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 /* Note that unlike older versions of modules.dep/depmod (busybox and m-i-t),
  12  * we expect the full dependency list to be specified in modules.dep.  Older
  13  * versions would only export the direct dependency list.
  14  */
  15
  16 #include "libbb.h"
  17 #include "modutils.h"
  18 #include <sys/utsname.h>
  19 #include <fnmatch.h>
  20
  21 //#define DBG(fmt, ...) bb_error_msg("%s: " fmt, __func__, ## __VA_ARGS__)
  22 #define DBG(...) ((void)0)
  23
  24 #define MODULE_FLAG_LOADED              0x0001
  25 #define MODULE_FLAG_NEED_DEPS           0x0002
  26 /* "was seen in modules.dep": */
  27 #define MODULE_FLAG_FOUND_IN_MODDEP     0x0004
  28 #define MODULE_FLAG_BLACKLISTED         0x0008
  29
  30 struct module_entry { /* I'll call it ME. */
  31         unsigned flags;
  32         char *modname; /* stripped of /path/, .ext and s/-/_/g */
  33         const char *probed_name; /* verbatim as seen on cmdline */
  34         char *options; /* options from config files */
  35         llist_t *realnames; /* strings. if this module is an alias, */
  36         /* real module name is one of these. */
  37 //Can there really be more than one? Example from real kernel?
  38         llist_t *deps; /* strings. modules we depend on */
  39 };
  40
  41 #define MODPROBE_OPTS  "acdlnrt:VC:" USE_FEATURE_MODPROBE_BLACKLIST("b")
  42 enum {
  43         MODPROBE_OPT_INSERT_ALL = (INSMOD_OPT_UNUSED << 0), /* a */
  44         MODPROBE_OPT_DUMP_ONLY  = (INSMOD_OPT_UNUSED << 1), /* c */
  45         MODPROBE_OPT_D          = (INSMOD_OPT_UNUSED << 2), /* d */
  46         MODPROBE_OPT_LIST_ONLY  = (INSMOD_OPT_UNUSED << 3), /* l */
  47         MODPROBE_OPT_SHOW_ONLY  = (INSMOD_OPT_UNUSED << 4), /* n */
  48         MODPROBE_OPT_REMOVE     = (INSMOD_OPT_UNUSED << 5), /* r */
  49         MODPROBE_OPT_RESTRICT   = (INSMOD_OPT_UNUSED << 6), /* t */
  50         MODPROBE_OPT_VERONLY    = (INSMOD_OPT_UNUSED << 7), /* V */
  51         MODPROBE_OPT_CONFIGFILE = (INSMOD_OPT_UNUSED << 8), /* C */
  52         MODPROBE_OPT_BLACKLIST  = (INSMOD_OPT_UNUSED << 9) * ENABLE_FEATURE_MODPROBE_BLACKLIST,
  53 };
  54
  55 struct globals {
  56         llist_t *db; /* MEs of all modules ever seen (caching for speed) */
  57         llist_t *probes; /* MEs of module(s) requested on cmdline */
  58         char *cmdline_mopts; /* module options from cmdline */
  59         int num_unresolved_deps;
  60         /* bool. "Did we have 'symbol:FOO' requested on cmdline?" */
  61         smallint need_symbols;
  62 };
  63 #define G (*(struct globals*)&bb_common_bufsiz1)
  64 #define INIT_G() do { } while (0)
  65
  66
  67 static int read_config(const char *path);
  68
  69 static char *gather_options_str(char *opts, const char *append)
  70 {
  71         /* Speed-optimized. We call gather_options_str many times. */
  72         if (opts == NULL) {
  73                 opts = xstrdup(append);
  74         } else {
  75                 int optlen = strlen(opts);
  76                 opts = xrealloc(opts, optlen + strlen(append) + 2);
  77                 sprintf(opts + optlen, " %s", append);
  78         }
  79         return opts;
  80 }
  81
  82 static struct module_entry *helper_get_module(const char *module, int create)
  83 {
  84         char modname[MODULE_NAME_LEN];
  85         struct module_entry *e;
  86         llist_t *l;
  87
  88         filename2modname(module, modname);
  89         for (l = G.db; l != NULL; l = l->link) {
  90                 e = (struct module_entry *) l->data;
  91                 if (strcmp(e->modname, modname) == 0)
  92                         return e;
  93         }
  94         if (!create)
  95                 return NULL;
  96
  97         e = xzalloc(sizeof(*e));
  98         e->modname = xstrdup(modname);
  99         llist_add_to(&G.db, e);
 100
 101         return e;
 102 }
 103 static struct module_entry *get_or_add_modentry(const char *module)
 104 {
 105         return helper_get_module(module, 1);
 106 }
 107 static struct module_entry *get_modentry(const char *module)
 108 {
 109         return helper_get_module(module, 0);
 110 }
 111
 112 static void add_probe(const char *name)
 113 {
 114         struct module_entry *m;
 115
 116         m = get_or_add_modentry(name);
 117         if (!(option_mask32 & MODPROBE_OPT_REMOVE)
 118          && (m->flags & MODULE_FLAG_LOADED)
 119         ) {
 120                 DBG("skipping %s, it is already loaded", name);
 121                 return;
 122         }
 123
 124         DBG("queuing %s", name);
 125         m->probed_name = name;
 126         m->flags |= MODULE_FLAG_NEED_DEPS;
 127         llist_add_to_end(&G.probes, m);
 128         G.num_unresolved_deps++;
 129         if (ENABLE_FEATURE_MODUTILS_SYMBOLS
 130          && strncmp(m->modname, "symbol:", 7) == 0
 131         ) {
 132                 G.need_symbols = 1;
 133         }
 134 }
 135
 136 static int FAST_FUNC config_file_action(const char *filename,
 137                                         struct stat *statbuf UNUSED_PARAM,
 138                                         void *userdata UNUSED_PARAM,
 139                                         int depth UNUSED_PARAM)
 140 {
 141         char *tokens[3];
 142         parser_t *p;
 143         struct module_entry *m;
 144         int rc = TRUE;
 145
 146         if (bb_basename(filename)[0] == '.')
 147                 goto error;
 148
 149         p = config_open2(filename, fopen_for_read);
 150         if (p == NULL) {
 151                 rc = FALSE;
 152                 goto error;
 153         }
 154
 155         while (config_read(p, tokens, 3, 2, "# \t", PARSE_NORMAL)) {
 156 //Use index_in_strings?
 157                 if (strcmp(tokens[0], "alias") == 0) {
 158                         /* alias <wildcard> <modulename> */
 159                         llist_t *l;
 160                         char wildcard[MODULE_NAME_LEN];
 161                         char *rmod;
 162
 163                         if (tokens[2] == NULL)
 164                                 continue;
 165                         filename2modname(tokens[1], wildcard);
 166
 167                         for (l = G.probes; l != NULL; l = l->link) {
 168                                 m = (struct module_entry *) l->data;
 169                                 if (fnmatch(wildcard, m->modname, 0) != 0)
 170                                         continue;
 171                                 rmod = filename2modname(tokens[2], NULL);
 172                                 llist_add_to(&m->realnames, rmod);
 173
 174                                 if (m->flags & MODULE_FLAG_NEED_DEPS) {
 175                                         m->flags &= ~MODULE_FLAG_NEED_DEPS;
 176                                         G.num_unresolved_deps--;
 177                                 }
 178
 179                                 m = get_or_add_modentry(rmod);
 180                                 if (!(m->flags & MODULE_FLAG_NEED_DEPS)) {
 181                                         m->flags |= MODULE_FLAG_NEED_DEPS;
 182                                         G.num_unresolved_deps++;
 183                                 }
 184                         }
 185                 } else if (strcmp(tokens[0], "options") == 0) {
 186                         /* options <modulename> <option...> */
 187                         if (tokens[2] == NULL)
 188                                 continue;
 189                         m = get_or_add_modentry(tokens[1]);
 190                         m->options = gather_options_str(m->options, tokens[2]);
 191                 } else if (strcmp(tokens[0], "include") == 0) {
 192                         /* include <filename> */
 193                         read_config(tokens[1]);
 194                 } else if (ENABLE_FEATURE_MODPROBE_BLACKLIST
 195                  && strcmp(tokens[0], "blacklist") == 0
 196                 ) {
 197                         /* blacklist <modulename> */
 198                         get_or_add_modentry(tokens[1])->flags |= MODULE_FLAG_BLACKLISTED;
 199                 }
 200         }
 201         config_close(p);
 202 error:
 203         return rc;
 204 }
 205
 206 static int read_config(const char *path)
 207 {
 208         return recursive_action(path, ACTION_RECURSE | ACTION_QUIET,
 209                                 config_file_action, NULL, NULL, 1);
 210 }
 211
 212 static int do_modprobe(struct module_entry *m)
 213 {
 214         struct module_entry *m2 = m2; /* for compiler */
 215         char *fn, *options;
 216         int rc, first;
 217         llist_t *l;
 218
 219         if (!(m->flags & MODULE_FLAG_FOUND_IN_MODDEP)) {
 220                 DBG("skipping %s, not found in modules.dep", m->modname);
 221                 return -ENOENT;
 222         }
 223         DBG("do_modprob'ing %s", m->modname);
 224
 225         if (!(option_mask32 & MODPROBE_OPT_REMOVE))
 226                 m->deps = llist_rev(m->deps);
 227
 228         for (l = m->deps; l != NULL; l = l->link)
 229                 DBG("dep: %s", l->data);
 230
 231         first = 1;
 232         rc = 0;
 233         while (m->deps && rc == 0) {
 234                 fn = llist_pop(&m->deps);
 235                 m2 = get_or_add_modentry(fn);
 236                 if (option_mask32 & MODPROBE_OPT_REMOVE) {
 237                         if (m2->flags & MODULE_FLAG_LOADED) {
 238                                 if (bb_delete_module(m2->modname, O_EXCL) != 0) {
 239                                         if (first)
 240                                                 rc = errno;
 241                                 } else {
 242                                         m2->flags &= ~MODULE_FLAG_LOADED;
 243                                 }
 244                         }
 245                         /* do not error out if *deps* fail to unload */
 246                         first = 0;
 247                 } else if (!(m2->flags & MODULE_FLAG_LOADED)) {
 248                         options = m2->options;
 249                         m2->options = NULL;
 250                         if (m == m2)
 251                                 options = gather_options_str(options, G.cmdline_mopts);
 252                         rc = bb_init_module(fn, options);
 253                         DBG("loaded %s '%s', rc:%d", fn, options, rc);
 254                         if (rc == 0)
 255                                 m2->flags |= MODULE_FLAG_LOADED;
 256                         free(options);
 257                 } else {
 258                         DBG("%s is already loaded, skipping", fn);
 259                 }
 260
 261                 free(fn);
 262         }
 263
 264         if (rc && !(option_mask32 & INSMOD_OPT_SILENT)) {
 265                 bb_error_msg("failed to %sload module %s: %s",
 266                         (option_mask32 & MODPROBE_OPT_REMOVE) ? "un" : "",
 267                         m2->probed_name ? m2->probed_name : m2->modname,
 268                         moderror(rc)
 269                 );
 270         }
 271
 272         return rc;
 273 }
 274
 275 static void load_modules_dep(void)
 276 {
 277         struct module_entry *m;
 278         char *colon, *tokens[2];
 279         parser_t *p;
 280
 281         /* Modprobe does not work at all without modprobe.dep,
 282          * even if the full module name is given. Returning error here
 283          * was making us later confuse user with this message:
 284          * "module /full/path/to/existing/file/module.ko not found".
 285          * It's better to die immediately, with good message.
 286          * xfopen_for_read provides that. */
 287         p = config_open2(CONFIG_DEFAULT_DEPMOD_FILE, xfopen_for_read);
 288
 289         while (G.num_unresolved_deps
 290          && config_read(p, tokens, 2, 1, "# \t", PARSE_NORMAL)
 291         ) {
 292                 colon = last_char_is(tokens[0], ':');
 293                 if (colon == NULL)
 294                         continue;
 295                 *colon = 0;
 296
 297                 m = get_modentry(tokens[0]);
 298                 if (m == NULL)
 299                         continue;
 300
 301                 /* Optimization... */
 302                 if ((m->flags & MODULE_FLAG_LOADED)
 303                  && !(option_mask32 & MODPROBE_OPT_REMOVE)
 304                 ) {
 305                         DBG("skip deps of %s, it's already loaded", tokens[0]);
 306                         continue;
 307                 }
 308
 309                 m->flags |= MODULE_FLAG_FOUND_IN_MODDEP;
 310                 if ((m->flags & MODULE_FLAG_NEED_DEPS) && (m->deps == NULL)) {
 311                         G.num_unresolved_deps--;
 312                         llist_add_to(&m->deps, xstrdup(tokens[0]));
 313                         if (tokens[1])
 314                                 string_to_llist(tokens[1], &m->deps, " ");
 315                 } else
 316                         DBG("skipping dep line");
 317         }
 318         config_close(p);
 319 }
 320
 321 int modprobe_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 322 int modprobe_main(int argc UNUSED_PARAM, char **argv)
 323 {
 324         struct utsname uts;
 325         int rc;
 326         unsigned opt;
 327         struct module_entry *me;
 328
 329         opt_complementary = "q-v:v-q";
 330         opt = getopt32(argv, INSMOD_OPTS MODPROBE_OPTS INSMOD_ARGS, NULL, NULL);
 331         argv += optind;
 332
 333         if (opt & (MODPROBE_OPT_DUMP_ONLY | MODPROBE_OPT_LIST_ONLY |
 334                                 MODPROBE_OPT_SHOW_ONLY))
 335                 bb_error_msg_and_die("not supported");
 336
 337         if (!argv[0]) {
 338                 if (opt & MODPROBE_OPT_REMOVE) {
 339                         /* "modprobe -r" (w/o params).
 340                          * "If name is NULL, all unused modules marked
 341                          * autoclean will be removed".
 342                          */
 343                         if (bb_delete_module(NULL, O_NONBLOCK|O_EXCL) != 0)
 344                                 bb_perror_msg_and_die("rmmod");
 345                 }
 346                 return EXIT_SUCCESS;
 347         }
 348
 349         /* Goto modules location */
 350         xchdir(CONFIG_DEFAULT_MODULES_DIR);
 351         uname(&uts);
 352         xchdir(uts.release);
 353
 354         /* Retrieve module names of already loaded modules */
 355         {
 356                 char *s;
 357                 parser_t *parser = config_open2("/proc/modules", fopen_for_read);
 358                 while (config_read(parser, &s, 1, 1, "# \t", PARSE_NORMAL & ~PARSE_GREEDY))
 359                         get_or_add_modentry(s)->flags |= MODULE_FLAG_LOADED;
 360                 config_close(parser);
 361         }
 362
 363         if (opt & (MODPROBE_OPT_INSERT_ALL | MODPROBE_OPT_REMOVE)) {
 364                 /* Each argument is a module name */
 365                 do {
 366                         DBG("adding module %s", *argv);
 367                         add_probe(*argv++);
 368                 } while (*argv);
 369         } else {
 370                 /* First argument is module name, rest are parameters */
 371                 DBG("probing just module %s", *argv);
 372                 add_probe(argv[0]);
 373                 G.cmdline_mopts = parse_cmdline_module_options(argv);
 374         }
 375
 376         /* Happens if all requested modules are already loaded */
 377         if (G.probes == NULL)
 378                 return EXIT_SUCCESS;
 379
 380         read_config("/etc/modprobe.conf");
 381         read_config("/etc/modprobe.d");
 382         if (ENABLE_FEATURE_MODUTILS_SYMBOLS && G.need_symbols)
 383                 read_config("modules.symbols");
 384         load_modules_dep();
 385         if (ENABLE_FEATURE_MODUTILS_ALIAS && G.num_unresolved_deps) {
 386                 read_config("modules.alias");
 387                 load_modules_dep();
 388         }
 389
 390         while ((me = llist_pop(&G.probes)) != NULL) {
 391                 if (me->realnames == NULL) {
 392                         /* This is not an alias. Literal names are blacklisted
 393                          * only if '-b' is given.
 394                          */
 395                         if (!(opt & MODPROBE_OPT_BLACKLIST)
 396                          || !(me->flags & MODULE_FLAG_BLACKLISTED)
 397                         ) {
 398                                 rc = do_modprobe(me);
 399 //FIXME: what if rc > 0?
 400                                 if (rc < 0 && !(opt & INSMOD_OPT_SILENT))
 401                                         bb_error_msg("module %s not found",
 402                                                      me->probed_name);
 403                         }
 404                 } else {
 405                         /* Probe all realnames */
 406                         do {
 407                                 char *realname = llist_pop(&me->realnames);
 408                                 struct module_entry *m2;
 409
 410                                 DBG("probing %s by realname %s", me->modname, realname);
 411                                 m2 = get_or_add_modentry(realname);
 412                                 if (!(m2->flags & MODULE_FLAG_BLACKLISTED))
 413                                         do_modprobe(m2);
 414 //FIXME: error check?
 415                                 free(realname);
 416                         } while (me->realnames != NULL);
 417                 }
 418         }
 419
 420         return EXIT_SUCCESS;
 421 }