| /* 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/byteswap.h> |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/core/utils.h> |
| #include <osmocom/msc/signal.h> |
| #include <osmocom/msc/debug.h> |
| #include <osmocom/msc/gsm_data.h> |
| #include <osmocom/msc/gsm_subscriber.h> |
| #include <osmocom/msc/vlr.h> |
| |
| #include <osmocom/sigtran/sccp_helpers.h> |
| |
| struct silent_call_data { |
| struct gsm0808_channel_type ct; |
| |
| char traffic_ip[INET_ADDRSTRLEN]; |
| uint16_t traffic_port; |
| |
| void *data; |
| |
| struct osmo_timer_list timer; |
| struct ran_conn *conn; |
| }; |
| |
| static void timer_cb(void *data) |
| { |
| struct silent_call_data *scd = (struct silent_call_data *)data; |
| ran_conn_communicating(scd->conn); |
| talloc_free(scd); |
| } |
| |
| /* 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 silent_call_data *scd = (struct silent_call_data *)_data; |
| struct ran_conn *conn = _conn; |
| struct scall_signal_data sigdata; |
| struct msgb *msg_ass; |
| int rc = 0; |
| int i; |
| |
| if (hooknum != GSM_HOOK_RR_PAGING) |
| return -EINVAL; |
| |
| DEBUGP(DLSMS, "paging_cb_silent: "); |
| |
| sigdata.conn = conn; |
| sigdata.data = scd->data; |
| |
| switch (event) { |
| case GSM_PAGING_SUCCEEDED: |
| #if BEFORE_MSCSPLIT |
| /* Re-enable this log output once we can obtain this information via |
| * A-interface, see OS#2391. */ |
| DEBUGPC(DLSMS, "success, using Timeslot %u on ARFCN %u\n", |
| conn->lchan->ts->nr, conn->lchan->ts->trx->arfcn); |
| #endif |
| conn->silent_call = 1; |
| |
| /* Increment lchan reference count and mark as active*/ |
| ran_conn_get(conn, RAN_CONN_USE_SILENT_CALL); |
| |
| /* Schedule a timer to mark it as active */ |
| /* This is a hack we we can't call ran_conn_communicating |
| * from here because we're in the call back context of |
| * a RAN FSM event but before it actually changes its own |
| * state and it's not ready to accept this. |
| * Of all alternatives considered, making the call in an |
| * 'immediate timer' is the least disruptive and least ugly |
| * way to do it I could find. |
| */ |
| scd->conn = conn; |
| osmo_timer_setup(&scd->timer, timer_cb, scd); |
| osmo_timer_schedule(&scd->timer, 0, 0); |
| |
| /* Manually craft an assignement message with requested mode */ |
| if (scd->ct.ch_indctr == GSM0808_CHAN_SPEECH) { |
| struct gsm0808_speech_codec_list scl; |
| union { |
| struct sockaddr_storage st; |
| struct sockaddr_in in; |
| } rtp_addr; |
| |
| memset(&rtp_addr, 0, sizeof(rtp_addr)); |
| rtp_addr.in.sin_family = AF_INET; |
| rtp_addr.in.sin_port = osmo_htons(scd->traffic_port); |
| rtp_addr.in.sin_addr.s_addr = inet_addr(scd->traffic_ip); |
| |
| for (i = 0; i < scd->ct.perm_spch_len; i++) |
| gsm0808_speech_codec_from_chan_type(&scl.codec[i], scd->ct.perm_spch[i]); |
| scl.len = scd->ct.perm_spch_len; |
| |
| msg_ass = gsm0808_create_ass(&scd->ct, NULL, &rtp_addr.st, &scl, NULL); |
| } else { |
| msg_ass = gsm0808_create_ass(&scd->ct, NULL, NULL, NULL, NULL); |
| } |
| |
| /* Send assignement message, hoping it will work */ |
| osmo_sccp_tx_data_msg(conn->a.scu, conn->a.conn_id, msg_ass); |
| |
| /* Signal completion */ |
| osmo_signal_dispatch(SS_SCALL, S_SCALL_SUCCESS, &sigdata); |
| return 0; |
| |
| case GSM_PAGING_EXPIRED: |
| case GSM_PAGING_BUSY: |
| DEBUGP(DLSMS, "expired\n"); |
| osmo_signal_dispatch(SS_SCALL, S_SCALL_EXPIRED, &sigdata); |
| break; |
| default: |
| rc = -EINVAL; |
| break; |
| } |
| |
| talloc_free(scd); |
| |
| return rc; |
| } |
| |
| #if 0 |
| /* receive a layer 3 message from a silent call */ |
| int silent_call_rx(struct ran_conn *conn, struct msgb *msg) |
| { |
| /* FIXME: do something like sending it through a UDP port */ |
| LOGP(DLSMS, LOGL_NOTICE, "Discarding L3 message from a silent call.\n"); |
| 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 ran_conn *conn, struct msgb *msg) |
| { |
| struct gsm48_hdr *gh = msgb_l3(msg); |
| uint8_t pdisc = gsm48_hdr_pdisc(gh); |
| uint8_t msg_type = gsm48_hdr_msg_type(gh); |
| 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 == msg_type) |
| return 0; |
| } |
| |
| /* otherwise, reroute */ |
| LOGP(DLSMS, LOGL_INFO, "Rerouting L3 message from a silent call.\n"); |
| return 1; |
| } |
| #endif |
| |
| |
| /* initiate a silent call with a given subscriber */ |
| int gsm_silent_call_start(struct vlr_subscr *vsub, |
| const struct gsm0808_channel_type *ct, |
| const char *traffic_dst_ip, uint16_t traffic_dst_port, |
| void *data) |
| { |
| struct subscr_request *req; |
| struct silent_call_data *scd; |
| |
| scd = talloc_zero(vsub, struct silent_call_data); |
| |
| memcpy(&scd->ct, ct, sizeof(scd->ct)); |
| |
| if (traffic_dst_ip) { |
| osmo_strlcpy(scd->traffic_ip, traffic_dst_ip, sizeof(scd->traffic_ip)); |
| scd->traffic_port = traffic_dst_port; |
| } |
| |
| scd->data = data; |
| |
| req = subscr_request_conn(vsub, paging_cb_silent, scd, |
| "establish silent call", |
| SGSAP_SERV_IND_CS_CALL); |
| if (!req) { |
| talloc_free(scd); |
| return -ENODEV; |
| } |
| |
| return 0; |
| } |
| |
| /* end a silent call with a given subscriber */ |
| int gsm_silent_call_stop(struct vlr_subscr *vsub) |
| { |
| struct ran_conn *conn; |
| |
| conn = connection_for_subscr(vsub); |
| if (!conn) { |
| LOGP(DMM, LOGL_ERROR, "%s: Cannot stop silent call, no connection for subscriber\n", |
| vlr_subscr_name(vsub)); |
| return -ENODEV; |
| } |
| |
| /* did we actually establish a silent call for this guy? */ |
| if (!conn->silent_call) { |
| LOGP(DMM, LOGL_ERROR, "%s: Cannot stop silent call, subscriber has no active silent call\n", |
| vlr_subscr_name(vsub)); |
| return -ENOENT; |
| } |
| |
| #if BEFORE_MSCSPLIT |
| /* Re-enable this log output once we can obtain this information via |
| * A-interface, see OS#2391. */ |
| DEBUGPC(DLSMS, "Stopping silent call using Timeslot %u on ARFCN %u\n", |
| conn->lchan->ts->nr, conn->lchan->ts->trx->arfcn); |
| #endif |
| |
| conn->silent_call = 0; |
| ran_conn_put(conn, RAN_CONN_USE_SILENT_CALL); |
| |
| return 0; |
| } |