tools/bpf/bpftool/prog.c

   1 /*
   2  * Copyright (C) 2017 Netronome Systems, Inc.
   3  *
   4  * This software is dual licensed under the GNU General License Version 2,
   5  * June 1991 as shown in the file COPYING in the top-level directory of this
   6  * source tree or the BSD 2-Clause License provided below.  You have the
   7  * option to license this software under the complete terms of either license.
   8  *
   9  * The BSD 2-Clause License:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      1. Redistributions of source code must retain the above
  16  *         copyright notice, this list of conditions and the following
  17  *         disclaimer.
  18  *
  19  *      2. Redistributions in binary form must reproduce the above
  20  *         copyright notice, this list of conditions and the following
  21  *         disclaimer in the documentation and/or other materials
  22  *         provided with the distribution.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33
  34 /* Author: Jakub Kicinski <kubakici@wp.pl> */
  35
  36 #include <errno.h>
  37 #include <fcntl.h>
  38 #include <stdarg.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <time.h>
  43 #include <unistd.h>
  44 #include <sys/types.h>
  45 #include <sys/stat.h>
  46
  47 #include <bpf.h>
  48 #include <libbpf.h>
  49
  50 #include "main.h"
  51 #include "disasm.h"
  52
  53 static const char * const prog_type_name[] = {
  54         [BPF_PROG_TYPE_UNSPEC]          = "unspec",
  55         [BPF_PROG_TYPE_SOCKET_FILTER]   = "socket_filter",
  56         [BPF_PROG_TYPE_KPROBE]          = "kprobe",
  57         [BPF_PROG_TYPE_SCHED_CLS]       = "sched_cls",
  58         [BPF_PROG_TYPE_SCHED_ACT]       = "sched_act",
  59         [BPF_PROG_TYPE_TRACEPOINT]      = "tracepoint",
  60         [BPF_PROG_TYPE_XDP]             = "xdp",
  61         [BPF_PROG_TYPE_PERF_EVENT]      = "perf_event",
  62         [BPF_PROG_TYPE_CGROUP_SKB]      = "cgroup_skb",
  63         [BPF_PROG_TYPE_CGROUP_SOCK]     = "cgroup_sock",
  64         [BPF_PROG_TYPE_LWT_IN]          = "lwt_in",
  65         [BPF_PROG_TYPE_LWT_OUT]         = "lwt_out",
  66         [BPF_PROG_TYPE_LWT_XMIT]        = "lwt_xmit",
  67         [BPF_PROG_TYPE_SOCK_OPS]        = "sock_ops",
  68         [BPF_PROG_TYPE_SK_SKB]          = "sk_skb",
  69 };
  70
  71 static void print_boot_time(__u64 nsecs, char *buf, unsigned int size)
  72 {
  73         struct timespec real_time_ts, boot_time_ts;
  74         time_t wallclock_secs;
  75         struct tm load_tm;
  76
  77         buf[--size] = '\0';
  78
  79         if (clock_gettime(CLOCK_REALTIME, &real_time_ts) ||
  80             clock_gettime(CLOCK_BOOTTIME, &boot_time_ts)) {
  81                 perror("Can't read clocks");
  82                 snprintf(buf, size, "%llu", nsecs / 1000000000);
  83                 return;
  84         }
  85
  86         wallclock_secs = (real_time_ts.tv_sec - boot_time_ts.tv_sec) +
  87                 nsecs / 1000000000;
  88
  89         if (!localtime_r(&wallclock_secs, &load_tm)) {
  90                 snprintf(buf, size, "%llu", nsecs / 1000000000);
  91                 return;
  92         }
  93
  94         strftime(buf, size, "%b %d/%H:%M", &load_tm);
  95 }
  96
  97 static int prog_fd_by_tag(unsigned char *tag)
  98 {
  99         struct bpf_prog_info info = {};
 100         __u32 len = sizeof(info);
 101         unsigned int id = 0;
 102         int err;
 103         int fd;
 104
 105         while (true) {
 106                 err = bpf_prog_get_next_id(id, &id);
 107                 if (err) {
 108                         p_err("%s", strerror(errno));
 109                         return -1;
 110                 }
 111
 112                 fd = bpf_prog_get_fd_by_id(id);
 113                 if (fd < 0) {
 114                         p_err("can't get prog by id (%u): %s",
 115                               id, strerror(errno));
 116                         return -1;
 117                 }
 118
 119                 err = bpf_obj_get_info_by_fd(fd, &info, &len);
 120                 if (err) {
 121                         p_err("can't get prog info (%u): %s",
 122                               id, strerror(errno));
 123                         close(fd);
 124                         return -1;
 125                 }
 126
 127                 if (!memcmp(tag, info.tag, BPF_TAG_SIZE))
 128                         return fd;
 129
 130                 close(fd);
 131         }
 132 }
 133
 134 int prog_parse_fd(int *argc, char ***argv)
 135 {
 136         int fd;
 137
 138         if (is_prefix(**argv, "id")) {
 139                 unsigned int id;
 140                 char *endptr;
 141
 142                 NEXT_ARGP();
 143
 144                 id = strtoul(**argv, &endptr, 0);
 145                 if (*endptr) {
 146                         p_err("can't parse %s as ID", **argv);
 147                         return -1;
 148                 }
 149                 NEXT_ARGP();
 150
 151                 fd = bpf_prog_get_fd_by_id(id);
 152                 if (fd < 0)
 153                         p_err("get by id (%u): %s", id, strerror(errno));
 154                 return fd;
 155         } else if (is_prefix(**argv, "tag")) {
 156                 unsigned char tag[BPF_TAG_SIZE];
 157
 158                 NEXT_ARGP();
 159
 160                 if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2,
 161                            tag + 3, tag + 4, tag + 5, tag + 6, tag + 7)
 162                     != BPF_TAG_SIZE) {
 163                         p_err("can't parse tag");
 164                         return -1;
 165                 }
 166                 NEXT_ARGP();
 167
 168                 return prog_fd_by_tag(tag);
 169         } else if (is_prefix(**argv, "pinned")) {
 170                 char *path;
 171
 172                 NEXT_ARGP();
 173
 174                 path = **argv;
 175                 NEXT_ARGP();
 176
 177                 return open_obj_pinned_any(path, BPF_OBJ_PROG);
 178         }
 179
 180         p_err("expected 'id', 'tag' or 'pinned', got: '%s'?", **argv);
 181         return -1;
 182 }
 183
 184 static void show_prog_maps(int fd, u32 num_maps)
 185 {
 186         struct bpf_prog_info info = {};
 187         __u32 len = sizeof(info);
 188         __u32 map_ids[num_maps];
 189         unsigned int i;
 190         int err;
 191
 192         info.nr_map_ids = num_maps;
 193         info.map_ids = ptr_to_u64(map_ids);
 194
 195         err = bpf_obj_get_info_by_fd(fd, &info, &len);
 196         if (err || !info.nr_map_ids)
 197                 return;
 198
 199         if (json_output) {
 200                 jsonw_name(json_wtr, "map_ids");
 201                 jsonw_start_array(json_wtr);
 202                 for (i = 0; i < info.nr_map_ids; i++)
 203                         jsonw_uint(json_wtr, map_ids[i]);
 204                 jsonw_end_array(json_wtr);
 205         } else {
 206                 printf("  map_ids ");
 207                 for (i = 0; i < info.nr_map_ids; i++)
 208                         printf("%u%s", map_ids[i],
 209                                i == info.nr_map_ids - 1 ? "" : ",");
 210         }
 211 }
 212
 213 static void print_prog_json(struct bpf_prog_info *info, int fd)
 214 {
 215         char *memlock;
 216
 217         jsonw_start_object(json_wtr);
 218         jsonw_uint_field(json_wtr, "id", info->id);
 219         if (info->type < ARRAY_SIZE(prog_type_name))
 220                 jsonw_string_field(json_wtr, "type",
 221                                    prog_type_name[info->type]);
 222         else
 223                 jsonw_uint_field(json_wtr, "type", info->type);
 224
 225         if (*info->name)
 226                 jsonw_string_field(json_wtr, "name", info->name);
 227
 228         jsonw_name(json_wtr, "tag");
 229         jsonw_printf(json_wtr, "\"" BPF_TAG_FMT "\"",
 230                      info->tag[0], info->tag[1], info->tag[2], info->tag[3],
 231                      info->tag[4], info->tag[5], info->tag[6], info->tag[7]);
 232
 233         if (info->load_time) {
 234                 char buf[32];
 235
 236                 print_boot_time(info->load_time, buf, sizeof(buf));
 237
 238                 /* Piggy back on load_time, since 0 uid is a valid one */
 239                 jsonw_string_field(json_wtr, "loaded_at", buf);
 240                 jsonw_uint_field(json_wtr, "uid", info->created_by_uid);
 241         }
 242
 243         jsonw_uint_field(json_wtr, "bytes_xlated", info->xlated_prog_len);
 244
 245         if (info->jited_prog_len) {
 246                 jsonw_bool_field(json_wtr, "jited", true);
 247                 jsonw_uint_field(json_wtr, "bytes_jited", info->jited_prog_len);
 248         } else {
 249                 jsonw_bool_field(json_wtr, "jited", false);
 250         }
 251
 252         memlock = get_fdinfo(fd, "memlock");
 253         if (memlock)
 254                 jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
 255         free(memlock);
 256
 257         if (info->nr_map_ids)
 258                 show_prog_maps(fd, info->nr_map_ids);
 259
 260         if (!hash_empty(prog_table.table)) {
 261                 struct pinned_obj *obj;
 262
 263                 jsonw_name(json_wtr, "pinned");
 264                 jsonw_start_array(json_wtr);
 265                 hash_for_each_possible(prog_table.table, obj, hash, info->id) {
 266                         if (obj->id == info->id)
 267                                 jsonw_string(json_wtr, obj->path);
 268                 }
 269                 jsonw_end_array(json_wtr);
 270         }
 271
 272         jsonw_end_object(json_wtr);
 273 }
 274
 275 static void print_prog_plain(struct bpf_prog_info *info, int fd)
 276 {
 277         char *memlock;
 278
 279         printf("%u: ", info->id);
 280         if (info->type < ARRAY_SIZE(prog_type_name))
 281                 printf("%s  ", prog_type_name[info->type]);
 282         else
 283                 printf("type %u  ", info->type);
 284
 285         if (*info->name)
 286                 printf("name %s  ", info->name);
 287
 288         printf("tag ");
 289         fprint_hex(stdout, info->tag, BPF_TAG_SIZE, "");
 290         printf("\n");
 291
 292         if (info->load_time) {
 293                 char buf[32];
 294
 295                 print_boot_time(info->load_time, buf, sizeof(buf));
 296
 297                 /* Piggy back on load_time, since 0 uid is a valid one */
 298                 printf("\tloaded_at %s  uid %u\n", buf, info->created_by_uid);
 299         }
 300
 301         printf("\txlated %uB", info->xlated_prog_len);
 302
 303         if (info->jited_prog_len)
 304                 printf("  jited %uB", info->jited_prog_len);
 305         else
 306                 printf("  not jited");
 307
 308         memlock = get_fdinfo(fd, "memlock");
 309         if (memlock)
 310                 printf("  memlock %sB", memlock);
 311         free(memlock);
 312
 313         if (info->nr_map_ids)
 314                 show_prog_maps(fd, info->nr_map_ids);
 315
 316         if (!hash_empty(prog_table.table)) {
 317                 struct pinned_obj *obj;
 318
 319                 printf("\n");
 320                 hash_for_each_possible(prog_table.table, obj, hash, info->id) {
 321                         if (obj->id == info->id)
 322                                 printf("\tpinned %s\n", obj->path);
 323                 }
 324         }
 325
 326         printf("\n");
 327 }
 328
 329 static int show_prog(int fd)
 330 {
 331         struct bpf_prog_info info = {};
 332         __u32 len = sizeof(info);
 333         int err;
 334
 335         err = bpf_obj_get_info_by_fd(fd, &info, &len);
 336         if (err) {
 337                 p_err("can't get prog info: %s", strerror(errno));
 338                 return -1;
 339         }
 340
 341         if (json_output)
 342                 print_prog_json(&info, fd);
 343         else
 344                 print_prog_plain(&info, fd);
 345
 346         return 0;
 347 }
 348
 349 static int do_show(int argc, char **argv)
 350 {
 351         __u32 id = 0;
 352         int err;
 353         int fd;
 354
 355         if (show_pinned)
 356                 build_pinned_obj_table(&prog_table, BPF_OBJ_PROG);
 357
 358         if (argc == 2) {
 359                 fd = prog_parse_fd(&argc, &argv);
 360                 if (fd < 0)
 361                         return -1;
 362
 363                 return show_prog(fd);
 364         }
 365
 366         if (argc)
 367                 return BAD_ARG();
 368
 369         if (json_output)
 370                 jsonw_start_array(json_wtr);
 371         while (true) {
 372                 err = bpf_prog_get_next_id(id, &id);
 373                 if (err) {
 374                         if (errno == ENOENT) {
 375                                 err = 0;
 376                                 break;
 377                         }
 378                         p_err("can't get next program: %s%s", strerror(errno),
 379                               errno == EINVAL ? " -- kernel too old?" : "");
 380                         err = -1;
 381                         break;
 382                 }
 383
 384                 fd = bpf_prog_get_fd_by_id(id);
 385                 if (fd < 0) {
 386                         p_err("can't get prog by id (%u): %s",
 387                               id, strerror(errno));
 388                         err = -1;
 389                         break;
 390                 }
 391
 392                 err = show_prog(fd);
 393                 close(fd);
 394                 if (err)
 395                         break;
 396         }
 397
 398         if (json_output)
 399                 jsonw_end_array(json_wtr);
 400
 401         return err;
 402 }
 403
 404 static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...)
 405 {
 406         va_list args;
 407
 408         va_start(args, fmt);
 409         vprintf(fmt, args);
 410         va_end(args);
 411 }
 412
 413 static void dump_xlated_plain(void *buf, unsigned int len, bool opcodes)
 414 {
 415         struct bpf_insn *insn = buf;
 416         bool double_insn = false;
 417         unsigned int i;
 418
 419         for (i = 0; i < len / sizeof(*insn); i++) {
 420                 if (double_insn) {
 421                         double_insn = false;
 422                         continue;
 423                 }
 424
 425                 double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
 426
 427                 printf("% 4d: ", i);
 428                 print_bpf_insn(print_insn, NULL, insn + i, true);
 429
 430                 if (opcodes) {
 431                         printf("       ");
 432                         fprint_hex(stdout, insn + i, 8, " ");
 433                         if (double_insn && i < len - 1) {
 434                                 printf(" ");
 435                                 fprint_hex(stdout, insn + i + 1, 8, " ");
 436                         }
 437                         printf("\n");
 438                 }
 439         }
 440 }
 441
 442 static void print_insn_json(struct bpf_verifier_env *env, const char *fmt, ...)
 443 {
 444         unsigned int l = strlen(fmt);
 445         char chomped_fmt[l];
 446         va_list args;
 447
 448         va_start(args, fmt);
 449         if (l > 0) {
 450                 strncpy(chomped_fmt, fmt, l - 1);
 451                 chomped_fmt[l - 1] = '\0';
 452         }
 453         jsonw_vprintf_enquote(json_wtr, chomped_fmt, args);
 454         va_end(args);
 455 }
 456
 457 static void dump_xlated_json(void *buf, unsigned int len, bool opcodes)
 458 {
 459         struct bpf_insn *insn = buf;
 460         bool double_insn = false;
 461         unsigned int i;
 462
 463         jsonw_start_array(json_wtr);
 464         for (i = 0; i < len / sizeof(*insn); i++) {
 465                 if (double_insn) {
 466                         double_insn = false;
 467                         continue;
 468                 }
 469                 double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
 470
 471                 jsonw_start_object(json_wtr);
 472                 jsonw_name(json_wtr, "disasm");
 473                 print_bpf_insn(print_insn_json, NULL, insn + i, true);
 474
 475                 if (opcodes) {
 476                         jsonw_name(json_wtr, "opcodes");
 477                         jsonw_start_object(json_wtr);
 478
 479                         jsonw_name(json_wtr, "code");
 480                         jsonw_printf(json_wtr, "\"0x%02hhx\"", insn[i].code);
 481
 482                         jsonw_name(json_wtr, "src_reg");
 483                         jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].src_reg);
 484
 485                         jsonw_name(json_wtr, "dst_reg");
 486                         jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].dst_reg);
 487
 488                         jsonw_name(json_wtr, "off");
 489                         print_hex_data_json((uint8_t *)(&insn[i].off), 2);
 490
 491                         jsonw_name(json_wtr, "imm");
 492                         if (double_insn && i < len - 1)
 493                                 print_hex_data_json((uint8_t *)(&insn[i].imm),
 494                                                     12);
 495                         else
 496                                 print_hex_data_json((uint8_t *)(&insn[i].imm),
 497                                                     4);
 498                         jsonw_end_object(json_wtr);
 499                 }
 500                 jsonw_end_object(json_wtr);
 501         }
 502         jsonw_end_array(json_wtr);
 503 }
 504
 505 static int do_dump(int argc, char **argv)
 506 {
 507         struct bpf_prog_info info = {};
 508         __u32 len = sizeof(info);
 509         unsigned int buf_size;
 510         char *filepath = NULL;
 511         bool opcodes = false;
 512         unsigned char *buf;
 513         __u32 *member_len;
 514         __u64 *member_ptr;
 515         ssize_t n;
 516         int err;
 517         int fd;
 518
 519         if (is_prefix(*argv, "jited")) {
 520                 member_len = &info.jited_prog_len;
 521                 member_ptr = &info.jited_prog_insns;
 522         } else if (is_prefix(*argv, "xlated")) {
 523                 member_len = &info.xlated_prog_len;
 524                 member_ptr = &info.xlated_prog_insns;
 525         } else {
 526                 p_err("expected 'xlated' or 'jited', got: %s", *argv);
 527                 return -1;
 528         }
 529         NEXT_ARG();
 530
 531         if (argc < 2)
 532                 usage();
 533
 534         fd = prog_parse_fd(&argc, &argv);
 535         if (fd < 0)
 536                 return -1;
 537
 538         if (is_prefix(*argv, "file")) {
 539                 NEXT_ARG();
 540                 if (!argc) {
 541                         p_err("expected file path");
 542                         return -1;
 543                 }
 544
 545                 filepath = *argv;
 546                 NEXT_ARG();
 547         } else if (is_prefix(*argv, "opcodes")) {
 548                 opcodes = true;
 549                 NEXT_ARG();
 550         }
 551
 552         if (argc) {
 553                 usage();
 554                 return -1;
 555         }
 556
 557         err = bpf_obj_get_info_by_fd(fd, &info, &len);
 558         if (err) {
 559                 p_err("can't get prog info: %s", strerror(errno));
 560                 return -1;
 561         }
 562
 563         if (!*member_len) {
 564                 p_info("no instructions returned");
 565                 close(fd);
 566                 return 0;
 567         }
 568
 569         buf_size = *member_len;
 570
 571         buf = malloc(buf_size);
 572         if (!buf) {
 573                 p_err("mem alloc failed");
 574                 close(fd);
 575                 return -1;
 576         }
 577
 578         memset(&info, 0, sizeof(info));
 579
 580         *member_ptr = ptr_to_u64(buf);
 581         *member_len = buf_size;
 582
 583         err = bpf_obj_get_info_by_fd(fd, &info, &len);
 584         close(fd);
 585         if (err) {
 586                 p_err("can't get prog info: %s", strerror(errno));
 587                 goto err_free;
 588         }
 589
 590         if (*member_len > buf_size) {
 591                 p_err("too many instructions returned");
 592                 goto err_free;
 593         }
 594
 595         if (filepath) {
 596                 fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 597                 if (fd < 0) {
 598                         p_err("can't open file %s: %s", filepath,
 599                               strerror(errno));
 600                         goto err_free;
 601                 }
 602
 603                 n = write(fd, buf, *member_len);
 604                 close(fd);
 605                 if (n != *member_len) {
 606                         p_err("error writing output file: %s",
 607                               n < 0 ? strerror(errno) : "short write");
 608                         goto err_free;
 609                 }
 610         } else {
 611                 if (member_len == &info.jited_prog_len)
 612                         disasm_print_insn(buf, *member_len, opcodes);
 613                 else
 614                         if (json_output)
 615                                 dump_xlated_json(buf, *member_len, opcodes);
 616                         else
 617                                 dump_xlated_plain(buf, *member_len, opcodes);
 618         }
 619
 620         free(buf);
 621
 622         return 0;
 623
 624 err_free:
 625         free(buf);
 626         return -1;
 627 }
 628
 629 static int do_pin(int argc, char **argv)
 630 {
 631         int err;
 632
 633         err = do_pin_any(argc, argv, bpf_prog_get_fd_by_id);
 634         if (!err && json_output)
 635                 jsonw_null(json_wtr);
 636         return err;
 637 }
 638
 639 static int do_load(int argc, char **argv)
 640 {
 641         struct bpf_object *obj;
 642         int prog_fd;
 643
 644         if (argc != 2)
 645                 usage();
 646
 647         if (bpf_prog_load(argv[0], BPF_PROG_TYPE_UNSPEC, &obj, &prog_fd)) {
 648                 p_err("failed to load program\n");
 649                 return -1;
 650         }
 651
 652         if (do_pin_fd(prog_fd, argv[1])) {
 653                 p_err("failed to pin program\n");
 654                 return -1;
 655         }
 656
 657         if (json_output)
 658                 jsonw_null(json_wtr);
 659
 660         return 0;
 661 }
 662
 663 static int do_help(int argc, char **argv)
 664 {
 665         if (json_output) {
 666                 jsonw_null(json_wtr);
 667                 return 0;
 668         }
 669
 670         fprintf(stderr,
 671                 "Usage: %s %s show [PROG]\n"
 672                 "       %s %s dump xlated PROG [{ file FILE | opcodes }]\n"
 673                 "       %s %s dump jited  PROG [{ file FILE | opcodes }]\n"
 674                 "       %s %s pin   PROG FILE\n"
 675                 "       %s %s load  OBJ  FILE\n"
 676                 "       %s %s help\n"
 677                 "\n"
 678                 "       " HELP_SPEC_PROGRAM "\n"
 679                 "       " HELP_SPEC_OPTIONS "\n"
 680                 "",
 681                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
 682                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]);
 683
 684         return 0;
 685 }
 686
 687 static const struct cmd cmds[] = {
 688         { "show",       do_show },
 689         { "help",       do_help },
 690         { "dump",       do_dump },
 691         { "pin",        do_pin },
 692         { "load",       do_load },
 693         { 0 }
 694 };
 695
 696 int do_prog(int argc, char **argv)
 697 {
 698         return cmd_select(cmds, argc, argv, do_help);
 699 }