res_pjsip_caller_id.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.
 */
 
/*** 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/channel.h"
#include "asterisk/module.h"
#include "asterisk/callerid.h"
#include "asterisk/conversions.h"
#include "asterisk/taskpool.h"
 
static int extract_oli(const pjsip_param *param_list, char *buf, size_t len)
{
    static const pj_str_t oli_str1 = { "isup-oli", 8 };
    static const pj_str_t oli_str2 = { "ss7-oli", 7 };
    static const pj_str_t oli_str3 = { "oli", 3 };
    pjsip_param *oli;
 
    if ((oli = pjsip_param_find(param_list, &oli_str1))
        || (oli = pjsip_param_find(param_list, &oli_str2))
        || (oli = pjsip_param_find(param_list, &oli_str3))) {
        ast_copy_pj_str(buf, &oli->value, len);
        return 0;
    }
    return -1;
}
 
/*!
 * \internal
 * \brief Set an ANI2 integer based on OLI data in a From header
 *
 * This uses the contents of a From header in order to set Originating Line information.
 *
 * \param rdata The incoming message
 * \param ani2 The ANI2 field to set
 * \retval 0 Successfully parsed OLI
 * \retval non-zero Could not parse OLI
 */
static int set_id_from_oli(pjsip_rx_data *rdata, int *ani2)
{
    char oli[AST_CHANNEL_NAME];
 
    pjsip_fromto_hdr *from = pjsip_msg_find_hdr(rdata->msg_info.msg,
            PJSIP_H_FROM, rdata->msg_info.msg->hdr.next);
 
    if (!from) {
        return -1; /* This had better not happen */
    }
 
    /* First, check if it was provided as a header paramter */
    if (extract_oli(&from->other_param, oli, sizeof(oli))) {
        /* If not found, check if it was provided as a URI parameter */
        pjsip_sip_uri *uri;
        pjsip_name_addr *name_addr = (pjsip_name_addr *) from->uri;
        if (!ast_sip_is_uri_sip_sips(name_addr->uri)) {
            return -1;
        }
        uri = pjsip_uri_get_uri(name_addr->uri);
        if (extract_oli(&uri->other_param, oli, sizeof(oli))) {
            return -1; /* Not found as either type of parameter */
        }
    }
 
    return ast_str_to_int(oli, ani2);
}
 
/*!
 * \internal
 * \brief Determine if a connected line update should be queued
 *
 * This uses information about the session and the ID that would be queued
 * in the connected line update in order to determine if we should queue
 * a connected line update.
 *
 * \param session The session whose channel we wish to queue the connected line update on
 * \param id The identification information that would be queued on the connected line update
 * \retval 0 We should not queue a connected line update
 * \retval non-zero We should queue a connected line update
 */
static int should_queue_connected_line_update(const struct ast_sip_session *session, const struct ast_party_id *id)
{
    /* Invalid number means no update */
    if (!id->number.valid) {
        return 0;
    }
 
    /* If the session has never communicated an update or if the
     * new ID has a different number than the session, then we
     * should queue an update
     */
    if (ast_strlen_zero(session->id.number.str) ||
            strcmp(session->id.number.str, id->number.str)) {
        return 1;
    }
 
    /* By making it to this point, it means the number is not enough
     * to determine if an update should be sent. Now we look at
     * the name
     */
 
    /* If the number couldn't warrant an update and the name is
     * invalid, then no update
     */
    if (!id->name.valid) {
        return 0;
    }
 
    /* If the name has changed or we don't have a name set for the
     * session, then we should send an update
     */
    if (ast_strlen_zero(session->id.name.str) ||
            strcmp(session->id.name.str, id->name.str)) {
        return 1;
    }
 
    /* Neither the name nor the number have changed. No update */
    return 0;
}
 
/*!
 * \internal
 * \brief Queue a connected line update on a session's channel.
 * \param session The session whose channel should have the connected line update queued upon.
 * \param id The identification information to place in the connected line update
 */
static void queue_connected_line_update(struct ast_sip_session *session, const struct ast_party_id *id)
{
    struct ast_party_connected_line connected;
    struct ast_party_caller caller;
 
    /* Fill connected line information */
    ast_party_connected_line_init(&connected);
    connected.id = *id;
    connected.id.tag = session->endpoint->id.self.tag;
    connected.source = AST_CONNECTED_LINE_UPDATE_SOURCE_ANSWER;
 
    /* Save to channel driver copy */
    ast_party_id_copy(&session->id, &connected.id);
 
    /* Update our channel CALLERID() */
    ast_party_caller_init(&caller);
    caller.id = connected.id;
    caller.ani = connected.id;
    caller.ani2 = ast_channel_caller(session->channel)->ani2;
    ast_channel_set_caller_event(session->channel, &caller, NULL);
 
    /* Tell peer about the new connected line information. */
    ast_channel_queue_connected_line_update(session->channel, &connected, NULL);
}
 
/*!
 * \internal
 * \brief Make updates to connected line information based on an incoming request.
 *
 * This will get identity information from an incoming request. Once the identification is
 * retrieved, we will check if the new information warrants a connected line update and queue
 * a connected line update if so.
 *
 * \param session The session on which we received an incoming request
 * \param rdata The incoming request
 */
static void update_incoming_connected_line(struct ast_sip_session *session, pjsip_rx_data *rdata)
{
    struct ast_party_id id;
 
    if (!session->endpoint->id.trust_connected_line
        || !session->endpoint->id.trust_inbound) {
        return;
    }
 
    ast_party_id_init(&id);
    if (!ast_sip_set_id_connected_line(rdata, &id)) {
        if (should_queue_connected_line_update(session, &id)) {
            queue_connected_line_update(session, &id);
        }
    }
    ast_party_id_free(&id);
}
 
/*!
 * \internal
 * \brief Session supplement callback on an incoming INVITE request
 *
 * If we are receiving an initial INVITE, then we will set the session's identity
 * based on the INVITE or configured endpoint values. If we are receiving a reinvite,
 * then we will potentially queue a connected line update via the \ref update_incoming_connected_line
 * function
 *
 * \param session The session that has received an INVITE
 * \param rdata The incoming INVITE
 */
static int caller_id_incoming_request(struct ast_sip_session *session, pjsip_rx_data *rdata)
{
    if (!session->channel) {
        int ani2;
        /*
         * Since we have no channel this must be the initial inbound
         * INVITE.  Set the session ID directly because the channel
         * has not been created yet.
         */
        ast_sip_set_id_from_invite(rdata, &session->id, &session->endpoint->id.self, session->endpoint->id.trust_inbound);
        session->ani2 = set_id_from_oli(rdata, &ani2) ? 0 : ani2;
    } else {
        /*
         * ReINVITE or UPDATE.  Check for changes to the ID and queue
         * a connected line update if necessary.
         */
        update_incoming_connected_line(session, rdata);
    }
    return 0;
}
 
/*!
 * \internal
 * \brief Session supplement callback on INVITE response
 *
 * INVITE responses could result in queuing connected line updates.
 *
 * \param session The session on which communication is happening
 * \param rdata The incoming INVITE response
 */
static void caller_id_incoming_response(struct ast_sip_session *session, pjsip_rx_data *rdata)
{
    if (!session->channel) {
        return;
    }
 
    update_incoming_connected_line(session, rdata);
}
 
/*!
 * \internal
 * \brief Create an identity header for an outgoing message
 * \param hdr_name The name of the header to create
 * \param base
 * \param tdata The message to place the header on
 * \param id The identification information for the new header
 * \return newly-created header
 */
static pjsip_fromto_hdr *create_new_id_hdr(const pj_str_t *hdr_name, pjsip_fromto_hdr *base, pjsip_tx_data *tdata, const struct ast_party_id *id)
{
    pjsip_fromto_hdr *id_hdr;
    pjsip_name_addr *id_name_addr;
    pjsip_sip_uri *id_uri;
 
    id_hdr = pjsip_from_hdr_create(tdata->pool);
    id_hdr->type = PJSIP_H_OTHER;
    id_hdr->sname = id_hdr->name = *hdr_name;
 
    id_name_addr = pjsip_uri_clone(tdata->pool, base->uri);
    id_uri = pjsip_uri_get_uri(id_name_addr->uri);
 
    if (id->name.valid && !ast_strlen_zero(id->name.str)) {
        int name_buf_len = strlen(id->name.str) * 2 + 1;
        char *name_buf = ast_alloca(name_buf_len);
 
        ast_escape_quoted(id->name.str, name_buf, name_buf_len);
        pj_strdup2(tdata->pool, &id_name_addr->display, name_buf);
    } else {
        /*
         * We need to clear the remnants of the clone or it'll be left set.
         * pj_strdup2 is safe to call with a NULL src and it resets both slen and ptr.
         */
        pj_strdup2(tdata->pool, &id_name_addr->display, NULL);
    }
 
    if (id->number.valid) {
        pj_strdup2(tdata->pool, &id_uri->user, id->number.str);
    } else {
        /* Similar to name, make sure the number is also cleared when invalid */
        pj_strdup2(tdata->pool, &id_uri->user, NULL);
    }
 
    id_hdr->uri = (pjsip_uri *) id_name_addr;
    return id_hdr;
}
 
/*!
 * \internal
 * \brief Add a Privacy header to an outbound message
 *
 * When sending a P-Asserted-Identity header, if privacy is requested, then we
 * will need to indicate such by adding a Privacy header. Similarly, if no
 * privacy is requested, and a Privacy header already exists on the message,
 * then the old Privacy header should be removed.
 *
 * \param tdata The outbound message to add the Privacy header to
 * \param id The id information used to determine privacy
 */
static void add_privacy_header(pjsip_tx_data *tdata, const struct ast_party_id *id)
{
    static const pj_str_t pj_privacy_name = { "Privacy", 7 };
    static const pj_str_t pj_privacy_value = { "id", 2 };
    pjsip_hdr *old_privacy;
 
    old_privacy = pjsip_msg_find_hdr_by_name(tdata->msg, &pj_privacy_name, NULL);
 
    if ((ast_party_id_presentation(id) & AST_PRES_RESTRICTION) == AST_PRES_ALLOWED) {
        if (old_privacy) {
            pj_list_erase(old_privacy);
        }
    } else if (!old_privacy) {
        pjsip_generic_string_hdr *privacy_hdr = pjsip_generic_string_hdr_create(
                tdata->pool, &pj_privacy_name, &pj_privacy_value);
        pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr *)privacy_hdr);
    }
}
 
/*!
 * \internal
 * \brief Add a P-Asserted-Identity header to an outbound message
 * \param session The session on which communication is happening
 * \param tdata The message to add the header to
 * \param id The identification information used to populate the header
 */
static void add_pai_header(const struct ast_sip_session *session, pjsip_tx_data *tdata, const struct ast_party_id *id)
{
    static const pj_str_t pj_pai_name = { "P-Asserted-Identity", 19 };
    pjsip_fromto_hdr *base;
    pjsip_fromto_hdr *pai_hdr;
    pjsip_fromto_hdr *old_pai;
 
    /* Since inv_session reuses responses, we have to make sure there's not already
     * a P-Asserted-Identity present. If there is, we just modify the old one.
     */
    old_pai = pjsip_msg_find_hdr_by_name(tdata->msg, &pj_pai_name, NULL);
    if (old_pai) {
        /* If type is OTHER, then the existing header was most likely
         * added by the PJSIP_HEADER dial plan function as a simple
         * name/value pair.  We can't pass this to modify_id_header because
         * there are no virtual functions to get the uri.  We could parse
         * it into a pjsip_fromto_hdr but it isn't worth it since
         * modify_id_header is just going to overwrite the name and number
         * anyway.  We'll just remove it from the header list instead
         * and create a new one.
         */
        if (old_pai->type == PJSIP_H_OTHER) {
            pj_list_erase(old_pai);
        } else {
            ast_sip_modify_id_header(tdata->pool, old_pai, id);
            add_privacy_header(tdata, id);
            return;
        }
    }
 
    if (tdata->msg->type == PJSIP_REQUEST_MSG) {
        base = session->saved_from_hdr ? session->saved_from_hdr : PJSIP_MSG_FROM_HDR(tdata->msg);
    } else {
        base = PJSIP_MSG_TO_HDR(tdata->msg);
    }
 
    pai_hdr = create_new_id_hdr(&pj_pai_name, base, tdata, id);
    if (!pai_hdr) {
        return;
    }
    add_privacy_header(tdata, id);
 
    pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr *)pai_hdr);
}
 
/*!
 * \internal
 * \brief Add party parameter to a Remote-Party-ID header.
 *
 * \param tdata The message where the Remote-Party-ID header is
 * \param hdr The header on which the parameters are being added
 * \param session The session involved
 */
static void add_party_param(pjsip_tx_data *tdata, pjsip_fromto_hdr *hdr, const struct ast_sip_session *session)
{
    static const pj_str_t party_str = { "party", 5 };
    static const pj_str_t calling_str = { "calling", 7 };
    static const pj_str_t called_str = { "called", 6 };
    pjsip_param *party;
 
    /* The party value can't change throughout the lifetime, so it is set only once */
    party = pjsip_param_find(&hdr->other_param, &party_str);
    if (party) {
        return;
    }
 
    party = PJ_POOL_ALLOC_T(tdata->pool, pjsip_param);
    party->name = party_str;
    party->value = (session->inv_session->role == PJSIP_ROLE_UAC) ? calling_str : called_str;
    pj_list_insert_before(&hdr->other_param, party);
}
 
/*!
 * \internal
 * \brief Add privacy and screen parameters to a Remote-Party-ID header.
 *
 * If privacy is requested, then the privacy and screen parameters need to
 * reflect this. Similarly, if no privacy or screening is to be communicated,
 * we need to make sure that any previously set values are updated.
 *
 * \param tdata The message where the Remote-Party-ID header is
 * \param hdr The header on which the parameters are being added
 * \param id The identification information used to determine privacy
 */
static void add_privacy_params(pjsip_tx_data *tdata, pjsip_fromto_hdr *hdr, const struct ast_party_id *id)
{
    static const pj_str_t privacy_str = { "privacy", 7 };
    static const pj_str_t screen_str = { "screen", 6 };
    static const pj_str_t privacy_full_str = { "full", 4 };
    static const pj_str_t privacy_off_str = { "off", 3 };
    static const pj_str_t screen_yes_str = { "yes", 3 };
    static const pj_str_t screen_no_str = { "no", 2 };
    pjsip_param *old_privacy;
    pjsip_param *old_screen;
    pjsip_param *privacy;
    pjsip_param *screen;
    int presentation;
 
    old_privacy = pjsip_param_find(&hdr->other_param, &privacy_str);
    old_screen = pjsip_param_find(&hdr->other_param, &screen_str);
 
    if (!old_privacy) {
        privacy = PJ_POOL_ALLOC_T(tdata->pool, pjsip_param);
        privacy->name = privacy_str;
        pj_list_insert_before(&hdr->other_param, privacy);
    } else {
        privacy = old_privacy;
    }
 
    if (!old_screen) {
        screen = PJ_POOL_ALLOC_T(tdata->pool, pjsip_param);
        screen->name = screen_str;
        pj_list_insert_before(&hdr->other_param, screen);
    } else {
        screen = old_screen;
    }
 
    presentation = ast_party_id_presentation(id);
    if ((presentation & AST_PRES_RESTRICTION) == AST_PRES_ALLOWED) {
        privacy->value = privacy_off_str;
    } else {
        privacy->value = privacy_full_str;
    }
    if ((presentation & AST_PRES_NUMBER_TYPE) == AST_PRES_USER_NUMBER_PASSED_SCREEN) {
        screen->value = screen_yes_str;
    } else {
        screen->value = screen_no_str;
    }
}
 
/*!
 * \internal
 * \brief Add a Remote-Party-ID header to an outbound message
 * \param session The session on which communication is happening
 * \param tdata The message to add the header to
 * \param id The identification information used to populate the header
 */
static void add_rpid_header(const struct ast_sip_session *session, pjsip_tx_data *tdata, const struct ast_party_id *id)
{
    static const pj_str_t pj_rpid_name = { "Remote-Party-ID", 15 };
    pjsip_fromto_hdr *base;
    pjsip_fromto_hdr *rpid_hdr;
    pjsip_fromto_hdr *old_rpid;
 
    /* Since inv_session reuses responses, we have to make sure there's not already
     * a P-Asserted-Identity present. If there is, we just modify the old one.
     */
    old_rpid = pjsip_msg_find_hdr_by_name(tdata->msg, &pj_rpid_name, NULL);
    if (old_rpid) {
        /* If type is OTHER, then the existing header was most likely
         * added by the PJSIP_HEADER dial plan function as a simple
         * name/value pair.  We can't pass this to modify_id_header because
         * there are no virtual functions to get the uri.  We could parse
         * it into a pjsip_fromto_hdr but it isn't worth it since
         * modify_id_header is just going to overwrite the name and number
         * anyway.  We'll just remove it from the header list instead
         * and create a new one.
         */
        if (old_rpid->type == PJSIP_H_OTHER) {
            pj_list_erase(old_rpid);
        } else {
            ast_sip_modify_id_header(tdata->pool, old_rpid, id);
            add_party_param(tdata, old_rpid, session);
            add_privacy_params(tdata, old_rpid, id);
            return;
        }
    }
 
    if (tdata->msg->type == PJSIP_REQUEST_MSG) {
        base = session->saved_from_hdr ? session->saved_from_hdr : PJSIP_MSG_FROM_HDR(tdata->msg);
    } else {
        base = PJSIP_MSG_TO_HDR(tdata->msg);
    }
 
    rpid_hdr = create_new_id_hdr(&pj_rpid_name, base, tdata, id);
    if (!rpid_hdr) {
        return;
    }
    add_party_param(tdata, rpid_hdr, session);
    add_privacy_params(tdata, rpid_hdr, id);
    pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr *)rpid_hdr);
}
 
/*!
 * \internal
 * \brief Add any appropriate identification headers to an outbound SIP message
 *
 * This will determine if an outbound message should have identification headers and
 * will add the appropriately configured headers
 *
 * \param session The session on which we will be sending the message
 * \param tdata The outbound message
 * \param id The identity information to place on the message
 */
static void add_id_headers(const struct ast_sip_session *session, pjsip_tx_data *tdata, const struct ast_party_id *id)
{
    if (!ast_sip_can_present_connected_id(session, id)) {
        return;
    }
    if (session->endpoint->id.send_pai) {
        add_pai_header(session, tdata, id);
    }
    if (session->endpoint->id.send_rpid) {
        add_rpid_header(session, tdata, id);
    }
}
 
/*!
 * \internal
 * \brief Session supplement callback for outgoing INVITE requests
 *
 * On all INVITEs (initial and reinvite) we may add other identity headers
 * such as P-Asserted-Identity and Remote-Party-ID based on configuration
 * and privacy settings
 *
 * \param session The session on which the INVITE will be sent
 * \param tdata The outbound INVITE request
 */
static void caller_id_outgoing_request(struct ast_sip_session *session, pjsip_tx_data *tdata)
{
    struct ast_party_id effective_id;
    struct ast_party_id connected_id;
 
    if (!session->channel) {
        return;
    }
 
    ast_party_id_init(&connected_id);
    ast_channel_lock(session->channel);
    effective_id = ast_channel_connected_effective_id(session->channel);
    ast_party_id_copy(&connected_id, &effective_id);
    ast_channel_unlock(session->channel);
 
    add_id_headers(session, tdata, &connected_id);
    ast_party_id_free(&connected_id);
}
 
/*!
 * \internal
 * \brief Session supplement for outgoing INVITE response
 *
 * This will add P-Asserted-Identity and Remote-Party-ID headers if necessary
 *
 * \param session The session on which the INVITE response is to be sent
 * \param tdata The outbound INVITE response
 */
static void caller_id_outgoing_response(struct ast_sip_session *session, pjsip_tx_data *tdata)
{
    struct ast_party_id effective_id;
    struct ast_party_id connected_id;
 
    /*
     * Outgoing response callbacks may execute on the PJSIP monitor
     * thread during retransmissions, outside the session serializer.
     * The channel pointer can change during a masquerade, potentially
     * causing a channel mutex to remain locked.
     *
     * Retransmitted responses already contain the caller ID information
     * added when the response was first sent, so skipping this callback
     * outside the serializer does not change the response contents.
     */
    if (session->serializer != ast_taskpool_serializer_get_current()
        || !session->channel
        || (!session->endpoint->id.send_connected_line
            && session->inv_session
            && session->inv_session->state >= PJSIP_INV_STATE_EARLY)) {
        return;
    }
 
    /* Must do a deep copy unless we hold the channel lock the entire time. */
    ast_party_id_init(&connected_id);
    ast_channel_lock(session->channel);
    effective_id = ast_channel_connected_effective_id(session->channel);
    ast_party_id_copy(&connected_id, &effective_id);
    ast_channel_unlock(session->channel);
 
    add_id_headers(session, tdata, &connected_id);
    ast_party_id_free(&connected_id);
}
 
static struct ast_sip_session_supplement caller_id_supplement = {
    .method = "INVITE,UPDATE",
    .priority = AST_SIP_SUPPLEMENT_PRIORITY_CHANNEL - 1000,
    .incoming_request = caller_id_incoming_request,
    .incoming_response = caller_id_incoming_response,
    .outgoing_request = caller_id_outgoing_request,
    .outgoing_response = caller_id_outgoing_response,
};
 
static int load_module(void)
{
    ast_module_shutdown_ref(AST_MODULE_SELF);
    ast_sip_session_register_supplement(&caller_id_supplement);
    return AST_MODULE_LOAD_SUCCESS;
}
 
static int unload_module(void)
{
    ast_sip_session_unregister_supplement(&caller_id_supplement);
    return 0;
}
 
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP Caller ID 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",
);