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 #include <assert.h>
  35 #include <errno.h>
  36 #include <fcntl.h>
  37 #include <linux/err.h>
  38 #include <stdbool.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <unistd.h>
  43 #include <sys/types.h>
  44 #include <sys/stat.h>
  45
  46 #include <bpf.h>
  47
  48 #include "btf.h"
  49 #include "json_writer.h"
  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         [BPF_MAP_TYPE_CGROUP_STORAGE]   = "cgroup_storage",
  72 };
  73
  74 static bool map_is_per_cpu(__u32 type)
  75 {
  76         return type == BPF_MAP_TYPE_PERCPU_HASH ||
  77                type == BPF_MAP_TYPE_PERCPU_ARRAY ||
  78                type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
  79 }
  80
  81 static bool map_is_map_of_maps(__u32 type)
  82 {
  83         return type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
  84                type == BPF_MAP_TYPE_HASH_OF_MAPS;
  85 }
  86
  87 static bool map_is_map_of_progs(__u32 type)
  88 {
  89         return type == BPF_MAP_TYPE_PROG_ARRAY;
  90 }
  91
  92 static void *alloc_value(struct bpf_map_info *info)
  93 {
  94         if (map_is_per_cpu(info->type))
  95                 return malloc(info->value_size * get_possible_cpus());
  96         else
  97                 return malloc(info->value_size);
  98 }
  99
 100 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 int do_dump_btf(const struct btf_dumper *d,
 156                        struct bpf_map_info *map_info, void *key,
 157                        void *value)
 158 {
 159         int ret;
 160
 161         /* start of key-value pair */
 162         jsonw_start_object(d->jw);
 163
 164         jsonw_name(d->jw, "key");
 165
 166         ret = btf_dumper_type(d, map_info->btf_key_type_id, key);
 167         if (ret)
 168                 goto err_end_obj;
 169
 170         jsonw_name(d->jw, "value");
 171
 172         ret = btf_dumper_type(d, map_info->btf_value_type_id, value);
 173
 174 err_end_obj:
 175         /* end of key-value pair */
 176         jsonw_end_object(d->jw);
 177
 178         return ret;
 179 }
 180
 181 static int get_btf(struct bpf_map_info *map_info, struct btf **btf)
 182 {
 183         struct bpf_btf_info btf_info = { 0 };
 184         __u32 len = sizeof(btf_info);
 185         __u32 last_size;
 186         int btf_fd;
 187         void *ptr;
 188         int err;
 189
 190         err = 0;
 191         *btf = NULL;
 192         btf_fd = bpf_btf_get_fd_by_id(map_info->btf_id);
 193         if (btf_fd < 0)
 194                 return 0;
 195
 196         /* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so
 197          * let's start with a sane default - 4KiB here - and resize it only if
 198          * bpf_obj_get_info_by_fd() needs a bigger buffer.
 199          */
 200         btf_info.btf_size = 4096;
 201         last_size = btf_info.btf_size;
 202         ptr = malloc(last_size);
 203         if (!ptr) {
 204                 err = -ENOMEM;
 205                 goto exit_free;
 206         }
 207
 208         bzero(ptr, last_size);
 209         btf_info.btf = ptr_to_u64(ptr);
 210         err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
 211
 212         if (!err && btf_info.btf_size > last_size) {
 213                 void *temp_ptr;
 214
 215                 last_size = btf_info.btf_size;
 216                 temp_ptr = realloc(ptr, last_size);
 217                 if (!temp_ptr) {
 218                         err = -ENOMEM;
 219                         goto exit_free;
 220                 }
 221                 ptr = temp_ptr;
 222                 bzero(ptr, last_size);
 223                 btf_info.btf = ptr_to_u64(ptr);
 224                 err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
 225         }
 226
 227         if (err || btf_info.btf_size > last_size) {
 228                 err = errno;
 229                 goto exit_free;
 230         }
 231
 232         *btf = btf__new((__u8 *)btf_info.btf, btf_info.btf_size, NULL);
 233         if (IS_ERR(*btf)) {
 234                 err = PTR_ERR(*btf);
 235                 *btf = NULL;
 236         }
 237
 238 exit_free:
 239         close(btf_fd);
 240         free(ptr);
 241
 242         return err;
 243 }
 244
 245 static json_writer_t *get_btf_writer(void)
 246 {
 247         json_writer_t *jw = jsonw_new(stdout);
 248
 249         if (!jw)
 250                 return NULL;
 251         jsonw_pretty(jw, true);
 252
 253         return jw;
 254 }
 255
 256 static void print_entry_json(struct bpf_map_info *info, unsigned char *key,
 257                              unsigned char *value, struct btf *btf)
 258 {
 259         jsonw_start_object(json_wtr);
 260
 261         if (!map_is_per_cpu(info->type)) {
 262                 jsonw_name(json_wtr, "key");
 263                 print_hex_data_json(key, info->key_size);
 264                 jsonw_name(json_wtr, "value");
 265                 print_hex_data_json(value, info->value_size);
 266                 if (btf) {
 267                         struct btf_dumper d = {
 268                                 .btf = btf,
 269                                 .jw = json_wtr,
 270                                 .is_plain_text = false,
 271                         };
 272
 273                         jsonw_name(json_wtr, "formatted");
 274                         do_dump_btf(&d, info, key, value);
 275                 }
 276         } else {
 277                 unsigned int i, n;
 278
 279                 n = get_possible_cpus();
 280
 281                 jsonw_name(json_wtr, "key");
 282                 print_hex_data_json(key, info->key_size);
 283
 284                 jsonw_name(json_wtr, "values");
 285                 jsonw_start_array(json_wtr);
 286                 for (i = 0; i < n; i++) {
 287                         jsonw_start_object(json_wtr);
 288
 289                         jsonw_int_field(json_wtr, "cpu", i);
 290
 291                         jsonw_name(json_wtr, "value");
 292                         print_hex_data_json(value + i * info->value_size,
 293                                             info->value_size);
 294
 295                         jsonw_end_object(json_wtr);
 296                 }
 297                 jsonw_end_array(json_wtr);
 298         }
 299
 300         jsonw_end_object(json_wtr);
 301 }
 302
 303 static void print_entry_plain(struct bpf_map_info *info, unsigned char *key,
 304                               unsigned char *value)
 305 {
 306         if (!map_is_per_cpu(info->type)) {
 307                 bool single_line, break_names;
 308
 309                 break_names = info->key_size > 16 || info->value_size > 16;
 310                 single_line = info->key_size + info->value_size <= 24 &&
 311                         !break_names;
 312
 313                 printf("key:%c", break_names ? '\n' : ' ');
 314                 fprint_hex(stdout, key, info->key_size, " ");
 315
 316                 printf(single_line ? "  " : "\n");
 317
 318                 printf("value:%c", break_names ? '\n' : ' ');
 319                 fprint_hex(stdout, value, info->value_size, " ");
 320
 321                 printf("\n");
 322         } else {
 323                 unsigned int i, n;
 324
 325                 n = get_possible_cpus();
 326
 327                 printf("key:\n");
 328                 fprint_hex(stdout, key, info->key_size, " ");
 329                 printf("\n");
 330                 for (i = 0; i < n; i++) {
 331                         printf("value (CPU %02d):%c",
 332                                i, info->value_size > 16 ? '\n' : ' ');
 333                         fprint_hex(stdout, value + i * info->value_size,
 334                                    info->value_size, " ");
 335                         printf("\n");
 336                 }
 337         }
 338 }
 339
 340 static char **parse_bytes(char **argv, const char *name, unsigned char *val,
 341                           unsigned int n)
 342 {
 343         unsigned int i = 0, base = 0;
 344         char *endptr;
 345
 346         if (is_prefix(*argv, "hex")) {
 347                 base = 16;
 348                 argv++;
 349         }
 350
 351         while (i < n && argv[i]) {
 352                 val[i] = strtoul(argv[i], &endptr, base);
 353                 if (*endptr) {
 354                         p_err("error parsing byte: %s", argv[i]);
 355                         return NULL;
 356                 }
 357                 i++;
 358         }
 359
 360         if (i != n) {
 361                 p_err("%s expected %d bytes got %d", name, n, i);
 362                 return NULL;
 363         }
 364
 365         return argv + i;
 366 }
 367
 368 static int parse_elem(char **argv, struct bpf_map_info *info,
 369                       void *key, void *value, __u32 key_size, __u32 value_size,
 370                       __u32 *flags, __u32 **value_fd)
 371 {
 372         if (!*argv) {
 373                 if (!key && !value)
 374                         return 0;
 375                 p_err("did not find %s", key ? "key" : "value");
 376                 return -1;
 377         }
 378
 379         if (is_prefix(*argv, "key")) {
 380                 if (!key) {
 381                         if (key_size)
 382                                 p_err("duplicate key");
 383                         else
 384                                 p_err("unnecessary key");
 385                         return -1;
 386                 }
 387
 388                 argv = parse_bytes(argv + 1, "key", key, key_size);
 389                 if (!argv)
 390                         return -1;
 391
 392                 return parse_elem(argv, info, NULL, value, key_size, value_size,
 393                                   flags, value_fd);
 394         } else if (is_prefix(*argv, "value")) {
 395                 int fd;
 396
 397                 if (!value) {
 398                         if (value_size)
 399                                 p_err("duplicate value");
 400                         else
 401                                 p_err("unnecessary value");
 402                         return -1;
 403                 }
 404
 405                 argv++;
 406
 407                 if (map_is_map_of_maps(info->type)) {
 408                         int argc = 2;
 409
 410                         if (value_size != 4) {
 411                                 p_err("value smaller than 4B for map in map?");
 412                                 return -1;
 413                         }
 414                         if (!argv[0] || !argv[1]) {
 415                                 p_err("not enough value arguments for map in map");
 416                                 return -1;
 417                         }
 418
 419                         fd = map_parse_fd(&argc, &argv);
 420                         if (fd < 0)
 421                                 return -1;
 422
 423                         *value_fd = value;
 424                         **value_fd = fd;
 425                 } else if (map_is_map_of_progs(info->type)) {
 426                         int argc = 2;
 427
 428                         if (value_size != 4) {
 429                                 p_err("value smaller than 4B for map of progs?");
 430                                 return -1;
 431                         }
 432                         if (!argv[0] || !argv[1]) {
 433                                 p_err("not enough value arguments for map of progs");
 434                                 return -1;
 435                         }
 436
 437                         fd = prog_parse_fd(&argc, &argv);
 438                         if (fd < 0)
 439                                 return -1;
 440
 441                         *value_fd = value;
 442                         **value_fd = fd;
 443                 } else {
 444                         argv = parse_bytes(argv, "value", value, value_size);
 445                         if (!argv)
 446                                 return -1;
 447                 }
 448
 449                 return parse_elem(argv, info, key, NULL, key_size, value_size,
 450                                   flags, NULL);
 451         } else if (is_prefix(*argv, "any") || is_prefix(*argv, "noexist") ||
 452                    is_prefix(*argv, "exist")) {
 453                 if (!flags) {
 454                         p_err("flags specified multiple times: %s", *argv);
 455                         return -1;
 456                 }
 457
 458                 if (is_prefix(*argv, "any"))
 459                         *flags = BPF_ANY;
 460                 else if (is_prefix(*argv, "noexist"))
 461                         *flags = BPF_NOEXIST;
 462                 else if (is_prefix(*argv, "exist"))
 463                         *flags = BPF_EXIST;
 464
 465                 return parse_elem(argv + 1, info, key, value, key_size,
 466                                   value_size, NULL, value_fd);
 467         }
 468
 469         p_err("expected key or value, got: %s", *argv);
 470         return -1;
 471 }
 472
 473 static int show_map_close_json(int fd, struct bpf_map_info *info)
 474 {
 475         char *memlock;
 476
 477         memlock = get_fdinfo(fd, "memlock");
 478         close(fd);
 479
 480         jsonw_start_object(json_wtr);
 481
 482         jsonw_uint_field(json_wtr, "id", info->id);
 483         if (info->type < ARRAY_SIZE(map_type_name))
 484                 jsonw_string_field(json_wtr, "type",
 485                                    map_type_name[info->type]);
 486         else
 487                 jsonw_uint_field(json_wtr, "type", info->type);
 488
 489         if (*info->name)
 490                 jsonw_string_field(json_wtr, "name", info->name);
 491
 492         jsonw_name(json_wtr, "flags");
 493         jsonw_printf(json_wtr, "%d", info->map_flags);
 494
 495         print_dev_json(info->ifindex, info->netns_dev, info->netns_ino);
 496
 497         jsonw_uint_field(json_wtr, "bytes_key", info->key_size);
 498         jsonw_uint_field(json_wtr, "bytes_value", info->value_size);
 499         jsonw_uint_field(json_wtr, "max_entries", info->max_entries);
 500
 501         if (memlock)
 502                 jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
 503         free(memlock);
 504
 505         if (!hash_empty(map_table.table)) {
 506                 struct pinned_obj *obj;
 507
 508                 jsonw_name(json_wtr, "pinned");
 509                 jsonw_start_array(json_wtr);
 510                 hash_for_each_possible(map_table.table, obj, hash, info->id) {
 511                         if (obj->id == info->id)
 512                                 jsonw_string(json_wtr, obj->path);
 513                 }
 514                 jsonw_end_array(json_wtr);
 515         }
 516
 517         jsonw_end_object(json_wtr);
 518
 519         return 0;
 520 }
 521
 522 static int show_map_close_plain(int fd, struct bpf_map_info *info)
 523 {
 524         char *memlock;
 525
 526         memlock = get_fdinfo(fd, "memlock");
 527         close(fd);
 528
 529         printf("%u: ", info->id);
 530         if (info->type < ARRAY_SIZE(map_type_name))
 531                 printf("%s  ", map_type_name[info->type]);
 532         else
 533                 printf("type %u  ", info->type);
 534
 535         if (*info->name)
 536                 printf("name %s  ", info->name);
 537
 538         printf("flags 0x%x", info->map_flags);
 539         print_dev_plain(info->ifindex, info->netns_dev, info->netns_ino);
 540         printf("\n");
 541         printf("\tkey %uB  value %uB  max_entries %u",
 542                info->key_size, info->value_size, info->max_entries);
 543
 544         if (memlock)
 545                 printf("  memlock %sB", memlock);
 546         free(memlock);
 547
 548         printf("\n");
 549         if (!hash_empty(map_table.table)) {
 550                 struct pinned_obj *obj;
 551
 552                 hash_for_each_possible(map_table.table, obj, hash, info->id) {
 553                         if (obj->id == info->id)
 554                                 printf("\tpinned %s\n", obj->path);
 555                 }
 556         }
 557         return 0;
 558 }
 559
 560 static int do_show(int argc, char **argv)
 561 {
 562         struct bpf_map_info info = {};
 563         __u32 len = sizeof(info);
 564         __u32 id = 0;
 565         int err;
 566         int fd;
 567
 568         if (show_pinned)
 569                 build_pinned_obj_table(&map_table, BPF_OBJ_MAP);
 570
 571         if (argc == 2) {
 572                 fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 573                 if (fd < 0)
 574                         return -1;
 575
 576                 if (json_output)
 577                         return show_map_close_json(fd, &info);
 578                 else
 579                         return show_map_close_plain(fd, &info);
 580         }
 581
 582         if (argc)
 583                 return BAD_ARG();
 584
 585         if (json_output)
 586                 jsonw_start_array(json_wtr);
 587         while (true) {
 588                 err = bpf_map_get_next_id(id, &id);
 589                 if (err) {
 590                         if (errno == ENOENT)
 591                                 break;
 592                         p_err("can't get next map: %s%s", strerror(errno),
 593                               errno == EINVAL ? " -- kernel too old?" : "");
 594                         break;
 595                 }
 596
 597                 fd = bpf_map_get_fd_by_id(id);
 598                 if (fd < 0) {
 599                         if (errno == ENOENT)
 600                                 continue;
 601                         p_err("can't get map by id (%u): %s",
 602                               id, strerror(errno));
 603                         break;
 604                 }
 605
 606                 err = bpf_obj_get_info_by_fd(fd, &info, &len);
 607                 if (err) {
 608                         p_err("can't get map info: %s", strerror(errno));
 609                         close(fd);
 610                         break;
 611                 }
 612
 613                 if (json_output)
 614                         show_map_close_json(fd, &info);
 615                 else
 616                         show_map_close_plain(fd, &info);
 617         }
 618         if (json_output)
 619                 jsonw_end_array(json_wtr);
 620
 621         return errno == ENOENT ? 0 : -1;
 622 }
 623
 624 static int do_dump(int argc, char **argv)
 625 {
 626         struct bpf_map_info info = {};
 627         void *key, *value, *prev_key;
 628         unsigned int num_elems = 0;
 629         __u32 len = sizeof(info);
 630         json_writer_t *btf_wtr;
 631         struct btf *btf = NULL;
 632         int err;
 633         int fd;
 634
 635         if (argc != 2)
 636                 usage();
 637
 638         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 639         if (fd < 0)
 640                 return -1;
 641
 642         if (map_is_map_of_maps(info.type) || map_is_map_of_progs(info.type)) {
 643                 p_err("Dumping maps of maps and program maps not supported");
 644                 close(fd);
 645                 return -1;
 646         }
 647
 648         key = malloc(info.key_size);
 649         value = alloc_value(&info);
 650         if (!key || !value) {
 651                 p_err("mem alloc failed");
 652                 err = -1;
 653                 goto exit_free;
 654         }
 655
 656         prev_key = NULL;
 657
 658         err = get_btf(&info, &btf);
 659         if (err) {
 660                 p_err("failed to get btf");
 661                 goto exit_free;
 662         }
 663
 664         if (json_output)
 665                 jsonw_start_array(json_wtr);
 666         else
 667                 if (btf) {
 668                         btf_wtr = get_btf_writer();
 669                         if (!btf_wtr) {
 670                                 p_info("failed to create json writer for btf. falling back to plain output");
 671                                 btf__free(btf);
 672                                 btf = NULL;
 673                         } else {
 674                                 jsonw_start_array(btf_wtr);
 675                         }
 676                 }
 677
 678         while (true) {
 679                 err = bpf_map_get_next_key(fd, prev_key, key);
 680                 if (err) {
 681                         if (errno == ENOENT)
 682                                 err = 0;
 683                         break;
 684                 }
 685
 686                 if (!bpf_map_lookup_elem(fd, key, value)) {
 687                         if (json_output)
 688                                 print_entry_json(&info, key, value, btf);
 689                         else
 690                                 if (btf) {
 691                                         struct btf_dumper d = {
 692                                                 .btf = btf,
 693                                                 .jw = btf_wtr,
 694                                                 .is_plain_text = true,
 695                                         };
 696
 697                                         do_dump_btf(&d, &info, key, value);
 698                                 } else {
 699                                         print_entry_plain(&info, key, value);
 700                                 }
 701                 } else {
 702                         if (json_output) {
 703                                 jsonw_name(json_wtr, "key");
 704                                 print_hex_data_json(key, info.key_size);
 705                                 jsonw_name(json_wtr, "value");
 706                                 jsonw_start_object(json_wtr);
 707                                 jsonw_string_field(json_wtr, "error",
 708                                                    "can't lookup element");
 709                                 jsonw_end_object(json_wtr);
 710                         } else {
 711                                 p_info("can't lookup element with key: ");
 712                                 fprint_hex(stderr, key, info.key_size, " ");
 713                                 fprintf(stderr, "\n");
 714                         }
 715                 }
 716
 717                 prev_key = key;
 718                 num_elems++;
 719         }
 720
 721         if (json_output)
 722                 jsonw_end_array(json_wtr);
 723         else if (btf) {
 724                 jsonw_end_array(btf_wtr);
 725                 jsonw_destroy(&btf_wtr);
 726         } else {
 727                 printf("Found %u element%s\n", num_elems,
 728                        num_elems != 1 ? "s" : "");
 729         }
 730
 731 exit_free:
 732         free(key);
 733         free(value);
 734         close(fd);
 735         btf__free(btf);
 736
 737         return err;
 738 }
 739
 740 static int do_update(int argc, char **argv)
 741 {
 742         struct bpf_map_info info = {};
 743         __u32 len = sizeof(info);
 744         __u32 *value_fd = NULL;
 745         __u32 flags = BPF_ANY;
 746         void *key, *value;
 747         int fd, err;
 748
 749         if (argc < 2)
 750                 usage();
 751
 752         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 753         if (fd < 0)
 754                 return -1;
 755
 756         key = malloc(info.key_size);
 757         value = alloc_value(&info);
 758         if (!key || !value) {
 759                 p_err("mem alloc failed");
 760                 err = -1;
 761                 goto exit_free;
 762         }
 763
 764         err = parse_elem(argv, &info, key, value, info.key_size,
 765                          info.value_size, &flags, &value_fd);
 766         if (err)
 767                 goto exit_free;
 768
 769         err = bpf_map_update_elem(fd, key, value, flags);
 770         if (err) {
 771                 p_err("update failed: %s", strerror(errno));
 772                 goto exit_free;
 773         }
 774
 775 exit_free:
 776         if (value_fd)
 777                 close(*value_fd);
 778         free(key);
 779         free(value);
 780         close(fd);
 781
 782         if (!err && json_output)
 783                 jsonw_null(json_wtr);
 784         return err;
 785 }
 786
 787 static int do_lookup(int argc, char **argv)
 788 {
 789         struct bpf_map_info info = {};
 790         __u32 len = sizeof(info);
 791         json_writer_t *btf_wtr;
 792         struct btf *btf = NULL;
 793         void *key, *value;
 794         int err;
 795         int fd;
 796
 797         if (argc < 2)
 798                 usage();
 799
 800         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 801         if (fd < 0)
 802                 return -1;
 803
 804         key = malloc(info.key_size);
 805         value = alloc_value(&info);
 806         if (!key || !value) {
 807                 p_err("mem alloc failed");
 808                 err = -1;
 809                 goto exit_free;
 810         }
 811
 812         err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
 813         if (err)
 814                 goto exit_free;
 815
 816         err = bpf_map_lookup_elem(fd, key, value);
 817         if (err) {
 818                 if (errno == ENOENT) {
 819                         if (json_output) {
 820                                 jsonw_null(json_wtr);
 821                         } else {
 822                                 printf("key:\n");
 823                                 fprint_hex(stdout, key, info.key_size, " ");
 824                                 printf("\n\nNot found\n");
 825                         }
 826                 } else {
 827                         p_err("lookup failed: %s", strerror(errno));
 828                 }
 829
 830                 goto exit_free;
 831         }
 832
 833         /* here means bpf_map_lookup_elem() succeeded */
 834         err = get_btf(&info, &btf);
 835         if (err) {
 836                 p_err("failed to get btf");
 837                 goto exit_free;
 838         }
 839
 840         if (json_output) {
 841                 print_entry_json(&info, key, value, btf);
 842         } else if (btf) {
 843                 /* if here json_wtr wouldn't have been initialised,
 844                  * so let's create separate writer for btf
 845                  */
 846                 btf_wtr = get_btf_writer();
 847                 if (!btf_wtr) {
 848                         p_info("failed to create json writer for btf. falling back to plain output");
 849                         btf__free(btf);
 850                         btf = NULL;
 851                         print_entry_plain(&info, key, value);
 852                 } else {
 853                         struct btf_dumper d = {
 854                                 .btf = btf,
 855                                 .jw = btf_wtr,
 856                                 .is_plain_text = true,
 857                         };
 858
 859                         do_dump_btf(&d, &info, key, value);
 860                         jsonw_destroy(&btf_wtr);
 861                 }
 862         } else {
 863                 print_entry_plain(&info, key, value);
 864         }
 865
 866 exit_free:
 867         free(key);
 868         free(value);
 869         close(fd);
 870         btf__free(btf);
 871
 872         return err;
 873 }
 874
 875 static int do_getnext(int argc, char **argv)
 876 {
 877         struct bpf_map_info info = {};
 878         __u32 len = sizeof(info);
 879         void *key, *nextkey;
 880         int err;
 881         int fd;
 882
 883         if (argc < 2)
 884                 usage();
 885
 886         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 887         if (fd < 0)
 888                 return -1;
 889
 890         key = malloc(info.key_size);
 891         nextkey = malloc(info.key_size);
 892         if (!key || !nextkey) {
 893                 p_err("mem alloc failed");
 894                 err = -1;
 895                 goto exit_free;
 896         }
 897
 898         if (argc) {
 899                 err = parse_elem(argv, &info, key, NULL, info.key_size, 0,
 900                                  NULL, NULL);
 901                 if (err)
 902                         goto exit_free;
 903         } else {
 904                 free(key);
 905                 key = NULL;
 906         }
 907
 908         err = bpf_map_get_next_key(fd, key, nextkey);
 909         if (err) {
 910                 p_err("can't get next key: %s", strerror(errno));
 911                 goto exit_free;
 912         }
 913
 914         if (json_output) {
 915                 jsonw_start_object(json_wtr);
 916                 if (key) {
 917                         jsonw_name(json_wtr, "key");
 918                         print_hex_data_json(key, info.key_size);
 919                 } else {
 920                         jsonw_null_field(json_wtr, "key");
 921                 }
 922                 jsonw_name(json_wtr, "next_key");
 923                 print_hex_data_json(nextkey, info.key_size);
 924                 jsonw_end_object(json_wtr);
 925         } else {
 926                 if (key) {
 927                         printf("key:\n");
 928                         fprint_hex(stdout, key, info.key_size, " ");
 929                         printf("\n");
 930                 } else {
 931                         printf("key: None\n");
 932                 }
 933                 printf("next key:\n");
 934                 fprint_hex(stdout, nextkey, info.key_size, " ");
 935                 printf("\n");
 936         }
 937
 938 exit_free:
 939         free(nextkey);
 940         free(key);
 941         close(fd);
 942
 943         return err;
 944 }
 945
 946 static int do_delete(int argc, char **argv)
 947 {
 948         struct bpf_map_info info = {};
 949         __u32 len = sizeof(info);
 950         void *key;
 951         int err;
 952         int fd;
 953
 954         if (argc < 2)
 955                 usage();
 956
 957         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 958         if (fd < 0)
 959                 return -1;
 960
 961         key = malloc(info.key_size);
 962         if (!key) {
 963                 p_err("mem alloc failed");
 964                 err = -1;
 965                 goto exit_free;
 966         }
 967
 968         err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
 969         if (err)
 970                 goto exit_free;
 971
 972         err = bpf_map_delete_elem(fd, key);
 973         if (err)
 974                 p_err("delete failed: %s", strerror(errno));
 975
 976 exit_free:
 977         free(key);
 978         close(fd);
 979
 980         if (!err && json_output)
 981                 jsonw_null(json_wtr);
 982         return err;
 983 }
 984
 985 static int do_pin(int argc, char **argv)
 986 {
 987         int err;
 988
 989         err = do_pin_any(argc, argv, bpf_map_get_fd_by_id);
 990         if (!err && json_output)
 991                 jsonw_null(json_wtr);
 992         return err;
 993 }
 994
 995 static int do_help(int argc, char **argv)
 996 {
 997         if (json_output) {
 998                 jsonw_null(json_wtr);
 999                 return 0;
1000         }
1001
1002         fprintf(stderr,
1003                 "Usage: %s %s { show | list }   [MAP]\n"
1004                 "       %s %s dump       MAP\n"
1005                 "       %s %s update     MAP  key DATA value VALUE [UPDATE_FLAGS]\n"
1006                 "       %s %s lookup     MAP  key DATA\n"
1007                 "       %s %s getnext    MAP [key DATA]\n"
1008                 "       %s %s delete     MAP  key DATA\n"
1009                 "       %s %s pin        MAP  FILE\n"
1010                 "       %s %s event_pipe MAP [cpu N index M]\n"
1011                 "       %s %s help\n"
1012                 "\n"
1013                 "       " HELP_SPEC_MAP "\n"
1014                 "       DATA := { [hex] BYTES }\n"
1015                 "       " HELP_SPEC_PROGRAM "\n"
1016                 "       VALUE := { DATA | MAP | PROG }\n"
1017                 "       UPDATE_FLAGS := { any | exist | noexist }\n"
1018                 "       " HELP_SPEC_OPTIONS "\n"
1019                 "",
1020                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
1021                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
1022                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]);
1023
1024         return 0;
1025 }
1026
1027 static const struct cmd cmds[] = {
1028         { "show",       do_show },
1029         { "list",       do_show },
1030         { "help",       do_help },
1031         { "dump",       do_dump },
1032         { "update",     do_update },
1033         { "lookup",     do_lookup },
1034         { "getnext",    do_getnext },
1035         { "delete",     do_delete },
1036         { "pin",        do_pin },
1037         { "event_pipe", do_event_pipe },
1038         { 0 }
1039 };
1040
1041 int do_map(int argc, char **argv)
1042 {
1043         return cmd_select(cmds, argc, argv, do_help);
1044 }