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