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 <net/if.h>
  45 #include <sys/types.h>
  46 #include <sys/stat.h>
  47
  48 #include <bpf.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->status & BPF_PROG_STATUS_DEV_BOUND) {
 234                 jsonw_name(json_wtr, "dev");
 235                 if (info->ifindex) {
 236                         char name[IF_NAMESIZE];
 237
 238                         if (!if_indextoname(info->ifindex, name))
 239                                 jsonw_printf(json_wtr, "\"ifindex:%d\"",
 240                                              info->ifindex);
 241                         else
 242                                 jsonw_printf(json_wtr, "\"%s\"", name);
 243                 } else {
 244                         jsonw_printf(json_wtr, "\"unknown\"");
 245                 }
 246         }
 247
 248         if (info->load_time) {
 249                 char buf[32];
 250
 251                 print_boot_time(info->load_time, buf, sizeof(buf));
 252
 253                 /* Piggy back on load_time, since 0 uid is a valid one */
 254                 jsonw_string_field(json_wtr, "loaded_at", buf);
 255                 jsonw_uint_field(json_wtr, "uid", info->created_by_uid);
 256         }
 257
 258         jsonw_uint_field(json_wtr, "bytes_xlated", info->xlated_prog_len);
 259
 260         if (info->jited_prog_len) {
 261                 jsonw_bool_field(json_wtr, "jited", true);
 262                 jsonw_uint_field(json_wtr, "bytes_jited", info->jited_prog_len);
 263         } else {
 264                 jsonw_bool_field(json_wtr, "jited", false);
 265         }
 266
 267         memlock = get_fdinfo(fd, "memlock");
 268         if (memlock)
 269                 jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
 270         free(memlock);
 271
 272         if (info->nr_map_ids)
 273                 show_prog_maps(fd, info->nr_map_ids);
 274
 275         jsonw_end_object(json_wtr);
 276 }
 277
 278 static void print_prog_plain(struct bpf_prog_info *info, int fd)
 279 {
 280         char *memlock;
 281
 282         printf("%u: ", info->id);
 283         if (info->type < ARRAY_SIZE(prog_type_name))
 284                 printf("%s  ", prog_type_name[info->type]);
 285         else
 286                 printf("type %u  ", info->type);
 287
 288         if (*info->name)
 289                 printf("name %s  ", info->name);
 290
 291         printf("tag ");
 292         fprint_hex(stdout, info->tag, BPF_TAG_SIZE, "");
 293         printf(" ");
 294
 295         if (info->status & BPF_PROG_STATUS_DEV_BOUND) {
 296                 printf("dev ");
 297                 if (info->ifindex) {
 298                         char name[IF_NAMESIZE];
 299
 300                         if (!if_indextoname(info->ifindex, name))
 301                                 printf("ifindex:%d ", info->ifindex);
 302                         else
 303                                 printf("%s ", name);
 304                 } else {
 305                         printf("unknown ");
 306                 }
 307         }
 308         printf("\n");
 309
 310         if (info->load_time) {
 311                 char buf[32];
 312
 313                 print_boot_time(info->load_time, buf, sizeof(buf));
 314
 315                 /* Piggy back on load_time, since 0 uid is a valid one */
 316                 printf("\tloaded_at %s  uid %u\n", buf, info->created_by_uid);
 317         }
 318
 319         printf("\txlated %uB", info->xlated_prog_len);
 320
 321         if (info->jited_prog_len)
 322                 printf("  jited %uB", info->jited_prog_len);
 323         else
 324                 printf("  not jited");
 325
 326         memlock = get_fdinfo(fd, "memlock");
 327         if (memlock)
 328                 printf("  memlock %sB", memlock);
 329         free(memlock);
 330
 331         if (info->nr_map_ids)
 332                 show_prog_maps(fd, info->nr_map_ids);
 333
 334         printf("\n");
 335 }
 336
 337 static int show_prog(int fd)
 338 {
 339         struct bpf_prog_info info = {};
 340         __u32 len = sizeof(info);
 341         int err;
 342
 343         err = bpf_obj_get_info_by_fd(fd, &info, &len);
 344         if (err) {
 345                 p_err("can't get prog info: %s", strerror(errno));
 346                 return -1;
 347         }
 348
 349         if (json_output)
 350                 print_prog_json(&info, fd);
 351         else
 352                 print_prog_plain(&info, fd);
 353
 354         return 0;
 355 }
 356
 357 static int do_show(int argc, char **argv)
 358 {
 359         __u32 id = 0;
 360         int err;
 361         int fd;
 362
 363         if (argc == 2) {
 364                 fd = prog_parse_fd(&argc, &argv);
 365                 if (fd < 0)
 366                         return -1;
 367
 368                 return show_prog(fd);
 369         }
 370
 371         if (argc)
 372                 return BAD_ARG();
 373
 374         if (json_output)
 375                 jsonw_start_array(json_wtr);
 376         while (true) {
 377                 err = bpf_prog_get_next_id(id, &id);
 378                 if (err) {
 379                         if (errno == ENOENT) {
 380                                 err = 0;
 381                                 break;
 382                         }
 383                         p_err("can't get next program: %s%s", strerror(errno),
 384                               errno == EINVAL ? " -- kernel too old?" : "");
 385                         err = -1;
 386                         break;
 387                 }
 388
 389                 fd = bpf_prog_get_fd_by_id(id);
 390                 if (fd < 0) {
 391                         p_err("can't get prog by id (%u): %s",
 392                               id, strerror(errno));
 393                         err = -1;
 394                         break;
 395                 }
 396
 397                 err = show_prog(fd);
 398                 close(fd);
 399                 if (err)
 400                         break;
 401         }
 402
 403         if (json_output)
 404                 jsonw_end_array(json_wtr);
 405
 406         return err;
 407 }
 408
 409 static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...)
 410 {
 411         va_list args;
 412
 413         va_start(args, fmt);
 414         vprintf(fmt, args);
 415         va_end(args);
 416 }
 417
 418 static void dump_xlated_plain(void *buf, unsigned int len, bool opcodes)
 419 {
 420         struct bpf_insn *insn = buf;
 421         bool double_insn = false;
 422         unsigned int i;
 423
 424         for (i = 0; i < len / sizeof(*insn); i++) {
 425                 if (double_insn) {
 426                         double_insn = false;
 427                         continue;
 428                 }
 429
 430                 double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
 431
 432                 printf("% 4d: ", i);
 433                 print_bpf_insn(print_insn, NULL, insn + i, true);
 434
 435                 if (opcodes) {
 436                         printf("       ");
 437                         fprint_hex(stdout, insn + i, 8, " ");
 438                         if (double_insn && i < len - 1) {
 439                                 printf(" ");
 440                                 fprint_hex(stdout, insn + i + 1, 8, " ");
 441                         }
 442                         printf("\n");
 443                 }
 444         }
 445 }
 446
 447 static void print_insn_json(struct bpf_verifier_env *env, const char *fmt, ...)
 448 {
 449         unsigned int l = strlen(fmt);
 450         char chomped_fmt[l];
 451         va_list args;
 452
 453         va_start(args, fmt);
 454         if (l > 0) {
 455                 strncpy(chomped_fmt, fmt, l - 1);
 456                 chomped_fmt[l - 1] = '\0';
 457         }
 458         jsonw_vprintf_enquote(json_wtr, chomped_fmt, args);
 459         va_end(args);
 460 }
 461
 462 static void dump_xlated_json(void *buf, unsigned int len, bool opcodes)
 463 {
 464         struct bpf_insn *insn = buf;
 465         bool double_insn = false;
 466         unsigned int i;
 467
 468         jsonw_start_array(json_wtr);
 469         for (i = 0; i < len / sizeof(*insn); i++) {
 470                 if (double_insn) {
 471                         double_insn = false;
 472                         continue;
 473                 }
 474                 double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
 475
 476                 jsonw_start_object(json_wtr);
 477                 jsonw_name(json_wtr, "disasm");
 478                 print_bpf_insn(print_insn_json, NULL, insn + i, true);
 479
 480                 if (opcodes) {
 481                         jsonw_name(json_wtr, "opcodes");
 482                         jsonw_start_object(json_wtr);
 483
 484                         jsonw_name(json_wtr, "code");
 485                         jsonw_printf(json_wtr, "\"0x%02hhx\"", insn[i].code);
 486
 487                         jsonw_name(json_wtr, "src_reg");
 488                         jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].src_reg);
 489
 490                         jsonw_name(json_wtr, "dst_reg");
 491                         jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].dst_reg);
 492
 493                         jsonw_name(json_wtr, "off");
 494                         print_hex_data_json((uint8_t *)(&insn[i].off), 2);
 495
 496                         jsonw_name(json_wtr, "imm");
 497                         if (double_insn && i < len - 1)
 498                                 print_hex_data_json((uint8_t *)(&insn[i].imm),
 499                                                     12);
 500                         else
 501                                 print_hex_data_json((uint8_t *)(&insn[i].imm),
 502                                                     4);
 503                         jsonw_end_object(json_wtr);
 504                 }
 505                 jsonw_end_object(json_wtr);
 506         }
 507         jsonw_end_array(json_wtr);
 508 }
 509
 510 static int do_dump(int argc, char **argv)
 511 {
 512         struct bpf_prog_info info = {};
 513         __u32 len = sizeof(info);
 514         unsigned int buf_size;
 515         char *filepath = NULL;
 516         bool opcodes = false;
 517         unsigned char *buf;
 518         __u32 *member_len;
 519         __u64 *member_ptr;
 520         ssize_t n;
 521         int err;
 522         int fd;
 523
 524         if (is_prefix(*argv, "jited")) {
 525                 member_len = &info.jited_prog_len;
 526                 member_ptr = &info.jited_prog_insns;
 527         } else if (is_prefix(*argv, "xlated")) {
 528                 member_len = &info.xlated_prog_len;
 529                 member_ptr = &info.xlated_prog_insns;
 530         } else {
 531                 p_err("expected 'xlated' or 'jited', got: %s", *argv);
 532                 return -1;
 533         }
 534         NEXT_ARG();
 535
 536         if (argc < 2)
 537                 usage();
 538
 539         fd = prog_parse_fd(&argc, &argv);
 540         if (fd < 0)
 541                 return -1;
 542
 543         if (is_prefix(*argv, "file")) {
 544                 NEXT_ARG();
 545                 if (!argc) {
 546                         p_err("expected file path");
 547                         return -1;
 548                 }
 549
 550                 filepath = *argv;
 551                 NEXT_ARG();
 552         } else if (is_prefix(*argv, "opcodes")) {
 553                 opcodes = true;
 554                 NEXT_ARG();
 555         }
 556
 557         if (argc) {
 558                 usage();
 559                 return -1;
 560         }
 561
 562         err = bpf_obj_get_info_by_fd(fd, &info, &len);
 563         if (err) {
 564                 p_err("can't get prog info: %s", strerror(errno));
 565                 return -1;
 566         }
 567
 568         if (!*member_len) {
 569                 p_info("no instructions returned");
 570                 close(fd);
 571                 return 0;
 572         }
 573
 574         buf_size = *member_len;
 575
 576         buf = malloc(buf_size);
 577         if (!buf) {
 578                 p_err("mem alloc failed");
 579                 close(fd);
 580                 return -1;
 581         }
 582
 583         memset(&info, 0, sizeof(info));
 584
 585         *member_ptr = ptr_to_u64(buf);
 586         *member_len = buf_size;
 587
 588         err = bpf_obj_get_info_by_fd(fd, &info, &len);
 589         close(fd);
 590         if (err) {
 591                 p_err("can't get prog info: %s", strerror(errno));
 592                 goto err_free;
 593         }
 594
 595         if (*member_len > buf_size) {
 596                 p_err("too many instructions returned");
 597                 goto err_free;
 598         }
 599
 600         if (filepath) {
 601                 fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 602                 if (fd < 0) {
 603                         p_err("can't open file %s: %s", filepath,
 604                               strerror(errno));
 605                         goto err_free;
 606                 }
 607
 608                 n = write(fd, buf, *member_len);
 609                 close(fd);
 610                 if (n != *member_len) {
 611                         p_err("error writing output file: %s",
 612                               n < 0 ? strerror(errno) : "short write");
 613                         goto err_free;
 614                 }
 615         } else {
 616                 if (member_len == &info.jited_prog_len)
 617                         disasm_print_insn(buf, *member_len, opcodes);
 618                 else
 619                         if (json_output)
 620                                 dump_xlated_json(buf, *member_len, opcodes);
 621                         else
 622                                 dump_xlated_plain(buf, *member_len, opcodes);
 623         }
 624
 625         free(buf);
 626
 627         return 0;
 628
 629 err_free:
 630         free(buf);
 631         return -1;
 632 }
 633
 634 static int do_pin(int argc, char **argv)
 635 {
 636         int err;
 637
 638         err = do_pin_any(argc, argv, bpf_prog_get_fd_by_id);
 639         if (!err && json_output)
 640                 jsonw_null(json_wtr);
 641         return err;
 642 }
 643
 644 static int do_help(int argc, char **argv)
 645 {
 646         if (json_output) {
 647                 jsonw_null(json_wtr);
 648                 return 0;
 649         }
 650
 651         fprintf(stderr,
 652                 "Usage: %s %s show [PROG]\n"
 653                 "       %s %s dump xlated PROG [{ file FILE | opcodes }]\n"
 654                 "       %s %s dump jited  PROG [{ file FILE | opcodes }]\n"
 655                 "       %s %s pin   PROG FILE\n"
 656                 "       %s %s help\n"
 657                 "\n"
 658                 "       " HELP_SPEC_PROGRAM "\n"
 659                 "       " HELP_SPEC_OPTIONS "\n"
 660                 "",
 661                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
 662                 bin_name, argv[-2], bin_name, argv[-2]);
 663
 664         return 0;
 665 }
 666
 667 static const struct cmd cmds[] = {
 668         { "show",       do_show },
 669         { "help",       do_help },
 670         { "dump",       do_dump },
 671         { "pin",        do_pin },
 672         { 0 }
 673 };
 674
 675 int do_prog(int argc, char **argv)
 676 {
 677         return cmd_select(cmds, argc, argv, do_help);
 678 }