| /* GSM silent call feature */ |
| |
| /* |
| * (C) 2009 by Harald Welte <laforge@gnumonks.org> |
| * |
| * All Rights Reserved |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU Affero General Public License as published by |
| * the Free Software Foundation; either version 3 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU Affero General Public License for more details. |
| * |
| * You should have received a copy of the GNU Affero General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <errno.h> |
| |
| #include <osmocom/core/msgb.h> |
| #include <openbsc/signal.h> |
| #include <openbsc/debug.h> |
| #include <openbsc/paging.h> |
| #include <openbsc/gsm_data.h> |
| #include <openbsc/gsm_subscriber.h> |
| #include <openbsc/abis_rsl.h> |
| #include <openbsc/chan_alloc.h> |
| #include <openbsc/osmo_msc.h> |
| |
| /* paging of the requested subscriber has completed */ |
| static int paging_cb_silent(unsigned int hooknum, unsigned int event, |
| struct msgb *msg, void *_conn, void *_data) |
| { |
| struct gsm_subscriber_connection *conn = _conn; |
| struct scall_signal_data sigdata; |
| int rc = 0; |
| |
| if (hooknum != GSM_HOOK_RR_PAGING) |
| return -EINVAL; |
| |
| DEBUGP(DSMS, "paging_cb_silent: "); |
| |
| sigdata.conn = conn; |
| sigdata.data = _data; |
| |
| switch (event) { |
| case GSM_PAGING_SUCCEEDED: |
| DEBUGPC(DSMS, "success, using Timeslot %u on ARFCN %u\n", |
| conn->lchan->ts->nr, conn->lchan->ts->trx->arfcn); |
| conn->silent_call = 1; |
| /* increment lchan reference count */ |
| osmo_signal_dispatch(SS_SCALL, S_SCALL_SUCCESS, &sigdata); |
| break; |
| case GSM_PAGING_EXPIRED: |
| case GSM_PAGING_BUSY: |
| case GSM_PAGING_OOM: |
| DEBUGP(DSMS, "expired\n"); |
| osmo_signal_dispatch(SS_SCALL, S_SCALL_EXPIRED, &sigdata); |
| break; |
| default: |
| rc = -EINVAL; |
| break; |
| } |
| |
| return rc; |
| } |
| |
| /* receive a layer 3 message from a silent call */ |
| int silent_call_rx(struct gsm_subscriber_connection *conn, struct msgb *msg) |
| { |
| /* FIXME: do something like sending it through a UDP port */ |
| return 0; |
| } |
| |
| struct msg_match { |
| uint8_t pdisc; |
| uint8_t msg_type; |
| }; |
| |
| /* list of messages that are handled inside OpenBSC, even in a silent call */ |
| static const struct msg_match silent_call_accept[] = { |
| { GSM48_PDISC_MM, GSM48_MT_MM_LOC_UPD_REQUEST }, |
| { GSM48_PDISC_MM, GSM48_MT_MM_CM_SERV_REQ }, |
| }; |
| |
| /* decide if we need to reroute a message as part of a silent call */ |
| int silent_call_reroute(struct gsm_subscriber_connection *conn, struct msgb *msg) |
| { |
| struct gsm48_hdr *gh = msgb_l3(msg); |
| uint8_t pdisc = gh->proto_discr & 0x0f; |
| int i; |
| |
| /* if we're not part of a silent call, never reroute */ |
| if (!conn->silent_call) |
| return 0; |
| |
| /* check if we are a special message that is handled in openbsc */ |
| for (i = 0; i < ARRAY_SIZE(silent_call_accept); i++) { |
| if (silent_call_accept[i].pdisc == pdisc && |
| silent_call_accept[i].msg_type == gh->msg_type) |
| return 0; |
| } |
| |
| /* otherwise, reroute */ |
| return 1; |
| } |
| |
| |
| /* initiate a silent call with a given subscriber */ |
| int gsm_silent_call_start(struct gsm_subscriber *subscr, void *data, int type) |
| { |
| int rc; |
| |
| rc = paging_request(subscr->net, subscr, type, |
| paging_cb_silent, data); |
| return rc; |
| } |
| |
| /* end a silent call with a given subscriber */ |
| int gsm_silent_call_stop(struct gsm_subscriber *subscr) |
| { |
| struct gsm_subscriber_connection *conn; |
| |
| conn = connection_for_subscr(subscr); |
| if (!conn) |
| return -EINVAL; |
| |
| /* did we actually establish a silent call for this guy? */ |
| if (!conn->silent_call) |
| return -EINVAL; |
| |
| conn->silent_call = 0; |
| msc_release_connection(conn); |
| |
| return 0; |
| } |