| /* Implementation for MSC decisions which interface to send messages out on. */ |
| |
| /* (C) 2016 by sysmocom s.m.f.c GmbH <info@sysmocom.de> |
| * |
| * 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 <osmocom/core/logging.h> |
| |
| #include <osmocom/msc/debug.h> |
| #include <osmocom/msc/gsm_data.h> |
| #include <osmocom/msc/msc_ifaces.h> |
| #include <osmocom/msc/gsm_subscriber.h> |
| #include <osmocom/msc/transaction.h> |
| #include <osmocom/mgcp_client/mgcp_client.h> |
| #include <osmocom/msc/vlr.h> |
| #include <osmocom/msc/a_iface.h> |
| #include <osmocom/msc/gsm_04_08.h> |
| |
| #include "../../bscconfig.h" |
| |
| #ifdef BUILD_IU |
| #include <osmocom/ranap/iu_client.h> |
| extern struct msgb *ranap_new_msg_rab_assign_voice(uint8_t rab_id, |
| uint32_t rtp_ip, |
| uint16_t rtp_port, |
| bool use_x213_nsap); |
| #else |
| #include <osmocom/msc/iu_dummy.h> |
| #endif /* BUILD_IU */ |
| |
| static int msc_tx(struct gsm_subscriber_connection *conn, struct msgb *msg) |
| { |
| if (!msg) |
| return -EINVAL; |
| if (!conn) { |
| msgb_free(msg); |
| return -EINVAL; |
| } |
| |
| DEBUGP(DMSC, "msc_tx %u bytes to %s via %s\n", |
| msg->len, vlr_subscr_name(conn->vsub), |
| ran_type_name(conn->via_ran)); |
| switch (conn->via_ran) { |
| case RAN_GERAN_A: |
| msg->dst = conn; |
| return a_iface_tx_dtap(msg); |
| |
| case RAN_UTRAN_IU: |
| msg->dst = conn->iu.ue_ctx; |
| return ranap_iu_tx(msg, 0); |
| |
| default: |
| LOGP(DMSC, LOGL_ERROR, |
| "msc_tx(): conn->via_ran invalid (%d)\n", |
| conn->via_ran); |
| msgb_free(msg); |
| return -1; |
| } |
| } |
| |
| |
| int msc_tx_dtap(struct gsm_subscriber_connection *conn, |
| struct msgb *msg) |
| { |
| return msc_tx(conn, msg); |
| } |
| |
| |
| /* 9.2.5 CM service accept */ |
| int msc_gsm48_tx_mm_serv_ack(struct gsm_subscriber_connection *conn) |
| { |
| struct msgb *msg; |
| struct gsm48_hdr *gh; |
| |
| if (!conn) |
| return -EINVAL; |
| |
| msg = gsm48_msgb_alloc_name("GSM 04.08 SERV ACC"); |
| |
| gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); |
| gh->proto_discr = GSM48_PDISC_MM; |
| gh->msg_type = GSM48_MT_MM_CM_SERV_ACC; |
| |
| DEBUGP(DMM, "-> CM SERVICE ACCEPT %s\n", |
| vlr_subscr_name(conn->vsub)); |
| |
| return msc_tx_dtap(conn, msg); |
| } |
| |
| /* 9.2.6 CM service reject */ |
| int msc_gsm48_tx_mm_serv_rej(struct gsm_subscriber_connection *conn, |
| enum gsm48_reject_value value) |
| { |
| struct msgb *msg; |
| |
| if (!conn) |
| return -EINVAL; |
| |
| conn->received_cm_service_request = false; |
| |
| msg = gsm48_create_mm_serv_rej(value); |
| if (!msg) { |
| LOGP(DMM, LOGL_ERROR, "Failed to allocate CM Service Reject.\n"); |
| return -1; |
| } |
| |
| DEBUGP(DMM, "-> CM SERVICE Reject cause: %d\n", value); |
| |
| return msc_tx_dtap(conn, msg); |
| } |
| |
| int msc_tx_common_id(struct gsm_subscriber_connection *conn) |
| { |
| if (!conn) |
| return -EINVAL; |
| |
| /* Common ID is only sent over IuCS */ |
| if (conn->via_ran != RAN_UTRAN_IU) { |
| LOGP(DMM, LOGL_INFO, |
| "%s: Asked to transmit Common ID, but skipping" |
| " because this is not on UTRAN\n", |
| vlr_subscr_name(conn->vsub)); |
| return 0; |
| } |
| |
| DEBUGP(DIUCS, "%s: tx CommonID %s\n", |
| vlr_subscr_name(conn->vsub), conn->vsub->imsi); |
| return ranap_iu_tx_common_id(conn->iu.ue_ctx, conn->vsub->imsi); |
| } |
| |
| static int iu_rab_act_cs(struct ranap_ue_conn_ctx *uectx, uint8_t rab_id, |
| uint32_t rtp_ip, uint16_t rtp_port) |
| { |
| #ifdef BUILD_IU |
| struct msgb *msg; |
| bool use_x213_nsap; |
| uint32_t conn_id = uectx->conn_id; |
| |
| use_x213_nsap = (uectx->rab_assign_addr_enc == RANAP_NSAP_ADDR_ENC_X213); |
| |
| LOGP(DIUCS, LOGL_DEBUG, "Assigning RAB: conn_id=%u, rab_id=%d," |
| " rtp=%x:%u, use_x213_nsap=%d\n", conn_id, rab_id, rtp_ip, |
| rtp_port, use_x213_nsap); |
| |
| msg = ranap_new_msg_rab_assign_voice(rab_id, rtp_ip, rtp_port, |
| use_x213_nsap); |
| msg->l2h = msg->data; |
| |
| if (ranap_iu_rab_act(uectx, msg)) |
| LOGP(DIUCS, LOGL_ERROR, "Failed to send RAB Assignment:" |
| " conn_id=%d rab_id=%d rtp=%x:%u\n", |
| conn_id, rab_id, rtp_ip, rtp_port); |
| return 0; |
| #else |
| LOGP(DMSC, LOGL_ERROR, "Cannot send Iu RAB Assignment: built without Iu support\n"); |
| return -ENOTSUP; |
| #endif |
| } |
| |
| static void mgcp_response_rab_act_cs_crcx(struct mgcp_response *r, void *priv) |
| { |
| struct gsm_trans *trans = priv; |
| struct gsm_subscriber_connection *conn = trans->conn; |
| uint32_t rtp_ip; |
| int rc; |
| |
| if (r->head.response_code != 200) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "MGCPGW response yields error: %d %s\n", |
| r->head.response_code, r->head.comment); |
| goto rab_act_cs_error; |
| } |
| |
| rc = mgcp_response_parse_params(r); |
| if (rc) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Cannot parse MGCP response, for %s\n", |
| vlr_subscr_name(trans->vsub)); |
| goto rab_act_cs_error; |
| } |
| |
| conn->rtp.port_cn = r->audio_port; |
| |
| rtp_ip = mgcp_client_remote_addr_n(conn->network->mgw.client); |
| |
| if (trans->conn->via_ran == RAN_UTRAN_IU) { |
| /* Assign a voice channel via RANAP on 3G */ |
| if (iu_rab_act_cs(conn->iu.ue_ctx, conn->iu.rab_id, rtp_ip, conn->rtp.port_subscr)) |
| goto rab_act_cs_error; |
| } else if (trans->conn->via_ran == RAN_GERAN_A) { |
| /* Assign a voice channel via A on 2G */ |
| if (a_iface_tx_assignment(trans)) |
| goto rab_act_cs_error; |
| } else |
| goto rab_act_cs_error; |
| |
| /* Respond back to MNCC (if requested) */ |
| if (trans->tch_rtp_create) { |
| if (gsm48_tch_rtp_create(trans)) |
| goto rab_act_cs_error; |
| } |
| return; |
| |
| rab_act_cs_error: |
| /* FIXME abort call, invalidate conn, ... */ |
| LOGP(DMSC, LOGL_ERROR, "%s: failure during assignment\n", |
| vlr_subscr_name(trans->vsub)); |
| return; |
| } |
| |
| int msc_call_assignment(struct gsm_trans *trans) |
| { |
| struct gsm_subscriber_connection *conn; |
| struct mgcp_client *mgcp; |
| struct msgb *msg; |
| uint16_t bts_base; |
| |
| if (!trans) |
| return -EINVAL; |
| if (!trans->conn) |
| return -EINVAL; |
| |
| conn = trans->conn; |
| mgcp = conn->network->mgw.client; |
| |
| #ifdef BUILD_IU |
| /* FIXME: HACK. where to scope the RAB Id? At the conn / subscriber / ranap_ue_conn_ctx? */ |
| static uint8_t next_iu_rab_id = 1; |
| if (conn->via_ran == RAN_UTRAN_IU) |
| conn->iu.rab_id = next_iu_rab_id ++; |
| #endif |
| |
| conn->rtp.mgcp_rtp_endpoint = |
| mgcp_client_next_endpoint(conn->network->mgw.client); |
| |
| /* This will calculate the port we assign to the BTS via AoIP |
| * assignment command (or rab-assignment on 3G) The BTS will send |
| * its RTP traffic to that port on the MGCPGW side. The MGCPGW only |
| * gets the endpoint ID via the CRCX. It will do the same calculation |
| * on his side too to get knowledge of the rtp port. */ |
| bts_base = mgcp_client_conf_actual(mgcp)->bts_base; |
| conn->rtp.port_subscr = bts_base + 2 * conn->rtp.mgcp_rtp_endpoint; |
| |
| /* Establish the RTP stream first as looping back to the originator. |
| * The MDCX will patch through to the counterpart. TODO: play a ring |
| * tone instead. */ |
| msg = mgcp_msg_crcx(mgcp, conn->rtp.mgcp_rtp_endpoint, |
| conn->rtp.mgcp_rtp_endpoint, MGCP_CONN_LOOPBACK); |
| return mgcp_client_tx(mgcp, msg, mgcp_response_rab_act_cs_crcx, trans); |
| } |
| |
| static void mgcp_response_bridge_mdcx(struct mgcp_response *r, void *priv); |
| |
| static void mgcp_bridge(struct gsm_trans *from, struct gsm_trans *to, |
| enum bridge_state state, |
| enum mgcp_connection_mode mode) |
| { |
| struct gsm_subscriber_connection *conn1 = from->conn; |
| struct gsm_subscriber_connection *conn2 = to->conn; |
| struct mgcp_client *mgcp = conn1->network->mgw.client; |
| const char *ip; |
| struct msgb *msg; |
| |
| OSMO_ASSERT(mgcp); |
| |
| from->bridge.peer = to; |
| from->bridge.state = state; |
| |
| /* Loop back to the same MGCP GW */ |
| ip = mgcp_client_remote_addr_str(mgcp); |
| |
| msg = mgcp_msg_mdcx(mgcp, |
| conn1->rtp.mgcp_rtp_endpoint, |
| ip, conn2->rtp.port_cn, |
| mode); |
| if (mgcp_client_tx(mgcp, msg, mgcp_response_bridge_mdcx, from)) |
| LOGP(DMGCP, LOGL_ERROR, |
| "Failed to send MDCX message for %s\n", |
| vlr_subscr_name(from->vsub)); |
| } |
| |
| static void mgcp_response_bridge_mdcx(struct mgcp_response *r, void *priv) |
| { |
| struct gsm_trans *trans = priv; |
| struct gsm_trans *peer = trans->bridge.peer; |
| |
| switch (trans->bridge.state) { |
| case BRIDGE_STATE_LOOPBACK_PENDING: |
| trans->bridge.state = BRIDGE_STATE_LOOPBACK_ESTABLISHED; |
| |
| switch (peer->bridge.state) { |
| case BRIDGE_STATE_LOOPBACK_PENDING: |
| /* Wait until the other is done as well. */ |
| return; |
| case BRIDGE_STATE_LOOPBACK_ESTABLISHED: |
| /* Now that both are in loopback, switch both to |
| * forwarding. */ |
| mgcp_bridge(trans, peer, BRIDGE_STATE_BRIDGE_PENDING, |
| MGCP_CONN_RECV_SEND); |
| mgcp_bridge(peer, trans, BRIDGE_STATE_BRIDGE_PENDING, |
| MGCP_CONN_RECV_SEND); |
| break; |
| default: |
| LOGP(DMGCP, LOGL_ERROR, |
| "Unexpected bridge state: %d for %s\n", |
| trans->bridge.state, vlr_subscr_name(trans->vsub)); |
| break; |
| } |
| break; |
| |
| case BRIDGE_STATE_BRIDGE_PENDING: |
| trans->bridge.state = BRIDGE_STATE_BRIDGE_ESTABLISHED; |
| break; |
| |
| default: |
| LOGP(DMGCP, LOGL_ERROR, |
| "Unexpected bridge state: %d for %s\n", |
| trans->bridge.state, vlr_subscr_name(trans->vsub)); |
| break; |
| } |
| } |
| |
| int msc_call_connect(struct gsm_trans *trans, uint16_t port, uint32_t ip) |
| { |
| /* With this function we inform the MGCP-GW where (ip/port) it |
| * has to send its outgoing voic traffic. The receiving end will |
| * usually be a PBX (e.g. Asterisk). The IP-Address we tell, will |
| * not only be used to direct the traffic, it will also be used |
| * as a filter to make sure only RTP packets from the right |
| * remote end will reach the BSS. This is also the reason why |
| * inbound audio will not work until this step is performed */ |
| |
| /* NOTE: This function is used when msc_call_bridge(), is not |
| * applicable. This is usually the case when an external MNCC |
| * is in use */ |
| |
| struct gsm_subscriber_connection *conn; |
| struct mgcp_client *mgcp; |
| struct msgb *msg; |
| |
| if (!trans) |
| return -EINVAL; |
| if (!trans->conn) |
| return -EINVAL; |
| if (!trans->conn->network) |
| return -EINVAL; |
| if (!trans->conn->network->mgw.client) |
| return -EINVAL; |
| |
| mgcp = trans->conn->network->mgw.client; |
| |
| struct in_addr ip_addr; |
| ip_addr.s_addr = ntohl(ip); |
| |
| conn = trans->conn; |
| |
| msg = mgcp_msg_mdcx(mgcp, |
| conn->rtp.mgcp_rtp_endpoint, |
| inet_ntoa(ip_addr), port, MGCP_CONN_RECV_SEND); |
| if (mgcp_client_tx(mgcp, msg, NULL, trans)) |
| LOGP(DMGCP, LOGL_ERROR, |
| "Failed to send MDCX message for %s\n", |
| vlr_subscr_name(trans->vsub)); |
| |
| return 0; |
| } |
| |
| int msc_call_bridge(struct gsm_trans *trans1, struct gsm_trans *trans2) |
| { |
| if (!trans1) |
| return -EINVAL; |
| if (!trans2) |
| return -EINVAL; |
| |
| /* First setup as loopback and configure the counterparts' endpoints, |
| * so that when transmission starts the originating addresses are |
| * already known to be valid. The mgcp callback will continue. */ |
| mgcp_bridge(trans1, trans2, BRIDGE_STATE_LOOPBACK_PENDING, |
| MGCP_CONN_LOOPBACK); |
| mgcp_bridge(trans2, trans1, BRIDGE_STATE_LOOPBACK_PENDING, |
| MGCP_CONN_LOOPBACK); |
| |
| return 0; |
| } |
| |
| void msc_call_release(struct gsm_trans *trans) |
| { |
| struct msgb *msg; |
| struct gsm_subscriber_connection *conn; |
| struct mgcp_client *mgcp; |
| |
| if (!trans) |
| return; |
| if (!trans->conn) |
| return; |
| if (!trans->conn->network) |
| return; |
| |
| conn = trans->conn; |
| mgcp = conn->network->mgw.client; |
| |
| /* Send DLCX */ |
| msg = mgcp_msg_dlcx(mgcp, conn->rtp.mgcp_rtp_endpoint, |
| conn->rtp.mgcp_rtp_endpoint); |
| if (mgcp_client_tx(mgcp, msg, NULL, NULL)) |
| LOGP(DMGCP, LOGL_ERROR, |
| "Failed to send DLCX message for %s\n", |
| vlr_subscr_name(trans->vsub)); |
| |
| /* Release endpoint id */ |
| mgcp_client_release_endpoint(conn->rtp.mgcp_rtp_endpoint, mgcp); |
| } |