kmod/libkmod/libkmod.c
Lucas De Marchi 719282889a Revert "libkmod: make sure to export kmod_log"
This reverts commit 88a170dbd6.

There's no reason for users of the API to call this method, it's just
wrong to export it.

The bug that this patch fixed needs to be fixed another way, not
exporting this function.
2012-05-10 20:58:46 -03:00

928 lines
21 KiB
C

/*
* 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 <assert.h>
#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_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",
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);
}
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_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;
}