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