xref: /openbmc/linux/tools/bpf/bpftool/map.c (revision cfdfc14e)
1 /*
2  * Copyright (C) 2017-2018 Netronome Systems, Inc.
3  *
4  * This software is dual licensed under the GNU General License Version 2,
5  * June 1991 as shown in the file COPYING in the top-level directory of this
6  * source tree or the BSD 2-Clause License provided below.  You have the
7  * option to license this software under the complete terms of either license.
8  *
9  * The BSD 2-Clause License:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      1. Redistributions of source code must retain the above
16  *         copyright notice, this list of conditions and the following
17  *         disclaimer.
18  *
19  *      2. Redistributions in binary form must reproduce the above
20  *         copyright notice, this list of conditions and the following
21  *         disclaimer in the documentation and/or other materials
22  *         provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 /* Author: Jakub Kicinski <kubakici@wp.pl> */
35 
36 #include <assert.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <stdbool.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <unistd.h>
44 #include <sys/types.h>
45 #include <sys/stat.h>
46 
47 #include <bpf.h>
48 
49 #include "main.h"
50 
51 static const char * const map_type_name[] = {
52 	[BPF_MAP_TYPE_UNSPEC]		= "unspec",
53 	[BPF_MAP_TYPE_HASH]		= "hash",
54 	[BPF_MAP_TYPE_ARRAY]		= "array",
55 	[BPF_MAP_TYPE_PROG_ARRAY]	= "prog_array",
56 	[BPF_MAP_TYPE_PERF_EVENT_ARRAY]	= "perf_event_array",
57 	[BPF_MAP_TYPE_PERCPU_HASH]	= "percpu_hash",
58 	[BPF_MAP_TYPE_PERCPU_ARRAY]	= "percpu_array",
59 	[BPF_MAP_TYPE_STACK_TRACE]	= "stack_trace",
60 	[BPF_MAP_TYPE_CGROUP_ARRAY]	= "cgroup_array",
61 	[BPF_MAP_TYPE_LRU_HASH]		= "lru_hash",
62 	[BPF_MAP_TYPE_LRU_PERCPU_HASH]	= "lru_percpu_hash",
63 	[BPF_MAP_TYPE_LPM_TRIE]		= "lpm_trie",
64 	[BPF_MAP_TYPE_ARRAY_OF_MAPS]	= "array_of_maps",
65 	[BPF_MAP_TYPE_HASH_OF_MAPS]	= "hash_of_maps",
66 	[BPF_MAP_TYPE_DEVMAP]		= "devmap",
67 	[BPF_MAP_TYPE_SOCKMAP]		= "sockmap",
68 	[BPF_MAP_TYPE_CPUMAP]		= "cpumap",
69 	[BPF_MAP_TYPE_SOCKHASH]		= "sockhash",
70 };
71 
72 static bool map_is_per_cpu(__u32 type)
73 {
74 	return type == BPF_MAP_TYPE_PERCPU_HASH ||
75 	       type == BPF_MAP_TYPE_PERCPU_ARRAY ||
76 	       type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
77 }
78 
79 static bool map_is_map_of_maps(__u32 type)
80 {
81 	return type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
82 	       type == BPF_MAP_TYPE_HASH_OF_MAPS;
83 }
84 
85 static bool map_is_map_of_progs(__u32 type)
86 {
87 	return type == BPF_MAP_TYPE_PROG_ARRAY;
88 }
89 
90 static void *alloc_value(struct bpf_map_info *info)
91 {
92 	if (map_is_per_cpu(info->type))
93 		return malloc(info->value_size * get_possible_cpus());
94 	else
95 		return malloc(info->value_size);
96 }
97 
98 static int map_parse_fd(int *argc, char ***argv)
99 {
100 	int fd;
101 
102 	if (is_prefix(**argv, "id")) {
103 		unsigned int id;
104 		char *endptr;
105 
106 		NEXT_ARGP();
107 
108 		id = strtoul(**argv, &endptr, 0);
109 		if (*endptr) {
110 			p_err("can't parse %s as ID", **argv);
111 			return -1;
112 		}
113 		NEXT_ARGP();
114 
115 		fd = bpf_map_get_fd_by_id(id);
116 		if (fd < 0)
117 			p_err("get map by id (%u): %s", id, strerror(errno));
118 		return fd;
119 	} else if (is_prefix(**argv, "pinned")) {
120 		char *path;
121 
122 		NEXT_ARGP();
123 
124 		path = **argv;
125 		NEXT_ARGP();
126 
127 		return open_obj_pinned_any(path, BPF_OBJ_MAP);
128 	}
129 
130 	p_err("expected 'id' or 'pinned', got: '%s'?", **argv);
131 	return -1;
132 }
133 
134 int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
135 {
136 	int err;
137 	int fd;
138 
139 	fd = map_parse_fd(argc, argv);
140 	if (fd < 0)
141 		return -1;
142 
143 	err = bpf_obj_get_info_by_fd(fd, info, info_len);
144 	if (err) {
145 		p_err("can't get map info: %s", strerror(errno));
146 		close(fd);
147 		return err;
148 	}
149 
150 	return fd;
151 }
152 
153 static void print_entry_json(struct bpf_map_info *info, unsigned char *key,
154 			     unsigned char *value)
155 {
156 	jsonw_start_object(json_wtr);
157 
158 	if (!map_is_per_cpu(info->type)) {
159 		jsonw_name(json_wtr, "key");
160 		print_hex_data_json(key, info->key_size);
161 		jsonw_name(json_wtr, "value");
162 		print_hex_data_json(value, info->value_size);
163 	} else {
164 		unsigned int i, n;
165 
166 		n = get_possible_cpus();
167 
168 		jsonw_name(json_wtr, "key");
169 		print_hex_data_json(key, info->key_size);
170 
171 		jsonw_name(json_wtr, "values");
172 		jsonw_start_array(json_wtr);
173 		for (i = 0; i < n; i++) {
174 			jsonw_start_object(json_wtr);
175 
176 			jsonw_int_field(json_wtr, "cpu", i);
177 
178 			jsonw_name(json_wtr, "value");
179 			print_hex_data_json(value + i * info->value_size,
180 					    info->value_size);
181 
182 			jsonw_end_object(json_wtr);
183 		}
184 		jsonw_end_array(json_wtr);
185 	}
186 
187 	jsonw_end_object(json_wtr);
188 }
189 
190 static void print_entry_plain(struct bpf_map_info *info, unsigned char *key,
191 			      unsigned char *value)
192 {
193 	if (!map_is_per_cpu(info->type)) {
194 		bool single_line, break_names;
195 
196 		break_names = info->key_size > 16 || info->value_size > 16;
197 		single_line = info->key_size + info->value_size <= 24 &&
198 			!break_names;
199 
200 		printf("key:%c", break_names ? '\n' : ' ');
201 		fprint_hex(stdout, key, info->key_size, " ");
202 
203 		printf(single_line ? "  " : "\n");
204 
205 		printf("value:%c", break_names ? '\n' : ' ');
206 		fprint_hex(stdout, value, info->value_size, " ");
207 
208 		printf("\n");
209 	} else {
210 		unsigned int i, n;
211 
212 		n = get_possible_cpus();
213 
214 		printf("key:\n");
215 		fprint_hex(stdout, key, info->key_size, " ");
216 		printf("\n");
217 		for (i = 0; i < n; i++) {
218 			printf("value (CPU %02d):%c",
219 			       i, info->value_size > 16 ? '\n' : ' ');
220 			fprint_hex(stdout, value + i * info->value_size,
221 				   info->value_size, " ");
222 			printf("\n");
223 		}
224 	}
225 }
226 
227 static char **parse_bytes(char **argv, const char *name, unsigned char *val,
228 			  unsigned int n)
229 {
230 	unsigned int i = 0, base = 0;
231 	char *endptr;
232 
233 	if (is_prefix(*argv, "hex")) {
234 		base = 16;
235 		argv++;
236 	}
237 
238 	while (i < n && argv[i]) {
239 		val[i] = strtoul(argv[i], &endptr, base);
240 		if (*endptr) {
241 			p_err("error parsing byte: %s", argv[i]);
242 			return NULL;
243 		}
244 		i++;
245 	}
246 
247 	if (i != n) {
248 		p_err("%s expected %d bytes got %d", name, n, i);
249 		return NULL;
250 	}
251 
252 	return argv + i;
253 }
254 
255 static int parse_elem(char **argv, struct bpf_map_info *info,
256 		      void *key, void *value, __u32 key_size, __u32 value_size,
257 		      __u32 *flags, __u32 **value_fd)
258 {
259 	if (!*argv) {
260 		if (!key && !value)
261 			return 0;
262 		p_err("did not find %s", key ? "key" : "value");
263 		return -1;
264 	}
265 
266 	if (is_prefix(*argv, "key")) {
267 		if (!key) {
268 			if (key_size)
269 				p_err("duplicate key");
270 			else
271 				p_err("unnecessary key");
272 			return -1;
273 		}
274 
275 		argv = parse_bytes(argv + 1, "key", key, key_size);
276 		if (!argv)
277 			return -1;
278 
279 		return parse_elem(argv, info, NULL, value, key_size, value_size,
280 				  flags, value_fd);
281 	} else if (is_prefix(*argv, "value")) {
282 		int fd;
283 
284 		if (!value) {
285 			if (value_size)
286 				p_err("duplicate value");
287 			else
288 				p_err("unnecessary value");
289 			return -1;
290 		}
291 
292 		argv++;
293 
294 		if (map_is_map_of_maps(info->type)) {
295 			int argc = 2;
296 
297 			if (value_size != 4) {
298 				p_err("value smaller than 4B for map in map?");
299 				return -1;
300 			}
301 			if (!argv[0] || !argv[1]) {
302 				p_err("not enough value arguments for map in map");
303 				return -1;
304 			}
305 
306 			fd = map_parse_fd(&argc, &argv);
307 			if (fd < 0)
308 				return -1;
309 
310 			*value_fd = value;
311 			**value_fd = fd;
312 		} else if (map_is_map_of_progs(info->type)) {
313 			int argc = 2;
314 
315 			if (value_size != 4) {
316 				p_err("value smaller than 4B for map of progs?");
317 				return -1;
318 			}
319 			if (!argv[0] || !argv[1]) {
320 				p_err("not enough value arguments for map of progs");
321 				return -1;
322 			}
323 
324 			fd = prog_parse_fd(&argc, &argv);
325 			if (fd < 0)
326 				return -1;
327 
328 			*value_fd = value;
329 			**value_fd = fd;
330 		} else {
331 			argv = parse_bytes(argv, "value", value, value_size);
332 			if (!argv)
333 				return -1;
334 		}
335 
336 		return parse_elem(argv, info, key, NULL, key_size, value_size,
337 				  flags, NULL);
338 	} else if (is_prefix(*argv, "any") || is_prefix(*argv, "noexist") ||
339 		   is_prefix(*argv, "exist")) {
340 		if (!flags) {
341 			p_err("flags specified multiple times: %s", *argv);
342 			return -1;
343 		}
344 
345 		if (is_prefix(*argv, "any"))
346 			*flags = BPF_ANY;
347 		else if (is_prefix(*argv, "noexist"))
348 			*flags = BPF_NOEXIST;
349 		else if (is_prefix(*argv, "exist"))
350 			*flags = BPF_EXIST;
351 
352 		return parse_elem(argv + 1, info, key, value, key_size,
353 				  value_size, NULL, value_fd);
354 	}
355 
356 	p_err("expected key or value, got: %s", *argv);
357 	return -1;
358 }
359 
360 static int show_map_close_json(int fd, struct bpf_map_info *info)
361 {
362 	char *memlock;
363 
364 	memlock = get_fdinfo(fd, "memlock");
365 	close(fd);
366 
367 	jsonw_start_object(json_wtr);
368 
369 	jsonw_uint_field(json_wtr, "id", info->id);
370 	if (info->type < ARRAY_SIZE(map_type_name))
371 		jsonw_string_field(json_wtr, "type",
372 				   map_type_name[info->type]);
373 	else
374 		jsonw_uint_field(json_wtr, "type", info->type);
375 
376 	if (*info->name)
377 		jsonw_string_field(json_wtr, "name", info->name);
378 
379 	jsonw_name(json_wtr, "flags");
380 	jsonw_printf(json_wtr, "%d", info->map_flags);
381 
382 	print_dev_json(info->ifindex, info->netns_dev, info->netns_ino);
383 
384 	jsonw_uint_field(json_wtr, "bytes_key", info->key_size);
385 	jsonw_uint_field(json_wtr, "bytes_value", info->value_size);
386 	jsonw_uint_field(json_wtr, "max_entries", info->max_entries);
387 
388 	if (memlock)
389 		jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
390 	free(memlock);
391 
392 	if (!hash_empty(map_table.table)) {
393 		struct pinned_obj *obj;
394 
395 		jsonw_name(json_wtr, "pinned");
396 		jsonw_start_array(json_wtr);
397 		hash_for_each_possible(map_table.table, obj, hash, info->id) {
398 			if (obj->id == info->id)
399 				jsonw_string(json_wtr, obj->path);
400 		}
401 		jsonw_end_array(json_wtr);
402 	}
403 
404 	jsonw_end_object(json_wtr);
405 
406 	return 0;
407 }
408 
409 static int show_map_close_plain(int fd, struct bpf_map_info *info)
410 {
411 	char *memlock;
412 
413 	memlock = get_fdinfo(fd, "memlock");
414 	close(fd);
415 
416 	printf("%u: ", info->id);
417 	if (info->type < ARRAY_SIZE(map_type_name))
418 		printf("%s  ", map_type_name[info->type]);
419 	else
420 		printf("type %u  ", info->type);
421 
422 	if (*info->name)
423 		printf("name %s  ", info->name);
424 
425 	printf("flags 0x%x", info->map_flags);
426 	print_dev_plain(info->ifindex, info->netns_dev, info->netns_ino);
427 	printf("\n");
428 	printf("\tkey %uB  value %uB  max_entries %u",
429 	       info->key_size, info->value_size, info->max_entries);
430 
431 	if (memlock)
432 		printf("  memlock %sB", memlock);
433 	free(memlock);
434 
435 	printf("\n");
436 	if (!hash_empty(map_table.table)) {
437 		struct pinned_obj *obj;
438 
439 		hash_for_each_possible(map_table.table, obj, hash, info->id) {
440 			if (obj->id == info->id)
441 				printf("\tpinned %s\n", obj->path);
442 		}
443 	}
444 	return 0;
445 }
446 
447 static int do_show(int argc, char **argv)
448 {
449 	struct bpf_map_info info = {};
450 	__u32 len = sizeof(info);
451 	__u32 id = 0;
452 	int err;
453 	int fd;
454 
455 	if (show_pinned)
456 		build_pinned_obj_table(&map_table, BPF_OBJ_MAP);
457 
458 	if (argc == 2) {
459 		fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
460 		if (fd < 0)
461 			return -1;
462 
463 		if (json_output)
464 			return show_map_close_json(fd, &info);
465 		else
466 			return show_map_close_plain(fd, &info);
467 	}
468 
469 	if (argc)
470 		return BAD_ARG();
471 
472 	if (json_output)
473 		jsonw_start_array(json_wtr);
474 	while (true) {
475 		err = bpf_map_get_next_id(id, &id);
476 		if (err) {
477 			if (errno == ENOENT)
478 				break;
479 			p_err("can't get next map: %s%s", strerror(errno),
480 			      errno == EINVAL ? " -- kernel too old?" : "");
481 			break;
482 		}
483 
484 		fd = bpf_map_get_fd_by_id(id);
485 		if (fd < 0) {
486 			if (errno == ENOENT)
487 				continue;
488 			p_err("can't get map by id (%u): %s",
489 			      id, strerror(errno));
490 			break;
491 		}
492 
493 		err = bpf_obj_get_info_by_fd(fd, &info, &len);
494 		if (err) {
495 			p_err("can't get map info: %s", strerror(errno));
496 			close(fd);
497 			break;
498 		}
499 
500 		if (json_output)
501 			show_map_close_json(fd, &info);
502 		else
503 			show_map_close_plain(fd, &info);
504 	}
505 	if (json_output)
506 		jsonw_end_array(json_wtr);
507 
508 	return errno == ENOENT ? 0 : -1;
509 }
510 
511 static int do_dump(int argc, char **argv)
512 {
513 	void *key, *value, *prev_key;
514 	unsigned int num_elems = 0;
515 	struct bpf_map_info info = {};
516 	__u32 len = sizeof(info);
517 	int err;
518 	int fd;
519 
520 	if (argc != 2)
521 		usage();
522 
523 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
524 	if (fd < 0)
525 		return -1;
526 
527 	if (map_is_map_of_maps(info.type) || map_is_map_of_progs(info.type)) {
528 		p_err("Dumping maps of maps and program maps not supported");
529 		close(fd);
530 		return -1;
531 	}
532 
533 	key = malloc(info.key_size);
534 	value = alloc_value(&info);
535 	if (!key || !value) {
536 		p_err("mem alloc failed");
537 		err = -1;
538 		goto exit_free;
539 	}
540 
541 	prev_key = NULL;
542 	if (json_output)
543 		jsonw_start_array(json_wtr);
544 	while (true) {
545 		err = bpf_map_get_next_key(fd, prev_key, key);
546 		if (err) {
547 			if (errno == ENOENT)
548 				err = 0;
549 			break;
550 		}
551 
552 		if (!bpf_map_lookup_elem(fd, key, value)) {
553 			if (json_output)
554 				print_entry_json(&info, key, value);
555 			else
556 				print_entry_plain(&info, key, value);
557 		} else {
558 			if (json_output) {
559 				jsonw_name(json_wtr, "key");
560 				print_hex_data_json(key, info.key_size);
561 				jsonw_name(json_wtr, "value");
562 				jsonw_start_object(json_wtr);
563 				jsonw_string_field(json_wtr, "error",
564 						   "can't lookup element");
565 				jsonw_end_object(json_wtr);
566 			} else {
567 				p_info("can't lookup element with key: ");
568 				fprint_hex(stderr, key, info.key_size, " ");
569 				fprintf(stderr, "\n");
570 			}
571 		}
572 
573 		prev_key = key;
574 		num_elems++;
575 	}
576 
577 	if (json_output)
578 		jsonw_end_array(json_wtr);
579 	else
580 		printf("Found %u element%s\n", num_elems,
581 		       num_elems != 1 ? "s" : "");
582 
583 exit_free:
584 	free(key);
585 	free(value);
586 	close(fd);
587 
588 	return err;
589 }
590 
591 static int do_update(int argc, char **argv)
592 {
593 	struct bpf_map_info info = {};
594 	__u32 len = sizeof(info);
595 	__u32 *value_fd = NULL;
596 	__u32 flags = BPF_ANY;
597 	void *key, *value;
598 	int fd, err;
599 
600 	if (argc < 2)
601 		usage();
602 
603 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
604 	if (fd < 0)
605 		return -1;
606 
607 	key = malloc(info.key_size);
608 	value = alloc_value(&info);
609 	if (!key || !value) {
610 		p_err("mem alloc failed");
611 		err = -1;
612 		goto exit_free;
613 	}
614 
615 	err = parse_elem(argv, &info, key, value, info.key_size,
616 			 info.value_size, &flags, &value_fd);
617 	if (err)
618 		goto exit_free;
619 
620 	err = bpf_map_update_elem(fd, key, value, flags);
621 	if (err) {
622 		p_err("update failed: %s", strerror(errno));
623 		goto exit_free;
624 	}
625 
626 exit_free:
627 	if (value_fd)
628 		close(*value_fd);
629 	free(key);
630 	free(value);
631 	close(fd);
632 
633 	if (!err && json_output)
634 		jsonw_null(json_wtr);
635 	return err;
636 }
637 
638 static int do_lookup(int argc, char **argv)
639 {
640 	struct bpf_map_info info = {};
641 	__u32 len = sizeof(info);
642 	void *key, *value;
643 	int err;
644 	int fd;
645 
646 	if (argc < 2)
647 		usage();
648 
649 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
650 	if (fd < 0)
651 		return -1;
652 
653 	key = malloc(info.key_size);
654 	value = alloc_value(&info);
655 	if (!key || !value) {
656 		p_err("mem alloc failed");
657 		err = -1;
658 		goto exit_free;
659 	}
660 
661 	err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
662 	if (err)
663 		goto exit_free;
664 
665 	err = bpf_map_lookup_elem(fd, key, value);
666 	if (!err) {
667 		if (json_output)
668 			print_entry_json(&info, key, value);
669 		else
670 			print_entry_plain(&info, key, value);
671 	} else if (errno == ENOENT) {
672 		if (json_output) {
673 			jsonw_null(json_wtr);
674 		} else {
675 			printf("key:\n");
676 			fprint_hex(stdout, key, info.key_size, " ");
677 			printf("\n\nNot found\n");
678 		}
679 	} else {
680 		p_err("lookup failed: %s", strerror(errno));
681 	}
682 
683 exit_free:
684 	free(key);
685 	free(value);
686 	close(fd);
687 
688 	return err;
689 }
690 
691 static int do_getnext(int argc, char **argv)
692 {
693 	struct bpf_map_info info = {};
694 	__u32 len = sizeof(info);
695 	void *key, *nextkey;
696 	int err;
697 	int fd;
698 
699 	if (argc < 2)
700 		usage();
701 
702 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
703 	if (fd < 0)
704 		return -1;
705 
706 	key = malloc(info.key_size);
707 	nextkey = malloc(info.key_size);
708 	if (!key || !nextkey) {
709 		p_err("mem alloc failed");
710 		err = -1;
711 		goto exit_free;
712 	}
713 
714 	if (argc) {
715 		err = parse_elem(argv, &info, key, NULL, info.key_size, 0,
716 				 NULL, NULL);
717 		if (err)
718 			goto exit_free;
719 	} else {
720 		free(key);
721 		key = NULL;
722 	}
723 
724 	err = bpf_map_get_next_key(fd, key, nextkey);
725 	if (err) {
726 		p_err("can't get next key: %s", strerror(errno));
727 		goto exit_free;
728 	}
729 
730 	if (json_output) {
731 		jsonw_start_object(json_wtr);
732 		if (key) {
733 			jsonw_name(json_wtr, "key");
734 			print_hex_data_json(key, info.key_size);
735 		} else {
736 			jsonw_null_field(json_wtr, "key");
737 		}
738 		jsonw_name(json_wtr, "next_key");
739 		print_hex_data_json(nextkey, info.key_size);
740 		jsonw_end_object(json_wtr);
741 	} else {
742 		if (key) {
743 			printf("key:\n");
744 			fprint_hex(stdout, key, info.key_size, " ");
745 			printf("\n");
746 		} else {
747 			printf("key: None\n");
748 		}
749 		printf("next key:\n");
750 		fprint_hex(stdout, nextkey, info.key_size, " ");
751 		printf("\n");
752 	}
753 
754 exit_free:
755 	free(nextkey);
756 	free(key);
757 	close(fd);
758 
759 	return err;
760 }
761 
762 static int do_delete(int argc, char **argv)
763 {
764 	struct bpf_map_info info = {};
765 	__u32 len = sizeof(info);
766 	void *key;
767 	int err;
768 	int fd;
769 
770 	if (argc < 2)
771 		usage();
772 
773 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
774 	if (fd < 0)
775 		return -1;
776 
777 	key = malloc(info.key_size);
778 	if (!key) {
779 		p_err("mem alloc failed");
780 		err = -1;
781 		goto exit_free;
782 	}
783 
784 	err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
785 	if (err)
786 		goto exit_free;
787 
788 	err = bpf_map_delete_elem(fd, key);
789 	if (err)
790 		p_err("delete failed: %s", strerror(errno));
791 
792 exit_free:
793 	free(key);
794 	close(fd);
795 
796 	if (!err && json_output)
797 		jsonw_null(json_wtr);
798 	return err;
799 }
800 
801 static int do_pin(int argc, char **argv)
802 {
803 	int err;
804 
805 	err = do_pin_any(argc, argv, bpf_map_get_fd_by_id);
806 	if (!err && json_output)
807 		jsonw_null(json_wtr);
808 	return err;
809 }
810 
811 static int do_help(int argc, char **argv)
812 {
813 	if (json_output) {
814 		jsonw_null(json_wtr);
815 		return 0;
816 	}
817 
818 	fprintf(stderr,
819 		"Usage: %s %s { show | list }   [MAP]\n"
820 		"       %s %s dump       MAP\n"
821 		"       %s %s update     MAP  key DATA value VALUE [UPDATE_FLAGS]\n"
822 		"       %s %s lookup     MAP  key DATA\n"
823 		"       %s %s getnext    MAP [key DATA]\n"
824 		"       %s %s delete     MAP  key DATA\n"
825 		"       %s %s pin        MAP  FILE\n"
826 		"       %s %s event_pipe MAP [cpu N index M]\n"
827 		"       %s %s help\n"
828 		"\n"
829 		"       MAP := { id MAP_ID | pinned FILE }\n"
830 		"       DATA := { [hex] BYTES }\n"
831 		"       " HELP_SPEC_PROGRAM "\n"
832 		"       VALUE := { DATA | MAP | PROG }\n"
833 		"       UPDATE_FLAGS := { any | exist | noexist }\n"
834 		"       " HELP_SPEC_OPTIONS "\n"
835 		"",
836 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
837 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
838 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]);
839 
840 	return 0;
841 }
842 
843 static const struct cmd cmds[] = {
844 	{ "show",	do_show },
845 	{ "list",	do_show },
846 	{ "help",	do_help },
847 	{ "dump",	do_dump },
848 	{ "update",	do_update },
849 	{ "lookup",	do_lookup },
850 	{ "getnext",	do_getnext },
851 	{ "delete",	do_delete },
852 	{ "pin",	do_pin },
853 	{ "event_pipe",	do_event_pipe },
854 	{ 0 }
855 };
856 
857 int do_map(int argc, char **argv)
858 {
859 	return cmd_select(cmds, argc, argv, do_help);
860 }
861