xref: /openbmc/linux/tools/bpf/bpftool/map.c (revision 0760aad038b5a032c31ea124feed63d88627d2f1)
1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2017-2018 Netronome Systems, Inc. */
3 
4 #include <assert.h>
5 #include <errno.h>
6 #include <fcntl.h>
7 #include <linux/err.h>
8 #include <linux/kernel.h>
9 #include <net/if.h>
10 #include <stdbool.h>
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <unistd.h>
15 #include <sys/types.h>
16 #include <sys/stat.h>
17 
18 #include <bpf/bpf.h>
19 #include <bpf/btf.h>
20 
21 #include "json_writer.h"
22 #include "main.h"
23 
24 const char * const map_type_name[] = {
25 	[BPF_MAP_TYPE_UNSPEC]			= "unspec",
26 	[BPF_MAP_TYPE_HASH]			= "hash",
27 	[BPF_MAP_TYPE_ARRAY]			= "array",
28 	[BPF_MAP_TYPE_PROG_ARRAY]		= "prog_array",
29 	[BPF_MAP_TYPE_PERF_EVENT_ARRAY]		= "perf_event_array",
30 	[BPF_MAP_TYPE_PERCPU_HASH]		= "percpu_hash",
31 	[BPF_MAP_TYPE_PERCPU_ARRAY]		= "percpu_array",
32 	[BPF_MAP_TYPE_STACK_TRACE]		= "stack_trace",
33 	[BPF_MAP_TYPE_CGROUP_ARRAY]		= "cgroup_array",
34 	[BPF_MAP_TYPE_LRU_HASH]			= "lru_hash",
35 	[BPF_MAP_TYPE_LRU_PERCPU_HASH]		= "lru_percpu_hash",
36 	[BPF_MAP_TYPE_LPM_TRIE]			= "lpm_trie",
37 	[BPF_MAP_TYPE_ARRAY_OF_MAPS]		= "array_of_maps",
38 	[BPF_MAP_TYPE_HASH_OF_MAPS]		= "hash_of_maps",
39 	[BPF_MAP_TYPE_DEVMAP]			= "devmap",
40 	[BPF_MAP_TYPE_DEVMAP_HASH]		= "devmap_hash",
41 	[BPF_MAP_TYPE_SOCKMAP]			= "sockmap",
42 	[BPF_MAP_TYPE_CPUMAP]			= "cpumap",
43 	[BPF_MAP_TYPE_XSKMAP]			= "xskmap",
44 	[BPF_MAP_TYPE_SOCKHASH]			= "sockhash",
45 	[BPF_MAP_TYPE_CGROUP_STORAGE]		= "cgroup_storage",
46 	[BPF_MAP_TYPE_REUSEPORT_SOCKARRAY]	= "reuseport_sockarray",
47 	[BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE]	= "percpu_cgroup_storage",
48 	[BPF_MAP_TYPE_QUEUE]			= "queue",
49 	[BPF_MAP_TYPE_STACK]			= "stack",
50 	[BPF_MAP_TYPE_SK_STORAGE]		= "sk_storage",
51 	[BPF_MAP_TYPE_STRUCT_OPS]		= "struct_ops",
52 	[BPF_MAP_TYPE_RINGBUF]			= "ringbuf",
53 	[BPF_MAP_TYPE_INODE_STORAGE]		= "inode_storage",
54 };
55 
56 const size_t map_type_name_size = ARRAY_SIZE(map_type_name);
57 
58 static bool map_is_per_cpu(__u32 type)
59 {
60 	return type == BPF_MAP_TYPE_PERCPU_HASH ||
61 	       type == BPF_MAP_TYPE_PERCPU_ARRAY ||
62 	       type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
63 	       type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE;
64 }
65 
66 static bool map_is_map_of_maps(__u32 type)
67 {
68 	return type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
69 	       type == BPF_MAP_TYPE_HASH_OF_MAPS;
70 }
71 
72 static bool map_is_map_of_progs(__u32 type)
73 {
74 	return type == BPF_MAP_TYPE_PROG_ARRAY;
75 }
76 
77 static int map_type_from_str(const char *type)
78 {
79 	unsigned int i;
80 
81 	for (i = 0; i < ARRAY_SIZE(map_type_name); i++)
82 		/* Don't allow prefixing in case of possible future shadowing */
83 		if (map_type_name[i] && !strcmp(map_type_name[i], type))
84 			return i;
85 	return -1;
86 }
87 
88 static void *alloc_value(struct bpf_map_info *info)
89 {
90 	if (map_is_per_cpu(info->type))
91 		return malloc(round_up(info->value_size, 8) *
92 			      get_possible_cpus());
93 	else
94 		return malloc(info->value_size);
95 }
96 
97 static int do_dump_btf(const struct btf_dumper *d,
98 		       struct bpf_map_info *map_info, void *key,
99 		       void *value)
100 {
101 	__u32 value_id;
102 	int ret;
103 
104 	/* start of key-value pair */
105 	jsonw_start_object(d->jw);
106 
107 	if (map_info->btf_key_type_id) {
108 		jsonw_name(d->jw, "key");
109 
110 		ret = btf_dumper_type(d, map_info->btf_key_type_id, key);
111 		if (ret)
112 			goto err_end_obj;
113 	}
114 
115 	value_id = map_info->btf_vmlinux_value_type_id ?
116 		: map_info->btf_value_type_id;
117 
118 	if (!map_is_per_cpu(map_info->type)) {
119 		jsonw_name(d->jw, "value");
120 		ret = btf_dumper_type(d, value_id, value);
121 	} else {
122 		unsigned int i, n, step;
123 
124 		jsonw_name(d->jw, "values");
125 		jsonw_start_array(d->jw);
126 		n = get_possible_cpus();
127 		step = round_up(map_info->value_size, 8);
128 		for (i = 0; i < n; i++) {
129 			jsonw_start_object(d->jw);
130 			jsonw_int_field(d->jw, "cpu", i);
131 			jsonw_name(d->jw, "value");
132 			ret = btf_dumper_type(d, value_id, value + i * step);
133 			jsonw_end_object(d->jw);
134 			if (ret)
135 				break;
136 		}
137 		jsonw_end_array(d->jw);
138 	}
139 
140 err_end_obj:
141 	/* end of key-value pair */
142 	jsonw_end_object(d->jw);
143 
144 	return ret;
145 }
146 
147 static json_writer_t *get_btf_writer(void)
148 {
149 	json_writer_t *jw = jsonw_new(stdout);
150 
151 	if (!jw)
152 		return NULL;
153 	jsonw_pretty(jw, true);
154 
155 	return jw;
156 }
157 
158 static void print_entry_json(struct bpf_map_info *info, unsigned char *key,
159 			     unsigned char *value, struct btf *btf)
160 {
161 	jsonw_start_object(json_wtr);
162 
163 	if (!map_is_per_cpu(info->type)) {
164 		jsonw_name(json_wtr, "key");
165 		print_hex_data_json(key, info->key_size);
166 		jsonw_name(json_wtr, "value");
167 		print_hex_data_json(value, info->value_size);
168 		if (btf) {
169 			struct btf_dumper d = {
170 				.btf = btf,
171 				.jw = json_wtr,
172 				.is_plain_text = false,
173 			};
174 
175 			jsonw_name(json_wtr, "formatted");
176 			do_dump_btf(&d, info, key, value);
177 		}
178 	} else {
179 		unsigned int i, n, step;
180 
181 		n = get_possible_cpus();
182 		step = round_up(info->value_size, 8);
183 
184 		jsonw_name(json_wtr, "key");
185 		print_hex_data_json(key, info->key_size);
186 
187 		jsonw_name(json_wtr, "values");
188 		jsonw_start_array(json_wtr);
189 		for (i = 0; i < n; i++) {
190 			jsonw_start_object(json_wtr);
191 
192 			jsonw_int_field(json_wtr, "cpu", i);
193 
194 			jsonw_name(json_wtr, "value");
195 			print_hex_data_json(value + i * step,
196 					    info->value_size);
197 
198 			jsonw_end_object(json_wtr);
199 		}
200 		jsonw_end_array(json_wtr);
201 		if (btf) {
202 			struct btf_dumper d = {
203 				.btf = btf,
204 				.jw = json_wtr,
205 				.is_plain_text = false,
206 			};
207 
208 			jsonw_name(json_wtr, "formatted");
209 			do_dump_btf(&d, info, key, value);
210 		}
211 	}
212 
213 	jsonw_end_object(json_wtr);
214 }
215 
216 static void print_entry_error(struct bpf_map_info *info, unsigned char *key,
217 			      const char *error_msg)
218 {
219 	int msg_size = strlen(error_msg);
220 	bool single_line, break_names;
221 
222 	break_names = info->key_size > 16 || msg_size > 16;
223 	single_line = info->key_size + msg_size <= 24 && !break_names;
224 
225 	printf("key:%c", break_names ? '\n' : ' ');
226 	fprint_hex(stdout, key, info->key_size, " ");
227 
228 	printf(single_line ? "  " : "\n");
229 
230 	printf("value:%c%s", break_names ? '\n' : ' ', error_msg);
231 
232 	printf("\n");
233 }
234 
235 static void print_entry_plain(struct bpf_map_info *info, unsigned char *key,
236 			      unsigned char *value)
237 {
238 	if (!map_is_per_cpu(info->type)) {
239 		bool single_line, break_names;
240 
241 		break_names = info->key_size > 16 || info->value_size > 16;
242 		single_line = info->key_size + info->value_size <= 24 &&
243 			!break_names;
244 
245 		if (info->key_size) {
246 			printf("key:%c", break_names ? '\n' : ' ');
247 			fprint_hex(stdout, key, info->key_size, " ");
248 
249 			printf(single_line ? "  " : "\n");
250 		}
251 
252 		if (info->value_size) {
253 			printf("value:%c", break_names ? '\n' : ' ');
254 			fprint_hex(stdout, value, info->value_size, " ");
255 		}
256 
257 		printf("\n");
258 	} else {
259 		unsigned int i, n, step;
260 
261 		n = get_possible_cpus();
262 		step = round_up(info->value_size, 8);
263 
264 		if (info->key_size) {
265 			printf("key:\n");
266 			fprint_hex(stdout, key, info->key_size, " ");
267 			printf("\n");
268 		}
269 		if (info->value_size) {
270 			for (i = 0; i < n; i++) {
271 				printf("value (CPU %02d):%c",
272 				       i, info->value_size > 16 ? '\n' : ' ');
273 				fprint_hex(stdout, value + i * step,
274 					   info->value_size, " ");
275 				printf("\n");
276 			}
277 		}
278 	}
279 }
280 
281 static char **parse_bytes(char **argv, const char *name, unsigned char *val,
282 			  unsigned int n)
283 {
284 	unsigned int i = 0, base = 0;
285 	char *endptr;
286 
287 	if (is_prefix(*argv, "hex")) {
288 		base = 16;
289 		argv++;
290 	}
291 
292 	while (i < n && argv[i]) {
293 		val[i] = strtoul(argv[i], &endptr, base);
294 		if (*endptr) {
295 			p_err("error parsing byte: %s", argv[i]);
296 			return NULL;
297 		}
298 		i++;
299 	}
300 
301 	if (i != n) {
302 		p_err("%s expected %d bytes got %d", name, n, i);
303 		return NULL;
304 	}
305 
306 	return argv + i;
307 }
308 
309 /* on per cpu maps we must copy the provided value on all value instances */
310 static void fill_per_cpu_value(struct bpf_map_info *info, void *value)
311 {
312 	unsigned int i, n, step;
313 
314 	if (!map_is_per_cpu(info->type))
315 		return;
316 
317 	n = get_possible_cpus();
318 	step = round_up(info->value_size, 8);
319 	for (i = 1; i < n; i++)
320 		memcpy(value + i * step, value, info->value_size);
321 }
322 
323 static int parse_elem(char **argv, struct bpf_map_info *info,
324 		      void *key, void *value, __u32 key_size, __u32 value_size,
325 		      __u32 *flags, __u32 **value_fd)
326 {
327 	if (!*argv) {
328 		if (!key && !value)
329 			return 0;
330 		p_err("did not find %s", key ? "key" : "value");
331 		return -1;
332 	}
333 
334 	if (is_prefix(*argv, "key")) {
335 		if (!key) {
336 			if (key_size)
337 				p_err("duplicate key");
338 			else
339 				p_err("unnecessary key");
340 			return -1;
341 		}
342 
343 		argv = parse_bytes(argv + 1, "key", key, key_size);
344 		if (!argv)
345 			return -1;
346 
347 		return parse_elem(argv, info, NULL, value, key_size, value_size,
348 				  flags, value_fd);
349 	} else if (is_prefix(*argv, "value")) {
350 		int fd;
351 
352 		if (!value) {
353 			if (value_size)
354 				p_err("duplicate value");
355 			else
356 				p_err("unnecessary value");
357 			return -1;
358 		}
359 
360 		argv++;
361 
362 		if (map_is_map_of_maps(info->type)) {
363 			int argc = 2;
364 
365 			if (value_size != 4) {
366 				p_err("value smaller than 4B for map in map?");
367 				return -1;
368 			}
369 			if (!argv[0] || !argv[1]) {
370 				p_err("not enough value arguments for map in map");
371 				return -1;
372 			}
373 
374 			fd = map_parse_fd(&argc, &argv);
375 			if (fd < 0)
376 				return -1;
377 
378 			*value_fd = value;
379 			**value_fd = fd;
380 		} else if (map_is_map_of_progs(info->type)) {
381 			int argc = 2;
382 
383 			if (value_size != 4) {
384 				p_err("value smaller than 4B for map of progs?");
385 				return -1;
386 			}
387 			if (!argv[0] || !argv[1]) {
388 				p_err("not enough value arguments for map of progs");
389 				return -1;
390 			}
391 			if (is_prefix(*argv, "id"))
392 				p_info("Warning: updating program array via MAP_ID, make sure this map is kept open\n"
393 				       "         by some process or pinned otherwise update will be lost");
394 
395 			fd = prog_parse_fd(&argc, &argv);
396 			if (fd < 0)
397 				return -1;
398 
399 			*value_fd = value;
400 			**value_fd = fd;
401 		} else {
402 			argv = parse_bytes(argv, "value", value, value_size);
403 			if (!argv)
404 				return -1;
405 
406 			fill_per_cpu_value(info, value);
407 		}
408 
409 		return parse_elem(argv, info, key, NULL, key_size, value_size,
410 				  flags, NULL);
411 	} else if (is_prefix(*argv, "any") || is_prefix(*argv, "noexist") ||
412 		   is_prefix(*argv, "exist")) {
413 		if (!flags) {
414 			p_err("flags specified multiple times: %s", *argv);
415 			return -1;
416 		}
417 
418 		if (is_prefix(*argv, "any"))
419 			*flags = BPF_ANY;
420 		else if (is_prefix(*argv, "noexist"))
421 			*flags = BPF_NOEXIST;
422 		else if (is_prefix(*argv, "exist"))
423 			*flags = BPF_EXIST;
424 
425 		return parse_elem(argv + 1, info, key, value, key_size,
426 				  value_size, NULL, value_fd);
427 	}
428 
429 	p_err("expected key or value, got: %s", *argv);
430 	return -1;
431 }
432 
433 static void show_map_header_json(struct bpf_map_info *info, json_writer_t *wtr)
434 {
435 	jsonw_uint_field(wtr, "id", info->id);
436 	if (info->type < ARRAY_SIZE(map_type_name))
437 		jsonw_string_field(wtr, "type", map_type_name[info->type]);
438 	else
439 		jsonw_uint_field(wtr, "type", info->type);
440 
441 	if (*info->name)
442 		jsonw_string_field(wtr, "name", info->name);
443 
444 	jsonw_name(wtr, "flags");
445 	jsonw_printf(wtr, "%d", info->map_flags);
446 }
447 
448 static int show_map_close_json(int fd, struct bpf_map_info *info)
449 {
450 	char *memlock, *frozen_str;
451 	int frozen = 0;
452 
453 	memlock = get_fdinfo(fd, "memlock");
454 	frozen_str = get_fdinfo(fd, "frozen");
455 
456 	jsonw_start_object(json_wtr);
457 
458 	show_map_header_json(info, json_wtr);
459 
460 	print_dev_json(info->ifindex, info->netns_dev, info->netns_ino);
461 
462 	jsonw_uint_field(json_wtr, "bytes_key", info->key_size);
463 	jsonw_uint_field(json_wtr, "bytes_value", info->value_size);
464 	jsonw_uint_field(json_wtr, "max_entries", info->max_entries);
465 
466 	if (memlock)
467 		jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
468 	free(memlock);
469 
470 	if (info->type == BPF_MAP_TYPE_PROG_ARRAY) {
471 		char *owner_prog_type = get_fdinfo(fd, "owner_prog_type");
472 		char *owner_jited = get_fdinfo(fd, "owner_jited");
473 
474 		if (owner_prog_type) {
475 			unsigned int prog_type = atoi(owner_prog_type);
476 
477 			if (prog_type < prog_type_name_size)
478 				jsonw_string_field(json_wtr, "owner_prog_type",
479 						   prog_type_name[prog_type]);
480 			else
481 				jsonw_uint_field(json_wtr, "owner_prog_type",
482 						 prog_type);
483 		}
484 		if (owner_jited)
485 			jsonw_bool_field(json_wtr, "owner_jited",
486 					 !!atoi(owner_jited));
487 
488 		free(owner_prog_type);
489 		free(owner_jited);
490 	}
491 	close(fd);
492 
493 	if (frozen_str) {
494 		frozen = atoi(frozen_str);
495 		free(frozen_str);
496 	}
497 	jsonw_int_field(json_wtr, "frozen", frozen);
498 
499 	if (info->btf_id)
500 		jsonw_int_field(json_wtr, "btf_id", info->btf_id);
501 
502 	if (!hash_empty(map_table.table)) {
503 		struct pinned_obj *obj;
504 
505 		jsonw_name(json_wtr, "pinned");
506 		jsonw_start_array(json_wtr);
507 		hash_for_each_possible(map_table.table, obj, hash, info->id) {
508 			if (obj->id == info->id)
509 				jsonw_string(json_wtr, obj->path);
510 		}
511 		jsonw_end_array(json_wtr);
512 	}
513 
514 	emit_obj_refs_json(&refs_table, info->id, json_wtr);
515 
516 	jsonw_end_object(json_wtr);
517 
518 	return 0;
519 }
520 
521 static void show_map_header_plain(struct bpf_map_info *info)
522 {
523 	printf("%u: ", info->id);
524 	if (info->type < ARRAY_SIZE(map_type_name))
525 		printf("%s  ", map_type_name[info->type]);
526 	else
527 		printf("type %u  ", info->type);
528 
529 	if (*info->name)
530 		printf("name %s  ", info->name);
531 
532 	printf("flags 0x%x", info->map_flags);
533 	print_dev_plain(info->ifindex, info->netns_dev, info->netns_ino);
534 	printf("\n");
535 }
536 
537 static int show_map_close_plain(int fd, struct bpf_map_info *info)
538 {
539 	char *memlock, *frozen_str;
540 	int frozen = 0;
541 
542 	memlock = get_fdinfo(fd, "memlock");
543 	frozen_str = get_fdinfo(fd, "frozen");
544 
545 	show_map_header_plain(info);
546 	printf("\tkey %uB  value %uB  max_entries %u",
547 	       info->key_size, info->value_size, info->max_entries);
548 
549 	if (memlock)
550 		printf("  memlock %sB", memlock);
551 	free(memlock);
552 
553 	if (info->type == BPF_MAP_TYPE_PROG_ARRAY) {
554 		char *owner_prog_type = get_fdinfo(fd, "owner_prog_type");
555 		char *owner_jited = get_fdinfo(fd, "owner_jited");
556 
557 		if (owner_prog_type || owner_jited)
558 			printf("\n\t");
559 		if (owner_prog_type) {
560 			unsigned int prog_type = atoi(owner_prog_type);
561 
562 			if (prog_type < prog_type_name_size)
563 				printf("owner_prog_type %s  ",
564 				       prog_type_name[prog_type]);
565 			else
566 				printf("owner_prog_type %d  ", prog_type);
567 		}
568 		if (owner_jited)
569 			printf("owner%s jited",
570 			       atoi(owner_jited) ? "" : " not");
571 
572 		free(owner_prog_type);
573 		free(owner_jited);
574 	}
575 	close(fd);
576 
577 	if (!hash_empty(map_table.table)) {
578 		struct pinned_obj *obj;
579 
580 		hash_for_each_possible(map_table.table, obj, hash, info->id) {
581 			if (obj->id == info->id)
582 				printf("\n\tpinned %s", obj->path);
583 		}
584 	}
585 	printf("\n");
586 
587 	if (frozen_str) {
588 		frozen = atoi(frozen_str);
589 		free(frozen_str);
590 	}
591 
592 	if (!info->btf_id && !frozen)
593 		return 0;
594 
595 	printf("\t");
596 
597 	if (info->btf_id)
598 		printf("btf_id %d", info->btf_id);
599 
600 	if (frozen)
601 		printf("%sfrozen", info->btf_id ? "  " : "");
602 
603 	emit_obj_refs_plain(&refs_table, info->id, "\n\tpids ");
604 
605 	printf("\n");
606 	return 0;
607 }
608 
609 static int do_show_subset(int argc, char **argv)
610 {
611 	struct bpf_map_info info = {};
612 	__u32 len = sizeof(info);
613 	int *fds = NULL;
614 	int nb_fds, i;
615 	int err = -1;
616 
617 	fds = malloc(sizeof(int));
618 	if (!fds) {
619 		p_err("mem alloc failed");
620 		return -1;
621 	}
622 	nb_fds = map_parse_fds(&argc, &argv, &fds);
623 	if (nb_fds < 1)
624 		goto exit_free;
625 
626 	if (json_output && nb_fds > 1)
627 		jsonw_start_array(json_wtr);	/* root array */
628 	for (i = 0; i < nb_fds; i++) {
629 		err = bpf_obj_get_info_by_fd(fds[i], &info, &len);
630 		if (err) {
631 			p_err("can't get map info: %s",
632 			      strerror(errno));
633 			for (; i < nb_fds; i++)
634 				close(fds[i]);
635 			break;
636 		}
637 
638 		if (json_output)
639 			show_map_close_json(fds[i], &info);
640 		else
641 			show_map_close_plain(fds[i], &info);
642 
643 		close(fds[i]);
644 	}
645 	if (json_output && nb_fds > 1)
646 		jsonw_end_array(json_wtr);	/* root array */
647 
648 exit_free:
649 	free(fds);
650 	return err;
651 }
652 
653 static int do_show(int argc, char **argv)
654 {
655 	struct bpf_map_info info = {};
656 	__u32 len = sizeof(info);
657 	__u32 id = 0;
658 	int err;
659 	int fd;
660 
661 	if (show_pinned)
662 		build_pinned_obj_table(&map_table, BPF_OBJ_MAP);
663 	build_obj_refs_table(&refs_table, BPF_OBJ_MAP);
664 
665 	if (argc == 2)
666 		return do_show_subset(argc, argv);
667 
668 	if (argc)
669 		return BAD_ARG();
670 
671 	if (json_output)
672 		jsonw_start_array(json_wtr);
673 	while (true) {
674 		err = bpf_map_get_next_id(id, &id);
675 		if (err) {
676 			if (errno == ENOENT)
677 				break;
678 			p_err("can't get next map: %s%s", strerror(errno),
679 			      errno == EINVAL ? " -- kernel too old?" : "");
680 			break;
681 		}
682 
683 		fd = bpf_map_get_fd_by_id(id);
684 		if (fd < 0) {
685 			if (errno == ENOENT)
686 				continue;
687 			p_err("can't get map by id (%u): %s",
688 			      id, strerror(errno));
689 			break;
690 		}
691 
692 		err = bpf_obj_get_info_by_fd(fd, &info, &len);
693 		if (err) {
694 			p_err("can't get map info: %s", strerror(errno));
695 			close(fd);
696 			break;
697 		}
698 
699 		if (json_output)
700 			show_map_close_json(fd, &info);
701 		else
702 			show_map_close_plain(fd, &info);
703 	}
704 	if (json_output)
705 		jsonw_end_array(json_wtr);
706 
707 	delete_obj_refs_table(&refs_table);
708 
709 	return errno == ENOENT ? 0 : -1;
710 }
711 
712 static int dump_map_elem(int fd, void *key, void *value,
713 			 struct bpf_map_info *map_info, struct btf *btf,
714 			 json_writer_t *btf_wtr)
715 {
716 	int num_elems = 0;
717 	int lookup_errno;
718 
719 	if (!bpf_map_lookup_elem(fd, key, value)) {
720 		if (json_output) {
721 			print_entry_json(map_info, key, value, btf);
722 		} else {
723 			if (btf) {
724 				struct btf_dumper d = {
725 					.btf = btf,
726 					.jw = btf_wtr,
727 					.is_plain_text = true,
728 				};
729 
730 				do_dump_btf(&d, map_info, key, value);
731 			} else {
732 				print_entry_plain(map_info, key, value);
733 			}
734 			num_elems++;
735 		}
736 		return num_elems;
737 	}
738 
739 	/* lookup error handling */
740 	lookup_errno = errno;
741 
742 	if (map_is_map_of_maps(map_info->type) ||
743 	    map_is_map_of_progs(map_info->type))
744 		return 0;
745 
746 	if (json_output) {
747 		jsonw_start_object(json_wtr);
748 		jsonw_name(json_wtr, "key");
749 		print_hex_data_json(key, map_info->key_size);
750 		jsonw_name(json_wtr, "value");
751 		jsonw_start_object(json_wtr);
752 		jsonw_string_field(json_wtr, "error", strerror(lookup_errno));
753 		jsonw_end_object(json_wtr);
754 		jsonw_end_object(json_wtr);
755 	} else {
756 		const char *msg = NULL;
757 
758 		if (lookup_errno == ENOENT)
759 			msg = "<no entry>";
760 		else if (lookup_errno == ENOSPC &&
761 			 map_info->type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY)
762 			msg = "<cannot read>";
763 
764 		print_entry_error(map_info, key,
765 				  msg ? : strerror(lookup_errno));
766 	}
767 
768 	return 0;
769 }
770 
771 static int maps_have_btf(int *fds, int nb_fds)
772 {
773 	struct bpf_map_info info = {};
774 	__u32 len = sizeof(info);
775 	int err, i;
776 
777 	for (i = 0; i < nb_fds; i++) {
778 		err = bpf_obj_get_info_by_fd(fds[i], &info, &len);
779 		if (err) {
780 			p_err("can't get map info: %s", strerror(errno));
781 			return -1;
782 		}
783 
784 		if (!info.btf_id)
785 			return 0;
786 	}
787 
788 	return 1;
789 }
790 
791 static struct btf *btf_vmlinux;
792 
793 static struct btf *get_map_kv_btf(const struct bpf_map_info *info)
794 {
795 	struct btf *btf = NULL;
796 
797 	if (info->btf_vmlinux_value_type_id) {
798 		if (!btf_vmlinux) {
799 			btf_vmlinux = libbpf_find_kernel_btf();
800 			if (IS_ERR(btf_vmlinux))
801 				p_err("failed to get kernel btf");
802 		}
803 		return btf_vmlinux;
804 	} else if (info->btf_value_type_id) {
805 		int err;
806 
807 		err = btf__get_from_id(info->btf_id, &btf);
808 		if (err || !btf) {
809 			p_err("failed to get btf");
810 			btf = err ? ERR_PTR(err) : ERR_PTR(-ESRCH);
811 		}
812 	}
813 
814 	return btf;
815 }
816 
817 static void free_map_kv_btf(struct btf *btf)
818 {
819 	if (!IS_ERR(btf) && btf != btf_vmlinux)
820 		btf__free(btf);
821 }
822 
823 static void free_btf_vmlinux(void)
824 {
825 	if (!IS_ERR(btf_vmlinux))
826 		btf__free(btf_vmlinux);
827 }
828 
829 static int
830 map_dump(int fd, struct bpf_map_info *info, json_writer_t *wtr,
831 	 bool show_header)
832 {
833 	void *key, *value, *prev_key;
834 	unsigned int num_elems = 0;
835 	struct btf *btf = NULL;
836 	int err;
837 
838 	key = malloc(info->key_size);
839 	value = alloc_value(info);
840 	if (!key || !value) {
841 		p_err("mem alloc failed");
842 		err = -1;
843 		goto exit_free;
844 	}
845 
846 	prev_key = NULL;
847 
848 	if (wtr) {
849 		btf = get_map_kv_btf(info);
850 		if (IS_ERR(btf)) {
851 			err = PTR_ERR(btf);
852 			goto exit_free;
853 		}
854 
855 		if (show_header) {
856 			jsonw_start_object(wtr);	/* map object */
857 			show_map_header_json(info, wtr);
858 			jsonw_name(wtr, "elements");
859 		}
860 		jsonw_start_array(wtr);		/* elements */
861 	} else if (show_header) {
862 		show_map_header_plain(info);
863 	}
864 
865 	if (info->type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY &&
866 	    info->value_size != 8)
867 		p_info("Warning: cannot read values from %s map with value_size != 8",
868 		       map_type_name[info->type]);
869 	while (true) {
870 		err = bpf_map_get_next_key(fd, prev_key, key);
871 		if (err) {
872 			if (errno == ENOENT)
873 				err = 0;
874 			break;
875 		}
876 		num_elems += dump_map_elem(fd, key, value, info, btf, wtr);
877 		prev_key = key;
878 	}
879 
880 	if (wtr) {
881 		jsonw_end_array(wtr);	/* elements */
882 		if (show_header)
883 			jsonw_end_object(wtr);	/* map object */
884 	} else {
885 		printf("Found %u element%s\n", num_elems,
886 		       num_elems != 1 ? "s" : "");
887 	}
888 
889 exit_free:
890 	free(key);
891 	free(value);
892 	close(fd);
893 	free_map_kv_btf(btf);
894 
895 	return err;
896 }
897 
898 static int do_dump(int argc, char **argv)
899 {
900 	json_writer_t *wtr = NULL, *btf_wtr = NULL;
901 	struct bpf_map_info info = {};
902 	int nb_fds, i = 0;
903 	__u32 len = sizeof(info);
904 	int *fds = NULL;
905 	int err = -1;
906 
907 	if (argc != 2)
908 		usage();
909 
910 	fds = malloc(sizeof(int));
911 	if (!fds) {
912 		p_err("mem alloc failed");
913 		return -1;
914 	}
915 	nb_fds = map_parse_fds(&argc, &argv, &fds);
916 	if (nb_fds < 1)
917 		goto exit_free;
918 
919 	if (json_output) {
920 		wtr = json_wtr;
921 	} else {
922 		int do_plain_btf;
923 
924 		do_plain_btf = maps_have_btf(fds, nb_fds);
925 		if (do_plain_btf < 0)
926 			goto exit_close;
927 
928 		if (do_plain_btf) {
929 			btf_wtr = get_btf_writer();
930 			wtr = btf_wtr;
931 			if (!btf_wtr)
932 				p_info("failed to create json writer for btf. falling back to plain output");
933 		}
934 	}
935 
936 	if (wtr && nb_fds > 1)
937 		jsonw_start_array(wtr);	/* root array */
938 	for (i = 0; i < nb_fds; i++) {
939 		if (bpf_obj_get_info_by_fd(fds[i], &info, &len)) {
940 			p_err("can't get map info: %s", strerror(errno));
941 			break;
942 		}
943 		err = map_dump(fds[i], &info, wtr, nb_fds > 1);
944 		if (!wtr && i != nb_fds - 1)
945 			printf("\n");
946 
947 		if (err)
948 			break;
949 		close(fds[i]);
950 	}
951 	if (wtr && nb_fds > 1)
952 		jsonw_end_array(wtr);	/* root array */
953 
954 	if (btf_wtr)
955 		jsonw_destroy(&btf_wtr);
956 exit_close:
957 	for (; i < nb_fds; i++)
958 		close(fds[i]);
959 exit_free:
960 	free(fds);
961 	free_btf_vmlinux();
962 	return err;
963 }
964 
965 static int alloc_key_value(struct bpf_map_info *info, void **key, void **value)
966 {
967 	*key = NULL;
968 	*value = NULL;
969 
970 	if (info->key_size) {
971 		*key = malloc(info->key_size);
972 		if (!*key) {
973 			p_err("key mem alloc failed");
974 			return -1;
975 		}
976 	}
977 
978 	if (info->value_size) {
979 		*value = alloc_value(info);
980 		if (!*value) {
981 			p_err("value mem alloc failed");
982 			free(*key);
983 			*key = NULL;
984 			return -1;
985 		}
986 	}
987 
988 	return 0;
989 }
990 
991 static int do_update(int argc, char **argv)
992 {
993 	struct bpf_map_info info = {};
994 	__u32 len = sizeof(info);
995 	__u32 *value_fd = NULL;
996 	__u32 flags = BPF_ANY;
997 	void *key, *value;
998 	int fd, err;
999 
1000 	if (argc < 2)
1001 		usage();
1002 
1003 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
1004 	if (fd < 0)
1005 		return -1;
1006 
1007 	err = alloc_key_value(&info, &key, &value);
1008 	if (err)
1009 		goto exit_free;
1010 
1011 	err = parse_elem(argv, &info, key, value, info.key_size,
1012 			 info.value_size, &flags, &value_fd);
1013 	if (err)
1014 		goto exit_free;
1015 
1016 	err = bpf_map_update_elem(fd, key, value, flags);
1017 	if (err) {
1018 		p_err("update failed: %s", strerror(errno));
1019 		goto exit_free;
1020 	}
1021 
1022 exit_free:
1023 	if (value_fd)
1024 		close(*value_fd);
1025 	free(key);
1026 	free(value);
1027 	close(fd);
1028 
1029 	if (!err && json_output)
1030 		jsonw_null(json_wtr);
1031 	return err;
1032 }
1033 
1034 static void print_key_value(struct bpf_map_info *info, void *key,
1035 			    void *value)
1036 {
1037 	json_writer_t *btf_wtr;
1038 	struct btf *btf = NULL;
1039 	int err;
1040 
1041 	err = btf__get_from_id(info->btf_id, &btf);
1042 	if (err) {
1043 		p_err("failed to get btf");
1044 		return;
1045 	}
1046 
1047 	if (json_output) {
1048 		print_entry_json(info, key, value, btf);
1049 	} else if (btf) {
1050 		/* if here json_wtr wouldn't have been initialised,
1051 		 * so let's create separate writer for btf
1052 		 */
1053 		btf_wtr = get_btf_writer();
1054 		if (!btf_wtr) {
1055 			p_info("failed to create json writer for btf. falling back to plain output");
1056 			btf__free(btf);
1057 			btf = NULL;
1058 			print_entry_plain(info, key, value);
1059 		} else {
1060 			struct btf_dumper d = {
1061 				.btf = btf,
1062 				.jw = btf_wtr,
1063 				.is_plain_text = true,
1064 			};
1065 
1066 			do_dump_btf(&d, info, key, value);
1067 			jsonw_destroy(&btf_wtr);
1068 		}
1069 	} else {
1070 		print_entry_plain(info, key, value);
1071 	}
1072 	btf__free(btf);
1073 }
1074 
1075 static int do_lookup(int argc, char **argv)
1076 {
1077 	struct bpf_map_info info = {};
1078 	__u32 len = sizeof(info);
1079 	void *key, *value;
1080 	int err;
1081 	int fd;
1082 
1083 	if (argc < 2)
1084 		usage();
1085 
1086 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
1087 	if (fd < 0)
1088 		return -1;
1089 
1090 	err = alloc_key_value(&info, &key, &value);
1091 	if (err)
1092 		goto exit_free;
1093 
1094 	err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
1095 	if (err)
1096 		goto exit_free;
1097 
1098 	err = bpf_map_lookup_elem(fd, key, value);
1099 	if (err) {
1100 		if (errno == ENOENT) {
1101 			if (json_output) {
1102 				jsonw_null(json_wtr);
1103 			} else {
1104 				printf("key:\n");
1105 				fprint_hex(stdout, key, info.key_size, " ");
1106 				printf("\n\nNot found\n");
1107 			}
1108 		} else {
1109 			p_err("lookup failed: %s", strerror(errno));
1110 		}
1111 
1112 		goto exit_free;
1113 	}
1114 
1115 	/* here means bpf_map_lookup_elem() succeeded */
1116 	print_key_value(&info, key, value);
1117 
1118 exit_free:
1119 	free(key);
1120 	free(value);
1121 	close(fd);
1122 
1123 	return err;
1124 }
1125 
1126 static int do_getnext(int argc, char **argv)
1127 {
1128 	struct bpf_map_info info = {};
1129 	__u32 len = sizeof(info);
1130 	void *key, *nextkey;
1131 	int err;
1132 	int fd;
1133 
1134 	if (argc < 2)
1135 		usage();
1136 
1137 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
1138 	if (fd < 0)
1139 		return -1;
1140 
1141 	key = malloc(info.key_size);
1142 	nextkey = malloc(info.key_size);
1143 	if (!key || !nextkey) {
1144 		p_err("mem alloc failed");
1145 		err = -1;
1146 		goto exit_free;
1147 	}
1148 
1149 	if (argc) {
1150 		err = parse_elem(argv, &info, key, NULL, info.key_size, 0,
1151 				 NULL, NULL);
1152 		if (err)
1153 			goto exit_free;
1154 	} else {
1155 		free(key);
1156 		key = NULL;
1157 	}
1158 
1159 	err = bpf_map_get_next_key(fd, key, nextkey);
1160 	if (err) {
1161 		p_err("can't get next key: %s", strerror(errno));
1162 		goto exit_free;
1163 	}
1164 
1165 	if (json_output) {
1166 		jsonw_start_object(json_wtr);
1167 		if (key) {
1168 			jsonw_name(json_wtr, "key");
1169 			print_hex_data_json(key, info.key_size);
1170 		} else {
1171 			jsonw_null_field(json_wtr, "key");
1172 		}
1173 		jsonw_name(json_wtr, "next_key");
1174 		print_hex_data_json(nextkey, info.key_size);
1175 		jsonw_end_object(json_wtr);
1176 	} else {
1177 		if (key) {
1178 			printf("key:\n");
1179 			fprint_hex(stdout, key, info.key_size, " ");
1180 			printf("\n");
1181 		} else {
1182 			printf("key: None\n");
1183 		}
1184 		printf("next key:\n");
1185 		fprint_hex(stdout, nextkey, info.key_size, " ");
1186 		printf("\n");
1187 	}
1188 
1189 exit_free:
1190 	free(nextkey);
1191 	free(key);
1192 	close(fd);
1193 
1194 	return err;
1195 }
1196 
1197 static int do_delete(int argc, char **argv)
1198 {
1199 	struct bpf_map_info info = {};
1200 	__u32 len = sizeof(info);
1201 	void *key;
1202 	int err;
1203 	int fd;
1204 
1205 	if (argc < 2)
1206 		usage();
1207 
1208 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
1209 	if (fd < 0)
1210 		return -1;
1211 
1212 	key = malloc(info.key_size);
1213 	if (!key) {
1214 		p_err("mem alloc failed");
1215 		err = -1;
1216 		goto exit_free;
1217 	}
1218 
1219 	err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
1220 	if (err)
1221 		goto exit_free;
1222 
1223 	err = bpf_map_delete_elem(fd, key);
1224 	if (err)
1225 		p_err("delete failed: %s", strerror(errno));
1226 
1227 exit_free:
1228 	free(key);
1229 	close(fd);
1230 
1231 	if (!err && json_output)
1232 		jsonw_null(json_wtr);
1233 	return err;
1234 }
1235 
1236 static int do_pin(int argc, char **argv)
1237 {
1238 	int err;
1239 
1240 	err = do_pin_any(argc, argv, map_parse_fd);
1241 	if (!err && json_output)
1242 		jsonw_null(json_wtr);
1243 	return err;
1244 }
1245 
1246 static int do_create(int argc, char **argv)
1247 {
1248 	struct bpf_create_map_attr attr = { NULL, };
1249 	const char *pinfile;
1250 	int err, fd;
1251 
1252 	if (!REQ_ARGS(7))
1253 		return -1;
1254 	pinfile = GET_ARG();
1255 
1256 	while (argc) {
1257 		if (!REQ_ARGS(2))
1258 			return -1;
1259 
1260 		if (is_prefix(*argv, "type")) {
1261 			NEXT_ARG();
1262 
1263 			if (attr.map_type) {
1264 				p_err("map type already specified");
1265 				return -1;
1266 			}
1267 
1268 			attr.map_type = map_type_from_str(*argv);
1269 			if ((int)attr.map_type < 0) {
1270 				p_err("unrecognized map type: %s", *argv);
1271 				return -1;
1272 			}
1273 			NEXT_ARG();
1274 		} else if (is_prefix(*argv, "name")) {
1275 			NEXT_ARG();
1276 			attr.name = GET_ARG();
1277 		} else if (is_prefix(*argv, "key")) {
1278 			if (parse_u32_arg(&argc, &argv, &attr.key_size,
1279 					  "key size"))
1280 				return -1;
1281 		} else if (is_prefix(*argv, "value")) {
1282 			if (parse_u32_arg(&argc, &argv, &attr.value_size,
1283 					  "value size"))
1284 				return -1;
1285 		} else if (is_prefix(*argv, "entries")) {
1286 			if (parse_u32_arg(&argc, &argv, &attr.max_entries,
1287 					  "max entries"))
1288 				return -1;
1289 		} else if (is_prefix(*argv, "flags")) {
1290 			if (parse_u32_arg(&argc, &argv, &attr.map_flags,
1291 					  "flags"))
1292 				return -1;
1293 		} else if (is_prefix(*argv, "dev")) {
1294 			NEXT_ARG();
1295 
1296 			if (attr.map_ifindex) {
1297 				p_err("offload device already specified");
1298 				return -1;
1299 			}
1300 
1301 			attr.map_ifindex = if_nametoindex(*argv);
1302 			if (!attr.map_ifindex) {
1303 				p_err("unrecognized netdevice '%s': %s",
1304 				      *argv, strerror(errno));
1305 				return -1;
1306 			}
1307 			NEXT_ARG();
1308 		} else {
1309 			p_err("unknown arg %s", *argv);
1310 			return -1;
1311 		}
1312 	}
1313 
1314 	if (!attr.name) {
1315 		p_err("map name not specified");
1316 		return -1;
1317 	}
1318 
1319 	set_max_rlimit();
1320 
1321 	fd = bpf_create_map_xattr(&attr);
1322 	if (fd < 0) {
1323 		p_err("map create failed: %s", strerror(errno));
1324 		return -1;
1325 	}
1326 
1327 	err = do_pin_fd(fd, pinfile);
1328 	close(fd);
1329 	if (err)
1330 		return err;
1331 
1332 	if (json_output)
1333 		jsonw_null(json_wtr);
1334 	return 0;
1335 }
1336 
1337 static int do_pop_dequeue(int argc, char **argv)
1338 {
1339 	struct bpf_map_info info = {};
1340 	__u32 len = sizeof(info);
1341 	void *key, *value;
1342 	int err;
1343 	int fd;
1344 
1345 	if (argc < 2)
1346 		usage();
1347 
1348 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
1349 	if (fd < 0)
1350 		return -1;
1351 
1352 	err = alloc_key_value(&info, &key, &value);
1353 	if (err)
1354 		goto exit_free;
1355 
1356 	err = bpf_map_lookup_and_delete_elem(fd, key, value);
1357 	if (err) {
1358 		if (errno == ENOENT) {
1359 			if (json_output)
1360 				jsonw_null(json_wtr);
1361 			else
1362 				printf("Error: empty map\n");
1363 		} else {
1364 			p_err("pop failed: %s", strerror(errno));
1365 		}
1366 
1367 		goto exit_free;
1368 	}
1369 
1370 	print_key_value(&info, key, value);
1371 
1372 exit_free:
1373 	free(key);
1374 	free(value);
1375 	close(fd);
1376 
1377 	return err;
1378 }
1379 
1380 static int do_freeze(int argc, char **argv)
1381 {
1382 	int err, fd;
1383 
1384 	if (!REQ_ARGS(2))
1385 		return -1;
1386 
1387 	fd = map_parse_fd(&argc, &argv);
1388 	if (fd < 0)
1389 		return -1;
1390 
1391 	if (argc) {
1392 		close(fd);
1393 		return BAD_ARG();
1394 	}
1395 
1396 	err = bpf_map_freeze(fd);
1397 	close(fd);
1398 	if (err) {
1399 		p_err("failed to freeze map: %s", strerror(errno));
1400 		return err;
1401 	}
1402 
1403 	if (json_output)
1404 		jsonw_null(json_wtr);
1405 
1406 	return 0;
1407 }
1408 
1409 static int do_help(int argc, char **argv)
1410 {
1411 	if (json_output) {
1412 		jsonw_null(json_wtr);
1413 		return 0;
1414 	}
1415 
1416 	fprintf(stderr,
1417 		"Usage: %1$s %2$s { show | list }   [MAP]\n"
1418 		"       %1$s %2$s create     FILE type TYPE key KEY_SIZE value VALUE_SIZE \\\n"
1419 		"                                  entries MAX_ENTRIES name NAME [flags FLAGS] \\\n"
1420 		"                                  [dev NAME]\n"
1421 		"       %1$s %2$s dump       MAP\n"
1422 		"       %1$s %2$s update     MAP [key DATA] [value VALUE] [UPDATE_FLAGS]\n"
1423 		"       %1$s %2$s lookup     MAP [key DATA]\n"
1424 		"       %1$s %2$s getnext    MAP [key DATA]\n"
1425 		"       %1$s %2$s delete     MAP  key DATA\n"
1426 		"       %1$s %2$s pin        MAP  FILE\n"
1427 		"       %1$s %2$s event_pipe MAP [cpu N index M]\n"
1428 		"       %1$s %2$s peek       MAP\n"
1429 		"       %1$s %2$s push       MAP value VALUE\n"
1430 		"       %1$s %2$s pop        MAP\n"
1431 		"       %1$s %2$s enqueue    MAP value VALUE\n"
1432 		"       %1$s %2$s dequeue    MAP\n"
1433 		"       %1$s %2$s freeze     MAP\n"
1434 		"       %1$s %2$s help\n"
1435 		"\n"
1436 		"       " HELP_SPEC_MAP "\n"
1437 		"       DATA := { [hex] BYTES }\n"
1438 		"       " HELP_SPEC_PROGRAM "\n"
1439 		"       VALUE := { DATA | MAP | PROG }\n"
1440 		"       UPDATE_FLAGS := { any | exist | noexist }\n"
1441 		"       TYPE := { hash | array | prog_array | perf_event_array | percpu_hash |\n"
1442 		"                 percpu_array | stack_trace | cgroup_array | lru_hash |\n"
1443 		"                 lru_percpu_hash | lpm_trie | array_of_maps | hash_of_maps |\n"
1444 		"                 devmap | devmap_hash | sockmap | cpumap | xskmap | sockhash |\n"
1445 		"                 cgroup_storage | reuseport_sockarray | percpu_cgroup_storage |\n"
1446 		"                 queue | stack | sk_storage | struct_ops | ringbuf | inode_storage }\n"
1447 		"       " HELP_SPEC_OPTIONS "\n"
1448 		"",
1449 		bin_name, argv[-2]);
1450 
1451 	return 0;
1452 }
1453 
1454 static const struct cmd cmds[] = {
1455 	{ "show",	do_show },
1456 	{ "list",	do_show },
1457 	{ "help",	do_help },
1458 	{ "dump",	do_dump },
1459 	{ "update",	do_update },
1460 	{ "lookup",	do_lookup },
1461 	{ "getnext",	do_getnext },
1462 	{ "delete",	do_delete },
1463 	{ "pin",	do_pin },
1464 	{ "event_pipe",	do_event_pipe },
1465 	{ "create",	do_create },
1466 	{ "peek",	do_lookup },
1467 	{ "push",	do_update },
1468 	{ "enqueue",	do_update },
1469 	{ "pop",	do_pop_dequeue },
1470 	{ "dequeue",	do_pop_dequeue },
1471 	{ "freeze",	do_freeze },
1472 	{ 0 }
1473 };
1474 
1475 int do_map(int argc, char **argv)
1476 {
1477 	return cmd_select(cmds, argc, argv, do_help);
1478 }
1479