res/ari/config.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * David M. Lee, II <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Config framework stuffz for ARI.
 * \author David M. Lee, II <[email protected]>
 */

#include "asterisk.h"

#include "asterisk/config_options.h"
#include "asterisk/http_websocket.h"
#include "asterisk/app.h"
#include "asterisk/channel.h"
#include "internal.h"

/*! \brief Locking container for safe configuration access. */
static AO2_GLOBAL_OBJ_STATIC(confs);

/*! \brief Mapping of the ARI conf struct's globals to the
 * general context in the config file. */
static struct aco_type general_option = {
 .type = ACO_GLOBAL,
 .name = "general",
 .item_offset = offsetof(struct ast_ari_conf, general),
 .category = "general",
 .category_match = ACO_WHITELIST_EXACT,
};

static struct aco_type *general_options[] = ACO_TYPES(&general_option);

/*! \brief Encoding format handler converts from boolean to enum. */
static int encoding_format_handler(const struct aco_option *opt,
 struct ast_variable *var, void *obj)
{
 struct ast_ari_conf_general *general = obj;

 if (!strcasecmp(var->name, "pretty")) {
 general->format = ast_true(var->value) ?
 AST_JSON_PRETTY : AST_JSON_COMPACT;
 } else {
 return -1;
 }

 return 0;
}

/*! \brief Parses the ast_ari_password_format enum from a config file */
static int password_format_handler(const struct aco_option *opt,
 struct ast_variable *var, void *obj)
{
 struct ast_ari_conf_user *user = obj;

 if (strcasecmp(var->value, "plain") == 0) {
 user->password_format = ARI_PASSWORD_FORMAT_PLAIN;
 } else if (strcasecmp(var->value, "crypt") == 0) {
 user->password_format = ARI_PASSWORD_FORMAT_CRYPT;
 } else {
 return -1;
 }

 return 0;
}

/*! \brief Destructor for \ref ast_ari_conf_user */
static void user_dtor(void *obj)
{
 struct ast_ari_conf_user *user = obj;
 ast_debug(3, "Disposing of user %s\n", user->username);
 ast_free(user->username);
}

/*! \brief Allocate an \ref ast_ari_conf_user for config parsing */
static void *user_alloc(const char *cat)
{
 RAII_VAR(struct ast_ari_conf_user *, user, NULL, ao2_cleanup);

 if (!cat) {
 return NULL;
 }

 ast_debug(3, "Allocating user %s\n", cat);

 user = ao2_alloc_options(sizeof(*user), user_dtor,
 AO2_ALLOC_OPT_LOCK_NOLOCK);
 if (!user) {
 return NULL;
 }

 user->username = ast_strdup(cat);
 if (!user->username) {
 return NULL;
 }

 ao2_ref(user, +1);
 return user;
}

/*! \brief Sorting function for use with red/black tree */
static int user_sort_cmp(const void *obj_left, const void *obj_right, int flags)
{
 const struct ast_ari_conf_user *user_left = obj_left;
 const struct ast_ari_conf_user *user_right = obj_right;
 const char *key_right = obj_right;
 int cmp;

 switch (flags & OBJ_SEARCH_MASK) {
 case OBJ_SEARCH_OBJECT:
 key_right = user_right->username;
 /* Fall through */
 case OBJ_SEARCH_KEY:
 cmp = strcasecmp(user_left->username, key_right);
 break;
 case OBJ_SEARCH_PARTIAL_KEY:
 /*
 * We could also use a partial key struct containing a length
 * so strlen() does not get called for every comparison instead.
 */
 cmp = strncasecmp(user_left->username, key_right, strlen(key_right));
 break;
 default:
 /* Sort can only work on something with a full or partial key. */
 ast_assert(0);
 cmp = 0;
 break;
 }
 return cmp;
}

/*! \brief \ref aco_type item_find function */
static void *user_find(struct ao2_container *tmp_container, const char *cat)
{
 if (!cat) {
 return NULL;
 }

 return ao2_find(tmp_container, cat, OBJ_SEARCH_KEY);
}

static struct aco_type user_option = {
 .type = ACO_ITEM,
 .name = "user",
 .category_match = ACO_BLACKLIST_EXACT,
 .category = "general",
 .matchfield = "type",
 .matchvalue = "user",
 .item_alloc = user_alloc,
 .item_find = user_find,
 .item_offset = offsetof(struct ast_ari_conf, users),
};

static struct aco_type *global_user[] = ACO_TYPES(&user_option);

static void conf_general_dtor(void *obj)
{
 struct ast_ari_conf_general *general = obj;

 ast_string_field_free_memory(general);
}

/*! \brief \ref ast_ari_conf destructor. */
static void conf_destructor(void *obj)
{
 struct ast_ari_conf *cfg = obj;

 ao2_cleanup(cfg->general);
 ao2_cleanup(cfg->users);
}

/*! \brief Allocate an \ref ast_ari_conf for config parsing */
static void *conf_alloc(void)
{
 struct ast_ari_conf *cfg;

 cfg = ao2_alloc_options(sizeof(*cfg), conf_destructor,
 AO2_ALLOC_OPT_LOCK_NOLOCK);
 if (!cfg) {
 return NULL;
 }

 cfg->general = ao2_alloc_options(sizeof(*cfg->general), conf_general_dtor,
 AO2_ALLOC_OPT_LOCK_NOLOCK);

 cfg->users = ao2_container_alloc_rbtree(AO2_ALLOC_OPT_LOCK_NOLOCK,
 AO2_CONTAINER_ALLOC_OPT_DUPS_REPLACE, user_sort_cmp, NULL);

 if (!cfg->users
 || !cfg->general
 || ast_string_field_init(cfg->general, 64)
 || aco_set_defaults(&general_option, "general", cfg->general)) {
 ao2_ref(cfg, -1);
 return NULL;
 }

 return cfg;
}

#define CONF_FILENAME "ari.conf"

/*! \brief The conf file that's processed for the module. */
static struct aco_file conf_file = {
 /*! The config file name. */
 .filename = CONF_FILENAME,
 /*! The mapping object types to be processed. */
 .types = ACO_TYPES(&general_option, &user_option),
};

CONFIG_INFO_STANDARD(cfg_info, confs, conf_alloc,
 .files = ACO_FILES(&conf_file));

struct ast_ari_conf *ast_ari_config_get(void)
{
 struct ast_ari_conf *res = ao2_global_obj_ref(confs);
 if (!res) {
 ast_log(LOG_ERROR,
 "Error obtaining config from " CONF_FILENAME "\n");
 }
 return res;
}

struct ast_ari_conf_user *ast_ari_config_validate_user(const char *username,
 const char *password)
{
 RAII_VAR(struct ast_ari_conf *, conf, NULL, ao2_cleanup);
 RAII_VAR(struct ast_ari_conf_user *, user, NULL, ao2_cleanup);
 int is_valid = 0;

 conf = ast_ari_config_get();
 if (!conf) {
 return NULL;
 }

 user = ao2_find(conf->users, username, OBJ_SEARCH_KEY);
 if (!user) {
 return NULL;
 }

 if (ast_strlen_zero(user->password)) {
 ast_log(LOG_WARNING,
 "User '%s' missing password; authentication failed\n",
 user->username);
 return NULL;
 }

 switch (user->password_format) {
 case ARI_PASSWORD_FORMAT_PLAIN:
 is_valid = strcmp(password, user->password) == 0;
 break;
 case ARI_PASSWORD_FORMAT_CRYPT:
 is_valid = ast_crypt_validate(password, user->password);
 break;
 }

 if (!is_valid) {
 return NULL;
 }

 ao2_ref(user, +1);
 return user;
}

/*! \brief Callback to validate a user object */
static int validate_user_cb(void *obj, void *arg, int flags)
{
 struct ast_ari_conf_user *user = obj;

 if (ast_strlen_zero(user->password)) {
 ast_log(LOG_WARNING, "User '%s' missing password\n",
 user->username);
 }

 return 0;
}

/*! \brief Load (or reload) configuration. */
static int process_config(int reload)
{
 RAII_VAR(struct ast_ari_conf *, conf, NULL, ao2_cleanup);

 switch (aco_process_config(&cfg_info, reload)) {
 case ACO_PROCESS_ERROR:
 return -1;
 case ACO_PROCESS_OK:
 case ACO_PROCESS_UNCHANGED:
 break;
 }

 conf = ast_ari_config_get();
 if (!conf) {
 ast_assert(0); /* We just configured; it should be there */
 return -1;
 }

 if (conf->general->enabled) {
 if (ao2_container_count(conf->users) == 0) {
 ast_log(LOG_ERROR, "No configured users for ARI\n");
 } else {
 ao2_callback(conf->users, OBJ_NODATA, validate_user_cb, NULL);
 }
 }

 return 0;
}

#define MAX_VARS 128

static int channelvars_handler(const struct aco_option *opt, struct ast_variable *var, void *obj)
{
 char *parse = NULL;
 AST_DECLARE_APP_ARGS(args,
 AST_APP_ARG(vars)[MAX_VARS];
 );

 parse = ast_strdupa(var->value);
 AST_STANDARD_APP_ARGS(args, parse);

 ast_channel_set_ari_vars(args.argc, args.vars);
 return 0;
}

int ast_ari_config_init(void)
{
 if (aco_info_init(&cfg_info)) {
 aco_info_destroy(&cfg_info);
 return -1;
 }

 /* ARI general category options */
 aco_option_register(&cfg_info, "enabled", ACO_EXACT, general_options,
 "yes", OPT_BOOL_T, 1,
 FLDSET(struct ast_ari_conf_general, enabled));
 aco_option_register_custom(&cfg_info, "pretty", ACO_EXACT,
 general_options, "no", encoding_format_handler, 0);
 aco_option_register(&cfg_info, "auth_realm", ACO_EXACT, general_options,
 "Asterisk REST Interface", OPT_CHAR_ARRAY_T, 0,
 FLDSET(struct ast_ari_conf_general, auth_realm),
 ARI_AUTH_REALM_LEN);
 aco_option_register(&cfg_info, "allowed_origins", ACO_EXACT, general_options,
 "", OPT_STRINGFIELD_T, 0,
 STRFLDSET(struct ast_ari_conf_general, allowed_origins));
 aco_option_register(&cfg_info, "websocket_write_timeout", ACO_EXACT, general_options,
 AST_DEFAULT_WEBSOCKET_WRITE_TIMEOUT_STR, OPT_INT_T, PARSE_IN_RANGE,
 FLDSET(struct ast_ari_conf_general, write_timeout), 1, INT_MAX);
 aco_option_register_custom(&cfg_info, "channelvars", ACO_EXACT, general_options,
 "", channelvars_handler, 0);

 /* ARI type=user category options */
 aco_option_register(&cfg_info, "type", ACO_EXACT, global_user, NULL,
 OPT_NOOP_T, 0, 0);
 aco_option_register(&cfg_info, "read_only", ACO_EXACT, global_user,
 "no", OPT_BOOL_T, 1,
 FLDSET(struct ast_ari_conf_user, read_only));
 aco_option_register(&cfg_info, "password", ACO_EXACT, global_user,
 "", OPT_CHAR_ARRAY_T, 0,
 FLDSET(struct ast_ari_conf_user, password), ARI_PASSWORD_LEN);
 aco_option_register_custom(&cfg_info, "password_format", ACO_EXACT,
 global_user, "plain", password_format_handler, 0);

 return process_config(0);
}

int ast_ari_config_reload(void)
{
 return process_config(1);
}

void ast_ari_config_destroy(void)
{
 aco_info_destroy(&cfg_info);
 ao2_global_obj_release(confs);
}