From 54f5352e0777c6407b47b5d7f9ab366f66179e48 Mon Sep 17 00:00:00 2001
From: Holger Hans Peter Freyther <zecke@selfish.org>
Date: Wed, 27 Oct 2010 11:01:55 +0200
Subject: nat: Close SCCP connections when the USSD Provider is closed.

Send a RLSD down to the BSC in case the USSD Provider is gone. It
is not sending a Clear Command and ut depends if the BS+ will
like this kind of behavior. At least the data on the NAT will
be freed soon afterwards due the RLC message.
---
 openbsc/include/openbsc/bsc_nat.h |  1 +
 openbsc/src/nat/bsc_nat.c         | 37 +++++++++++++++++++++++++++++++++++++
 openbsc/src/nat/bsc_ussd.c        |  5 ++++-
 3 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/openbsc/include/openbsc/bsc_nat.h b/openbsc/include/openbsc/bsc_nat.h
index acecba7de..7c7dde323 100644
--- a/openbsc/include/openbsc/bsc_nat.h
+++ b/openbsc/include/openbsc/bsc_nat.h
@@ -337,5 +337,6 @@ struct gsm48_hdr *bsc_unpack_dtap(struct bsc_nat_parsed *parsed, struct msgb *ms
 /** USSD filtering */
 int bsc_ussd_init(struct bsc_nat *nat);
 int bsc_check_ussd(struct sccp_connections *con, struct bsc_nat_parsed *parsed, struct msgb *msg);
+int bsc_close_ussd_connections(struct bsc_nat *nat);
 
 #endif
diff --git a/openbsc/src/nat/bsc_nat.c b/openbsc/src/nat/bsc_nat.c
index 57818992f..e1d2f3219 100644
--- a/openbsc/src/nat/bsc_nat.c
+++ b/openbsc/src/nat/bsc_nat.c
@@ -231,6 +231,27 @@ static void nat_send_rlsd_msc(struct sccp_connections *conn)
 	queue_for_msc(conn->msc_con, msg);
 }
 
+static void nat_send_rlsd_bsc(struct sccp_connections *conn)
+{
+	struct sccp_connection_released *rel;
+	struct msgb *msg;
+
+	msg = msgb_alloc_headroom(4096, 128, "rlsd");
+	if (!msg) {
+		LOGP(DNAT, LOGL_ERROR, "Failed to allocate clear command.\n");
+		return;
+	}
+
+	msg->l2h = msgb_put(msg, sizeof(*rel));
+	rel = (struct sccp_connection_released *) msg->l2h;
+	rel->type = SCCP_MSG_TYPE_RLSD;
+	rel->release_cause = SCCP_RELEASE_CAUSE_SCCP_FAILURE;
+	rel->destination_local_reference = conn->real_ref;
+	rel->source_local_reference = conn->remote_ref;
+
+	bsc_write(conn->bsc, msg, IPAC_PROTO_SCCP);
+}
+
 static void nat_send_rlc(struct bsc_msc_connection *msc_con,
 			 struct sccp_source_reference *src,
 			 struct sccp_source_reference *dst)
@@ -1307,3 +1328,19 @@ int main(int argc, char **argv)
 
 	return 0;
 }
+
+/* Close all connections handed out to the USSD module */
+int bsc_close_ussd_connections(struct bsc_nat *nat)
+{
+	struct sccp_connections *con;
+	llist_for_each_entry(con, &nat->sccp_connections, list_entry) {
+		if (con->con_local != 2)
+			continue;
+		if (!con->bsc)
+			continue;
+
+		nat_send_rlsd_bsc(con);
+	}
+
+	return 0;
+}
diff --git a/openbsc/src/nat/bsc_ussd.c b/openbsc/src/nat/bsc_ussd.c
index 3729d91f3..f10a871ab 100644
--- a/openbsc/src/nat/bsc_ussd.c
+++ b/openbsc/src/nat/bsc_ussd.c
@@ -61,8 +61,11 @@ static struct bsc_nat_ussd_con *bsc_nat_ussd_alloc(struct bsc_nat *nat)
 
 static void bsc_nat_ussd_destroy(struct bsc_nat_ussd_con *con)
 {
-	if (con->nat->ussd_con == con)
+	if (con->nat->ussd_con == con) {
+		bsc_close_ussd_connections(con->nat);
 		con->nat->ussd_con = NULL;
+	}
+
 	close(con->queue.bfd.fd);
 	bsc_unregister_fd(&con->queue.bfd);
 	bsc_del_timer(&con->auth_timeout);
-- 
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