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_SOCKHASH]         = "sockhash",
  72         [BPF_MAP_TYPE_CGROUP_STORAGE]   = "cgroup_storage",
  73 };
  74
  75 static bool map_is_per_cpu(__u32 type)
  76 {
  77         return type == BPF_MAP_TYPE_PERCPU_HASH ||
  78                type == BPF_MAP_TYPE_PERCPU_ARRAY ||
  79                type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
  80 }
  81
  82 static bool map_is_map_of_maps(__u32 type)
  83 {
  84         return type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
  85                type == BPF_MAP_TYPE_HASH_OF_MAPS;
  86 }
  87
  88 static bool map_is_map_of_progs(__u32 type)
  89 {
  90         return type == BPF_MAP_TYPE_PROG_ARRAY;
  91 }
  92
  93 static void *alloc_value(struct bpf_map_info *info)
  94 {
  95         if (map_is_per_cpu(info->type))
  96                 return malloc(round_up(info->value_size, 8) *
  97                               get_possible_cpus());
  98         else
  99                 return malloc(info->value_size);
 100 }
 101
 102 int map_parse_fd(int *argc, char ***argv)
 103 {
 104         int fd;
 105
 106         if (is_prefix(**argv, "id")) {
 107                 unsigned int id;
 108                 char *endptr;
 109
 110                 NEXT_ARGP();
 111
 112                 id = strtoul(**argv, &endptr, 0);
 113                 if (*endptr) {
 114                         p_err("can't parse %s as ID", **argv);
 115                         return -1;
 116                 }
 117                 NEXT_ARGP();
 118
 119                 fd = bpf_map_get_fd_by_id(id);
 120                 if (fd < 0)
 121                         p_err("get map by id (%u): %s", id, strerror(errno));
 122                 return fd;
 123         } else if (is_prefix(**argv, "pinned")) {
 124                 char *path;
 125
 126                 NEXT_ARGP();
 127
 128                 path = **argv;
 129                 NEXT_ARGP();
 130
 131                 return open_obj_pinned_any(path, BPF_OBJ_MAP);
 132         }
 133
 134         p_err("expected 'id' or 'pinned', got: '%s'?", **argv);
 135         return -1;
 136 }
 137
 138 int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
 139 {
 140         int err;
 141         int fd;
 142
 143         fd = map_parse_fd(argc, argv);
 144         if (fd < 0)
 145                 return -1;
 146
 147         err = bpf_obj_get_info_by_fd(fd, info, info_len);
 148         if (err) {
 149                 p_err("can't get map info: %s", strerror(errno));
 150                 close(fd);
 151                 return err;
 152         }
 153
 154         return fd;
 155 }
 156
 157 static int do_dump_btf(const struct btf_dumper *d,
 158                        struct bpf_map_info *map_info, void *key,
 159                        void *value)
 160 {
 161         int ret;
 162
 163         /* start of key-value pair */
 164         jsonw_start_object(d->jw);
 165
 166         jsonw_name(d->jw, "key");
 167
 168         ret = btf_dumper_type(d, map_info->btf_key_type_id, key);
 169         if (ret)
 170                 goto err_end_obj;
 171
 172         jsonw_name(d->jw, "value");
 173
 174         ret = btf_dumper_type(d, map_info->btf_value_type_id, value);
 175
 176 err_end_obj:
 177         /* end of key-value pair */
 178         jsonw_end_object(d->jw);
 179
 180         return ret;
 181 }
 182
 183 static int get_btf(struct bpf_map_info *map_info, struct btf **btf)
 184 {
 185         struct bpf_btf_info btf_info = { 0 };
 186         __u32 len = sizeof(btf_info);
 187         __u32 last_size;
 188         int btf_fd;
 189         void *ptr;
 190         int err;
 191
 192         err = 0;
 193         *btf = NULL;
 194         btf_fd = bpf_btf_get_fd_by_id(map_info->btf_id);
 195         if (btf_fd < 0)
 196                 return 0;
 197
 198         /* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so
 199          * let's start with a sane default - 4KiB here - and resize it only if
 200          * bpf_obj_get_info_by_fd() needs a bigger buffer.
 201          */
 202         btf_info.btf_size = 4096;
 203         last_size = btf_info.btf_size;
 204         ptr = malloc(last_size);
 205         if (!ptr) {
 206                 err = -ENOMEM;
 207                 goto exit_free;
 208         }
 209
 210         bzero(ptr, last_size);
 211         btf_info.btf = ptr_to_u64(ptr);
 212         err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
 213
 214         if (!err && btf_info.btf_size > last_size) {
 215                 void *temp_ptr;
 216
 217                 last_size = btf_info.btf_size;
 218                 temp_ptr = realloc(ptr, last_size);
 219                 if (!temp_ptr) {
 220                         err = -ENOMEM;
 221                         goto exit_free;
 222                 }
 223                 ptr = temp_ptr;
 224                 bzero(ptr, last_size);
 225                 btf_info.btf = ptr_to_u64(ptr);
 226                 err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
 227         }
 228
 229         if (err || btf_info.btf_size > last_size) {
 230                 err = errno;
 231                 goto exit_free;
 232         }
 233
 234         *btf = btf__new((__u8 *)btf_info.btf, btf_info.btf_size, NULL);
 235         if (IS_ERR(*btf)) {
 236                 err = PTR_ERR(*btf);
 237                 *btf = NULL;
 238         }
 239
 240 exit_free:
 241         close(btf_fd);
 242         free(ptr);
 243
 244         return err;
 245 }
 246
 247 static json_writer_t *get_btf_writer(void)
 248 {
 249         json_writer_t *jw = jsonw_new(stdout);
 250
 251         if (!jw)
 252                 return NULL;
 253         jsonw_pretty(jw, true);
 254
 255         return jw;
 256 }
 257
 258 static void print_entry_json(struct bpf_map_info *info, unsigned char *key,
 259                              unsigned char *value, struct btf *btf)
 260 {
 261         jsonw_start_object(json_wtr);
 262
 263         if (!map_is_per_cpu(info->type)) {
 264                 jsonw_name(json_wtr, "key");
 265                 print_hex_data_json(key, info->key_size);
 266                 jsonw_name(json_wtr, "value");
 267                 print_hex_data_json(value, info->value_size);
 268                 if (btf) {
 269                         struct btf_dumper d = {
 270                                 .btf = btf,
 271                                 .jw = json_wtr,
 272                                 .is_plain_text = false,
 273                         };
 274
 275                         jsonw_name(json_wtr, "formatted");
 276                         do_dump_btf(&d, info, key, value);
 277                 }
 278         } else {
 279                 unsigned int i, n, step;
 280
 281                 n = get_possible_cpus();
 282                 step = round_up(info->value_size, 8);
 283
 284                 jsonw_name(json_wtr, "key");
 285                 print_hex_data_json(key, info->key_size);
 286
 287                 jsonw_name(json_wtr, "values");
 288                 jsonw_start_array(json_wtr);
 289                 for (i = 0; i < n; i++) {
 290                         jsonw_start_object(json_wtr);
 291
 292                         jsonw_int_field(json_wtr, "cpu", i);
 293
 294                         jsonw_name(json_wtr, "value");
 295                         print_hex_data_json(value + i * step,
 296                                             info->value_size);
 297
 298                         jsonw_end_object(json_wtr);
 299                 }
 300                 jsonw_end_array(json_wtr);
 301         }
 302
 303         jsonw_end_object(json_wtr);
 304 }
 305
 306 static void print_entry_plain(struct bpf_map_info *info, unsigned char *key,
 307                               unsigned char *value)
 308 {
 309         if (!map_is_per_cpu(info->type)) {
 310                 bool single_line, break_names;
 311
 312                 break_names = info->key_size > 16 || info->value_size > 16;
 313                 single_line = info->key_size + info->value_size <= 24 &&
 314                         !break_names;
 315
 316                 printf("key:%c", break_names ? '\n' : ' ');
 317                 fprint_hex(stdout, key, info->key_size, " ");
 318
 319                 printf(single_line ? "  " : "\n");
 320
 321                 printf("value:%c", break_names ? '\n' : ' ');
 322                 fprint_hex(stdout, value, info->value_size, " ");
 323
 324                 printf("\n");
 325         } else {
 326                 unsigned int i, n, step;
 327
 328                 n = get_possible_cpus();
 329                 step = round_up(info->value_size, 8);
 330
 331                 printf("key:\n");
 332                 fprint_hex(stdout, key, info->key_size, " ");
 333                 printf("\n");
 334                 for (i = 0; i < n; i++) {
 335                         printf("value (CPU %02d):%c",
 336                                i, info->value_size > 16 ? '\n' : ' ');
 337                         fprint_hex(stdout, value + i * step,
 338                                    info->value_size, " ");
 339                         printf("\n");
 340                 }
 341         }
 342 }
 343
 344 static char **parse_bytes(char **argv, const char *name, unsigned char *val,
 345                           unsigned int n)
 346 {
 347         unsigned int i = 0, base = 0;
 348         char *endptr;
 349
 350         if (is_prefix(*argv, "hex")) {
 351                 base = 16;
 352                 argv++;
 353         }
 354
 355         while (i < n && argv[i]) {
 356                 val[i] = strtoul(argv[i], &endptr, base);
 357                 if (*endptr) {
 358                         p_err("error parsing byte: %s", argv[i]);
 359                         return NULL;
 360                 }
 361                 i++;
 362         }
 363
 364         if (i != n) {
 365                 p_err("%s expected %d bytes got %d", name, n, i);
 366                 return NULL;
 367         }
 368
 369         return argv + i;
 370 }
 371
 372 static int parse_elem(char **argv, struct bpf_map_info *info,
 373                       void *key, void *value, __u32 key_size, __u32 value_size,
 374                       __u32 *flags, __u32 **value_fd)
 375 {
 376         if (!*argv) {
 377                 if (!key && !value)
 378                         return 0;
 379                 p_err("did not find %s", key ? "key" : "value");
 380                 return -1;
 381         }
 382
 383         if (is_prefix(*argv, "key")) {
 384                 if (!key) {
 385                         if (key_size)
 386                                 p_err("duplicate key");
 387                         else
 388                                 p_err("unnecessary key");
 389                         return -1;
 390                 }
 391
 392                 argv = parse_bytes(argv + 1, "key", key, key_size);
 393                 if (!argv)
 394                         return -1;
 395
 396                 return parse_elem(argv, info, NULL, value, key_size, value_size,
 397                                   flags, value_fd);
 398         } else if (is_prefix(*argv, "value")) {
 399                 int fd;
 400
 401                 if (!value) {
 402                         if (value_size)
 403                                 p_err("duplicate value");
 404                         else
 405                                 p_err("unnecessary value");
 406                         return -1;
 407                 }
 408
 409                 argv++;
 410
 411                 if (map_is_map_of_maps(info->type)) {
 412                         int argc = 2;
 413
 414                         if (value_size != 4) {
 415                                 p_err("value smaller than 4B for map in map?");
 416                                 return -1;
 417                         }
 418                         if (!argv[0] || !argv[1]) {
 419                                 p_err("not enough value arguments for map in map");
 420                                 return -1;
 421                         }
 422
 423                         fd = map_parse_fd(&argc, &argv);
 424                         if (fd < 0)
 425                                 return -1;
 426
 427                         *value_fd = value;
 428                         **value_fd = fd;
 429                 } else if (map_is_map_of_progs(info->type)) {
 430                         int argc = 2;
 431
 432                         if (value_size != 4) {
 433                                 p_err("value smaller than 4B for map of progs?");
 434                                 return -1;
 435                         }
 436                         if (!argv[0] || !argv[1]) {
 437                                 p_err("not enough value arguments for map of progs");
 438                                 return -1;
 439                         }
 440
 441                         fd = prog_parse_fd(&argc, &argv);
 442                         if (fd < 0)
 443                                 return -1;
 444
 445                         *value_fd = value;
 446                         **value_fd = fd;
 447                 } else {
 448                         argv = parse_bytes(argv, "value", value, value_size);
 449                         if (!argv)
 450                                 return -1;
 451                 }
 452
 453                 return parse_elem(argv, info, key, NULL, key_size, value_size,
 454                                   flags, NULL);
 455         } else if (is_prefix(*argv, "any") || is_prefix(*argv, "noexist") ||
 456                    is_prefix(*argv, "exist")) {
 457                 if (!flags) {
 458                         p_err("flags specified multiple times: %s", *argv);
 459                         return -1;
 460                 }
 461
 462                 if (is_prefix(*argv, "any"))
 463                         *flags = BPF_ANY;
 464                 else if (is_prefix(*argv, "noexist"))
 465                         *flags = BPF_NOEXIST;
 466                 else if (is_prefix(*argv, "exist"))
 467                         *flags = BPF_EXIST;
 468
 469                 return parse_elem(argv + 1, info, key, value, key_size,
 470                                   value_size, NULL, value_fd);
 471         }
 472
 473         p_err("expected key or value, got: %s", *argv);
 474         return -1;
 475 }
 476
 477 static int show_map_close_json(int fd, struct bpf_map_info *info)
 478 {
 479         char *memlock;
 480
 481         memlock = get_fdinfo(fd, "memlock");
 482         close(fd);
 483
 484         jsonw_start_object(json_wtr);
 485
 486         jsonw_uint_field(json_wtr, "id", info->id);
 487         if (info->type < ARRAY_SIZE(map_type_name))
 488                 jsonw_string_field(json_wtr, "type",
 489                                    map_type_name[info->type]);
 490         else
 491                 jsonw_uint_field(json_wtr, "type", info->type);
 492
 493         if (*info->name)
 494                 jsonw_string_field(json_wtr, "name", info->name);
 495
 496         jsonw_name(json_wtr, "flags");
 497         jsonw_printf(json_wtr, "%d", info->map_flags);
 498
 499         print_dev_json(info->ifindex, info->netns_dev, info->netns_ino);
 500
 501         jsonw_uint_field(json_wtr, "bytes_key", info->key_size);
 502         jsonw_uint_field(json_wtr, "bytes_value", info->value_size);
 503         jsonw_uint_field(json_wtr, "max_entries", info->max_entries);
 504
 505         if (memlock)
 506                 jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
 507         free(memlock);
 508
 509         if (!hash_empty(map_table.table)) {
 510                 struct pinned_obj *obj;
 511
 512                 jsonw_name(json_wtr, "pinned");
 513                 jsonw_start_array(json_wtr);
 514                 hash_for_each_possible(map_table.table, obj, hash, info->id) {
 515                         if (obj->id == info->id)
 516                                 jsonw_string(json_wtr, obj->path);
 517                 }
 518                 jsonw_end_array(json_wtr);
 519         }
 520
 521         jsonw_end_object(json_wtr);
 522
 523         return 0;
 524 }
 525
 526 static int show_map_close_plain(int fd, struct bpf_map_info *info)
 527 {
 528         char *memlock;
 529
 530         memlock = get_fdinfo(fd, "memlock");
 531         close(fd);
 532
 533         printf("%u: ", info->id);
 534         if (info->type < ARRAY_SIZE(map_type_name))
 535                 printf("%s  ", map_type_name[info->type]);
 536         else
 537                 printf("type %u  ", info->type);
 538
 539         if (*info->name)
 540                 printf("name %s  ", info->name);
 541
 542         printf("flags 0x%x", info->map_flags);
 543         print_dev_plain(info->ifindex, info->netns_dev, info->netns_ino);
 544         printf("\n");
 545         printf("\tkey %uB  value %uB  max_entries %u",
 546                info->key_size, info->value_size, info->max_entries);
 547
 548         if (memlock)
 549                 printf("  memlock %sB", memlock);
 550         free(memlock);
 551
 552         printf("\n");
 553         if (!hash_empty(map_table.table)) {
 554                 struct pinned_obj *obj;
 555
 556                 hash_for_each_possible(map_table.table, obj, hash, info->id) {
 557                         if (obj->id == info->id)
 558                                 printf("\tpinned %s\n", obj->path);
 559                 }
 560         }
 561         return 0;
 562 }
 563
 564 static int do_show(int argc, char **argv)
 565 {
 566         struct bpf_map_info info = {};
 567         __u32 len = sizeof(info);
 568         __u32 id = 0;
 569         int err;
 570         int fd;
 571
 572         if (show_pinned)
 573                 build_pinned_obj_table(&map_table, BPF_OBJ_MAP);
 574
 575         if (argc == 2) {
 576                 fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 577                 if (fd < 0)
 578                         return -1;
 579
 580                 if (json_output)
 581                         return show_map_close_json(fd, &info);
 582                 else
 583                         return show_map_close_plain(fd, &info);
 584         }
 585
 586         if (argc)
 587                 return BAD_ARG();
 588
 589         if (json_output)
 590                 jsonw_start_array(json_wtr);
 591         while (true) {
 592                 err = bpf_map_get_next_id(id, &id);
 593                 if (err) {
 594                         if (errno == ENOENT)
 595                                 break;
 596                         p_err("can't get next map: %s%s", strerror(errno),
 597                               errno == EINVAL ? " -- kernel too old?" : "");
 598                         break;
 599                 }
 600
 601                 fd = bpf_map_get_fd_by_id(id);
 602                 if (fd < 0) {
 603                         if (errno == ENOENT)
 604                                 continue;
 605                         p_err("can't get map by id (%u): %s",
 606                               id, strerror(errno));
 607                         break;
 608                 }
 609
 610                 err = bpf_obj_get_info_by_fd(fd, &info, &len);
 611                 if (err) {
 612                         p_err("can't get map info: %s", strerror(errno));
 613                         close(fd);
 614                         break;
 615                 }
 616
 617                 if (json_output)
 618                         show_map_close_json(fd, &info);
 619                 else
 620                         show_map_close_plain(fd, &info);
 621         }
 622         if (json_output)
 623                 jsonw_end_array(json_wtr);
 624
 625         return errno == ENOENT ? 0 : -1;
 626 }
 627
 628 static int do_dump(int argc, char **argv)
 629 {
 630         struct bpf_map_info info = {};
 631         void *key, *value, *prev_key;
 632         unsigned int num_elems = 0;
 633         __u32 len = sizeof(info);
 634         json_writer_t *btf_wtr;
 635         struct btf *btf = NULL;
 636         int err;
 637         int fd;
 638
 639         if (argc != 2)
 640                 usage();
 641
 642         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 643         if (fd < 0)
 644                 return -1;
 645
 646         if (map_is_map_of_maps(info.type) || map_is_map_of_progs(info.type)) {
 647                 p_err("Dumping maps of maps and program maps not supported");
 648                 close(fd);
 649                 return -1;
 650         }
 651
 652         key = malloc(info.key_size);
 653         value = alloc_value(&info);
 654         if (!key || !value) {
 655                 p_err("mem alloc failed");
 656                 err = -1;
 657                 goto exit_free;
 658         }
 659
 660         prev_key = NULL;
 661
 662         err = get_btf(&info, &btf);
 663         if (err) {
 664                 p_err("failed to get btf");
 665                 goto exit_free;
 666         }
 667
 668         if (json_output)
 669                 jsonw_start_array(json_wtr);
 670         else
 671                 if (btf) {
 672                         btf_wtr = get_btf_writer();
 673                         if (!btf_wtr) {
 674                                 p_info("failed to create json writer for btf. falling back to plain output");
 675                                 btf__free(btf);
 676                                 btf = NULL;
 677                         } else {
 678                                 jsonw_start_array(btf_wtr);
 679                         }
 680                 }
 681
 682         while (true) {
 683                 err = bpf_map_get_next_key(fd, prev_key, key);
 684                 if (err) {
 685                         if (errno == ENOENT)
 686                                 err = 0;
 687                         break;
 688                 }
 689
 690                 if (!bpf_map_lookup_elem(fd, key, value)) {
 691                         if (json_output)
 692                                 print_entry_json(&info, key, value, btf);
 693                         else
 694                                 if (btf) {
 695                                         struct btf_dumper d = {
 696                                                 .btf = btf,
 697                                                 .jw = btf_wtr,
 698                                                 .is_plain_text = true,
 699                                         };
 700
 701                                         do_dump_btf(&d, &info, key, value);
 702                                 } else {
 703                                         print_entry_plain(&info, key, value);
 704                                 }
 705                 } else {
 706                         if (json_output) {
 707                                 jsonw_name(json_wtr, "key");
 708                                 print_hex_data_json(key, info.key_size);
 709                                 jsonw_name(json_wtr, "value");
 710                                 jsonw_start_object(json_wtr);
 711                                 jsonw_string_field(json_wtr, "error",
 712                                                    "can't lookup element");
 713                                 jsonw_end_object(json_wtr);
 714                         } else {
 715                                 p_info("can't lookup element with key: ");
 716                                 fprint_hex(stderr, key, info.key_size, " ");
 717                                 fprintf(stderr, "\n");
 718                         }
 719                 }
 720
 721                 prev_key = key;
 722                 num_elems++;
 723         }
 724
 725         if (json_output)
 726                 jsonw_end_array(json_wtr);
 727         else if (btf) {
 728                 jsonw_end_array(btf_wtr);
 729                 jsonw_destroy(&btf_wtr);
 730         } else {
 731                 printf("Found %u element%s\n", num_elems,
 732                        num_elems != 1 ? "s" : "");
 733         }
 734
 735 exit_free:
 736         free(key);
 737         free(value);
 738         close(fd);
 739         btf__free(btf);
 740
 741         return err;
 742 }
 743
 744 static int do_update(int argc, char **argv)
 745 {
 746         struct bpf_map_info info = {};
 747         __u32 len = sizeof(info);
 748         __u32 *value_fd = NULL;
 749         __u32 flags = BPF_ANY;
 750         void *key, *value;
 751         int fd, err;
 752
 753         if (argc < 2)
 754                 usage();
 755
 756         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 757         if (fd < 0)
 758                 return -1;
 759
 760         key = malloc(info.key_size);
 761         value = alloc_value(&info);
 762         if (!key || !value) {
 763                 p_err("mem alloc failed");
 764                 err = -1;
 765                 goto exit_free;
 766         }
 767
 768         err = parse_elem(argv, &info, key, value, info.key_size,
 769                          info.value_size, &flags, &value_fd);
 770         if (err)
 771                 goto exit_free;
 772
 773         err = bpf_map_update_elem(fd, key, value, flags);
 774         if (err) {
 775                 p_err("update failed: %s", strerror(errno));
 776                 goto exit_free;
 777         }
 778
 779 exit_free:
 780         if (value_fd)
 781                 close(*value_fd);
 782         free(key);
 783         free(value);
 784         close(fd);
 785
 786         if (!err && json_output)
 787                 jsonw_null(json_wtr);
 788         return err;
 789 }
 790
 791 static int do_lookup(int argc, char **argv)
 792 {
 793         struct bpf_map_info info = {};
 794         __u32 len = sizeof(info);
 795         json_writer_t *btf_wtr;
 796         struct btf *btf = NULL;
 797         void *key, *value;
 798         int err;
 799         int fd;
 800
 801         if (argc < 2)
 802                 usage();
 803
 804         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 805         if (fd < 0)
 806                 return -1;
 807
 808         key = malloc(info.key_size);
 809         value = alloc_value(&info);
 810         if (!key || !value) {
 811                 p_err("mem alloc failed");
 812                 err = -1;
 813                 goto exit_free;
 814         }
 815
 816         err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
 817         if (err)
 818                 goto exit_free;
 819
 820         err = bpf_map_lookup_elem(fd, key, value);
 821         if (err) {
 822                 if (errno == ENOENT) {
 823                         if (json_output) {
 824                                 jsonw_null(json_wtr);
 825                         } else {
 826                                 printf("key:\n");
 827                                 fprint_hex(stdout, key, info.key_size, " ");
 828                                 printf("\n\nNot found\n");
 829                         }
 830                 } else {
 831                         p_err("lookup failed: %s", strerror(errno));
 832                 }
 833
 834                 goto exit_free;
 835         }
 836
 837         /* here means bpf_map_lookup_elem() succeeded */
 838         err = get_btf(&info, &btf);
 839         if (err) {
 840                 p_err("failed to get btf");
 841                 goto exit_free;
 842         }
 843
 844         if (json_output) {
 845                 print_entry_json(&info, key, value, btf);
 846         } else if (btf) {
 847                 /* if here json_wtr wouldn't have been initialised,
 848                  * so let's create separate writer for btf
 849                  */
 850                 btf_wtr = get_btf_writer();
 851                 if (!btf_wtr) {
 852                         p_info("failed to create json writer for btf. falling back to plain output");
 853                         btf__free(btf);
 854                         btf = NULL;
 855                         print_entry_plain(&info, key, value);
 856                 } else {
 857                         struct btf_dumper d = {
 858                                 .btf = btf,
 859                                 .jw = btf_wtr,
 860                                 .is_plain_text = true,
 861                         };
 862
 863                         do_dump_btf(&d, &info, key, value);
 864                         jsonw_destroy(&btf_wtr);
 865                 }
 866         } else {
 867                 print_entry_plain(&info, key, value);
 868         }
 869
 870 exit_free:
 871         free(key);
 872         free(value);
 873         close(fd);
 874         btf__free(btf);
 875
 876         return err;
 877 }
 878
 879 static int do_getnext(int argc, char **argv)
 880 {
 881         struct bpf_map_info info = {};
 882         __u32 len = sizeof(info);
 883         void *key, *nextkey;
 884         int err;
 885         int fd;
 886
 887         if (argc < 2)
 888                 usage();
 889
 890         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 891         if (fd < 0)
 892                 return -1;
 893
 894         key = malloc(info.key_size);
 895         nextkey = malloc(info.key_size);
 896         if (!key || !nextkey) {
 897                 p_err("mem alloc failed");
 898                 err = -1;
 899                 goto exit_free;
 900         }
 901
 902         if (argc) {
 903                 err = parse_elem(argv, &info, key, NULL, info.key_size, 0,
 904                                  NULL, NULL);
 905                 if (err)
 906                         goto exit_free;
 907         } else {
 908                 free(key);
 909                 key = NULL;
 910         }
 911
 912         err = bpf_map_get_next_key(fd, key, nextkey);
 913         if (err) {
 914                 p_err("can't get next key: %s", strerror(errno));
 915                 goto exit_free;
 916         }
 917
 918         if (json_output) {
 919                 jsonw_start_object(json_wtr);
 920                 if (key) {
 921                         jsonw_name(json_wtr, "key");
 922                         print_hex_data_json(key, info.key_size);
 923                 } else {
 924                         jsonw_null_field(json_wtr, "key");
 925                 }
 926                 jsonw_name(json_wtr, "next_key");
 927                 print_hex_data_json(nextkey, info.key_size);
 928                 jsonw_end_object(json_wtr);
 929         } else {
 930                 if (key) {
 931                         printf("key:\n");
 932                         fprint_hex(stdout, key, info.key_size, " ");
 933                         printf("\n");
 934                 } else {
 935                         printf("key: None\n");
 936                 }
 937                 printf("next key:\n");
 938                 fprint_hex(stdout, nextkey, info.key_size, " ");
 939                 printf("\n");
 940         }
 941
 942 exit_free:
 943         free(nextkey);
 944         free(key);
 945         close(fd);
 946
 947         return err;
 948 }
 949
 950 static int do_delete(int argc, char **argv)
 951 {
 952         struct bpf_map_info info = {};
 953         __u32 len = sizeof(info);
 954         void *key;
 955         int err;
 956         int fd;
 957
 958         if (argc < 2)
 959                 usage();
 960
 961         fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
 962         if (fd < 0)
 963                 return -1;
 964
 965         key = malloc(info.key_size);
 966         if (!key) {
 967                 p_err("mem alloc failed");
 968                 err = -1;
 969                 goto exit_free;
 970         }
 971
 972         err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
 973         if (err)
 974                 goto exit_free;
 975
 976         err = bpf_map_delete_elem(fd, key);
 977         if (err)
 978                 p_err("delete failed: %s", strerror(errno));
 979
 980 exit_free:
 981         free(key);
 982         close(fd);
 983
 984         if (!err && json_output)
 985                 jsonw_null(json_wtr);
 986         return err;
 987 }
 988
 989 static int do_pin(int argc, char **argv)
 990 {
 991         int err;
 992
 993         err = do_pin_any(argc, argv, bpf_map_get_fd_by_id);
 994         if (!err && json_output)
 995                 jsonw_null(json_wtr);
 996         return err;
 997 }
 998
 999 static int do_help(int argc, char **argv)
1000 {
1001         if (json_output) {
1002                 jsonw_null(json_wtr);
1003                 return 0;
1004         }
1005
1006         fprintf(stderr,
1007                 "Usage: %s %s { show | list }   [MAP]\n"
1008                 "       %s %s dump       MAP\n"
1009                 "       %s %s update     MAP  key DATA value VALUE [UPDATE_FLAGS]\n"
1010                 "       %s %s lookup     MAP  key DATA\n"
1011                 "       %s %s getnext    MAP [key DATA]\n"
1012                 "       %s %s delete     MAP  key DATA\n"
1013                 "       %s %s pin        MAP  FILE\n"
1014                 "       %s %s event_pipe MAP [cpu N index M]\n"
1015                 "       %s %s help\n"
1016                 "\n"
1017                 "       " HELP_SPEC_MAP "\n"
1018                 "       DATA := { [hex] BYTES }\n"
1019                 "       " HELP_SPEC_PROGRAM "\n"
1020                 "       VALUE := { DATA | MAP | PROG }\n"
1021                 "       UPDATE_FLAGS := { any | exist | noexist }\n"
1022                 "       " HELP_SPEC_OPTIONS "\n"
1023                 "",
1024                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
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
1028         return 0;
1029 }
1030
1031 static const struct cmd cmds[] = {
1032         { "show",       do_show },
1033         { "list",       do_show },
1034         { "help",       do_help },
1035         { "dump",       do_dump },
1036         { "update",     do_update },
1037         { "lookup",     do_lookup },
1038         { "getnext",    do_getnext },
1039         { "delete",     do_delete },
1040         { "pin",        do_pin },
1041         { "event_pipe", do_event_pipe },
1042         { 0 }
1043 };
1044
1045 int do_map(int argc, char **argv)
1046 {
1047         return cmd_select(cmds, argc, argv, do_help);
1048 }