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

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Modprobe written from scratch for BusyBox
   4  *
   5  * Copyright (c) 2008 Timo Teras <timo.teras@iki.fi>
   6  * Copyright (c) 2008 Vladimir Dronnikov
   7  *
   8  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   9  */
  10
  11 #include "libbb.h"
  12 #include "modutils.h"
  13 #include <sys/utsname.h>
  14 #include <fnmatch.h>
  15
  16 //#define DBG(...) bb_error_msg(__VA_ARGS__)
  17 #define DBG(...) ((void)0)
  18
  19 #define MODULE_FLAG_LOADED              0x0001
  20 #define MODULE_FLAG_NEED_DEPS           0x0002
  21 /* "was seen in modules.dep": */
  22 #define MODULE_FLAG_FOUND_IN_MODDEP     0x0004
  23 #define MODULE_FLAG_BLACKLISTED         0x0008
  24
  25 struct module_entry { /* I'll call it ME. */
  26         unsigned flags;
  27         char *modname; /* stripped of /path/, .ext and s/-/_/g */
  28         const char *probed_name; /* verbatim as seen on cmdline */
  29         char *options; /* options from config files */
  30         llist_t *realnames; /* strings. if this module is an alias, */
  31         /* real module name is one of these. */
  32 //Can there really be more than one? Example from real kernel?
  33         llist_t *deps; /* strings. modules we depend on */
  34 };
  35
  36 #define MODPROBE_OPTS  "acdlnrt:VC:" USE_FEATURE_MODPROBE_BLACKLIST("b")
  37 enum {
  38         MODPROBE_OPT_INSERT_ALL = (INSMOD_OPT_UNUSED << 0), /* a */
  39         MODPROBE_OPT_DUMP_ONLY  = (INSMOD_OPT_UNUSED << 1), /* c */
  40         MODPROBE_OPT_D          = (INSMOD_OPT_UNUSED << 2), /* d */
  41         MODPROBE_OPT_LIST_ONLY  = (INSMOD_OPT_UNUSED << 3), /* l */
  42         MODPROBE_OPT_SHOW_ONLY  = (INSMOD_OPT_UNUSED << 4), /* n */
  43         MODPROBE_OPT_REMOVE     = (INSMOD_OPT_UNUSED << 5), /* r */
  44         MODPROBE_OPT_RESTRICT   = (INSMOD_OPT_UNUSED << 6), /* t */
  45         MODPROBE_OPT_VERONLY    = (INSMOD_OPT_UNUSED << 7), /* V */
  46         MODPROBE_OPT_CONFIGFILE = (INSMOD_OPT_UNUSED << 8), /* C */
  47         MODPROBE_OPT_BLACKLIST  = (INSMOD_OPT_UNUSED << 9) * ENABLE_FEATURE_MODPROBE_BLACKLIST,
  48 };
  49
  50 struct globals {
  51         llist_t *db; /* MEs of all modules ever seen (caching for speed) */
  52         llist_t *probes; /* MEs of module(s) requested on cmdline */
  53         char *cmdline_mopts; /* module options from cmdline */
  54         int num_unresolved_deps;
  55         /* bool. "Did we have 'symbol:FOO' requested on cmdline?" */
  56         smallint need_symbols;
  57 };
  58 #define G (*(struct globals*)&bb_common_bufsiz1)
  59 #define INIT_G() do { } while (0)
  60
  61
  62 static int read_config(const char *path);
  63
  64 static char *gather_options_str(char *opts, const char *append)
  65 {
  66         /* Speed-optimized. We call gather_options_str many times. */
  67         if (opts == NULL) {
  68                 opts = xstrdup(append);
  69         } else {
  70                 int optlen = strlen(opts);
  71                 opts = xrealloc(opts, optlen + strlen(append) + 2);
  72                 sprintf(opts + optlen, " %s", append);
  73         }
  74         return opts;
  75 }
  76
  77 static struct module_entry *helper_get_module(const char *module, int create)
  78 {
  79         char modname[MODULE_NAME_LEN];
  80         struct module_entry *e;
  81         llist_t *l;
  82
  83         filename2modname(module, modname);
  84         for (l = G.db; l != NULL; l = l->link) {
  85                 e = (struct module_entry *) l->data;
  86                 if (strcmp(e->modname, modname) == 0)
  87                         return e;
  88         }
  89         if (!create)
  90                 return NULL;
  91
  92         e = xzalloc(sizeof(*e));
  93         e->modname = xstrdup(modname);
  94         llist_add_to(&G.db, e);
  95
  96         return e;
  97 }
  98 static struct module_entry *get_or_add_modentry(const char *module)
  99 {
 100         return helper_get_module(module, 1);
 101 }
 102 static struct module_entry *get_modentry(const char *module)
 103 {
 104         return helper_get_module(module, 0);
 105 }
 106
 107 static void add_probe(const char *name)
 108 {
 109         struct module_entry *m;
 110
 111         m = get_or_add_modentry(name);
 112         if (m->flags & MODULE_FLAG_LOADED) {
 113                 DBG("skipping %s, it is already loaded", name);
 114                 return;
 115         }
 116
 117         m->probed_name = name;
 118         m->flags |= MODULE_FLAG_NEED_DEPS;
 119         llist_add_to_end(&G.probes, m);
 120         G.num_unresolved_deps++;
 121         if (ENABLE_FEATURE_MODUTILS_SYMBOLS
 122          && strncmp(m->modname, "symbol:", 7) == 0
 123         ) {
 124                 G.need_symbols = 1;
 125         }
 126 }
 127
 128 static int FAST_FUNC config_file_action(const char *filename,
 129                                         struct stat *statbuf UNUSED_PARAM,
 130                                         void *userdata UNUSED_PARAM,
 131                                         int depth UNUSED_PARAM)
 132 {
 133         char *tokens[3];
 134         parser_t *p;
 135         struct module_entry *m;
 136         int rc = TRUE;
 137
 138         if (bb_basename(filename)[0] == '.')
 139                 goto error;
 140
 141         p = config_open2(filename, fopen_for_read);
 142         if (p == NULL) {
 143                 rc = FALSE;
 144                 goto error;
 145         }
 146
 147         while (config_read(p, tokens, 3, 2, "# \t", PARSE_NORMAL)) {
 148 //Use index_in_strings?
 149                 if (strcmp(tokens[0], "alias") == 0) {
 150                         /* alias <wildcard> <modulename> */
 151                         llist_t *l;
 152                         char wildcard[MODULE_NAME_LEN];
 153                         char *rmod;
 154
 155                         if (tokens[2] == NULL)
 156                                 continue;
 157                         filename2modname(tokens[1], wildcard);
 158
 159                         for (l = G.probes; l != NULL; l = l->link) {
 160                                 m = (struct module_entry *) l->data;
 161                                 if (fnmatch(wildcard, m->modname, 0) != 0)
 162                                         continue;
 163                                 rmod = filename2modname(tokens[2], NULL);
 164                                 llist_add_to(&m->realnames, rmod);
 165
 166                                 if (m->flags & MODULE_FLAG_NEED_DEPS) {
 167                                         m->flags &= ~MODULE_FLAG_NEED_DEPS;
 168                                         G.num_unresolved_deps--;
 169                                 }
 170
 171                                 m = get_or_add_modentry(rmod);
 172                                 if (!(m->flags & MODULE_FLAG_NEED_DEPS)) {
 173                                         m->flags |= MODULE_FLAG_NEED_DEPS;
 174                                         G.num_unresolved_deps++;
 175                                 }
 176                         }
 177                 } else if (strcmp(tokens[0], "options") == 0) {
 178                         /* options <modulename> <option...> */
 179                         if (tokens[2] == NULL)
 180                                 continue;
 181                         m = get_or_add_modentry(tokens[1]);
 182                         m->options = gather_options_str(m->options, tokens[2]);
 183                 } else if (strcmp(tokens[0], "include") == 0) {
 184                         /* include <filename> */
 185                         read_config(tokens[1]);
 186                 } else if (ENABLE_FEATURE_MODPROBE_BLACKLIST
 187                  && strcmp(tokens[0], "blacklist") == 0
 188                 ) {
 189                         /* blacklist <modulename> */
 190                         get_or_add_modentry(tokens[1])->flags |= MODULE_FLAG_BLACKLISTED;
 191                 }
 192         }
 193         config_close(p);
 194 error:
 195         return rc;
 196 }
 197
 198 static int read_config(const char *path)
 199 {
 200         return recursive_action(path, ACTION_RECURSE | ACTION_QUIET,
 201                                 config_file_action, NULL, NULL, 1);
 202 }
 203
 204 static int do_modprobe(struct module_entry *m)
 205 {
 206         struct module_entry *m2;
 207         char *fn, *options;
 208         int rc = -1;
 209
 210         if (!(m->flags & MODULE_FLAG_FOUND_IN_MODDEP)) {
 211                 DBG("skipping %s, not found in modules.dep", m->modname);
 212                 return -ENOENT;
 213         }
 214         DBG("do_modprob'ing %s", m->modname);
 215
 216         if (!(option_mask32 & MODPROBE_OPT_REMOVE))
 217                 m->deps = llist_rev(m->deps);
 218
 219         rc = 0;
 220         while (m->deps && rc == 0) {
 221                 fn = llist_pop(&m->deps);
 222                 m2 = get_or_add_modentry(fn);
 223                 if (option_mask32 & MODPROBE_OPT_REMOVE) {
 224                         if (bb_delete_module(m->modname, O_EXCL) != 0)
 225                                 rc = errno;
 226                 } else if (!(m2->flags & MODULE_FLAG_LOADED)) {
 227                         options = m2->options;
 228                         m2->options = NULL;
 229                         if (m == m2)
 230                                 options = gather_options_str(options, G.cmdline_mopts);
 231                         rc = bb_init_module(fn, options);
 232                         DBG("loaded %s '%s', rc:%d", fn, options, rc);
 233                         if (rc == 0)
 234                                 m2->flags |= MODULE_FLAG_LOADED;
 235                         free(options);
 236                 } else {
 237                         DBG("%s is already loaded, skipping", fn);
 238                 }
 239
 240                 free(fn);
 241         }
 242
 243 //FIXME: what if rc < 0?
 244         if (rc > 0 && !(option_mask32 & INSMOD_OPT_SILENT)) {
 245                 bb_error_msg("failed to %sload module %s: %s",
 246                         (option_mask32 & MODPROBE_OPT_REMOVE) ? "un" : "",
 247                         m->probed_name ? m->probed_name : m->modname,
 248                         moderror(rc)
 249                 );
 250         }
 251
 252         return rc;
 253 }
 254
 255 static void load_modules_dep(void)
 256 {
 257         struct module_entry *m;
 258         char *colon, *tokens[2];
 259         parser_t *p;
 260
 261         /* Modprobe does not work at all without modprobe.dep,
 262          * even if the full module name is given. Returning error here
 263          * was making us later confuse user with this message:
 264          * "module /full/path/to/existing/file/module.ko not found".
 265          * It's better to die immediately, with good message.
 266          * xfopen_for_read provides that. */
 267         p = config_open2(CONFIG_DEFAULT_DEPMOD_FILE, xfopen_for_read);
 268
 269         while (G.num_unresolved_deps
 270          && config_read(p, tokens, 2, 1, "# \t", PARSE_NORMAL)
 271         ) {
 272                 colon = last_char_is(tokens[0], ':');
 273                 if (colon == NULL)
 274                         continue;
 275                 *colon = 0;
 276
 277                 m = get_modentry(tokens[0]);
 278                 if (m == NULL)
 279                         continue;
 280
 281                 /* Optimization... */
 282                 if ((m->flags & MODULE_FLAG_LOADED)
 283                  && !(option_mask32 & MODPROBE_OPT_REMOVE)
 284                 ) {
 285                         DBG("skip deps of %s, it's already loaded", tokens[0]);
 286                         continue;
 287                 }
 288
 289                 m->flags |= MODULE_FLAG_FOUND_IN_MODDEP;
 290                 if ((m->flags & MODULE_FLAG_NEED_DEPS) && (m->deps == NULL)) {
 291                         G.num_unresolved_deps--;
 292                         llist_add_to(&m->deps, xstrdup(tokens[0]));
 293                         if (tokens[1])
 294                                 string_to_llist(tokens[1], &m->deps, " ");
 295                 }
 296         }
 297         config_close(p);
 298 }
 299
 300 int modprobe_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 301 int modprobe_main(int argc UNUSED_PARAM, char **argv)
 302 {
 303         struct utsname uts;
 304         int rc;
 305         unsigned opt;
 306         struct module_entry *me;
 307
 308         opt_complementary = "q-v:v-q";
 309         opt = getopt32(argv, INSMOD_OPTS MODPROBE_OPTS INSMOD_ARGS, NULL, NULL);
 310         argv += optind;
 311
 312         if (opt & (MODPROBE_OPT_DUMP_ONLY | MODPROBE_OPT_LIST_ONLY |
 313                                 MODPROBE_OPT_SHOW_ONLY))
 314                 bb_error_msg_and_die("not supported");
 315
 316         if (!argv[0]) {
 317                 if (opt & MODPROBE_OPT_REMOVE) {
 318                         /* "modprobe -r" (w/o params).
 319                          * "If name is NULL, all unused modules marked
 320                          * autoclean will be removed".
 321                          */
 322                         if (bb_delete_module(NULL, O_NONBLOCK|O_EXCL) != 0)
 323                                 bb_perror_msg_and_die("rmmod");
 324                 }
 325                 return EXIT_SUCCESS;
 326         }
 327
 328         /* Goto modules location */
 329         xchdir(CONFIG_DEFAULT_MODULES_DIR);
 330         uname(&uts);
 331         xchdir(uts.release);
 332
 333         /* Retrieve module names of already loaded modules */
 334         {
 335                 char *s;
 336                 parser_t *parser = config_open2("/proc/modules", fopen_for_read);
 337                 while (config_read(parser, &s, 1, 1, "# \t", PARSE_NORMAL & ~PARSE_GREEDY))
 338                         get_or_add_modentry(s)->flags |= MODULE_FLAG_LOADED;
 339                 config_close(parser);
 340         }
 341
 342         if (opt & MODPROBE_OPT_INSERT_ALL) {
 343                 /* Each argument is a module name */
 344                 do {
 345                         add_probe(*argv++);
 346                 } while (*argv);
 347         } else {
 348                 /* First argument is module name, rest are parameters */
 349                 add_probe(argv[0]);
 350                 G.cmdline_mopts = parse_cmdline_module_options(argv);
 351         }
 352
 353         /* Happens if all requested modules are already loaded */
 354         if (G.probes == NULL)
 355                 return EXIT_SUCCESS;
 356
 357         read_config("/etc/modprobe.conf");
 358         read_config("/etc/modprobe.d");
 359         if (ENABLE_FEATURE_MODUTILS_SYMBOLS && G.need_symbols)
 360                 read_config("modules.symbols");
 361         load_modules_dep();
 362         if (ENABLE_FEATURE_MODUTILS_ALIAS && G.num_unresolved_deps) {
 363                 read_config("modules.alias");
 364                 load_modules_dep();
 365         }
 366
 367         while ((me = llist_pop(&G.probes)) != NULL) {
 368                 if (me->realnames == NULL) {
 369                         /* This is not an alias. Literal names are blacklisted
 370                          * only if '-b' is given.
 371                          */
 372                         if (!(opt & MODPROBE_OPT_BLACKLIST)
 373                          || !(me->flags & MODULE_FLAG_BLACKLISTED)
 374                         ) {
 375                                 rc = do_modprobe(me);
 376 //FIXME: what if rc > 0?
 377                                 if (rc < 0 && !(opt & INSMOD_OPT_SILENT))
 378                                         bb_error_msg("module %s not found",
 379                                                      me->probed_name);
 380                         }
 381                 } else {
 382                         /* Probe all realnames */
 383                         do {
 384                                 char *realname = llist_pop(&me->realnames);
 385                                 struct module_entry *m2;
 386
 387                                 DBG("probing %s by realname %s", me->modname, realname);
 388                                 m2 = get_or_add_modentry(realname);
 389                                 if (!(m2->flags & MODULE_FLAG_BLACKLISTED))
 390                                         do_modprobe(m2);
 391 //FIXME: error check?
 392                                 free(realname);
 393                         } while (me->realnames != NULL);
 394                 }
 395         }
 396
 397         return EXIT_SUCCESS;
 398 }