config_system.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * Mark Michelson <mmichelson@digium.com>
 *
 * 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.
 */
 
#include "asterisk.h"
 
#include <pjsip.h>
#include <pjlib.h>
 
#include "asterisk/res_pjsip.h"
#include "asterisk/sorcery.h"
#include "include/res_pjsip_private.h"
#include "asterisk/threadpool.h"
#include "asterisk/dns.h"
#include "asterisk/res_pjsip_cli.h"
 
#define TIMER_T1_MIN 100
#define DEFAULT_TIMER_T1 500
#define DEFAULT_TIMER_B 32000
 
struct system_config {
    SORCERY_OBJECT(details);
    /*! Transaction Timer T1 value */
    unsigned int timert1;
    /*! Transaction Timer B value */
    unsigned int timerb;
    /*! Should we use short forms for headers? */
    unsigned int compactheaders;
    struct {
        /*! Initial number of threads in the threadpool */
        int initial_size;
        /*! The amount by which the number of threads is incremented when necessary */
        int auto_increment;
        /*! Thread idle timeout in seconds */
        int idle_timeout;
        /*! Maxumum number of threads in the threadpool */
        int max_size;
    } threadpool;
    /*! Nonzero to disable switching from UDP to TCP transport */
    unsigned int disable_tcp_switch;
    /*!
     * Although early media is enabled in pjproject by default, it's only
     * enabled when the To tags are different. These options allow turning
     * on or off the feature for different tags and same tags.
     */
    unsigned int follow_early_media_fork;
    unsigned int accept_multiple_sdp_answers;
    /*! Disable the use of rport in outgoing requests */
    unsigned int disable_rport;
};
 
static struct ast_threadpool_options sip_threadpool_options = {
    .version = AST_THREADPOOL_OPTIONS_VERSION,
};
 
void sip_get_threadpool_options(struct ast_threadpool_options *threadpool_options)
{
    *threadpool_options = sip_threadpool_options;
}
 
static struct ast_sorcery *system_sorcery;
 
static void *system_alloc(const char *name)
{
    struct system_config *system = ast_sorcery_generic_alloc(sizeof(*system), NULL);
 
    if (!system) {
        return NULL;
    }
 
    return system;
}
 
static int system_apply(const struct ast_sorcery *sorcery, void *obj)
{
    struct system_config *system = obj;
    int min_timerb;
 
    if (system->timert1 < TIMER_T1_MIN) {
        ast_log(LOG_WARNING, "Timer T1 setting is too low. Setting to %d\n", TIMER_T1_MIN);
        system->timert1 = TIMER_T1_MIN;
    }
 
    min_timerb = 64 * system->timert1;
 
    if (system->timerb < min_timerb) {
        ast_log(LOG_WARNING, "Timer B setting is too low. Setting to %d\n", min_timerb);
        system->timerb = min_timerb;
    }
 
    pjsip_cfg()->tsx.t1 = system->timert1;
    pjsip_cfg()->tsx.td = system->timerb;
 
    pjsip_cfg()->endpt.follow_early_media_fork = system->follow_early_media_fork;
#ifdef HAVE_PJSIP_INV_ACCEPT_MULTIPLE_SDP_ANSWERS
    pjsip_cfg()->endpt.accept_multiple_sdp_answers = system->accept_multiple_sdp_answers;
#else
    if (system->accept_multiple_sdp_answers) {
        ast_log(LOG_WARNING,
            "The accept_multiple_sdp_answers flag is not supported in this version of pjproject. Ignoring\n");
    }
#endif
 
    if (system->compactheaders) {
#ifdef HAVE_PJSIP_ENDPOINT_COMPACT_FORM
        pjsip_cfg()->endpt.use_compact_form = PJ_TRUE;
#else
        extern pj_bool_t pjsip_use_compact_form;
 
        pjsip_use_compact_form = PJ_TRUE;
#endif
    }
 
    sip_threadpool_options.initial_size = system->threadpool.initial_size;
    sip_threadpool_options.auto_increment = system->threadpool.auto_increment;
    sip_threadpool_options.idle_timeout = system->threadpool.idle_timeout;
    sip_threadpool_options.max_size = system->threadpool.max_size;
 
    pjsip_cfg()->endpt.disable_tcp_switch =
        system->disable_tcp_switch ? PJ_TRUE : PJ_FALSE;
 
    pjsip_cfg()->endpt.disable_rport = system->disable_rport ? PJ_TRUE : PJ_FALSE;
 
    return 0;
}
 
static struct system_config *get_system_cfg(void)
{
    struct system_config *cfg;
    struct ao2_container *systems;
    systems = ast_sorcery_retrieve_by_fields(system_sorcery, "system",
        AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL);
 
    if (!systems) {
        return NULL;
    }
 
    cfg = ao2_find(systems, NULL, 0);
    ao2_ref(systems, -1);
    return cfg;
}
 
int sip_cli_print_system(struct ast_sip_cli_context *context)
{
    struct system_config *cfg = get_system_cfg();
 
    if (!cfg) {
        cfg = ast_sorcery_alloc(system_sorcery, "system", NULL);
        if (!cfg) {
            return -1;
        }
    }
 
    ast_str_append(&context->output_buffer, 0, "\nSystem Settings:\n\n");
    ast_sip_cli_print_sorcery_objectset(cfg, context, 0);
 
    ao2_ref(cfg, -1);
    return 0;
}
 
int ast_sip_initialize_system(void)
{
    RAII_VAR(struct ao2_container *, system_configs, NULL, ao2_cleanup);
    RAII_VAR(struct system_config *, system, NULL, ao2_cleanup);
 
    system_sorcery = ast_sorcery_open();
    if (!system_sorcery) {
        ast_log(LOG_ERROR, "Failed to open SIP system sorcery\n");
        return -1;
    }
 
    ast_sorcery_apply_default(system_sorcery, "system", "config", "pjsip.conf,criteria=type=system,single_object=yes,explicit_name=system");
 
    if (ast_sorcery_object_register_no_reload(system_sorcery, "system", system_alloc, NULL, system_apply)) {
        ast_log(LOG_ERROR, "Failed to register with sorcery (is res_sorcery_config loaded?)\n");
        ast_sorcery_unref(system_sorcery);
        system_sorcery = NULL;
        return -1;
    }
 
    ast_sorcery_object_field_register(system_sorcery, "system", "type", "", OPT_NOOP_T, 0, 0);
    ast_sorcery_object_field_register(system_sorcery, "system", "timer_t1", __stringify(DEFAULT_TIMER_T1),
            OPT_UINT_T, 0, FLDSET(struct system_config, timert1));
    ast_sorcery_object_field_register(system_sorcery, "system", "timer_b", __stringify(DEFAULT_TIMER_B),
            OPT_UINT_T, 0, FLDSET(struct system_config, timerb));
    ast_sorcery_object_field_register(system_sorcery, "system", "compact_headers", "no",
            OPT_BOOL_T, 1, FLDSET(struct system_config, compactheaders));
    ast_sorcery_object_field_register(system_sorcery, "system", "threadpool_initial_size", "0",
            OPT_UINT_T, 0, FLDSET(struct system_config, threadpool.initial_size));
    ast_sorcery_object_field_register(system_sorcery, "system", "threadpool_auto_increment", "5",
            OPT_UINT_T, 0, FLDSET(struct system_config, threadpool.auto_increment));
    ast_sorcery_object_field_register(system_sorcery, "system", "threadpool_idle_timeout", "60",
            OPT_UINT_T, 0, FLDSET(struct system_config, threadpool.idle_timeout));
    ast_sorcery_object_field_register(system_sorcery, "system", "threadpool_max_size", "50",
            OPT_UINT_T, 0, FLDSET(struct system_config, threadpool.max_size));
    ast_sorcery_object_field_register(system_sorcery, "system", "disable_tcp_switch", "yes",
            OPT_BOOL_T, 1, FLDSET(struct system_config, disable_tcp_switch));
    ast_sorcery_object_field_register(system_sorcery, "system", "follow_early_media_fork", "yes",
            OPT_BOOL_T, 1, FLDSET(struct system_config, follow_early_media_fork));
    ast_sorcery_object_field_register(system_sorcery, "system", "accept_multiple_sdp_answers", "no",
            OPT_BOOL_T, 1, FLDSET(struct system_config, accept_multiple_sdp_answers));
    ast_sorcery_object_field_register(system_sorcery, "system", "disable_rport", "no",
            OPT_BOOL_T, 1, FLDSET(struct system_config, disable_rport));
 
    ast_sorcery_load(system_sorcery);
 
    system_configs = ast_sorcery_retrieve_by_fields(system_sorcery, "system",
        AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL);
 
    if (ao2_container_count(system_configs)) {
        return 0;
    }
 
    /* No config present, allocate one and apply defaults */
    system = ast_sorcery_alloc(system_sorcery, "system", NULL);
    if (!system) {
        ast_log(LOG_ERROR, "Unable to allocate default system config.\n");
        ast_sorcery_unref(system_sorcery);
        return -1;
    }
 
    if (system_apply(system_sorcery, system)) {
        ast_log(LOG_ERROR, "Failed to apply default system config.\n");
        ast_sorcery_unref(system_sorcery);
        return -1;
    }
 
    return 0;
}
 
void ast_sip_destroy_system(void)
{
    ast_sorcery_unref(system_sorcery);
}
 
static int system_create_resolver_and_set_nameservers(void *data)
{
    struct ao2_container *discovered_nameservers;
    struct ao2_iterator it_nameservers;
    char *nameserver;
    pj_status_t status;
    pj_dns_resolver *resolver;
    pj_str_t nameservers[PJ_DNS_RESOLVER_MAX_NS];
    unsigned int count = 0;
 
    discovered_nameservers = ast_dns_get_nameservers();
    if (!discovered_nameservers) {
        ast_log(LOG_ERROR, "Could not retrieve local system nameservers, resorting to system resolution\n");
        return 0;
    }
 
    if (!ao2_container_count(discovered_nameservers)) {
        ast_log(LOG_ERROR, "There are no local system nameservers configured, resorting to system resolution\n");
        ao2_ref(discovered_nameservers, -1);
        return -1;
    }
 
    if (!(resolver = pjsip_endpt_get_resolver(ast_sip_get_pjsip_endpoint()))) {
        status = pjsip_endpt_create_resolver(ast_sip_get_pjsip_endpoint(), &resolver);
        if (status != PJ_SUCCESS) {
            ast_log(LOG_ERROR, "Could not create DNS resolver(%d), resorting to system resolution\n", status);
            ao2_ref(discovered_nameservers, -1);
            return 0;
        }
    }
 
    it_nameservers = ao2_iterator_init(discovered_nameservers, 0);
    while ((nameserver = ao2_iterator_next(&it_nameservers))) {
        pj_strset2(&nameservers[count++], nameserver);
        ao2_ref(nameserver, -1);
 
        if (count == (PJ_DNS_RESOLVER_MAX_NS - 1)) {
            break;
        }
    }
    ao2_iterator_destroy(&it_nameservers);
 
    status = pj_dns_resolver_set_ns(resolver, count, nameservers, NULL);
 
    /* Since we no longer need the nameservers we can drop the list of them */
    ao2_ref(discovered_nameservers, -1);
 
    if (status != PJ_SUCCESS) {
        ast_log(LOG_ERROR, "Could not set nameservers on DNS resolver in PJSIP(%d), resorting to system resolution\n",
            status);
        return 0;
    }
 
    if (!pjsip_endpt_get_resolver(ast_sip_get_pjsip_endpoint())) {
        status = pjsip_endpt_set_resolver(ast_sip_get_pjsip_endpoint(), resolver);
        if (status != PJ_SUCCESS) {
            ast_log(LOG_ERROR, "Could not set DNS resolver in PJSIP(%d), resorting to system resolution\n", status);
            return 0;
        }
    }
 
    return 0;
}
 
void ast_sip_initialize_dns(void)
{
    ast_sip_push_task_wait_servant(NULL, system_create_resolver_and_set_nameservers, NULL);
}