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