tools/bpf/bpftool/map.c

   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 }