153 lines
4.1 KiB
C
153 lines
4.1 KiB
C
/* GSM silent call feature */
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/*
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* (C) 2009 by Harald Welte <laforge@gnumonks.org>
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*
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* All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include <stdlib.h>
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#include <unistd.h>
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#include <errno.h>
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#include <osmocom/core/msgb.h>
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#include <openbsc/signal.h>
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#include <openbsc/debug.h>
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#include <openbsc/paging.h>
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#include <openbsc/gsm_data.h>
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#include <openbsc/gsm_subscriber.h>
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#include <openbsc/abis_rsl.h>
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#include <openbsc/chan_alloc.h>
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#include <openbsc/osmo_msc.h>
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/* paging of the requested subscriber has completed */
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static int paging_cb_silent(unsigned int hooknum, unsigned int event,
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struct msgb *msg, void *_conn, void *_data)
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{
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struct gsm_subscriber_connection *conn = _conn;
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struct scall_signal_data sigdata;
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int rc = 0;
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if (hooknum != GSM_HOOK_RR_PAGING)
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return -EINVAL;
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DEBUGP(DLSMS, "paging_cb_silent: ");
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sigdata.conn = conn;
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sigdata.data = _data;
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switch (event) {
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case GSM_PAGING_SUCCEEDED:
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DEBUGPC(DLSMS, "success, using Timeslot %u on ARFCN %u\n",
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conn->lchan->ts->nr, conn->lchan->ts->trx->arfcn);
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conn->silent_call = 1;
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/* increment lchan reference count */
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osmo_signal_dispatch(SS_SCALL, S_SCALL_SUCCESS, &sigdata);
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break;
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case GSM_PAGING_EXPIRED:
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case GSM_PAGING_BUSY:
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case GSM_PAGING_OOM:
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DEBUGP(DLSMS, "expired\n");
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osmo_signal_dispatch(SS_SCALL, S_SCALL_EXPIRED, &sigdata);
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break;
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default:
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rc = -EINVAL;
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break;
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}
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return rc;
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}
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#if 0
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/* receive a layer 3 message from a silent call */
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int silent_call_rx(struct gsm_subscriber_connection *conn, struct msgb *msg)
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{
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/* FIXME: do something like sending it through a UDP port */
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LOGP(DLSMS, LOGL_NOTICE, "Discarding L3 message from a silent call.\n");
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return 0;
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}
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#endif
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struct msg_match {
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uint8_t pdisc;
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uint8_t msg_type;
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};
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/* list of messages that are handled inside OpenBSC, even in a silent call */
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static const struct msg_match silent_call_accept[] = {
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{ GSM48_PDISC_MM, GSM48_MT_MM_LOC_UPD_REQUEST },
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{ GSM48_PDISC_MM, GSM48_MT_MM_CM_SERV_REQ },
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};
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#if 0
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/* decide if we need to reroute a message as part of a silent call */
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int silent_call_reroute(struct gsm_subscriber_connection *conn, struct msgb *msg)
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{
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struct gsm48_hdr *gh = msgb_l3(msg);
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uint8_t pdisc = gsm48_hdr_pdisc(gh);
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uint8_t msg_type = gsm48_hdr_msg_type(gh);
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int i;
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/* if we're not part of a silent call, never reroute */
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if (!conn->silent_call)
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return 0;
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/* check if we are a special message that is handled in openbsc */
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for (i = 0; i < ARRAY_SIZE(silent_call_accept); i++) {
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if (silent_call_accept[i].pdisc == pdisc &&
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silent_call_accept[i].msg_type == msg_type)
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return 0;
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}
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/* otherwise, reroute */
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LOGP(DLSMS, LOGL_INFO, "Rerouting L3 message from a silent call.\n");
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return 1;
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}
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#endif
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/* initiate a silent call with a given subscriber */
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int gsm_silent_call_start(struct gsm_subscriber *subscr, void *data, int type)
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{
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struct subscr_request *req;
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req = subscr_request_channel(subscr, type, paging_cb_silent, data);
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return req != NULL;
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}
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/* end a silent call with a given subscriber */
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int gsm_silent_call_stop(struct gsm_subscriber *subscr)
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{
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struct gsm_subscriber_connection *conn;
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conn = connection_for_subscr(subscr);
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if (!conn)
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return -EINVAL;
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/* did we actually establish a silent call for this guy? */
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if (!conn->silent_call)
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return -EINVAL;
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DEBUGPC(DLSMS, "Stopping silent call using Timeslot %u on ARFCN %u\n",
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conn->lchan->ts->nr, conn->lchan->ts->trx->arfcn);
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conn->silent_call = 0;
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msc_release_connection(conn);
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return 0;
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}
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