tools/bpf/bpftool/prog.c

   1 /*
   2  * Copyright (C) 2017 Netronome Systems, Inc.
   3  *
   4  * This software is dual licensed under the GNU General License Version 2,
   5  * June 1991 as shown in the file COPYING in the top-level directory of this
   6  * source tree or the BSD 2-Clause License provided below.  You have the
   7  * option to license this software under the complete terms of either license.
   8  *
   9  * The BSD 2-Clause License:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      1. Redistributions of source code must retain the above
  16  *         copyright notice, this list of conditions and the following
  17  *         disclaimer.
  18  *
  19  *      2. Redistributions in binary form must reproduce the above
  20  *         copyright notice, this list of conditions and the following
  21  *         disclaimer in the documentation and/or other materials
  22  *         provided with the distribution.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33
  34 /* Author: Jakub Kicinski <kubakici@wp.pl> */
  35
  36 #include <errno.h>
  37 #include <fcntl.h>
  38 #include <stdarg.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <time.h>
  43 #include <unistd.h>
  44 #include <net/if.h>
  45 #include <sys/types.h>
  46 #include <sys/stat.h>
  47
  48 #include <bpf.h>
  49
  50 #include "main.h"
  51 #include "disasm.h"
  52
  53 static const char * const prog_type_name[] = {
  54         [BPF_PROG_TYPE_UNSPEC]          = "unspec",
  55         [BPF_PROG_TYPE_SOCKET_FILTER]   = "socket_filter",
  56         [BPF_PROG_TYPE_KPROBE]          = "kprobe",
  57         [BPF_PROG_TYPE_SCHED_CLS]       = "sched_cls",
  58         [BPF_PROG_TYPE_SCHED_ACT]       = "sched_act",
  59         [BPF_PROG_TYPE_TRACEPOINT]      = "tracepoint",
  60         [BPF_PROG_TYPE_XDP]             = "xdp",
  61         [BPF_PROG_TYPE_PERF_EVENT]      = "perf_event",
  62         [BPF_PROG_TYPE_CGROUP_SKB]      = "cgroup_skb",
  63         [BPF_PROG_TYPE_CGROUP_SOCK]     = "cgroup_sock",
  64         [BPF_PROG_TYPE_LWT_IN]          = "lwt_in",
  65         [BPF_PROG_TYPE_LWT_OUT]         = "lwt_out",
  66         [BPF_PROG_TYPE_LWT_XMIT]        = "lwt_xmit",
  67         [BPF_PROG_TYPE_SOCK_OPS]        = "sock_ops",
  68         [BPF_PROG_TYPE_SK_SKB]          = "sk_skb",
  69 };
  70
  71 static void print_boot_time(__u64 nsecs, char *buf, unsigned int size)
  72 {
  73         struct timespec real_time_ts, boot_time_ts;
  74         time_t wallclock_secs;
  75         struct tm load_tm;
  76
  77         buf[--size] = '\0';
  78
  79         if (clock_gettime(CLOCK_REALTIME, &real_time_ts) ||
  80             clock_gettime(CLOCK_BOOTTIME, &boot_time_ts)) {
  81                 perror("Can't read clocks");
  82                 snprintf(buf, size, "%llu", nsecs / 1000000000);
  83                 return;
  84         }
  85
  86         wallclock_secs = (real_time_ts.tv_sec - boot_time_ts.tv_sec) +
  87                 nsecs / 1000000000;
  88
  89         if (!localtime_r(&wallclock_secs, &load_tm)) {
  90                 snprintf(buf, size, "%llu", nsecs / 1000000000);
  91                 return;
  92         }
  93
  94         strftime(buf, size, "%b %d/%H:%M", &load_tm);
  95 }
  96
  97 static int prog_fd_by_tag(unsigned char *tag)
  98 {
  99         struct bpf_prog_info info = {};
 100         __u32 len = sizeof(info);
 101         unsigned int id = 0;
 102         int err;
 103         int fd;
 104
 105         while (true) {
 106                 err = bpf_prog_get_next_id(id, &id);
 107                 if (err) {
 108                         p_err("%s", strerror(errno));
 109                         return -1;
 110                 }
 111
 112                 fd = bpf_prog_get_fd_by_id(id);
 113                 if (fd < 0) {
 114                         p_err("can't get prog by id (%u): %s",
 115                               id, strerror(errno));
 116                         return -1;
 117                 }
 118
 119                 err = bpf_obj_get_info_by_fd(fd, &info, &len);
 120                 if (err) {
 121                         p_err("can't get prog info (%u): %s",
 122                               id, strerror(errno));
 123                         close(fd);
 124                         return -1;
 125                 }
 126
 127                 if (!memcmp(tag, info.tag, BPF_TAG_SIZE))
 128                         return fd;
 129
 130                 close(fd);
 131         }
 132 }
 133
 134 int prog_parse_fd(int *argc, char ***argv)
 135 {
 136         int fd;
 137
 138         if (is_prefix(**argv, "id")) {
 139                 unsigned int id;
 140                 char *endptr;
 141
 142                 NEXT_ARGP();
 143
 144                 id = strtoul(**argv, &endptr, 0);
 145                 if (*endptr) {
 146                         p_err("can't parse %s as ID", **argv);
 147                         return -1;
 148                 }
 149                 NEXT_ARGP();
 150
 151                 fd = bpf_prog_get_fd_by_id(id);
 152                 if (fd < 0)
 153                         p_err("get by id (%u): %s", id, strerror(errno));
 154                 return fd;
 155         } else if (is_prefix(**argv, "tag")) {
 156                 unsigned char tag[BPF_TAG_SIZE];
 157
 158                 NEXT_ARGP();
 159
 160                 if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2,
 161                            tag + 3, tag + 4, tag + 5, tag + 6, tag + 7)
 162                     != BPF_TAG_SIZE) {
 163                         p_err("can't parse tag");
 164                         return -1;
 165                 }
 166                 NEXT_ARGP();
 167
 168                 return prog_fd_by_tag(tag);
 169         } else if (is_prefix(**argv, "pinned")) {
 170                 char *path;
 171
 172                 NEXT_ARGP();
 173
 174                 path = **argv;
 175                 NEXT_ARGP();
 176
 177                 return open_obj_pinned_any(path, BPF_OBJ_PROG);
 178         }
 179
 180         p_err("expected 'id', 'tag' or 'pinned', got: '%s'?", **argv);
 181         return -1;
 182 }
 183
 184 static void show_prog_maps(int fd, u32 num_maps)
 185 {
 186         struct bpf_prog_info info = {};
 187         __u32 len = sizeof(info);
 188         __u32 map_ids[num_maps];
 189         unsigned int i;
 190         int err;
 191
 192         info.nr_map_ids = num_maps;
 193         info.map_ids = ptr_to_u64(map_ids);
 194
 195         err = bpf_obj_get_info_by_fd(fd, &info, &len);
 196         if (err || !info.nr_map_ids)
 197                 return;
 198
 199         if (json_output) {
 200                 jsonw_name(json_wtr, "map_ids");
 201                 jsonw_start_array(json_wtr);
 202                 for (i = 0; i < info.nr_map_ids; i++)
 203                         jsonw_uint(json_wtr, map_ids[i]);
 204                 jsonw_end_array(json_wtr);
 205         } else {
 206                 printf("  map_ids ");
 207                 for (i = 0; i < info.nr_map_ids; i++)
 208                         printf("%u%s", map_ids[i],
 209                                i == info.nr_map_ids - 1 ? "" : ",");
 210         }
 211 }
 212
 213 static void print_prog_json(struct bpf_prog_info *info, int fd)
 214 {
 215         char *memlock;
 216
 217         jsonw_start_object(json_wtr);
 218         jsonw_uint_field(json_wtr, "id", info->id);
 219         if (info->type < ARRAY_SIZE(prog_type_name))
 220                 jsonw_string_field(json_wtr, "type",
 221                                    prog_type_name[info->type]);
 222         else
 223                 jsonw_uint_field(json_wtr, "type", info->type);
 224
 225         if (*info->name)
 226                 jsonw_string_field(json_wtr, "name", info->name);
 227
 228         jsonw_name(json_wtr, "tag");
 229         jsonw_printf(json_wtr, "\"" BPF_TAG_FMT "\"",
 230                      info->tag[0], info->tag[1], info->tag[2], info->tag[3],
 231                      info->tag[4], info->tag[5], info->tag[6], info->tag[7]);
 232
 233         if (info->status & BPF_PROG_STATUS_DEV_BOUND) {
 234                 jsonw_name(json_wtr, "dev");
 235                 if (info->ifindex) {
 236                         char name[IF_NAMESIZE];
 237
 238                         if (!if_indextoname(info->ifindex, name))
 239                                 jsonw_printf(json_wtr, "\"ifindex:%d\"",
 240                                              info->ifindex);
 241                         else
 242                                 jsonw_printf(json_wtr, "\"%s\"", name);
 243                 } else {
 244                         jsonw_printf(json_wtr, "\"unknown\"");
 245                 }
 246         }
 247
 248         if (info->load_time) {
 249                 char buf[32];
 250
 251                 print_boot_time(info->load_time, buf, sizeof(buf));
 252
 253                 /* Piggy back on load_time, since 0 uid is a valid one */
 254                 jsonw_string_field(json_wtr, "loaded_at", buf);
 255                 jsonw_uint_field(json_wtr, "uid", info->created_by_uid);
 256         }
 257
 258         jsonw_uint_field(json_wtr, "bytes_xlated", info->xlated_prog_len);
 259
 260         if (info->jited_prog_len) {
 261                 jsonw_bool_field(json_wtr, "jited", true);
 262                 jsonw_uint_field(json_wtr, "bytes_jited", info->jited_prog_len);
 263         } else {
 264                 jsonw_bool_field(json_wtr, "jited", false);
 265         }
 266
 267         memlock = get_fdinfo(fd, "memlock");
 268         if (memlock)
 269                 jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
 270         free(memlock);
 271
 272         if (info->nr_map_ids)
 273                 show_prog_maps(fd, info->nr_map_ids);
 274
 275         if (!hash_empty(prog_table.table)) {
 276                 struct pinned_obj *obj;
 277
 278                 jsonw_name(json_wtr, "pinned");
 279                 jsonw_start_array(json_wtr);
 280                 hash_for_each_possible(prog_table.table, obj, hash, info->id) {
 281                         if (obj->id == info->id)
 282                                 jsonw_string(json_wtr, obj->path);
 283                 }
 284                 jsonw_end_array(json_wtr);
 285         }
 286
 287         jsonw_end_object(json_wtr);
 288 }
 289
 290 static void print_prog_plain(struct bpf_prog_info *info, int fd)
 291 {
 292         char *memlock;
 293
 294         printf("%u: ", info->id);
 295         if (info->type < ARRAY_SIZE(prog_type_name))
 296                 printf("%s  ", prog_type_name[info->type]);
 297         else
 298                 printf("type %u  ", info->type);
 299
 300         if (*info->name)
 301                 printf("name %s  ", info->name);
 302
 303         printf("tag ");
 304         fprint_hex(stdout, info->tag, BPF_TAG_SIZE, "");
 305         printf(" ");
 306
 307         if (info->status & BPF_PROG_STATUS_DEV_BOUND) {
 308                 printf("dev ");
 309                 if (info->ifindex) {
 310                         char name[IF_NAMESIZE];
 311
 312                         if (!if_indextoname(info->ifindex, name))
 313                                 printf("ifindex:%d ", info->ifindex);
 314                         else
 315                                 printf("%s ", name);
 316                 } else {
 317                         printf("unknown ");
 318                 }
 319         }
 320         printf("\n");
 321
 322         if (info->load_time) {
 323                 char buf[32];
 324
 325                 print_boot_time(info->load_time, buf, sizeof(buf));
 326
 327                 /* Piggy back on load_time, since 0 uid is a valid one */
 328                 printf("\tloaded_at %s  uid %u\n", buf, info->created_by_uid);
 329         }
 330
 331         printf("\txlated %uB", info->xlated_prog_len);
 332
 333         if (info->jited_prog_len)
 334                 printf("  jited %uB", info->jited_prog_len);
 335         else
 336                 printf("  not jited");
 337
 338         memlock = get_fdinfo(fd, "memlock");
 339         if (memlock)
 340                 printf("  memlock %sB", memlock);
 341         free(memlock);
 342
 343         if (info->nr_map_ids)
 344                 show_prog_maps(fd, info->nr_map_ids);
 345
 346         if (!hash_empty(prog_table.table)) {
 347                 struct pinned_obj *obj;
 348
 349                 printf("\n");
 350                 hash_for_each_possible(prog_table.table, obj, hash, info->id) {
 351                         if (obj->id == info->id)
 352                                 printf("\tpinned %s\n", obj->path);
 353                 }
 354         }
 355
 356         printf("\n");
 357 }
 358
 359 static int show_prog(int fd)
 360 {
 361         struct bpf_prog_info info = {};
 362         __u32 len = sizeof(info);
 363         int err;
 364
 365         err = bpf_obj_get_info_by_fd(fd, &info, &len);
 366         if (err) {
 367                 p_err("can't get prog info: %s", strerror(errno));
 368                 return -1;
 369         }
 370
 371         if (json_output)
 372                 print_prog_json(&info, fd);
 373         else
 374                 print_prog_plain(&info, fd);
 375
 376         return 0;
 377 }
 378
 379 static int do_show(int argc, char **argv)
 380 {
 381         __u32 id = 0;
 382         int err;
 383         int fd;
 384
 385         if (show_pinned)
 386                 build_pinned_obj_table(&prog_table, BPF_OBJ_PROG);
 387
 388         if (argc == 2) {
 389                 fd = prog_parse_fd(&argc, &argv);
 390                 if (fd < 0)
 391                         return -1;
 392
 393                 return show_prog(fd);
 394         }
 395
 396         if (argc)
 397                 return BAD_ARG();
 398
 399         if (json_output)
 400                 jsonw_start_array(json_wtr);
 401         while (true) {
 402                 err = bpf_prog_get_next_id(id, &id);
 403                 if (err) {
 404                         if (errno == ENOENT) {
 405                                 err = 0;
 406                                 break;
 407                         }
 408                         p_err("can't get next program: %s%s", strerror(errno),
 409                               errno == EINVAL ? " -- kernel too old?" : "");
 410                         err = -1;
 411                         break;
 412                 }
 413
 414                 fd = bpf_prog_get_fd_by_id(id);
 415                 if (fd < 0) {
 416                         p_err("can't get prog by id (%u): %s",
 417                               id, strerror(errno));
 418                         err = -1;
 419                         break;
 420                 }
 421
 422                 err = show_prog(fd);
 423                 close(fd);
 424                 if (err)
 425                         break;
 426         }
 427
 428         if (json_output)
 429                 jsonw_end_array(json_wtr);
 430
 431         return err;
 432 }
 433
 434 static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...)
 435 {
 436         va_list args;
 437
 438         va_start(args, fmt);
 439         vprintf(fmt, args);
 440         va_end(args);
 441 }
 442
 443 static void dump_xlated_plain(void *buf, unsigned int len, bool opcodes)
 444 {
 445         struct bpf_insn *insn = buf;
 446         bool double_insn = false;
 447         unsigned int i;
 448
 449         for (i = 0; i < len / sizeof(*insn); i++) {
 450                 if (double_insn) {
 451                         double_insn = false;
 452                         continue;
 453                 }
 454
 455                 double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
 456
 457                 printf("% 4d: ", i);
 458                 print_bpf_insn(print_insn, NULL, insn + i, true);
 459
 460                 if (opcodes) {
 461                         printf("       ");
 462                         fprint_hex(stdout, insn + i, 8, " ");
 463                         if (double_insn && i < len - 1) {
 464                                 printf(" ");
 465                                 fprint_hex(stdout, insn + i + 1, 8, " ");
 466                         }
 467                         printf("\n");
 468                 }
 469         }
 470 }
 471
 472 static void print_insn_json(struct bpf_verifier_env *env, const char *fmt, ...)
 473 {
 474         unsigned int l = strlen(fmt);
 475         char chomped_fmt[l];
 476         va_list args;
 477
 478         va_start(args, fmt);
 479         if (l > 0) {
 480                 strncpy(chomped_fmt, fmt, l - 1);
 481                 chomped_fmt[l - 1] = '\0';
 482         }
 483         jsonw_vprintf_enquote(json_wtr, chomped_fmt, args);
 484         va_end(args);
 485 }
 486
 487 static void dump_xlated_json(void *buf, unsigned int len, bool opcodes)
 488 {
 489         struct bpf_insn *insn = buf;
 490         bool double_insn = false;
 491         unsigned int i;
 492
 493         jsonw_start_array(json_wtr);
 494         for (i = 0; i < len / sizeof(*insn); i++) {
 495                 if (double_insn) {
 496                         double_insn = false;
 497                         continue;
 498                 }
 499                 double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
 500
 501                 jsonw_start_object(json_wtr);
 502                 jsonw_name(json_wtr, "disasm");
 503                 print_bpf_insn(print_insn_json, NULL, insn + i, true);
 504
 505                 if (opcodes) {
 506                         jsonw_name(json_wtr, "opcodes");
 507                         jsonw_start_object(json_wtr);
 508
 509                         jsonw_name(json_wtr, "code");
 510                         jsonw_printf(json_wtr, "\"0x%02hhx\"", insn[i].code);
 511
 512                         jsonw_name(json_wtr, "src_reg");
 513                         jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].src_reg);
 514
 515                         jsonw_name(json_wtr, "dst_reg");
 516                         jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].dst_reg);
 517
 518                         jsonw_name(json_wtr, "off");
 519                         print_hex_data_json((uint8_t *)(&insn[i].off), 2);
 520
 521                         jsonw_name(json_wtr, "imm");
 522                         if (double_insn && i < len - 1)
 523                                 print_hex_data_json((uint8_t *)(&insn[i].imm),
 524                                                     12);
 525                         else
 526                                 print_hex_data_json((uint8_t *)(&insn[i].imm),
 527                                                     4);
 528                         jsonw_end_object(json_wtr);
 529                 }
 530                 jsonw_end_object(json_wtr);
 531         }
 532         jsonw_end_array(json_wtr);
 533 }
 534
 535 static int do_dump(int argc, char **argv)
 536 {
 537         struct bpf_prog_info info = {};
 538         __u32 len = sizeof(info);
 539         unsigned int buf_size;
 540         char *filepath = NULL;
 541         bool opcodes = false;
 542         unsigned char *buf;
 543         __u32 *member_len;
 544         __u64 *member_ptr;
 545         ssize_t n;
 546         int err;
 547         int fd;
 548
 549         if (is_prefix(*argv, "jited")) {
 550                 member_len = &info.jited_prog_len;
 551                 member_ptr = &info.jited_prog_insns;
 552         } else if (is_prefix(*argv, "xlated")) {
 553                 member_len = &info.xlated_prog_len;
 554                 member_ptr = &info.xlated_prog_insns;
 555         } else {
 556                 p_err("expected 'xlated' or 'jited', got: %s", *argv);
 557                 return -1;
 558         }
 559         NEXT_ARG();
 560
 561         if (argc < 2)
 562                 usage();
 563
 564         fd = prog_parse_fd(&argc, &argv);
 565         if (fd < 0)
 566                 return -1;
 567
 568         if (is_prefix(*argv, "file")) {
 569                 NEXT_ARG();
 570                 if (!argc) {
 571                         p_err("expected file path");
 572                         return -1;
 573                 }
 574
 575                 filepath = *argv;
 576                 NEXT_ARG();
 577         } else if (is_prefix(*argv, "opcodes")) {
 578                 opcodes = true;
 579                 NEXT_ARG();
 580         }
 581
 582         if (argc) {
 583                 usage();
 584                 return -1;
 585         }
 586
 587         err = bpf_obj_get_info_by_fd(fd, &info, &len);
 588         if (err) {
 589                 p_err("can't get prog info: %s", strerror(errno));
 590                 return -1;
 591         }
 592
 593         if (!*member_len) {
 594                 p_info("no instructions returned");
 595                 close(fd);
 596                 return 0;
 597         }
 598
 599         buf_size = *member_len;
 600
 601         buf = malloc(buf_size);
 602         if (!buf) {
 603                 p_err("mem alloc failed");
 604                 close(fd);
 605                 return -1;
 606         }
 607
 608         memset(&info, 0, sizeof(info));
 609
 610         *member_ptr = ptr_to_u64(buf);
 611         *member_len = buf_size;
 612
 613         err = bpf_obj_get_info_by_fd(fd, &info, &len);
 614         close(fd);
 615         if (err) {
 616                 p_err("can't get prog info: %s", strerror(errno));
 617                 goto err_free;
 618         }
 619
 620         if (*member_len > buf_size) {
 621                 p_err("too many instructions returned");
 622                 goto err_free;
 623         }
 624
 625         if (filepath) {
 626                 fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 627                 if (fd < 0) {
 628                         p_err("can't open file %s: %s", filepath,
 629                               strerror(errno));
 630                         goto err_free;
 631                 }
 632
 633                 n = write(fd, buf, *member_len);
 634                 close(fd);
 635                 if (n != *member_len) {
 636                         p_err("error writing output file: %s",
 637                               n < 0 ? strerror(errno) : "short write");
 638                         goto err_free;
 639                 }
 640         } else {
 641                 if (member_len == &info.jited_prog_len)
 642                         disasm_print_insn(buf, *member_len, opcodes);
 643                 else
 644                         if (json_output)
 645                                 dump_xlated_json(buf, *member_len, opcodes);
 646                         else
 647                                 dump_xlated_plain(buf, *member_len, opcodes);
 648         }
 649
 650         free(buf);
 651
 652         return 0;
 653
 654 err_free:
 655         free(buf);
 656         return -1;
 657 }
 658
 659 static int do_pin(int argc, char **argv)
 660 {
 661         int err;
 662
 663         err = do_pin_any(argc, argv, bpf_prog_get_fd_by_id);
 664         if (!err && json_output)
 665                 jsonw_null(json_wtr);
 666         return err;
 667 }
 668
 669 static int do_help(int argc, char **argv)
 670 {
 671         if (json_output) {
 672                 jsonw_null(json_wtr);
 673                 return 0;
 674         }
 675
 676         fprintf(stderr,
 677                 "Usage: %s %s show [PROG]\n"
 678                 "       %s %s dump xlated PROG [{ file FILE | opcodes }]\n"
 679                 "       %s %s dump jited  PROG [{ file FILE | opcodes }]\n"
 680                 "       %s %s pin   PROG FILE\n"
 681                 "       %s %s help\n"
 682                 "\n"
 683                 "       " HELP_SPEC_PROGRAM "\n"
 684                 "       " HELP_SPEC_OPTIONS "\n"
 685                 "",
 686                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
 687                 bin_name, argv[-2], bin_name, argv[-2]);
 688
 689         return 0;
 690 }
 691
 692 static const struct cmd cmds[] = {
 693         { "show",       do_show },
 694         { "help",       do_help },
 695         { "dump",       do_dump },
 696         { "pin",        do_pin },
 697         { 0 }
 698 };
 699
 700 int do_prog(int argc, char **argv)
 701 {
 702         return cmd_select(cmds, argc, argv, do_help);
 703 }