| /* Code to manage MSC subscriber connections over IuCS interface */ |
| |
| /* |
| * (C) 2016,2017 by sysmocom s.f.m.c. GmbH <info@sysmocom.de> |
| * |
| * Author: Neels Hofmeyr <nhofmeyr@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 <inttypes.h> |
| |
| #include <osmocom/core/logging.h> |
| #include <openbsc/debug.h> |
| |
| #include <openbsc/gsm_data.h> |
| #include <openbsc/iu.h> |
| #include <openbsc/gsm_subscriber.h> |
| #include <openbsc/osmo_msc.h> |
| #include <openbsc/vlr.h> |
| |
| /* For A-interface see libbsc/bsc_api.c subscr_con_allocate() */ |
| static struct gsm_subscriber_connection *subscr_conn_allocate_iu(struct gsm_network *network, |
| struct ue_conn_ctx *ue, |
| uint16_t lac) |
| { |
| struct gsm_subscriber_connection *conn; |
| |
| DEBUGP(DIUCS, "Allocating IuCS subscriber conn: lac %d, conn_id %" PRIx32 "\n", |
| lac, ue->conn_id); |
| |
| conn = talloc_zero(network, struct gsm_subscriber_connection); |
| if (!conn) |
| return NULL; |
| |
| conn->network = network; |
| conn->via_ran = RAN_UTRAN_IU; |
| conn->iu.ue_ctx = ue; |
| conn->iu.ue_ctx->rab_assign_addr_enc = network->iu.rab_assign_addr_enc; |
| conn->lac = lac; |
| |
| llist_add_tail(&conn->entry, &network->subscr_conns); |
| return conn; |
| } |
| |
| static int same_ue_conn(struct ue_conn_ctx *a, struct ue_conn_ctx *b) |
| { |
| if (a == b) |
| return 1; |
| return (a->conn_id == b->conn_id); |
| } |
| |
| static inline void log_subscribers(struct gsm_network *network) |
| { |
| if (!log_check_level(DIUCS, LOGL_DEBUG)) |
| return; |
| |
| struct gsm_subscriber_connection *conn; |
| int i = 0; |
| llist_for_each_entry(conn, &network->subscr_conns, entry) { |
| DEBUGP(DIUCS, "%3d: %s", i, vlr_subscr_name(conn->vsub)); |
| switch (conn->via_ran) { |
| case RAN_UTRAN_IU: |
| DEBUGPC(DIUCS, " Iu"); |
| if (conn->iu.ue_ctx) { |
| DEBUGPC(DIUCS, " conn_id %d", |
| conn->iu.ue_ctx->conn_id |
| ); |
| } |
| break; |
| case RAN_GERAN_A: |
| DEBUGPC(DIUCS, " A"); |
| /* TODO log A-interface connection details */ |
| break; |
| case RAN_UNKNOWN: |
| DEBUGPC(DIUCS, " ?"); |
| break; |
| default: |
| DEBUGPC(DIUCS, " invalid"); |
| break; |
| } |
| DEBUGPC(DIUCS, "\n"); |
| i++; |
| } |
| DEBUGP(DIUCS, "subscribers registered: %d\n", i); |
| } |
| |
| /* Return an existing IuCS subscriber connection record for the given |
| * connection IDs, or return NULL if not found. */ |
| struct gsm_subscriber_connection *subscr_conn_lookup_iu( |
| struct gsm_network *network, |
| struct ue_conn_ctx *ue) |
| { |
| struct gsm_subscriber_connection *conn; |
| |
| DEBUGP(DIUCS, "Looking for IuCS subscriber: conn_id %" PRIx32 "\n", |
| ue->conn_id); |
| log_subscribers(network); |
| |
| llist_for_each_entry(conn, &network->subscr_conns, entry) { |
| if (conn->via_ran != RAN_UTRAN_IU) |
| continue; |
| if (!same_ue_conn(conn->iu.ue_ctx, ue)) |
| continue; |
| DEBUGP(DIUCS, "Found IuCS subscriber for conn_id %" PRIx32 "\n", |
| ue->conn_id); |
| return conn; |
| } |
| DEBUGP(DIUCS, "No IuCS subscriber found for conn_id %" PRIx32 "\n", |
| ue->conn_id); |
| return NULL; |
| } |
| |
| /* Receive MM/CC/... message from IuCS (SCCP user SAP). |
| * msg->dst must reference a struct ue_conn_ctx, which identifies the peer that |
| * sent the msg. |
| * |
| * For A-interface see libbsc/bsc_api.c gsm0408_rcvmsg(). */ |
| int gsm0408_rcvmsg_iucs(struct gsm_network *network, struct msgb *msg, |
| uint16_t *lac) |
| { |
| int rc; |
| struct ue_conn_ctx *ue_ctx; |
| struct gsm_subscriber_connection *conn; |
| |
| ue_ctx = (struct ue_conn_ctx*)msg->dst; |
| |
| /* TODO: are there message types that could allow us to skip this |
| * search? */ |
| conn = subscr_conn_lookup_iu(network, ue_ctx); |
| |
| if (conn && lac && (conn->lac != *lac)) { |
| LOGP(DIUCS, LOGL_ERROR, "IuCS subscriber has changed LAC" |
| " within the same connection, discarding connection:" |
| " %s from LAC %d to %d\n", |
| vlr_subscr_name(conn->vsub), conn->lac, *lac); |
| /* Deallocate conn with previous LAC */ |
| msc_subscr_conn_close(conn, GSM_CAUSE_INV_MAND_INFO); |
| /* At this point we could be tolerant and allocate a new |
| * connection, but changing the LAC within the same connection |
| * is shifty. Rather cancel everything. */ |
| return -1; |
| } |
| |
| if (conn) { |
| /* Make sure we don't receive RR over IuCS; otherwise all |
| * messages handled by gsm0408_dispatch() are of interest (CC, |
| * MM, SMS, NS_SS, maybe even MM_GPRS and SM_GPRS). */ |
| struct gsm48_hdr *gh = msgb_l3(msg); |
| uint8_t pdisc = gh->proto_discr & 0x0f; |
| OSMO_ASSERT(pdisc != GSM48_PDISC_RR); |
| |
| msc_dtap(conn, ue_ctx->conn_id, msg); |
| rc = 0; |
| } else { |
| /* allocate a new connection */ |
| |
| if (!lac) { |
| LOGP(DIUCS, LOGL_ERROR, "New IuCS subscriber" |
| " but no LAC available. Expecting an InitialUE" |
| " message containing a LAI IE." |
| " Dropping connection.\n"); |
| return -1; |
| } |
| |
| conn = subscr_conn_allocate_iu(network, ue_ctx, *lac); |
| if (!conn) |
| abort(); |
| |
| /* ownership of conn hereby goes to the MSC: */ |
| rc = msc_compl_l3(conn, msg, 0); |
| } |
| |
| return rc; |
| } |