From de9e22177586dc4ed8169d11c33030226cde2d50 Mon Sep 17 00:00:00 2001
From: Christopher Haster <chaster@utexas.edu>
Date: Fri, 12 Aug 2016 18:43:42 -0500
Subject: [PATCH] [nsapi] Added support for NSAPI_REUSEADDR to the lwip
 interface

---
 .../net/FEATURE_IPV4/lwip-interface/lwip_stack.c    | 13 +++++++++++++
 features/net/FEATURE_IPV4/lwip-interface/lwipopts.h |  2 ++
 2 files changed, 15 insertions(+)

diff --git a/features/net/FEATURE_IPV4/lwip-interface/lwip_stack.c b/features/net/FEATURE_IPV4/lwip-interface/lwip_stack.c
index f6f7cbb8ae8..68d93682f77 100644
--- a/features/net/FEATURE_IPV4/lwip-interface/lwip_stack.c
+++ b/features/net/FEATURE_IPV4/lwip-interface/lwip_stack.c
@@ -28,6 +28,7 @@
 #include "lwip/dhcp.h"
 #include "lwip/tcpip.h"
 #include "lwip/tcp.h"
+#include "lwip/ip.h"
 
 
 /* Static arena of sockets */
@@ -415,6 +416,18 @@ static int lwip_setsockopt(nsapi_stack_t *stack, nsapi_socket_t handle, int leve
             s->conn->pcb.tcp->keep_intvl = *(int*)optval;
             return 0;
 
+        case NSAPI_REUSEADDR:
+            if (optlen != sizeof(int)) {
+                return NSAPI_ERROR_UNSUPPORTED;
+            }
+
+            if (*(int *)optval) {
+                s->conn->pcb.tcp->so_options |= SOF_REUSEADDR;
+            } else {
+                s->conn->pcb.tcp->so_options &= ~SOF_REUSEADDR;
+            }
+            return 0;
+
         default:
             return NSAPI_ERROR_UNSUPPORTED;
     }
diff --git a/features/net/FEATURE_IPV4/lwip-interface/lwipopts.h b/features/net/FEATURE_IPV4/lwip-interface/lwipopts.h
index 679784f586c..5e16535ba29 100644
--- a/features/net/FEATURE_IPV4/lwip-interface/lwipopts.h
+++ b/features/net/FEATURE_IPV4/lwip-interface/lwipopts.h
@@ -67,6 +67,8 @@
 #define LWIP_DHCP                   1
 #define LWIP_DNS                    1
 
+#define SO_REUSE                    1
+
 // Support Multicast
 #include "stdlib.h"
 #define LWIP_IGMP                   1