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authorNeels Hofmeyr <nhofmeyr@sysmocom.de>2016-05-20 21:59:55 +0200
committerNeels Hofmeyr <nhofmeyr@sysmocom.de>2017-06-18 17:49:00 +0200
commit61692adb2b0cd090c8fb8c81376a28bca099d079 (patch)
treebee3b3fde06ec8dc2a4cb9208ceae3465cea25a5 /openbsc/src/libmsc/iucs.c
parent58774cba12ec4675e32fa524cfa631bdc690a9da (diff)
Implement IuCS (large refactoring and addition)
osmo-nitb becomes osmo-msc add DIUCS debug log constant add iucs.[hc] add msc vty, remove nitb vty add libiudummy, to avoid linking Iu deps in tests Use new msc_tx_dtap() instead of gsm0808_submit_dtap() libmgcp: add mgcpgw client API bridge calls via mgcpgw mgcp: hack RAB success from nano3G: patch first RTP payload The ip.access nano3G needs the first RTP payload's first two bytes to read hex 'e400', or it will reject the RAB assignment. Add flag patched_first_rtp_payload to mgcp_rtp_state to detect the first RTP payload on a stream, and overwrite its first bytes with e400. This should probably be configurable, but seems to not harm other femto cells (as long as we patch only the first RTP payload in each stream). Only do this when sending to the BTS side. Change-Id: Ie13ff348117e892d41b8355ab6c24915301eaeaf
Diffstat (limited to 'openbsc/src/libmsc/iucs.c')
-rw-r--r--openbsc/src/libmsc/iucs.c191
1 files changed, 191 insertions, 0 deletions
diff --git a/openbsc/src/libmsc/iucs.c b/openbsc/src/libmsc/iucs.c
new file mode 100644
index 0000000..aeda140
--- /dev/null
+++ b/openbsc/src/libmsc/iucs.c
@@ -0,0 +1,191 @@
+/* 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, link_id %p, conn_id %" PRIx32 "\n",
+ lac, ue->link, 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->link == b->link)
+ && (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, " link %p, conn_id %d",
+ conn->iu.ue_ctx->link,
+ 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 link and
+ * 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: link_id %p, conn_id %" PRIx32 "\n",
+ ue->link, 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 link_id %p, conn_id %" PRIx32 "\n",
+ ue->link, ue->conn_id);
+ return conn;
+ }
+ DEBUGP(DIUCS, "No IuCS subscriber found for link_id %p, conn_id %" PRIx32 "\n",
+ ue->link, 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;
+}