From b272c5f14909705b19397263ec274e45b9e36507 Mon Sep 17 00:00:00 2001
From: Tymoteusz Bloch <Tymoteusz.Bloch@arm.com>
Date: Thu, 13 Jun 2019 16:34:50 +0200
Subject: [PATCH] Fixed LWIPStack  socket_sendto member to fail if interface
 IP4/6 version differ from destination adress IP version

---
 features/lwipstack/LWIPStack.cpp  | 12 +++++++++++-
 features/lwipstack/lwip_tools.cpp | 11 +++++------
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/features/lwipstack/LWIPStack.cpp b/features/lwipstack/LWIPStack.cpp
index 04ca9d59c96..664337b5ab7 100644
--- a/features/lwipstack/LWIPStack.cpp
+++ b/features/lwipstack/LWIPStack.cpp
@@ -34,6 +34,7 @@
 #include "lwip/dns.h"
 #include "lwip/udp.h"
 #include "lwip/raw.h"
+#include "lwip/netif.h"
 #include "lwip/lwip_errno.h"
 #include "lwip-sys/arch/sys_arch.h"
 
@@ -493,7 +494,16 @@ nsapi_size_or_error_t LWIP::socket_sendto(nsapi_socket_t handle, const SocketAdd
     if (!convert_mbed_addr_to_lwip(&ip_addr, &addr)) {
         return NSAPI_ERROR_PARAMETER;
     }
-
+    struct netif *netif_ = netif_get_by_index(s->conn->pcb.ip->netif_idx);
+    if (!netif_) {
+        netif_ = &default_interface->netif;
+    }
+    if (netif_) {
+        if ((addr.version == NSAPI_IPv4 && !get_ipv4_addr(netif_)) ||
+                (addr.version == NSAPI_IPv6 && !get_ipv6_addr(netif_))) {
+            return NSAPI_ERROR_PARAMETER;
+        }
+    }
     struct netbuf *buf = netbuf_new();
 
     err_t err = netbuf_ref(buf, data, (u16_t)size);
diff --git a/features/lwipstack/lwip_tools.cpp b/features/lwipstack/lwip_tools.cpp
index 29e6bbb7305..c3514cacfc9 100644
--- a/features/lwipstack/lwip_tools.cpp
+++ b/features/lwipstack/lwip_tools.cpp
@@ -59,9 +59,10 @@ nsapi_error_t LWIP::err_remap(err_t err)
     }
 }
 
-#if LWIP_IPV4
+
 const ip_addr_t *LWIP::get_ipv4_addr(const struct netif *netif)
 {
+#if LWIP_IPV4
     if (!netif_is_up(netif)) {
         return NULL;
     }
@@ -69,14 +70,13 @@ const ip_addr_t *LWIP::get_ipv4_addr(const struct netif *netif)
     if (!ip4_addr_isany(netif_ip4_addr(netif))) {
         return netif_ip_addr4(netif);
     }
-
+#endif
     return NULL;
 }
-#endif
 
-#if LWIP_IPV6
 const ip_addr_t *LWIP::get_ipv6_addr(const struct netif *netif)
 {
+#if LWIP_IPV6
     if (!netif_is_up(netif)) {
         return NULL;
     }
@@ -87,10 +87,9 @@ const ip_addr_t *LWIP::get_ipv6_addr(const struct netif *netif)
             return netif_ip_addr6(netif, i);
         }
     }
-
+#endif
     return NULL;
 }
-#endif
 
 bool LWIP::is_local_addr(const ip_addr_t *ip_addr)
 {