gprs_ns2: add member name to bind

Every bind will have a unique name. Add a name argument
to all bind creating functions and require them to be unique.

This is an API break but there wasn't yet a release with NS2.

Change-Id: I8f1d66b7b3b12da12db8b5e6bd08c1beff085b3e
diff --git a/src/gb/gprs_ns2_frgre.c b/src/gb/gprs_ns2_frgre.c
index 423ea4b..014517a 100644
--- a/src/gb/gprs_ns2_frgre.c
+++ b/src/gb/gprs_ns2_frgre.c
@@ -538,6 +538,7 @@
  *  \param[out] result pointer to created bind
  *  \return 0 on success; negative on error */
 int gprs_ns2_frgre_bind(struct gprs_ns2_inst *nsi,
+			const char *name,
 			const struct osmo_sockaddr *local,
 			int dscp,
 			struct gprs_ns2_vc_bind **result)
@@ -546,6 +547,12 @@
 	struct priv_bind *priv;
 	int rc;
 
+	if (!name)
+		return -ENOSPC;
+
+	if (gprs_ns2_bind_by_name(nsi, name))
+		return -EALREADY;
+
 	if (!bind)
 		return -ENOSPC;
 
@@ -554,6 +561,12 @@
 		return -EINVAL;
 	}
 
+	bind->name = talloc_strdup(bind, name);
+	if (!bind->name) {
+		talloc_free(bind);
+		return -ENOSPC;
+	}
+
 	bind->driver = &vc_driver_frgre;
 	bind->ll = GPRS_NS2_LL_FR_GRE;
 	bind->send_vc = frgre_vc_sendmsg;