release/src/router/busybox/modutils/modprobe-small.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * simplified modprobe
   4  *
   5  * Copyright (c) 2008 Vladimir Dronnikov
   6  * Copyright (c) 2008 Bernhard Reutner-Fischer (initial depmod code)
   7  *
   8  * Licensed under GPLv2, see file LICENSE in this tarball for details.
   9  */
  10
  11 #include "libbb.h"
  12
  13 #include <sys/utsname.h> /* uname() */
  14 #include <fnmatch.h>
  15
  16 extern int init_module(void *module, unsigned long len, const char *options);
  17 extern int delete_module(const char *module, unsigned flags);
  18 extern int query_module(const char *name, int which, void *buf, size_t bufsize, size_t *ret);
  19
  20
  21 #define dbg1_error_msg(...) ((void)0)
  22 #define dbg2_error_msg(...) ((void)0)
  23 //#define dbg1_error_msg(...) bb_error_msg(__VA_ARGS__)
  24 //#define dbg2_error_msg(...) bb_error_msg(__VA_ARGS__)
  25
  26 #define DEPFILE_BB CONFIG_DEFAULT_DEPMOD_FILE".bb"
  27
  28 enum {
  29         OPT_q = (1 << 0), /* be quiet */
  30         OPT_r = (1 << 1), /* module removal instead of loading */
  31 };
  32
  33 typedef struct module_info {
  34         char *pathname;
  35         char *aliases;
  36         char *deps;
  37 } module_info;
  38
  39 /*
  40  * GLOBALS
  41  */
  42 struct globals {
  43         module_info *modinfo;
  44         char *module_load_options;
  45         smallint dep_bb_seen;
  46         smallint wrote_dep_bb_ok;
  47         int module_count;
  48         int module_found_idx;
  49         int stringbuf_idx;
  50         char stringbuf[32 * 1024]; /* some modules have lots of stuff */
  51         /* for example, drivers/media/video/saa7134/saa7134.ko */
  52 };
  53 #define G (*ptr_to_globals)
  54 #define modinfo             (G.modinfo            )
  55 #define dep_bb_seen         (G.dep_bb_seen        )
  56 #define wrote_dep_bb_ok     (G.wrote_dep_bb_ok    )
  57 #define module_count        (G.module_count       )
  58 #define module_found_idx    (G.module_found_idx   )
  59 #define module_load_options (G.module_load_options)
  60 #define stringbuf_idx       (G.stringbuf_idx      )
  61 #define stringbuf           (G.stringbuf          )
  62 #define INIT_G() do { \
  63         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
  64 } while (0)
  65
  66
  67 static void appendc(char c)
  68 {
  69         if (stringbuf_idx < sizeof(stringbuf))
  70                 stringbuf[stringbuf_idx++] = c;
  71 }
  72
  73 static void bksp(void)
  74 {
  75         if (stringbuf_idx)
  76                 stringbuf_idx--;
  77 }
  78
  79 static void append(const char *s)
  80 {
  81         size_t len = strlen(s);
  82         if (stringbuf_idx + len < sizeof(stringbuf)) {
  83                 memcpy(stringbuf + stringbuf_idx, s, len);
  84                 stringbuf_idx += len;
  85         }
  86 }
  87
  88 static void reset_stringbuf(void)
  89 {
  90         stringbuf_idx = 0;
  91 }
  92
  93 static char* copy_stringbuf(void)
  94 {
  95         char *copy = xmalloc(stringbuf_idx);
  96         return memcpy(copy, stringbuf, stringbuf_idx);
  97 }
  98
  99 static char* find_keyword(char *ptr, size_t len, const char *word)
 100 {
 101         int wlen;
 102
 103         if (!ptr) /* happens if xmalloc_open_zipped_read_close cannot read it */
 104                 return NULL;
 105
 106         wlen = strlen(word);
 107         len -= wlen - 1;
 108         while ((ssize_t)len > 0) {
 109                 char *old = ptr;
 110                 /* search for the first char in word */
 111                 ptr = memchr(ptr, *word, len);
 112                 if (ptr == NULL) /* no occurance left, done */
 113                         break;
 114                 if (strncmp(ptr, word, wlen) == 0)
 115                         return ptr + wlen; /* found, return ptr past it */
 116                 ++ptr;
 117                 len -= (ptr - old);
 118         }
 119         return NULL;
 120 }
 121
 122 static void replace(char *s, char what, char with)
 123 {
 124         while (*s) {
 125                 if (what == *s)
 126                         *s = with;
 127                 ++s;
 128         }
 129 }
 130
 131 /* Take "word word", return malloced "word",NUL,"word",NUL,NUL */
 132 static char* str_2_list(const char *str)
 133 {
 134         int len = strlen(str) + 1;
 135         char *dst = xmalloc(len + 1);
 136
 137         dst[len] = '\0';
 138         memcpy(dst, str, len);
 139 //TODO: protect against 2+ spaces: "word  word"
 140         replace(dst, ' ', '\0');
 141         return dst;
 142 }
 143
 144 /* We use error numbers in a loose translation... */
 145 static const char *moderror(int err)
 146 {
 147         switch (err) {
 148         case ENOEXEC:
 149                 return "invalid module format";
 150         case ENOENT:
 151                 return "unknown symbol in module or invalid parameter";
 152         case ESRCH:
 153                 return "module has wrong symbol version";
 154         case EINVAL: /* "invalid parameter" */
 155                 return "unknown symbol in module or invalid parameter"
 156                 + sizeof("unknown symbol in module or");
 157         default:
 158                 return strerror(err);
 159         }
 160 }
 161
 162 static int load_module(const char *fname, const char *options)
 163 {
 164 #if 1
 165         int r;
 166         size_t len = MAXINT(ssize_t);
 167         char *module_image;
 168         dbg1_error_msg("load_module('%s','%s')", fname, options);
 169
 170         module_image = xmalloc_open_zipped_read_close(fname, &len);
 171         r = (!module_image || init_module(module_image, len, options ? options : "") != 0);
 172         free(module_image);
 173         dbg1_error_msg("load_module:%d", r);
 174         return r; /* 0 = success */
 175 #else
 176         /* For testing */
 177         dbg1_error_msg("load_module('%s','%s')", fname, options);
 178         return 1;
 179 #endif
 180 }
 181
 182 static void parse_module(module_info *info, const char *pathname)
 183 {
 184         char *module_image;
 185         char *ptr;
 186         size_t len;
 187         size_t pos;
 188         dbg1_error_msg("parse_module('%s')", pathname);
 189
 190         /* Read (possibly compressed) module */
 191         len = 64 * 1024 * 1024; /* 64 Mb at most */
 192         module_image = xmalloc_open_zipped_read_close(pathname, &len);
 193 //TODO: optimize redundant module body reads
 194
 195         /* "alias1 symbol:sym1 alias2 symbol:sym2" */
 196         reset_stringbuf();
 197         pos = 0;
 198         while (1) {
 199                 ptr = find_keyword(module_image + pos, len - pos, "alias=");
 200                 if (!ptr) {
 201                         ptr = find_keyword(module_image + pos, len - pos, "__ksymtab_");
 202                         if (!ptr)
 203                                 break;
 204                         /* DOCME: __ksymtab_gpl and __ksymtab_strings occur
 205                          * in many modules. What do they mean? */
 206                         if (strcmp(ptr, "gpl") == 0 || strcmp(ptr, "strings") == 0)
 207                                 goto skip;
 208                         dbg2_error_msg("alias:'symbol:%s'", ptr);
 209                         append("symbol:");
 210                 } else {
 211                         dbg2_error_msg("alias:'%s'", ptr);
 212                 }
 213                 append(ptr);
 214                 appendc(' ');
 215  skip:
 216                 pos = (ptr - module_image);
 217         }
 218         bksp(); /* remove last ' ' */
 219         appendc('\0');
 220         info->aliases = copy_stringbuf();
 221         replace(info->aliases, '-', '_');
 222
 223         /* "dependency1 depandency2" */
 224         reset_stringbuf();
 225         ptr = find_keyword(module_image, len, "depends=");
 226         if (ptr && *ptr) {
 227                 replace(ptr, ',', ' ');
 228                 replace(ptr, '-', '_');
 229                 dbg2_error_msg("dep:'%s'", ptr);
 230                 append(ptr);
 231         }
 232         appendc('\0');
 233         info->deps = copy_stringbuf();
 234
 235         free(module_image);
 236 }
 237
 238 static int pathname_matches_modname(const char *pathname, const char *modname)
 239 {
 240         const char *fname = bb_get_last_path_component_nostrip(pathname);
 241         const char *suffix = strrstr(fname, ".ko");
 242 //TODO: can do without malloc?
 243         char *name = xstrndup(fname, suffix - fname);
 244         int r;
 245         replace(name, '-', '_');
 246         r = (strcmp(name, modname) == 0);
 247         free(name);
 248         return r;
 249 }
 250
 251 static FAST_FUNC int fileAction(const char *pathname,
 252                 struct stat *sb UNUSED_PARAM,
 253                 void *modname_to_match,
 254                 int depth UNUSED_PARAM)
 255 {
 256         int cur;
 257         const char *fname;
 258
 259         pathname += 2; /* skip "./" */
 260         fname = bb_get_last_path_component_nostrip(pathname);
 261         if (!strrstr(fname, ".ko")) {
 262                 dbg1_error_msg("'%s' is not a module", pathname);
 263                 return TRUE; /* not a module, continue search */
 264         }
 265
 266         cur = module_count++;
 267         modinfo = xrealloc_vector(modinfo, 12, cur);
 268         modinfo[cur].pathname = xstrdup(pathname);
 269         /*modinfo[cur].aliases = NULL; - xrealloc_vector did it */
 270         /*modinfo[cur+1].pathname = NULL;*/
 271
 272         if (!pathname_matches_modname(fname, modname_to_match)) {
 273                 dbg1_error_msg("'%s' module name doesn't match", pathname);
 274                 return TRUE; /* module name doesn't match, continue search */
 275         }
 276
 277         dbg1_error_msg("'%s' module name matches", pathname);
 278         module_found_idx = cur;
 279         parse_module(&modinfo[cur], pathname);
 280
 281         if (!(option_mask32 & OPT_r)) {
 282                 if (load_module(pathname, module_load_options) == 0) {
 283                         /* Load was successful, there is nothing else to do.
 284                          * This can happen ONLY for "top-level" module load,
 285                          * not a dep, because deps dont do dirscan. */
 286                         exit(EXIT_SUCCESS);
 287                 }
 288         }
 289
 290         return TRUE;
 291 }
 292
 293 static int load_dep_bb(void)
 294 {
 295         char *line;
 296         FILE *fp = fopen_for_read(DEPFILE_BB);
 297
 298         if (!fp)
 299                 return 0;
 300
 301         dep_bb_seen = 1;
 302         dbg1_error_msg("loading "DEPFILE_BB);
 303
 304         /* Why? There is a rare scenario: we did not find modprobe.dep.bb,
 305          * we scanned the dir and found no module by name, then we search
 306          * for alias (full scan), and we decided to generate modprobe.dep.bb.
 307          * But we see modprobe.dep.bb.new! Other modprobe is at work!
 308          * We wait and other modprobe renames it to modprobe.dep.bb.
 309          * Now we can use it.
 310          * But we already have modinfo[] filled, and "module_count = 0"
 311          * makes us start anew. Yes, we leak modinfo[].xxx pointers -
 312          * there is not much of data there anyway. */
 313         module_count = 0;
 314         memset(&modinfo[0], 0, sizeof(modinfo[0]));
 315
 316         while ((line = xmalloc_fgetline(fp)) != NULL) {
 317                 char* space;
 318                 int cur;
 319
 320                 if (!line[0]) {
 321                         free(line);
 322                         continue;
 323                 }
 324                 space = strchrnul(line, ' ');
 325                 cur = module_count++;
 326                 modinfo = xrealloc_vector(modinfo, 12, cur);
 327                 /*modinfo[cur+1].pathname = NULL; - xrealloc_vector did it */
 328                 modinfo[cur].pathname = line; /* we take ownership of malloced block here */
 329                 if (*space)
 330                         *space++ = '\0';
 331                 modinfo[cur].aliases = space;
 332                 modinfo[cur].deps = xmalloc_fgetline(fp) ? : xzalloc(1);
 333                 if (modinfo[cur].deps[0]) {
 334                         /* deps are not "", so next line must be empty */
 335                         line = xmalloc_fgetline(fp);
 336                         /* Refuse to work with damaged config file */
 337                         if (line && line[0])
 338                                 bb_error_msg_and_die("error in %s at '%s'", DEPFILE_BB, line);
 339                         free(line);
 340                 }
 341         }
 342         return 1;
 343 }
 344
 345 static int start_dep_bb_writeout(void)
 346 {
 347         int fd;
 348
 349         /* depmod -n: write result to stdout */
 350         if (applet_name[0] == 'd' && (option_mask32 & 1))
 351                 return STDOUT_FILENO;
 352
 353         fd = open(DEPFILE_BB".new", O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 0644);
 354         if (fd < 0) {
 355                 if (errno == EEXIST) {
 356                         int count = 5 * 20;
 357                         dbg1_error_msg(DEPFILE_BB".new exists, waiting for "DEPFILE_BB);
 358                         while (1) {
 359                                 usleep(1000*1000 / 20);
 360                                 if (load_dep_bb()) {
 361                                         dbg1_error_msg(DEPFILE_BB" appeared");
 362                                         return -2; /* magic number */
 363                                 }
 364                                 if (!--count)
 365                                         break;
 366                         }
 367                         bb_error_msg("deleting stale %s", DEPFILE_BB".new");
 368                         fd = open_or_warn(DEPFILE_BB".new", O_WRONLY | O_CREAT | O_TRUNC);
 369                 }
 370         }
 371         dbg1_error_msg("opened "DEPFILE_BB".new:%d", fd);
 372         return fd;
 373 }
 374
 375 static void write_out_dep_bb(int fd)
 376 {
 377         int i;
 378         FILE *fp;
 379
 380         /* We want good error reporting. fdprintf is not good enough. */
 381         fp = fdopen(fd, "w");
 382         if (!fp) {
 383                 close(fd);
 384                 goto err;
 385         }
 386         i = 0;
 387         while (modinfo[i].pathname) {
 388                 fprintf(fp, "%s%s%s\n" "%s%s\n",
 389                         modinfo[i].pathname, modinfo[i].aliases[0] ? " " : "", modinfo[i].aliases,
 390                         modinfo[i].deps, modinfo[i].deps[0] ? "\n" : "");
 391                 i++;
 392         }
 393         /* Badly formatted depfile is a no-no. Be paranoid. */
 394         errno = 0;
 395         if (ferror(fp) | fclose(fp)) /* | instead of || is intended */
 396                 goto err;
 397
 398         if (fd == STDOUT_FILENO) /* it was depmod -n */
 399                 goto ok;
 400
 401         if (rename(DEPFILE_BB".new", DEPFILE_BB) != 0) {
 402  err:
 403                 bb_perror_msg("can't create %s", DEPFILE_BB);
 404                 unlink(DEPFILE_BB".new");
 405         } else {
 406  ok:
 407                 wrote_dep_bb_ok = 1;
 408                 dbg1_error_msg("created "DEPFILE_BB);
 409         }
 410 }
 411
 412 static module_info* find_alias(const char *alias)
 413 {
 414         int i;
 415         int dep_bb_fd;
 416         module_info *result;
 417         dbg1_error_msg("find_alias('%s')", alias);
 418
 419  try_again:
 420         /* First try to find by name (cheaper) */
 421         i = 0;
 422         while (modinfo[i].pathname) {
 423                 if (pathname_matches_modname(modinfo[i].pathname, alias)) {
 424                         dbg1_error_msg("found '%s' in module '%s'",
 425                                         alias, modinfo[i].pathname);
 426                         if (!modinfo[i].aliases) {
 427                                 parse_module(&modinfo[i], modinfo[i].pathname);
 428                         }
 429                         return &modinfo[i];
 430                 }
 431                 i++;
 432         }
 433
 434         /* Ok, we definitely have to scan module bodies. This is a good
 435          * moment to generate modprobe.dep.bb, if it does not exist yet */
 436         dep_bb_fd = dep_bb_seen ? -1 : start_dep_bb_writeout();
 437         if (dep_bb_fd == -2) /* modprobe.dep.bb appeared? */
 438                 goto try_again;
 439
 440         /* Scan all module bodies, extract modinfo (it contains aliases) */
 441         i = 0;
 442         result = NULL;
 443         while (modinfo[i].pathname) {
 444                 char *desc, *s;
 445                 if (!modinfo[i].aliases) {
 446                         parse_module(&modinfo[i], modinfo[i].pathname);
 447                 }
 448                 if (result) {
 449                         i++;
 450                         continue;
 451                 }
 452                 /* "alias1 symbol:sym1 alias2 symbol:sym2" */
 453                 desc = str_2_list(modinfo[i].aliases);
 454                 /* Does matching substring exist? */
 455                 for (s = desc; *s; s += strlen(s) + 1) {
 456                         /* Aliases in module bodies can be defined with
 457                          * shell patterns. Example:
 458                          * "pci:v000010DEd000000D9sv*sd*bc*sc*i*".
 459                          * Plain strcmp() won't catch that */
 460                         if (fnmatch(s, alias, 0) == 0) {
 461                                 dbg1_error_msg("found alias '%s' in module '%s'",
 462                                                 alias, modinfo[i].pathname);
 463                                 result = &modinfo[i];
 464                                 break;
 465                         }
 466                 }
 467                 free(desc);
 468                 if (result && dep_bb_fd < 0)
 469                         return result;
 470                 i++;
 471         }
 472
 473         /* Create module.dep.bb if needed */
 474         if (dep_bb_fd >= 0) {
 475                 write_out_dep_bb(dep_bb_fd);
 476         }
 477
 478         dbg1_error_msg("find_alias '%s' returns %p", alias, result);
 479         return result;
 480 }
 481
 482 #if ENABLE_FEATURE_MODPROBE_SMALL_CHECK_ALREADY_LOADED
 483 // TODO: open only once, invent config_rewind()
 484 static int already_loaded(const char *name)
 485 {
 486         int ret = 0;
 487         char *s;
 488         parser_t *parser = config_open2("/proc/modules", xfopen_for_read);
 489         while (config_read(parser, &s, 1, 1, "# \t", PARSE_NORMAL & ~PARSE_GREEDY)) {
 490                 if (strcmp(s, name) == 0) {
 491                         ret = 1;
 492                         break;
 493                 }
 494         }
 495         config_close(parser);
 496         return ret;
 497 }
 498 #else
 499 #define already_loaded(name) is_rmmod
 500 #endif
 501
 502 /*
 503  * Given modules definition and module name (or alias, or symbol)
 504  * load/remove the module respecting dependencies.
 505  * NB: also called by depmod with bogus name "/",
 506  * just in order to force modprobe.dep.bb creation.
 507 */
 508 #if !ENABLE_FEATURE_MODPROBE_SMALL_OPTIONS_ON_CMDLINE
 509 #define process_module(a,b) process_module(a)
 510 #define cmdline_options ""
 511 #endif
 512 static void process_module(char *name, const char *cmdline_options)
 513 {
 514         char *s, *deps, *options;
 515         module_info *info;
 516         int is_rmmod = (option_mask32 & OPT_r) != 0;
 517         dbg1_error_msg("process_module('%s','%s')", name, cmdline_options);
 518
 519         replace(name, '-', '_');
 520
 521         dbg1_error_msg("already_loaded:%d is_rmmod:%d", already_loaded(name), is_rmmod);
 522         if (already_loaded(name) != is_rmmod) {
 523                 dbg1_error_msg("nothing to do for '%s'", name);
 524                 return;
 525         }
 526
 527         options = NULL;
 528         if (!is_rmmod) {
 529                 char *opt_filename = xasprintf("/etc/modules/%s", name);
 530                 options = xmalloc_open_read_close(opt_filename, NULL);
 531                 if (options)
 532                         replace(options, '\n', ' ');
 533 #if ENABLE_FEATURE_MODPROBE_SMALL_OPTIONS_ON_CMDLINE
 534                 if (cmdline_options) {
 535                         /* NB: cmdline_options always have one leading ' '
 536                          * (see main()), we remove it here */
 537                         char *op = xasprintf(options ? "%s %s" : "%s %s" + 3,
 538                                                 cmdline_options + 1, options);
 539                         free(options);
 540                         options = op;
 541                 }
 542 #endif
 543                 free(opt_filename);
 544                 module_load_options = options;
 545                 dbg1_error_msg("process_module('%s'): options:'%s'", name, options);
 546         }
 547
 548         if (!module_count) {
 549                 /* Scan module directory. This is done only once.
 550                  * It will attempt module load, and will exit(EXIT_SUCCESS)
 551                  * on success. */
 552                 module_found_idx = -1;
 553                 recursive_action(".",
 554                         ACTION_RECURSE, /* flags */
 555                         fileAction, /* file action */
 556                         NULL, /* dir action */
 557                         name, /* user data */
 558                         0); /* depth */
 559                 dbg1_error_msg("dirscan complete");
 560                 /* Module was not found, or load failed, or is_rmmod */
 561                 if (module_found_idx >= 0) { /* module was found */
 562                         info = &modinfo[module_found_idx];
 563                 } else { /* search for alias, not a plain module name */
 564                         info = find_alias(name);
 565                 }
 566         } else {
 567                 info = find_alias(name);
 568         }
 569
 570         /* rmmod? unload it by name */
 571         if (is_rmmod) {
 572                 if (delete_module(name, O_NONBLOCK | O_EXCL) != 0
 573                  && !(option_mask32 & OPT_q)
 574                 ) {
 575                         bb_perror_msg("remove '%s'", name);
 576                         goto ret;
 577                 }
 578                 /* N.B. we do not stop here -
 579                  * continue to unload modules on which the module depends:
 580                  * "-r --remove: option causes modprobe to remove a module.
 581                  * If the modules it depends on are also unused, modprobe
 582                  * will try to remove them, too." */
 583         }
 584
 585         if (!info) {
 586                 /* both dirscan and find_alias found nothing */
 587                 if (applet_name[0] != 'd') /* it wasn't depmod */
 588                         bb_error_msg("module '%s' not found", name);
 589 //TODO: _and_die()?
 590                 goto ret;
 591         }
 592
 593         /* Iterate thru dependencies, trying to (un)load them */
 594         deps = str_2_list(info->deps);
 595         for (s = deps; *s; s += strlen(s) + 1) {
 596                 //if (strcmp(name, s) != 0) // N.B. do loops exist?
 597                 dbg1_error_msg("recurse on dep '%s'", s);
 598                 process_module(s, NULL);
 599                 dbg1_error_msg("recurse on dep '%s' done", s);
 600         }
 601         free(deps);
 602
 603         /* modprobe -> load it */
 604         if (!is_rmmod) {
 605                 if (!options || strstr(options, "blacklist") == NULL) {
 606                         errno = 0;
 607                         if (load_module(info->pathname, options) != 0) {
 608                                 if (EEXIST != errno) {
 609                                         bb_error_msg("'%s': %s",
 610                                                 info->pathname,
 611                                                 moderror(errno));
 612                                 } else {
 613                                         dbg1_error_msg("'%s': %s",
 614                                                 info->pathname,
 615                                                 moderror(errno));
 616                                 }
 617                         }
 618                 } else {
 619                         dbg1_error_msg("'%s': blacklisted", info->pathname);
 620                 }
 621         }
 622  ret:
 623         free(options);
 624 //TODO: return load attempt result from process_module.
 625 //If dep didn't load ok, continuing makes little sense.
 626 }
 627 #undef cmdline_options
 628
 629
 630 /* For reference, module-init-tools v3.4 options:
 631
 632 # insmod
 633 Usage: insmod filename [args]
 634
 635 # rmmod --help
 636 Usage: rmmod [-fhswvV] modulename ...
 637  -f (or --force) forces a module unload, and may crash your
 638     machine. This requires the Forced Module Removal option
 639     when the kernel was compiled.
 640  -h (or --help) prints this help text
 641  -s (or --syslog) says use syslog, not stderr
 642  -v (or --verbose) enables more messages
 643  -V (or --version) prints the version code
 644  -w (or --wait) begins module removal even if it is used
 645     and will stop new users from accessing the module (so it
 646     should eventually fall to zero).
 647
 648 # modprobe
 649 Usage: modprobe [-v] [-V] [-C config-file] [-n] [-i] [-q] [-b]
 650     [-o <modname>] [ --dump-modversions ] <modname> [parameters...]
 651 modprobe -r [-n] [-i] [-v] <modulename> ...
 652 modprobe -l -t <dirname> [ -a <modulename> ...]
 653
 654 # depmod --help
 655 depmod 3.4 -- part of module-init-tools
 656 depmod -[aA] [-n -e -v -q -V -r -u]
 657       [-b basedirectory] [forced_version]
 658 depmod [-n -e -v -q -r -u] [-F kernelsyms] module1.ko module2.ko ...
 659 If no arguments (except options) are given, "depmod -a" is assumed.
 660 depmod will output a dependency list suitable for the modprobe utility.
 661 Options:
 662     -a, --all           Probe all modules
 663     -A, --quick         Only does the work if there's a new module
 664     -n, --show          Write the dependency file on stdout only
 665     -e, --errsyms       Report not supplied symbols
 666     -V, --version       Print the release version
 667     -v, --verbose       Enable verbose mode
 668     -h, --help          Print this usage message
 669 The following options are useful for people managing distributions:
 670     -b basedirectory
 671     --basedir basedirectory
 672                         Use an image of a module tree
 673     -F kernelsyms
 674     --filesyms kernelsyms
 675                         Use the file instead of the current kernel symbols
 676 */
 677
 678 int modprobe_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 679 int modprobe_main(int argc UNUSED_PARAM, char **argv)
 680 {
 681         struct utsname uts;
 682         char applet0 = applet_name[0];
 683         USE_FEATURE_MODPROBE_SMALL_OPTIONS_ON_CMDLINE(char *options;)
 684
 685         /* are we lsmod? -> just dump /proc/modules */
 686         if ('l' == applet0) {
 687                 xprint_and_close_file(xfopen_for_read("/proc/modules"));
 688                 return EXIT_SUCCESS;
 689         }
 690
 691         INIT_G();
 692
 693         /* Prevent ugly corner cases with no modules at all */
 694         modinfo = xzalloc(sizeof(modinfo[0]));
 695
 696         if ('i' != applet0) { /* not insmod */
 697                 /* Goto modules directory */
 698                 xchdir(CONFIG_DEFAULT_MODULES_DIR);
 699         }
 700         uname(&uts); /* never fails */
 701
 702         /* depmod? */
 703         if ('d' == applet0) {
 704                 /* Supported:
 705                  * -n: print result to stdout
 706                  * -a: process all modules (default)
 707                  * optional VERSION parameter
 708                  * Ignored:
 709                  * -A: do work only if a module is newer than depfile
 710                  * -e: report any symbols which a module needs
 711                  *  which are not supplied by other modules or the kernel
 712                  * -F FILE: System.map (symbols for -e)
 713                  * -q, -r, -u: noop?
 714                  * Not supported:
 715                  * -b BASEDIR: (TODO!) modules are in
 716                  *  $BASEDIR/lib/modules/$VERSION
 717                  * -v: human readable deps to stdout
 718                  * -V: version (don't want to support it - people may depend
 719                  *  on it as an indicator of "standard" depmod)
 720                  * -h: help (well duh)
 721                  * module1.o module2.o parameters (just ignored for now)
 722                  */
 723                 getopt32(argv, "na" "AeF:qru" /* "b:vV", NULL */, NULL);
 724                 argv += optind;
 725                 /* if (argv[0] && argv[1]) bb_show_usage(); */
 726                 /* Goto $VERSION directory */
 727                 xchdir(argv[0] ? argv[0] : uts.release);
 728                 /* Force full module scan by asking to find a bogus module.
 729                  * This will generate modules.dep.bb as a side effect. */
 730                 process_module((char*)"/", NULL);
 731                 return !wrote_dep_bb_ok;
 732         }
 733
 734         /* insmod, modprobe, rmmod require at least one argument */
 735         opt_complementary = "-1";
 736         /* only -q (quiet) and -r (rmmod),
 737          * the rest are accepted and ignored (compat) */
 738         getopt32(argv, "qrfsvw");
 739         argv += optind;
 740
 741         /* are we rmmod? -> simulate modprobe -r */
 742         if ('r' == applet0) {
 743                 option_mask32 |= OPT_r;
 744         }
 745
 746         if ('i' != applet0) { /* not insmod */
 747                 /* Goto $VERSION directory */
 748                 xchdir(uts.release);
 749         }
 750
 751 #if ENABLE_FEATURE_MODPROBE_SMALL_OPTIONS_ON_CMDLINE
 752         /* If not rmmod, parse possible module options given on command line.
 753          * insmod/modprobe takes one module name, the rest are parameters. */
 754         options = NULL;
 755         if ('r' != applet0) {
 756                 char **arg = argv;
 757                 while (*++arg) {
 758                         /* Enclose options in quotes */
 759                         char *s = options;
 760                         options = xasprintf("%s \"%s\"", s ? s : "", *arg);
 761                         free(s);
 762                         *arg = NULL;
 763                 }
 764         }
 765 #else
 766         if ('r' != applet0)
 767                 argv[1] = NULL;
 768 #endif
 769
 770         if ('i' == applet0) { /* insmod */
 771                 size_t len;
 772                 void *map;
 773
 774                 len = MAXINT(ssize_t);
 775                 map = xmalloc_xopen_read_close(*argv, &len);
 776                 if (init_module(map, len,
 777                         USE_FEATURE_MODPROBE_SMALL_OPTIONS_ON_CMDLINE(options ? options : "")
 778                         SKIP_FEATURE_MODPROBE_SMALL_OPTIONS_ON_CMDLINE("")
 779                                 ) != 0)
 780                         bb_error_msg_and_die("can't insert '%s': %s",
 781                                         *argv, moderror(errno));
 782                 return 0;
 783         }
 784
 785         /* Try to load modprobe.dep.bb */
 786         load_dep_bb();
 787
 788         /* Load/remove modules.
 789          * Only rmmod loops here, modprobe has only argv[0] */
 790         do {
 791                 process_module(*argv++, options);
 792         } while (*argv);
 793
 794         if (ENABLE_FEATURE_CLEAN_UP) {
 795                 USE_FEATURE_MODPROBE_SMALL_OPTIONS_ON_CMDLINE(free(options);)
 796         }
 797         return EXIT_SUCCESS;
 798 }