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
  39 #define DEF_MOD_PATH "/lib/modules/%s/"
  40
  41 #define LOG(fmt, ...) do { \
  42         syslog(LOG_INFO, fmt, ## __VA_ARGS__); \
  43         printf("kmod: "fmt, ## __VA_ARGS__); \
  44         } while (0)
  45
  46
  47 enum {
  48         SCANNED,
  49         PROBE,
  50         LOADED,
  51 };
  52
  53 struct module {
  54         struct avl_node avl;
  55
  56         char *name;
  57         char *depends;
  58
  59         int size;
  60         int usage;
  61         int state;
  62         int error;
  63 };
  64
  65 static struct avl_tree modules;
  66 static char *prefix = "";
  67
  68 static struct module *find_module(const char *name)
  69 {
  70         struct module *m;
  71         return avl_find_element(&modules, name, m, avl);
  72 }
  73
  74 static void free_modules(void)
  75 {
  76         struct module *m, *tmp;
  77
  78         avl_remove_all_elements(&modules, m, avl, tmp)
  79                 free(m);
  80 }
  81
  82 static char* get_module_path(char *name)
  83 {
  84         static char path[256];
  85         struct utsname ver;
  86         struct stat s;
  87         char *t;
  88
  89         if (!stat(name, &s))
  90                 return name;
  91
  92         uname(&ver);
  93         snprintf(path, 256, "%s" DEF_MOD_PATH "%s.ko", prefix, ver.release, name);
  94
  95         if (!stat(path, &s))
  96                 return path;
  97
  98         t = name;
  99         while (t && *t) {
 100                 if (*t == '_')
 101                         *t = '-';
 102                 t++;
 103         }
 104
 105         snprintf(path, 256, "%s" DEF_MOD_PATH "%s.ko", prefix, ver.release, name);
 106
 107         if (!stat(path, &s))
 108                 return path;
 109
 110         return NULL;
 111 }
 112
 113 static char* get_module_name(char *path)
 114 {
 115         static char name[32];
 116         char *t;
 117
 118         strncpy(name, basename(path), sizeof(name));
 119
 120         t = strstr(name, ".ko");
 121         if (t)
 122                 *t = '\0';
 123         t = name;
 124         while (t && *t) {
 125                 if (*t == '-')
 126                         *t = '_';
 127                 t++;
 128         }
 129
 130         return name;
 131 }
 132
 133 #if __WORDSIZE == 64
 134 static int elf_find_section(char *map, const char *section, unsigned int *offset, unsigned int *size)
 135 {
 136         const char *secnames;
 137         Elf64_Ehdr *e;
 138         Elf64_Shdr *sh;
 139         int i;
 140
 141         e = (Elf64_Ehdr *) map;
 142         sh = (Elf64_Shdr *) (map + e->e_shoff);
 143
 144         secnames = map + sh[e->e_shstrndx].sh_offset;
 145         for (i = 0; i < e->e_shnum; i++) {
 146                 if (!strcmp(section, secnames + sh[i].sh_name)) {
 147                         *size = sh[i].sh_size;
 148                         *offset = sh[i].sh_offset;
 149                         return 0;
 150                 }
 151         }
 152
 153         return -1;
 154 }
 155 #else
 156 static int elf_find_section(char *map, const char *section, unsigned int *offset, unsigned int *size)
 157 {
 158         const char *secnames;
 159         Elf32_Ehdr *e;
 160         Elf32_Shdr *sh;
 161         int i;
 162
 163         e = (Elf32_Ehdr *) map;
 164         sh = (Elf32_Shdr *) (map + e->e_shoff);
 165
 166         secnames = map + sh[e->e_shstrndx].sh_offset;
 167         for (i = 0; i < e->e_shnum; i++) {
 168                 if (!strcmp(section, secnames + sh[i].sh_name)) {
 169                         *size = sh[i].sh_size;
 170                         *offset = sh[i].sh_offset;
 171                         return 0;
 172                 }
 173         }
 174
 175         return -1;
 176 }
 177 #endif
 178
 179 static struct module *
 180 alloc_module(const char *name, const char *depends, int size)
 181 {
 182         struct module *m;
 183         char *_name, *_dep;
 184
 185         m = calloc_a(sizeof(*m),
 186                 &_name, strlen(name) + 1,
 187                 &_dep, depends ? strlen(depends) + 1 : 0);
 188         if (!m)
 189                 return NULL;
 190
 191         m->avl.key = m->name = strcpy(_name, name);
 192
 193         if (depends)
 194                 m->depends = strcpy(_dep, depends);
 195
 196         m->size = size;
 197         avl_insert(&modules, &m->avl);
 198         return m;
 199 }
 200
 201 static int scan_loaded_modules(void)
 202 {
 203         size_t buf_len = 0;
 204         char *buf = NULL;
 205         FILE *fp;
 206
 207         fp = fopen("/proc/modules", "r");
 208         if (!fp) {
 209                 LOG("failed to open /proc/modules\n");
 210                 return -1;
 211         }
 212
 213         while (getline(&buf, &buf_len, fp) > 0) {
 214                 struct module m;
 215                 struct module *n;
 216
 217                 m.name = strtok(buf, " ");
 218                 m.size = atoi(strtok(NULL, " "));
 219                 m.usage = atoi(strtok(NULL, " "));
 220                 m.depends = strtok(NULL, " ");
 221
 222                 if (!m.name || !m.depends)
 223                         continue;
 224
 225                 n = alloc_module(m.name, m.depends, m.size);
 226                 n->usage = m.usage;
 227                 n->state = LOADED;
 228         }
 229         free(buf);
 230         fclose(fp);
 231
 232         return 0;
 233 }
 234
 235 static struct module* get_module_info(const char *module, const char *name)
 236 {
 237         int fd = open(module, O_RDONLY);
 238         unsigned int offset, size;
 239         char *map, *strings, *dep = NULL;
 240         struct module *m;
 241         struct stat s;
 242
 243         if (!fd) {
 244                 LOG("failed to open %s\n", module);
 245                 return NULL;
 246         }
 247
 248         if (fstat(fd, &s) == -1) {
 249                 LOG("failed to stat %s\n", module);
 250                 return NULL;
 251         }
 252
 253         map = mmap(NULL, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 254         if (map == MAP_FAILED) {
 255                 LOG("failed to mmap %s\n", module);
 256                 return NULL;
 257         }
 258
 259         if (elf_find_section(map, ".modinfo", &offset, &size)) {
 260                 LOG("failed to load the .modinfo section from %s\n", module);
 261                 return NULL;
 262         }
 263
 264         strings = map + offset;
 265         while (strings && (strings < map + offset + size)) {
 266                 char *sep;
 267                 int len;
 268
 269                 while (!strings[0])
 270                         strings++;
 271                 sep = strstr(strings, "=");
 272                 if (!sep)
 273                         break;
 274                 len = sep - strings;
 275                 sep++;
 276                 if (!strncmp(strings, "depends=", len + 1))
 277                         dep = sep;
 278                 strings = &sep[strlen(sep)];
 279         }
 280
 281         m = alloc_module(name, dep, s.st_size);
 282         if (!m)
 283                 return NULL;
 284
 285         m->state = SCANNED;
 286
 287         return m;
 288 }
 289
 290 static int scan_module_folder(void)
 291 {
 292         int gl_flags = GLOB_NOESCAPE | GLOB_MARK;
 293         struct utsname ver;
 294         char *path;
 295         glob_t gl;
 296         int j;
 297
 298         uname(&ver);
 299         path = alloca(sizeof(DEF_MOD_PATH "*.ko") + strlen(ver.release) + 1);
 300         sprintf(path, DEF_MOD_PATH "*.ko", ver.release);
 301
 302         if (glob(path, gl_flags, NULL, &gl) < 0)
 303                 return -1;
 304
 305         for (j = 0; j < gl.gl_pathc; j++) {
 306                 char *name = get_module_name(gl.gl_pathv[j]);
 307                 struct module *m;
 308
 309                 if (!name)
 310                         continue;
 311
 312                 m = find_module(name);
 313                 if (!m)
 314                         get_module_info(gl.gl_pathv[j], name);
 315         }
 316
 317         globfree(&gl);
 318
 319         return 0;
 320 }
 321
 322 static int print_modinfo(char *module)
 323 {
 324         int fd = open(module, O_RDONLY);
 325         unsigned int offset, size;
 326         struct stat s;
 327         char *map, *strings;
 328
 329         if (!fd) {
 330                 LOG("failed to open %s\n", module);
 331                 return -1;
 332         }
 333
 334         if (fstat(fd, &s) == -1) {
 335                 LOG("failed to stat %s\n", module);
 336                 return -1;
 337         }
 338
 339         map = mmap(NULL, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 340         if (map == MAP_FAILED) {
 341                 LOG("failed to mmap %s\n", module);
 342                 return -1;
 343         }
 344
 345         if (elf_find_section(map, ".modinfo", &offset, &size)) {
 346                 LOG("failed to load the .modinfo section from %s\n", module);
 347                 return -1;
 348         }
 349
 350         strings = map + offset;
 351         printf("module:\t\t%s\n", module);
 352         while (strings && (strings < map + offset + size)) {
 353                 char *dup = NULL;
 354                 char *sep;
 355
 356                 while (!strings[0])
 357                         strings++;
 358                 sep = strstr(strings, "=");
 359                 if (!sep)
 360                         break;
 361                 dup = strndup(strings, sep - strings);
 362                 sep++;
 363                 if (strncmp(strings, "parm", 4)) {
 364                         if (strlen(dup) < 7)
 365                                 printf("%s:\t\t%s\n",  dup, sep);
 366                         else
 367                                 printf("%s:\t%s\n",  dup, sep);
 368                 }
 369                 strings = &sep[strlen(sep)];
 370                 if (dup)
 371                         free(dup);
 372         }
 373
 374         return 0;
 375 }
 376
 377 static int deps_available(struct module *m, int verbose)
 378 {
 379         char *deps, *_deps;
 380         char *comma;
 381         int err = 0;
 382
 383         if (!strcmp(m->depends, "-") || !strcmp(m->depends, ""))
 384                 return 0;
 385
 386         _deps = deps = strdup(m->depends);
 387
 388         do {
 389                 comma = strstr(deps, ",");
 390                 if (comma)
 391                         *comma = '\0';
 392
 393                 m = find_module(deps);
 394
 395                 if (verbose && !m)
 396                         LOG("missing dependency %s\n", deps);
 397                 if (verbose && m && (m->state != LOADED))
 398                         LOG("dependency not loaded %s\n", deps);
 399                 if (!m || (m->state != LOADED))
 400                         err++;
 401                 if (comma)
 402                         deps = ++comma;
 403         } while (comma);
 404
 405         free(_deps);
 406
 407         return err;
 408 }
 409
 410 static int insert_module(char *path, const char *options)
 411 {
 412         void *data = 0;
 413         struct stat s;
 414         int fd, ret = -1;
 415
 416         if (stat(path, &s)) {
 417                 LOG("missing module %s\n", path);
 418                 return ret;
 419         }
 420
 421         fd = open(path, O_RDONLY);
 422         if (!fd) {
 423                 LOG("cannot open %s\n", path);
 424                 return ret;
 425         }
 426
 427         data = malloc(s.st_size);
 428         if (read(fd, data, s.st_size) == s.st_size)
 429                 ret = syscall(__NR_init_module, data, s.st_size, options);
 430         else
 431                 LOG("failed to read full module %s\n", path);
 432
 433         close(fd);
 434         free(data);
 435
 436         return ret;
 437 }
 438
 439 static void load_moddeps(struct module *_m)
 440 {
 441         char *deps, *_deps;
 442         struct module *m;
 443         char *comma;
 444
 445         if (!strcmp(_m->depends, "-") || !strcmp(_m->depends, ""))
 446                 return;
 447
 448         _deps = deps = strdup(_m->depends);
 449
 450         do {
 451                 char *t = deps;
 452
 453                 comma = strstr(deps, ",");
 454                 if (comma)
 455                         *comma = '\0';
 456
 457                 m = find_module(deps);
 458
 459                 if (!m) {
 460                         while (t && *t) {
 461                                 if (*t == '-')
 462                                         *t = '_';
 463                                 t++;
 464                         }
 465                         m = find_module(deps);
 466                 }
 467
 468                 if (!m)
 469                         LOG("failed to find dependency %s\n", deps);
 470                 if (m && (m->state != LOADED)) {
 471                         m->state = PROBE;
 472                         load_moddeps(m);
 473                 }
 474
 475                 if (comma)
 476                         deps = ++comma;
 477         } while (comma);
 478
 479         free(_deps);
 480 }
 481
 482 static int load_modprobe(void)
 483 {
 484         int loaded, todo;
 485         struct module *m;
 486
 487         avl_for_each_element(&modules, m, avl)
 488                 if (m->state == PROBE)
 489                         load_moddeps(m);
 490
 491         do {
 492                 loaded = 0;
 493                 todo = 0;
 494                 avl_for_each_element(&modules, m, avl) {
 495                         if ((m->state == PROBE) && (!deps_available(m, 0))) {
 496                                 if (!insert_module(get_module_path(m->name), "")) {
 497                                         m->state = LOADED;
 498                                         m->error = 0;
 499                                         loaded++;
 500                                         continue;
 501                                 }
 502                                 m->error = 1;
 503                         }
 504
 505                         if ((m->state == PROBE) || m->error)
 506                                 todo++;
 507                 }
 508         } while (loaded);
 509
 510         return todo;
 511 }
 512
 513 static int print_insmod_usage(void)
 514 {
 515         LOG("Usage:\n\tinsmod filename [args]\n");
 516
 517         return -1;
 518 }
 519
 520 static int print_usage(char *arg)
 521 {
 522         LOG("Usage:\n\t%s module\n", arg);
 523
 524         return -1;
 525 }
 526
 527 static int main_insmod(int argc, char **argv)
 528 {
 529         char *name, *cur, *options;
 530         int i, ret, len;
 531
 532         if (argc < 2)
 533                 return print_insmod_usage();
 534
 535         name = get_module_name(argv[1]);
 536         if (!name) {
 537                 LOG("cannot find module - %s\n", argv[1]);
 538                 return -1;
 539         }
 540
 541         if (scan_loaded_modules())
 542                 return -1;
 543
 544         if (find_module(name)) {
 545                 LOG("module is already loaded - %s\n", name);
 546                 return -1;
 547
 548         }
 549
 550         free_modules();
 551
 552         for (len = 0, i = 2; i < argc; i++)
 553                 len += strlen(argv[i]) + 1;
 554
 555         options = malloc(len);
 556         options[0] = 0;
 557         cur = options;
 558         for (i = 2; i < argc; i++) {
 559                 if (options[0]) {
 560                         *cur = ' ';
 561                         cur++;
 562                 }
 563                 cur += sprintf(cur, "%s", argv[i]);
 564         }
 565
 566         ret = insert_module(get_module_path(name), options);
 567         free(options);
 568
 569         if (ret)
 570                 LOG("failed to insert %s\n", get_module_path(name));
 571
 572         return ret;
 573 }
 574
 575 static int main_rmmod(int argc, char **argv)
 576 {
 577         struct module *m;
 578         char *name;
 579         int ret;
 580
 581         if (argc != 2)
 582                 return print_usage("rmmod");
 583
 584         if (scan_loaded_modules())
 585                 return -1;
 586
 587         name = get_module_name(argv[1]);
 588         m = find_module(name);
 589         if (!m) {
 590                 LOG("module is not loaded\n");
 591                 return -1;
 592         }
 593         free_modules();
 594
 595         ret = syscall(__NR_delete_module, name, 0);
 596
 597         if (ret)
 598                 LOG("unloading the module failed\n");
 599
 600         return ret;
 601 }
 602
 603 static int main_lsmod(int argc, char **argv)
 604 {
 605         struct module *m;
 606
 607         if (scan_loaded_modules())
 608                 return -1;
 609
 610         avl_for_each_element(&modules, m, avl)
 611                 if (m->state == LOADED)
 612                         printf("%-20s%8d%3d %s\n",
 613                                 m->name, m->size, m->usage,
 614                                 (*m->depends == '-') ? ("") : (m->depends));
 615
 616         free_modules();
 617
 618         return 0;
 619 }
 620
 621 static int main_modinfo(int argc, char **argv)
 622 {
 623         char *module;
 624
 625         if (argc != 2)
 626                 return print_usage("modinfo");
 627
 628         module = get_module_path(argv[1]);
 629         if (!module) {
 630                 LOG("cannot find module - %s\n", argv[1]);
 631                 return -1;
 632         }
 633
 634         print_modinfo(module);
 635
 636         return 0;
 637 }
 638
 639 static int main_modprobe(int argc, char **argv)
 640 {
 641         struct module *m;
 642         char *name;
 643
 644         if (argc != 2)
 645                 return print_usage("modprobe");
 646
 647         if (scan_loaded_modules())
 648                 return -1;
 649
 650         if (scan_module_folder())
 651                 return -1;
 652
 653         name = get_module_name(argv[1]);
 654         m = find_module(name);
 655         if (m && m->state == LOADED) {
 656                 LOG("%s is already loaded\n", name);
 657                 return -1;
 658         } else if (!m) {
 659                 LOG("failed to find a module named %s\n", name);
 660         } else {
 661                 int fail;
 662
 663                 m->state = PROBE;
 664
 665                 fail = load_modprobe();
 666
 667                 if (fail) {
 668                         LOG("%d module%s could not be probed\n",
 669                                         fail, (fail == 1) ? ("") : ("s"));
 670
 671                         avl_for_each_element(&modules, m, avl)
 672                                 if ((m->state == PROBE) || m->error)
 673                                         LOG("- %s\n", m->name);
 674                 }
 675         }
 676
 677         free_modules();
 678
 679         return 0;
 680 }
 681
 682 static int main_loader(int argc, char **argv)
 683 {
 684         int gl_flags = GLOB_NOESCAPE | GLOB_MARK;
 685         char *dir = "/etc/modules.d/*";
 686         struct module *m;
 687         glob_t gl;
 688         char *path;
 689         int fail, j;
 690
 691         if (argc > 1)
 692                 dir = argv[1];
 693
 694         if (argc > 2)
 695                 prefix = argv[2];
 696
 697         path = malloc(strlen(dir) + 2);
 698         strcpy(path, dir);
 699         strcat(path, "*");
 700
 701         if (scan_loaded_modules())
 702                 return -1;
 703
 704         if (scan_module_folder())
 705                 return -1;
 706
 707         syslog(0, "kmodloader: loading kernel modules from %s\n", path);
 708
 709         if (glob(path, gl_flags, NULL, &gl) < 0)
 710                 goto out;
 711
 712         for (j = 0; j < gl.gl_pathc; j++) {
 713                 FILE *fp = fopen(gl.gl_pathv[j], "r");
 714                 size_t mod_len = 0;
 715                 char *mod = NULL;
 716
 717                 if (!fp) {
 718                         LOG("failed to open %s\n", gl.gl_pathv[j]);
 719                         continue;
 720                 }
 721
 722                 while (getline(&mod, &mod_len, fp) > 0) {
 723                         char *nl = strchr(mod, '\n');
 724                         struct module *m;
 725                         char *opts;
 726
 727                         if (nl)
 728                                 *nl = '\0';
 729
 730                         opts = strchr(mod, ' ');
 731                         if (opts)
 732                                 *opts++ = '\0';
 733
 734                         m = find_module(get_module_name(mod));
 735                         if (!m || (m->state == LOADED))
 736                                 continue;
 737
 738                         m->state = PROBE;
 739                         if (basename(gl.gl_pathv[j])[0] - '0' <= 9)
 740                                 load_modprobe();
 741
 742                 }
 743                 free(mod);
 744                 fclose(fp);
 745         }
 746
 747         fail = load_modprobe();
 748
 749         if (fail) {
 750                 LOG("%d module%s could not be probed\n",
 751                                 fail, (fail == 1) ? ("") : ("s"));
 752
 753                 avl_for_each_element(&modules, m, avl)
 754                         if ((m->state == PROBE) || (m->error))
 755                                 LOG("- %s - %d\n", m->name, deps_available(m, 1));
 756         }
 757
 758 out:
 759         globfree(&gl);
 760         free(path);
 761
 762         return 0;
 763 }
 764
 765 int main(int argc, char **argv)
 766 {
 767         char *exec = basename(*argv);
 768
 769         avl_init(&modules, avl_strcmp, false, NULL);
 770         if (!strcmp(exec, "insmod"))
 771                 return main_insmod(argc, argv);
 772
 773         if (!strcmp(exec, "rmmod"))
 774                 return main_rmmod(argc, argv);
 775
 776         if (!strcmp(exec, "lsmod"))
 777                 return main_lsmod(argc, argv);
 778
 779         if (!strcmp(exec, "modinfo"))
 780                 return main_modinfo(argc, argv);
 781
 782         if (!strcmp(exec, "modprobe"))
 783                 return main_modprobe(argc, argv);
 784
 785         return main_loader(argc, argv);
 786 }