re-structure the OpenBSC directory layout

The new structure divides the code into a number of libraries
for the BSC core functionality, MSC core functionality, Abis transport,
TRAU and other bits.

This doesn't introduce any functional code change but simply moves
around files and alters Makefile.am accordingly.

Next step would be to disentangle a lot of the inter-library
dependencies and make the individual bits of code more independent.

1 files changed, 170 insertions, 0 deletions

diff --git a/openbsc/src/osmo-bsc/osmo_bsc_filter.c b/openbsc/src/osmo-bsc/osmo_bsc_filter.c
new file mode 100644
index 000000000..d2735a63a
--- /dev/null
+++ b/openbsc/src/osmo-bsc/osmo_bsc_filter.c
@@ -0,0 +1,170 @@
+/* (C) 2009-2010 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2009-2010 by On-Waves
+ * 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 <openbsc/osmo_bsc.h>
+#include <openbsc/osmo_msc_data.h>
+#include <openbsc/gsm_04_80.h>
+#include <openbsc/gsm_subscriber.h>
+#include <openbsc/debug.h>
+#include <openbsc/paging.h>
+
+#include <stdlib.h>
+
+static void handle_lu_request(struct gsm_subscriber_connection *conn,
+			      struct msgb *msg)
+{
+	struct gsm48_hdr *gh;
+	struct gsm48_loc_upd_req *lu;
+	struct gsm48_loc_area_id lai;
+	struct gsm_network *net;
+
+	if (msgb_l3len(msg) < sizeof(*gh) + sizeof(*lu)) {
+		LOGP(DMSC, LOGL_ERROR, "LU too small to look at: %u\n", msgb_l3len(msg));
+		return;
+	}
+
+	net = conn->bts->network;
+
+	gh = msgb_l3(msg);
+	lu = (struct gsm48_loc_upd_req *) gh->data;
+
+	gsm48_generate_lai(&lai, net->country_code, net->network_code,
+			   conn->bts->location_area_code);
+
+	if (memcmp(&lai, &lu->lai, sizeof(lai)) != 0) {
+		LOGP(DMSC, LOGL_DEBUG, "Marking con for welcome USSD.\n");
+		conn->sccp_con->new_subscriber = 1;
+	}
+}
+
+/* we will need to stop the paging request */
+static int handle_page_resp(struct gsm_subscriber_connection *conn, struct msgb *msg)
+{
+	uint8_t mi_type;
+	char mi_string[GSM48_MI_SIZE];
+	struct gsm48_hdr *gh;
+	struct gsm48_pag_resp *resp;
+	struct gsm_subscriber *subscr;
+
+	if (msgb_l3len(msg) < sizeof(*gh) + sizeof(*resp)) {
+		LOGP(DMSC, LOGL_ERROR, "PagingResponse too small: %u\n", msgb_l3len(msg));
+		return -1;
+	}
+
+	gh = msgb_l3(msg);
+	resp = (struct gsm48_pag_resp *) &gh->data[0];
+
+	gsm48_paging_extract_mi(resp, msgb_l3len(msg) - sizeof(*gh),
+				mi_string, &mi_type);
+	DEBUGP(DRR, "PAGING RESPONSE: mi_type=0x%02x MI(%s)\n",
+		mi_type, mi_string);
+
+	switch (mi_type) {
+	case GSM_MI_TYPE_TMSI:
+		subscr = subscr_active_by_tmsi(conn->bts->network,
+					       tmsi_from_string(mi_string));
+		break;
+	case GSM_MI_TYPE_IMSI:
+		subscr = subscr_active_by_imsi(conn->bts->network, mi_string);
+		break;
+	default:
+		subscr = NULL;
+		break;
+	}
+
+	if (!subscr) {
+		LOGP(DMSC, LOGL_ERROR, "Non active subscriber got paged.\n");
+		return -1;
+	}
+
+	paging_request_stop(conn->bts, subscr, conn, msg);
+	subscr_put(subscr);
+	return 0;
+}
+
+/**
+ * This is used to scan a message for extra functionality of the BSC. This
+ * includes scanning for location updating requests/acceptd and then send
+ * a welcome USSD message to the subscriber.
+ */
+int bsc_scan_bts_msg(struct gsm_subscriber_connection *conn, struct msgb *msg)
+{
+	struct gsm48_hdr *gh = msgb_l3(msg);
+	uint8_t pdisc = gh->proto_discr & 0x0f;
+	uint8_t mtype = gh->msg_type & 0xbf;
+
+	if (pdisc == GSM48_PDISC_MM) {
+		if (mtype == GSM48_MT_MM_LOC_UPD_REQUEST)
+			handle_lu_request(conn, msg);
+	} else if (pdisc == GSM48_PDISC_RR) {
+		if (mtype == GSM48_MT_RR_PAG_RESP)
+			handle_page_resp(conn, msg);
+	}
+
+	return 0;
+}
+
+static void send_welcome_ussd(struct gsm_subscriber_connection *conn)
+{
+	struct gsm_network *net;
+	net = conn->bts->network;
+
+	if (!net->msc_data->ussd_welcome_txt)
+		return;
+
+	gsm0480_send_ussdNotify(conn, 1, net->msc_data->ussd_welcome_txt);
+	gsm0480_send_releaseComplete(conn);
+}
+
+/**
+ * Messages coming back from the MSC.
+ */
+int bsc_scan_msc_msg(struct gsm_subscriber_connection *conn, struct msgb *msg)
+{
+	struct gsm_network *net;
+	struct gsm48_loc_area_id *lai;
+	struct gsm48_hdr *gh;
+	uint8_t mtype;
+
+	if (msgb_l3len(msg) < sizeof(*gh)) {
+		LOGP(DMSC, LOGL_ERROR, "GSM48 header does not fit.\n");
+		return -1;
+	}
+
+	gh = (struct gsm48_hdr *) msgb_l3(msg);
+	mtype = gh->msg_type & 0xbf;
+	net = conn->bts->network;
+
+	if (mtype == GSM48_MT_MM_LOC_UPD_ACCEPT) {
+		if (net->msc_data->core_ncc != -1 ||
+		    net->msc_data->core_mcc != -1) {
+			if (msgb_l3len(msg) >= sizeof(*gh) + sizeof(*lai)) {
+				lai = (struct gsm48_loc_area_id *) &gh->data[0];
+				gsm48_generate_lai(lai, net->country_code,
+						   net->network_code,
+						   conn->bts->location_area_code);
+			}
+		}
+
+		if (conn->sccp_con->new_subscriber)
+			send_welcome_ussd(conn);
+	}
+
+	return 0;
+}