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_version(int argc, char **argv)
  74 {
  75 #ifdef HAVE_LIBBFD_SUPPORT
  76         const bool has_libbfd = true;
  77 #else
  78         const bool has_libbfd = false;
  79 #endif
  80 #ifdef BPFTOOL_WITHOUT_SKELETONS
  81         const bool has_skeletons = false;
  82 #else
  83         const bool has_skeletons = true;
  84 #endif
  85
  86         if (json_output) {
  87                 jsonw_start_object(json_wtr);   /* root object */
  88
  89                 jsonw_name(json_wtr, "version");
  90                 jsonw_printf(json_wtr, "\"%s\"", BPFTOOL_VERSION);
  91
  92                 jsonw_name(json_wtr, "features");
  93                 jsonw_start_object(json_wtr);   /* features */
  94                 jsonw_bool_field(json_wtr, "libbfd", has_libbfd);
  95                 jsonw_bool_field(json_wtr, "skeletons", has_skeletons);
  96                 jsonw_end_object(json_wtr);     /* features */
  97
  98                 jsonw_end_object(json_wtr);     /* root object */
  99         } else {
 100                 unsigned int nb_features = 0;
 101
 102                 printf("%s v%s\n", bin_name, BPFTOOL_VERSION);
 103                 printf("features:");
 104                 if (has_libbfd) {
 105                         printf(" libbfd");
 106                         nb_features++;
 107                 }
 108                 if (has_skeletons)
 109                         printf("%s skeletons", nb_features++ ? "," : "");
 110                 printf("\n");
 111         }
 112         return 0;
 113 }
 114
 115 int cmd_select(const struct cmd *cmds, int argc, char **argv,
 116                int (*help)(int argc, char **argv))
 117 {
 118         unsigned int i;
 119
 120         last_argc = argc;
 121         last_argv = argv;
 122         last_do_help = help;
 123
 124         if (argc < 1 && cmds[0].func)
 125                 return cmds[0].func(argc, argv);
 126
 127         for (i = 0; cmds[i].cmd; i++) {
 128                 if (is_prefix(*argv, cmds[i].cmd)) {
 129                         if (!cmds[i].func) {
 130                                 p_err("command '%s' is not supported in bootstrap mode",
 131                                       cmds[i].cmd);
 132                                 return -1;
 133                         }
 134                         return cmds[i].func(argc - 1, argv + 1);
 135                 }
 136         }
 137
 138         help(argc - 1, argv + 1);
 139
 140         return -1;
 141 }
 142
 143 bool is_prefix(const char *pfx, const char *str)
 144 {
 145         if (!pfx)
 146                 return false;
 147         if (strlen(str) < strlen(pfx))
 148                 return false;
 149
 150         return !memcmp(str, pfx, strlen(pfx));
 151 }
 152
 153 /* Last argument MUST be NULL pointer */
 154 int detect_common_prefix(const char *arg, ...)
 155 {
 156         unsigned int count = 0;
 157         const char *ref;
 158         char msg[256];
 159         va_list ap;
 160
 161         snprintf(msg, sizeof(msg), "ambiguous prefix: '%s' could be '", arg);
 162         va_start(ap, arg);
 163         while ((ref = va_arg(ap, const char *))) {
 164                 if (!is_prefix(arg, ref))
 165                         continue;
 166                 count++;
 167                 if (count > 1)
 168                         strncat(msg, "' or '", sizeof(msg) - strlen(msg) - 1);
 169                 strncat(msg, ref, sizeof(msg) - strlen(msg) - 1);
 170         }
 171         va_end(ap);
 172         strncat(msg, "'", sizeof(msg) - strlen(msg) - 1);
 173
 174         if (count >= 2) {
 175                 p_err("%s", msg);
 176                 return -1;
 177         }
 178
 179         return 0;
 180 }
 181
 182 void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
 183 {
 184         unsigned char *data = arg;
 185         unsigned int i;
 186
 187         for (i = 0; i < n; i++) {
 188                 const char *pfx = "";
 189
 190                 if (!i)
 191                         /* nothing */;
 192                 else if (!(i % 16))
 193                         fprintf(f, "\n");
 194                 else if (!(i % 8))
 195                         fprintf(f, "  ");
 196                 else
 197                         pfx = sep;
 198
 199                 fprintf(f, "%s%02hhx", i ? pfx : "", data[i]);
 200         }
 201 }
 202
 203 /* Split command line into argument vector. */
 204 static int make_args(char *line, char *n_argv[], int maxargs, int cmd_nb)
 205 {
 206         static const char ws[] = " \t\r\n";
 207         char *cp = line;
 208         int n_argc = 0;
 209
 210         while (*cp) {
 211                 /* Skip leading whitespace. */
 212                 cp += strspn(cp, ws);
 213
 214                 if (*cp == '\0')
 215                         break;
 216
 217                 if (n_argc >= (maxargs - 1)) {
 218                         p_err("too many arguments to command %d", cmd_nb);
 219                         return -1;
 220                 }
 221
 222                 /* Word begins with quote. */
 223                 if (*cp == '\'' || *cp == '"') {
 224                         char quote = *cp++;
 225
 226                         n_argv[n_argc++] = cp;
 227                         /* Find ending quote. */
 228                         cp = strchr(cp, quote);
 229                         if (!cp) {
 230                                 p_err("unterminated quoted string in command %d",
 231                                       cmd_nb);
 232                                 return -1;
 233                         }
 234                 } else {
 235                         n_argv[n_argc++] = cp;
 236
 237                         /* Find end of word. */
 238                         cp += strcspn(cp, ws);
 239                         if (*cp == '\0')
 240                                 break;
 241                 }
 242
 243                 /* Separate words. */
 244                 *cp++ = 0;
 245         }
 246         n_argv[n_argc] = NULL;
 247
 248         return n_argc;
 249 }
 250
 251 static int do_batch(int argc, char **argv);
 252
 253 static const struct cmd cmds[] = {
 254         { "help",       do_help },
 255         { "batch",      do_batch },
 256         { "prog",       do_prog },
 257         { "map",        do_map },
 258         { "link",       do_link },
 259         { "cgroup",     do_cgroup },
 260         { "perf",       do_perf },
 261         { "net",        do_net },
 262         { "feature",    do_feature },
 263         { "btf",        do_btf },
 264         { "gen",        do_gen },
 265         { "struct_ops", do_struct_ops },
 266         { "iter",       do_iter },
 267         { "version",    do_version },
 268         { 0 }
 269 };
 270
 271 static int do_batch(int argc, char **argv)
 272 {
 273         char buf[BATCH_LINE_LEN_MAX], contline[BATCH_LINE_LEN_MAX];
 274         char *n_argv[BATCH_ARG_NB_MAX];
 275         unsigned int lines = 0;
 276         int n_argc;
 277         FILE *fp;
 278         char *cp;
 279         int err = 0;
 280         int i;
 281
 282         if (argc < 2) {
 283                 p_err("too few parameters for batch");
 284                 return -1;
 285         } else if (!is_prefix(*argv, "file")) {
 286                 p_err("expected 'file', got: %s", *argv);
 287                 return -1;
 288         } else if (argc > 2) {
 289                 p_err("too many parameters for batch");
 290                 return -1;
 291         }
 292         NEXT_ARG();
 293
 294         if (!strcmp(*argv, "-"))
 295                 fp = stdin;
 296         else
 297                 fp = fopen(*argv, "r");
 298         if (!fp) {
 299                 p_err("Can't open file (%s): %s", *argv, strerror(errno));
 300                 return -1;
 301         }
 302
 303         if (json_output)
 304                 jsonw_start_array(json_wtr);
 305         while (fgets(buf, sizeof(buf), fp)) {
 306                 cp = strchr(buf, '#');
 307                 if (cp)
 308                         *cp = '\0';
 309
 310                 if (strlen(buf) == sizeof(buf) - 1) {
 311                         errno = E2BIG;
 312                         break;
 313                 }
 314
 315                 /* Append continuation lines if any (coming after a line ending
 316                  * with '\' in the batch file).
 317                  */
 318                 while ((cp = strstr(buf, "\\\n")) != NULL) {
 319                         if (!fgets(contline, sizeof(contline), fp) ||
 320                             strlen(contline) == 0) {
 321                                 p_err("missing continuation line on command %d",
 322                                       lines);
 323                                 err = -1;
 324                                 goto err_close;
 325                         }
 326
 327                         cp = strchr(contline, '#');
 328                         if (cp)
 329                                 *cp = '\0';
 330
 331                         if (strlen(buf) + strlen(contline) + 1 > sizeof(buf)) {
 332                                 p_err("command %d is too long", lines);
 333                                 err = -1;
 334                                 goto err_close;
 335                         }
 336                         buf[strlen(buf) - 2] = '\0';
 337                         strcat(buf, contline);
 338                 }
 339
 340                 n_argc = make_args(buf, n_argv, BATCH_ARG_NB_MAX, lines);
 341                 if (!n_argc)
 342                         continue;
 343                 if (n_argc < 0) {
 344                         err = n_argc;
 345                         goto err_close;
 346                 }
 347
 348                 if (json_output) {
 349                         jsonw_start_object(json_wtr);
 350                         jsonw_name(json_wtr, "command");
 351                         jsonw_start_array(json_wtr);
 352                         for (i = 0; i < n_argc; i++)
 353                                 jsonw_string(json_wtr, n_argv[i]);
 354                         jsonw_end_array(json_wtr);
 355                         jsonw_name(json_wtr, "output");
 356                 }
 357
 358                 err = cmd_select(cmds, n_argc, n_argv, do_help);
 359
 360                 if (json_output)
 361                         jsonw_end_object(json_wtr);
 362
 363                 if (err)
 364                         goto err_close;
 365
 366                 lines++;
 367         }
 368
 369         if (errno && errno != ENOENT) {
 370                 p_err("reading batch file failed: %s", strerror(errno));
 371                 err = -1;
 372         } else {
 373                 if (!json_output)
 374                         printf("processed %d commands\n", lines);
 375         }
 376 err_close:
 377         if (fp != stdin)
 378                 fclose(fp);
 379
 380         if (json_output)
 381                 jsonw_end_array(json_wtr);
 382
 383         return err;
 384 }
 385
 386 int main(int argc, char **argv)
 387 {
 388         static const struct option options[] = {
 389                 { "json",       no_argument,    NULL,   'j' },
 390                 { "help",       no_argument,    NULL,   'h' },
 391                 { "pretty",     no_argument,    NULL,   'p' },
 392                 { "version",    no_argument,    NULL,   'V' },
 393                 { "bpffs",      no_argument,    NULL,   'f' },
 394                 { "mapcompat",  no_argument,    NULL,   'm' },
 395                 { "nomount",    no_argument,    NULL,   'n' },
 396                 { "debug",      no_argument,    NULL,   'd' },
 397                 { "use-loader", no_argument,    NULL,   'L' },
 398                 { "base-btf",   required_argument, NULL, 'B' },
 399                 { 0 }
 400         };
 401         int opt, ret;
 402
 403         last_do_help = do_help;
 404         pretty_output = false;
 405         json_output = false;
 406         show_pinned = false;
 407         block_mount = false;
 408         bin_name = argv[0];
 409
 410         opterr = 0;
 411         while ((opt = getopt_long(argc, argv, "VhpjfLmndB:",
 412                                   options, NULL)) >= 0) {
 413                 switch (opt) {
 414                 case 'V':
 415                         return do_version(argc, argv);
 416                 case 'h':
 417                         return do_help(argc, argv);
 418                 case 'p':
 419                         pretty_output = true;
 420                         /* fall through */
 421                 case 'j':
 422                         if (!json_output) {
 423                                 json_wtr = jsonw_new(stdout);
 424                                 if (!json_wtr) {
 425                                         p_err("failed to create JSON writer");
 426                                         return -1;
 427                                 }
 428                                 json_output = true;
 429                         }
 430                         jsonw_pretty(json_wtr, pretty_output);
 431                         break;
 432                 case 'f':
 433                         show_pinned = true;
 434                         break;
 435                 case 'm':
 436                         relaxed_maps = true;
 437                         break;
 438                 case 'n':
 439                         block_mount = true;
 440                         break;
 441                 case 'd':
 442                         libbpf_set_print(print_all_levels);
 443                         verifier_logs = true;
 444                         break;
 445                 case 'B':
 446                         base_btf = btf__parse(optarg, NULL);
 447                         if (libbpf_get_error(base_btf)) {
 448                                 p_err("failed to parse base BTF at '%s': %ld\n",
 449                                       optarg, libbpf_get_error(base_btf));
 450                                 base_btf = NULL;
 451                                 return -1;
 452                         }
 453                         break;
 454                 case 'L':
 455                         use_loader = true;
 456                         break;
 457                 default:
 458                         p_err("unrecognized option '%s'", argv[optind - 1]);
 459                         if (json_output)
 460                                 clean_and_exit(-1);
 461                         else
 462                                 usage();
 463                 }
 464         }
 465
 466         argc -= optind;
 467         argv += optind;
 468         if (argc < 0)
 469                 usage();
 470
 471         ret = cmd_select(cmds, argc, argv, do_help);
 472
 473         if (json_output)
 474                 jsonw_destroy(&json_wtr);
 475
 476         btf__free(base_btf);
 477
 478         return ret;
 479 }