/* * libkmod - interface to kernel module operations * * Copyright (C) 2011-2013 ProFUSION embedded systems * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "libkmod.h" #include "libkmod-private.h" #include "libkmod-index.h" #define KMOD_HASH_SIZE (256) #define KMOD_LRU_MAX (128) #define _KMOD_INDEX_MODULES_SIZE KMOD_INDEX_MODULES_BUILTIN + 1 /** * SECTION:libkmod * @short_description: libkmod context * * The context contains the default values for the library user, * and is passed to all library operations. */ static struct _index_files { const char *fn; const char *prefix; } index_files[] = { [KMOD_INDEX_MODULES_DEP] = { .fn = "modules.dep", .prefix = "" }, [KMOD_INDEX_MODULES_ALIAS] = { .fn = "modules.alias", .prefix = "alias " }, [KMOD_INDEX_MODULES_SYMBOL] = { .fn = "modules.symbols", .prefix = "alias "}, [KMOD_INDEX_MODULES_BUILTIN] = { .fn = "modules.builtin", .prefix = ""}, }; static const char *default_config_paths[] = { SYSCONFDIR "/modprobe.d", "/run/modprobe.d", "/lib/modprobe.d", NULL }; /** * kmod_ctx: * * Opaque object representing the library context. */ struct kmod_ctx { int refcount; int log_priority; void (*log_fn)(void *data, int priority, const char *file, int line, const char *fn, const char *format, va_list args); void *log_data; const void *userdata; char *dirname; struct kmod_config *config; struct hash *modules_by_name; struct index_mm *indexes[_KMOD_INDEX_MODULES_SIZE]; unsigned long long indexes_stamp[_KMOD_INDEX_MODULES_SIZE]; }; void kmod_log(const struct kmod_ctx *ctx, int priority, const char *file, int line, const char *fn, const char *format, ...) { va_list args; if (ctx->log_fn == NULL) return; va_start(args, format); ctx->log_fn(ctx->log_data, priority, file, line, fn, format, args); va_end(args); } _printf_format_(6, 0) static void log_filep(void *data, int priority, const char *file, int line, const char *fn, const char *format, va_list args) { FILE *fp = data; #ifdef ENABLE_DEBUG char buf[16]; const char *priname; switch (priority) { case LOG_EMERG: priname = "EMERGENCY"; break; case LOG_ALERT: priname = "ALERT"; break; case LOG_CRIT: priname = "CRITICAL"; break; case LOG_ERR: priname = "ERROR"; break; case LOG_WARNING: priname = "WARNING"; break; case LOG_NOTICE: priname = "NOTICE"; break; case LOG_INFO: priname = "INFO"; break; case LOG_DEBUG: priname = "DEBUG"; break; default: snprintf(buf, sizeof(buf), "L:%d", priority); priname = buf; } fprintf(fp, "libkmod: %s %s:%d %s: ", priname, file, line, fn); #else fprintf(fp, "libkmod: %s: ", fn); #endif vfprintf(fp, format, args); } const char *kmod_get_dirname(const struct kmod_ctx *ctx) { return ctx->dirname; } /** * kmod_get_userdata: * @ctx: kmod library context * * Retrieve stored data pointer from library context. This might be useful * to access from callbacks. * * Returns: stored userdata */ KMOD_EXPORT void *kmod_get_userdata(const struct kmod_ctx *ctx) { if (ctx == NULL) return NULL; return (void *)ctx->userdata; } /** * kmod_set_userdata: * @ctx: kmod library context * @userdata: data pointer * * Store custom @userdata in the library context. */ KMOD_EXPORT void kmod_set_userdata(struct kmod_ctx *ctx, const void *userdata) { if (ctx == NULL) return; ctx->userdata = userdata; } static int log_priority(const char *priority) { char *endptr; int prio; prio = strtol(priority, &endptr, 10); if (endptr[0] == '\0' || isspace(endptr[0])) return prio; if (strncmp(priority, "err", 3) == 0) return LOG_ERR; if (strncmp(priority, "info", 4) == 0) return LOG_INFO; if (strncmp(priority, "debug", 5) == 0) return LOG_DEBUG; return 0; } static const char *dirname_default_prefix = "/lib/modules"; static char *get_kernel_release(const char *dirname) { struct utsname u; char *p; if (dirname != NULL) return path_make_absolute_cwd(dirname); if (uname(&u) < 0) return NULL; if (asprintf(&p, "%s/%s", dirname_default_prefix, u.release) < 0) return NULL; return p; } /** * kmod_new: * @dirname: what to consider as linux module's directory, if NULL * defaults to /lib/modules/`uname -r`. If it's relative, * it's treated as relative to current the current working * directory. Otherwise, give an absolute dirname. * @config_paths: ordered array of paths (directories or files) where * to load from user-defined configuration parameters such as * alias, blacklists, commands (install, remove). If * NULL defaults to /run/modprobe.d, /etc/modprobe.d and * /lib/modprobe.d. Give an empty vector if configuration should * not be read. This array must be null terminated. * * Create kmod library context. This reads the kmod configuration * and fills in the default values. * * The initial refcount is 1, and needs to be decremented to * release the resources of the kmod library context. * * Returns: a new kmod library context */ KMOD_EXPORT struct kmod_ctx *kmod_new(const char *dirname, const char * const *config_paths) { const char *env; struct kmod_ctx *ctx; int err; ctx = calloc(1, sizeof(struct kmod_ctx)); if (!ctx) return NULL; ctx->refcount = 1; ctx->log_fn = log_filep; ctx->log_data = stderr; ctx->log_priority = LOG_ERR; ctx->dirname = get_kernel_release(dirname); /* environment overwrites config */ env = secure_getenv("KMOD_LOG"); if (env != NULL) kmod_set_log_priority(ctx, log_priority(env)); if (config_paths == NULL) config_paths = default_config_paths; err = kmod_config_new(ctx, &ctx->config, config_paths); if (err < 0) { ERR(ctx, "could not create config\n"); goto fail; } ctx->modules_by_name = hash_new(KMOD_HASH_SIZE, NULL); if (ctx->modules_by_name == NULL) { ERR(ctx, "could not create by-name hash\n"); goto fail; } INFO(ctx, "ctx %p created\n", ctx); DBG(ctx, "log_priority=%d\n", ctx->log_priority); return ctx; fail: free(ctx->modules_by_name); free(ctx->dirname); free(ctx); return NULL; } /** * kmod_ref: * @ctx: kmod library context * * Take a reference of the kmod library context. * * Returns: the passed kmod library context */ KMOD_EXPORT struct kmod_ctx *kmod_ref(struct kmod_ctx *ctx) { if (ctx == NULL) return NULL; ctx->refcount++; return ctx; } /** * kmod_unref: * @ctx: kmod library context * * Drop a reference of the kmod library context. If the refcount * reaches zero, the resources of the context will be released. */ KMOD_EXPORT struct kmod_ctx *kmod_unref(struct kmod_ctx *ctx) { if (ctx == NULL) return NULL; if (--ctx->refcount > 0) return ctx; INFO(ctx, "context %p released\n", ctx); kmod_unload_resources(ctx); hash_free(ctx->modules_by_name); free(ctx->dirname); if (ctx->config) kmod_config_free(ctx->config); free(ctx); return NULL; } /** * kmod_set_log_fn: * @ctx: kmod library context * @log_fn: function to be called for logging messages * @data: data to pass to log function * * The built-in logging writes to stderr. It can be * overridden by a custom function, to plug log messages * into the user's logging functionality. */ KMOD_EXPORT void kmod_set_log_fn(struct kmod_ctx *ctx, void (*log_fn)(void *data, int priority, const char *file, int line, const char *fn, const char *format, va_list args), const void *data) { if (ctx == NULL) return; ctx->log_fn = log_fn; ctx->log_data = (void *)data; INFO(ctx, "custom logging function %p registered\n", log_fn); } /** * kmod_get_log_priority: * @ctx: kmod library context * * Returns: the current logging priority */ KMOD_EXPORT int kmod_get_log_priority(const struct kmod_ctx *ctx) { if (ctx == NULL) return -1; return ctx->log_priority; } /** * kmod_set_log_priority: * @ctx: kmod library context * @priority: the new logging priority * * Set the current logging priority. The value controls which messages * are logged. */ KMOD_EXPORT void kmod_set_log_priority(struct kmod_ctx *ctx, int priority) { if (ctx == NULL) return; ctx->log_priority = priority; } struct kmod_module *kmod_pool_get_module(struct kmod_ctx *ctx, const char *key) { struct kmod_module *mod; mod = hash_find(ctx->modules_by_name, key); DBG(ctx, "get module name='%s' found=%p\n", key, mod); return mod; } void kmod_pool_add_module(struct kmod_ctx *ctx, struct kmod_module *mod, const char *key) { DBG(ctx, "add %p key='%s'\n", mod, key); hash_add(ctx->modules_by_name, key, mod); } void kmod_pool_del_module(struct kmod_ctx *ctx, struct kmod_module *mod, const char *key) { DBG(ctx, "del %p key='%s'\n", mod, key); hash_del(ctx->modules_by_name, key); } static int kmod_lookup_alias_from_alias_bin(struct kmod_ctx *ctx, enum kmod_index index_number, const char *name, struct kmod_list **list) { int err, nmatch = 0; struct index_file *idx; struct index_value *realnames, *realname; if (ctx->indexes[index_number] != NULL) { DBG(ctx, "use mmaped index '%s' for name=%s\n", index_files[index_number].fn, name); realnames = index_mm_searchwild(ctx->indexes[index_number], name); } else { char fn[PATH_MAX]; snprintf(fn, sizeof(fn), "%s/%s.bin", ctx->dirname, index_files[index_number].fn); DBG(ctx, "file=%s name=%s\n", fn, name); idx = index_file_open(fn); if (idx == NULL) return -ENOSYS; realnames = index_searchwild(idx, name); index_file_close(idx); } for (realname = realnames; realname; realname = realname->next) { struct kmod_module *mod; err = kmod_module_new_from_alias(ctx, name, realname->value, &mod); if (err < 0) { ERR(ctx, "Could not create module for alias=%s realname=%s: %s\n", name, realname->value, strerror(-err)); goto fail; } *list = kmod_list_append(*list, mod); nmatch++; } index_values_free(realnames); return nmatch; fail: *list = kmod_list_remove_n_latest(*list, nmatch); return err; } int kmod_lookup_alias_from_symbols_file(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) { if (!strstartswith(name, "symbol:")) return 0; return kmod_lookup_alias_from_alias_bin(ctx, KMOD_INDEX_MODULES_SYMBOL, name, list); } int kmod_lookup_alias_from_aliases_file(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) { return kmod_lookup_alias_from_alias_bin(ctx, KMOD_INDEX_MODULES_ALIAS, name, list); } int kmod_lookup_alias_from_builtin_file(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) { char *line = NULL; int err = 0; assert(*list == NULL); if (ctx->indexes[KMOD_INDEX_MODULES_BUILTIN]) { DBG(ctx, "use mmaped index '%s' modname=%s\n", index_files[KMOD_INDEX_MODULES_BUILTIN].fn, name); line = index_mm_search(ctx->indexes[KMOD_INDEX_MODULES_BUILTIN], name); } else { struct index_file *idx; char fn[PATH_MAX]; snprintf(fn, sizeof(fn), "%s/%s.bin", ctx->dirname, index_files[KMOD_INDEX_MODULES_BUILTIN].fn); DBG(ctx, "file=%s modname=%s\n", fn, name); idx = index_file_open(fn); if (idx == NULL) { DBG(ctx, "could not open builtin file '%s'\n", fn); goto finish; } line = index_search(idx, name); index_file_close(idx); } if (line != NULL) { struct kmod_module *mod; err = kmod_module_new_from_name(ctx, name, &mod); if (err < 0) { ERR(ctx, "Could not create module from name %s: %s\n", name, strerror(-err)); goto finish; } kmod_module_set_builtin(mod, true); *list = kmod_list_append(*list, mod); if (*list == NULL) err = -ENOMEM; } finish: free(line); return err; } char *kmod_search_moddep(struct kmod_ctx *ctx, const char *name) { struct index_file *idx; char fn[PATH_MAX]; char *line; if (ctx->indexes[KMOD_INDEX_MODULES_DEP]) { DBG(ctx, "use mmaped index '%s' modname=%s\n", index_files[KMOD_INDEX_MODULES_DEP].fn, name); return index_mm_search(ctx->indexes[KMOD_INDEX_MODULES_DEP], name); } snprintf(fn, sizeof(fn), "%s/%s.bin", ctx->dirname, index_files[KMOD_INDEX_MODULES_DEP].fn); DBG(ctx, "file=%s modname=%s\n", fn, name); idx = index_file_open(fn); if (idx == NULL) { DBG(ctx, "could not open moddep file '%s'\n", fn); return NULL; } line = index_search(idx, name); index_file_close(idx); return line; } int kmod_lookup_alias_from_moddep_file(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) { char *line; int n = 0; /* * Module names do not contain ':'. Return early if we know it will * not be found. */ if (strchr(name, ':')) return 0; line = kmod_search_moddep(ctx, name); if (line != NULL) { struct kmod_module *mod; n = kmod_module_new_from_name(ctx, name, &mod); if (n < 0) { ERR(ctx, "Could not create module from name %s: %s\n", name, strerror(-n)); goto finish; } *list = kmod_list_append(*list, mod); kmod_module_parse_depline(mod, line); } finish: free(line); return n; } int kmod_lookup_alias_from_config(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) { struct kmod_config *config = ctx->config; struct kmod_list *l; int err, nmatch = 0; kmod_list_foreach(l, config->aliases) { const char *aliasname = kmod_alias_get_name(l); const char *modname = kmod_alias_get_modname(l); if (fnmatch(aliasname, name, 0) == 0) { struct kmod_module *mod; err = kmod_module_new_from_alias(ctx, aliasname, modname, &mod); if (err < 0) { ERR(ctx, "Could not create module for alias=%s modname=%s: %s\n", name, modname, strerror(-err)); goto fail; } *list = kmod_list_append(*list, mod); nmatch++; } } return nmatch; fail: *list = kmod_list_remove_n_latest(*list, nmatch); return err; } int kmod_lookup_alias_from_commands(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) { struct kmod_config *config = ctx->config; struct kmod_list *l, *node; int err, nmatch = 0; kmod_list_foreach(l, config->install_commands) { const char *modname = kmod_command_get_modname(l); if (streq(modname, name)) { const char *cmd = kmod_command_get_command(l); struct kmod_module *mod; err = kmod_module_new_from_name(ctx, modname, &mod); if (err < 0) { ERR(ctx, "Could not create module from name %s: %s\n", modname, strerror(-err)); return err; } node = kmod_list_append(*list, mod); if (node == NULL) { ERR(ctx, "out of memory\n"); return -ENOMEM; } *list = node; nmatch = 1; kmod_module_set_install_commands(mod, cmd); /* * match only the first one, like modprobe from * module-init-tools does */ break; } } if (nmatch) return nmatch; kmod_list_foreach(l, config->remove_commands) { const char *modname = kmod_command_get_modname(l); if (streq(modname, name)) { const char *cmd = kmod_command_get_command(l); struct kmod_module *mod; err = kmod_module_new_from_name(ctx, modname, &mod); if (err < 0) { ERR(ctx, "Could not create module from name %s: %s\n", modname, strerror(-err)); return err; } node = kmod_list_append(*list, mod); if (node == NULL) { ERR(ctx, "out of memory\n"); return -ENOMEM; } *list = node; nmatch = 1; kmod_module_set_remove_commands(mod, cmd); /* * match only the first one, like modprobe from * module-init-tools does */ break; } } return nmatch; } void kmod_set_modules_visited(struct kmod_ctx *ctx, bool visited) { struct hash_iter iter; const void *v; hash_iter_init(ctx->modules_by_name, &iter); while (hash_iter_next(&iter, NULL, &v)) kmod_module_set_visited((struct kmod_module *)v, visited); } static bool is_cache_invalid(const char *path, unsigned long long stamp) { struct stat st; if (stat(path, &st) < 0) return true; if (stamp != stat_mstamp(&st)) return true; return false; } /** * kmod_validate_resources: * @ctx: kmod library context * * Check if indexes and configuration files changed on disk and the current * context is not valid anymore. * * Returns: KMOD_RESOURCES_OK if resources are still valid, * KMOD_RESOURCES_MUST_RELOAD if it's sufficient to call * kmod_unload_resources() and kmod_load_resources() or * KMOD_RESOURCES_MUST_RECREATE if @ctx must be re-created. */ KMOD_EXPORT int kmod_validate_resources(struct kmod_ctx *ctx) { struct kmod_list *l; size_t i; if (ctx == NULL || ctx->config == NULL) return KMOD_RESOURCES_MUST_RECREATE; kmod_list_foreach(l, ctx->config->paths) { struct kmod_config_path *cf = l->data; if (is_cache_invalid(cf->path, cf->stamp)) return KMOD_RESOURCES_MUST_RECREATE; } for (i = 0; i < _KMOD_INDEX_MODULES_SIZE; i++) { char path[PATH_MAX]; if (ctx->indexes[i] == NULL) continue; snprintf(path, sizeof(path), "%s/%s.bin", ctx->dirname, index_files[i].fn); if (is_cache_invalid(path, ctx->indexes_stamp[i])) return KMOD_RESOURCES_MUST_RELOAD; } return KMOD_RESOURCES_OK; } /** * kmod_load_resources: * @ctx: kmod library context * * Load indexes and keep them open in @ctx. This way it's faster to lookup * information within the indexes. If this function is not called before a * search, the necessary index is always opened and closed. * * If user will do more than one or two lookups, insertions, deletions, most * likely it's good to call this function first. Particularly in a daemon like * udev that on bootup issues hundreds of calls to lookup the index, calling * this function will speedup the searches. * * Returns: 0 on success or < 0 otherwise. */ KMOD_EXPORT int kmod_load_resources(struct kmod_ctx *ctx) { size_t i; if (ctx == NULL) return -ENOENT; for (i = 0; i < _KMOD_INDEX_MODULES_SIZE; i++) { char path[PATH_MAX]; if (ctx->indexes[i] != NULL) { INFO(ctx, "Index %s already loaded\n", index_files[i].fn); continue; } snprintf(path, sizeof(path), "%s/%s.bin", ctx->dirname, index_files[i].fn); ctx->indexes[i] = index_mm_open(ctx, path, &ctx->indexes_stamp[i]); if (ctx->indexes[i] == NULL) goto fail; } return 0; fail: kmod_unload_resources(ctx); return -ENOMEM; } /** * kmod_unload_resources: * @ctx: kmod library context * * Unload all the indexes. This will free the resources to maintain the index * open and all subsequent searches will need to open and close the index. * * User is free to call kmod_load_resources() and kmod_unload_resources() as * many times as wanted during the lifecycle of @ctx. For example, if a daemon * knows that when starting up it will lookup a lot of modules, it could call * kmod_load_resources() and after the first burst of searches is gone, it * could free the resources by calling kmod_unload_resources(). * * Returns: 0 on success or < 0 otherwise. */ KMOD_EXPORT void kmod_unload_resources(struct kmod_ctx *ctx) { size_t i; if (ctx == NULL) return; for (i = 0; i < _KMOD_INDEX_MODULES_SIZE; i++) { if (ctx->indexes[i] != NULL) { index_mm_close(ctx->indexes[i]); ctx->indexes[i] = NULL; ctx->indexes_stamp[i] = 0; } } } /** * kmod_dump_index: * @ctx: kmod library context * @type: index to dump * @fd: file descriptor to dump index to * * Dump index to file descriptor. Note that this function doesn't use stdio.h * so call fflush() before calling this function to be sure data is written in * order. * * Returns: 0 on success or < 0 otherwise. */ KMOD_EXPORT int kmod_dump_index(struct kmod_ctx *ctx, enum kmod_index type, int fd) { if (ctx == NULL) return -ENOSYS; if (type < 0 || type >= _KMOD_INDEX_MODULES_SIZE) return -ENOENT; if (ctx->indexes[type] != NULL) { DBG(ctx, "use mmaped index '%s'\n", index_files[type].fn); index_mm_dump(ctx->indexes[type], fd, index_files[type].prefix); } else { char fn[PATH_MAX]; struct index_file *idx; snprintf(fn, sizeof(fn), "%s/%s.bin", ctx->dirname, index_files[type].fn); DBG(ctx, "file=%s\n", fn); idx = index_file_open(fn); if (idx == NULL) return -ENOSYS; index_dump(idx, fd, index_files[type].prefix); index_file_close(idx); } return 0; } const struct kmod_config *kmod_get_config(const struct kmod_ctx *ctx) { return ctx->config; }