blob: 4990d3e5faf7d57f6a275271caf5fe5acce89f82 [file] [log] [blame]
/*
* libkmod - interface to kernel module operations
*
* Copyright (C) 2011-2012 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 <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdarg.h>
#include <limits.h>
#include <unistd.h>
#include <errno.h>
#include <fnmatch.h>
#include <string.h>
#include <ctype.h>
#include <sys/utsname.h>
#include <sys/stat.h>
#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_SYMBOL + 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 "},
};
static const char *default_config_paths[] = {
"/run/modprobe.d",
SYSCONFDIR "/modprobe.d",
ROOTPREFIX "/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);
}
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 = ROOTPREFIX "/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 $rootprefix/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
* $rootprefix/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 = 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);
}
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) {
ERR(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, true,
&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_list *kmod_get_blacklists(const struct kmod_ctx *ctx)
{
return ctx->config->blacklists;
}
const struct kmod_list *kmod_get_options(const struct kmod_ctx *ctx)
{
return ctx->config->options;
}
const struct kmod_list *kmod_get_install_commands(const struct kmod_ctx *ctx)
{
return ctx->config->install_commands;
}
const struct kmod_list *kmod_get_remove_commands(const struct kmod_ctx *ctx)
{
return ctx->config->remove_commands;
}
const struct kmod_list *kmod_get_softdeps(const struct kmod_ctx *ctx)
{
return ctx->config->softdeps;
}
const struct kmod_list *kmod_get_aliases(const struct kmod_ctx *ctx)
{
return ctx->config->aliases;
}