From 31b0237c501652e6e18f0705e473004f5e20823a Mon Sep 17 00:00:00 2001
From: Dirk Ziegelmeier <dirk@ziegelmeier.net>
Date: Fri, 18 Nov 2016 08:13:15 +0100
Subject: [PATCH] Apply patch #9165: Allowing udp src port to be 0 in cases
 when we don't care about outgoing port

---
 src/core/udp.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/core/udp.c b/src/core/udp.c
index 491fb074..ebb04edc 100644
--- a/src/core/udp.c
+++ b/src/core/udp.c
@@ -283,8 +283,12 @@ udp_input(struct pbuf *p, struct netif *inp)
         uncon_pcb = pcb;
       }
 
-      /* compare PCB remote addr+port to UDP source addr+port */
-      if ((pcb->remote_port == src) &&
+      /* Compare PCB remote addr+port to UDP source addr+port.
+       * Allow pcb->remote_port 0 for matching any port 
+       * from a specified pcb->remote_ip.
+       * See patch #9165
+       */
+      if (((pcb->remote_port == src) || (pcb->remote_port == 0)) &&
           (ip_addr_isany_val(pcb->remote_ip) ||
           ip_addr_cmp(&pcb->remote_ip, ip_current_src_addr()))) {
         /* the first fully matching PCB */