WIP: Collect LAC information from L3 Compl messages

include/osmocom/msc/Makefile.am

@@ -20,6 +20,7 @@ noinst_HEADERS = \
 	mncc.h \
 	mncc_int.h \
 	msc_ifaces.h \
+	msc_lac.h \
 	msc_mgcp.h \
 	openbscdefines.h \
 	a_reset.h \

include/osmocom/msc/gsm_data.h

@@ -347,6 +347,10 @@ struct gsm_network {
 		/* MSISDN to which to route MO emergency calls */
 		char *route_to_msisdn;
 	} emergency;
+
+	/* A list head to keep track on the LACs that are assoctiated with
+	 * this network */
+	struct llist_head lac_contexts;
 };
 
 struct osmo_esme;

include/osmocom/msc/msc_lac.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <stdint.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/msc/gsm_data.h>
+
+/* A struct to keep a context information about the LACs a specific BSC is
+ * associated with */
+struct lac_context {
+	struct llist_head list;
+	uint16_t lac;
+	enum ran_type ran_type;
+	struct bsc_context *bsc_context;
+};
+
+void msc_lac_update_a(struct gsm_network *network, uint16_t lac, struct bsc_context *bsc_context);

src/libmsc/Makefile.am

@@ -42,6 +42,7 @@ libmsc_a_SOURCES = \
 	mncc_builtin.c \
 	mncc_sock.c \
 	msc_ifaces.c \
+	msc_lac.c \
 	msc_mgcp.c \
 	rrlp.c \
 	silent_call.c \

src/libmsc/a_iface_bssap.c

@@ -36,6 +36,7 @@
 #include <osmocom/msc/a_reset.h>
 #include <osmocom/msc/transaction.h>
 #include <osmocom/msc/msc_mgcp.h>
+#include <osmocom/msc/msc_lac.h>
 
 #include <errno.h>
 
@@ -349,6 +350,10 @@ static int bssmap_rx_l3_compl(struct osmo_sccp_user *scu, const struct a_conn_in
 
 	if (rc == MSC_CONN_ACCEPT) {
 		LOGP(DMSC, LOGL_INFO, "User has been accepted by MSC.\n");
+
+		/* Record the LAC in a list for later use (related to other, future operations) */
+		msc_lac_update_a(network, lac, a_conn_info->bsc);
+
 		return 0;
 	} else if (rc == MSC_CONN_REJECT)
 		LOGP(DMSC, LOGL_INFO, "User has been rejected by MSC.\n");

src/libmsc/msc_lac.c

@@ -0,0 +1,51 @@
+/* (C) 2018 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+ * All Rights Reserved
+ *
+ * Author: Philipp Maier
+ *
+ * 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/msc/msc_lac.h>
+#include <stdint.h>
+
+/* Update list with LAC information for a particular BSC */
+void msc_lac_update_a(struct gsm_network *network, uint16_t lac, struct bsc_context *bsc_context)
+{
+	struct lac_context *lac_context;
+	bool create_lac_context = true;
+
+	/* Try to find the lac_context list entry based on the given LAC,
+	 * if one exist, we do not need to create a new one */
+	llist_for_each_entry(lac_context, &network->lac_contexts, list) {
+		if (lac_context->lac == lac) {
+			create_lac_context = false;
+			break;
+		}
+	}
+
+	/* We failed to find an existing LAC context, so we create a new one */
+	if (create_lac_context) {
+		lac_context = talloc_zero(network, struct lac_context);
+		lac_context->lac = lac;
+		llist_add_tail(&lac_context->list, &network->lac_contexts);
+	}
+
+	/* Update context info */
+	lac_context->bsc_context = bsc_context;
+	lac_context->ran_type = RAN_GERAN_A;
+
+	/* TODO: Add some statistical information like timestamps, when created? when last seen? */
+}

src/libmsc/msc_vty.c

@@ -53,6 +53,9 @@
 #include <osmocom/msc/gsm_04_14.h>
 #include <osmocom/msc/signal.h>
 #include <osmocom/msc/mncc_int.h>
+#include <osmocom/msc/a_iface.h>
+#include <osmocom/msc/msc_lac.h>
+#include <osmocom/sigtran/sccp_helpers.h>
 
 static struct gsm_network *gsmnet = NULL;
 
@@ -505,6 +508,43 @@ DEFUN(show_msc_conn, show_msc_conn_cmd,
 	return CMD_SUCCESS;
 }
 
+DEFUN(show_lac, show_lac_cmd, "show lac", SHOW_STR "LAC Information\n")
+{
+	struct lac_context *lac_context;
+	char *sccp_addr_str;
+	char *ran_str;
+	uint16_t lac;
+	struct osmo_sccp_addr *bsc_addr;
+	struct osmo_ss7_instance *ss7;
+
+	vty_out(vty, "--LAC RAN ------------Remote SCCP Address%s",
+		VTY_NEWLINE);
+
+	llist_for_each_entry(lac_context, &gsmnet->lac_contexts, list) {
+
+		lac = lac_context->lac;
+		sccp_addr_str = "(error)";
+
+		if (lac_context->ran_type == RAN_GERAN_A) {
+			ran_str = "A";
+			bsc_addr = &lac_context->bsc_context->bsc_addr;
+			ss7 = osmo_ss7_instance_find(gsmnet->a.cs7_instance);
+			if (bsc_addr && ss7)
+				sccp_addr_str =
+				    osmo_sccp_addr_name(ss7, bsc_addr);
+		} else {
+			/* FIXME: Also add printing for Iu RNC addresses */
+			ran_str = "Iu";
+			sccp_addr_str = "(fixme)";
+		}
+
+		vty_out(vty, "%5u %3s %s%s", lac, ran_str, sccp_addr_str,
+			VTY_NEWLINE);
+	}
+
+	return CMD_SUCCESS;
+}
+
 static void vty_trans_hdr(struct vty *vty)
 {
 	vty_out(vty, "------------Subscriber --ConnId -P TI -CallRef Proto%s",
@@ -1451,6 +1491,7 @@ void msc_vty_init(struct gsm_network *msc_network)
 	install_element_ve(&show_subscr_cmd);
 	install_element_ve(&show_subscr_cache_cmd);
 	install_element_ve(&show_msc_conn_cmd);
+	install_element_ve(&show_lac_cmd);
 	install_element_ve(&show_msc_transaction_cmd);
 
 	install_element_ve(&sms_send_pend_cmd);

src/libmsc/osmo_msc.c

@@ -72,6 +72,7 @@ struct gsm_network *gsm_network_init(void *ctx, mncc_recv_cb_t mncc_recv)
 	net->mncc_recv = mncc_recv;
 
 	INIT_LLIST_HEAD(&net->a.bscs);
+	INIT_LLIST_HEAD(&net->lac_contexts);
 
 	return net;
 }