gprs_ns2: ensure no duplicate UDP NSVC can be created

Change-Id: I58a95817e2730bbbaa851a43a5b072d1de2db037
diff --git a/src/gb/gprs_ns2_udp.c b/src/gb/gprs_ns2_udp.c
index 36f6a97..3081680 100644
--- a/src/gb/gprs_ns2_udp.c
+++ b/src/gb/gprs_ns2_udp.c
@@ -402,6 +402,10 @@
 		return NULL;
 	}
 
+	/* duplicate */
+	if (gprs_ns2_nsvc_by_sockaddr_bind(bind, remote))
+		return NULL;
+
 	sockaddr_str = (char *)osmo_sockaddr_to_str(remote);
 	osmo_identifier_sanitize_buf(sockaddr_str, NULL, '_');
 	snprintf(idbuf, sizeof(idbuf), "%s-NSE%05u-remote-%s", gprs_ns2_lltype_str(nse->ll),
diff --git a/src/gb/gprs_ns2_vty.c b/src/gb/gprs_ns2_vty.c
index 4bd7cde..6214907 100644
--- a/src/gb/gprs_ns2_vty.c
+++ b/src/gb/gprs_ns2_vty.c
@@ -1093,6 +1093,15 @@
 		goto err;
 	}
 
+	nsvc = gprs_ns2_nsvc_by_sockaddr_bind(bind, &remote);
+	if (nsvc) {
+		if (nsvc->nse == nse)
+			vty_out(vty, "Specified NSVC is already present in this NSE.%s", VTY_NEWLINE);
+		else
+			vty_out(vty, "Specified NSVC is already present in another NSE%05u.%s", nsvc->nse->nsei, VTY_NEWLINE);
+		goto err;
+	}
+
 	nsvc = gprs_ns2_ip_connect(bind, &remote, nse, 0);
 	if (!nsvc) {
 		vty_out(vty, "Can not create NS-VC.%s", VTY_NEWLINE);
diff --git a/tests/gb/gprs_ns2_vty.vty b/tests/gb/gprs_ns2_vty.vty
index a969881..f0253fc 100644
--- a/tests/gb/gprs_ns2_vty.vty
+++ b/tests/gb/gprs_ns2_vty.vty
@@ -61,3 +61,23 @@
     NSVCI 00000: udp)[127.0.0.14]:42999<>[127.0.0.17]:9496
     NSVCI 00000: udp)[127.0.0.14]:42999<>[127.0.0.16]:9496
     NSVCI 00000: udp)[127.0.0.14]:42999<>[127.0.0.15]:9496
+OsmoNSdummy# configure terminal
+OsmoNSdummy(config)# ns
+OsmoNSdummy(config-ns)# nse 1234
+OsmoNSdummy(config-ns-nse)# nsvc udp abc 127.0.0.16 9496 signalling-weight 2 data-weight 2
+Specified NSVC is already present in this NSE.
+OsmoNSdummy(config-ns-nse)# exit
+OsmoNSdummy(config-ns)# nse 1235
+OsmoNSdummy(config-ns-nse)# nsvc udp abc 127.0.0.16 9496 signalling-weight 2 data-weight 2
+Specified NSVC is already present in another NSE01234.
+OsmoNSdummy(config-ns-nse)# exit
+OsmoNSdummy(config-ns)# nse 2342
+OsmoNSdummy(config-ns-nse)# ip-sns-bind abc
+OsmoNSdummy(config-ns-nse)# ip-sns-bind abc
+Failed to add ip-sns-bind abc already present
+OsmoNSdummy(config-ns-nse)# ip-sns-bind abc2
+Can not find the given bind 'abc2'
+OsmoNSdummy(config-ns-nse)# ip-sns-remote 127.0.0.1 22222
+OsmoNSdummy(config-ns-nse)# ip-sns-remote 127.0.0.1 22222
+Specified SNS endpoint already part of the NSE.
+OsmoNSdummy(config-ns-nse)# exit