libkmod/libkmod.c

   1 /*
   2  * libkmod - interface to kernel module operations
   3  *
   4  * Copyright (C) 2011-2013  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, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <assert.h>
  21 #include <ctype.h>
  22 #include <errno.h>
  23 #include <fnmatch.h>
  24 #include <limits.h>
  25 #include <stdarg.h>
  26 #include <stddef.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <unistd.h>
  31 #include <sys/stat.h>
  32 #include <sys/utsname.h>
  33
  34 #include <shared/hash.h>
  35 #include <shared/util.h>
  36
  37 #include "libkmod.h"
  38 #include "libkmod-internal.h"
  39 #include "libkmod-index.h"
  40
  41 #define KMOD_HASH_SIZE (256)
  42 #define KMOD_LRU_MAX (128)
  43 #define _KMOD_INDEX_MODULES_SIZE KMOD_INDEX_MODULES_BUILTIN + 1
  44
  45 /**
  46  * SECTION:libkmod
  47  * @short_description: libkmod context
  48  *
  49  * The context contains the default values for the library user,
  50  * and is passed to all library operations.
  51  */
  52
  53 static struct _index_files {
  54         const char *fn;
  55         const char *prefix;
  56 } index_files[] = {
  57         [KMOD_INDEX_MODULES_DEP] = { .fn = "modules.dep", .prefix = "" },
  58         [KMOD_INDEX_MODULES_ALIAS] = { .fn = "modules.alias", .prefix = "alias " },
  59         [KMOD_INDEX_MODULES_SYMBOL] = { .fn = "modules.symbols", .prefix = "alias "},
  60         [KMOD_INDEX_MODULES_BUILTIN_ALIAS] = { .fn = "modules.builtin.alias", .prefix = "" },
  61         [KMOD_INDEX_MODULES_BUILTIN] = { .fn = "modules.builtin", .prefix = ""},
  62 };
  63
  64 static const char *default_config_paths[] = {
  65         SYSCONFDIR "/modprobe.d",
  66         "/run/modprobe.d",
  67         "/lib/modprobe.d",
  68         NULL
  69 };
  70
  71 /**
  72  * kmod_ctx:
  73  *
  74  * Opaque object representing the library context.
  75  */
  76 struct kmod_ctx {
  77         int refcount;
  78         int log_priority;
  79         void (*log_fn)(void *data,
  80                         int priority, const char *file, int line,
  81                         const char *fn, const char *format, va_list args);
  82         void *log_data;
  83         const void *userdata;
  84         char *dirname;
  85         struct kmod_config *config;
  86         struct hash *modules_by_name;
  87         struct index_mm *indexes[_KMOD_INDEX_MODULES_SIZE];
  88         unsigned long long indexes_stamp[_KMOD_INDEX_MODULES_SIZE];
  89 };
  90
  91 void kmod_log(const struct kmod_ctx *ctx,
  92                 int priority, const char *file, int line, const char *fn,
  93                 const char *format, ...)
  94 {
  95         va_list args;
  96
  97         if (ctx->log_fn == NULL)
  98                 return;
  99
 100         va_start(args, format);
 101         ctx->log_fn(ctx->log_data, priority, file, line, fn, format, args);
 102         va_end(args);
 103 }
 104
 105 _printf_format_(6, 0)
 106 static void log_filep(void *data,
 107                         int priority, const char *file, int line,
 108                         const char *fn, const char *format, va_list args)
 109 {
 110         FILE *fp = data;
 111 #ifdef ENABLE_DEBUG
 112         char buf[16];
 113         const char *priname;
 114         switch (priority) {
 115         case LOG_EMERG:
 116                 priname = "EMERGENCY";
 117                 break;
 118         case LOG_ALERT:
 119                 priname = "ALERT";
 120                 break;
 121         case LOG_CRIT:
 122                 priname = "CRITICAL";
 123                 break;
 124         case LOG_ERR:
 125                 priname = "ERROR";
 126                 break;
 127         case LOG_WARNING:
 128                 priname = "WARNING";
 129                 break;
 130         case LOG_NOTICE:
 131                 priname = "NOTICE";
 132                 break;
 133         case LOG_INFO:
 134                 priname = "INFO";
 135                 break;
 136         case LOG_DEBUG:
 137                 priname = "DEBUG";
 138                 break;
 139         default:
 140                 snprintf(buf, sizeof(buf), "L:%d", priority);
 141                 priname = buf;
 142         }
 143         fprintf(fp, "libkmod: %s %s:%d %s: ", priname, file, line, fn);
 144 #else
 145         fprintf(fp, "libkmod: %s: ", fn);
 146 #endif
 147         vfprintf(fp, format, args);
 148 }
 149
 150
 151 /**
 152  * kmod_get_dirname:
 153  * @ctx: kmod library context
 154  *
 155  * Retrieve the absolute path used for linux modules in this context. The path
 156  * is computed from the arguments to kmod_new().
 157  */
 158 KMOD_EXPORT const char *kmod_get_dirname(const struct kmod_ctx *ctx)
 159 {
 160         return ctx->dirname;
 161 }
 162
 163 /**
 164  * kmod_get_userdata:
 165  * @ctx: kmod library context
 166  *
 167  * Retrieve stored data pointer from library context. This might be useful
 168  * to access from callbacks.
 169  *
 170  * Returns: stored userdata
 171  */
 172 KMOD_EXPORT void *kmod_get_userdata(const struct kmod_ctx *ctx)
 173 {
 174         if (ctx == NULL)
 175                 return NULL;
 176         return (void *)ctx->userdata;
 177 }
 178
 179 /**
 180  * kmod_set_userdata:
 181  * @ctx: kmod library context
 182  * @userdata: data pointer
 183  *
 184  * Store custom @userdata in the library context.
 185  */
 186 KMOD_EXPORT void kmod_set_userdata(struct kmod_ctx *ctx, const void *userdata)
 187 {
 188         if (ctx == NULL)
 189                 return;
 190         ctx->userdata = userdata;
 191 }
 192
 193 static int log_priority(const char *priority)
 194 {
 195         char *endptr;
 196         int prio;
 197
 198         prio = strtol(priority, &endptr, 10);
 199         if (endptr[0] == '\0' || isspace(endptr[0]))
 200                 return prio;
 201         if (strncmp(priority, "err", 3) == 0)
 202                 return LOG_ERR;
 203         if (strncmp(priority, "info", 4) == 0)
 204                 return LOG_INFO;
 205         if (strncmp(priority, "debug", 5) == 0)
 206                 return LOG_DEBUG;
 207         return 0;
 208 }
 209
 210 static const char *dirname_default_prefix = "/lib/modules";
 211
 212 static char *get_kernel_release(const char *dirname)
 213 {
 214         struct utsname u;
 215         char *p;
 216
 217         if (dirname != NULL)
 218                 return path_make_absolute_cwd(dirname);
 219
 220         if (uname(&u) < 0)
 221                 return NULL;
 222
 223         if (asprintf(&p, "%s/%s", dirname_default_prefix, u.release) < 0)
 224                 return NULL;
 225
 226         return p;
 227 }
 228
 229 /**
 230  * kmod_new:
 231  * @dirname: what to consider as linux module's directory, if NULL
 232  *           defaults to /lib/modules/`uname -r`. If it's relative,
 233  *           it's treated as relative to the current working directory.
 234  *           Otherwise, give an absolute dirname.
 235  * @config_paths: ordered array of paths (directories or files) where
 236  *                to load from user-defined configuration parameters such as
 237  *                alias, blacklists, commands (install, remove). If
 238  *                NULL defaults to /run/modprobe.d, /etc/modprobe.d and
 239  *                /lib/modprobe.d. Give an empty vector if configuration should
 240  *                not be read. This array must be null terminated.
 241  *
 242  * Create kmod library context. This reads the kmod configuration
 243  * and fills in the default values.
 244  *
 245  * The initial refcount is 1, and needs to be decremented to
 246  * release the resources of the kmod library context.
 247  *
 248  * Returns: a new kmod library context
 249  */
 250 KMOD_EXPORT struct kmod_ctx *kmod_new(const char *dirname,
 251                                         const char * const *config_paths)
 252 {
 253         const char *env;
 254         struct kmod_ctx *ctx;
 255         int err;
 256
 257         ctx = calloc(1, sizeof(struct kmod_ctx));
 258         if (!ctx)
 259                 return NULL;
 260
 261         ctx->refcount = 1;
 262         ctx->log_fn = log_filep;
 263         ctx->log_data = stderr;
 264         ctx->log_priority = LOG_ERR;
 265
 266         ctx->dirname = get_kernel_release(dirname);
 267
 268         /* environment overwrites config */
 269         env = secure_getenv("KMOD_LOG");
 270         if (env != NULL)
 271                 kmod_set_log_priority(ctx, log_priority(env));
 272
 273         if (config_paths == NULL)
 274                 config_paths = default_config_paths;
 275         err = kmod_config_new(ctx, &ctx->config, config_paths);
 276         if (err < 0) {
 277                 ERR(ctx, "could not create config\n");
 278                 goto fail;
 279         }
 280
 281         ctx->modules_by_name = hash_new(KMOD_HASH_SIZE, NULL);
 282         if (ctx->modules_by_name == NULL) {
 283                 ERR(ctx, "could not create by-name hash\n");
 284                 goto fail;
 285         }
 286
 287         INFO(ctx, "ctx %p created\n", ctx);
 288         DBG(ctx, "log_priority=%d\n", ctx->log_priority);
 289
 290         return ctx;
 291
 292 fail:
 293         free(ctx->modules_by_name);
 294         free(ctx->dirname);
 295         free(ctx);
 296         return NULL;
 297 }
 298
 299 /**
 300  * kmod_ref:
 301  * @ctx: kmod library context
 302  *
 303  * Take a reference of the kmod library context.
 304  *
 305  * Returns: the passed kmod library context
 306  */
 307 KMOD_EXPORT struct kmod_ctx *kmod_ref(struct kmod_ctx *ctx)
 308 {
 309         if (ctx == NULL)
 310                 return NULL;
 311         ctx->refcount++;
 312         return ctx;
 313 }
 314
 315 /**
 316  * kmod_unref:
 317  * @ctx: kmod library context
 318  *
 319  * Drop a reference of the kmod library context. If the refcount
 320  * reaches zero, the resources of the context will be released.
 321  *
 322  * Returns: the passed kmod library context or NULL if it's freed
 323  */
 324 KMOD_EXPORT struct kmod_ctx *kmod_unref(struct kmod_ctx *ctx)
 325 {
 326         if (ctx == NULL)
 327                 return NULL;
 328
 329         if (--ctx->refcount > 0)
 330                 return ctx;
 331
 332         INFO(ctx, "context %p released\n", ctx);
 333
 334         kmod_unload_resources(ctx);
 335         hash_free(ctx->modules_by_name);
 336         free(ctx->dirname);
 337         if (ctx->config)
 338                 kmod_config_free(ctx->config);
 339
 340         free(ctx);
 341         return NULL;
 342 }
 343
 344 /**
 345  * kmod_set_log_fn:
 346  * @ctx: kmod library context
 347  * @log_fn: function to be called for logging messages
 348  * @data: data to pass to log function
 349  *
 350  * The built-in logging writes to stderr. It can be
 351  * overridden by a custom function, to plug log messages
 352  * into the user's logging functionality.
 353  */
 354 KMOD_EXPORT void kmod_set_log_fn(struct kmod_ctx *ctx,
 355                                         void (*log_fn)(void *data,
 356                                                 int priority, const char *file,
 357                                                 int line, const char *fn,
 358                                                 const char *format, va_list args),
 359                                         const void *data)
 360 {
 361         if (ctx == NULL)
 362                 return;
 363         ctx->log_fn = log_fn;
 364         ctx->log_data = (void *)data;
 365         INFO(ctx, "custom logging function %p registered\n", log_fn);
 366 }
 367
 368 /**
 369  * kmod_get_log_priority:
 370  * @ctx: kmod library context
 371  *
 372  * Returns: the current logging priority
 373  */
 374 KMOD_EXPORT int kmod_get_log_priority(const struct kmod_ctx *ctx)
 375 {
 376         if (ctx == NULL)
 377                 return -1;
 378         return ctx->log_priority;
 379 }
 380
 381 /**
 382  * kmod_set_log_priority:
 383  * @ctx: kmod library context
 384  * @priority: the new logging priority
 385  *
 386  * Set the current logging priority. The value controls which messages
 387  * are logged.
 388  */
 389 KMOD_EXPORT void kmod_set_log_priority(struct kmod_ctx *ctx, int priority)
 390 {
 391         if (ctx == NULL)
 392                 return;
 393         ctx->log_priority = priority;
 394 }
 395
 396 struct kmod_module *kmod_pool_get_module(struct kmod_ctx *ctx,
 397                                                         const char *key)
 398 {
 399         struct kmod_module *mod;
 400
 401         mod = hash_find(ctx->modules_by_name, key);
 402
 403         DBG(ctx, "get module name='%s' found=%p\n", key, mod);
 404
 405         return mod;
 406 }
 407
 408 void kmod_pool_add_module(struct kmod_ctx *ctx, struct kmod_module *mod,
 409                                                         const char *key)
 410 {
 411         DBG(ctx, "add %p key='%s'\n", mod, key);
 412
 413         hash_add(ctx->modules_by_name, key, mod);
 414 }
 415
 416 void kmod_pool_del_module(struct kmod_ctx *ctx, struct kmod_module *mod,
 417                                                         const char *key)
 418 {
 419         DBG(ctx, "del %p key='%s'\n", mod, key);
 420
 421         hash_del(ctx->modules_by_name, key);
 422 }
 423
 424 static int kmod_lookup_alias_from_alias_bin(struct kmod_ctx *ctx,
 425                                                 enum kmod_index index_number,
 426                                                 const char *name,
 427                                                 struct kmod_list **list)
 428 {
 429         int err, nmatch = 0;
 430         struct index_file *idx;
 431         struct index_value *realnames, *realname;
 432
 433         if (ctx->indexes[index_number] != NULL) {
 434                 DBG(ctx, "use mmaped index '%s' for name=%s\n",
 435                         index_files[index_number].fn, name);
 436                 realnames = index_mm_searchwild(ctx->indexes[index_number],
 437                                                                         name);
 438         } else {
 439                 char fn[PATH_MAX];
 440
 441                 snprintf(fn, sizeof(fn), "%s/%s.bin", ctx->dirname,
 442                                         index_files[index_number].fn);
 443
 444                 DBG(ctx, "file=%s name=%s\n", fn, name);
 445
 446                 idx = index_file_open(fn);
 447                 if (idx == NULL)
 448                         return -ENOSYS;
 449
 450                 realnames = index_searchwild(idx, name);
 451                 index_file_close(idx);
 452         }
 453
 454         for (realname = realnames; realname; realname = realname->next) {
 455                 struct kmod_module *mod;
 456
 457                 err = kmod_module_new_from_alias(ctx, name, realname->value, &mod);
 458                 if (err < 0) {
 459                         ERR(ctx, "Could not create module for alias=%s realname=%s: %s\n",
 460                             name, realname->value, strerror(-err));
 461                         goto fail;
 462                 }
 463
 464                 *list = kmod_list_append(*list, mod);
 465                 nmatch++;
 466         }
 467
 468         index_values_free(realnames);
 469         return nmatch;
 470
 471 fail:
 472         *list = kmod_list_remove_n_latest(*list, nmatch);
 473         index_values_free(realnames);
 474         return err;
 475
 476 }
 477
 478 int kmod_lookup_alias_from_symbols_file(struct kmod_ctx *ctx, const char *name,
 479                                                 struct kmod_list **list)
 480 {
 481         if (!strstartswith(name, "symbol:"))
 482                 return 0;
 483
 484         return kmod_lookup_alias_from_alias_bin(ctx, KMOD_INDEX_MODULES_SYMBOL,
 485                                                                 name, list);
 486 }
 487
 488 int kmod_lookup_alias_from_aliases_file(struct kmod_ctx *ctx, const char *name,
 489                                                 struct kmod_list **list)
 490 {
 491         return kmod_lookup_alias_from_alias_bin(ctx, KMOD_INDEX_MODULES_ALIAS,
 492                                                                 name, list);
 493 }
 494
 495 static char *lookup_builtin_file(struct kmod_ctx *ctx, const char *name)
 496 {
 497         char *line;
 498
 499         if (ctx->indexes[KMOD_INDEX_MODULES_BUILTIN]) {
 500                 DBG(ctx, "use mmaped index '%s' modname=%s\n",
 501                                 index_files[KMOD_INDEX_MODULES_BUILTIN].fn,
 502                                 name);
 503                 line = index_mm_search(ctx->indexes[KMOD_INDEX_MODULES_BUILTIN],
 504                                                                         name);
 505         } else {
 506                 struct index_file *idx;
 507                 char fn[PATH_MAX];
 508
 509                 snprintf(fn, sizeof(fn), "%s/%s.bin", ctx->dirname,
 510                                 index_files[KMOD_INDEX_MODULES_BUILTIN].fn);
 511                 DBG(ctx, "file=%s modname=%s\n", fn, name);
 512
 513                 idx = index_file_open(fn);
 514                 if (idx == NULL) {
 515                         DBG(ctx, "could not open builtin file '%s'\n", fn);
 516                         return NULL;
 517                 }
 518
 519                 line = index_search(idx, name);
 520                 index_file_close(idx);
 521         }
 522
 523         return line;
 524 }
 525
 526 int kmod_lookup_alias_from_kernel_builtin_file(struct kmod_ctx *ctx,
 527                                                 const char *name,
 528                                                 struct kmod_list **list)
 529 {
 530         struct kmod_list *l;
 531         int ret;
 532
 533         assert(*list == NULL);
 534
 535         ret = kmod_lookup_alias_from_alias_bin(ctx,
 536                                                KMOD_INDEX_MODULES_BUILTIN_ALIAS,
 537                                                name, list);
 538
 539         kmod_list_foreach(l, *list) {
 540                 struct kmod_module *mod = l->data;
 541                 kmod_module_set_builtin(mod, true);
 542         }
 543
 544         return ret;
 545 }
 546
 547 int kmod_lookup_alias_from_builtin_file(struct kmod_ctx *ctx, const char *name,
 548                                                 struct kmod_list **list)
 549 {
 550         char *line;
 551         int err = 0;
 552
 553         assert(*list == NULL);
 554
 555         line = lookup_builtin_file(ctx, name);
 556         if (line != NULL) {
 557                 struct kmod_module *mod;
 558
 559                 err = kmod_module_new_from_name(ctx, name, &mod);
 560                 if (err < 0) {
 561                         ERR(ctx, "Could not create module from name %s: %s\n",
 562                                                         name, strerror(-err));
 563                         goto finish;
 564                 }
 565
 566                 /* already mark it as builtin since it's being created from
 567                  * this index */
 568                 kmod_module_set_builtin(mod, true);
 569                 *list = kmod_list_append(*list, mod);
 570                 if (*list == NULL)
 571                         err = -ENOMEM;
 572         }
 573
 574 finish:
 575         free(line);
 576         return err;
 577 }
 578
 579 bool kmod_lookup_alias_is_builtin(struct kmod_ctx *ctx, const char *name)
 580 {
 581         _cleanup_free_ char *line;
 582
 583         line = lookup_builtin_file(ctx, name);
 584
 585         return line != NULL;
 586 }
 587
 588 char *kmod_search_moddep(struct kmod_ctx *ctx, const char *name)
 589 {
 590         struct index_file *idx;
 591         char fn[PATH_MAX];
 592         char *line;
 593
 594         if (ctx->indexes[KMOD_INDEX_MODULES_DEP]) {
 595                 DBG(ctx, "use mmaped index '%s' modname=%s\n",
 596                                 index_files[KMOD_INDEX_MODULES_DEP].fn, name);
 597                 return index_mm_search(ctx->indexes[KMOD_INDEX_MODULES_DEP],
 598                                                                         name);
 599         }
 600
 601         snprintf(fn, sizeof(fn), "%s/%s.bin", ctx->dirname,
 602                                         index_files[KMOD_INDEX_MODULES_DEP].fn);
 603
 604         DBG(ctx, "file=%s modname=%s\n", fn, name);
 605
 606         idx = index_file_open(fn);
 607         if (idx == NULL) {
 608                 DBG(ctx, "could not open moddep file '%s'\n", fn);
 609                 return NULL;
 610         }
 611
 612         line = index_search(idx, name);
 613         index_file_close(idx);
 614
 615         return line;
 616 }
 617
 618 int kmod_lookup_alias_from_moddep_file(struct kmod_ctx *ctx, const char *name,
 619                                                 struct kmod_list **list)
 620 {
 621         char *line;
 622         int n = 0;
 623
 624         /*
 625          * Module names do not contain ':'. Return early if we know it will
 626          * not be found.
 627          */
 628         if (strchr(name, ':'))
 629                 return 0;
 630
 631         line = kmod_search_moddep(ctx, name);
 632         if (line != NULL) {
 633                 struct kmod_module *mod;
 634
 635                 n = kmod_module_new_from_name(ctx, name, &mod);
 636                 if (n < 0) {
 637                         ERR(ctx, "Could not create module from name %s: %s\n",
 638                             name, strerror(-n));
 639                         goto finish;
 640                 }
 641
 642                 *list = kmod_list_append(*list, mod);
 643                 kmod_module_parse_depline(mod, line);
 644         }
 645
 646 finish:
 647         free(line);
 648
 649         return n;
 650 }
 651
 652 int kmod_lookup_alias_from_config(struct kmod_ctx *ctx, const char *name,
 653                                                 struct kmod_list **list)
 654 {
 655         struct kmod_config *config = ctx->config;
 656         struct kmod_list *l;
 657         int err, nmatch = 0;
 658
 659         kmod_list_foreach(l, config->aliases) {
 660                 const char *aliasname = kmod_alias_get_name(l);
 661                 const char *modname = kmod_alias_get_modname(l);
 662
 663                 if (fnmatch(aliasname, name, 0) == 0) {
 664                         struct kmod_module *mod;
 665
 666                         err = kmod_module_new_from_alias(ctx, aliasname,
 667                                                                 modname, &mod);
 668                         if (err < 0) {
 669                                 ERR(ctx, "Could not create module for alias=%s modname=%s: %s\n",
 670                                     name, modname, strerror(-err));
 671                                 goto fail;
 672                         }
 673
 674                         *list = kmod_list_append(*list, mod);
 675                         nmatch++;
 676                 }
 677         }
 678
 679         return nmatch;
 680
 681 fail:
 682         *list = kmod_list_remove_n_latest(*list, nmatch);
 683         return err;
 684 }
 685
 686 int kmod_lookup_alias_from_commands(struct kmod_ctx *ctx, const char *name,
 687                                                 struct kmod_list **list)
 688 {
 689         struct kmod_config *config = ctx->config;
 690         struct kmod_list *l, *node;
 691         int err, nmatch = 0;
 692
 693         kmod_list_foreach(l, config->install_commands) {
 694                 const char *modname = kmod_command_get_modname(l);
 695
 696                 if (streq(modname, name)) {
 697                         const char *cmd = kmod_command_get_command(l);
 698                         struct kmod_module *mod;
 699
 700                         err = kmod_module_new_from_name(ctx, modname, &mod);
 701                         if (err < 0) {
 702                                 ERR(ctx, "Could not create module from name %s: %s\n",
 703                                     modname, strerror(-err));
 704                                 return err;
 705                         }
 706
 707                         node = kmod_list_append(*list, mod);
 708                         if (node == NULL) {
 709                                 ERR(ctx, "out of memory\n");
 710                                 return -ENOMEM;
 711                         }
 712
 713                         *list = node;
 714                         nmatch = 1;
 715
 716                         kmod_module_set_install_commands(mod, cmd);
 717
 718                         /*
 719                          * match only the first one, like modprobe from
 720                          * module-init-tools does
 721                          */
 722                         break;
 723                 }
 724         }
 725
 726         if (nmatch)
 727                 return nmatch;
 728
 729         kmod_list_foreach(l, config->remove_commands) {
 730                 const char *modname = kmod_command_get_modname(l);
 731
 732                 if (streq(modname, name)) {
 733                         const char *cmd = kmod_command_get_command(l);
 734                         struct kmod_module *mod;
 735
 736                         err = kmod_module_new_from_name(ctx, modname, &mod);
 737                         if (err < 0) {
 738                                 ERR(ctx, "Could not create module from name %s: %s\n",
 739                                     modname, strerror(-err));
 740                                 return err;
 741                         }
 742
 743                         node = kmod_list_append(*list, mod);
 744                         if (node == NULL) {
 745                                 ERR(ctx, "out of memory\n");
 746                                 return -ENOMEM;
 747                         }
 748
 749                         *list = node;
 750                         nmatch = 1;
 751
 752                         kmod_module_set_remove_commands(mod, cmd);
 753
 754                         /*
 755                          * match only the first one, like modprobe from
 756                          * module-init-tools does
 757                          */
 758                         break;
 759                 }
 760         }
 761
 762         return nmatch;
 763 }
 764
 765 void kmod_set_modules_visited(struct kmod_ctx *ctx, bool visited)
 766 {
 767         struct hash_iter iter;
 768         const void *v;
 769
 770         hash_iter_init(ctx->modules_by_name, &iter);
 771         while (hash_iter_next(&iter, NULL, &v))
 772                 kmod_module_set_visited((struct kmod_module *)v, visited);
 773 }
 774
 775 void kmod_set_modules_required(struct kmod_ctx *ctx, bool required)
 776 {
 777         struct hash_iter iter;
 778         const void *v;
 779
 780         hash_iter_init(ctx->modules_by_name, &iter);
 781         while (hash_iter_next(&iter, NULL, &v))
 782                 kmod_module_set_required((struct kmod_module *)v, required);
 783 }
 784
 785 static bool is_cache_invalid(const char *path, unsigned long long stamp)
 786 {
 787         struct stat st;
 788
 789         if (stat(path, &st) < 0)
 790                 return true;
 791
 792         if (stamp != stat_mstamp(&st))
 793                 return true;
 794
 795         return false;
 796 }
 797
 798 /**
 799  * kmod_validate_resources:
 800  * @ctx: kmod library context
 801  *
 802  * Check if indexes and configuration files changed on disk and the current
 803  * context is not valid anymore.
 804  *
 805  * Returns: KMOD_RESOURCES_OK if resources are still valid,
 806  * KMOD_RESOURCES_MUST_RELOAD if it's sufficient to call
 807  * kmod_unload_resources() and kmod_load_resources() or
 808  * KMOD_RESOURCES_MUST_RECREATE if @ctx must be re-created.
 809  */
 810 KMOD_EXPORT int kmod_validate_resources(struct kmod_ctx *ctx)
 811 {
 812         struct kmod_list *l;
 813         size_t i;
 814
 815         if (ctx == NULL || ctx->config == NULL)
 816                 return KMOD_RESOURCES_MUST_RECREATE;
 817
 818         kmod_list_foreach(l, ctx->config->paths) {
 819                 struct kmod_config_path *cf = l->data;
 820
 821                 if (is_cache_invalid(cf->path, cf->stamp))
 822                         return KMOD_RESOURCES_MUST_RECREATE;
 823         }
 824
 825         for (i = 0; i < _KMOD_INDEX_MODULES_SIZE; i++) {
 826                 char path[PATH_MAX];
 827
 828                 if (ctx->indexes[i] == NULL)
 829                         continue;
 830
 831                 snprintf(path, sizeof(path), "%s/%s.bin", ctx->dirname,
 832                                                 index_files[i].fn);
 833
 834                 if (is_cache_invalid(path, ctx->indexes_stamp[i]))
 835                         return KMOD_RESOURCES_MUST_RELOAD;
 836         }
 837
 838         return KMOD_RESOURCES_OK;
 839 }
 840
 841 /**
 842  * kmod_load_resources:
 843  * @ctx: kmod library context
 844  *
 845  * Load indexes and keep them open in @ctx. This way it's faster to lookup
 846  * information within the indexes. If this function is not called before a
 847  * search, the necessary index is always opened and closed.
 848  *
 849  * If user will do more than one or two lookups, insertions, deletions, most
 850  * likely it's good to call this function first. Particularly in a daemon like
 851  * udev that on bootup issues hundreds of calls to lookup the index, calling
 852  * this function will speedup the searches.
 853  *
 854  * Returns: 0 on success or < 0 otherwise.
 855  */
 856 KMOD_EXPORT int kmod_load_resources(struct kmod_ctx *ctx)
 857 {
 858         size_t i;
 859
 860         if (ctx == NULL)
 861                 return -ENOENT;
 862
 863         for (i = 0; i < _KMOD_INDEX_MODULES_SIZE; i++) {
 864                 char path[PATH_MAX];
 865
 866                 if (ctx->indexes[i] != NULL) {
 867                         INFO(ctx, "Index %s already loaded\n",
 868                                                         index_files[i].fn);
 869                         continue;
 870                 }
 871
 872                 snprintf(path, sizeof(path), "%s/%s.bin", ctx->dirname,
 873                                                         index_files[i].fn);
 874                 ctx->indexes[i] = index_mm_open(ctx, path,
 875                                                 &ctx->indexes_stamp[i]);
 876                 if (ctx->indexes[i] == NULL)
 877                         goto fail;
 878         }
 879
 880         return 0;
 881
 882 fail:
 883         kmod_unload_resources(ctx);
 884         return -ENOMEM;
 885 }
 886
 887 /**
 888  * kmod_unload_resources:
 889  * @ctx: kmod library context
 890  *
 891  * Unload all the indexes. This will free the resources to maintain the index
 892  * open and all subsequent searches will need to open and close the index.
 893  *
 894  * User is free to call kmod_load_resources() and kmod_unload_resources() as
 895  * many times as wanted during the lifecycle of @ctx. For example, if a daemon
 896  * knows that when starting up it will lookup a lot of modules, it could call
 897  * kmod_load_resources() and after the first burst of searches is gone, it
 898  * could free the resources by calling kmod_unload_resources().
 899  *
 900  * Returns: 0 on success or < 0 otherwise.
 901  */
 902 KMOD_EXPORT void kmod_unload_resources(struct kmod_ctx *ctx)
 903 {
 904         size_t i;
 905
 906         if (ctx == NULL)
 907                 return;
 908
 909         for (i = 0; i < _KMOD_INDEX_MODULES_SIZE; i++) {
 910                 if (ctx->indexes[i] != NULL) {
 911                         index_mm_close(ctx->indexes[i]);
 912                         ctx->indexes[i] = NULL;
 913                         ctx->indexes_stamp[i] = 0;
 914                 }
 915         }
 916 }
 917
 918 /**
 919  * kmod_dump_index:
 920  * @ctx: kmod library context
 921  * @type: index to dump, valid indexes are
 922  * KMOD_INDEX_MODULES_DEP: index of module dependencies;
 923  * KMOD_INDEX_MODULES_ALIAS: index of module aliases;
 924  * KMOD_INDEX_MODULES_SYMBOL: index of symbol aliases;
 925  * KMOD_INDEX_MODULES_BUILTIN: index of builtin module.
 926  * @fd: file descriptor to dump index to
 927  *
 928  * Dump index to file descriptor. Note that this function doesn't use stdio.h
 929  * so call fflush() before calling this function to be sure data is written in
 930  * order.
 931  *
 932  * Returns: 0 on success or < 0 otherwise.
 933  */
 934 KMOD_EXPORT int kmod_dump_index(struct kmod_ctx *ctx, enum kmod_index type,
 935                                                                         int fd)
 936 {
 937         if (ctx == NULL)
 938                 return -ENOSYS;
 939
 940         if (type < 0 || type >= _KMOD_INDEX_MODULES_SIZE)
 941                 return -ENOENT;
 942
 943         if (ctx->indexes[type] != NULL) {
 944                 DBG(ctx, "use mmaped index '%s'\n", index_files[type].fn);
 945                 index_mm_dump(ctx->indexes[type], fd,
 946                                                 index_files[type].prefix);
 947         } else {
 948                 char fn[PATH_MAX];
 949                 struct index_file *idx;
 950
 951                 snprintf(fn, sizeof(fn), "%s/%s.bin", ctx->dirname,
 952                                                 index_files[type].fn);
 953
 954                 DBG(ctx, "file=%s\n", fn);
 955
 956                 idx = index_file_open(fn);
 957                 if (idx == NULL)
 958                         return -ENOSYS;
 959
 960                 index_dump(idx, fd, index_files[type].prefix);
 961                 index_file_close(idx);
 962         }
 963
 964         return 0;
 965 }
 966
 967 const struct kmod_config *kmod_get_config(const struct kmod_ctx *ctx)
 968 {
 969         return ctx->config;
 970 }