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 <linux/kernel.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         [BPF_MAP_TYPE_SOCKHASH]         = "sockhash",
  71 };
  72
  73 static bool map_is_per_cpu(__u32 type)
  74 {
  75         return type == BPF_MAP_TYPE_PERCPU_HASH ||
  76                type == BPF_MAP_TYPE_PERCPU_ARRAY ||
  77                type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
  78 }
  79
  80 static bool map_is_map_of_maps(__u32 type)
  81 {
  82         return type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
  83                type == BPF_MAP_TYPE_HASH_OF_MAPS;
  84 }
  85
  86 static bool map_is_map_of_progs(__u32 type)
  87 {
  88         return type == BPF_MAP_TYPE_PROG_ARRAY;
  89 }
  90
  91 static void *alloc_value(struct bpf_map_info *info)
  92 {
  93         if (map_is_per_cpu(info->type))
  94                 return malloc(round_up(info->value_size, 8) *
  95                               get_possible_cpus());
  96         else
  97                 return malloc(info->value_size);
  98 }
  99
 100 static int map_parse_fd(int *argc, char ***argv)
 101 {
 102         int fd;
 103
 104         if (is_prefix(**argv, "id")) {
 105                 unsigned int id;
 106                 char *endptr;
 107
 108                 NEXT_ARGP();
 109
 110                 id = strtoul(**argv, &endptr, 0);
 111                 if (*endptr) {
 112                         p_err("can't parse %s as ID", **argv);
 113                         return -1;
 114                 }
 115                 NEXT_ARGP();
 116
 117                 fd = bpf_map_get_fd_by_id(id);
 118                 if (fd < 0)
 119                         p_err("get map by id (%u): %s", id, strerror(errno));
 120                 return fd;
 121         } else if (is_prefix(**argv, "pinned")) {
 122                 char *path;
 123
 124                 NEXT_ARGP();
 125
 126                 path = **argv;
 127                 NEXT_ARGP();
 128
 129                 return open_obj_pinned_any(path, BPF_OBJ_MAP);
 130         }
 131
 132         p_err("expected 'id' or 'pinned', got: '%s'?", **argv);
 133         return -1;
 134 }
 135
 136 int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
 137 {
 138         int err;
 139         int fd;
 140
 141         fd = map_parse_fd(argc, argv);
 142         if (fd < 0)
 143                 return -1;
 144
 145         err = bpf_obj_get_info_by_fd(fd, info, info_len);
 146         if (err) {
 147                 p_err("can't get map info: %s", strerror(errno));
 148                 close(fd);
 149                 return err;
 150         }
 151
 152         return fd;
 153 }
 154
 155 static void print_entry_json(struct bpf_map_info *info, unsigned char *key,
 156                              unsigned char *value)
 157 {
 158         jsonw_start_object(json_wtr);
 159
 160         if (!map_is_per_cpu(info->type)) {
 161                 jsonw_name(json_wtr, "key");
 162                 print_hex_data_json(key, info->key_size);
 163                 jsonw_name(json_wtr, "value");
 164                 print_hex_data_json(value, info->value_size);
 165         } else {
 166                 unsigned int i, n, step;
 167
 168                 n = get_possible_cpus();
 169                 step = round_up(info->value_size, 8);
 170
 171                 jsonw_name(json_wtr, "key");
 172                 print_hex_data_json(key, info->key_size);
 173
 174                 jsonw_name(json_wtr, "values");
 175                 jsonw_start_array(json_wtr);
 176                 for (i = 0; i < n; i++) {
 177                         jsonw_start_object(json_wtr);
 178
 179                         jsonw_int_field(json_wtr, "cpu", i);
 180
 181                         jsonw_name(json_wtr, "value");
 182                         print_hex_data_json(value + i * step,
 183                                             info->value_size);
 184
 185                         jsonw_end_object(json_wtr);
 186                 }
 187                 jsonw_end_array(json_wtr);
 188         }
 189
 190         jsonw_end_object(json_wtr);
 191 }
 192
 193 static void print_entry_plain(struct bpf_map_info *info, unsigned char *key,
 194                               unsigned char *value)
 195 {
 196         if (!map_is_per_cpu(info->type)) {
 197                 bool single_line, break_names;
 198
 199                 break_names = info->key_size > 16 || info->value_size > 16;
 200                 single_line = info->key_size + info->value_size <= 24 &&
 201                         !break_names;
 202
 203                 printf("key:%c", break_names ? '\n' : ' ');
 204                 fprint_hex(stdout, key, info->key_size, " ");
 205
 206                 printf(single_line ? "  " : "\n");
 207
 208                 printf("value:%c", break_names ? '\n' : ' ');
 209                 fprint_hex(stdout, value, info->value_size, " ");
 210
 211                 printf("\n");
 212         } else {
 213                 unsigned int i, n, step;
 214
 215                 n = get_possible_cpus();
 216                 step = round_up(info->value_size, 8);
 217
 218                 printf("key:\n");
 219                 fprint_hex(stdout, key, info->key_size, " ");
 220                 printf("\n");
 221                 for (i = 0; i < n; i++) {
 222                         printf("value (CPU %02d):%c",
 223                                i, info->value_size > 16 ? '\n' : ' ');
 224                         fprint_hex(stdout, value + i * step,
 225                                    info->value_size, " ");
 226                         printf("\n");
 227                 }
 228         }
 229 }
 230
 231 static char **parse_bytes(char **argv, const char *name, unsigned char *val,
 232                           unsigned int n)
 233 {
 234         unsigned int i = 0, base = 0;
 235         char *endptr;
 236
 237         if (is_prefix(*argv, "hex")) {
 238                 base = 16;
 239                 argv++;
 240         }
 241
 242         while (i < n && argv[i]) {
 243                 val[i] = strtoul(argv[i], &endptr, base);
 244                 if (*endptr) {
 245                         p_err("error parsing byte: %s", argv[i]);
 246                         return NULL;
 247                 }
 248                 i++;
 249         }
 250
 251         if (i != n) {
 252                 p_err("%s expected %d bytes got %d", name, n, i);
 253                 return NULL;
 254         }
 255
 256         return argv + i;
 257 }
 258
 259 static int parse_elem(char **argv, struct bpf_map_info *info,
 260                       void *key, void *value, __u32 key_size, __u32 value_size,
 261                       __u32 *flags, __u32 **value_fd)
 262 {
 263         if (!*argv) {
 264                 if (!key && !value)
 265                         return 0;
 266                 p_err("did not find %s", key ? "key" : "value");
 267                 return -1;
 268         }
 269
 270         if (is_prefix(*argv, "key")) {
 271                 if (!key) {
 272                         if (key_size)
 273                                 p_err("duplicate key");
 274                         else
 275                                 p_err("unnecessary key");
 276                         return -1;
 277                 }
 278
 279                 argv = parse_bytes(argv + 1, "key", key, key_size);
 280                 if (!argv)
 281                         return -1;
 282
 283                 return parse_elem(argv, info, NULL, value, key_size, value_size,
 284                                   flags, value_fd);
 285         } else if (is_prefix(*argv, "value")) {
 286                 int fd;
 287
 288                 if (!value) {
 289                         if (value_size)
 290                                 p_err("duplicate value");
 291                         else
 292                                 p_err("unnecessary value");
 293                         return -1;
 294                 }
 295
 296                 argv++;
 297
 298                 if (map_is_map_of_maps(info->type)) {
 299                         int argc = 2;
 300
 301                         if (value_size != 4) {
 302                                 p_err("value smaller than 4B for map in map?");
 303                                 return -1;
 304                         }
 305                         if (!argv[0] || !argv[1]) {
 306                                 p_err("not enough value arguments for map in map");
 307                                 return -1;
 308                         }
 309
 310                         fd = map_parse_fd(&argc, &argv);
 311                         if (fd < 0)
 312                                 return -1;
 313
 314                         *value_fd = value;
 315                         **value_fd = fd;
 316                 } else if (map_is_map_of_progs(info->type)) {
 317                         int argc = 2;
 318
 319                         if (value_size != 4) {
 320                                 p_err("value smaller than 4B for map of progs?");
 321                                 return -1;
 322                         }
 323                         if (!argv[0] || !argv[1]) {
 324                                 p_err("not enough value arguments for map of progs");
 325                                 return -1;
 326                         }
 327
 328                         fd = prog_parse_fd(&argc, &argv);
 329                         if (fd < 0)
 330                                 return -1;
 331
 332                         *value_fd = value;
 333                         **value_fd = fd;
 334                 } else {
 335                         argv = parse_bytes(argv, "value", value, value_size);
 336                         if (!argv)
 337                                 return -1;
 338                 }
 339
 340                 return parse_elem(argv, info, key, NULL, key_size, value_size,
 341                                   flags, NULL);
 342         } else if (is_prefix(*argv, "any") || is_prefix(*argv, "noexist") ||
 343                    is_prefix(*argv, "exist")) {
 344                 if (!flags) {
 345                         p_err("flags specified multiple times: %s", *argv);
 346                         return -1;
 347                 }
 348
 349                 if (is_prefix(*argv, "any"))
 350                         *flags = BPF_ANY;
 351                 else if (is_prefix(*argv, "noexist"))
 352                         *flags = BPF_NOEXIST;
 353                 else if (is_prefix(*argv, "exist"))
 354                         *flags = BPF_EXIST;
 355
 356                 return parse_elem(argv + 1, info, key, value, key_size,
 357                                   value_size, NULL, value_fd);
 358         }
 359
 360         p_err("expected key or value, got: %s", *argv);
 361         return -1;
 362 }
 363
 364 static int show_map_close_json(int fd, struct bpf_map_info *info)
 365 {
 366         char *memlock;
 367
 368         memlock = get_fdinfo(fd, "memlock");
 369         close(fd);
 370
 371         jsonw_start_object(json_wtr);
 372
 373         jsonw_uint_field(json_wtr, "id", info->id);
 374         if (info->type < ARRAY_SIZE(map_type_name))
 375                 jsonw_string_field(json_wtr, "type",
 376                                    map_type_name[info->type]);
 377         else
 378                 jsonw_uint_field(json_wtr, "type", info->type);
 379
 380         if (*info->name)
 381                 jsonw_string_field(json_wtr, "name", info->name);
 382
 383         jsonw_name(json_wtr, "flags");
 384         jsonw_printf(json_wtr, "%d", info->map_flags);
 385
 386         print_dev_json(info->ifindex, info->netns_dev, info->netns_ino);
 387
 388         jsonw_uint_field(json_wtr, "bytes_key", info->key_size);
 389         jsonw_uint_field(json_wtr, "bytes_value", info->value_size);
 390         jsonw_uint_field(json_wtr, "max_entries", info->max_entries);
 391
 392         if (memlock)
 393                 jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
 394         free(memlock);
 395
 396         if (!hash_empty(map_table.table)) {
 397                 struct pinned_obj *obj;
 398
 399                 jsonw_name(json_wtr, "pinned");
 400                 jsonw_start_array(json_wtr);
 401                 hash_for_each_possible(map_table.table, obj, hash, info->id) {
 402                         if (obj->id == info->id)
 403                                 jsonw_string(json_wtr, obj->path);
 404                 }
 405                 jsonw_end_array(json_wtr);
 406         }
 407
 408         jsonw_end_object(json_wtr);
 409
 410         return 0;
 411 }
 412
 413 static int show_map_close_plain(int fd, struct bpf_map_info *info)
 414 {
 415         char *memlock;
 416
 417         memlock = get_fdinfo(fd, "memlock");
 418         close(fd);
 419
 420         printf("%u: ", info->id);
 421         if (info->type < ARRAY_SIZE(map_type_name))
 422                 printf("%s  ", map_type_name[info->type]);
 423         else
 424                 printf("type %u  ", info->type);
 425
 426         if (*info->name)
 427                 printf("name %s  ", info->name);
 428
 429         printf("flags 0x%x", info->map_flags);
 430         print_dev_plain(info->ifindex, info->netns_dev, info->netns_ino);
 431         printf("\n");
 432         printf("\tkey %uB  value %uB  max_entries %u",
 433                info->key_size, info->value_size, info->max_entries);
 434
 435         if (memlock)
 436                 printf("  memlock %sB", memlock);
 437         free(memlock);
 438
 439         printf("\n");
 440         if (!hash_empty(map_table.table)) {
 441                 struct pinned_obj *obj;
 442
 443                 hash_for_each_possible(map_table.table, obj, hash, info->id) {
 444                         if (obj->id == info->id)
 445                                 printf("\tpinned %s\n", obj->path);
 446                 }
 447         }
 448         return 0;
 449 }
 450
 451 static int do_show(int argc, char **argv)
 452 {
 453         struct bpf_map_info info = {};
 454         __u32 len = sizeof(info);
 455         __u32 id = 0;
 456         int err;
 457         int fd;
 458
 459         if (show_pinned)
 460                 build_pinned_obj_table(&map_table, BPF_OBJ_MAP);
 461
 462         if (argc == 2) {
 463                 fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 464                 if (fd < 0)
 465                         return -1;
 466
 467                 if (json_output)
 468                         return show_map_close_json(fd, &info);
 469                 else
 470                         return show_map_close_plain(fd, &info);
 471         }
 472
 473         if (argc)
 474                 return BAD_ARG();
 475
 476         if (json_output)
 477                 jsonw_start_array(json_wtr);
 478         while (true) {
 479                 err = bpf_map_get_next_id(id, &id);
 480                 if (err) {
 481                         if (errno == ENOENT)
 482                                 break;
 483                         p_err("can't get next map: %s%s", strerror(errno),
 484                               errno == EINVAL ? " -- kernel too old?" : "");
 485                         break;
 486                 }
 487
 488                 fd = bpf_map_get_fd_by_id(id);
 489                 if (fd < 0) {
 490                         if (errno == ENOENT)
 491                                 continue;
 492                         p_err("can't get map by id (%u): %s",
 493                               id, strerror(errno));
 494                         break;
 495                 }
 496
 497                 err = bpf_obj_get_info_by_fd(fd, &info, &len);
 498                 if (err) {
 499                         p_err("can't get map info: %s", strerror(errno));
 500                         close(fd);
 501                         break;
 502                 }
 503
 504                 if (json_output)
 505                         show_map_close_json(fd, &info);
 506                 else
 507                         show_map_close_plain(fd, &info);
 508         }
 509         if (json_output)
 510                 jsonw_end_array(json_wtr);
 511
 512         return errno == ENOENT ? 0 : -1;
 513 }
 514
 515 static int do_dump(int argc, char **argv)
 516 {
 517         void *key, *value, *prev_key;
 518         unsigned int num_elems = 0;
 519         struct bpf_map_info info = {};
 520         __u32 len = sizeof(info);
 521         int err;
 522         int fd;
 523
 524         if (argc != 2)
 525                 usage();
 526
 527         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 528         if (fd < 0)
 529                 return -1;
 530
 531         if (map_is_map_of_maps(info.type) || map_is_map_of_progs(info.type)) {
 532                 p_err("Dumping maps of maps and program maps not supported");
 533                 close(fd);
 534                 return -1;
 535         }
 536
 537         key = malloc(info.key_size);
 538         value = alloc_value(&info);
 539         if (!key || !value) {
 540                 p_err("mem alloc failed");
 541                 err = -1;
 542                 goto exit_free;
 543         }
 544
 545         prev_key = NULL;
 546         if (json_output)
 547                 jsonw_start_array(json_wtr);
 548         while (true) {
 549                 err = bpf_map_get_next_key(fd, prev_key, key);
 550                 if (err) {
 551                         if (errno == ENOENT)
 552                                 err = 0;
 553                         break;
 554                 }
 555
 556                 if (!bpf_map_lookup_elem(fd, key, value)) {
 557                         if (json_output)
 558                                 print_entry_json(&info, key, value);
 559                         else
 560                                 print_entry_plain(&info, key, value);
 561                 } else {
 562                         if (json_output) {
 563                                 jsonw_name(json_wtr, "key");
 564                                 print_hex_data_json(key, info.key_size);
 565                                 jsonw_name(json_wtr, "value");
 566                                 jsonw_start_object(json_wtr);
 567                                 jsonw_string_field(json_wtr, "error",
 568                                                    "can't lookup element");
 569                                 jsonw_end_object(json_wtr);
 570                         } else {
 571                                 p_info("can't lookup element with key: ");
 572                                 fprint_hex(stderr, key, info.key_size, " ");
 573                                 fprintf(stderr, "\n");
 574                         }
 575                 }
 576
 577                 prev_key = key;
 578                 num_elems++;
 579         }
 580
 581         if (json_output)
 582                 jsonw_end_array(json_wtr);
 583         else
 584                 printf("Found %u element%s\n", num_elems,
 585                        num_elems != 1 ? "s" : "");
 586
 587 exit_free:
 588         free(key);
 589         free(value);
 590         close(fd);
 591
 592         return err;
 593 }
 594
 595 static int do_update(int argc, char **argv)
 596 {
 597         struct bpf_map_info info = {};
 598         __u32 len = sizeof(info);
 599         __u32 *value_fd = NULL;
 600         __u32 flags = BPF_ANY;
 601         void *key, *value;
 602         int fd, err;
 603
 604         if (argc < 2)
 605                 usage();
 606
 607         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 608         if (fd < 0)
 609                 return -1;
 610
 611         key = malloc(info.key_size);
 612         value = alloc_value(&info);
 613         if (!key || !value) {
 614                 p_err("mem alloc failed");
 615                 err = -1;
 616                 goto exit_free;
 617         }
 618
 619         err = parse_elem(argv, &info, key, value, info.key_size,
 620                          info.value_size, &flags, &value_fd);
 621         if (err)
 622                 goto exit_free;
 623
 624         err = bpf_map_update_elem(fd, key, value, flags);
 625         if (err) {
 626                 p_err("update failed: %s", strerror(errno));
 627                 goto exit_free;
 628         }
 629
 630 exit_free:
 631         if (value_fd)
 632                 close(*value_fd);
 633         free(key);
 634         free(value);
 635         close(fd);
 636
 637         if (!err && json_output)
 638                 jsonw_null(json_wtr);
 639         return err;
 640 }
 641
 642 static int do_lookup(int argc, char **argv)
 643 {
 644         struct bpf_map_info info = {};
 645         __u32 len = sizeof(info);
 646         void *key, *value;
 647         int err;
 648         int fd;
 649
 650         if (argc < 2)
 651                 usage();
 652
 653         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 654         if (fd < 0)
 655                 return -1;
 656
 657         key = malloc(info.key_size);
 658         value = alloc_value(&info);
 659         if (!key || !value) {
 660                 p_err("mem alloc failed");
 661                 err = -1;
 662                 goto exit_free;
 663         }
 664
 665         err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
 666         if (err)
 667                 goto exit_free;
 668
 669         err = bpf_map_lookup_elem(fd, key, value);
 670         if (!err) {
 671                 if (json_output)
 672                         print_entry_json(&info, key, value);
 673                 else
 674                         print_entry_plain(&info, key, value);
 675         } else if (errno == ENOENT) {
 676                 if (json_output) {
 677                         jsonw_null(json_wtr);
 678                 } else {
 679                         printf("key:\n");
 680                         fprint_hex(stdout, key, info.key_size, " ");
 681                         printf("\n\nNot found\n");
 682                 }
 683         } else {
 684                 p_err("lookup failed: %s", strerror(errno));
 685         }
 686
 687 exit_free:
 688         free(key);
 689         free(value);
 690         close(fd);
 691
 692         return err;
 693 }
 694
 695 static int do_getnext(int argc, char **argv)
 696 {
 697         struct bpf_map_info info = {};
 698         __u32 len = sizeof(info);
 699         void *key, *nextkey;
 700         int err;
 701         int fd;
 702
 703         if (argc < 2)
 704                 usage();
 705
 706         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 707         if (fd < 0)
 708                 return -1;
 709
 710         key = malloc(info.key_size);
 711         nextkey = malloc(info.key_size);
 712         if (!key || !nextkey) {
 713                 p_err("mem alloc failed");
 714                 err = -1;
 715                 goto exit_free;
 716         }
 717
 718         if (argc) {
 719                 err = parse_elem(argv, &info, key, NULL, info.key_size, 0,
 720                                  NULL, NULL);
 721                 if (err)
 722                         goto exit_free;
 723         } else {
 724                 free(key);
 725                 key = NULL;
 726         }
 727
 728         err = bpf_map_get_next_key(fd, key, nextkey);
 729         if (err) {
 730                 p_err("can't get next key: %s", strerror(errno));
 731                 goto exit_free;
 732         }
 733
 734         if (json_output) {
 735                 jsonw_start_object(json_wtr);
 736                 if (key) {
 737                         jsonw_name(json_wtr, "key");
 738                         print_hex_data_json(key, info.key_size);
 739                 } else {
 740                         jsonw_null_field(json_wtr, "key");
 741                 }
 742                 jsonw_name(json_wtr, "next_key");
 743                 print_hex_data_json(nextkey, info.key_size);
 744                 jsonw_end_object(json_wtr);
 745         } else {
 746                 if (key) {
 747                         printf("key:\n");
 748                         fprint_hex(stdout, key, info.key_size, " ");
 749                         printf("\n");
 750                 } else {
 751                         printf("key: None\n");
 752                 }
 753                 printf("next key:\n");
 754                 fprint_hex(stdout, nextkey, info.key_size, " ");
 755                 printf("\n");
 756         }
 757
 758 exit_free:
 759         free(nextkey);
 760         free(key);
 761         close(fd);
 762
 763         return err;
 764 }
 765
 766 static int do_delete(int argc, char **argv)
 767 {
 768         struct bpf_map_info info = {};
 769         __u32 len = sizeof(info);
 770         void *key;
 771         int err;
 772         int fd;
 773
 774         if (argc < 2)
 775                 usage();
 776
 777         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 778         if (fd < 0)
 779                 return -1;
 780
 781         key = malloc(info.key_size);
 782         if (!key) {
 783                 p_err("mem alloc failed");
 784                 err = -1;
 785                 goto exit_free;
 786         }
 787
 788         err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
 789         if (err)
 790                 goto exit_free;
 791
 792         err = bpf_map_delete_elem(fd, key);
 793         if (err)
 794                 p_err("delete failed: %s", strerror(errno));
 795
 796 exit_free:
 797         free(key);
 798         close(fd);
 799
 800         if (!err && json_output)
 801                 jsonw_null(json_wtr);
 802         return err;
 803 }
 804
 805 static int do_pin(int argc, char **argv)
 806 {
 807         int err;
 808
 809         err = do_pin_any(argc, argv, bpf_map_get_fd_by_id);
 810         if (!err && json_output)
 811                 jsonw_null(json_wtr);
 812         return err;
 813 }
 814
 815 static int do_help(int argc, char **argv)
 816 {
 817         if (json_output) {
 818                 jsonw_null(json_wtr);
 819                 return 0;
 820         }
 821
 822         fprintf(stderr,
 823                 "Usage: %s %s { show | list }   [MAP]\n"
 824                 "       %s %s dump       MAP\n"
 825                 "       %s %s update     MAP  key DATA value VALUE [UPDATE_FLAGS]\n"
 826                 "       %s %s lookup     MAP  key DATA\n"
 827                 "       %s %s getnext    MAP [key DATA]\n"
 828                 "       %s %s delete     MAP  key DATA\n"
 829                 "       %s %s pin        MAP  FILE\n"
 830                 "       %s %s event_pipe MAP [cpu N index M]\n"
 831                 "       %s %s help\n"
 832                 "\n"
 833                 "       MAP := { id MAP_ID | pinned FILE }\n"
 834                 "       DATA := { [hex] BYTES }\n"
 835                 "       " HELP_SPEC_PROGRAM "\n"
 836                 "       VALUE := { DATA | MAP | PROG }\n"
 837                 "       UPDATE_FLAGS := { any | exist | noexist }\n"
 838                 "       " HELP_SPEC_OPTIONS "\n"
 839                 "",
 840                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
 841                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
 842                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]);
 843
 844         return 0;
 845 }
 846
 847 static const struct cmd cmds[] = {
 848         { "show",       do_show },
 849         { "list",       do_show },
 850         { "help",       do_help },
 851         { "dump",       do_dump },
 852         { "update",     do_update },
 853         { "lookup",     do_lookup },
 854         { "getnext",    do_getnext },
 855         { "delete",     do_delete },
 856         { "pin",        do_pin },
 857         { "event_pipe", do_event_pipe },
 858         { 0 }
 859 };
 860
 861 int do_map(int argc, char **argv)
 862 {
 863         return cmd_select(cmds, argc, argv, do_help);
 864 }