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 <linux/kernel.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 "btf.h"
  50 #include "json_writer.h"
  51 #include "main.h"
  52
  53 static const char * const map_type_name[] = {
  54         [BPF_MAP_TYPE_UNSPEC]           = "unspec",
  55         [BPF_MAP_TYPE_HASH]             = "hash",
  56         [BPF_MAP_TYPE_ARRAY]            = "array",
  57         [BPF_MAP_TYPE_PROG_ARRAY]       = "prog_array",
  58         [BPF_MAP_TYPE_PERF_EVENT_ARRAY] = "perf_event_array",
  59         [BPF_MAP_TYPE_PERCPU_HASH]      = "percpu_hash",
  60         [BPF_MAP_TYPE_PERCPU_ARRAY]     = "percpu_array",
  61         [BPF_MAP_TYPE_STACK_TRACE]      = "stack_trace",
  62         [BPF_MAP_TYPE_CGROUP_ARRAY]     = "cgroup_array",
  63         [BPF_MAP_TYPE_LRU_HASH]         = "lru_hash",
  64         [BPF_MAP_TYPE_LRU_PERCPU_HASH]  = "lru_percpu_hash",
  65         [BPF_MAP_TYPE_LPM_TRIE]         = "lpm_trie",
  66         [BPF_MAP_TYPE_ARRAY_OF_MAPS]    = "array_of_maps",
  67         [BPF_MAP_TYPE_HASH_OF_MAPS]     = "hash_of_maps",
  68         [BPF_MAP_TYPE_DEVMAP]           = "devmap",
  69         [BPF_MAP_TYPE_SOCKMAP]          = "sockmap",
  70         [BPF_MAP_TYPE_CPUMAP]           = "cpumap",
  71         [BPF_MAP_TYPE_XSKMAP]           = "xskmap",
  72         [BPF_MAP_TYPE_SOCKHASH]         = "sockhash",
  73         [BPF_MAP_TYPE_CGROUP_STORAGE]   = "cgroup_storage",
  74 };
  75
  76 static bool map_is_per_cpu(__u32 type)
  77 {
  78         return type == BPF_MAP_TYPE_PERCPU_HASH ||
  79                type == BPF_MAP_TYPE_PERCPU_ARRAY ||
  80                type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
  81 }
  82
  83 static bool map_is_map_of_maps(__u32 type)
  84 {
  85         return type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
  86                type == BPF_MAP_TYPE_HASH_OF_MAPS;
  87 }
  88
  89 static bool map_is_map_of_progs(__u32 type)
  90 {
  91         return type == BPF_MAP_TYPE_PROG_ARRAY;
  92 }
  93
  94 static void *alloc_value(struct bpf_map_info *info)
  95 {
  96         if (map_is_per_cpu(info->type))
  97                 return malloc(round_up(info->value_size, 8) *
  98                               get_possible_cpus());
  99         else
 100                 return malloc(info->value_size);
 101 }
 102
 103 int map_parse_fd(int *argc, char ***argv)
 104 {
 105         int fd;
 106
 107         if (is_prefix(**argv, "id")) {
 108                 unsigned int id;
 109                 char *endptr;
 110
 111                 NEXT_ARGP();
 112
 113                 id = strtoul(**argv, &endptr, 0);
 114                 if (*endptr) {
 115                         p_err("can't parse %s as ID", **argv);
 116                         return -1;
 117                 }
 118                 NEXT_ARGP();
 119
 120                 fd = bpf_map_get_fd_by_id(id);
 121                 if (fd < 0)
 122                         p_err("get map by id (%u): %s", id, strerror(errno));
 123                 return fd;
 124         } else if (is_prefix(**argv, "pinned")) {
 125                 char *path;
 126
 127                 NEXT_ARGP();
 128
 129                 path = **argv;
 130                 NEXT_ARGP();
 131
 132                 return open_obj_pinned_any(path, BPF_OBJ_MAP);
 133         }
 134
 135         p_err("expected 'id' or 'pinned', got: '%s'?", **argv);
 136         return -1;
 137 }
 138
 139 int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
 140 {
 141         int err;
 142         int fd;
 143
 144         fd = map_parse_fd(argc, argv);
 145         if (fd < 0)
 146                 return -1;
 147
 148         err = bpf_obj_get_info_by_fd(fd, info, info_len);
 149         if (err) {
 150                 p_err("can't get map info: %s", strerror(errno));
 151                 close(fd);
 152                 return err;
 153         }
 154
 155         return fd;
 156 }
 157
 158 static int do_dump_btf(const struct btf_dumper *d,
 159                        struct bpf_map_info *map_info, void *key,
 160                        void *value)
 161 {
 162         int ret;
 163
 164         /* start of key-value pair */
 165         jsonw_start_object(d->jw);
 166
 167         jsonw_name(d->jw, "key");
 168
 169         ret = btf_dumper_type(d, map_info->btf_key_type_id, key);
 170         if (ret)
 171                 goto err_end_obj;
 172
 173         jsonw_name(d->jw, "value");
 174
 175         ret = btf_dumper_type(d, map_info->btf_value_type_id, value);
 176
 177 err_end_obj:
 178         /* end of key-value pair */
 179         jsonw_end_object(d->jw);
 180
 181         return ret;
 182 }
 183
 184 static int get_btf(struct bpf_map_info *map_info, struct btf **btf)
 185 {
 186         struct bpf_btf_info btf_info = { 0 };
 187         __u32 len = sizeof(btf_info);
 188         __u32 last_size;
 189         int btf_fd;
 190         void *ptr;
 191         int err;
 192
 193         err = 0;
 194         *btf = NULL;
 195         btf_fd = bpf_btf_get_fd_by_id(map_info->btf_id);
 196         if (btf_fd < 0)
 197                 return 0;
 198
 199         /* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so
 200          * let's start with a sane default - 4KiB here - and resize it only if
 201          * bpf_obj_get_info_by_fd() needs a bigger buffer.
 202          */
 203         btf_info.btf_size = 4096;
 204         last_size = btf_info.btf_size;
 205         ptr = malloc(last_size);
 206         if (!ptr) {
 207                 err = -ENOMEM;
 208                 goto exit_free;
 209         }
 210
 211         bzero(ptr, last_size);
 212         btf_info.btf = ptr_to_u64(ptr);
 213         err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
 214
 215         if (!err && btf_info.btf_size > last_size) {
 216                 void *temp_ptr;
 217
 218                 last_size = btf_info.btf_size;
 219                 temp_ptr = realloc(ptr, last_size);
 220                 if (!temp_ptr) {
 221                         err = -ENOMEM;
 222                         goto exit_free;
 223                 }
 224                 ptr = temp_ptr;
 225                 bzero(ptr, last_size);
 226                 btf_info.btf = ptr_to_u64(ptr);
 227                 err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
 228         }
 229
 230         if (err || btf_info.btf_size > last_size) {
 231                 err = errno;
 232                 goto exit_free;
 233         }
 234
 235         *btf = btf__new((__u8 *)btf_info.btf, btf_info.btf_size, NULL);
 236         if (IS_ERR(*btf)) {
 237                 err = PTR_ERR(*btf);
 238                 *btf = NULL;
 239         }
 240
 241 exit_free:
 242         close(btf_fd);
 243         free(ptr);
 244
 245         return err;
 246 }
 247
 248 static json_writer_t *get_btf_writer(void)
 249 {
 250         json_writer_t *jw = jsonw_new(stdout);
 251
 252         if (!jw)
 253                 return NULL;
 254         jsonw_pretty(jw, true);
 255
 256         return jw;
 257 }
 258
 259 static void print_entry_json(struct bpf_map_info *info, unsigned char *key,
 260                              unsigned char *value, struct btf *btf)
 261 {
 262         jsonw_start_object(json_wtr);
 263
 264         if (!map_is_per_cpu(info->type)) {
 265                 jsonw_name(json_wtr, "key");
 266                 print_hex_data_json(key, info->key_size);
 267                 jsonw_name(json_wtr, "value");
 268                 print_hex_data_json(value, info->value_size);
 269                 if (btf) {
 270                         struct btf_dumper d = {
 271                                 .btf = btf,
 272                                 .jw = json_wtr,
 273                                 .is_plain_text = false,
 274                         };
 275
 276                         jsonw_name(json_wtr, "formatted");
 277                         do_dump_btf(&d, info, key, value);
 278                 }
 279         } else {
 280                 unsigned int i, n, step;
 281
 282                 n = get_possible_cpus();
 283                 step = round_up(info->value_size, 8);
 284
 285                 jsonw_name(json_wtr, "key");
 286                 print_hex_data_json(key, info->key_size);
 287
 288                 jsonw_name(json_wtr, "values");
 289                 jsonw_start_array(json_wtr);
 290                 for (i = 0; i < n; i++) {
 291                         jsonw_start_object(json_wtr);
 292
 293                         jsonw_int_field(json_wtr, "cpu", i);
 294
 295                         jsonw_name(json_wtr, "value");
 296                         print_hex_data_json(value + i * step,
 297                                             info->value_size);
 298
 299                         jsonw_end_object(json_wtr);
 300                 }
 301                 jsonw_end_array(json_wtr);
 302         }
 303
 304         jsonw_end_object(json_wtr);
 305 }
 306
 307 static void print_entry_plain(struct bpf_map_info *info, unsigned char *key,
 308                               unsigned char *value)
 309 {
 310         if (!map_is_per_cpu(info->type)) {
 311                 bool single_line, break_names;
 312
 313                 break_names = info->key_size > 16 || info->value_size > 16;
 314                 single_line = info->key_size + info->value_size <= 24 &&
 315                         !break_names;
 316
 317                 printf("key:%c", break_names ? '\n' : ' ');
 318                 fprint_hex(stdout, key, info->key_size, " ");
 319
 320                 printf(single_line ? "  " : "\n");
 321
 322                 printf("value:%c", break_names ? '\n' : ' ');
 323                 fprint_hex(stdout, value, info->value_size, " ");
 324
 325                 printf("\n");
 326         } else {
 327                 unsigned int i, n, step;
 328
 329                 n = get_possible_cpus();
 330                 step = round_up(info->value_size, 8);
 331
 332                 printf("key:\n");
 333                 fprint_hex(stdout, key, info->key_size, " ");
 334                 printf("\n");
 335                 for (i = 0; i < n; i++) {
 336                         printf("value (CPU %02d):%c",
 337                                i, info->value_size > 16 ? '\n' : ' ');
 338                         fprint_hex(stdout, value + i * step,
 339                                    info->value_size, " ");
 340                         printf("\n");
 341                 }
 342         }
 343 }
 344
 345 static char **parse_bytes(char **argv, const char *name, unsigned char *val,
 346                           unsigned int n)
 347 {
 348         unsigned int i = 0, base = 0;
 349         char *endptr;
 350
 351         if (is_prefix(*argv, "hex")) {
 352                 base = 16;
 353                 argv++;
 354         }
 355
 356         while (i < n && argv[i]) {
 357                 val[i] = strtoul(argv[i], &endptr, base);
 358                 if (*endptr) {
 359                         p_err("error parsing byte: %s", argv[i]);
 360                         return NULL;
 361                 }
 362                 i++;
 363         }
 364
 365         if (i != n) {
 366                 p_err("%s expected %d bytes got %d", name, n, i);
 367                 return NULL;
 368         }
 369
 370         return argv + i;
 371 }
 372
 373 static int parse_elem(char **argv, struct bpf_map_info *info,
 374                       void *key, void *value, __u32 key_size, __u32 value_size,
 375                       __u32 *flags, __u32 **value_fd)
 376 {
 377         if (!*argv) {
 378                 if (!key && !value)
 379                         return 0;
 380                 p_err("did not find %s", key ? "key" : "value");
 381                 return -1;
 382         }
 383
 384         if (is_prefix(*argv, "key")) {
 385                 if (!key) {
 386                         if (key_size)
 387                                 p_err("duplicate key");
 388                         else
 389                                 p_err("unnecessary key");
 390                         return -1;
 391                 }
 392
 393                 argv = parse_bytes(argv + 1, "key", key, key_size);
 394                 if (!argv)
 395                         return -1;
 396
 397                 return parse_elem(argv, info, NULL, value, key_size, value_size,
 398                                   flags, value_fd);
 399         } else if (is_prefix(*argv, "value")) {
 400                 int fd;
 401
 402                 if (!value) {
 403                         if (value_size)
 404                                 p_err("duplicate value");
 405                         else
 406                                 p_err("unnecessary value");
 407                         return -1;
 408                 }
 409
 410                 argv++;
 411
 412                 if (map_is_map_of_maps(info->type)) {
 413                         int argc = 2;
 414
 415                         if (value_size != 4) {
 416                                 p_err("value smaller than 4B for map in map?");
 417                                 return -1;
 418                         }
 419                         if (!argv[0] || !argv[1]) {
 420                                 p_err("not enough value arguments for map in map");
 421                                 return -1;
 422                         }
 423
 424                         fd = map_parse_fd(&argc, &argv);
 425                         if (fd < 0)
 426                                 return -1;
 427
 428                         *value_fd = value;
 429                         **value_fd = fd;
 430                 } else if (map_is_map_of_progs(info->type)) {
 431                         int argc = 2;
 432
 433                         if (value_size != 4) {
 434                                 p_err("value smaller than 4B for map of progs?");
 435                                 return -1;
 436                         }
 437                         if (!argv[0] || !argv[1]) {
 438                                 p_err("not enough value arguments for map of progs");
 439                                 return -1;
 440                         }
 441
 442                         fd = prog_parse_fd(&argc, &argv);
 443                         if (fd < 0)
 444                                 return -1;
 445
 446                         *value_fd = value;
 447                         **value_fd = fd;
 448                 } else {
 449                         argv = parse_bytes(argv, "value", value, value_size);
 450                         if (!argv)
 451                                 return -1;
 452                 }
 453
 454                 return parse_elem(argv, info, key, NULL, key_size, value_size,
 455                                   flags, NULL);
 456         } else if (is_prefix(*argv, "any") || is_prefix(*argv, "noexist") ||
 457                    is_prefix(*argv, "exist")) {
 458                 if (!flags) {
 459                         p_err("flags specified multiple times: %s", *argv);
 460                         return -1;
 461                 }
 462
 463                 if (is_prefix(*argv, "any"))
 464                         *flags = BPF_ANY;
 465                 else if (is_prefix(*argv, "noexist"))
 466                         *flags = BPF_NOEXIST;
 467                 else if (is_prefix(*argv, "exist"))
 468                         *flags = BPF_EXIST;
 469
 470                 return parse_elem(argv + 1, info, key, value, key_size,
 471                                   value_size, NULL, value_fd);
 472         }
 473
 474         p_err("expected key or value, got: %s", *argv);
 475         return -1;
 476 }
 477
 478 static int show_map_close_json(int fd, struct bpf_map_info *info)
 479 {
 480         char *memlock;
 481
 482         memlock = get_fdinfo(fd, "memlock");
 483         close(fd);
 484
 485         jsonw_start_object(json_wtr);
 486
 487         jsonw_uint_field(json_wtr, "id", info->id);
 488         if (info->type < ARRAY_SIZE(map_type_name))
 489                 jsonw_string_field(json_wtr, "type",
 490                                    map_type_name[info->type]);
 491         else
 492                 jsonw_uint_field(json_wtr, "type", info->type);
 493
 494         if (*info->name)
 495                 jsonw_string_field(json_wtr, "name", info->name);
 496
 497         jsonw_name(json_wtr, "flags");
 498         jsonw_printf(json_wtr, "%d", info->map_flags);
 499
 500         print_dev_json(info->ifindex, info->netns_dev, info->netns_ino);
 501
 502         jsonw_uint_field(json_wtr, "bytes_key", info->key_size);
 503         jsonw_uint_field(json_wtr, "bytes_value", info->value_size);
 504         jsonw_uint_field(json_wtr, "max_entries", info->max_entries);
 505
 506         if (memlock)
 507                 jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
 508         free(memlock);
 509
 510         if (!hash_empty(map_table.table)) {
 511                 struct pinned_obj *obj;
 512
 513                 jsonw_name(json_wtr, "pinned");
 514                 jsonw_start_array(json_wtr);
 515                 hash_for_each_possible(map_table.table, obj, hash, info->id) {
 516                         if (obj->id == info->id)
 517                                 jsonw_string(json_wtr, obj->path);
 518                 }
 519                 jsonw_end_array(json_wtr);
 520         }
 521
 522         jsonw_end_object(json_wtr);
 523
 524         return 0;
 525 }
 526
 527 static int show_map_close_plain(int fd, struct bpf_map_info *info)
 528 {
 529         char *memlock;
 530
 531         memlock = get_fdinfo(fd, "memlock");
 532         close(fd);
 533
 534         printf("%u: ", info->id);
 535         if (info->type < ARRAY_SIZE(map_type_name))
 536                 printf("%s  ", map_type_name[info->type]);
 537         else
 538                 printf("type %u  ", info->type);
 539
 540         if (*info->name)
 541                 printf("name %s  ", info->name);
 542
 543         printf("flags 0x%x", info->map_flags);
 544         print_dev_plain(info->ifindex, info->netns_dev, info->netns_ino);
 545         printf("\n");
 546         printf("\tkey %uB  value %uB  max_entries %u",
 547                info->key_size, info->value_size, info->max_entries);
 548
 549         if (memlock)
 550                 printf("  memlock %sB", memlock);
 551         free(memlock);
 552
 553         printf("\n");
 554         if (!hash_empty(map_table.table)) {
 555                 struct pinned_obj *obj;
 556
 557                 hash_for_each_possible(map_table.table, obj, hash, info->id) {
 558                         if (obj->id == info->id)
 559                                 printf("\tpinned %s\n", obj->path);
 560                 }
 561         }
 562         return 0;
 563 }
 564
 565 static int do_show(int argc, char **argv)
 566 {
 567         struct bpf_map_info info = {};
 568         __u32 len = sizeof(info);
 569         __u32 id = 0;
 570         int err;
 571         int fd;
 572
 573         if (show_pinned)
 574                 build_pinned_obj_table(&map_table, BPF_OBJ_MAP);
 575
 576         if (argc == 2) {
 577                 fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 578                 if (fd < 0)
 579                         return -1;
 580
 581                 if (json_output)
 582                         return show_map_close_json(fd, &info);
 583                 else
 584                         return show_map_close_plain(fd, &info);
 585         }
 586
 587         if (argc)
 588                 return BAD_ARG();
 589
 590         if (json_output)
 591                 jsonw_start_array(json_wtr);
 592         while (true) {
 593                 err = bpf_map_get_next_id(id, &id);
 594                 if (err) {
 595                         if (errno == ENOENT)
 596                                 break;
 597                         p_err("can't get next map: %s%s", strerror(errno),
 598                               errno == EINVAL ? " -- kernel too old?" : "");
 599                         break;
 600                 }
 601
 602                 fd = bpf_map_get_fd_by_id(id);
 603                 if (fd < 0) {
 604                         if (errno == ENOENT)
 605                                 continue;
 606                         p_err("can't get map by id (%u): %s",
 607                               id, strerror(errno));
 608                         break;
 609                 }
 610
 611                 err = bpf_obj_get_info_by_fd(fd, &info, &len);
 612                 if (err) {
 613                         p_err("can't get map info: %s", strerror(errno));
 614                         close(fd);
 615                         break;
 616                 }
 617
 618                 if (json_output)
 619                         show_map_close_json(fd, &info);
 620                 else
 621                         show_map_close_plain(fd, &info);
 622         }
 623         if (json_output)
 624                 jsonw_end_array(json_wtr);
 625
 626         return errno == ENOENT ? 0 : -1;
 627 }
 628
 629 static int do_dump(int argc, char **argv)
 630 {
 631         struct bpf_map_info info = {};
 632         void *key, *value, *prev_key;
 633         unsigned int num_elems = 0;
 634         __u32 len = sizeof(info);
 635         json_writer_t *btf_wtr;
 636         struct btf *btf = NULL;
 637         int err;
 638         int fd;
 639
 640         if (argc != 2)
 641                 usage();
 642
 643         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 644         if (fd < 0)
 645                 return -1;
 646
 647         if (map_is_map_of_maps(info.type) || map_is_map_of_progs(info.type)) {
 648                 p_err("Dumping maps of maps and program maps not supported");
 649                 close(fd);
 650                 return -1;
 651         }
 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         prev_key = NULL;
 662
 663         err = get_btf(&info, &btf);
 664         if (err) {
 665                 p_err("failed to get btf");
 666                 goto exit_free;
 667         }
 668
 669         if (json_output)
 670                 jsonw_start_array(json_wtr);
 671         else
 672                 if (btf) {
 673                         btf_wtr = get_btf_writer();
 674                         if (!btf_wtr) {
 675                                 p_info("failed to create json writer for btf. falling back to plain output");
 676                                 btf__free(btf);
 677                                 btf = NULL;
 678                         } else {
 679                                 jsonw_start_array(btf_wtr);
 680                         }
 681                 }
 682
 683         while (true) {
 684                 err = bpf_map_get_next_key(fd, prev_key, key);
 685                 if (err) {
 686                         if (errno == ENOENT)
 687                                 err = 0;
 688                         break;
 689                 }
 690
 691                 if (!bpf_map_lookup_elem(fd, key, value)) {
 692                         if (json_output)
 693                                 print_entry_json(&info, key, value, btf);
 694                         else
 695                                 if (btf) {
 696                                         struct btf_dumper d = {
 697                                                 .btf = btf,
 698                                                 .jw = btf_wtr,
 699                                                 .is_plain_text = true,
 700                                         };
 701
 702                                         do_dump_btf(&d, &info, key, value);
 703                                 } else {
 704                                         print_entry_plain(&info, key, value);
 705                                 }
 706                 } else {
 707                         if (json_output) {
 708                                 jsonw_name(json_wtr, "key");
 709                                 print_hex_data_json(key, info.key_size);
 710                                 jsonw_name(json_wtr, "value");
 711                                 jsonw_start_object(json_wtr);
 712                                 jsonw_string_field(json_wtr, "error",
 713                                                    "can't lookup element");
 714                                 jsonw_end_object(json_wtr);
 715                         } else {
 716                                 p_info("can't lookup element with key: ");
 717                                 fprint_hex(stderr, key, info.key_size, " ");
 718                                 fprintf(stderr, "\n");
 719                         }
 720                 }
 721
 722                 prev_key = key;
 723                 num_elems++;
 724         }
 725
 726         if (json_output)
 727                 jsonw_end_array(json_wtr);
 728         else if (btf) {
 729                 jsonw_end_array(btf_wtr);
 730                 jsonw_destroy(&btf_wtr);
 731         } else {
 732                 printf("Found %u element%s\n", num_elems,
 733                        num_elems != 1 ? "s" : "");
 734         }
 735
 736 exit_free:
 737         free(key);
 738         free(value);
 739         close(fd);
 740         btf__free(btf);
 741
 742         return err;
 743 }
 744
 745 static int do_update(int argc, char **argv)
 746 {
 747         struct bpf_map_info info = {};
 748         __u32 len = sizeof(info);
 749         __u32 *value_fd = NULL;
 750         __u32 flags = BPF_ANY;
 751         void *key, *value;
 752         int fd, err;
 753
 754         if (argc < 2)
 755                 usage();
 756
 757         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 758         if (fd < 0)
 759                 return -1;
 760
 761         key = malloc(info.key_size);
 762         value = alloc_value(&info);
 763         if (!key || !value) {
 764                 p_err("mem alloc failed");
 765                 err = -1;
 766                 goto exit_free;
 767         }
 768
 769         err = parse_elem(argv, &info, key, value, info.key_size,
 770                          info.value_size, &flags, &value_fd);
 771         if (err)
 772                 goto exit_free;
 773
 774         err = bpf_map_update_elem(fd, key, value, flags);
 775         if (err) {
 776                 p_err("update failed: %s", strerror(errno));
 777                 goto exit_free;
 778         }
 779
 780 exit_free:
 781         if (value_fd)
 782                 close(*value_fd);
 783         free(key);
 784         free(value);
 785         close(fd);
 786
 787         if (!err && json_output)
 788                 jsonw_null(json_wtr);
 789         return err;
 790 }
 791
 792 static int do_lookup(int argc, char **argv)
 793 {
 794         struct bpf_map_info info = {};
 795         __u32 len = sizeof(info);
 796         json_writer_t *btf_wtr;
 797         struct btf *btf = NULL;
 798         void *key, *value;
 799         int err;
 800         int fd;
 801
 802         if (argc < 2)
 803                 usage();
 804
 805         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 806         if (fd < 0)
 807                 return -1;
 808
 809         key = malloc(info.key_size);
 810         value = alloc_value(&info);
 811         if (!key || !value) {
 812                 p_err("mem alloc failed");
 813                 err = -1;
 814                 goto exit_free;
 815         }
 816
 817         err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
 818         if (err)
 819                 goto exit_free;
 820
 821         err = bpf_map_lookup_elem(fd, key, value);
 822         if (err) {
 823                 if (errno == ENOENT) {
 824                         if (json_output) {
 825                                 jsonw_null(json_wtr);
 826                         } else {
 827                                 printf("key:\n");
 828                                 fprint_hex(stdout, key, info.key_size, " ");
 829                                 printf("\n\nNot found\n");
 830                         }
 831                 } else {
 832                         p_err("lookup failed: %s", strerror(errno));
 833                 }
 834
 835                 goto exit_free;
 836         }
 837
 838         /* here means bpf_map_lookup_elem() succeeded */
 839         err = get_btf(&info, &btf);
 840         if (err) {
 841                 p_err("failed to get btf");
 842                 goto exit_free;
 843         }
 844
 845         if (json_output) {
 846                 print_entry_json(&info, key, value, btf);
 847         } else if (btf) {
 848                 /* if here json_wtr wouldn't have been initialised,
 849                  * so let's create separate writer for btf
 850                  */
 851                 btf_wtr = get_btf_writer();
 852                 if (!btf_wtr) {
 853                         p_info("failed to create json writer for btf. falling back to plain output");
 854                         btf__free(btf);
 855                         btf = NULL;
 856                         print_entry_plain(&info, key, value);
 857                 } else {
 858                         struct btf_dumper d = {
 859                                 .btf = btf,
 860                                 .jw = btf_wtr,
 861                                 .is_plain_text = true,
 862                         };
 863
 864                         do_dump_btf(&d, &info, key, value);
 865                         jsonw_destroy(&btf_wtr);
 866                 }
 867         } else {
 868                 print_entry_plain(&info, key, value);
 869         }
 870
 871 exit_free:
 872         free(key);
 873         free(value);
 874         close(fd);
 875         btf__free(btf);
 876
 877         return err;
 878 }
 879
 880 static int do_getnext(int argc, char **argv)
 881 {
 882         struct bpf_map_info info = {};
 883         __u32 len = sizeof(info);
 884         void *key, *nextkey;
 885         int err;
 886         int fd;
 887
 888         if (argc < 2)
 889                 usage();
 890
 891         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 892         if (fd < 0)
 893                 return -1;
 894
 895         key = malloc(info.key_size);
 896         nextkey = malloc(info.key_size);
 897         if (!key || !nextkey) {
 898                 p_err("mem alloc failed");
 899                 err = -1;
 900                 goto exit_free;
 901         }
 902
 903         if (argc) {
 904                 err = parse_elem(argv, &info, key, NULL, info.key_size, 0,
 905                                  NULL, NULL);
 906                 if (err)
 907                         goto exit_free;
 908         } else {
 909                 free(key);
 910                 key = NULL;
 911         }
 912
 913         err = bpf_map_get_next_key(fd, key, nextkey);
 914         if (err) {
 915                 p_err("can't get next key: %s", strerror(errno));
 916                 goto exit_free;
 917         }
 918
 919         if (json_output) {
 920                 jsonw_start_object(json_wtr);
 921                 if (key) {
 922                         jsonw_name(json_wtr, "key");
 923                         print_hex_data_json(key, info.key_size);
 924                 } else {
 925                         jsonw_null_field(json_wtr, "key");
 926                 }
 927                 jsonw_name(json_wtr, "next_key");
 928                 print_hex_data_json(nextkey, info.key_size);
 929                 jsonw_end_object(json_wtr);
 930         } else {
 931                 if (key) {
 932                         printf("key:\n");
 933                         fprint_hex(stdout, key, info.key_size, " ");
 934                         printf("\n");
 935                 } else {
 936                         printf("key: None\n");
 937                 }
 938                 printf("next key:\n");
 939                 fprint_hex(stdout, nextkey, info.key_size, " ");
 940                 printf("\n");
 941         }
 942
 943 exit_free:
 944         free(nextkey);
 945         free(key);
 946         close(fd);
 947
 948         return err;
 949 }
 950
 951 static int do_delete(int argc, char **argv)
 952 {
 953         struct bpf_map_info info = {};
 954         __u32 len = sizeof(info);
 955         void *key;
 956         int err;
 957         int fd;
 958
 959         if (argc < 2)
 960                 usage();
 961
 962         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 963         if (fd < 0)
 964                 return -1;
 965
 966         key = malloc(info.key_size);
 967         if (!key) {
 968                 p_err("mem alloc failed");
 969                 err = -1;
 970                 goto exit_free;
 971         }
 972
 973         err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
 974         if (err)
 975                 goto exit_free;
 976
 977         err = bpf_map_delete_elem(fd, key);
 978         if (err)
 979                 p_err("delete failed: %s", strerror(errno));
 980
 981 exit_free:
 982         free(key);
 983         close(fd);
 984
 985         if (!err && json_output)
 986                 jsonw_null(json_wtr);
 987         return err;
 988 }
 989
 990 static int do_pin(int argc, char **argv)
 991 {
 992         int err;
 993
 994         err = do_pin_any(argc, argv, bpf_map_get_fd_by_id);
 995         if (!err && json_output)
 996                 jsonw_null(json_wtr);
 997         return err;
 998 }
 999
1000 static int do_help(int argc, char **argv)
1001 {
1002         if (json_output) {
1003                 jsonw_null(json_wtr);
1004                 return 0;
1005         }
1006
1007         fprintf(stderr,
1008                 "Usage: %s %s { show | list }   [MAP]\n"
1009                 "       %s %s dump       MAP\n"
1010                 "       %s %s update     MAP  key DATA value VALUE [UPDATE_FLAGS]\n"
1011                 "       %s %s lookup     MAP  key DATA\n"
1012                 "       %s %s getnext    MAP [key DATA]\n"
1013                 "       %s %s delete     MAP  key DATA\n"
1014                 "       %s %s pin        MAP  FILE\n"
1015                 "       %s %s event_pipe MAP [cpu N index M]\n"
1016                 "       %s %s help\n"
1017                 "\n"
1018                 "       " HELP_SPEC_MAP "\n"
1019                 "       DATA := { [hex] BYTES }\n"
1020                 "       " HELP_SPEC_PROGRAM "\n"
1021                 "       VALUE := { DATA | MAP | PROG }\n"
1022                 "       UPDATE_FLAGS := { any | exist | noexist }\n"
1023                 "       " HELP_SPEC_OPTIONS "\n"
1024                 "",
1025                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
1026                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
1027                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]);
1028
1029         return 0;
1030 }
1031
1032 static const struct cmd cmds[] = {
1033         { "show",       do_show },
1034         { "list",       do_show },
1035         { "help",       do_help },
1036         { "dump",       do_dump },
1037         { "update",     do_update },
1038         { "lookup",     do_lookup },
1039         { "getnext",    do_getnext },
1040         { "delete",     do_delete },
1041         { "pin",        do_pin },
1042         { "event_pipe", do_event_pipe },
1043         { 0 }
1044 };
1045
1046 int do_map(int argc, char **argv)
1047 {
1048         return cmd_select(cmds, argc, argv, do_help);
1049 }