res_pjsip_rfc3326.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * Joshua Colp <jcolp@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.
 */
 
/*** MODULEINFO
    <depend>pjproject</depend>
    <depend>res_pjsip</depend>
    <depend>res_pjsip_session</depend>
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include <pjsip.h>
#include <pjsip_ua.h>
 
#include "asterisk/res_pjsip.h"
#include "asterisk/res_pjsip_session.h"
#include "asterisk/module.h"
#include "asterisk/causes.h"
#include "asterisk/threadpool.h"
 
static void rfc3326_use_reason_header(struct ast_sip_session *session, struct pjsip_rx_data *rdata)
{
    static const pj_str_t str_reason = { "Reason", 6 };
    pjsip_generic_string_hdr *header;
    char buf[128];
    char *cause;
    int code_q850 = 0, code_sip = 0;
 
    header = pjsip_msg_find_hdr_by_name(rdata->msg_info.msg, &str_reason, NULL);
    for (; header;
        header = pjsip_msg_find_hdr_by_name(rdata->msg_info.msg, &str_reason, header->next)) {
        int cause_q850, cause_sip;
        struct ast_control_pvt_cause_code *cause_code;
        int data_size = sizeof(*cause_code);
 
        ast_copy_pj_str(buf, &header->hvalue, sizeof(buf));
        cause = ast_skip_blanks(buf);
        cause_q850 = !strncasecmp(cause, "Q.850", 5);
        cause_sip = !strncasecmp(cause, "SIP", 3);
        if ((cause_q850 || cause_sip) && (cause = strstr(cause, "cause="))) {
            int *code = cause_q850 ? &code_q850 : &code_sip;
            if (sscanf(cause, "cause=%30d", code) != 1) {
                *code = 0;
            }
 
            /* Safe */
            /* Build and send the tech-specific cause information */
            /* size of the string making up the cause code is "SIP " + reason length */
            data_size += 4 + strlen(cause) + 1;
            cause_code = ast_alloca(data_size);
            memset(cause_code, 0, data_size);
            ast_copy_string(cause_code->chan_name, ast_channel_name(session->channel), AST_CHANNEL_NAME);
            snprintf(cause_code->code, data_size, "SIP %s", cause);
 
            cause_code->cause_extended = 1;
            if (code_q850) {
                cause_code->ast_cause = *code & 0x7;
            } else if (code_sip) {
                cause_code->ast_cause = ast_sip_hangup_sip2cause(*code);
            }
            ast_queue_control_data(session->channel, AST_CONTROL_PVT_CAUSE_CODE, cause_code, data_size);
            ast_channel_hangupcause_hash_set(session->channel, cause_code, data_size);
        }
    }
 
    if (code_q850) {
        ast_channel_hangupcause_set(session->channel, code_q850 & 0x7f);
    } else if (code_sip) {
        ast_channel_hangupcause_set(session->channel, ast_sip_hangup_sip2cause(code_sip));
    }
}
 
static int rfc3326_incoming_request(struct ast_sip_session *session, struct pjsip_rx_data *rdata)
{
    if ((pjsip_method_cmp(&rdata->msg_info.msg->line.req.method, &pjsip_bye_method) &&
         pjsip_method_cmp(&rdata->msg_info.msg->line.req.method, &pjsip_cancel_method)) ||
        !session->channel) {
        return 0;
    }
 
    rfc3326_use_reason_header(session, rdata);
 
    return 0;
}
 
static void rfc3326_incoming_response(struct ast_sip_session *session, struct pjsip_rx_data *rdata)
{
    struct pjsip_status_line status = rdata->msg_info.msg->line.status;
 
    if ((status.code < 300) || !session->channel) {
        return;
    }
 
    rfc3326_use_reason_header(session, rdata);
}
 
static void rfc3326_add_reason_header(struct ast_sip_session *session, struct pjsip_tx_data *tdata)
{
    char buf[20];
 
    if (ast_channel_hangupcause(session->channel) == AST_CAUSE_ANSWERED_ELSEWHERE) {
        ast_sip_add_header(tdata, "Reason", "SIP;cause=200;text=\"Call completed elsewhere\"");
    }
 
    if (session->endpoint && session->endpoint->suppress_q850_reason_headers) {
        ast_debug(1, "A Q.850 '%s'(%i) Reason header was suppressed for endpoint '%s'\n",
            ast_cause2str((ast_channel_hangupcause(session->channel) & 0x7f)),
            (ast_channel_hangupcause(session->channel) & 0x7f),
            ast_sorcery_object_get_id(session->endpoint));
    } else {
        snprintf(buf, sizeof(buf), "Q.850;cause=%i", ast_channel_hangupcause(session->channel) & 0x7f);
        ast_sip_add_header(tdata, "Reason", buf);
    }
}
 
static void rfc3326_outgoing_request(struct ast_sip_session *session, struct pjsip_tx_data *tdata)
{
    if ((pjsip_method_cmp(&tdata->msg->line.req.method, &pjsip_bye_method)
            && pjsip_method_cmp(&tdata->msg->line.req.method, &pjsip_cancel_method))
        || !session->channel
        /*
         * The session->channel has been seen to go away on us between
         * checks so we must also be running under the call's serializer
         * thread.
         */
        || session->serializer != ast_threadpool_serializer_get_current()) {
        return;
    }
 
    rfc3326_add_reason_header(session, tdata);
}
 
static void rfc3326_outgoing_response(struct ast_sip_session *session, struct pjsip_tx_data *tdata)
{
    struct pjsip_status_line status = tdata->msg->line.status;
 
    if (status.code < 300
        || !session->channel
        || session->serializer != ast_threadpool_serializer_get_current()) {
        return;
    }
 
    rfc3326_add_reason_header(session, tdata);
}
 
static struct ast_sip_session_supplement rfc3326_supplement = {
    .incoming_request = rfc3326_incoming_request,
    .incoming_response = rfc3326_incoming_response,
    .outgoing_request = rfc3326_outgoing_request,
    .outgoing_response = rfc3326_outgoing_response,
};
 
static int load_module(void)
{
    ast_sip_session_register_supplement(&rfc3326_supplement);
    return AST_MODULE_LOAD_SUCCESS;
}
 
static int unload_module(void)
{
    ast_sip_session_unregister_supplement(&rfc3326_supplement);
    return 0;
}
 
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP RFC3326 Support",
    .support_level = AST_MODULE_SUPPORT_CORE,
    .load = load_module,
    .unload = unload_module,
    .load_pri = AST_MODPRI_APP_DEPEND,
    .requires = "res_pjsip,res_pjsip_session",
);