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