tools: bpftool: make it easier to feed hex bytes to bpftool
[muen/linux.git] / tools / bpf / bpftool / map.c
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, base = 0;
287         char *endptr;
288
289         if (is_prefix(*argv, "hex")) {
290                 base = 16;
291                 argv++;
292         }
293
294         while (i < n && argv[i]) {
295                 val[i] = strtoul(argv[i], &endptr, base);
296                 if (*endptr) {
297                         p_err("error parsing byte: %s", argv[i]);
298                         return NULL;
299                 }
300                 i++;
301         }
302
303         if (i != n) {
304                 p_err("%s expected %d bytes got %d", name, n, i);
305                 return NULL;
306         }
307
308         return argv + i;
309 }
310
311 static int parse_elem(char **argv, struct bpf_map_info *info,
312                       void *key, void *value, __u32 key_size, __u32 value_size,
313                       __u32 *flags, __u32 **value_fd)
314 {
315         if (!*argv) {
316                 if (!key && !value)
317                         return 0;
318                 p_err("did not find %s", key ? "key" : "value");
319                 return -1;
320         }
321
322         if (is_prefix(*argv, "key")) {
323                 if (!key) {
324                         if (key_size)
325                                 p_err("duplicate key");
326                         else
327                                 p_err("unnecessary key");
328                         return -1;
329                 }
330
331                 argv = parse_bytes(argv + 1, "key", key, key_size);
332                 if (!argv)
333                         return -1;
334
335                 return parse_elem(argv, info, NULL, value, key_size, value_size,
336                                   flags, value_fd);
337         } else if (is_prefix(*argv, "value")) {
338                 int fd;
339
340                 if (!value) {
341                         if (value_size)
342                                 p_err("duplicate value");
343                         else
344                                 p_err("unnecessary value");
345                         return -1;
346                 }
347
348                 argv++;
349
350                 if (map_is_map_of_maps(info->type)) {
351                         int argc = 2;
352
353                         if (value_size != 4) {
354                                 p_err("value smaller than 4B for map in map?");
355                                 return -1;
356                         }
357                         if (!argv[0] || !argv[1]) {
358                                 p_err("not enough value arguments for map in map");
359                                 return -1;
360                         }
361
362                         fd = map_parse_fd(&argc, &argv);
363                         if (fd < 0)
364                                 return -1;
365
366                         *value_fd = value;
367                         **value_fd = fd;
368                 } else if (map_is_map_of_progs(info->type)) {
369                         int argc = 2;
370
371                         if (value_size != 4) {
372                                 p_err("value smaller than 4B for map of progs?");
373                                 return -1;
374                         }
375                         if (!argv[0] || !argv[1]) {
376                                 p_err("not enough value arguments for map of progs");
377                                 return -1;
378                         }
379
380                         fd = prog_parse_fd(&argc, &argv);
381                         if (fd < 0)
382                                 return -1;
383
384                         *value_fd = value;
385                         **value_fd = fd;
386                 } else {
387                         argv = parse_bytes(argv, "value", value, value_size);
388                         if (!argv)
389                                 return -1;
390                 }
391
392                 return parse_elem(argv, info, key, NULL, key_size, value_size,
393                                   flags, NULL);
394         } else if (is_prefix(*argv, "any") || is_prefix(*argv, "noexist") ||
395                    is_prefix(*argv, "exist")) {
396                 if (!flags) {
397                         p_err("flags specified multiple times: %s", *argv);
398                         return -1;
399                 }
400
401                 if (is_prefix(*argv, "any"))
402                         *flags = BPF_ANY;
403                 else if (is_prefix(*argv, "noexist"))
404                         *flags = BPF_NOEXIST;
405                 else if (is_prefix(*argv, "exist"))
406                         *flags = BPF_EXIST;
407
408                 return parse_elem(argv + 1, info, key, value, key_size,
409                                   value_size, NULL, value_fd);
410         }
411
412         p_err("expected key or value, got: %s", *argv);
413         return -1;
414 }
415
416 static int show_map_close_json(int fd, struct bpf_map_info *info)
417 {
418         char *memlock;
419
420         memlock = get_fdinfo(fd, "memlock");
421         close(fd);
422
423         jsonw_start_object(json_wtr);
424
425         jsonw_uint_field(json_wtr, "id", info->id);
426         if (info->type < ARRAY_SIZE(map_type_name))
427                 jsonw_string_field(json_wtr, "type",
428                                    map_type_name[info->type]);
429         else
430                 jsonw_uint_field(json_wtr, "type", info->type);
431
432         if (*info->name)
433                 jsonw_string_field(json_wtr, "name", info->name);
434
435         jsonw_name(json_wtr, "flags");
436         jsonw_printf(json_wtr, "%d", info->map_flags);
437
438         print_dev_json(info->ifindex, info->netns_dev, info->netns_ino);
439
440         jsonw_uint_field(json_wtr, "bytes_key", info->key_size);
441         jsonw_uint_field(json_wtr, "bytes_value", info->value_size);
442         jsonw_uint_field(json_wtr, "max_entries", info->max_entries);
443
444         if (memlock)
445                 jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
446         free(memlock);
447
448         if (!hash_empty(map_table.table)) {
449                 struct pinned_obj *obj;
450
451                 jsonw_name(json_wtr, "pinned");
452                 jsonw_start_array(json_wtr);
453                 hash_for_each_possible(map_table.table, obj, hash, info->id) {
454                         if (obj->id == info->id)
455                                 jsonw_string(json_wtr, obj->path);
456                 }
457                 jsonw_end_array(json_wtr);
458         }
459
460         jsonw_end_object(json_wtr);
461
462         return 0;
463 }
464
465 static int show_map_close_plain(int fd, struct bpf_map_info *info)
466 {
467         char *memlock;
468
469         memlock = get_fdinfo(fd, "memlock");
470         close(fd);
471
472         printf("%u: ", info->id);
473         if (info->type < ARRAY_SIZE(map_type_name))
474                 printf("%s  ", map_type_name[info->type]);
475         else
476                 printf("type %u  ", info->type);
477
478         if (*info->name)
479                 printf("name %s  ", info->name);
480
481         printf("flags 0x%x", info->map_flags);
482         print_dev_plain(info->ifindex, info->netns_dev, info->netns_ino);
483         printf("\n");
484         printf("\tkey %uB  value %uB  max_entries %u",
485                info->key_size, info->value_size, info->max_entries);
486
487         if (memlock)
488                 printf("  memlock %sB", memlock);
489         free(memlock);
490
491         printf("\n");
492         if (!hash_empty(map_table.table)) {
493                 struct pinned_obj *obj;
494
495                 hash_for_each_possible(map_table.table, obj, hash, info->id) {
496                         if (obj->id == info->id)
497                                 printf("\tpinned %s\n", obj->path);
498                 }
499         }
500         return 0;
501 }
502
503 static int do_show(int argc, char **argv)
504 {
505         struct bpf_map_info info = {};
506         __u32 len = sizeof(info);
507         __u32 id = 0;
508         int err;
509         int fd;
510
511         if (show_pinned)
512                 build_pinned_obj_table(&map_table, BPF_OBJ_MAP);
513
514         if (argc == 2) {
515                 fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
516                 if (fd < 0)
517                         return -1;
518
519                 if (json_output)
520                         return show_map_close_json(fd, &info);
521                 else
522                         return show_map_close_plain(fd, &info);
523         }
524
525         if (argc)
526                 return BAD_ARG();
527
528         if (json_output)
529                 jsonw_start_array(json_wtr);
530         while (true) {
531                 err = bpf_map_get_next_id(id, &id);
532                 if (err) {
533                         if (errno == ENOENT)
534                                 break;
535                         p_err("can't get next map: %s%s", strerror(errno),
536                               errno == EINVAL ? " -- kernel too old?" : "");
537                         break;
538                 }
539
540                 fd = bpf_map_get_fd_by_id(id);
541                 if (fd < 0) {
542                         if (errno == ENOENT)
543                                 continue;
544                         p_err("can't get map by id (%u): %s",
545                               id, strerror(errno));
546                         break;
547                 }
548
549                 err = bpf_obj_get_info_by_fd(fd, &info, &len);
550                 if (err) {
551                         p_err("can't get map info: %s", strerror(errno));
552                         close(fd);
553                         break;
554                 }
555
556                 if (json_output)
557                         show_map_close_json(fd, &info);
558                 else
559                         show_map_close_plain(fd, &info);
560         }
561         if (json_output)
562                 jsonw_end_array(json_wtr);
563
564         return errno == ENOENT ? 0 : -1;
565 }
566
567 static int do_dump(int argc, char **argv)
568 {
569         void *key, *value, *prev_key;
570         unsigned int num_elems = 0;
571         struct bpf_map_info info = {};
572         __u32 len = sizeof(info);
573         int err;
574         int fd;
575
576         if (argc != 2)
577                 usage();
578
579         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
580         if (fd < 0)
581                 return -1;
582
583         if (map_is_map_of_maps(info.type) || map_is_map_of_progs(info.type)) {
584                 p_err("Dumping maps of maps and program maps not supported");
585                 close(fd);
586                 return -1;
587         }
588
589         key = malloc(info.key_size);
590         value = alloc_value(&info);
591         if (!key || !value) {
592                 p_err("mem alloc failed");
593                 err = -1;
594                 goto exit_free;
595         }
596
597         prev_key = NULL;
598         if (json_output)
599                 jsonw_start_array(json_wtr);
600         while (true) {
601                 err = bpf_map_get_next_key(fd, prev_key, key);
602                 if (err) {
603                         if (errno == ENOENT)
604                                 err = 0;
605                         break;
606                 }
607
608                 if (!bpf_map_lookup_elem(fd, key, value)) {
609                         if (json_output)
610                                 print_entry_json(&info, key, value);
611                         else
612                                 print_entry_plain(&info, key, value);
613                 } else {
614                         if (json_output) {
615                                 jsonw_name(json_wtr, "key");
616                                 print_hex_data_json(key, info.key_size);
617                                 jsonw_name(json_wtr, "value");
618                                 jsonw_start_object(json_wtr);
619                                 jsonw_string_field(json_wtr, "error",
620                                                    "can't lookup element");
621                                 jsonw_end_object(json_wtr);
622                         } else {
623                                 p_info("can't lookup element with key: ");
624                                 fprint_hex(stderr, key, info.key_size, " ");
625                                 fprintf(stderr, "\n");
626                         }
627                 }
628
629                 prev_key = key;
630                 num_elems++;
631         }
632
633         if (json_output)
634                 jsonw_end_array(json_wtr);
635         else
636                 printf("Found %u element%s\n", num_elems,
637                        num_elems != 1 ? "s" : "");
638
639 exit_free:
640         free(key);
641         free(value);
642         close(fd);
643
644         return err;
645 }
646
647 static int do_update(int argc, char **argv)
648 {
649         struct bpf_map_info info = {};
650         __u32 len = sizeof(info);
651         __u32 *value_fd = NULL;
652         __u32 flags = BPF_ANY;
653         void *key, *value;
654         int fd, err;
655
656         if (argc < 2)
657                 usage();
658
659         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
660         if (fd < 0)
661                 return -1;
662
663         key = malloc(info.key_size);
664         value = alloc_value(&info);
665         if (!key || !value) {
666                 p_err("mem alloc failed");
667                 err = -1;
668                 goto exit_free;
669         }
670
671         err = parse_elem(argv, &info, key, value, info.key_size,
672                          info.value_size, &flags, &value_fd);
673         if (err)
674                 goto exit_free;
675
676         err = bpf_map_update_elem(fd, key, value, flags);
677         if (err) {
678                 p_err("update failed: %s", strerror(errno));
679                 goto exit_free;
680         }
681
682 exit_free:
683         if (value_fd)
684                 close(*value_fd);
685         free(key);
686         free(value);
687         close(fd);
688
689         if (!err && json_output)
690                 jsonw_null(json_wtr);
691         return err;
692 }
693
694 static int do_lookup(int argc, char **argv)
695 {
696         struct bpf_map_info info = {};
697         __u32 len = sizeof(info);
698         void *key, *value;
699         int err;
700         int fd;
701
702         if (argc < 2)
703                 usage();
704
705         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
706         if (fd < 0)
707                 return -1;
708
709         key = malloc(info.key_size);
710         value = alloc_value(&info);
711         if (!key || !value) {
712                 p_err("mem alloc failed");
713                 err = -1;
714                 goto exit_free;
715         }
716
717         err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
718         if (err)
719                 goto exit_free;
720
721         err = bpf_map_lookup_elem(fd, key, value);
722         if (!err) {
723                 if (json_output)
724                         print_entry_json(&info, key, value);
725                 else
726                         print_entry_plain(&info, key, value);
727         } else if (errno == ENOENT) {
728                 if (json_output) {
729                         jsonw_null(json_wtr);
730                 } else {
731                         printf("key:\n");
732                         fprint_hex(stdout, key, info.key_size, " ");
733                         printf("\n\nNot found\n");
734                 }
735         } else {
736                 p_err("lookup failed: %s", strerror(errno));
737         }
738
739 exit_free:
740         free(key);
741         free(value);
742         close(fd);
743
744         return err;
745 }
746
747 static int do_getnext(int argc, char **argv)
748 {
749         struct bpf_map_info info = {};
750         __u32 len = sizeof(info);
751         void *key, *nextkey;
752         int err;
753         int fd;
754
755         if (argc < 2)
756                 usage();
757
758         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
759         if (fd < 0)
760                 return -1;
761
762         key = malloc(info.key_size);
763         nextkey = malloc(info.key_size);
764         if (!key || !nextkey) {
765                 p_err("mem alloc failed");
766                 err = -1;
767                 goto exit_free;
768         }
769
770         if (argc) {
771                 err = parse_elem(argv, &info, key, NULL, info.key_size, 0,
772                                  NULL, NULL);
773                 if (err)
774                         goto exit_free;
775         } else {
776                 free(key);
777                 key = NULL;
778         }
779
780         err = bpf_map_get_next_key(fd, key, nextkey);
781         if (err) {
782                 p_err("can't get next key: %s", strerror(errno));
783                 goto exit_free;
784         }
785
786         if (json_output) {
787                 jsonw_start_object(json_wtr);
788                 if (key) {
789                         jsonw_name(json_wtr, "key");
790                         print_hex_data_json(key, info.key_size);
791                 } else {
792                         jsonw_null_field(json_wtr, "key");
793                 }
794                 jsonw_name(json_wtr, "next_key");
795                 print_hex_data_json(nextkey, info.key_size);
796                 jsonw_end_object(json_wtr);
797         } else {
798                 if (key) {
799                         printf("key:\n");
800                         fprint_hex(stdout, key, info.key_size, " ");
801                         printf("\n");
802                 } else {
803                         printf("key: None\n");
804                 }
805                 printf("next key:\n");
806                 fprint_hex(stdout, nextkey, info.key_size, " ");
807                 printf("\n");
808         }
809
810 exit_free:
811         free(nextkey);
812         free(key);
813         close(fd);
814
815         return err;
816 }
817
818 static int do_delete(int argc, char **argv)
819 {
820         struct bpf_map_info info = {};
821         __u32 len = sizeof(info);
822         void *key;
823         int err;
824         int fd;
825
826         if (argc < 2)
827                 usage();
828
829         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
830         if (fd < 0)
831                 return -1;
832
833         key = malloc(info.key_size);
834         if (!key) {
835                 p_err("mem alloc failed");
836                 err = -1;
837                 goto exit_free;
838         }
839
840         err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
841         if (err)
842                 goto exit_free;
843
844         err = bpf_map_delete_elem(fd, key);
845         if (err)
846                 p_err("delete failed: %s", strerror(errno));
847
848 exit_free:
849         free(key);
850         close(fd);
851
852         if (!err && json_output)
853                 jsonw_null(json_wtr);
854         return err;
855 }
856
857 static int do_pin(int argc, char **argv)
858 {
859         int err;
860
861         err = do_pin_any(argc, argv, bpf_map_get_fd_by_id);
862         if (!err && json_output)
863                 jsonw_null(json_wtr);
864         return err;
865 }
866
867 static int do_help(int argc, char **argv)
868 {
869         if (json_output) {
870                 jsonw_null(json_wtr);
871                 return 0;
872         }
873
874         fprintf(stderr,
875                 "Usage: %s %s { show | list }   [MAP]\n"
876                 "       %s %s dump    MAP\n"
877                 "       %s %s update  MAP  key [hex] BYTES value [hex] VALUE [UPDATE_FLAGS]\n"
878                 "       %s %s lookup  MAP  key [hex] BYTES\n"
879                 "       %s %s getnext MAP [key [hex] BYTES]\n"
880                 "       %s %s delete  MAP  key [hex] BYTES\n"
881                 "       %s %s pin     MAP  FILE\n"
882                 "       %s %s help\n"
883                 "\n"
884                 "       MAP := { id MAP_ID | pinned FILE }\n"
885                 "       " HELP_SPEC_PROGRAM "\n"
886                 "       VALUE := { BYTES | MAP | PROG }\n"
887                 "       UPDATE_FLAGS := { any | exist | noexist }\n"
888                 "       " HELP_SPEC_OPTIONS "\n"
889                 "",
890                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
891                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
892                 bin_name, argv[-2], bin_name, argv[-2]);
893
894         return 0;
895 }
896
897 static const struct cmd cmds[] = {
898         { "show",       do_show },
899         { "list",       do_show },
900         { "help",       do_help },
901         { "dump",       do_dump },
902         { "update",     do_update },
903         { "lookup",     do_lookup },
904         { "getnext",    do_getnext },
905         { "delete",     do_delete },
906         { "pin",        do_pin },
907         { 0 }
908 };
909
910 int do_map(int argc, char **argv)
911 {
912         return cmd_select(cmds, argc, argv, do_help);
913 }