libkmod/libkmod-module.c

   1 /*
   2  * libkmod - interface to kernel module operations
   3  *
   4  * Copyright (C) 2011  ProFUSION embedded systems
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  */
  20
  21 #include <assert.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <stddef.h>
  25 #include <stdarg.h>
  26 #include <unistd.h>
  27 #include <errno.h>
  28 #include <string.h>
  29 #include <ctype.h>
  30 #include <inttypes.h>
  31 #include <limits.h>
  32 #include <dirent.h>
  33 #include <sys/stat.h>
  34 #include <sys/types.h>
  35 #include <sys/mman.h>
  36 #include <string.h>
  37
  38 #include "libkmod.h"
  39 #include "libkmod-private.h"
  40
  41 /**
  42  * kmod_module:
  43  *
  44  * Opaque object representing a module.
  45  */
  46 struct kmod_module {
  47         struct kmod_ctx *ctx;
  48         char *hashkey;
  49         char *name;
  50         char *path;
  51         struct kmod_list *dep;
  52         char *options;
  53         char *install_commands;
  54         char *remove_commands;
  55         char *alias; /* only set if this module was created from an alias */
  56         int n_dep;
  57         int refcount;
  58         struct {
  59                 bool dep : 1;
  60                 bool options : 1;
  61                 bool install_commands : 1;
  62                 bool remove_commands : 1;
  63         } init;
  64 };
  65
  66 inline char *modname_normalize(const char *modname, char buf[NAME_MAX],
  67                                                                 size_t *len)
  68 {
  69         size_t s;
  70
  71         for (s = 0; s < NAME_MAX - 1; s++) {
  72                 const char c = modname[s];
  73                 if (c == '-')
  74                         buf[s] = '_';
  75                 else if (c == '\0' || c == '.')
  76                         break;
  77                 else
  78                         buf[s] = c;
  79         }
  80
  81         buf[s] = '\0';
  82
  83         if (len)
  84                 *len = s;
  85
  86         return buf;
  87 }
  88
  89 static char *path_to_modname(const char *path, char buf[NAME_MAX], size_t *len)
  90 {
  91         char *modname;
  92
  93         modname = basename(path);
  94         if (modname == NULL || modname[0] == '\0')
  95                 return NULL;
  96
  97         return modname_normalize(modname, buf, len);
  98 }
  99
 100 static inline const char *path_join(const char *path, size_t prefixlen,
 101                                                         char buf[PATH_MAX])
 102 {
 103         size_t pathlen;
 104
 105         if (path[0] == '/')
 106                 return path;
 107
 108         pathlen = strlen(path);
 109         if (prefixlen + pathlen + 1 >= PATH_MAX)
 110                 return NULL;
 111
 112         memcpy(buf + prefixlen, path, pathlen + 1);
 113         return buf;
 114 }
 115
 116 int kmod_module_parse_depline(struct kmod_module *mod, char *line)
 117 {
 118         struct kmod_ctx *ctx = mod->ctx;
 119         struct kmod_list *list = NULL;
 120         const char *dirname;
 121         char buf[PATH_MAX];
 122         char *p, *saveptr;
 123         int err = 0, n = 0;
 124         size_t dirnamelen;
 125
 126         if (mod->init.dep)
 127                 return mod->n_dep;
 128         assert(mod->dep == NULL);
 129         mod->init.dep = true;
 130
 131         p = strchr(line, ':');
 132         if (p == NULL)
 133                 return 0;
 134
 135         *p = '\0';
 136         dirname = kmod_get_dirname(mod->ctx);
 137         dirnamelen = strlen(dirname);
 138         if (dirnamelen + 2 >= PATH_MAX)
 139                 return 0;
 140
 141         memcpy(buf, dirname, dirnamelen);
 142         buf[dirnamelen] = '/';
 143         dirnamelen++;
 144         buf[dirnamelen] = '\0';
 145
 146         if (mod->path == NULL) {
 147                 const char *str = path_join(line, dirnamelen, buf);
 148                 if (str == NULL)
 149                         return 0;
 150                 mod->path = strdup(str);
 151                 if (mod->path == NULL)
 152                         return 0;
 153         }
 154
 155         p++;
 156         for (p = strtok_r(p, " \t", &saveptr); p != NULL;
 157                                         p = strtok_r(NULL, " \t", &saveptr)) {
 158                 struct kmod_module *depmod;
 159                 const char *path;
 160
 161                 path = path_join(p, dirnamelen, buf);
 162                 if (path == NULL) {
 163                         ERR(ctx, "could not join path '%s' and '%s'.\n",
 164                             dirname, p);
 165                         goto fail;
 166                 }
 167
 168                 err = kmod_module_new_from_path(ctx, path, &depmod);
 169                 if (err < 0) {
 170                         ERR(ctx, "ctx=%p path=%s error=%s\n",
 171                                                 ctx, path, strerror(-err));
 172                         goto fail;
 173                 }
 174
 175                 DBG(ctx, "add dep: %s\n", path);
 176
 177                 list = kmod_list_append(list, depmod);
 178                 n++;
 179         }
 180
 181         DBG(ctx, "%d dependencies for %s\n", n, mod->name);
 182
 183         mod->dep = list;
 184         mod->n_dep = n;
 185         return n;
 186
 187 fail:
 188         kmod_module_unref_list(list);
 189         mod->init.dep = false;
 190         return err;
 191 }
 192
 193 /**
 194  * kmod_module_new_from_name:
 195  * @ctx: kmod library context
 196  * @name: name of the module
 197  * @mod: where to save the created struct kmod_module
 198  *
 199  * Create a new struct kmod_module using the module name. @name can not be an
 200  * alias, file name or anything else; it must be a module name. There's no
 201  * check if the module does exists in the system.
 202  *
 203  * This function is also used internally by many others that return a new
 204  * struct kmod_module or a new list of modules.
 205  *
 206  * The initial refcount is 1, and needs to be decremented to release the
 207  * resources of the kmod_module. Since libkmod keeps track of all
 208  * kmod_modules created, they are all released upon @ctx destruction too. Do
 209  * not unref @ctx before all the desired operations with the returned
 210  * kmod_module are done.
 211  *
 212  * Returns: 0 on success or < 0 otherwise. It fails if name is not a valid
 213  * module name or if memory allocation failed.
 214  */
 215 KMOD_EXPORT int kmod_module_new_from_name(struct kmod_ctx *ctx,
 216                                                 const char *name,
 217                                                 struct kmod_module **mod)
 218 {
 219         struct kmod_module *m;
 220         size_t namelen;
 221         char name_norm[NAME_MAX];
 222         char *namesep;
 223
 224         if (ctx == NULL || name == NULL)
 225                 return -ENOENT;
 226
 227         alias_normalize(name, name_norm, &namelen);
 228
 229         m = kmod_pool_get_module(ctx, name_norm);
 230         if (m != NULL) {
 231                 *mod = kmod_module_ref(m);
 232                 return 0;
 233         }
 234
 235         namesep = strchr(name_norm, '/');
 236         m = malloc(sizeof(*m) + (namesep == NULL ? 1 : 2) * namelen + 2);
 237         if (m == NULL) {
 238                 free(m);
 239                 return -ENOMEM;
 240         }
 241
 242         memset(m, 0, sizeof(*m));
 243
 244         m->ctx = kmod_ref(ctx);
 245         m->name = (char *)m + sizeof(*m);
 246         memcpy(m->name, name_norm, namelen + 1);
 247
 248         if (namesep) {
 249                 size_t len = namesep - name_norm;
 250
 251                 m->name[len] = '\0';
 252                 m->alias = m->name + len + 1;
 253                 m->hashkey = m->name + namelen + 1;
 254                 memcpy(m->hashkey, name_norm, namelen + 1);
 255         } else {
 256                 m->hashkey = m->name;
 257         }
 258
 259         m->refcount = 1;
 260         kmod_pool_add_module(ctx, m, m->hashkey);
 261         *mod = m;
 262
 263         return 0;
 264 }
 265
 266 int kmod_module_new_from_alias(struct kmod_ctx *ctx, const char *alias,
 267                                 const char *name, struct kmod_module **mod)
 268 {
 269         int err;
 270         char key[NAME_MAX];
 271         size_t namelen = strlen(name);
 272         size_t aliaslen = strlen(alias);
 273
 274         if (namelen + aliaslen + 2 > NAME_MAX)
 275                 return -ENAMETOOLONG;
 276
 277         memcpy(key, name, namelen);
 278         memcpy(key + namelen + 1, alias, aliaslen + 1);
 279         key[namelen] = '/';
 280
 281         err = kmod_module_new_from_name(ctx, key, mod);
 282         if (err < 0)
 283                 return err;
 284
 285         return 0;
 286 }
 287
 288 /**
 289  * kmod_module_new_from_path:
 290  * @ctx: kmod library context
 291  * @path: path where to find the given module
 292  * @mod: where to save the created struct kmod_module
 293  *
 294  * Create a new struct kmod_module using the module path. @path must be an
 295  * existent file with in the filesystem and must be accessible to libkmod.
 296  *
 297  * The initial refcount is 1, and needs to be decremented to release the
 298  * resources of the kmod_module. Since libkmod keeps track of all
 299  * kmod_modules created, they are all released upon @ctx destruction too. Do
 300  * not unref @ctx before all the desired operations with the returned
 301  * kmod_module are done.
 302  *
 303  * If @path is relative, it's treated as relative to the current working
 304  * directory. Otherwise, give an absolute path.
 305  *
 306  * Returns: 0 on success or < 0 otherwise. It fails if file does not exist, if
 307  * it's not a valid file for a kmod_module or if memory allocation failed.
 308  */
 309 KMOD_EXPORT int kmod_module_new_from_path(struct kmod_ctx *ctx,
 310                                                 const char *path,
 311                                                 struct kmod_module **mod)
 312 {
 313         struct kmod_module *m;
 314         int err;
 315         struct stat st;
 316         char name[NAME_MAX];
 317         char *abspath;
 318         size_t namelen;
 319
 320         if (ctx == NULL || path == NULL)
 321                 return -ENOENT;
 322
 323         abspath = path_make_absolute_cwd(path);
 324         if (abspath == NULL)
 325                 return -ENOMEM;
 326
 327         err = stat(abspath, &st);
 328         if (err < 0) {
 329                 free(abspath);
 330                 return -errno;
 331         }
 332
 333         if (path_to_modname(path, name, &namelen) == NULL) {
 334                 free(abspath);
 335                 return -ENOENT;
 336         }
 337
 338         m = kmod_pool_get_module(ctx, name);
 339         if (m != NULL) {
 340                 if (m->path == NULL)
 341                         m->path = abspath;
 342                 else if (streq(m->path, abspath))
 343                         free(abspath);
 344                 else {
 345                         ERR(ctx, "kmod_module '%s' already exists with different path\n",
 346                                                                         name);
 347                         free(abspath);
 348                         return -EEXIST;
 349                 }
 350
 351                 *mod = kmod_module_ref(m);
 352                 return 0;
 353         }
 354
 355         m = malloc(sizeof(*m) + namelen + 1);
 356         if (m == NULL)
 357                 return -errno;
 358
 359         memset(m, 0, sizeof(*m));
 360
 361         m->ctx = kmod_ref(ctx);
 362         m->name = (char *)m + sizeof(*m);
 363         memcpy(m->name, name, namelen);
 364         m->path = abspath;
 365         m->hashkey = m->name;
 366         m->refcount = 1;
 367
 368         kmod_pool_add_module(ctx, m, m->hashkey);
 369
 370         *mod = m;
 371
 372         return 0;
 373 }
 374
 375 /**
 376  * kmod_module_unref:
 377  * @mod: kmod module
 378  *
 379  * Drop a reference of the kmod module. If the refcount reaches zero, its
 380  * resources are released.
 381  *
 382  * Returns: NULL if @mod is NULL or if the module was released. Otherwise it
 383  * returns the passed @mod with its refcount decremented.
 384  */
 385 KMOD_EXPORT struct kmod_module *kmod_module_unref(struct kmod_module *mod)
 386 {
 387         if (mod == NULL)
 388                 return NULL;
 389
 390         if (--mod->refcount > 0)
 391                 return mod;
 392
 393         DBG(mod->ctx, "kmod_module %p released\n", mod);
 394
 395         kmod_module_unref_list(mod->dep);
 396         kmod_unref(mod->ctx);
 397         free(mod->options);
 398         free(mod->install_commands);
 399         free(mod->remove_commands);
 400         free(mod->path);
 401         free(mod);
 402         return NULL;
 403 }
 404
 405 /**
 406  * kmod_module_ref:
 407  * @mod: kmod module
 408  *
 409  * Take a reference of the kmod module, incrementing its refcount.
 410  *
 411  * Returns: the passed @module with its refcount incremented.
 412  */
 413 KMOD_EXPORT struct kmod_module *kmod_module_ref(struct kmod_module *mod)
 414 {
 415         if (mod == NULL)
 416                 return NULL;
 417
 418         mod->refcount++;
 419
 420         return mod;
 421 }
 422
 423 #define CHECK_ERR_AND_FINISH(_err, _label_err, _list, label_finish)     \
 424         do {                                                            \
 425                 if ((_err) < 0)                                         \
 426                         goto _label_err;                                \
 427                 if (*(_list) != NULL)                                   \
 428                         goto finish;                                    \
 429         } while (0)
 430
 431 /**
 432  * kmod_module_new_from_lookup:
 433  * @ctx: kmod library context
 434  * @given_alias: alias to look for
 435  * @list: an empty list where to save the list of modules matching
 436  * @given_alias
 437  *
 438  * Create a new list of kmod modules using an alias or module name and lookup
 439  * libkmod's configuration files and indexes in order to find the module.
 440  * Once it's found in one of the places, it stops searching and create the
 441  * list of modules that is saved in @list.
 442  *
 443  * The search order is: 1. aliases in configuration file; 2. module names in
 444  * modules.dep index; 3. symbol aliases in modules.symbols index; 4. aliases
 445  * in modules.alias index.
 446  *
 447  * The initial refcount is 1, and needs to be decremented to release the
 448  * resources of the kmod_module. The returned @list must be released by
 449  * calling kmod_module_unref_list(). Since libkmod keeps track of all
 450  * kmod_modules created, they are all released upon @ctx destruction too. Do
 451  * not unref @ctx before all the desired operations with the returned list are
 452  * completed.
 453  *
 454  * Returns: 0 on success or < 0 otherwise. It fails if any of the lookup
 455  * methods failed, which is basically due to memory allocation fail. If module
 456  * is not found, it still returns 0, but @list is an empty list.
 457  */
 458 KMOD_EXPORT int kmod_module_new_from_lookup(struct kmod_ctx *ctx,
 459                                                 const char *given_alias,
 460                                                 struct kmod_list **list)
 461 {
 462         int err;
 463         char alias[NAME_MAX];
 464
 465         if (ctx == NULL || given_alias == NULL)
 466                 return -ENOENT;
 467
 468         if (list == NULL || *list != NULL) {
 469                 ERR(ctx, "An empty list is needed to create lookup\n");
 470                 return -ENOSYS;
 471         }
 472
 473         if (alias_normalize(given_alias, alias, NULL) < 0)
 474                 return -EINVAL;
 475
 476         /* Aliases from config file override all the others */
 477         err = kmod_lookup_alias_from_config(ctx, alias, list);
 478         CHECK_ERR_AND_FINISH(err, fail, list, finish);
 479
 480         err = kmod_lookup_alias_from_moddep_file(ctx, alias, list);
 481         CHECK_ERR_AND_FINISH(err, fail, list, finish);
 482
 483         err = kmod_lookup_alias_from_symbols_file(ctx, alias, list);
 484         CHECK_ERR_AND_FINISH(err, fail, list, finish);
 485
 486 // TODO: add lookup for install commands here.
 487
 488         err = kmod_lookup_alias_from_aliases_file(ctx, alias, list);
 489         CHECK_ERR_AND_FINISH(err, fail, list, finish);
 490
 491 finish:
 492
 493         return err;
 494 fail:
 495         kmod_module_unref_list(*list);
 496         *list = NULL;
 497         return err;
 498 }
 499 #undef CHECK_ERR_AND_FINISH
 500
 501 /**
 502  * kmod_module_unref_list:
 503  * @list: list of kmod modules
 504  *
 505  * Drop a reference of each kmod module in @list and releases the resources
 506  * taken by the list itself.
 507  *
 508  * Returns: NULL if @mod is NULL or if the module was released. Otherwise it
 509  * returns the passed @mod with its refcount decremented.
 510  */
 511 KMOD_EXPORT int kmod_module_unref_list(struct kmod_list *list)
 512 {
 513         for (; list != NULL; list = kmod_list_remove(list))
 514                 kmod_module_unref(list->data);
 515
 516         return 0;
 517 }
 518
 519 /**
 520  * kmod_module_get_dependencies:
 521  * @mod: kmod module
 522  *
 523  * Search the modules.dep index to find the dependencies of the given @mod.
 524  * The result is cached in @mod, so subsequent calls to this function will
 525  * return the already searched list of modules.
 526  *
 527  * Returns: NULL on failure or if there are any dependencies. Otherwise it
 528  * returns a list of kmod modules that can be released by calling
 529  * kmod_module_unref_list().
 530  */
 531 KMOD_EXPORT struct kmod_list *kmod_module_get_dependencies(const struct kmod_module *mod)
 532 {
 533         struct kmod_list *l, *l_new, *list_new = NULL;
 534
 535         if (mod == NULL)
 536                 return NULL;
 537
 538         if (!mod->init.dep) {
 539                 /* lazy init */
 540                 char *line = kmod_search_moddep(mod->ctx, mod->name);
 541
 542                 if (line == NULL)
 543                         return NULL;
 544
 545                 kmod_module_parse_depline((struct kmod_module *)mod, line);
 546                 free(line);
 547
 548                 if (!mod->init.dep)
 549                         return NULL;
 550         }
 551
 552         kmod_list_foreach(l, mod->dep) {
 553                 l_new = kmod_list_append(list_new, kmod_module_ref(l->data));
 554                 if (l_new == NULL) {
 555                         kmod_module_unref(l->data);
 556                         goto fail;
 557                 }
 558
 559                 list_new = l_new;
 560         }
 561
 562         return list_new;
 563
 564 fail:
 565         ERR(mod->ctx, "out of memory\n");
 566         kmod_module_unref_list(list_new);
 567         return NULL;
 568 }
 569
 570 /**
 571  * kmod_module_get_module:
 572  * @entry: an entry in a list of kmod modules.
 573  *
 574  * Get the kmod module of this @entry in the list, increasing its refcount.
 575  * After it's used, unref it. Since the refcount is incremented upon return,
 576  * you still have to call kmod_module_unref_list() to release the list of kmod
 577  * modules.
 578  *
 579  * Returns: NULL on failure or the kmod_module contained in this list entry
 580  * with its refcount incremented.
 581  */
 582 KMOD_EXPORT struct kmod_module *kmod_module_get_module(const struct kmod_list *entry)
 583 {
 584         if (entry == NULL)
 585                 return NULL;
 586
 587         return kmod_module_ref(entry->data);
 588 }
 589
 590 /**
 591  * kmod_module_get_name:
 592  * @mod: kmod module
 593  *
 594  * Get the name of this kmod module. Name is always available, independently
 595  * if it was created by kmod_module_new_from_name() or another function and
 596  * it's always normalized (dashes are replaced with underscores).
 597  *
 598  * Returns: the name of this kmod module.
 599  */
 600 KMOD_EXPORT const char *kmod_module_get_name(const struct kmod_module *mod)
 601 {
 602         return mod->name;
 603 }
 604
 605 /**
 606  * kmod_module_get_path:
 607  * @mod: kmod module
 608  *
 609  * Get the path of this kmod module. If this kmod module was not created by
 610  * path, it can search the modules.dep index in order to find out the module
 611  * under context's dirname (see kmod_get_dirname()).
 612  *
 613  * Returns: the path of this kmod module or NULL if such information is not
 614  * available.
 615  */
 616 KMOD_EXPORT const char *kmod_module_get_path(const struct kmod_module *mod)
 617 {
 618         char *line;
 619
 620         DBG(mod->ctx, "name='%s' path='%s'\n", mod->name, mod->path);
 621
 622         if (mod->path != NULL)
 623                 return mod->path;
 624         if (mod->init.dep)
 625                 return NULL;
 626
 627         /* lazy init */
 628         line = kmod_search_moddep(mod->ctx, mod->name);
 629         if (line == NULL)
 630                 return NULL;
 631
 632         kmod_module_parse_depline((struct kmod_module *) mod, line);
 633         free(line);
 634
 635         return mod->path;
 636 }
 637
 638
 639 extern long delete_module(const char *name, unsigned int flags);
 640
 641 /**
 642  * kmod_module_remove_module:
 643  * @mod: kmod module
 644  * @flags: flags to pass to Linux kernel when removing the module
 645  *
 646  * Remove a module from Linux kernel.
 647  *
 648  * Returns: 0 on success or < 0 on failure.
 649  */
 650 KMOD_EXPORT int kmod_module_remove_module(struct kmod_module *mod,
 651                                                         unsigned int flags)
 652 {
 653         int err;
 654
 655         if (mod == NULL)
 656                 return -ENOENT;
 657
 658         /* Filter out other flags */
 659         flags &= (KMOD_REMOVE_FORCE | KMOD_REMOVE_NOWAIT);
 660
 661         err = delete_module(mod->name, flags);
 662         if (err != 0) {
 663                 ERR(mod->ctx, "Could not remove '%s': %s\n", mod->name,
 664                                                         strerror(-err));
 665                 return err;
 666         }
 667
 668         return 0;
 669 }
 670
 671 extern long init_module(void *mem, unsigned long len, const char *args);
 672
 673 /**
 674  * kmod_module_insert_module:
 675  * @mod: kmod module
 676  * @flags: flags are not passed to Linux Kernel, but instead it dictates the
 677  * behavior of this function. They are not implemented yet.
 678  * @options: module's options to pass to Linux Kernel.
 679  *
 680  * Insert a module in Linux kernel. It opens the file pointed by @mod,
 681  * mmap'ing it and passing to kernel.
 682  *
 683  * Returns: 0 on success or < 0 on failure.
 684  */
 685 KMOD_EXPORT int kmod_module_insert_module(struct kmod_module *mod,
 686                                                         unsigned int flags,
 687                                                         const char *options)
 688 {
 689         int err;
 690         void *mmaped_file;
 691         struct stat st;
 692         int fd;
 693         const char *args = options ? options : "";
 694
 695         if (mod == NULL)
 696                 return -ENOENT;
 697
 698         if (mod->path == NULL) {
 699                 ERR(mod->ctx, "Not supported to load a module by name yet\n");
 700                 return -ENOSYS;
 701         }
 702
 703         if (flags != 0)
 704                 INFO(mod->ctx, "Flags are not implemented yet\n");
 705
 706         if ((fd = open(mod->path, O_RDONLY)) < 0) {
 707                 err = -errno;
 708                 return err;
 709         }
 710
 711         fstat(fd, &st);
 712
 713         if ((mmaped_file = mmap(0, st.st_size, PROT_READ,
 714                                         MAP_PRIVATE, fd, 0)) == MAP_FAILED) {
 715                 close(fd);
 716                 return -errno;
 717         }
 718
 719         err = init_module(mmaped_file, st.st_size, args);
 720         if (err < 0)
 721                 ERR(mod->ctx, "Failed to insert module '%s'\n", mod->path);
 722
 723         munmap(mmaped_file, st.st_size);
 724         close(fd);
 725
 726         return err;
 727 }
 728
 729 /**
 730  * kmod_module_get_options:
 731  * @mod: kmod module
 732  *
 733  * Get options of this kmod module. Options come from the configuration file
 734  * and are cached in @mod. The first call to this function will search for
 735  * this module in configuration and subsequent calls return the cached string.
 736  *
 737  * Returns: a string with all the options separated by spaces. This string is
 738  * owned by @mod, do not free it.
 739  */
 740 KMOD_EXPORT const char *kmod_module_get_options(const struct kmod_module *mod)
 741 {
 742         if (mod == NULL)
 743                 return NULL;
 744
 745         if (!mod->init.options) {
 746                 /* lazy init */
 747                 struct kmod_module *m = (struct kmod_module *)mod;
 748                 const struct kmod_list *l, *ctx_options;
 749                 char *opts = NULL;
 750                 size_t optslen = 0;
 751
 752                 ctx_options = kmod_get_options(mod->ctx);
 753
 754                 kmod_list_foreach(l, ctx_options) {
 755                         const char *modname = kmod_option_get_modname(l);
 756                         const char *str;
 757                         size_t len;
 758                         void *tmp;
 759
 760                         DBG(mod->ctx, "modname=%s mod->name=%s mod->alias=%s\n", modname, mod->name, mod->alias);
 761                         if (!(streq(modname, mod->name) || (mod->alias != NULL &&
 762                                                 streq(modname, mod->alias))))
 763                                 continue;
 764
 765                         DBG(mod->ctx, "passed = modname=%s mod->name=%s mod->alias=%s\n", modname, mod->name, mod->alias);
 766                         str = kmod_option_get_options(l);
 767                         len = strlen(str);
 768                         if (len < 1)
 769                                 continue;
 770
 771                         tmp = realloc(opts, optslen + len + 2);
 772                         if (tmp == NULL) {
 773                                 free(opts);
 774                                 goto failed;
 775                         }
 776
 777                         opts = tmp;
 778
 779                         if (optslen > 0) {
 780                                 opts[optslen] = ' ';
 781                                 optslen++;
 782                         }
 783
 784                         memcpy(opts + optslen, str, len);
 785                         optslen += len;
 786                         opts[optslen] = '\0';
 787                 }
 788
 789                 m->init.options = true;
 790                 m->options = opts;
 791         }
 792
 793         return mod->options;
 794
 795 failed:
 796         ERR(mod->ctx, "out of memory\n");
 797         return NULL;
 798 }
 799
 800 /**
 801  * kmod_module_get_install_commands:
 802  * @mod: kmod module
 803  *
 804  * Get install commands for this kmod module. Install commands come from the
 805  * configuration file and are cached in @mod. The first call to this function
 806  * will search for this module in configuration and subsequent calls return
 807  * the cached string. The install commands are returned as they were in the
 808  * configuration, concatenated by ';'. No other processing is made in this
 809  * string.
 810  *
 811  * Returns: a string with all install commands separated by semicolons. This
 812  * string is owned by @mod, do not free it.
 813  */
 814 KMOD_EXPORT const char *kmod_module_get_install_commands(const struct kmod_module *mod)
 815 {
 816         if (mod == NULL)
 817                 return NULL;
 818
 819         if (!mod->init.install_commands) {
 820                 /* lazy init */
 821                 struct kmod_module *m = (struct kmod_module *)mod;
 822                 const struct kmod_list *l, *ctx_install_commands;
 823                 char *cmds = NULL;
 824                 size_t cmdslen = 0;
 825
 826                 ctx_install_commands = kmod_get_install_commands(mod->ctx);
 827
 828                 kmod_list_foreach(l, ctx_install_commands) {
 829                         const char *modname = kmod_command_get_modname(l);
 830                         const char *str;
 831                         size_t len;
 832                         void *tmp;
 833
 834                         if (strcmp(modname, mod->name) != 0)
 835                                 continue;
 836
 837                         str = kmod_command_get_command(l);
 838                         len = strlen(str);
 839                         if (len < 1)
 840                                 continue;
 841
 842                         tmp = realloc(cmds, cmdslen + len + 2);
 843                         if (tmp == NULL) {
 844                                 free(cmds);
 845                                 goto failed;
 846                         }
 847
 848                         cmds = tmp;
 849
 850                         if (cmdslen > 0) {
 851                                 cmds[cmdslen] = ';';
 852                                 cmdslen++;
 853                         }
 854
 855                         memcpy(cmds + cmdslen, str, len);
 856                         cmdslen += len;
 857                         cmds[cmdslen] = '\0';
 858                 }
 859
 860                 m->init.install_commands = true;
 861                 m->install_commands = cmds;
 862         }
 863
 864         return mod->install_commands;
 865
 866 failed:
 867         ERR(mod->ctx, "out of memory\n");
 868         return NULL;
 869 }
 870
 871 /**
 872  * kmod_module_get_remove_commands:
 873  * @mod: kmod module
 874  *
 875  * Get remove commands for this kmod module. Remove commands come from the
 876  * configuration file and are cached in @mod. The first call to this function
 877  * will search for this module in configuration and subsequent calls return
 878  * the cached string. The remove commands are returned as they were in the
 879  * configuration, concatenated by ';'. No other processing is made in this
 880  * string.
 881  *
 882  * Returns: a string with all remove commands separated by semicolons. This
 883  * string is owned by @mod, do not free it.
 884  */
 885 KMOD_EXPORT const char *kmod_module_get_remove_commands(const struct kmod_module *mod)
 886 {
 887         if (mod == NULL)
 888                 return NULL;
 889
 890         if (!mod->init.remove_commands) {
 891                 /* lazy init */
 892                 struct kmod_module *m = (struct kmod_module *)mod;
 893                 const struct kmod_list *l, *ctx_remove_commands;
 894                 char *cmds = NULL;
 895                 size_t cmdslen = 0;
 896
 897                 ctx_remove_commands = kmod_get_remove_commands(mod->ctx);
 898
 899                 kmod_list_foreach(l, ctx_remove_commands) {
 900                         const char *modname = kmod_command_get_modname(l);
 901                         const char *str;
 902                         size_t len;
 903                         void *tmp;
 904
 905                         if (strcmp(modname, mod->name) != 0)
 906                                 continue;
 907
 908                         str = kmod_command_get_command(l);
 909                         len = strlen(str);
 910                         if (len < 1)
 911                                 continue;
 912
 913                         tmp = realloc(cmds, cmdslen + len + 2);
 914                         if (tmp == NULL) {
 915                                 free(cmds);
 916                                 goto failed;
 917                         }
 918
 919                         cmds = tmp;
 920
 921                         if (cmdslen > 0) {
 922                                 cmds[cmdslen] = ';';
 923                                 cmdslen++;
 924                         }
 925
 926                         memcpy(cmds + cmdslen, str, len);
 927                         cmdslen += len;
 928                         cmds[cmdslen] = '\0';
 929                 }
 930
 931                 m->init.remove_commands = true;
 932                 m->remove_commands = cmds;
 933         }
 934
 935         return mod->remove_commands;
 936
 937 failed:
 938         ERR(mod->ctx, "out of memory\n");
 939         return NULL;
 940 }
 941
 942 /**
 943  * SECTION:libkmod-loaded
 944  * @short_description: currently loaded modules
 945  *
 946  * Information about currently loaded modules, as reported by Linux kernel.
 947  * These information are not cached by libkmod and are always read from /sys
 948  * and /proc/modules.
 949  */
 950
 951 /**
 952  * kmod_module_new_from_loaded:
 953  * @ctx: kmod library context
 954  * @list: where to save the list of loaded modules
 955  *
 956  * Create a new list of kmod modules with all modules currently loaded in
 957  * kernel. It uses /proc/modules to get the names of loaded modules and to
 958  * create kmod modules by calling kmod_module_new_from_name() in each of them.
 959  * They are put are put in @list in no particular order.
 960  *
 961  * The initial refcount is 1, and needs to be decremented to release the
 962  * resources of the kmod_module. The returned @list must be released by
 963  * calling kmod_module_unref_list(). Since libkmod keeps track of all
 964  * kmod_modules created, they are all released upon @ctx destruction too. Do
 965  * not unref @ctx before all the desired operations with the returned list are
 966  * completed.
 967  *
 968  * Returns: 0 on success or < 0 on error.
 969  */
 970 KMOD_EXPORT int kmod_module_new_from_loaded(struct kmod_ctx *ctx,
 971                                                 struct kmod_list **list)
 972 {
 973         struct kmod_list *l = NULL;
 974         FILE *fp;
 975         char line[4096];
 976
 977         if (ctx == NULL || list == NULL)
 978                 return -ENOENT;
 979
 980         fp = fopen("/proc/modules", "r");
 981         if (fp == NULL) {
 982                 int err = -errno;
 983                 ERR(ctx, "could not open /proc/modules: %s\n", strerror(errno));
 984                 return err;
 985         }
 986
 987         while (fgets(line, sizeof(line), fp)) {
 988                 struct kmod_module *m;
 989                 struct kmod_list *node;
 990                 int err;
 991                 char *saveptr, *name = strtok_r(line, " \t", &saveptr);
 992
 993                 err = kmod_module_new_from_name(ctx, name, &m);
 994                 if (err < 0) {
 995                         ERR(ctx, "could not get module from name '%s': %s\n",
 996                                 name, strerror(-err));
 997                         continue;
 998                 }
 999
1000                 node = kmod_list_append(l, m);
1001                 if (node)
1002                         l = node;
1003                 else {
1004                         ERR(ctx, "out of memory\n");
1005                         kmod_module_unref(m);
1006                 }
1007         }
1008
1009         fclose(fp);
1010         *list = l;
1011
1012         return 0;
1013 }
1014
1015 /**
1016  * kmod_module_initstate_str:
1017  * @state: the state as returned by kmod_module_get_initstate()
1018  *
1019  * Translate a initstate to a string.
1020  *
1021  * Returns: the string associated to the @state. This string is statically
1022  * allocated, do not free it.
1023  */
1024 KMOD_EXPORT const char *kmod_module_initstate_str(enum kmod_module_initstate state)
1025 {
1026     switch (state) {
1027     case KMOD_MODULE_BUILTIN:
1028         return "builtin";
1029     case KMOD_MODULE_LIVE:
1030         return "live";
1031     case KMOD_MODULE_COMING:
1032         return "coming";
1033     case KMOD_MODULE_GOING:
1034         return "going";
1035     default:
1036         return NULL;
1037     }
1038 }
1039
1040 /**
1041  * kmod_module_get_initstate:
1042  * @mod: kmod module
1043  *
1044  * Get the initstate of this @mod, as returned by Linux Kernel, by reading
1045  * /sys filesystem.
1046  *
1047  * Returns: < 0 on error or enum kmod_initstate if module is found in kernel.
1048  */
1049 KMOD_EXPORT int kmod_module_get_initstate(const struct kmod_module *mod)
1050 {
1051         char path[PATH_MAX], buf[32];
1052         int fd, err, pathlen;
1053
1054         pathlen = snprintf(path, sizeof(path),
1055                                 "/sys/module/%s/initstate", mod->name);
1056         fd = open(path, O_RDONLY);
1057         if (fd < 0) {
1058                 err = -errno;
1059
1060                 if (pathlen > (int)sizeof("/initstate") - 1) {
1061                         struct stat st;
1062                         path[pathlen - (sizeof("/initstate") - 1)] = '\0';
1063                         if (stat(path, &st) == 0 && S_ISDIR(st.st_mode))
1064                                 return KMOD_MODULE_BUILTIN;
1065                 }
1066
1067                 DBG(mod->ctx, "could not open '%s': %s\n",
1068                         path, strerror(-err));
1069                 return err;
1070         }
1071
1072         err = read_str_safe(fd, buf, sizeof(buf));
1073         close(fd);
1074         if (err < 0) {
1075                 ERR(mod->ctx, "could not read from '%s': %s\n",
1076                         path, strerror(-err));
1077                 return err;
1078         }
1079
1080         if (streq(buf, "live\n"))
1081                 return KMOD_MODULE_LIVE;
1082         else if (streq(buf, "coming\n"))
1083                 return KMOD_MODULE_COMING;
1084         else if (streq(buf, "going\n"))
1085                 return KMOD_MODULE_GOING;
1086
1087         ERR(mod->ctx, "unknown %s: '%s'\n", path, buf);
1088         return -EINVAL;
1089 }
1090
1091 /**
1092  * kmod_module_get_size:
1093  * @mod: kmod module
1094  *
1095  * Get the size of this kmod module as returned by Linux kernel. It reads the
1096  * file /proc/modules to search for this module and get its size.
1097  *
1098  * Returns: the size of this kmod module.
1099  */
1100 KMOD_EXPORT long kmod_module_get_size(const struct kmod_module *mod)
1101 {
1102         // FIXME TODO: this should be available from /sys/module/foo
1103         FILE *fp;
1104         char line[4096];
1105         int lineno = 0;
1106         long size = -ENOENT;
1107
1108         if (mod == NULL)
1109                 return -ENOENT;
1110
1111         fp = fopen("/proc/modules", "r");
1112         if (fp == NULL) {
1113                 int err = -errno;
1114                 ERR(mod->ctx,
1115                     "could not open /proc/modules: %s\n", strerror(errno));
1116                 return err;
1117         }
1118
1119         while (fgets(line, sizeof(line), fp)) {
1120                 char *saveptr, *endptr, *tok = strtok_r(line, " \t", &saveptr);
1121                 long value;
1122
1123                 lineno++;
1124                 if (tok == NULL || !streq(tok, mod->name))
1125                         continue;
1126
1127                 tok = strtok_r(NULL, " \t", &saveptr);
1128                 if (tok == NULL) {
1129                         ERR(mod->ctx,
1130                         "invalid line format at /proc/modules:%d\n", lineno);
1131                         break;
1132                 }
1133
1134                 value = strtol(tok, &endptr, 10);
1135                 if (endptr == tok || *endptr != '\0') {
1136                         ERR(mod->ctx,
1137                         "invalid line format at /proc/modules:%d\n", lineno);
1138                         break;
1139                 }
1140
1141                 size = value;
1142                 break;
1143         }
1144         fclose(fp);
1145         return size;
1146 }
1147
1148 /**
1149  * kmod_module_get_refcnt:
1150  * @mod: kmod module
1151  *
1152  * Get the ref count of this @mod, as returned by Linux Kernel, by reading
1153  * /sys filesystem.
1154  *
1155  * Returns: 0 on success or < 0 on failure.
1156  */
1157 KMOD_EXPORT int kmod_module_get_refcnt(const struct kmod_module *mod)
1158 {
1159         char path[PATH_MAX];
1160         long refcnt;
1161         int fd, err;
1162
1163         snprintf(path, sizeof(path), "/sys/module/%s/refcnt", mod->name);
1164         fd = open(path, O_RDONLY);
1165         if (fd < 0) {
1166                 err = -errno;
1167                 ERR(mod->ctx, "could not open '%s': %s\n",
1168                         path, strerror(errno));
1169                 return err;
1170         }
1171
1172         err = read_str_long(fd, &refcnt, 10);
1173         close(fd);
1174         if (err < 0) {
1175                 ERR(mod->ctx, "could not read integer from '%s': '%s'\n",
1176                         path, strerror(-err));
1177                 return err;
1178         }
1179
1180         return (int)refcnt;
1181 }
1182
1183 /**
1184  * kmod_module_get_holders:
1185  * @mod: kmod module
1186  *
1187  * Get a list of kmod modules that are holding this @mod, as returned by Linux
1188  * Kernel. After use, free the @list by calling kmod_module_unref_list().
1189  *
1190  * Returns: a new list of kmod modules on success or NULL on failure.
1191  */
1192 KMOD_EXPORT struct kmod_list *kmod_module_get_holders(const struct kmod_module *mod)
1193 {
1194         char dname[PATH_MAX];
1195         struct kmod_list *list = NULL;
1196         DIR *d;
1197
1198         if (mod == NULL)
1199                 return NULL;
1200         snprintf(dname, sizeof(dname), "/sys/module/%s/holders", mod->name);
1201
1202         d = opendir(dname);
1203         if (d == NULL) {
1204                 ERR(mod->ctx, "could not open '%s': %s\n",
1205                                                 dname, strerror(errno));
1206                 return NULL;
1207         }
1208
1209         for (;;) {
1210                 struct dirent de, *entp;
1211                 struct kmod_module *holder;
1212                 struct kmod_list *l;
1213                 int err;
1214
1215                 err = readdir_r(d, &de, &entp);
1216                 if (err != 0) {
1217                         ERR(mod->ctx, "could not iterate for module '%s': %s\n",
1218                                                 mod->name, strerror(-err));
1219                         goto fail;
1220                 }
1221
1222                 if (entp == NULL)
1223                         break;
1224
1225                 if (de.d_name[0] == '.') {
1226                         if (de.d_name[1] == '\0' ||
1227                             (de.d_name[1] == '.' && de.d_name[2] == '\0'))
1228                                 continue;
1229                 }
1230
1231                 err = kmod_module_new_from_name(mod->ctx, de.d_name, &holder);
1232                 if (err < 0) {
1233                         ERR(mod->ctx, "could not create module for '%s': %s\n",
1234                                 de.d_name, strerror(-err));
1235                         goto fail;
1236                 }
1237
1238                 l = kmod_list_append(list, holder);
1239                 if (l != NULL) {
1240                         list = l;
1241                 } else {
1242                         ERR(mod->ctx, "out of memory\n");
1243                         kmod_module_unref(holder);
1244                         goto fail;
1245                 }
1246         }
1247
1248         closedir(d);
1249         return list;
1250
1251 fail:
1252         closedir(d);
1253         kmod_module_unref_list(list);
1254         return NULL;
1255 }
1256
1257 struct kmod_module_section {
1258         unsigned long address;
1259         char name[];
1260 };
1261
1262 static void kmod_module_section_free(struct kmod_module_section *section)
1263 {
1264         free(section);
1265 }
1266
1267 /**
1268  * kmod_module_get_sections:
1269  * @mod: kmod module
1270  *
1271  * Get a list of kmod sections of this @mod, as returned by Linux Kernel. The
1272  * structure contained in this list is internal to libkmod and their fields
1273  * can be obtained by calling kmod_module_section_get_name() and
1274  * kmod_module_section_get_address().
1275  *
1276  * After use, free the @list by calling kmod_module_section_free_list().
1277  *
1278  * Returns: a new list of kmod module sections on success or NULL on failure.
1279  */
1280 KMOD_EXPORT struct kmod_list *kmod_module_get_sections(const struct kmod_module *mod)
1281 {
1282         char dname[PATH_MAX];
1283         struct kmod_list *list = NULL;
1284         DIR *d;
1285         int dfd;
1286
1287         if (mod == NULL)
1288                 return NULL;
1289
1290         snprintf(dname, sizeof(dname), "/sys/module/%s/sections", mod->name);
1291
1292         d = opendir(dname);
1293         if (d == NULL) {
1294                 ERR(mod->ctx, "could not open '%s': %s\n",
1295                         dname, strerror(errno));
1296                 return NULL;
1297         }
1298
1299         dfd = dirfd(d);
1300
1301         for (;;) {
1302                 struct dirent de, *entp;
1303                 struct kmod_module_section *section;
1304                 struct kmod_list *l;
1305                 unsigned long address;
1306                 size_t namesz;
1307                 int fd, err;
1308
1309                 err = readdir_r(d, &de, &entp);
1310                 if (err != 0) {
1311                         ERR(mod->ctx, "could not iterate for module '%s': %s\n",
1312                                                 mod->name, strerror(-err));
1313                         goto fail;
1314                 }
1315
1316                 if (de.d_name[0] == '.') {
1317                         if (de.d_name[1] == '\0' ||
1318                             (de.d_name[1] == '.' && de.d_name[2] == '\0'))
1319                                 continue;
1320                 }
1321
1322                 fd = openat(dfd, de.d_name, O_RDONLY);
1323                 if (fd < 0) {
1324                         ERR(mod->ctx, "could not open '%s/%s': %m\n",
1325                                                         dname, de.d_name);
1326                         goto fail;
1327                 }
1328
1329                 err = read_str_ulong(fd, &address, 16);
1330                 close(fd);
1331                 if (err < 0) {
1332                         ERR(mod->ctx, "could not read long from '%s/%s': %m\n",
1333                                                         dname, de.d_name);
1334                         goto fail;
1335                 }
1336
1337                 namesz = strlen(de.d_name) + 1;
1338                 section = malloc(sizeof(*section) + namesz);
1339
1340                 if (section == NULL) {
1341                         ERR(mod->ctx, "out of memory\n");
1342                         goto fail;
1343                 }
1344
1345                 section->address = address;
1346                 memcpy(section->name, de.d_name, namesz);
1347
1348                 l = kmod_list_append(list, section);
1349                 if (l != NULL) {
1350                         list = l;
1351                 } else {
1352                         ERR(mod->ctx, "out of memory\n");
1353                         free(section);
1354                         goto fail;
1355                 }
1356         }
1357
1358         closedir(d);
1359         return list;
1360
1361 fail:
1362         closedir(d);
1363         kmod_module_unref_list(list);
1364         return NULL;
1365 }
1366
1367 /**
1368  * kmod_module_section_get_module_name:
1369  * @entry: a list entry representing a kmod module section
1370  *
1371  * Get the name of a kmod module section.
1372  *
1373  * After use, free the @list by calling kmod_module_section_free_list().
1374  *
1375  * Returns: the name of this kmod module section on success or NULL on
1376  * failure. The string is owned by the section, do not free it.
1377  */
1378 KMOD_EXPORT const char *kmod_module_section_get_name(const struct kmod_list *entry)
1379 {
1380         struct kmod_module_section *section;
1381
1382         if (entry == NULL)
1383                 return NULL;
1384
1385         section = entry->data;
1386         return section->name;
1387 }
1388
1389 /**
1390  * kmod_module_section_get_address:
1391  * @entry: a list entry representing a kmod module section
1392  *
1393  * Get the address of a kmod module section.
1394  *
1395  * After use, free the @list by calling kmod_module_section_free_list().
1396  *
1397  * Returns: the address of this kmod module section on success or ULONG_MAX
1398  * on failure.
1399  */
1400 KMOD_EXPORT unsigned long kmod_module_section_get_address(const struct kmod_list *entry)
1401 {
1402         struct kmod_module_section *section;
1403
1404         if (entry == NULL)
1405                 return (unsigned long)-1;
1406
1407         section = entry->data;
1408         return section->address;
1409 }
1410
1411 /**
1412  * kmod_module_section_free_list:
1413  * @list: kmod module section list
1414  *
1415  * Release the resources taken by @list
1416  */
1417 KMOD_EXPORT void kmod_module_section_free_list(struct kmod_list *list)
1418 {
1419         while (list) {
1420                 kmod_module_section_free(list->data);
1421                 list = kmod_list_remove(list);
1422         }
1423 }