xref: /openbmc/linux/tools/bpf/bpftool/map.c (revision feac8c8b)
1 /*
2  * Copyright (C) 2017 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 <ctype.h>
38 #include <errno.h>
39 #include <fcntl.h>
40 #include <stdbool.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 #include <sys/types.h>
46 #include <sys/stat.h>
47 
48 #include <bpf.h>
49 
50 #include "main.h"
51 
52 static const char * const map_type_name[] = {
53 	[BPF_MAP_TYPE_UNSPEC]		= "unspec",
54 	[BPF_MAP_TYPE_HASH]		= "hash",
55 	[BPF_MAP_TYPE_ARRAY]		= "array",
56 	[BPF_MAP_TYPE_PROG_ARRAY]	= "prog_array",
57 	[BPF_MAP_TYPE_PERF_EVENT_ARRAY]	= "perf_event_array",
58 	[BPF_MAP_TYPE_PERCPU_HASH]	= "percpu_hash",
59 	[BPF_MAP_TYPE_PERCPU_ARRAY]	= "percpu_array",
60 	[BPF_MAP_TYPE_STACK_TRACE]	= "stack_trace",
61 	[BPF_MAP_TYPE_CGROUP_ARRAY]	= "cgroup_array",
62 	[BPF_MAP_TYPE_LRU_HASH]		= "lru_hash",
63 	[BPF_MAP_TYPE_LRU_PERCPU_HASH]	= "lru_percpu_hash",
64 	[BPF_MAP_TYPE_LPM_TRIE]		= "lpm_trie",
65 	[BPF_MAP_TYPE_ARRAY_OF_MAPS]	= "array_of_maps",
66 	[BPF_MAP_TYPE_HASH_OF_MAPS]	= "hash_of_maps",
67 	[BPF_MAP_TYPE_DEVMAP]		= "devmap",
68 	[BPF_MAP_TYPE_SOCKMAP]		= "sockmap",
69 	[BPF_MAP_TYPE_CPUMAP]		= "cpumap",
70 };
71 
72 static unsigned int get_possible_cpus(void)
73 {
74 	static unsigned int result;
75 	char buf[128];
76 	long int n;
77 	char *ptr;
78 	int fd;
79 
80 	if (result)
81 		return result;
82 
83 	fd = open("/sys/devices/system/cpu/possible", O_RDONLY);
84 	if (fd < 0) {
85 		p_err("can't open sysfs possible cpus");
86 		exit(-1);
87 	}
88 
89 	n = read(fd, buf, sizeof(buf));
90 	if (n < 2) {
91 		p_err("can't read sysfs possible cpus");
92 		exit(-1);
93 	}
94 	close(fd);
95 
96 	if (n == sizeof(buf)) {
97 		p_err("read sysfs possible cpus overflow");
98 		exit(-1);
99 	}
100 
101 	ptr = buf;
102 	n = 0;
103 	while (*ptr && *ptr != '\n') {
104 		unsigned int a, b;
105 
106 		if (sscanf(ptr, "%u-%u", &a, &b) == 2) {
107 			n += b - a + 1;
108 
109 			ptr = strchr(ptr, '-') + 1;
110 		} else if (sscanf(ptr, "%u", &a) == 1) {
111 			n++;
112 		} else {
113 			assert(0);
114 		}
115 
116 		while (isdigit(*ptr))
117 			ptr++;
118 		if (*ptr == ',')
119 			ptr++;
120 	}
121 
122 	result = n;
123 
124 	return result;
125 }
126 
127 static bool map_is_per_cpu(__u32 type)
128 {
129 	return type == BPF_MAP_TYPE_PERCPU_HASH ||
130 	       type == BPF_MAP_TYPE_PERCPU_ARRAY ||
131 	       type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
132 }
133 
134 static bool map_is_map_of_maps(__u32 type)
135 {
136 	return type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
137 	       type == BPF_MAP_TYPE_HASH_OF_MAPS;
138 }
139 
140 static bool map_is_map_of_progs(__u32 type)
141 {
142 	return type == BPF_MAP_TYPE_PROG_ARRAY;
143 }
144 
145 static void *alloc_value(struct bpf_map_info *info)
146 {
147 	if (map_is_per_cpu(info->type))
148 		return malloc(info->value_size * get_possible_cpus());
149 	else
150 		return malloc(info->value_size);
151 }
152 
153 static int map_parse_fd(int *argc, char ***argv)
154 {
155 	int fd;
156 
157 	if (is_prefix(**argv, "id")) {
158 		unsigned int id;
159 		char *endptr;
160 
161 		NEXT_ARGP();
162 
163 		id = strtoul(**argv, &endptr, 0);
164 		if (*endptr) {
165 			p_err("can't parse %s as ID", **argv);
166 			return -1;
167 		}
168 		NEXT_ARGP();
169 
170 		fd = bpf_map_get_fd_by_id(id);
171 		if (fd < 0)
172 			p_err("get map by id (%u): %s", id, strerror(errno));
173 		return fd;
174 	} else if (is_prefix(**argv, "pinned")) {
175 		char *path;
176 
177 		NEXT_ARGP();
178 
179 		path = **argv;
180 		NEXT_ARGP();
181 
182 		return open_obj_pinned_any(path, BPF_OBJ_MAP);
183 	}
184 
185 	p_err("expected 'id' or 'pinned', got: '%s'?", **argv);
186 	return -1;
187 }
188 
189 static int
190 map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
191 {
192 	int err;
193 	int fd;
194 
195 	fd = map_parse_fd(argc, argv);
196 	if (fd < 0)
197 		return -1;
198 
199 	err = bpf_obj_get_info_by_fd(fd, info, info_len);
200 	if (err) {
201 		p_err("can't get map info: %s", strerror(errno));
202 		close(fd);
203 		return err;
204 	}
205 
206 	return fd;
207 }
208 
209 static void print_entry_json(struct bpf_map_info *info, unsigned char *key,
210 			     unsigned char *value)
211 {
212 	jsonw_start_object(json_wtr);
213 
214 	if (!map_is_per_cpu(info->type)) {
215 		jsonw_name(json_wtr, "key");
216 		print_hex_data_json(key, info->key_size);
217 		jsonw_name(json_wtr, "value");
218 		print_hex_data_json(value, info->value_size);
219 	} else {
220 		unsigned int i, n;
221 
222 		n = get_possible_cpus();
223 
224 		jsonw_name(json_wtr, "key");
225 		print_hex_data_json(key, info->key_size);
226 
227 		jsonw_name(json_wtr, "values");
228 		jsonw_start_array(json_wtr);
229 		for (i = 0; i < n; i++) {
230 			jsonw_start_object(json_wtr);
231 
232 			jsonw_int_field(json_wtr, "cpu", i);
233 
234 			jsonw_name(json_wtr, "value");
235 			print_hex_data_json(value + i * info->value_size,
236 					    info->value_size);
237 
238 			jsonw_end_object(json_wtr);
239 		}
240 		jsonw_end_array(json_wtr);
241 	}
242 
243 	jsonw_end_object(json_wtr);
244 }
245 
246 static void print_entry_plain(struct bpf_map_info *info, unsigned char *key,
247 			      unsigned char *value)
248 {
249 	if (!map_is_per_cpu(info->type)) {
250 		bool single_line, break_names;
251 
252 		break_names = info->key_size > 16 || info->value_size > 16;
253 		single_line = info->key_size + info->value_size <= 24 &&
254 			!break_names;
255 
256 		printf("key:%c", break_names ? '\n' : ' ');
257 		fprint_hex(stdout, key, info->key_size, " ");
258 
259 		printf(single_line ? "  " : "\n");
260 
261 		printf("value:%c", break_names ? '\n' : ' ');
262 		fprint_hex(stdout, value, info->value_size, " ");
263 
264 		printf("\n");
265 	} else {
266 		unsigned int i, n;
267 
268 		n = get_possible_cpus();
269 
270 		printf("key:\n");
271 		fprint_hex(stdout, key, info->key_size, " ");
272 		printf("\n");
273 		for (i = 0; i < n; i++) {
274 			printf("value (CPU %02d):%c",
275 			       i, info->value_size > 16 ? '\n' : ' ');
276 			fprint_hex(stdout, value + i * info->value_size,
277 				   info->value_size, " ");
278 			printf("\n");
279 		}
280 	}
281 }
282 
283 static char **parse_bytes(char **argv, const char *name, unsigned char *val,
284 			  unsigned int n)
285 {
286 	unsigned int i = 0;
287 	char *endptr;
288 
289 	while (i < n && argv[i]) {
290 		val[i] = strtoul(argv[i], &endptr, 0);
291 		if (*endptr) {
292 			p_err("error parsing byte: %s", argv[i]);
293 			return NULL;
294 		}
295 		i++;
296 	}
297 
298 	if (i != n) {
299 		p_err("%s expected %d bytes got %d", name, n, i);
300 		return NULL;
301 	}
302 
303 	return argv + i;
304 }
305 
306 static int parse_elem(char **argv, struct bpf_map_info *info,
307 		      void *key, void *value, __u32 key_size, __u32 value_size,
308 		      __u32 *flags, __u32 **value_fd)
309 {
310 	if (!*argv) {
311 		if (!key && !value)
312 			return 0;
313 		p_err("did not find %s", key ? "key" : "value");
314 		return -1;
315 	}
316 
317 	if (is_prefix(*argv, "key")) {
318 		if (!key) {
319 			if (key_size)
320 				p_err("duplicate key");
321 			else
322 				p_err("unnecessary key");
323 			return -1;
324 		}
325 
326 		argv = parse_bytes(argv + 1, "key", key, key_size);
327 		if (!argv)
328 			return -1;
329 
330 		return parse_elem(argv, info, NULL, value, key_size, value_size,
331 				  flags, value_fd);
332 	} else if (is_prefix(*argv, "value")) {
333 		int fd;
334 
335 		if (!value) {
336 			if (value_size)
337 				p_err("duplicate value");
338 			else
339 				p_err("unnecessary value");
340 			return -1;
341 		}
342 
343 		argv++;
344 
345 		if (map_is_map_of_maps(info->type)) {
346 			int argc = 2;
347 
348 			if (value_size != 4) {
349 				p_err("value smaller than 4B for map in map?");
350 				return -1;
351 			}
352 			if (!argv[0] || !argv[1]) {
353 				p_err("not enough value arguments for map in map");
354 				return -1;
355 			}
356 
357 			fd = map_parse_fd(&argc, &argv);
358 			if (fd < 0)
359 				return -1;
360 
361 			*value_fd = value;
362 			**value_fd = fd;
363 		} else if (map_is_map_of_progs(info->type)) {
364 			int argc = 2;
365 
366 			if (value_size != 4) {
367 				p_err("value smaller than 4B for map of progs?");
368 				return -1;
369 			}
370 			if (!argv[0] || !argv[1]) {
371 				p_err("not enough value arguments for map of progs");
372 				return -1;
373 			}
374 
375 			fd = prog_parse_fd(&argc, &argv);
376 			if (fd < 0)
377 				return -1;
378 
379 			*value_fd = value;
380 			**value_fd = fd;
381 		} else {
382 			argv = parse_bytes(argv, "value", value, value_size);
383 			if (!argv)
384 				return -1;
385 		}
386 
387 		return parse_elem(argv, info, key, NULL, key_size, value_size,
388 				  flags, NULL);
389 	} else if (is_prefix(*argv, "any") || is_prefix(*argv, "noexist") ||
390 		   is_prefix(*argv, "exist")) {
391 		if (!flags) {
392 			p_err("flags specified multiple times: %s", *argv);
393 			return -1;
394 		}
395 
396 		if (is_prefix(*argv, "any"))
397 			*flags = BPF_ANY;
398 		else if (is_prefix(*argv, "noexist"))
399 			*flags = BPF_NOEXIST;
400 		else if (is_prefix(*argv, "exist"))
401 			*flags = BPF_EXIST;
402 
403 		return parse_elem(argv + 1, info, key, value, key_size,
404 				  value_size, NULL, value_fd);
405 	}
406 
407 	p_err("expected key or value, got: %s", *argv);
408 	return -1;
409 }
410 
411 static int show_map_close_json(int fd, struct bpf_map_info *info)
412 {
413 	char *memlock;
414 
415 	memlock = get_fdinfo(fd, "memlock");
416 	close(fd);
417 
418 	jsonw_start_object(json_wtr);
419 
420 	jsonw_uint_field(json_wtr, "id", info->id);
421 	if (info->type < ARRAY_SIZE(map_type_name))
422 		jsonw_string_field(json_wtr, "type",
423 				   map_type_name[info->type]);
424 	else
425 		jsonw_uint_field(json_wtr, "type", info->type);
426 
427 	if (*info->name)
428 		jsonw_string_field(json_wtr, "name", info->name);
429 
430 	jsonw_name(json_wtr, "flags");
431 	jsonw_printf(json_wtr, "%#x", info->map_flags);
432 
433 	print_dev_json(info->ifindex, info->netns_dev, info->netns_ino);
434 
435 	jsonw_uint_field(json_wtr, "bytes_key", info->key_size);
436 	jsonw_uint_field(json_wtr, "bytes_value", info->value_size);
437 	jsonw_uint_field(json_wtr, "max_entries", info->max_entries);
438 
439 	if (memlock)
440 		jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
441 	free(memlock);
442 
443 	if (!hash_empty(map_table.table)) {
444 		struct pinned_obj *obj;
445 
446 		jsonw_name(json_wtr, "pinned");
447 		jsonw_start_array(json_wtr);
448 		hash_for_each_possible(map_table.table, obj, hash, info->id) {
449 			if (obj->id == info->id)
450 				jsonw_string(json_wtr, obj->path);
451 		}
452 		jsonw_end_array(json_wtr);
453 	}
454 
455 	jsonw_end_object(json_wtr);
456 
457 	return 0;
458 }
459 
460 static int show_map_close_plain(int fd, struct bpf_map_info *info)
461 {
462 	char *memlock;
463 
464 	memlock = get_fdinfo(fd, "memlock");
465 	close(fd);
466 
467 	printf("%u: ", info->id);
468 	if (info->type < ARRAY_SIZE(map_type_name))
469 		printf("%s  ", map_type_name[info->type]);
470 	else
471 		printf("type %u  ", info->type);
472 
473 	if (*info->name)
474 		printf("name %s  ", info->name);
475 
476 	printf("flags 0x%x", info->map_flags);
477 	print_dev_plain(info->ifindex, info->netns_dev, info->netns_ino);
478 	printf("\n");
479 	printf("\tkey %uB  value %uB  max_entries %u",
480 	       info->key_size, info->value_size, info->max_entries);
481 
482 	if (memlock)
483 		printf("  memlock %sB", memlock);
484 	free(memlock);
485 
486 	printf("\n");
487 	if (!hash_empty(map_table.table)) {
488 		struct pinned_obj *obj;
489 
490 		hash_for_each_possible(map_table.table, obj, hash, info->id) {
491 			if (obj->id == info->id)
492 				printf("\tpinned %s\n", obj->path);
493 		}
494 	}
495 	return 0;
496 }
497 
498 static int do_show(int argc, char **argv)
499 {
500 	struct bpf_map_info info = {};
501 	__u32 len = sizeof(info);
502 	__u32 id = 0;
503 	int err;
504 	int fd;
505 
506 	if (show_pinned)
507 		build_pinned_obj_table(&map_table, BPF_OBJ_MAP);
508 
509 	if (argc == 2) {
510 		fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
511 		if (fd < 0)
512 			return -1;
513 
514 		if (json_output)
515 			return show_map_close_json(fd, &info);
516 		else
517 			return show_map_close_plain(fd, &info);
518 	}
519 
520 	if (argc)
521 		return BAD_ARG();
522 
523 	if (json_output)
524 		jsonw_start_array(json_wtr);
525 	while (true) {
526 		err = bpf_map_get_next_id(id, &id);
527 		if (err) {
528 			if (errno == ENOENT)
529 				break;
530 			p_err("can't get next map: %s%s", strerror(errno),
531 			      errno == EINVAL ? " -- kernel too old?" : "");
532 			break;
533 		}
534 
535 		fd = bpf_map_get_fd_by_id(id);
536 		if (fd < 0) {
537 			if (errno == ENOENT)
538 				continue;
539 			p_err("can't get map by id (%u): %s",
540 			      id, strerror(errno));
541 			break;
542 		}
543 
544 		err = bpf_obj_get_info_by_fd(fd, &info, &len);
545 		if (err) {
546 			p_err("can't get map info: %s", strerror(errno));
547 			close(fd);
548 			break;
549 		}
550 
551 		if (json_output)
552 			show_map_close_json(fd, &info);
553 		else
554 			show_map_close_plain(fd, &info);
555 	}
556 	if (json_output)
557 		jsonw_end_array(json_wtr);
558 
559 	return errno == ENOENT ? 0 : -1;
560 }
561 
562 static int do_dump(int argc, char **argv)
563 {
564 	void *key, *value, *prev_key;
565 	unsigned int num_elems = 0;
566 	struct bpf_map_info info = {};
567 	__u32 len = sizeof(info);
568 	int err;
569 	int fd;
570 
571 	if (argc != 2)
572 		usage();
573 
574 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
575 	if (fd < 0)
576 		return -1;
577 
578 	if (map_is_map_of_maps(info.type) || map_is_map_of_progs(info.type)) {
579 		p_err("Dumping maps of maps and program maps not supported");
580 		close(fd);
581 		return -1;
582 	}
583 
584 	key = malloc(info.key_size);
585 	value = alloc_value(&info);
586 	if (!key || !value) {
587 		p_err("mem alloc failed");
588 		err = -1;
589 		goto exit_free;
590 	}
591 
592 	prev_key = NULL;
593 	if (json_output)
594 		jsonw_start_array(json_wtr);
595 	while (true) {
596 		err = bpf_map_get_next_key(fd, prev_key, key);
597 		if (err) {
598 			if (errno == ENOENT)
599 				err = 0;
600 			break;
601 		}
602 
603 		if (!bpf_map_lookup_elem(fd, key, value)) {
604 			if (json_output)
605 				print_entry_json(&info, key, value);
606 			else
607 				print_entry_plain(&info, key, value);
608 		} else {
609 			if (json_output) {
610 				jsonw_name(json_wtr, "key");
611 				print_hex_data_json(key, info.key_size);
612 				jsonw_name(json_wtr, "value");
613 				jsonw_start_object(json_wtr);
614 				jsonw_string_field(json_wtr, "error",
615 						   "can't lookup element");
616 				jsonw_end_object(json_wtr);
617 			} else {
618 				p_info("can't lookup element with key: ");
619 				fprint_hex(stderr, key, info.key_size, " ");
620 				fprintf(stderr, "\n");
621 			}
622 		}
623 
624 		prev_key = key;
625 		num_elems++;
626 	}
627 
628 	if (json_output)
629 		jsonw_end_array(json_wtr);
630 	else
631 		printf("Found %u element%s\n", num_elems,
632 		       num_elems != 1 ? "s" : "");
633 
634 exit_free:
635 	free(key);
636 	free(value);
637 	close(fd);
638 
639 	return err;
640 }
641 
642 static int do_update(int argc, char **argv)
643 {
644 	struct bpf_map_info info = {};
645 	__u32 len = sizeof(info);
646 	__u32 *value_fd = NULL;
647 	__u32 flags = BPF_ANY;
648 	void *key, *value;
649 	int fd, err;
650 
651 	if (argc < 2)
652 		usage();
653 
654 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
655 	if (fd < 0)
656 		return -1;
657 
658 	key = malloc(info.key_size);
659 	value = alloc_value(&info);
660 	if (!key || !value) {
661 		p_err("mem alloc failed");
662 		err = -1;
663 		goto exit_free;
664 	}
665 
666 	err = parse_elem(argv, &info, key, value, info.key_size,
667 			 info.value_size, &flags, &value_fd);
668 	if (err)
669 		goto exit_free;
670 
671 	err = bpf_map_update_elem(fd, key, value, flags);
672 	if (err) {
673 		p_err("update failed: %s", strerror(errno));
674 		goto exit_free;
675 	}
676 
677 exit_free:
678 	if (value_fd)
679 		close(*value_fd);
680 	free(key);
681 	free(value);
682 	close(fd);
683 
684 	if (!err && json_output)
685 		jsonw_null(json_wtr);
686 	return err;
687 }
688 
689 static int do_lookup(int argc, char **argv)
690 {
691 	struct bpf_map_info info = {};
692 	__u32 len = sizeof(info);
693 	void *key, *value;
694 	int err;
695 	int fd;
696 
697 	if (argc < 2)
698 		usage();
699 
700 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
701 	if (fd < 0)
702 		return -1;
703 
704 	key = malloc(info.key_size);
705 	value = alloc_value(&info);
706 	if (!key || !value) {
707 		p_err("mem alloc failed");
708 		err = -1;
709 		goto exit_free;
710 	}
711 
712 	err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
713 	if (err)
714 		goto exit_free;
715 
716 	err = bpf_map_lookup_elem(fd, key, value);
717 	if (!err) {
718 		if (json_output)
719 			print_entry_json(&info, key, value);
720 		else
721 			print_entry_plain(&info, key, value);
722 	} else if (errno == ENOENT) {
723 		if (json_output) {
724 			jsonw_null(json_wtr);
725 		} else {
726 			printf("key:\n");
727 			fprint_hex(stdout, key, info.key_size, " ");
728 			printf("\n\nNot found\n");
729 		}
730 	} else {
731 		p_err("lookup failed: %s", strerror(errno));
732 	}
733 
734 exit_free:
735 	free(key);
736 	free(value);
737 	close(fd);
738 
739 	return err;
740 }
741 
742 static int do_getnext(int argc, char **argv)
743 {
744 	struct bpf_map_info info = {};
745 	__u32 len = sizeof(info);
746 	void *key, *nextkey;
747 	int err;
748 	int fd;
749 
750 	if (argc < 2)
751 		usage();
752 
753 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
754 	if (fd < 0)
755 		return -1;
756 
757 	key = malloc(info.key_size);
758 	nextkey = malloc(info.key_size);
759 	if (!key || !nextkey) {
760 		p_err("mem alloc failed");
761 		err = -1;
762 		goto exit_free;
763 	}
764 
765 	if (argc) {
766 		err = parse_elem(argv, &info, key, NULL, info.key_size, 0,
767 				 NULL, NULL);
768 		if (err)
769 			goto exit_free;
770 	} else {
771 		free(key);
772 		key = NULL;
773 	}
774 
775 	err = bpf_map_get_next_key(fd, key, nextkey);
776 	if (err) {
777 		p_err("can't get next key: %s", strerror(errno));
778 		goto exit_free;
779 	}
780 
781 	if (json_output) {
782 		jsonw_start_object(json_wtr);
783 		if (key) {
784 			jsonw_name(json_wtr, "key");
785 			print_hex_data_json(key, info.key_size);
786 		} else {
787 			jsonw_null_field(json_wtr, "key");
788 		}
789 		jsonw_name(json_wtr, "next_key");
790 		print_hex_data_json(nextkey, info.key_size);
791 		jsonw_end_object(json_wtr);
792 	} else {
793 		if (key) {
794 			printf("key:\n");
795 			fprint_hex(stdout, key, info.key_size, " ");
796 			printf("\n");
797 		} else {
798 			printf("key: None\n");
799 		}
800 		printf("next key:\n");
801 		fprint_hex(stdout, nextkey, info.key_size, " ");
802 		printf("\n");
803 	}
804 
805 exit_free:
806 	free(nextkey);
807 	free(key);
808 	close(fd);
809 
810 	return err;
811 }
812 
813 static int do_delete(int argc, char **argv)
814 {
815 	struct bpf_map_info info = {};
816 	__u32 len = sizeof(info);
817 	void *key;
818 	int err;
819 	int fd;
820 
821 	if (argc < 2)
822 		usage();
823 
824 	fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
825 	if (fd < 0)
826 		return -1;
827 
828 	key = malloc(info.key_size);
829 	if (!key) {
830 		p_err("mem alloc failed");
831 		err = -1;
832 		goto exit_free;
833 	}
834 
835 	err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
836 	if (err)
837 		goto exit_free;
838 
839 	err = bpf_map_delete_elem(fd, key);
840 	if (err)
841 		p_err("delete failed: %s", strerror(errno));
842 
843 exit_free:
844 	free(key);
845 	close(fd);
846 
847 	if (!err && json_output)
848 		jsonw_null(json_wtr);
849 	return err;
850 }
851 
852 static int do_pin(int argc, char **argv)
853 {
854 	int err;
855 
856 	err = do_pin_any(argc, argv, bpf_map_get_fd_by_id);
857 	if (!err && json_output)
858 		jsonw_null(json_wtr);
859 	return err;
860 }
861 
862 static int do_help(int argc, char **argv)
863 {
864 	if (json_output) {
865 		jsonw_null(json_wtr);
866 		return 0;
867 	}
868 
869 	fprintf(stderr,
870 		"Usage: %s %s { show | list }   [MAP]\n"
871 		"       %s %s dump    MAP\n"
872 		"       %s %s update  MAP  key BYTES value VALUE [UPDATE_FLAGS]\n"
873 		"       %s %s lookup  MAP  key BYTES\n"
874 		"       %s %s getnext MAP [key BYTES]\n"
875 		"       %s %s delete  MAP  key BYTES\n"
876 		"       %s %s pin     MAP  FILE\n"
877 		"       %s %s help\n"
878 		"\n"
879 		"       MAP := { id MAP_ID | pinned FILE }\n"
880 		"       " HELP_SPEC_PROGRAM "\n"
881 		"       VALUE := { BYTES | MAP | PROG }\n"
882 		"       UPDATE_FLAGS := { any | exist | noexist }\n"
883 		"       " HELP_SPEC_OPTIONS "\n"
884 		"",
885 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
886 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
887 		bin_name, argv[-2], bin_name, argv[-2]);
888 
889 	return 0;
890 }
891 
892 static const struct cmd cmds[] = {
893 	{ "show",	do_show },
894 	{ "list",	do_show },
895 	{ "help",	do_help },
896 	{ "dump",	do_dump },
897 	{ "update",	do_update },
898 	{ "lookup",	do_lookup },
899 	{ "getnext",	do_getnext },
900 	{ "delete",	do_delete },
901 	{ "pin",	do_pin },
902 	{ 0 }
903 };
904 
905 int do_map(int argc, char **argv)
906 {
907 	return cmd_select(cmds, argc, argv, do_help);
908 }
909