| /* 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/msc/msc_a.h> |
| #include <osmocom/msc/paging.h> |
| #include <osmocom/msc/transaction.h> |
| #include <osmocom/msc/silent_call.h> |
| |
| #include <osmocom/sigtran/sccp_helpers.h> |
| |
| /* paging of the requested subscriber has completed */ |
| void paging_cb_silent(struct msc_a *msc_a, struct gsm_trans *trans) |
| { |
| struct scall_signal_data sigdata = { |
| .msc_a = msc_a, |
| .vty = trans->silent_call.from_vty, |
| }; |
| struct ran_msg assignment; |
| |
| if (!msc_a) { |
| LOG_MSC_A(msc_a, LOGL_ERROR, "Silent call: MS not responding to Paging\n"); |
| osmo_signal_dispatch(SS_SCALL, S_SCALL_FAILED, &sigdata); |
| trans_free(trans); |
| return; |
| } |
| |
| LOG_MSC_A(msc_a, LOGL_INFO, "Silent call: MS responding to Paging\n"); |
| |
| trans->msc_a = msc_a; |
| msc_a_get(msc_a, MSC_A_USE_SILENT_CALL); |
| |
| osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_TRANSACTION_ACCEPTED, trans); |
| |
| assignment = (struct ran_msg){ |
| .msg_type = RAN_MSG_ASSIGNMENT_COMMAND, |
| .assignment_command = { |
| .channel_type = &trans->silent_call.ct, |
| .cn_rtp = &trans->silent_call.rtp_cn, |
| }, |
| }; |
| if (msc_a_ran_down(msc_a, MSC_ROLE_I, &assignment)) { |
| LOG_MSC_A(msc_a, LOGL_ERROR, "Silent call failed\n"); |
| osmo_signal_dispatch(SS_SCALL, S_SCALL_FAILED, &sigdata); |
| trans_free(trans); |
| } else { |
| osmo_signal_dispatch(SS_SCALL, S_SCALL_SUCCESS, &sigdata); |
| } |
| } |
| |
| void trans_silent_call_free(struct gsm_trans *trans) |
| { |
| struct scall_signal_data sigdata = { |
| .msc_a = trans->msc_a, |
| .vty = trans->silent_call.from_vty, |
| }; |
| osmo_signal_dispatch(SS_SCALL, S_SCALL_DETACHED, &sigdata); |
| } |
| |
| #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, |
| struct vty *vty) |
| { |
| struct gsm_network *net = vsub->vlr->user_ctx; |
| struct gsm_trans *trans; |
| |
| trans = trans_alloc(net, vsub, TRANS_SILENT_CALL, 0, 0); |
| if (trans == NULL) |
| return -ENODEV; |
| |
| trans->silent_call.ct = *ct; |
| if (traffic_dst_ip) { |
| osmo_sockaddr_str_from_str(&trans->silent_call.rtp_cn, traffic_dst_ip, traffic_dst_port); |
| } |
| trans->silent_call.from_vty = vty; |
| |
| if (!paging_request_start(vsub, PAGING_CAUSE_CALL_BACKGROUND, paging_cb_silent, trans, |
| "establish silent call")) { |
| trans_free(trans); |
| return -ENODEV; |
| } |
| |
| return 0; |
| } |
| |
| /* end a silent call with a given subscriber */ |
| int gsm_silent_call_stop(struct vlr_subscr *vsub) |
| { |
| struct msc_a *msc_a = msc_a_for_vsub(vsub, true); |
| struct gsm_trans *trans; |
| if (!msc_a) { |
| 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? */ |
| trans = trans_find_by_type(msc_a, TRANS_SILENT_CALL); |
| if (!trans) { |
| LOG_MSC_A(msc_a, LOGL_ERROR, "Cannot stop silent call, subscriber has no active silent call\n"); |
| return -ENOENT; |
| } |
| |
| trans_free(trans); |
| return 0; |
| } |