tools/bpf/bpftool/main.c

   1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2 /* Copyright (C) 2017-2018 Netronome Systems, Inc. */
   3
   4 #include <ctype.h>
   5 #include <errno.h>
   6 #include <getopt.h>
   7 #include <linux/bpf.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11
  12 #include <bpf/bpf.h>
  13 #include <bpf/btf.h>
  14 #include <bpf/hashmap.h>
  15 #include <bpf/libbpf.h>
  16
  17 #include "main.h"
  18
  19 #define BATCH_LINE_LEN_MAX 65536
  20 #define BATCH_ARG_NB_MAX 4096
  21
  22 const char *bin_name;
  23 static int last_argc;
  24 static char **last_argv;
  25 static int (*last_do_help)(int argc, char **argv);
  26 json_writer_t *json_wtr;
  27 bool pretty_output;
  28 bool json_output;
  29 bool show_pinned;
  30 bool block_mount;
  31 bool verifier_logs;
  32 bool relaxed_maps;
  33 bool use_loader;
  34 struct btf *base_btf;
  35 struct hashmap *refs_table;
  36
  37 static void __noreturn clean_and_exit(int i)
  38 {
  39         if (json_output)
  40                 jsonw_destroy(&json_wtr);
  41
  42         exit(i);
  43 }
  44
  45 void usage(void)
  46 {
  47         last_do_help(last_argc - 1, last_argv + 1);
  48
  49         clean_and_exit(-1);
  50 }
  51
  52 static int do_help(int argc, char **argv)
  53 {
  54         if (json_output) {
  55                 jsonw_null(json_wtr);
  56                 return 0;
  57         }
  58
  59         fprintf(stderr,
  60                 "Usage: %s [OPTIONS] OBJECT { COMMAND | help }\n"
  61                 "       %s batch file FILE\n"
  62                 "       %s version\n"
  63                 "\n"
  64                 "       OBJECT := { prog | map | link | cgroup | perf | net | feature | btf | gen | struct_ops | iter }\n"
  65                 "       " HELP_SPEC_OPTIONS " |\n"
  66                 "                    {-V|--version} }\n"
  67                 "",
  68                 bin_name, bin_name, bin_name);
  69
  70         return 0;
  71 }
  72
  73 static int do_batch(int argc, char **argv);
  74 static int do_version(int argc, char **argv);
  75
  76 static const struct cmd commands[] = {
  77         { "help",       do_help },
  78         { "batch",      do_batch },
  79         { "prog",       do_prog },
  80         { "map",        do_map },
  81         { "link",       do_link },
  82         { "cgroup",     do_cgroup },
  83         { "perf",       do_perf },
  84         { "net",        do_net },
  85         { "feature",    do_feature },
  86         { "btf",        do_btf },
  87         { "gen",        do_gen },
  88         { "struct_ops", do_struct_ops },
  89         { "iter",       do_iter },
  90         { "version",    do_version },
  91         { 0 }
  92 };
  93
  94 #ifndef BPFTOOL_VERSION
  95 /* bpftool's major and minor version numbers are aligned on libbpf's. There is
  96  * an offset of 6 for the version number, because bpftool's version was higher
  97  * than libbpf's when we adopted this scheme. The patch number remains at 0
  98  * for now. Set BPFTOOL_VERSION to override.
  99  */
 100 #define BPFTOOL_MAJOR_VERSION (LIBBPF_MAJOR_VERSION + 6)
 101 #define BPFTOOL_MINOR_VERSION LIBBPF_MINOR_VERSION
 102 #define BPFTOOL_PATCH_VERSION 0
 103 #endif
 104
 105 static void
 106 print_feature(const char *feature, bool state, unsigned int *nb_features)
 107 {
 108         if (state) {
 109                 printf("%s %s", *nb_features ? "," : "", feature);
 110                 *nb_features = *nb_features + 1;
 111         }
 112 }
 113
 114 static int do_version(int argc, char **argv)
 115 {
 116 #ifdef HAVE_LIBBFD_SUPPORT
 117         const bool has_libbfd = true;
 118 #else
 119         const bool has_libbfd = false;
 120 #endif
 121 #ifdef HAVE_LLVM_SUPPORT
 122         const bool has_llvm = true;
 123 #else
 124         const bool has_llvm = false;
 125 #endif
 126 #ifdef BPFTOOL_WITHOUT_SKELETONS
 127         const bool has_skeletons = false;
 128 #else
 129         const bool has_skeletons = true;
 130 #endif
 131         bool bootstrap = false;
 132         int i;
 133
 134         for (i = 0; commands[i].cmd; i++) {
 135                 if (!strcmp(commands[i].cmd, "prog")) {
 136                         /* Assume we run a bootstrap version if "bpftool prog"
 137                          * is not available.
 138                          */
 139                         bootstrap = !commands[i].func;
 140                         break;
 141                 }
 142         }
 143
 144         if (json_output) {
 145                 jsonw_start_object(json_wtr);   /* root object */
 146
 147                 jsonw_name(json_wtr, "version");
 148 #ifdef BPFTOOL_VERSION
 149                 jsonw_printf(json_wtr, "\"%s\"", BPFTOOL_VERSION);
 150 #else
 151                 jsonw_printf(json_wtr, "\"%d.%d.%d\"", BPFTOOL_MAJOR_VERSION,
 152                              BPFTOOL_MINOR_VERSION, BPFTOOL_PATCH_VERSION);
 153 #endif
 154                 jsonw_name(json_wtr, "libbpf_version");
 155                 jsonw_printf(json_wtr, "\"%d.%d\"",
 156                              libbpf_major_version(), libbpf_minor_version());
 157
 158                 jsonw_name(json_wtr, "features");
 159                 jsonw_start_object(json_wtr);   /* features */
 160                 jsonw_bool_field(json_wtr, "libbfd", has_libbfd);
 161                 jsonw_bool_field(json_wtr, "llvm", has_llvm);
 162                 jsonw_bool_field(json_wtr, "skeletons", has_skeletons);
 163                 jsonw_bool_field(json_wtr, "bootstrap", bootstrap);
 164                 jsonw_end_object(json_wtr);     /* features */
 165
 166                 jsonw_end_object(json_wtr);     /* root object */
 167         } else {
 168                 unsigned int nb_features = 0;
 169
 170 #ifdef BPFTOOL_VERSION
 171                 printf("%s v%s\n", bin_name, BPFTOOL_VERSION);
 172 #else
 173                 printf("%s v%d.%d.%d\n", bin_name, BPFTOOL_MAJOR_VERSION,
 174                        BPFTOOL_MINOR_VERSION, BPFTOOL_PATCH_VERSION);
 175 #endif
 176                 printf("using libbpf %s\n", libbpf_version_string());
 177                 printf("features:");
 178                 print_feature("libbfd", has_libbfd, &nb_features);
 179                 print_feature("llvm", has_llvm, &nb_features);
 180                 print_feature("skeletons", has_skeletons, &nb_features);
 181                 print_feature("bootstrap", bootstrap, &nb_features);
 182                 printf("\n");
 183         }
 184         return 0;
 185 }
 186
 187 int cmd_select(const struct cmd *cmds, int argc, char **argv,
 188                int (*help)(int argc, char **argv))
 189 {
 190         unsigned int i;
 191
 192         last_argc = argc;
 193         last_argv = argv;
 194         last_do_help = help;
 195
 196         if (argc < 1 && cmds[0].func)
 197                 return cmds[0].func(argc, argv);
 198
 199         for (i = 0; cmds[i].cmd; i++) {
 200                 if (is_prefix(*argv, cmds[i].cmd)) {
 201                         if (!cmds[i].func) {
 202                                 p_err("command '%s' is not supported in bootstrap mode",
 203                                       cmds[i].cmd);
 204                                 return -1;
 205                         }
 206                         return cmds[i].func(argc - 1, argv + 1);
 207                 }
 208         }
 209
 210         help(argc - 1, argv + 1);
 211
 212         return -1;
 213 }
 214
 215 bool is_prefix(const char *pfx, const char *str)
 216 {
 217         if (!pfx)
 218                 return false;
 219         if (strlen(str) < strlen(pfx))
 220                 return false;
 221
 222         return !memcmp(str, pfx, strlen(pfx));
 223 }
 224
 225 /* Last argument MUST be NULL pointer */
 226 int detect_common_prefix(const char *arg, ...)
 227 {
 228         unsigned int count = 0;
 229         const char *ref;
 230         char msg[256];
 231         va_list ap;
 232
 233         snprintf(msg, sizeof(msg), "ambiguous prefix: '%s' could be '", arg);
 234         va_start(ap, arg);
 235         while ((ref = va_arg(ap, const char *))) {
 236                 if (!is_prefix(arg, ref))
 237                         continue;
 238                 count++;
 239                 if (count > 1)
 240                         strncat(msg, "' or '", sizeof(msg) - strlen(msg) - 1);
 241                 strncat(msg, ref, sizeof(msg) - strlen(msg) - 1);
 242         }
 243         va_end(ap);
 244         strncat(msg, "'", sizeof(msg) - strlen(msg) - 1);
 245
 246         if (count >= 2) {
 247                 p_err("%s", msg);
 248                 return -1;
 249         }
 250
 251         return 0;
 252 }
 253
 254 void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
 255 {
 256         unsigned char *data = arg;
 257         unsigned int i;
 258
 259         for (i = 0; i < n; i++) {
 260                 const char *pfx = "";
 261
 262                 if (!i)
 263                         /* nothing */;
 264                 else if (!(i % 16))
 265                         fprintf(f, "\n");
 266                 else if (!(i % 8))
 267                         fprintf(f, "  ");
 268                 else
 269                         pfx = sep;
 270
 271                 fprintf(f, "%s%02hhx", i ? pfx : "", data[i]);
 272         }
 273 }
 274
 275 /* Split command line into argument vector. */
 276 static int make_args(char *line, char *n_argv[], int maxargs, int cmd_nb)
 277 {
 278         static const char ws[] = " \t\r\n";
 279         char *cp = line;
 280         int n_argc = 0;
 281
 282         while (*cp) {
 283                 /* Skip leading whitespace. */
 284                 cp += strspn(cp, ws);
 285
 286                 if (*cp == '\0')
 287                         break;
 288
 289                 if (n_argc >= (maxargs - 1)) {
 290                         p_err("too many arguments to command %d", cmd_nb);
 291                         return -1;
 292                 }
 293
 294                 /* Word begins with quote. */
 295                 if (*cp == '\'' || *cp == '"') {
 296                         char quote = *cp++;
 297
 298                         n_argv[n_argc++] = cp;
 299                         /* Find ending quote. */
 300                         cp = strchr(cp, quote);
 301                         if (!cp) {
 302                                 p_err("unterminated quoted string in command %d",
 303                                       cmd_nb);
 304                                 return -1;
 305                         }
 306                 } else {
 307                         n_argv[n_argc++] = cp;
 308
 309                         /* Find end of word. */
 310                         cp += strcspn(cp, ws);
 311                         if (*cp == '\0')
 312                                 break;
 313                 }
 314
 315                 /* Separate words. */
 316                 *cp++ = 0;
 317         }
 318         n_argv[n_argc] = NULL;
 319
 320         return n_argc;
 321 }
 322
 323 static int do_batch(int argc, char **argv)
 324 {
 325         char buf[BATCH_LINE_LEN_MAX], contline[BATCH_LINE_LEN_MAX];
 326         char *n_argv[BATCH_ARG_NB_MAX];
 327         unsigned int lines = 0;
 328         int n_argc;
 329         FILE *fp;
 330         char *cp;
 331         int err = 0;
 332         int i;
 333
 334         if (argc < 2) {
 335                 p_err("too few parameters for batch");
 336                 return -1;
 337         } else if (argc > 2) {
 338                 p_err("too many parameters for batch");
 339                 return -1;
 340         } else if (!is_prefix(*argv, "file")) {
 341                 p_err("expected 'file', got: %s", *argv);
 342                 return -1;
 343         }
 344         NEXT_ARG();
 345
 346         if (!strcmp(*argv, "-"))
 347                 fp = stdin;
 348         else
 349                 fp = fopen(*argv, "r");
 350         if (!fp) {
 351                 p_err("Can't open file (%s): %s", *argv, strerror(errno));
 352                 return -1;
 353         }
 354
 355         if (json_output)
 356                 jsonw_start_array(json_wtr);
 357         while (fgets(buf, sizeof(buf), fp)) {
 358                 cp = strchr(buf, '#');
 359                 if (cp)
 360                         *cp = '\0';
 361
 362                 if (strlen(buf) == sizeof(buf) - 1) {
 363                         errno = E2BIG;
 364                         break;
 365                 }
 366
 367                 /* Append continuation lines if any (coming after a line ending
 368                  * with '\' in the batch file).
 369                  */
 370                 while ((cp = strstr(buf, "\\\n")) != NULL) {
 371                         if (!fgets(contline, sizeof(contline), fp) ||
 372                             strlen(contline) == 0) {
 373                                 p_err("missing continuation line on command %d",
 374                                       lines);
 375                                 err = -1;
 376                                 goto err_close;
 377                         }
 378
 379                         cp = strchr(contline, '#');
 380                         if (cp)
 381                                 *cp = '\0';
 382
 383                         if (strlen(buf) + strlen(contline) + 1 > sizeof(buf)) {
 384                                 p_err("command %d is too long", lines);
 385                                 err = -1;
 386                                 goto err_close;
 387                         }
 388                         buf[strlen(buf) - 2] = '\0';
 389                         strcat(buf, contline);
 390                 }
 391
 392                 n_argc = make_args(buf, n_argv, BATCH_ARG_NB_MAX, lines);
 393                 if (!n_argc)
 394                         continue;
 395                 if (n_argc < 0) {
 396                         err = n_argc;
 397                         goto err_close;
 398                 }
 399
 400                 if (json_output) {
 401                         jsonw_start_object(json_wtr);
 402                         jsonw_name(json_wtr, "command");
 403                         jsonw_start_array(json_wtr);
 404                         for (i = 0; i < n_argc; i++)
 405                                 jsonw_string(json_wtr, n_argv[i]);
 406                         jsonw_end_array(json_wtr);
 407                         jsonw_name(json_wtr, "output");
 408                 }
 409
 410                 err = cmd_select(commands, n_argc, n_argv, do_help);
 411
 412                 if (json_output)
 413                         jsonw_end_object(json_wtr);
 414
 415                 if (err)
 416                         goto err_close;
 417
 418                 lines++;
 419         }
 420
 421         if (errno && errno != ENOENT) {
 422                 p_err("reading batch file failed: %s", strerror(errno));
 423                 err = -1;
 424         } else {
 425                 if (!json_output)
 426                         printf("processed %d commands\n", lines);
 427         }
 428 err_close:
 429         if (fp != stdin)
 430                 fclose(fp);
 431
 432         if (json_output)
 433                 jsonw_end_array(json_wtr);
 434
 435         return err;
 436 }
 437
 438 int main(int argc, char **argv)
 439 {
 440         static const struct option options[] = {
 441                 { "json",       no_argument,    NULL,   'j' },
 442                 { "help",       no_argument,    NULL,   'h' },
 443                 { "pretty",     no_argument,    NULL,   'p' },
 444                 { "version",    no_argument,    NULL,   'V' },
 445                 { "bpffs",      no_argument,    NULL,   'f' },
 446                 { "mapcompat",  no_argument,    NULL,   'm' },
 447                 { "nomount",    no_argument,    NULL,   'n' },
 448                 { "debug",      no_argument,    NULL,   'd' },
 449                 { "use-loader", no_argument,    NULL,   'L' },
 450                 { "base-btf",   required_argument, NULL, 'B' },
 451                 { 0 }
 452         };
 453         bool version_requested = false;
 454         int opt, ret;
 455
 456         setlinebuf(stdout);
 457
 458 #ifdef USE_LIBCAP
 459         /* Libcap < 2.63 hooks before main() to compute the number of
 460          * capabilities of the running kernel, and doing so it calls prctl()
 461          * which may fail and set errno to non-zero.
 462          * Let's reset errno to make sure this does not interfere with the
 463          * batch mode.
 464          */
 465         errno = 0;
 466 #endif
 467
 468         last_do_help = do_help;
 469         pretty_output = false;
 470         json_output = false;
 471         show_pinned = false;
 472         block_mount = false;
 473         bin_name = "bpftool";
 474
 475         opterr = 0;
 476         while ((opt = getopt_long(argc, argv, "VhpjfLmndB:l",
 477                                   options, NULL)) >= 0) {
 478                 switch (opt) {
 479                 case 'V':
 480                         version_requested = true;
 481                         break;
 482                 case 'h':
 483                         return do_help(argc, argv);
 484                 case 'p':
 485                         pretty_output = true;
 486                         /* fall through */
 487                 case 'j':
 488                         if (!json_output) {
 489                                 json_wtr = jsonw_new(stdout);
 490                                 if (!json_wtr) {
 491                                         p_err("failed to create JSON writer");
 492                                         return -1;
 493                                 }
 494                                 json_output = true;
 495                         }
 496                         jsonw_pretty(json_wtr, pretty_output);
 497                         break;
 498                 case 'f':
 499                         show_pinned = true;
 500                         break;
 501                 case 'm':
 502                         relaxed_maps = true;
 503                         break;
 504                 case 'n':
 505                         block_mount = true;
 506                         break;
 507                 case 'd':
 508                         libbpf_set_print(print_all_levels);
 509                         verifier_logs = true;
 510                         break;
 511                 case 'B':
 512                         base_btf = btf__parse(optarg, NULL);
 513                         if (!base_btf) {
 514                                 p_err("failed to parse base BTF at '%s': %d\n",
 515                                       optarg, -errno);
 516                                 return -1;
 517                         }
 518                         break;
 519                 case 'L':
 520                         use_loader = true;
 521                         break;
 522                 default:
 523                         p_err("unrecognized option '%s'", argv[optind - 1]);
 524                         if (json_output)
 525                                 clean_and_exit(-1);
 526                         else
 527                                 usage();
 528                 }
 529         }
 530
 531         argc -= optind;
 532         argv += optind;
 533         if (argc < 0)
 534                 usage();
 535
 536         if (version_requested)
 537                 return do_version(argc, argv);
 538
 539         ret = cmd_select(commands, argc, argv, do_help);
 540
 541         if (json_output)
 542                 jsonw_destroy(&json_wtr);
 543
 544         btf__free(base_btf);
 545
 546         return ret;
 547 }