2 * libkmod - interface to kernel module operations
4 * Copyright (C) 2011-2013 ProFUSION embedded systems
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.
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.
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/>.
32 #include <sys/utsname.h>
34 #include <shared/hash.h>
35 #include <shared/util.h>
38 #include "libkmod-internal.h"
39 #include "libkmod-index.h"
41 #define KMOD_HASH_SIZE (256)
42 #define KMOD_LRU_MAX (128)
43 #define _KMOD_INDEX_MODULES_SIZE KMOD_INDEX_MODULES_BUILTIN + 1
47 * @short_description: libkmod context
49 * The context contains the default values for the library user,
50 * and is passed to all library operations.
53 static struct _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 = ""},
64 static const char *default_config_paths[] = {
65 SYSCONFDIR "/modprobe.d",
74 * Opaque object representing the library context.
79 void (*log_fn)(void *data,
80 int priority, const char *file, int line,
81 const char *fn, const char *format, va_list args);
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];
91 void kmod_log(const struct kmod_ctx *ctx,
92 int priority, const char *file, int line, const char *fn,
93 const char *format, ...)
97 if (ctx->log_fn == NULL)
100 va_start(args, format);
101 ctx->log_fn(ctx->log_data, priority, file, line, fn, format, args);
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)
116 priname = "EMERGENCY";
122 priname = "CRITICAL";
140 snprintf(buf, sizeof(buf), "L:%d", priority);
143 fprintf(fp, "libkmod: %s %s:%d %s: ", priname, file, line, fn);
145 fprintf(fp, "libkmod: %s: ", fn);
147 vfprintf(fp, format, args);
153 * @ctx: kmod library context
155 * Retrieve the absolute path used for linux modules in this context. The path
156 * is computed from the arguments to kmod_new().
158 KMOD_EXPORT const char *kmod_get_dirname(const struct kmod_ctx *ctx)
165 * @ctx: kmod library context
167 * Retrieve stored data pointer from library context. This might be useful
168 * to access from callbacks.
170 * Returns: stored userdata
172 KMOD_EXPORT void *kmod_get_userdata(const struct kmod_ctx *ctx)
176 return (void *)ctx->userdata;
181 * @ctx: kmod library context
182 * @userdata: data pointer
184 * Store custom @userdata in the library context.
186 KMOD_EXPORT void kmod_set_userdata(struct kmod_ctx *ctx, const void *userdata)
190 ctx->userdata = userdata;
193 static int log_priority(const char *priority)
198 prio = strtol(priority, &endptr, 10);
199 if (endptr[0] == '\0' || isspace(endptr[0]))
201 if (strncmp(priority, "err", 3) == 0)
203 if (strncmp(priority, "info", 4) == 0)
205 if (strncmp(priority, "debug", 5) == 0)
210 static const char *dirname_default_prefix = "/lib/modules";
212 static char *get_kernel_release(const char *dirname)
218 return path_make_absolute_cwd(dirname);
223 if (asprintf(&p, "%s/%s", dirname_default_prefix, u.release) < 0)
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.
242 * Create kmod library context. This reads the kmod configuration
243 * and fills in the default values.
245 * The initial refcount is 1, and needs to be decremented to
246 * release the resources of the kmod library context.
248 * Returns: a new kmod library context
250 KMOD_EXPORT struct kmod_ctx *kmod_new(const char *dirname,
251 const char * const *config_paths)
254 struct kmod_ctx *ctx;
257 ctx = calloc(1, sizeof(struct kmod_ctx));
262 ctx->log_fn = log_filep;
263 ctx->log_data = stderr;
264 ctx->log_priority = LOG_ERR;
266 ctx->dirname = get_kernel_release(dirname);
268 /* environment overwrites config */
269 env = secure_getenv("KMOD_LOG");
271 kmod_set_log_priority(ctx, log_priority(env));
273 if (config_paths == NULL)
274 config_paths = default_config_paths;
275 err = kmod_config_new(ctx, &ctx->config, config_paths);
277 ERR(ctx, "could not create config\n");
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");
287 INFO(ctx, "ctx %p created\n", ctx);
288 DBG(ctx, "log_priority=%d\n", ctx->log_priority);
293 free(ctx->modules_by_name);
301 * @ctx: kmod library context
303 * Take a reference of the kmod library context.
305 * Returns: the passed kmod library context
307 KMOD_EXPORT struct kmod_ctx *kmod_ref(struct kmod_ctx *ctx)
317 * @ctx: kmod library context
319 * Drop a reference of the kmod library context. If the refcount
320 * reaches zero, the resources of the context will be released.
322 * Returns: the passed kmod library context or NULL if it's freed
324 KMOD_EXPORT struct kmod_ctx *kmod_unref(struct kmod_ctx *ctx)
329 if (--ctx->refcount > 0)
332 INFO(ctx, "context %p released\n", ctx);
334 kmod_unload_resources(ctx);
335 hash_free(ctx->modules_by_name);
338 kmod_config_free(ctx->config);
346 * @ctx: kmod library context
347 * @log_fn: function to be called for logging messages
348 * @data: data to pass to log function
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.
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),
363 ctx->log_fn = log_fn;
364 ctx->log_data = (void *)data;
365 INFO(ctx, "custom logging function %p registered\n", log_fn);
369 * kmod_get_log_priority:
370 * @ctx: kmod library context
372 * Returns: the current logging priority
374 KMOD_EXPORT int kmod_get_log_priority(const struct kmod_ctx *ctx)
378 return ctx->log_priority;
382 * kmod_set_log_priority:
383 * @ctx: kmod library context
384 * @priority: the new logging priority
386 * Set the current logging priority. The value controls which messages
389 KMOD_EXPORT void kmod_set_log_priority(struct kmod_ctx *ctx, int priority)
393 ctx->log_priority = priority;
396 struct kmod_module *kmod_pool_get_module(struct kmod_ctx *ctx,
399 struct kmod_module *mod;
401 mod = hash_find(ctx->modules_by_name, key);
403 DBG(ctx, "get module name='%s' found=%p\n", key, mod);
408 void kmod_pool_add_module(struct kmod_ctx *ctx, struct kmod_module *mod,
411 DBG(ctx, "add %p key='%s'\n", mod, key);
413 hash_add(ctx->modules_by_name, key, mod);
416 void kmod_pool_del_module(struct kmod_ctx *ctx, struct kmod_module *mod,
419 DBG(ctx, "del %p key='%s'\n", mod, key);
421 hash_del(ctx->modules_by_name, key);
424 static int kmod_lookup_alias_from_alias_bin(struct kmod_ctx *ctx,
425 enum kmod_index index_number,
427 struct kmod_list **list)
430 struct index_file *idx;
431 struct index_value *realnames, *realname;
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],
441 snprintf(fn, sizeof(fn), "%s/%s.bin", ctx->dirname,
442 index_files[index_number].fn);
444 DBG(ctx, "file=%s name=%s\n", fn, name);
446 idx = index_file_open(fn);
450 realnames = index_searchwild(idx, name);
451 index_file_close(idx);
454 for (realname = realnames; realname; realname = realname->next) {
455 struct kmod_module *mod;
457 err = kmod_module_new_from_alias(ctx, name, realname->value, &mod);
459 ERR(ctx, "Could not create module for alias=%s realname=%s: %s\n",
460 name, realname->value, strerror(-err));
464 *list = kmod_list_append(*list, mod);
468 index_values_free(realnames);
472 *list = kmod_list_remove_n_latest(*list, nmatch);
473 index_values_free(realnames);
478 int kmod_lookup_alias_from_symbols_file(struct kmod_ctx *ctx, const char *name,
479 struct kmod_list **list)
481 if (!strstartswith(name, "symbol:"))
484 return kmod_lookup_alias_from_alias_bin(ctx, KMOD_INDEX_MODULES_SYMBOL,
488 int kmod_lookup_alias_from_aliases_file(struct kmod_ctx *ctx, const char *name,
489 struct kmod_list **list)
491 return kmod_lookup_alias_from_alias_bin(ctx, KMOD_INDEX_MODULES_ALIAS,
495 static char *lookup_builtin_file(struct kmod_ctx *ctx, const char *name)
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,
503 line = index_mm_search(ctx->indexes[KMOD_INDEX_MODULES_BUILTIN],
506 struct index_file *idx;
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);
513 idx = index_file_open(fn);
515 DBG(ctx, "could not open builtin file '%s'\n", fn);
519 line = index_search(idx, name);
520 index_file_close(idx);
526 int kmod_lookup_alias_from_kernel_builtin_file(struct kmod_ctx *ctx,
528 struct kmod_list **list)
531 int ret = kmod_lookup_alias_from_alias_bin(ctx,
532 KMOD_INDEX_MODULES_BUILTIN_ALIAS,
535 kmod_list_foreach(l, *list) {
536 struct kmod_module *mod = l->data;
537 kmod_module_set_builtin(mod, true);
539 } else if (ret == -ENOSYS) {
541 * If the system does not support this yet, then
542 * there is no need to return an error.
550 int kmod_lookup_alias_from_builtin_file(struct kmod_ctx *ctx, const char *name,
551 struct kmod_list **list)
556 assert(*list == NULL);
558 line = lookup_builtin_file(ctx, name);
560 struct kmod_module *mod;
562 err = kmod_module_new_from_name(ctx, name, &mod);
564 ERR(ctx, "Could not create module from name %s: %s\n",
565 name, strerror(-err));
569 /* already mark it as builtin since it's being created from
571 kmod_module_set_builtin(mod, true);
572 *list = kmod_list_append(*list, mod);
582 bool kmod_lookup_alias_is_builtin(struct kmod_ctx *ctx, const char *name)
584 _cleanup_free_ char *line;
586 line = lookup_builtin_file(ctx, name);
591 char *kmod_search_moddep(struct kmod_ctx *ctx, const char *name)
593 struct index_file *idx;
597 if (ctx->indexes[KMOD_INDEX_MODULES_DEP]) {
598 DBG(ctx, "use mmaped index '%s' modname=%s\n",
599 index_files[KMOD_INDEX_MODULES_DEP].fn, name);
600 return index_mm_search(ctx->indexes[KMOD_INDEX_MODULES_DEP],
604 snprintf(fn, sizeof(fn), "%s/%s.bin", ctx->dirname,
605 index_files[KMOD_INDEX_MODULES_DEP].fn);
607 DBG(ctx, "file=%s modname=%s\n", fn, name);
609 idx = index_file_open(fn);
611 DBG(ctx, "could not open moddep file '%s'\n", fn);
615 line = index_search(idx, name);
616 index_file_close(idx);
621 int kmod_lookup_alias_from_moddep_file(struct kmod_ctx *ctx, const char *name,
622 struct kmod_list **list)
628 * Module names do not contain ':'. Return early if we know it will
631 if (strchr(name, ':'))
634 line = kmod_search_moddep(ctx, name);
636 struct kmod_module *mod;
638 n = kmod_module_new_from_name(ctx, name, &mod);
640 ERR(ctx, "Could not create module from name %s: %s\n",
645 *list = kmod_list_append(*list, mod);
646 kmod_module_parse_depline(mod, line);
655 int kmod_lookup_alias_from_config(struct kmod_ctx *ctx, const char *name,
656 struct kmod_list **list)
658 struct kmod_config *config = ctx->config;
662 kmod_list_foreach(l, config->aliases) {
663 const char *aliasname = kmod_alias_get_name(l);
664 const char *modname = kmod_alias_get_modname(l);
666 if (fnmatch(aliasname, name, 0) == 0) {
667 struct kmod_module *mod;
669 err = kmod_module_new_from_alias(ctx, aliasname,
672 ERR(ctx, "Could not create module for alias=%s modname=%s: %s\n",
673 name, modname, strerror(-err));
677 *list = kmod_list_append(*list, mod);
685 *list = kmod_list_remove_n_latest(*list, nmatch);
689 int kmod_lookup_alias_from_commands(struct kmod_ctx *ctx, const char *name,
690 struct kmod_list **list)
692 struct kmod_config *config = ctx->config;
693 struct kmod_list *l, *node;
696 kmod_list_foreach(l, config->install_commands) {
697 const char *modname = kmod_command_get_modname(l);
699 if (streq(modname, name)) {
700 const char *cmd = kmod_command_get_command(l);
701 struct kmod_module *mod;
703 err = kmod_module_new_from_name(ctx, modname, &mod);
705 ERR(ctx, "Could not create module from name %s: %s\n",
706 modname, strerror(-err));
710 node = kmod_list_append(*list, mod);
712 ERR(ctx, "out of memory\n");
719 kmod_module_set_install_commands(mod, cmd);
722 * match only the first one, like modprobe from
723 * module-init-tools does
732 kmod_list_foreach(l, config->remove_commands) {
733 const char *modname = kmod_command_get_modname(l);
735 if (streq(modname, name)) {
736 const char *cmd = kmod_command_get_command(l);
737 struct kmod_module *mod;
739 err = kmod_module_new_from_name(ctx, modname, &mod);
741 ERR(ctx, "Could not create module from name %s: %s\n",
742 modname, strerror(-err));
746 node = kmod_list_append(*list, mod);
748 ERR(ctx, "out of memory\n");
755 kmod_module_set_remove_commands(mod, cmd);
758 * match only the first one, like modprobe from
759 * module-init-tools does
768 void kmod_set_modules_visited(struct kmod_ctx *ctx, bool visited)
770 struct hash_iter iter;
773 hash_iter_init(ctx->modules_by_name, &iter);
774 while (hash_iter_next(&iter, NULL, &v))
775 kmod_module_set_visited((struct kmod_module *)v, visited);
778 void kmod_set_modules_required(struct kmod_ctx *ctx, bool required)
780 struct hash_iter iter;
783 hash_iter_init(ctx->modules_by_name, &iter);
784 while (hash_iter_next(&iter, NULL, &v))
785 kmod_module_set_required((struct kmod_module *)v, required);
788 static bool is_cache_invalid(const char *path, unsigned long long stamp)
792 if (stat(path, &st) < 0)
795 if (stamp != stat_mstamp(&st))
802 * kmod_validate_resources:
803 * @ctx: kmod library context
805 * Check if indexes and configuration files changed on disk and the current
806 * context is not valid anymore.
808 * Returns: KMOD_RESOURCES_OK if resources are still valid,
809 * KMOD_RESOURCES_MUST_RELOAD if it's sufficient to call
810 * kmod_unload_resources() and kmod_load_resources() or
811 * KMOD_RESOURCES_MUST_RECREATE if @ctx must be re-created.
813 KMOD_EXPORT int kmod_validate_resources(struct kmod_ctx *ctx)
818 if (ctx == NULL || ctx->config == NULL)
819 return KMOD_RESOURCES_MUST_RECREATE;
821 kmod_list_foreach(l, ctx->config->paths) {
822 struct kmod_config_path *cf = l->data;
824 if (is_cache_invalid(cf->path, cf->stamp))
825 return KMOD_RESOURCES_MUST_RECREATE;
828 for (i = 0; i < _KMOD_INDEX_MODULES_SIZE; i++) {
831 if (ctx->indexes[i] == NULL)
834 snprintf(path, sizeof(path), "%s/%s.bin", ctx->dirname,
837 if (is_cache_invalid(path, ctx->indexes_stamp[i]))
838 return KMOD_RESOURCES_MUST_RELOAD;
841 return KMOD_RESOURCES_OK;
845 * kmod_load_resources:
846 * @ctx: kmod library context
848 * Load indexes and keep them open in @ctx. This way it's faster to lookup
849 * information within the indexes. If this function is not called before a
850 * search, the necessary index is always opened and closed.
852 * If user will do more than one or two lookups, insertions, deletions, most
853 * likely it's good to call this function first. Particularly in a daemon like
854 * udev that on bootup issues hundreds of calls to lookup the index, calling
855 * this function will speedup the searches.
857 * Returns: 0 on success or < 0 otherwise.
859 KMOD_EXPORT int kmod_load_resources(struct kmod_ctx *ctx)
866 for (i = 0; i < _KMOD_INDEX_MODULES_SIZE; i++) {
869 if (ctx->indexes[i] != NULL) {
870 INFO(ctx, "Index %s already loaded\n",
875 snprintf(path, sizeof(path), "%s/%s.bin", ctx->dirname,
877 ctx->indexes[i] = index_mm_open(ctx, path,
878 &ctx->indexes_stamp[i]);
879 if (ctx->indexes[i] == NULL)
886 kmod_unload_resources(ctx);
891 * kmod_unload_resources:
892 * @ctx: kmod library context
894 * Unload all the indexes. This will free the resources to maintain the index
895 * open and all subsequent searches will need to open and close the index.
897 * User is free to call kmod_load_resources() and kmod_unload_resources() as
898 * many times as wanted during the lifecycle of @ctx. For example, if a daemon
899 * knows that when starting up it will lookup a lot of modules, it could call
900 * kmod_load_resources() and after the first burst of searches is gone, it
901 * could free the resources by calling kmod_unload_resources().
903 * Returns: 0 on success or < 0 otherwise.
905 KMOD_EXPORT void kmod_unload_resources(struct kmod_ctx *ctx)
912 for (i = 0; i < _KMOD_INDEX_MODULES_SIZE; i++) {
913 if (ctx->indexes[i] != NULL) {
914 index_mm_close(ctx->indexes[i]);
915 ctx->indexes[i] = NULL;
916 ctx->indexes_stamp[i] = 0;
923 * @ctx: kmod library context
924 * @type: index to dump, valid indexes are
925 * KMOD_INDEX_MODULES_DEP: index of module dependencies;
926 * KMOD_INDEX_MODULES_ALIAS: index of module aliases;
927 * KMOD_INDEX_MODULES_SYMBOL: index of symbol aliases;
928 * KMOD_INDEX_MODULES_BUILTIN: index of builtin module.
929 * @fd: file descriptor to dump index to
931 * Dump index to file descriptor. Note that this function doesn't use stdio.h
932 * so call fflush() before calling this function to be sure data is written in
935 * Returns: 0 on success or < 0 otherwise.
937 KMOD_EXPORT int kmod_dump_index(struct kmod_ctx *ctx, enum kmod_index type,
943 if (type < 0 || type >= _KMOD_INDEX_MODULES_SIZE)
946 if (ctx->indexes[type] != NULL) {
947 DBG(ctx, "use mmaped index '%s'\n", index_files[type].fn);
948 index_mm_dump(ctx->indexes[type], fd,
949 index_files[type].prefix);
952 struct index_file *idx;
954 snprintf(fn, sizeof(fn), "%s/%s.bin", ctx->dirname,
955 index_files[type].fn);
957 DBG(ctx, "file=%s\n", fn);
959 idx = index_file_open(fn);
963 index_dump(idx, fd, index_files[type].prefix);
964 index_file_close(idx);
970 const struct kmod_config *kmod_get_config(const struct kmod_ctx *ctx)