res_pjsip_aoc.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2022, Michael Kuron
 *
 * Michael Kuron <m.kuron@gmx.de>
 *
 * 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>
    <support_level>extended</support_level>
 ***/
 
#include "asterisk.h"
 
#include <pjsip.h>
#include <pjlib.h>
 
#include "asterisk/aoc.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/res_pjsip.h"
#include "asterisk/res_pjsip_session.h"
 
static pj_xml_attr *aoc_xml_create_attr(pj_pool_t *pool, pj_xml_node *node,
    const char *name, const char *value)
{
    pj_xml_attr *attr;
 
    attr = PJ_POOL_ALLOC_T(pool, pj_xml_attr);
 
    pj_strdup2(pool, &attr->name, name);
    pj_strdup2(pool, &attr->value, value);
 
    pj_xml_add_attr(node, attr);
    return attr;
}
 
static pj_xml_node *aoc_xml_create_node(pj_pool_t *pool, pj_xml_node *parent,
    const char *name)
{
    pj_xml_node *node;
 
    node = PJ_POOL_ZALLOC_T(pool, pj_xml_node);
 
    pj_list_init(&node->attr_head);
    pj_list_init(&node->node_head);
 
    pj_strdup2(pool, &node->name, name);
 
    if (parent) {
        pj_xml_add_node(parent, node);
    }
 
    return node;
}
 
static void aoc_xml_set_node_content(pj_pool_t *pool, pj_xml_node *node,
    const char *content)
{
    pj_strdup2(pool, &node->content, content);
}
 
static char * aoc_format_amount(pj_pool_t *pool, unsigned int amount,
        enum ast_aoc_currency_multiplier multiplier)
{
    const size_t amount_max_size = 16;
    char *amount_str;
 
    amount_str = pj_pool_alloc(pool, amount_max_size);
 
    switch (multiplier) {
    case AST_AOC_MULT_ONETHOUSANDTH:
        pj_ansi_snprintf(amount_str, amount_max_size, "%.3f", amount*0.001f);
        break;
    case AST_AOC_MULT_ONEHUNDREDTH:
        pj_ansi_snprintf(amount_str, amount_max_size, "%.2f", amount*0.01f);
        break;
    case AST_AOC_MULT_ONETENTH:
        pj_ansi_snprintf(amount_str, amount_max_size, "%.1f", amount*0.1f);
        break;
    case AST_AOC_MULT_ONE:
        pj_ansi_snprintf(amount_str, amount_max_size, "%d", amount);
        break;
    case AST_AOC_MULT_TEN:
        pj_ansi_snprintf(amount_str, amount_max_size, "%d", amount*10);
        break;
    case AST_AOC_MULT_HUNDRED:
        pj_ansi_snprintf(amount_str, amount_max_size, "%d", amount*100);
        break;
    case AST_AOC_MULT_THOUSAND:
        pj_ansi_snprintf(amount_str, amount_max_size, "%d", amount*1000);
        break;
    default:
        pj_ansi_snprintf(amount_str, amount_max_size, "%d", amount);
    }
 
    return amount_str;
}
 
static const char *aoc_time_scale_str(enum ast_aoc_time_scale value)
{
    const char *str;
 
    switch (value) {
    default:
    case AST_AOC_TIME_SCALE_HUNDREDTH_SECOND:
        str = "one-hundredth-second";
        break;
    case AST_AOC_TIME_SCALE_TENTH_SECOND:
        str = "one-tenth-second";
        break;
    case AST_AOC_TIME_SCALE_SECOND:
        str = "one-second";
        break;
    case AST_AOC_TIME_SCALE_TEN_SECOND:
        str = "ten-seconds";
        break;
    case AST_AOC_TIME_SCALE_MINUTE:
        str = "one-minute";
        break;
    case AST_AOC_TIME_SCALE_HOUR:
        str = "one-hour";
        break;
    case AST_AOC_TIME_SCALE_DAY:
        str = "twenty-four-hours";
        break;
    }
    return str;
}
 
static void aoc_datastore_destroy(void *obj)
{
    char *xml = obj;
    ast_free(xml);
}
 
static const struct ast_datastore_info aoc_s_datastore = {
    .type = "AOC-S",
    .destroy = aoc_datastore_destroy,
};
 
static const struct ast_datastore_info aoc_d_datastore = {
    .type = "AOC-D",
    .destroy = aoc_datastore_destroy,
};
 
static const struct ast_datastore_info aoc_e_datastore = {
    .type = "AOC-E",
    .destroy = aoc_datastore_destroy,
};
 
struct aoc_data {
    struct ast_sip_session *session;
    struct ast_aoc_decoded *decoded;
    enum ast_channel_state channel_state;
};
 
static void aoc_release_pool(void * data)
{
    pj_pool_t *pool = data;
    pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), pool);
}
 
static int aoc_send_as_xml(void * data)
{
    RAII_VAR(struct aoc_data *, adata, data, ao2_cleanup);
    RAII_VAR(pj_pool_t *, pool, NULL, aoc_release_pool);
 
    pool = pjsip_endpt_create_pool(ast_sip_get_pjsip_endpoint(), "AOC", 2048, 512);
 
    if (!pool) {
        ast_log(LOG_ERROR, "Could not create a memory pool for AOC XML\n");
        return 1;
    }
 
    if (ast_aoc_get_msg_type(adata->decoded) == AST_AOC_D ||
            ast_aoc_get_msg_type(adata->decoded) == AST_AOC_E) {
        pj_xml_node *aoc;
        pj_xml_node *aoc_type;
        pj_xml_node *charging_info = NULL;
        pj_xml_node *charges;
        pj_xml_node *charge;
        char *xml;
        size_t size;
        const size_t xml_max_size = 512;
 
        aoc = aoc_xml_create_node(pool, NULL, "aoc");
        aoc_xml_create_attr(pool, aoc, "xmlns",
                "http://uri.etsi.org/ngn/params/xml/simservs/aoc");
        aoc_type = aoc_xml_create_node(pool, aoc,
                ast_aoc_get_msg_type(adata->decoded) == AST_AOC_D ? "aoc-d" : "aoc-e");
        if (ast_aoc_get_msg_type(adata->decoded) == AST_AOC_D) {
            charging_info = aoc_xml_create_node(pool, aoc_type, "charging-info");
            aoc_xml_set_node_content(pool, charging_info,
                    ast_aoc_get_total_type(adata->decoded) == AST_AOC_SUBTOTAL ? "subtotal" : "total");
        }
        charges = aoc_xml_create_node(pool, aoc_type, "recorded-charges");
 
        if (ast_aoc_get_charge_type(adata->decoded) == AST_AOC_CHARGE_FREE) {
            charge = aoc_xml_create_node(pool, charges, "free-charge");
        } else if (ast_aoc_get_charge_type(adata->decoded) == AST_AOC_CHARGE_CURRENCY ||
                ast_aoc_get_charge_type(adata->decoded) == AST_AOC_CHARGE_UNIT) {
            charge = aoc_xml_create_node(pool, charges, "recorded-currency-units");
        } else {
            charge = aoc_xml_create_node(pool, charges, "not-available");
        }
 
        if (ast_aoc_get_charge_type(adata->decoded) == AST_AOC_CHARGE_CURRENCY) {
            const char *currency;
            pj_xml_node *amount;
            char *amount_str;
 
            currency = ast_aoc_get_currency_name(adata->decoded);
            if (!ast_strlen_zero(currency)) {
                pj_xml_node *currency_id;
 
                currency_id = aoc_xml_create_node(pool, charge, "currency-id");
                aoc_xml_set_node_content(pool, currency_id, currency);
            }
 
            amount = aoc_xml_create_node(pool, charge, "currency-amount");
            amount_str = aoc_format_amount(pool, ast_aoc_get_currency_amount(adata->decoded),
                    ast_aoc_get_currency_multiplier(adata->decoded));
            aoc_xml_set_node_content(pool, amount, amount_str);
        } else if (ast_aoc_get_charge_type(adata->decoded) == AST_AOC_CHARGE_UNIT) {
            pj_xml_node *currency_id;
            const struct ast_aoc_unit_entry *unit_entry;
 
            currency_id = aoc_xml_create_node(pool, charge, "currency-id");
            aoc_xml_set_node_content(pool, currency_id, "UNIT");
 
            unit_entry = ast_aoc_get_unit_info(adata->decoded, 0);
            if (unit_entry) {
                pj_xml_node *amount;
                char *amount_str;
 
                amount = aoc_xml_create_node(pool, charge, "currency-amount");
                amount_str = aoc_format_amount(pool, unit_entry->amount,
                        AST_AOC_MULT_ONE);
                aoc_xml_set_node_content(pool, amount, amount_str);
            }
        }
 
        xml = pj_pool_alloc(pool, xml_max_size);
        size = pj_xml_print(aoc, xml, xml_max_size - 1, PJ_TRUE);
        if (size >= xml_max_size) {
            ast_log(LOG_ERROR, "aoc+xml body text too large\n");
            return 1;
        }
        xml[size] = 0;
 
        if (ast_aoc_get_msg_type(adata->decoded) == AST_AOC_D) {
            RAII_VAR(struct ast_datastore *, datastore,
                    ast_sip_session_get_datastore(adata->session, aoc_d_datastore.type),
                    ao2_cleanup);
            struct pjsip_tx_data *tdata;
            struct ast_sip_body body = {
                .type = "application",
                .subtype = "vnd.etsi.aoc+xml",
                .body_text = xml
            };
 
            if (ast_sip_create_request("INFO", adata->session->inv_session->dlg,
                    adata->session->endpoint, NULL, NULL, &tdata)) {
                ast_log(LOG_ERROR, "Could not create AOC INFO request\n");
                return 1;
            }
            if (ast_sip_add_body(tdata, &body)) {
                ast_log(LOG_ERROR, "Could not add body to AOC INFO request\n");
                pjsip_tx_data_dec_ref(tdata);
                return 1;
            }
            ast_sip_session_send_request(adata->session, tdata);
 
            if (!datastore) {
                datastore = ast_sip_session_alloc_datastore(&aoc_d_datastore, aoc_d_datastore.type);
                if (!datastore) {
                    ast_log(LOG_ERROR, "Unable to create datastore for AOC-D.\n");
                    return 1;
                }
                datastore->data = NULL;
                if (ast_sip_session_add_datastore(adata->session, datastore)) {
                    ast_log(LOG_ERROR, "Unable to create datastore for AOC-D.\n");
                    return 1;
                }
            } else {
                ast_free(datastore->data);
            }
 
            aoc_xml_set_node_content(pool, charging_info, "total");
            size = pj_xml_print(aoc, xml, xml_max_size - 1, PJ_TRUE);
            xml[size] = 0;
            datastore->data = ast_strdup(xml);
        } else if (ast_aoc_get_msg_type(adata->decoded) == AST_AOC_E) {
            RAII_VAR(struct ast_datastore *, datastore,
                    ast_sip_session_get_datastore(adata->session, aoc_e_datastore.type),
                    ao2_cleanup);
            if (!datastore) {
                datastore = ast_sip_session_alloc_datastore(&aoc_e_datastore, aoc_e_datastore.type);
                if (!datastore) {
                    ast_log(LOG_ERROR, "Unable to create datastore for AOC-E.\n");
                    return 1;
                }
                datastore->data = NULL;
                if (ast_sip_session_add_datastore(adata->session, datastore)) {
                    ast_log(LOG_ERROR, "Unable to create datastore for AOC-E.\n");
                    return 1;
                }
            } else {
                ast_free(datastore->data);
            }
            datastore->data = ast_strdup(xml);
        }
    } else if (ast_aoc_get_msg_type(adata->decoded) == AST_AOC_S) {
        pj_xml_node *aoc;
        pj_xml_node *aoc_type;
        pj_xml_node *charged_items;
        const struct ast_aoc_s_entry *entry;
        int idx;
        char *xml;
        size_t size;
        const size_t xml_max_size = 1024;
 
        aoc = aoc_xml_create_node(pool, NULL, "aoc");
        aoc_xml_create_attr(pool, aoc, "xmlns",
                "http://uri.etsi.org/ngn/params/xml/simservs/aoc");
        aoc_type = aoc_xml_create_node(pool, aoc, "aoc-s");
        charged_items = aoc_xml_create_node(pool, aoc_type, "charged-items");
 
        for (idx = 0; idx < ast_aoc_s_get_count(adata->decoded); idx++) {
            pj_xml_node *charged_item;
            pj_xml_node *charge;
 
            if (!(entry = ast_aoc_s_get_rate_info(adata->decoded, idx))) {
                break;
            }
 
            if (entry->charged_item == AST_AOC_CHARGED_ITEM_BASIC_COMMUNICATION) {
                charged_item = aoc_xml_create_node(pool, charged_items, "basic");
            } else if (entry->charged_item == AST_AOC_CHARGED_ITEM_CALL_ATTEMPT) {
                charged_item = aoc_xml_create_node(pool, charged_items,
                        "communication-attempt");
            } else if (entry->charged_item == AST_AOC_CHARGED_ITEM_CALL_SETUP) {
                charged_item = aoc_xml_create_node(pool, charged_items,
                        "communication-setup");
            } else {
                continue;
            }
 
            if (entry->rate_type == AST_AOC_RATE_TYPE_FREE) {
                charge = aoc_xml_create_node(pool, charged_item, "free-charge");
            } else if (entry->rate_type == AST_AOC_RATE_TYPE_FLAT) {
                charge = aoc_xml_create_node(pool, charged_item, "flat-rate");
            } else if (entry->rate_type == AST_AOC_RATE_TYPE_DURATION &&
                    entry->charged_item == AST_AOC_CHARGED_ITEM_BASIC_COMMUNICATION) {
                charge = aoc_xml_create_node(pool, charged_item, "price-time");
            } else {
                continue;
            }
 
            if (entry->rate_type == AST_AOC_RATE_TYPE_DURATION ||
                    entry->rate_type == AST_AOC_RATE_TYPE_FLAT) {
                const char *currency;
                pj_xml_node *amount;
                uint32_t amount_val;
                enum ast_aoc_currency_multiplier multiplier_val;
                char *amount_str;
 
                currency = (entry->rate_type == AST_AOC_RATE_TYPE_DURATION ?
                        entry->rate.duration.currency_name :
                        entry->rate.flat.currency_name);
                if (!ast_strlen_zero(currency)) {
                    pj_xml_node *currency_id;
 
                    currency_id = aoc_xml_create_node(pool, charge, "currency-id");
                    aoc_xml_set_node_content(pool, currency_id, currency);
                }
 
                amount = aoc_xml_create_node(pool, charge, "currency-amount");
                amount_val = (entry->rate_type == AST_AOC_RATE_TYPE_DURATION ?
                        entry->rate.duration.amount : entry->rate.flat.amount);
                multiplier_val = (entry->rate_type == AST_AOC_RATE_TYPE_DURATION ?
                        entry->rate.duration.multiplier : entry->rate.flat.multiplier);
                amount_str = aoc_format_amount(pool, amount_val, multiplier_val);
                aoc_xml_set_node_content(pool, amount, amount_str);
            }
 
            if (entry->rate_type == AST_AOC_RATE_TYPE_DURATION) {
                pj_xml_node *length_time_unit;
                pj_xml_node *time_unit;
                char *time_str;
                pj_xml_node *scale;
                pj_xml_node *charging_type;
 
                length_time_unit = aoc_xml_create_node(pool, charge, "length-time-unit");
                time_unit = aoc_xml_create_node(pool, length_time_unit, "time-unit");
                time_str = aoc_format_amount(pool, entry->rate.duration.time,
                        AST_AOC_MULT_ONE);
                aoc_xml_set_node_content(pool, time_unit, time_str);
                scale = aoc_xml_create_node(pool, length_time_unit, "scale");
                aoc_xml_set_node_content(pool, scale,
                        aoc_time_scale_str(entry->rate.duration.time_scale));
                charging_type = aoc_xml_create_node(pool, charge, "charging-type");
                aoc_xml_set_node_content(pool, charging_type,
                        entry->rate.duration.charging_type ? "step-function" :
                        "continuous");
            }
        }
 
        xml = pj_pool_alloc(pool, xml_max_size);
        size = pj_xml_print(aoc, xml, xml_max_size - 1, PJ_TRUE);
        if (size >= xml_max_size) {
            ast_log(LOG_ERROR, "aoc+xml body text too large\n");
            return 1;
        }
        xml[size] = 0;
 
        if (adata->channel_state == AST_STATE_UP ||
                adata->session->call_direction == AST_SIP_SESSION_OUTGOING_CALL) {
            struct pjsip_tx_data *tdata;
            struct ast_sip_body body = {
                .type = "application",
                .subtype = "vnd.etsi.aoc+xml",
                .body_text = xml
            };
 
            if (ast_sip_create_request("INFO", adata->session->inv_session->dlg,
                    adata->session->endpoint, NULL, NULL, &tdata)) {
                ast_log(LOG_ERROR, "Could not create AOC INFO request\n");
                return 1;
            }
            if (ast_sip_add_body(tdata, &body)) {
                ast_log(LOG_ERROR, "Could not add body to AOC INFO request\n");
                pjsip_tx_data_dec_ref(tdata);
                return 1;
            }
            ast_sip_session_send_request(adata->session, tdata);
        } else {
            RAII_VAR(struct ast_datastore *, datastore,
                    ast_sip_session_get_datastore(adata->session, aoc_s_datastore.type),
                    ao2_cleanup);
            if (!datastore) {
                datastore = ast_sip_session_alloc_datastore(&aoc_s_datastore, aoc_s_datastore.type);
                if (!datastore) {
                    ast_log(LOG_ERROR, "Unable to create datastore for AOC-S.\n");
                    return 1;
                }
                if (ast_sip_session_add_datastore(adata->session, datastore)) {
                    ast_log(LOG_ERROR, "Unable to create datastore for AOC-S.\n");
                    return 1;
                }
            } else {
                ast_free(datastore->data);
            }
            datastore->data = ast_strdup(xml);
        }
    }
 
    return 0;
}
 
static void aoc_data_destroy(void * data)
{
    struct aoc_data *adata = data;
 
    ast_aoc_destroy_decoded(adata->decoded);
    ao2_cleanup(adata->session);
}
 
static struct ast_frame *aoc_framehook(struct ast_channel *ast, struct ast_frame *f,
        enum ast_framehook_event event, void *data)
{
    struct ast_sip_channel_pvt *channel;
    struct aoc_data *adata;
 
    if (!f || f->frametype != AST_FRAME_CONTROL || event != AST_FRAMEHOOK_EVENT_WRITE ||
            f->subclass.integer != AST_CONTROL_AOC) {
        return f;
    }
 
    adata = ao2_alloc(sizeof(struct aoc_data), aoc_data_destroy);
    if (!adata) {
        ast_log(LOG_ERROR, "Failed to allocate AOC data\n");
        return f;
    }
 
    adata->decoded = ast_aoc_decode((struct ast_aoc_encoded *) f->data.ptr, f->datalen, ast);
    if (!adata->decoded) {
        ast_log(LOG_ERROR, "Error decoding indicated AOC data\n");
        ao2_ref(adata, -1);
        return f;
    }
 
    channel = ast_channel_tech_pvt(ast);
    adata->session = ao2_bump(channel->session);
    adata->channel_state = ast_channel_state(ast);
 
    if (ast_sip_push_task(adata->session->serializer, aoc_send_as_xml, adata)) {
        ast_log(LOG_ERROR, "Unable to send AOC XML for channel %s\n", ast_channel_name(ast));
        ao2_ref(adata, -1);
    }
    return &ast_null_frame;
}
 
static int aoc_consume(void *data, enum ast_frame_type type)
{
    return (type == AST_FRAME_CONTROL) ? 1 : 0;
}
 
static void aoc_attach_framehook(struct ast_sip_session *session)
{
    int framehook_id;
    static struct ast_framehook_interface hook = {
        .version = AST_FRAMEHOOK_INTERFACE_VERSION,
        .event_cb = aoc_framehook,
        .consume_cb = aoc_consume,
    };
 
    if (!session->channel || !session->endpoint->send_aoc) {
        return;
    }
 
    ast_channel_lock(session->channel);
 
    framehook_id = ast_framehook_attach(session->channel, &hook);
    if (framehook_id < 0) {
        ast_log(LOG_WARNING, "Could not attach AOC Frame hook, AOC will be unavailable on '%s'\n",
            ast_channel_name(session->channel));
    }
 
    ast_channel_unlock(session->channel);
}
 
static int aoc_incoming_invite_request(struct ast_sip_session *session,
        struct pjsip_rx_data *rdata)
{
    aoc_attach_framehook(session);
    return 0;
}
 
static void aoc_outgoing_invite_request(struct ast_sip_session *session,
        struct pjsip_tx_data *tdata)
{
    aoc_attach_framehook(session);
}
 
static void aoc_bye_outgoing_response(struct ast_sip_session *session,
        struct pjsip_tx_data *tdata)
{
    struct ast_sip_body body = {
        .type = "application",
        .subtype = "vnd.etsi.aoc+xml",
    };
    RAII_VAR(struct ast_datastore *, datastore_d, ast_sip_session_get_datastore(session,
            aoc_d_datastore.type), ao2_cleanup);
    RAII_VAR(struct ast_datastore *, datastore_e, ast_sip_session_get_datastore(session,
            aoc_e_datastore.type), ao2_cleanup);
 
    if (datastore_e) {
        body.body_text = datastore_e->data;
    } else if (datastore_d) {
        body.body_text = datastore_d->data;
    }
    else {
        return;
    }
 
    if (ast_sip_add_body(tdata, &body)) {
        ast_log(LOG_ERROR, "Could not add body to AOC INFO request\n");
    }
}
 
static void aoc_bye_outgoing_request(struct ast_sip_session *session,
        struct pjsip_tx_data *tdata)
{
    struct ast_sip_body body = {
        .type = "application",
        .subtype = "vnd.etsi.aoc+xml",
    };
    RAII_VAR(struct ast_datastore *, datastore_d, ast_sip_session_get_datastore(session,
            aoc_d_datastore.type), ao2_cleanup);
    RAII_VAR(struct ast_datastore *, datastore_e, ast_sip_session_get_datastore(session,
            aoc_e_datastore.type), ao2_cleanup);
 
    if (datastore_e) {
        body.body_text = datastore_e->data;
    } else if (datastore_d) {
        body.body_text = datastore_d->data;
    }
    else {
        return;
    }
 
    if (ast_sip_add_body(tdata, &body)) {
        ast_log(LOG_ERROR, "Could not add body to AOC INFO request\n");
    }
}
 
static void aoc_invite_outgoing_response(struct ast_sip_session *session,
        struct pjsip_tx_data *tdata)
{
    pjsip_msg_body *multipart_body;
    pjsip_multipart_part *part;
    pj_str_t body_text;
    pj_str_t type;
    pj_str_t subtype;
    RAII_VAR(struct ast_datastore *, datastore, ast_sip_session_get_datastore(session,
            aoc_s_datastore.type), ao2_cleanup);
 
    if (tdata->msg->line.status.code != 180 && tdata->msg->line.status.code != 183 &&
            tdata->msg->line.status.code != 200) {
        return;
    }
 
    if (!datastore) {
        return;
    }
 
    if (tdata->msg->body && pjsip_media_type_cmp(&tdata->msg->body->content_type,
            &pjsip_media_type_multipart_mixed, 0) == 0) {
        multipart_body = tdata->msg->body;
    } else {
        pjsip_sdp_info *tdata_sdp_info;
 
        tdata_sdp_info = pjsip_tdata_get_sdp_info(tdata);
        if (tdata_sdp_info->sdp) {
            pj_status_t rc;
 
            rc = pjsip_create_multipart_sdp_body(tdata->pool, tdata_sdp_info->sdp,
                    &multipart_body);
            if (rc != PJ_SUCCESS) {
                ast_log(LOG_ERROR, "Unable to create sdp multipart body\n");
                return;
            }
        } else {
            multipart_body = pjsip_multipart_create(tdata->pool,
                    &pjsip_media_type_multipart_mixed, NULL);
        }
    }
 
    part = pjsip_multipart_create_part(tdata->pool);
    pj_strdup2(tdata->pool, &body_text, datastore->data);
    pj_cstr(&type, "application");
    pj_cstr(&subtype, "vnd.etsi.aoc+xml");
    part->body = pjsip_msg_body_create(tdata->pool, &type, &subtype, &body_text);
    pjsip_multipart_add_part(tdata->pool, multipart_body, part);
 
    tdata->msg->body = multipart_body;
}
 
static struct ast_sip_session_supplement aoc_bye_supplement = {
    .method = "BYE",
    .priority = AST_SIP_SUPPLEMENT_PRIORITY_LAST,
    .outgoing_request = aoc_bye_outgoing_request,
    .outgoing_response = aoc_bye_outgoing_response,
};
 
static struct ast_sip_session_supplement aoc_invite_supplement = {
    .method = "INVITE",
    .priority = AST_SIP_SUPPLEMENT_PRIORITY_LAST,
    .incoming_request = aoc_incoming_invite_request,
    .outgoing_request = aoc_outgoing_invite_request,
    .outgoing_response = aoc_invite_outgoing_response,
};
 
static int load_module(void)
{
    ast_sip_session_register_supplement(&aoc_bye_supplement);
    ast_sip_session_register_supplement(&aoc_invite_supplement);
    return AST_MODULE_LOAD_SUCCESS;
}
 
static int unload_module(void)
{
    ast_sip_session_unregister_supplement(&aoc_bye_supplement);
    ast_sip_session_unregister_supplement(&aoc_invite_supplement);
    return 0;
}
 
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP AOC Support",
    .support_level = AST_MODULE_SUPPORT_EXTENDED,
    .load = load_module,
    .unload = unload_module,
    .load_pri = AST_MODPRI_CHANNEL_DEPEND,
    .requires = "res_pjsip",
);