session: accept lcl ip updates on cl sessions

Allow apps/vcl to provide updated local ips for dgrams. In particular,
allow sessions bound to 0/0 to send data with valid local ips.

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I50a086b1c252731a32a15b6a181ad3dba0c687e0
diff --git a/src/vnet/session/session_node.c b/src/vnet/session/session_node.c
index fd57f08..7a63071 100644
--- a/src/vnet/session/session_node.c
+++ b/src/vnet/session/session_node.c
@@ -1101,6 +1101,8 @@
 	  if (transport_connection_is_cless (ctx->tc))
 	    {
 	      ip_copy (&ctx->tc->rmt_ip, &hdr->rmt_ip, ctx->tc->is_ip4);
+	      ip_copy (&ctx->tc->lcl_ip, &hdr->lcl_ip, ctx->tc->is_ip4);
+	      /* Local port assumed to be bound, not overwriting it */
 	      ctx->tc->rmt_port = hdr->rmt_port;
 	    }
 	  hdr->data_offset += n_bytes_read;