kmodloader.c

   1 /*
   2  * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #define _GNU_SOURCE
  16 #include <sys/syscall.h>
  17 #include <sys/mman.h>
  18 #include <sys/utsname.h>
  19
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include <sys/syscall.h>
  23 #include <sys/types.h>
  24 #include <values.h>
  25 #include <errno.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <sys/stat.h>
  29 #include <fcntl.h>
  30 #include <syslog.h>
  31 #include <libgen.h>
  32 #include <glob.h>
  33 #include <elf.h>
  34
  35 #include <libubox/avl.h>
  36 #include <libubox/avl-cmp.h>
  37 #include <libubox/utils.h>
  38 #include <libubox/ulog.h>
  39
  40 #define DEF_MOD_PATH "/modules/%s/"
  41
  42 enum {
  43         SCANNED,
  44         PROBE,
  45         LOADED,
  46 };
  47
  48 struct module {
  49         struct avl_node avl;
  50
  51         char *name;
  52         char *depends;
  53         char *opts;
  54
  55         int size;
  56         int usage;
  57         int state;
  58         int error;
  59 };
  60
  61 static struct avl_tree modules;
  62
  63 static char **module_folders = NULL;
  64
  65 static int init_module_folders(void)
  66 {
  67         int n = 0;
  68         struct stat st;
  69         struct utsname ver;
  70         char *s, *e, *p, path[256], ldpath[256];
  71
  72         e = ldpath;
  73         s = getenv("LD_LIBRARY_PATH");
  74
  75         if (s)
  76                 e += snprintf(ldpath, sizeof(ldpath), "%s:", s);
  77
  78         e += snprintf(e, sizeof(ldpath) - (e - ldpath), "/lib");
  79
  80         uname(&ver);
  81
  82         for (s = p = ldpath; p <= e; p++) {
  83                 if (*p != ':' && *p != '\0')
  84                         continue;
  85
  86                 *p = 0;
  87                 snprintf(path, sizeof(path), "%s" DEF_MOD_PATH, s, ver.release);
  88
  89                 if (!stat(path, &st) && S_ISDIR(st.st_mode)) {
  90                         module_folders = realloc(module_folders, sizeof(p) * (n + 2));
  91
  92                         if (!module_folders)
  93                                 return -1;
  94
  95                         module_folders[n++] = strdup(path);
  96                 }
  97
  98                 s = p + 1;
  99         }
 100
 101         if (!module_folders)
 102                 return -1;
 103
 104         module_folders[n] = NULL;
 105         return 0;
 106 }
 107
 108 static struct module *find_module(const char *name)
 109 {
 110         struct module *m;
 111         return avl_find_element(&modules, name, m, avl);
 112 }
 113
 114 static void free_modules(void)
 115 {
 116         struct module *m, *tmp;
 117
 118         avl_remove_all_elements(&modules, m, avl, tmp)
 119                 free(m);
 120 }
 121
 122 static char* get_module_path(char *name)
 123 {
 124         char **p;
 125         static char path[256];
 126         struct stat s;
 127
 128         if (!stat(name, &s) && S_ISREG(s.st_mode))
 129                 return name;
 130
 131         for (p = module_folders; *p; p++) {
 132                 snprintf(path, sizeof(path), "%s%s.ko", *p, name);
 133                 if (!stat(path, &s) && S_ISREG(s.st_mode))
 134                         return path;
 135         }
 136
 137         return NULL;
 138 }
 139
 140 static char* get_module_name(char *path)
 141 {
 142         static char name[32];
 143         char *t;
 144
 145         strncpy(name, basename(path), sizeof(name));
 146
 147         t = strstr(name, ".ko");
 148         if (t)
 149                 *t = '\0';
 150
 151         return name;
 152 }
 153
 154 static int elf64_find_section(char *map, const char *section, unsigned int *offset, unsigned int *size)
 155 {
 156         const char *secnames;
 157         Elf64_Ehdr *e;
 158         Elf64_Shdr *sh;
 159         int i;
 160
 161         e = (Elf64_Ehdr *) map;
 162         sh = (Elf64_Shdr *) (map + e->e_shoff);
 163
 164         secnames = map + sh[e->e_shstrndx].sh_offset;
 165         for (i = 0; i < e->e_shnum; i++) {
 166                 if (!strcmp(section, secnames + sh[i].sh_name)) {
 167                         *size = sh[i].sh_size;
 168                         *offset = sh[i].sh_offset;
 169                         return 0;
 170                 }
 171         }
 172
 173         return -1;
 174 }
 175
 176 static int elf32_find_section(char *map, const char *section, unsigned int *offset, unsigned int *size)
 177 {
 178         const char *secnames;
 179         Elf32_Ehdr *e;
 180         Elf32_Shdr *sh;
 181         int i;
 182
 183         e = (Elf32_Ehdr *) map;
 184         sh = (Elf32_Shdr *) (map + e->e_shoff);
 185
 186         secnames = map + sh[e->e_shstrndx].sh_offset;
 187         for (i = 0; i < e->e_shnum; i++) {
 188                 if (!strcmp(section, secnames + sh[i].sh_name)) {
 189                         *size = sh[i].sh_size;
 190                         *offset = sh[i].sh_offset;
 191                         return 0;
 192                 }
 193         }
 194
 195         return -1;
 196 }
 197
 198 static int elf_find_section(char *map, const char *section, unsigned int *offset, unsigned int *size)
 199 {
 200         int clazz = map[EI_CLASS];
 201
 202         if (clazz == ELFCLASS32)
 203                 return elf32_find_section(map, section, offset, size);
 204         else if (clazz == ELFCLASS64)
 205                 return elf64_find_section(map, section, offset, size);
 206
 207         ULOG_ERR("unknown elf format %d\n", clazz);
 208
 209         return -1;
 210 }
 211
 212 static struct module *
 213 alloc_module(const char *name, const char *depends, int size)
 214 {
 215         struct module *m;
 216         char *_name, *_dep;
 217
 218         m = calloc_a(sizeof(*m),
 219                 &_name, strlen(name) + 1,
 220                 &_dep, depends ? strlen(depends) + 2 : 0);
 221         if (!m)
 222                 return NULL;
 223
 224         m->avl.key = m->name = strcpy(_name, name);
 225         m->opts = 0;
 226
 227         if (depends) {
 228                 m->depends = strcpy(_dep, depends);
 229                 while (*_dep) {
 230                         if (*_dep == ',')
 231                                 *_dep = '\0';
 232                         _dep++;
 233                 }
 234         }
 235
 236         m->size = size;
 237         avl_insert(&modules, &m->avl);
 238
 239         return m;
 240 }
 241
 242 static int scan_loaded_modules(void)
 243 {
 244         size_t buf_len = 0;
 245         char *buf = NULL;
 246         FILE *fp;
 247
 248         fp = fopen("/proc/modules", "r");
 249         if (!fp) {
 250                 ULOG_ERR("failed to open /proc/modules\n");
 251                 return -1;
 252         }
 253
 254         while (getline(&buf, &buf_len, fp) > 0) {
 255                 struct module m;
 256                 struct module *n;
 257
 258                 m.name = strtok(buf, " ");
 259                 m.size = atoi(strtok(NULL, " "));
 260                 m.usage = atoi(strtok(NULL, " "));
 261                 m.depends = strtok(NULL, " ");
 262
 263                 if (!m.name || !m.depends)
 264                         continue;
 265
 266                 n = alloc_module(m.name, m.depends, m.size);
 267                 n->usage = m.usage;
 268                 n->state = LOADED;
 269         }
 270         free(buf);
 271         fclose(fp);
 272
 273         return 0;
 274 }
 275
 276 static struct module* get_module_info(const char *module, const char *name)
 277 {
 278         int fd = open(module, O_RDONLY);
 279         unsigned int offset, size;
 280         char *map = MAP_FAILED, *strings, *dep = NULL;
 281         struct module *m = NULL;
 282         struct stat s;
 283
 284         if (fd < 0) {
 285                 ULOG_ERR("failed to open %s\n", module);
 286                 goto out;
 287         }
 288
 289         if (fstat(fd, &s) == -1) {
 290                 ULOG_ERR("failed to stat %s\n", module);
 291                 goto out;
 292         }
 293
 294         map = mmap(NULL, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 295         if (map == MAP_FAILED) {
 296                 ULOG_ERR("failed to mmap %s\n", module);
 297                 goto out;
 298         }
 299
 300         if (elf_find_section(map, ".modinfo", &offset, &size)) {
 301                 ULOG_ERR("failed to load the .modinfo section from %s\n", module);
 302                 goto out;
 303         }
 304
 305         strings = map + offset;
 306         while (strings && (strings < map + offset + size)) {
 307                 char *sep;
 308                 int len;
 309
 310                 while (!strings[0])
 311                         strings++;
 312                 sep = strstr(strings, "=");
 313                 if (!sep)
 314                         break;
 315                 len = sep - strings;
 316                 sep++;
 317                 if (!strncmp(strings, "depends=", len + 1))
 318                         dep = sep;
 319                 strings = &sep[strlen(sep)];
 320         }
 321
 322         m = alloc_module(name, dep, s.st_size);
 323
 324         if (m)
 325                 m->state = SCANNED;
 326
 327 out:
 328         if (map != MAP_FAILED)
 329                 munmap(map, s.st_size);
 330
 331         if (fd >= 0)
 332                 close(fd);
 333
 334         return m;
 335 }
 336
 337 static int scan_module_folder(const char *dir)
 338 {
 339         int gl_flags = GLOB_NOESCAPE | GLOB_MARK;
 340         struct utsname ver;
 341         char *path;
 342         glob_t gl;
 343         int j;
 344
 345         uname(&ver);
 346         path = alloca(strlen(dir) + sizeof("*.ko") + 1);
 347         sprintf(path, "%s*.ko", dir);
 348
 349         if (glob(path, gl_flags, NULL, &gl) < 0)
 350                 return -1;
 351
 352         for (j = 0; j < gl.gl_pathc; j++) {
 353                 char *name = get_module_name(gl.gl_pathv[j]);
 354                 struct module *m;
 355
 356                 if (!name)
 357                         continue;
 358
 359                 m = find_module(name);
 360                 if (!m)
 361                         get_module_info(gl.gl_pathv[j], name);
 362         }
 363
 364         globfree(&gl);
 365
 366         return 0;
 367 }
 368
 369 static int scan_module_folders(void)
 370 {
 371         int rv = 0;
 372         char **p;
 373
 374         if (init_module_folders())
 375                 return -1;
 376
 377         for (p = module_folders; *p; p++)
 378                 rv |= scan_module_folder(*p);
 379
 380         return rv;
 381 }
 382
 383 static int print_modinfo(char *module)
 384 {
 385         int fd = open(module, O_RDONLY);
 386         unsigned int offset, size;
 387         struct stat s;
 388         char *map = MAP_FAILED, *strings;
 389         int rv = -1;
 390
 391         if (fd < 0) {
 392                 ULOG_ERR("failed to open %s\n", module);
 393                 goto out;
 394         }
 395
 396         if (fstat(fd, &s) == -1) {
 397                 ULOG_ERR("failed to stat %s\n", module);
 398                 goto out;
 399         }
 400
 401         map = mmap(NULL, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 402         if (map == MAP_FAILED) {
 403                 ULOG_ERR("failed to mmap %s\n", module);
 404                 goto out;
 405         }
 406
 407         if (elf_find_section(map, ".modinfo", &offset, &size)) {
 408                 ULOG_ERR("failed to load the .modinfo section from %s\n", module);
 409                 goto out;
 410         }
 411
 412         strings = map + offset;
 413         printf("module:\t\t%s\n", module);
 414         while (strings && (strings < map + offset + size)) {
 415                 char *dup = NULL;
 416                 char *sep;
 417
 418                 while (!strings[0])
 419                         strings++;
 420                 sep = strstr(strings, "=");
 421                 if (!sep)
 422                         break;
 423                 dup = strndup(strings, sep - strings);
 424                 sep++;
 425                 if (strncmp(strings, "parm", 4)) {
 426                         if (strlen(dup) < 7)
 427                                 printf("%s:\t\t%s\n",  dup, sep);
 428                         else
 429                                 printf("%s:\t%s\n",  dup, sep);
 430                 }
 431                 strings = &sep[strlen(sep)];
 432                 if (dup)
 433                         free(dup);
 434         }
 435
 436         rv = 0;
 437
 438 out:
 439         if (map != MAP_FAILED)
 440                 munmap(map, s.st_size);
 441
 442         if (fd >= 0)
 443                 close(fd);
 444
 445         return rv;
 446 }
 447
 448 static int deps_available(struct module *m, int verbose)
 449 {
 450         char *dep;
 451         int err = 0;
 452
 453         if (!m->depends || !strcmp(m->depends, "-") || !strcmp(m->depends, ""))
 454                 return 0;
 455
 456         dep = m->depends;
 457
 458         while (*dep) {
 459                 m = find_module(dep);
 460
 461                 if (verbose && !m)
 462                         ULOG_ERR("missing dependency %s\n", dep);
 463                 if (verbose && m && (m->state != LOADED))
 464                         ULOG_ERR("dependency not loaded %s\n", dep);
 465                 if (!m || (m->state != LOADED))
 466                         err++;
 467                 dep += strlen(dep) + 1;
 468         }
 469
 470         return err;
 471 }
 472
 473 static int insert_module(char *path, const char *options)
 474 {
 475         void *data = 0;
 476         struct stat s;
 477         int fd, ret = -1;
 478
 479         if (stat(path, &s)) {
 480                 ULOG_ERR("missing module %s\n", path);
 481                 return ret;
 482         }
 483
 484         fd = open(path, O_RDONLY);
 485         if (fd < 0) {
 486                 ULOG_ERR("cannot open %s\n", path);
 487                 return ret;
 488         }
 489
 490         data = malloc(s.st_size);
 491         if (read(fd, data, s.st_size) == s.st_size)
 492                 ret = syscall(__NR_init_module, data, (unsigned long) s.st_size, options);
 493         else
 494                 ULOG_ERR("failed to read full module %s\n", path);
 495
 496         close(fd);
 497         free(data);
 498
 499         return ret;
 500 }
 501
 502 static void load_moddeps(struct module *_m)
 503 {
 504         char *dep;
 505         struct module *m;
 506
 507         if (!strcmp(_m->depends, "-") || !strcmp(_m->depends, ""))
 508                 return;
 509
 510         dep = _m->depends;
 511
 512         while (*dep) {
 513                 m = find_module(dep);
 514
 515                 if (!m)
 516                         ULOG_ERR("failed to find dependency %s\n", dep);
 517                 if (m && (m->state != LOADED)) {
 518                         m->state = PROBE;
 519                         load_moddeps(m);
 520                 }
 521
 522                 dep = dep + strlen(dep) + 1;
 523         }
 524 }
 525
 526 static int iterations = 0;
 527 static int load_modprobe(void)
 528 {
 529         int loaded, todo;
 530         struct module *m;
 531
 532         avl_for_each_element(&modules, m, avl)
 533                 if (m->state == PROBE)
 534                         load_moddeps(m);
 535
 536         do {
 537                 loaded = 0;
 538                 todo = 0;
 539                 avl_for_each_element(&modules, m, avl) {
 540                         if ((m->state == PROBE) && (!deps_available(m, 0))) {
 541                                 if (!insert_module(get_module_path(m->name), (m->opts) ? (m->opts) : (""))) {
 542                                         m->state = LOADED;
 543                                         m->error = 0;
 544                                         loaded++;
 545                                         continue;
 546                                 }
 547                                 m->error = 1;
 548                         }
 549
 550                         if ((m->state == PROBE) || m->error)
 551                                 todo++;
 552                 }
 553                 iterations++;
 554         } while (loaded);
 555
 556         return todo;
 557 }
 558
 559 static int print_insmod_usage(void)
 560 {
 561         ULOG_INFO("Usage:\n\tinsmod filename [args]\n");
 562
 563         return -1;
 564 }
 565
 566 static int print_usage(char *arg)
 567 {
 568         ULOG_INFO("Usage:\n\t%s module\n", arg);
 569
 570         return -1;
 571 }
 572
 573 static int main_insmod(int argc, char **argv)
 574 {
 575         char *name, *cur, *options;
 576         int i, ret, len;
 577
 578         if (argc < 2)
 579                 return print_insmod_usage();
 580
 581         name = get_module_name(argv[1]);
 582         if (!name) {
 583                 ULOG_ERR("cannot find module - %s\n", argv[1]);
 584                 return -1;
 585         }
 586
 587         if (scan_loaded_modules())
 588                 return -1;
 589
 590         if (find_module(name)) {
 591                 ULOG_ERR("module is already loaded - %s\n", name);
 592                 return -1;
 593
 594         }
 595
 596         free_modules();
 597
 598         for (len = 0, i = 2; i < argc; i++)
 599                 len += strlen(argv[i]) + 1;
 600
 601         options = malloc(len);
 602         options[0] = 0;
 603         cur = options;
 604         for (i = 2; i < argc; i++) {
 605                 if (options[0]) {
 606                         *cur = ' ';
 607                         cur++;
 608                 }
 609                 cur += sprintf(cur, "%s", argv[i]);
 610         }
 611
 612         if (init_module_folders()) {
 613                 fprintf(stderr, "falied to find the folder holding the modules\n");
 614                 return -1;
 615         }
 616
 617         if (get_module_path(argv[1])) {
 618                 name = argv[1];
 619         } else if (!get_module_path(name)) {
 620                 fprintf(stderr, "Failed to find %s. Maybe it is a built in module ?\n", name);
 621                 return -1;
 622         }
 623
 624         ret = insert_module(get_module_path(name), options);
 625         free(options);
 626
 627         if (ret)
 628                 ULOG_ERR("failed to insert %s\n", get_module_path(name));
 629
 630         return ret;
 631 }
 632
 633 static int main_rmmod(int argc, char **argv)
 634 {
 635         struct module *m;
 636         char *name;
 637         int ret;
 638
 639         if (argc != 2)
 640                 return print_usage("rmmod");
 641
 642         if (scan_loaded_modules())
 643                 return -1;
 644
 645         name = get_module_name(argv[1]);
 646         m = find_module(name);
 647         if (!m) {
 648                 ULOG_ERR("module is not loaded\n");
 649                 return -1;
 650         }
 651         ret = syscall(__NR_delete_module, m->name, 0);
 652
 653         if (ret)
 654                 ULOG_ERR("unloading the module failed\n");
 655
 656         free_modules();
 657
 658         return ret;
 659 }
 660
 661 static int main_lsmod(int argc, char **argv)
 662 {
 663         struct module *m;
 664         char *dep;
 665
 666         if (scan_loaded_modules())
 667                 return -1;
 668
 669         avl_for_each_element(&modules, m, avl)
 670                 if (m->state == LOADED) {
 671                         printf("%-20s%8d%3d ",
 672                                 m->name, m->size, m->usage);
 673                         if (m->depends && strcmp(m->depends, "-") && strcmp(m->depends, "")) {
 674                                 dep = m->depends;
 675                                 while (*dep) {
 676                                         printf("%s", dep);
 677                                         dep = dep + strlen(dep) + 1;
 678                                         if (*dep)
 679                                                 printf(",");
 680                                 }
 681                         }
 682                         printf("\n");
 683                 }
 684
 685         free_modules();
 686
 687         return 0;
 688 }
 689
 690 static int main_modinfo(int argc, char **argv)
 691 {
 692         struct module *m;
 693         char *name;
 694
 695         if (argc != 2)
 696                 return print_usage("modinfo");
 697
 698         if (scan_module_folders())
 699                 return -1;
 700
 701         name = get_module_name(argv[1]);
 702         m = find_module(name);
 703         if (!m) {
 704                 ULOG_ERR("cannot find module - %s\n", argv[1]);
 705                 return -1;
 706         }
 707
 708         name = get_module_path(m->name);
 709         if (!name) {
 710                 ULOG_ERR("cannot find path of module - %s\n", m->name);
 711                 return -1;
 712         }
 713
 714         print_modinfo(name);
 715
 716         return 0;
 717 }
 718
 719 static int main_modprobe(int argc, char **argv)
 720 {
 721         struct module *m;
 722         char *name;
 723
 724         if (argc != 2)
 725                 return print_usage("modprobe");
 726
 727         if (scan_loaded_modules())
 728                 return -1;
 729
 730         if (scan_module_folders())
 731                 return -1;
 732
 733         name = get_module_name(argv[1]);
 734         m = find_module(name);
 735         if (m && m->state == LOADED) {
 736                 ULOG_ERR("%s is already loaded\n", name);
 737                 return -1;
 738         } else if (!m) {
 739                 ULOG_ERR("failed to find a module named %s\n", name);
 740         } else {
 741                 int fail;
 742
 743                 m->state = PROBE;
 744
 745                 fail = load_modprobe();
 746
 747                 if (fail) {
 748                         ULOG_ERR("%d module%s could not be probed\n",
 749                                  fail, (fail == 1) ? ("") : ("s"));
 750
 751                         avl_for_each_element(&modules, m, avl)
 752                                 if ((m->state == PROBE) || m->error)
 753                                         ULOG_ERR("- %s\n", m->name);
 754                 }
 755         }
 756
 757         free_modules();
 758
 759         return 0;
 760 }
 761
 762 static int main_loader(int argc, char **argv)
 763 {
 764         int gl_flags = GLOB_NOESCAPE | GLOB_MARK;
 765         char *dir = "/etc/modules.d/*";
 766         struct module *m;
 767         glob_t gl;
 768         char *path;
 769         int fail, j;
 770
 771         if (argc > 1)
 772                 dir = argv[1];
 773
 774         path = malloc(strlen(dir) + 2);
 775         strcpy(path, dir);
 776         strcat(path, "*");
 777
 778         if (scan_loaded_modules())
 779                 return -1;
 780
 781         if (scan_module_folders())
 782                 return -1;
 783
 784         syslog(LOG_INFO, "kmodloader: loading kernel modules from %s\n", path);
 785
 786         if (glob(path, gl_flags, NULL, &gl) < 0)
 787                 goto out;
 788
 789         for (j = 0; j < gl.gl_pathc; j++) {
 790                 FILE *fp = fopen(gl.gl_pathv[j], "r");
 791                 size_t mod_len = 0;
 792                 char *mod = NULL;
 793
 794                 if (!fp) {
 795                         ULOG_ERR("failed to open %s\n", gl.gl_pathv[j]);
 796                         continue;
 797                 }
 798
 799                 while (getline(&mod, &mod_len, fp) > 0) {
 800                         char *nl = strchr(mod, '\n');
 801                         struct module *m;
 802                         char *opts;
 803
 804                         if (nl)
 805                                 *nl = '\0';
 806
 807                         opts = strchr(mod, ' ');
 808                         if (opts)
 809                                 *opts++ = '\0';
 810
 811                         m = find_module(get_module_name(mod));
 812                         if (!m || (m->state == LOADED))
 813                                 continue;
 814
 815                         if (opts)
 816                                 m->opts = strdup(opts);
 817                         m->state = PROBE;
 818                         if (basename(gl.gl_pathv[j])[0] - '0' <= 9)
 819                                 load_modprobe();
 820
 821                 }
 822                 free(mod);
 823                 fclose(fp);
 824         }
 825
 826         fail = load_modprobe();
 827
 828         if (fail) {
 829                 ULOG_ERR("%d module%s could not be probed\n",
 830                          fail, (fail == 1) ? ("") : ("s"));
 831
 832                 avl_for_each_element(&modules, m, avl)
 833                         if ((m->state == PROBE) || (m->error))
 834                                 ULOG_ERR("- %s - %d\n", m->name, deps_available(m, 1));
 835         }
 836
 837 out:
 838         globfree(&gl);
 839         free(path);
 840
 841         return 0;
 842 }
 843
 844 static int avl_modcmp(const void *k1, const void *k2, void *ptr)
 845 {
 846         const char *s1 = k1;
 847         const char *s2 = k2;
 848
 849         while (*s1 && ((*s1 == *s2) ||
 850                        ((*s1 == '_') && (*s2 == '-')) ||
 851                        ((*s1 == '-') && (*s2 == '_'))))
 852         {
 853                 s1++;
 854                 s2++;
 855         }
 856
 857         return *(const unsigned char *)s1 - *(const unsigned char *)s2;
 858 }
 859
 860 int main(int argc, char **argv)
 861 {
 862         char *exec = basename(*argv);
 863
 864         avl_init(&modules, avl_modcmp, false, NULL);
 865         if (!strcmp(exec, "insmod"))
 866                 return main_insmod(argc, argv);
 867
 868         if (!strcmp(exec, "rmmod"))
 869                 return main_rmmod(argc, argv);
 870
 871         if (!strcmp(exec, "lsmod"))
 872                 return main_lsmod(argc, argv);
 873
 874         if (!strcmp(exec, "modinfo"))
 875                 return main_modinfo(argc, argv);
 876
 877         if (!strcmp(exec, "modprobe"))
 878                 return main_modprobe(argc, argv);
 879
 880         return main_loader(argc, argv);
 881 }