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
] = { .fn
= "modules.builtin", .prefix
= ""},
63 static const char *default_config_paths
[] = {
64 SYSCONFDIR
"/modprobe.d",
73 * Opaque object representing the library context.
78 void (*log_fn
)(void *data
,
79 int priority
, const char *file
, int line
,
80 const char *fn
, const char *format
, va_list args
);
84 struct kmod_config
*config
;
85 struct hash
*modules_by_name
;
86 struct index_mm
*indexes
[_KMOD_INDEX_MODULES_SIZE
];
87 unsigned long long indexes_stamp
[_KMOD_INDEX_MODULES_SIZE
];
90 void kmod_log(const struct kmod_ctx
*ctx
,
91 int priority
, const char *file
, int line
, const char *fn
,
92 const char *format
, ...)
96 if (ctx
->log_fn
== NULL
)
99 va_start(args
, format
);
100 ctx
->log_fn(ctx
->log_data
, priority
, file
, line
, fn
, format
, args
);
104 _printf_format_(6, 0)
105 static void log_filep(void *data
,
106 int priority
, const char *file
, int line
,
107 const char *fn
, const char *format
, va_list args
)
115 priname
= "EMERGENCY";
121 priname
= "CRITICAL";
139 snprintf(buf
, sizeof(buf
), "L:%d", priority
);
142 fprintf(fp
, "libkmod: %s %s:%d %s: ", priname
, file
, line
, fn
);
144 fprintf(fp
, "libkmod: %s: ", fn
);
146 vfprintf(fp
, format
, args
);
152 * @ctx: kmod library context
154 * Retrieve the absolute path used for linux modules in this context. The path
155 * is computed from the arguments to kmod_new().
157 KMOD_EXPORT
const char *kmod_get_dirname(const struct kmod_ctx
*ctx
)
164 * @ctx: kmod library context
166 * Retrieve stored data pointer from library context. This might be useful
167 * to access from callbacks.
169 * Returns: stored userdata
171 KMOD_EXPORT
void *kmod_get_userdata(const struct kmod_ctx
*ctx
)
175 return (void *)ctx
->userdata
;
180 * @ctx: kmod library context
181 * @userdata: data pointer
183 * Store custom @userdata in the library context.
185 KMOD_EXPORT
void kmod_set_userdata(struct kmod_ctx
*ctx
, const void *userdata
)
189 ctx
->userdata
= userdata
;
192 static int log_priority(const char *priority
)
197 prio
= strtol(priority
, &endptr
, 10);
198 if (endptr
[0] == '\0' || isspace(endptr
[0]))
200 if (strncmp(priority
, "err", 3) == 0)
202 if (strncmp(priority
, "info", 4) == 0)
204 if (strncmp(priority
, "debug", 5) == 0)
209 static const char *dirname_default_prefix
= "/lib/modules";
211 static char *get_kernel_release(const char *dirname
)
217 return path_make_absolute_cwd(dirname
);
222 if (asprintf(&p
, "%s/%s", dirname_default_prefix
, u
.release
) < 0)
230 * @dirname: what to consider as linux module's directory, if NULL
231 * defaults to /lib/modules/`uname -r`. If it's relative,
232 * it's treated as relative to the current working directory.
233 * Otherwise, give an absolute dirname.
234 * @config_paths: ordered array of paths (directories or files) where
235 * to load from user-defined configuration parameters such as
236 * alias, blacklists, commands (install, remove). If
237 * NULL defaults to /run/modprobe.d, /etc/modprobe.d and
238 * /lib/modprobe.d. Give an empty vector if configuration should
239 * not be read. This array must be null terminated.
241 * Create kmod library context. This reads the kmod configuration
242 * and fills in the default values.
244 * The initial refcount is 1, and needs to be decremented to
245 * release the resources of the kmod library context.
247 * Returns: a new kmod library context
249 KMOD_EXPORT
struct kmod_ctx
*kmod_new(const char *dirname
,
250 const char * const *config_paths
)
253 struct kmod_ctx
*ctx
;
256 ctx
= calloc(1, sizeof(struct kmod_ctx
));
261 ctx
->log_fn
= log_filep
;
262 ctx
->log_data
= stderr
;
263 ctx
->log_priority
= LOG_ERR
;
265 ctx
->dirname
= get_kernel_release(dirname
);
267 /* environment overwrites config */
268 env
= secure_getenv("KMOD_LOG");
270 kmod_set_log_priority(ctx
, log_priority(env
));
272 if (config_paths
== NULL
)
273 config_paths
= default_config_paths
;
274 err
= kmod_config_new(ctx
, &ctx
->config
, config_paths
);
276 ERR(ctx
, "could not create config\n");
280 ctx
->modules_by_name
= hash_new(KMOD_HASH_SIZE
, NULL
);
281 if (ctx
->modules_by_name
== NULL
) {
282 ERR(ctx
, "could not create by-name hash\n");
286 INFO(ctx
, "ctx %p created\n", ctx
);
287 DBG(ctx
, "log_priority=%d\n", ctx
->log_priority
);
292 free(ctx
->modules_by_name
);
300 * @ctx: kmod library context
302 * Take a reference of the kmod library context.
304 * Returns: the passed kmod library context
306 KMOD_EXPORT
struct kmod_ctx
*kmod_ref(struct kmod_ctx
*ctx
)
316 * @ctx: kmod library context
318 * Drop a reference of the kmod library context. If the refcount
319 * reaches zero, the resources of the context will be released.
321 * Returns: the passed kmod library context or NULL if it's freed
323 KMOD_EXPORT
struct kmod_ctx
*kmod_unref(struct kmod_ctx
*ctx
)
328 if (--ctx
->refcount
> 0)
331 INFO(ctx
, "context %p released\n", ctx
);
333 kmod_unload_resources(ctx
);
334 hash_free(ctx
->modules_by_name
);
337 kmod_config_free(ctx
->config
);
345 * @ctx: kmod library context
346 * @log_fn: function to be called for logging messages
347 * @data: data to pass to log function
349 * The built-in logging writes to stderr. It can be
350 * overridden by a custom function, to plug log messages
351 * into the user's logging functionality.
353 KMOD_EXPORT
void kmod_set_log_fn(struct kmod_ctx
*ctx
,
354 void (*log_fn
)(void *data
,
355 int priority
, const char *file
,
356 int line
, const char *fn
,
357 const char *format
, va_list args
),
362 ctx
->log_fn
= log_fn
;
363 ctx
->log_data
= (void *)data
;
364 INFO(ctx
, "custom logging function %p registered\n", log_fn
);
368 * kmod_get_log_priority:
369 * @ctx: kmod library context
371 * Returns: the current logging priority
373 KMOD_EXPORT
int kmod_get_log_priority(const struct kmod_ctx
*ctx
)
377 return ctx
->log_priority
;
381 * kmod_set_log_priority:
382 * @ctx: kmod library context
383 * @priority: the new logging priority
385 * Set the current logging priority. The value controls which messages
388 KMOD_EXPORT
void kmod_set_log_priority(struct kmod_ctx
*ctx
, int priority
)
392 ctx
->log_priority
= priority
;
395 struct kmod_module
*kmod_pool_get_module(struct kmod_ctx
*ctx
,
398 struct kmod_module
*mod
;
400 mod
= hash_find(ctx
->modules_by_name
, key
);
402 DBG(ctx
, "get module name='%s' found=%p\n", key
, mod
);
407 void kmod_pool_add_module(struct kmod_ctx
*ctx
, struct kmod_module
*mod
,
410 DBG(ctx
, "add %p key='%s'\n", mod
, key
);
412 hash_add(ctx
->modules_by_name
, key
, mod
);
415 void kmod_pool_del_module(struct kmod_ctx
*ctx
, struct kmod_module
*mod
,
418 DBG(ctx
, "del %p key='%s'\n", mod
, key
);
420 hash_del(ctx
->modules_by_name
, key
);
423 static int kmod_lookup_alias_from_alias_bin(struct kmod_ctx
*ctx
,
424 enum kmod_index index_number
,
426 struct kmod_list
**list
)
429 struct index_file
*idx
;
430 struct index_value
*realnames
, *realname
;
432 if (ctx
->indexes
[index_number
] != NULL
) {
433 DBG(ctx
, "use mmaped index '%s' for name=%s\n",
434 index_files
[index_number
].fn
, name
);
435 realnames
= index_mm_searchwild(ctx
->indexes
[index_number
],
440 snprintf(fn
, sizeof(fn
), "%s/%s.bin", ctx
->dirname
,
441 index_files
[index_number
].fn
);
443 DBG(ctx
, "file=%s name=%s\n", fn
, name
);
445 idx
= index_file_open(fn
);
449 realnames
= index_searchwild(idx
, name
);
450 index_file_close(idx
);
453 for (realname
= realnames
; realname
; realname
= realname
->next
) {
454 struct kmod_module
*mod
;
456 err
= kmod_module_new_from_alias(ctx
, name
, realname
->value
, &mod
);
458 ERR(ctx
, "Could not create module for alias=%s realname=%s: %s\n",
459 name
, realname
->value
, strerror(-err
));
463 *list
= kmod_list_append(*list
, mod
);
467 index_values_free(realnames
);
471 *list
= kmod_list_remove_n_latest(*list
, nmatch
);
472 index_values_free(realnames
);
477 int kmod_lookup_alias_from_symbols_file(struct kmod_ctx
*ctx
, const char *name
,
478 struct kmod_list
**list
)
480 if (!strstartswith(name
, "symbol:"))
483 return kmod_lookup_alias_from_alias_bin(ctx
, KMOD_INDEX_MODULES_SYMBOL
,
487 int kmod_lookup_alias_from_aliases_file(struct kmod_ctx
*ctx
, const char *name
,
488 struct kmod_list
**list
)
490 return kmod_lookup_alias_from_alias_bin(ctx
, KMOD_INDEX_MODULES_ALIAS
,
494 static char *lookup_builtin_file(struct kmod_ctx
*ctx
, const char *name
)
498 if (ctx
->indexes
[KMOD_INDEX_MODULES_BUILTIN
]) {
499 DBG(ctx
, "use mmaped index '%s' modname=%s\n",
500 index_files
[KMOD_INDEX_MODULES_BUILTIN
].fn
,
502 line
= index_mm_search(ctx
->indexes
[KMOD_INDEX_MODULES_BUILTIN
],
505 struct index_file
*idx
;
508 snprintf(fn
, sizeof(fn
), "%s/%s.bin", ctx
->dirname
,
509 index_files
[KMOD_INDEX_MODULES_BUILTIN
].fn
);
510 DBG(ctx
, "file=%s modname=%s\n", fn
, name
);
512 idx
= index_file_open(fn
);
514 DBG(ctx
, "could not open builtin file '%s'\n", fn
);
518 line
= index_search(idx
, name
);
519 index_file_close(idx
);
525 int kmod_lookup_alias_from_builtin_file(struct kmod_ctx
*ctx
, const char *name
,
526 struct kmod_list
**list
)
531 assert(*list
== NULL
);
533 line
= lookup_builtin_file(ctx
, name
);
535 struct kmod_module
*mod
;
537 err
= kmod_module_new_from_name(ctx
, name
, &mod
);
539 ERR(ctx
, "Could not create module from name %s: %s\n",
540 name
, strerror(-err
));
544 /* already mark it as builtin since it's being created from
546 kmod_module_set_builtin(mod
, true);
547 *list
= kmod_list_append(*list
, mod
);
557 bool kmod_lookup_alias_is_builtin(struct kmod_ctx
*ctx
, const char *name
)
559 _cleanup_free_
char *line
;
561 line
= lookup_builtin_file(ctx
, name
);
566 char *kmod_search_moddep(struct kmod_ctx
*ctx
, const char *name
)
568 struct index_file
*idx
;
572 if (ctx
->indexes
[KMOD_INDEX_MODULES_DEP
]) {
573 DBG(ctx
, "use mmaped index '%s' modname=%s\n",
574 index_files
[KMOD_INDEX_MODULES_DEP
].fn
, name
);
575 return index_mm_search(ctx
->indexes
[KMOD_INDEX_MODULES_DEP
],
579 snprintf(fn
, sizeof(fn
), "%s/%s.bin", ctx
->dirname
,
580 index_files
[KMOD_INDEX_MODULES_DEP
].fn
);
582 DBG(ctx
, "file=%s modname=%s\n", fn
, name
);
584 idx
= index_file_open(fn
);
586 DBG(ctx
, "could not open moddep file '%s'\n", fn
);
590 line
= index_search(idx
, name
);
591 index_file_close(idx
);
596 int kmod_lookup_alias_from_moddep_file(struct kmod_ctx
*ctx
, const char *name
,
597 struct kmod_list
**list
)
603 * Module names do not contain ':'. Return early if we know it will
606 if (strchr(name
, ':'))
609 line
= kmod_search_moddep(ctx
, name
);
611 struct kmod_module
*mod
;
613 n
= kmod_module_new_from_name(ctx
, name
, &mod
);
615 ERR(ctx
, "Could not create module from name %s: %s\n",
620 *list
= kmod_list_append(*list
, mod
);
621 kmod_module_parse_depline(mod
, line
);
630 int kmod_lookup_alias_from_config(struct kmod_ctx
*ctx
, const char *name
,
631 struct kmod_list
**list
)
633 struct kmod_config
*config
= ctx
->config
;
637 kmod_list_foreach(l
, config
->aliases
) {
638 const char *aliasname
= kmod_alias_get_name(l
);
639 const char *modname
= kmod_alias_get_modname(l
);
641 if (fnmatch(aliasname
, name
, 0) == 0) {
642 struct kmod_module
*mod
;
644 err
= kmod_module_new_from_alias(ctx
, aliasname
,
647 ERR(ctx
, "Could not create module for alias=%s modname=%s: %s\n",
648 name
, modname
, strerror(-err
));
652 *list
= kmod_list_append(*list
, mod
);
660 *list
= kmod_list_remove_n_latest(*list
, nmatch
);
664 int kmod_lookup_alias_from_commands(struct kmod_ctx
*ctx
, const char *name
,
665 struct kmod_list
**list
)
667 struct kmod_config
*config
= ctx
->config
;
668 struct kmod_list
*l
, *node
;
671 kmod_list_foreach(l
, config
->install_commands
) {
672 const char *modname
= kmod_command_get_modname(l
);
674 if (streq(modname
, name
)) {
675 const char *cmd
= kmod_command_get_command(l
);
676 struct kmod_module
*mod
;
678 err
= kmod_module_new_from_name(ctx
, modname
, &mod
);
680 ERR(ctx
, "Could not create module from name %s: %s\n",
681 modname
, strerror(-err
));
685 node
= kmod_list_append(*list
, mod
);
687 ERR(ctx
, "out of memory\n");
694 kmod_module_set_install_commands(mod
, cmd
);
697 * match only the first one, like modprobe from
698 * module-init-tools does
707 kmod_list_foreach(l
, config
->remove_commands
) {
708 const char *modname
= kmod_command_get_modname(l
);
710 if (streq(modname
, name
)) {
711 const char *cmd
= kmod_command_get_command(l
);
712 struct kmod_module
*mod
;
714 err
= kmod_module_new_from_name(ctx
, modname
, &mod
);
716 ERR(ctx
, "Could not create module from name %s: %s\n",
717 modname
, strerror(-err
));
721 node
= kmod_list_append(*list
, mod
);
723 ERR(ctx
, "out of memory\n");
730 kmod_module_set_remove_commands(mod
, cmd
);
733 * match only the first one, like modprobe from
734 * module-init-tools does
743 void kmod_set_modules_visited(struct kmod_ctx
*ctx
, bool visited
)
745 struct hash_iter iter
;
748 hash_iter_init(ctx
->modules_by_name
, &iter
);
749 while (hash_iter_next(&iter
, NULL
, &v
))
750 kmod_module_set_visited((struct kmod_module
*)v
, visited
);
753 void kmod_set_modules_required(struct kmod_ctx
*ctx
, bool required
)
755 struct hash_iter iter
;
758 hash_iter_init(ctx
->modules_by_name
, &iter
);
759 while (hash_iter_next(&iter
, NULL
, &v
))
760 kmod_module_set_required((struct kmod_module
*)v
, required
);
763 static bool is_cache_invalid(const char *path
, unsigned long long stamp
)
767 if (stat(path
, &st
) < 0)
770 if (stamp
!= stat_mstamp(&st
))
777 * kmod_validate_resources:
778 * @ctx: kmod library context
780 * Check if indexes and configuration files changed on disk and the current
781 * context is not valid anymore.
783 * Returns: KMOD_RESOURCES_OK if resources are still valid,
784 * KMOD_RESOURCES_MUST_RELOAD if it's sufficient to call
785 * kmod_unload_resources() and kmod_load_resources() or
786 * KMOD_RESOURCES_MUST_RECREATE if @ctx must be re-created.
788 KMOD_EXPORT
int kmod_validate_resources(struct kmod_ctx
*ctx
)
793 if (ctx
== NULL
|| ctx
->config
== NULL
)
794 return KMOD_RESOURCES_MUST_RECREATE
;
796 kmod_list_foreach(l
, ctx
->config
->paths
) {
797 struct kmod_config_path
*cf
= l
->data
;
799 if (is_cache_invalid(cf
->path
, cf
->stamp
))
800 return KMOD_RESOURCES_MUST_RECREATE
;
803 for (i
= 0; i
< _KMOD_INDEX_MODULES_SIZE
; i
++) {
806 if (ctx
->indexes
[i
] == NULL
)
809 snprintf(path
, sizeof(path
), "%s/%s.bin", ctx
->dirname
,
812 if (is_cache_invalid(path
, ctx
->indexes_stamp
[i
]))
813 return KMOD_RESOURCES_MUST_RELOAD
;
816 return KMOD_RESOURCES_OK
;
820 * kmod_load_resources:
821 * @ctx: kmod library context
823 * Load indexes and keep them open in @ctx. This way it's faster to lookup
824 * information within the indexes. If this function is not called before a
825 * search, the necessary index is always opened and closed.
827 * If user will do more than one or two lookups, insertions, deletions, most
828 * likely it's good to call this function first. Particularly in a daemon like
829 * udev that on bootup issues hundreds of calls to lookup the index, calling
830 * this function will speedup the searches.
832 * Returns: 0 on success or < 0 otherwise.
834 KMOD_EXPORT
int kmod_load_resources(struct kmod_ctx
*ctx
)
841 for (i
= 0; i
< _KMOD_INDEX_MODULES_SIZE
; i
++) {
844 if (ctx
->indexes
[i
] != NULL
) {
845 INFO(ctx
, "Index %s already loaded\n",
850 snprintf(path
, sizeof(path
), "%s/%s.bin", ctx
->dirname
,
852 ctx
->indexes
[i
] = index_mm_open(ctx
, path
,
853 &ctx
->indexes_stamp
[i
]);
854 if (ctx
->indexes
[i
] == NULL
)
861 kmod_unload_resources(ctx
);
866 * kmod_unload_resources:
867 * @ctx: kmod library context
869 * Unload all the indexes. This will free the resources to maintain the index
870 * open and all subsequent searches will need to open and close the index.
872 * User is free to call kmod_load_resources() and kmod_unload_resources() as
873 * many times as wanted during the lifecycle of @ctx. For example, if a daemon
874 * knows that when starting up it will lookup a lot of modules, it could call
875 * kmod_load_resources() and after the first burst of searches is gone, it
876 * could free the resources by calling kmod_unload_resources().
878 * Returns: 0 on success or < 0 otherwise.
880 KMOD_EXPORT
void kmod_unload_resources(struct kmod_ctx
*ctx
)
887 for (i
= 0; i
< _KMOD_INDEX_MODULES_SIZE
; i
++) {
888 if (ctx
->indexes
[i
] != NULL
) {
889 index_mm_close(ctx
->indexes
[i
]);
890 ctx
->indexes
[i
] = NULL
;
891 ctx
->indexes_stamp
[i
] = 0;
898 * @ctx: kmod library context
899 * @type: index to dump, valid indexes are
900 * KMOD_INDEX_MODULES_DEP: index of module dependencies;
901 * KMOD_INDEX_MODULES_ALIAS: index of module aliases;
902 * KMOD_INDEX_MODULES_SYMBOL: index of symbol aliases;
903 * KMOD_INDEX_MODULES_BUILTIN: index of builtin module.
904 * @fd: file descriptor to dump index to
906 * Dump index to file descriptor. Note that this function doesn't use stdio.h
907 * so call fflush() before calling this function to be sure data is written in
910 * Returns: 0 on success or < 0 otherwise.
912 KMOD_EXPORT
int kmod_dump_index(struct kmod_ctx
*ctx
, enum kmod_index type
,
918 if (type
< 0 || type
>= _KMOD_INDEX_MODULES_SIZE
)
921 if (ctx
->indexes
[type
] != NULL
) {
922 DBG(ctx
, "use mmaped index '%s'\n", index_files
[type
].fn
);
923 index_mm_dump(ctx
->indexes
[type
], fd
,
924 index_files
[type
].prefix
);
927 struct index_file
*idx
;
929 snprintf(fn
, sizeof(fn
), "%s/%s.bin", ctx
->dirname
,
930 index_files
[type
].fn
);
932 DBG(ctx
, "file=%s\n", fn
);
934 idx
= index_file_open(fn
);
938 index_dump(idx
, fd
, index_files
[type
].prefix
);
939 index_file_close(idx
);
945 const struct kmod_config
*kmod_get_config(const struct kmod_ctx
*ctx
)