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/*
Authors:
Pavel Březina <pbrezina@redhat.com>
Copyright (C) 2016 Red Hat
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <dlfcn.h>
#include "config.h"
#include "providers/data_provider/dp.h"
#include "providers/data_provider/dp_private.h"
#include "providers/backend.h"
#include "util/util.h"
/* There can be at most the same number of different modules loaded at
* one time as the maximum number of defined targets. */
#define DP_MAX_MODULES DP_TARGET_SENTINEL
#define DP_MODULE_PATH DATA_PROVIDER_PLUGINS_PATH "/libsss_%s.so"
#define DP_MODULE_INIT_FN "sssm_%s_init"
static errno_t dp_module_open_lib(struct dp_module *module)
{
char *libpath = NULL;
errno_t ret;
libpath = talloc_asprintf(module, DP_MODULE_PATH, module->name);
if (libpath == NULL) {
DEBUG(SSSDBG_CRIT_FAILURE, "talloc_asprintf() failed\n");
return ENOMEM;
}
DEBUG(SSSDBG_TRACE_LIBS, "Loading module [%s] with path [%s]\n",
module->name, libpath);
module->libhandle = dlopen(libpath, RTLD_NOW);
if (module->libhandle == NULL) {
DEBUG(SSSDBG_FATAL_FAILURE, "Unable to load module [%s] with path "
"[%s]: %s\n", module->name, libpath, dlerror());
ret = ELIBACC;
goto done;
}
ret = EOK;
done:
talloc_free(libpath);
return ret;
}
static errno_t dp_module_run_constructor(struct dp_module *module,
struct be_ctx *be_ctx,
struct data_provider *provider)
{
char *fn_name;
dp_module_init_fn fn;
errno_t ret;
fn_name = talloc_asprintf(module, DP_MODULE_INIT_FN, module->name);
if (fn_name == NULL) {
DEBUG(SSSDBG_CRIT_FAILURE, "talloc_asprintf() failed\n");
return ENOMEM;
}
fn = (dp_module_init_fn)dlsym(module->libhandle, fn_name);
if (fn != NULL) {
DEBUG(SSSDBG_TRACE_FUNC, "Executing module [%s] constructor.\n",
module->name);
ret = fn(module, be_ctx, provider, module->name, &module->module_data);
if (ret != EOK) {
DEBUG(SSSDBG_FATAL_FAILURE, "Module [%s] constructor failed "
"[%d]: %s\n", module->name, ret, sss_strerror(ret));
goto done;
}
} else {
DEBUG(SSSDBG_TRACE_FUNC, "No constructor found for module [%s].\n",
module->name);
module->module_data = NULL;
ret = EOK;
goto done;
}
ret = EOK;
done:
talloc_free(fn_name);
return ret;
}
static errno_t dp_module_find(struct dp_module **modules,
const char *name,
struct dp_module **_module,
unsigned int *_slot)
{
unsigned int slot;
for (slot = 0; modules[slot] != NULL; slot++) {
if (strcmp(modules[slot]->name, name) == 0) {
*_module = modules[slot];
*_slot = slot;
return EOK;
}
}
if (slot == DP_MAX_MODULES) {
/* This should not happen. */
DEBUG(SSSDBG_CRIT_FAILURE, "All module slots are taken.\n");
return ERR_INTERNAL;
}
*_module = NULL;
*_slot = slot;
return EOK;
}
static struct dp_module *dp_module_create(TALLOC_CTX *mem_ctx,
struct be_ctx *be_ctx,
struct data_provider *provider,
const char *name)
{
struct dp_module *module;
errno_t ret;
module = talloc_zero(mem_ctx, struct dp_module);
if (module == NULL) {
DEBUG(SSSDBG_CRIT_FAILURE, "talloc_zero() failed\n");
ret = ENOMEM;
goto done;
}
module->name = talloc_strdup(module, name);
if (module->name == NULL) {
DEBUG(SSSDBG_CRIT_FAILURE, "talloc_strdup() failed\n");
ret = ENOMEM;
goto done;
}
ret = dp_module_open_lib(module);
if (ret != EOK) {
goto done;
}
ret = dp_module_run_constructor(module, be_ctx, provider);
if (ret != EOK) {
goto done;
}
module->initialized = true;
ret = EOK;
done:
if (ret != EOK) {
talloc_free(module);
return NULL;
}
return module;
}
struct dp_module *dp_load_module(TALLOC_CTX *mem_ctx,
struct be_ctx *be_ctx,
struct data_provider *provider,
struct dp_module **modules,
const char *name)
{
struct dp_module *module;
unsigned int free_slot;
errno_t ret;
ret = dp_module_find(modules, name, &module, &free_slot);
if (ret != EOK) {
return NULL;
}
if (module != NULL) {
DEBUG(SSSDBG_TRACE_FUNC, "Module [%s] is already loaded.\n", name);
return module;
}
DEBUG(SSSDBG_TRACE_FUNC, "About to load module [%s].\n", name);
module = dp_module_create(mem_ctx, be_ctx, provider, name);
if (module == NULL) {
DEBUG(SSSDBG_CRIT_FAILURE, "Unable to create DP module.\n");
return NULL;
}
modules[free_slot] = module;
return module;
}
errno_t dp_init_modules(TALLOC_CTX *mem_ctx, struct dp_module ***_modules)
{
struct dp_module **modules;
modules = talloc_zero_array(mem_ctx, struct dp_module *,
DP_MAX_MODULES + 1);
if (modules == NULL) {
return ENOMEM;
}
*_modules = modules;
return EOK;
}
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