[type],
695 strerror(errno),
696 errno == EINVAL ? " -- kernel too old?" : "");
697 goto err_free;
698 }
699
700 switch (type) {
701 case BPF_OBJ_PROG:
702 fd = bpf_prog_get_fd_by_id(id);
703 break;
704 case BPF_OBJ_MAP:
705 fd = bpf_map_get_fd_by_id(id);
706 break;
707 default:
708 err = -1;
709 p_err("unexpected object type: %d", type);
710 goto err_free;
711 }
712 if (fd < 0) {
713 if (errno == ENOENT)
714 continue;
715 p_err("can't get %s by id (%u): %s", names[type], id,
716 strerror(errno));
717 err = -1;
718 goto err_free;
719 }
720
721 memset(info, 0, *len);
722 err = bpf_obj_get_info_by_fd(fd, info, len);
723 close(fd);
724 if (err) {
725 p_err("can't get %s info: %s", names[type],
726 strerror(errno));
727 goto err_free;
728 }
729
730 switch (type) {
731 case BPF_OBJ_PROG:
732 btf_id = ((struct bpf_prog_info *)info)->btf_id;
733 break;
734 case BPF_OBJ_MAP:
735 btf_id = ((struct bpf_map_info *)info)->btf_id;
736 break;
737 default:
738 err = -1;
739 p_err("unexpected object type: %d", type);
740 goto err_free;
741 }
742 if (!btf_id)
743 continue;
744
745 obj_node = calloc(1, sizeof(*obj_node));
746 if (!obj_node) {
747 p_err("failed to allocate memory: %s", strerror(errno));
748 goto err_free;
749 }
750
751 obj_node->obj_id = id;
752 obj_node->btf_id = btf_id;
753 hash_add(tab->table, &obj_node->hash, obj_node->btf_id);
754 }
755
756 return 0;
757
758err_free:
759 delete_btf_table(tab);
760 return err;
761}
762
763static int
764build_btf_tables(struct btf_attach_table *btf_prog_table,
765 struct btf_attach_table *btf_map_table)
766{
767 struct bpf_prog_info prog_info;
768 __u32 prog_len = sizeof(prog_info);
769 struct bpf_map_info map_info;
770 __u32 map_len = sizeof(map_info);
771 int err = 0;
772
773 err = build_btf_type_table(btf_prog_table, BPF_OBJ_PROG, &prog_info,
774 &prog_len);
775 if (err)
776 return err;
777
778 err = build_btf_type_table(btf_map_table, BPF_OBJ_MAP, &map_info,
779 &map_len);
780 if (err) {
781 delete_btf_table(btf_prog_table);
782 return err;
783 }
784
785 return 0;
786}
787
788static void
789show_btf_plain(struct bpf_btf_info *info, int fd,
790 struct btf_attach_table *btf_prog_table,
791 struct btf_attach_table *btf_map_table)
792{
793 struct btf_attach_point *obj;
794 int n;
795
796 printf("%u: ", info->id);
797 printf("size %uB", info->btf_size);
798
799 n = 0;
800 hash_for_each_possible(btf_prog_table->table, obj, hash, info->id) {
801 if (obj->btf_id == info->id)
802 printf("%s%u", n++ == 0 ? " prog_ids " : ",",
803 obj->obj_id);
804 }
805
806 n = 0;
807 hash_for_each_possible(btf_map_table->table, obj, hash, info->id) {
808 if (obj->btf_id == info->id)
809 printf("%s%u", n++ == 0 ? " map_ids " : ",",
810 obj->obj_id);
811 }
812
813 printf("\n");
814}
815
816static void
817show_btf_json(struct bpf_btf_info *info, int fd,
818 struct btf_attach_table *btf_prog_table,
819 struct btf_attach_table *btf_map_table)
820{
821 struct btf_attach_point *obj;
822
823 jsonw_start_object(json_wtr);
824 jsonw_uint_field(json_wtr, "id", info->id);
825 jsonw_uint_field(json_wtr, "size", info->btf_size);
826
827 jsonw_name(json_wtr, "prog_ids");
828 jsonw_start_array(json_wtr);
829 hash_for_each_possible(btf_prog_table->table, obj, hash,
830 info->id) {
831 if (obj->btf_id == info->id)
832 jsonw_uint(json_wtr, obj->obj_id);
833 }
834 jsonw_end_array(json_wtr);
835
836 jsonw_name(json_wtr, "map_ids");
837 jsonw_start_array(json_wtr);
838 hash_for_each_possible(btf_map_table->table, obj, hash,
839 info->id) {
840 if (obj->btf_id == info->id)
841 jsonw_uint(json_wtr, obj->obj_id);
842 }
843 jsonw_end_array(json_wtr);
844 jsonw_end_object(json_wtr);
845}
846
847static int
848show_btf(int fd, struct btf_attach_table *btf_prog_table,
849 struct btf_attach_table *btf_map_table)
850{
851 struct bpf_btf_info info = {};
852 __u32 len = sizeof(info);
853 int err;
854
855 err = bpf_obj_get_info_by_fd(fd, &info, &len);
856 if (err) {
857 p_err("can't get BTF object info: %s", strerror(errno));
858 return -1;
859 }
860
861 if (json_output)
862 show_btf_json(&info, fd, btf_prog_table, btf_map_table);
863 else
864 show_btf_plain(&info, fd, btf_prog_table, btf_map_table);
865
866 return 0;
867}
868
869static int do_show(int argc, char **argv)
870{
871 struct btf_attach_table btf_prog_table;
872 struct btf_attach_table btf_map_table;
873 int err, fd = -1;
874 __u32 id = 0;
875
876 if (argc == 2) {
877 fd = btf_parse_fd(&argc, &argv);
878 if (fd < 0)
879 return -1;
880 }
881
882 if (argc) {
883 if (fd >= 0)
884 close(fd);
885 return BAD_ARG();
886 }
887
888 hash_init(btf_prog_table.table);
889 hash_init(btf_map_table.table);
890 err = build_btf_tables(&btf_prog_table, &btf_map_table);
891 if (err) {
892 if (fd >= 0)
893 close(fd);
894 return err;
895 }
896
897 if (fd >= 0) {
898 err = show_btf(fd, &btf_prog_table, &btf_map_table);
899 close(fd);
900 goto exit_free;
901 }
902
903 if (json_output)
904 jsonw_start_array(json_wtr);
905
906 while (true) {
907 err = bpf_btf_get_next_id(id, &id);
908 if (err) {
909 if (errno == ENOENT) {
910 err = 0;
911 break;
912 }
913 p_err("can't get next BTF object: %s%s",
914 strerror(errno),
915 errno == EINVAL ? " -- kernel too old?" : "");
916 err = -1;
917 break;
918 }
919
920 fd = bpf_btf_get_fd_by_id(id);
921 if (fd < 0) {
922 if (errno == ENOENT)
923 continue;
924 p_err("can't get BTF object by id (%u): %s",
925 id, strerror(errno));
926 err = -1;
927 break;
928 }
929
930 err = show_btf(fd, &btf_prog_table, &btf_map_table);
931 close(fd);
932 if (err)
933 break;
934 }
935
936 if (json_output)
937 jsonw_end_array(json_wtr);
938
939exit_free:
940 delete_btf_table(&btf_prog_table);
941 delete_btf_table(&btf_map_table);
942
943 return err;
944}
945
946static int do_help(int argc, char **argv)
947{
948 if (json_output) {
949 jsonw_null(json_wtr);
950 return 0;
951 }
952
953 fprintf(stderr,
954 "Usage: %1$s %2$s { show | list } [id BTF_ID]\n"
955 " %1$s %2$s dump BTF_SRC [format FORMAT]\n"
956 " %1$s %2$s help\n"
957 "\n"
958 " BTF_SRC := { id BTF_ID | prog PROG | map MAP [{key | value | kv | all}] | file FILE }\n"
959 " FORMAT := { raw | c }\n"
960 " " HELP_SPEC_MAP "\n"
961 " " HELP_SPEC_PROGRAM "\n"
962 " " HELP_SPEC_OPTIONS "\n"
963 "",
964 bin_name, "btf");
965
966 return 0;
967}
968
969static const struct cmd cmds[] = {
970 { "show", do_show },
971 { "list", do_show },
972 { "help", do_help },
973 { "dump", do_dump },
974 { 0 }
975};
976
977int do_btf(int argc, char **argv)
978{
979 return cmd_select(cmds, argc, argv, do_help);
980}
981
