From cad1c37fb358fa28104ed27b68f282ed23d73622 Mon Sep 17 00:00:00 2001
From: Valentin Sawadski <valentin@tado.com>
Date: Fri, 18 Sep 2015 14:53:57 +0200
Subject: [PATCH 1/2] Better prints of ::FFFF: prefixed IPv4-mapped addresses

IPv4-mapped Address [1] are now printed accoriding to the text representation
mixed IPv4 and IPv6 networks as specified in [2]

[1] https://tools.ietf.org/html/rfc6890#page-14
[2] https://tools.ietf.org/html/rfc3513#page-5
---
 core/net/ip/ip64-addr.h | 14 ++++++++++++++
 core/net/ip/uip-debug.c | 43 ++++++++++++++++++++++++++++-------------
 2 files changed, 44 insertions(+), 13 deletions(-)

diff --git a/core/net/ip/ip64-addr.h b/core/net/ip/ip64-addr.h
index 4cf80a9b9..3027d846a 100644
--- a/core/net/ip/ip64-addr.h
+++ b/core/net/ip/ip64-addr.h
@@ -34,6 +34,20 @@
 
 #include "net/ip/uip.h"
 
+
+/**
+ * \brief Is IPv4-mapped Address
+ *
+ * See https://tools.ietf.org/html/rfc6890#page-14
+ */
+#define ip64_addr_is_ipv4_mapped_addr(a) \
+  ((((a)->u16[0])  == 0) &&              \
+   (((a)->u16[1])  == 0) &&              \
+   (((a)->u16[2])  == 0) &&              \
+   (((a)->u16[3])  == 0) &&              \
+   (((a)->u16[4])  == 0) &&              \
+   (((a)->u16[5])  == 0xFFFF))
+
 void ip64_addr_copy4(uip_ip4addr_t *dest, const uip_ip4addr_t *src);
 
 void ip64_addr_copy6(uip_ip6addr_t *dest, const uip_ip6addr_t *src);
diff --git a/core/net/ip/uip-debug.c b/core/net/ip/uip-debug.c
index 93e7edfe7..aee023169 100644
--- a/core/net/ip/uip-debug.c
+++ b/core/net/ip/uip-debug.c
@@ -38,6 +38,7 @@
  */
 
 #include "net/ip/uip-debug.h"
+#include "net/ip/ip64-addr.h"
 
 /*---------------------------------------------------------------------------*/
 void
@@ -53,20 +54,36 @@ uip_debug_ipaddr_print(const uip_ipaddr_t *addr)
     return;
   }
 #if NETSTACK_CONF_WITH_IPV6
-  for(i = 0, f = 0; i < sizeof(uip_ipaddr_t); i += 2) {
-    a = (addr->u8[i] << 8) + addr->u8[i + 1];
-    if(a == 0 && f >= 0) {
-      if(f++ == 0) {
-        PRINTA("::");
+  if(ip64_addr_is_ipv4_mapped_addr(addr)) {
+    /* Printing IPv4-mapped addresses is done according to RFC 3513 [1]
+	 *
+	 *     An alternative form that is sometimes more
+	 *     convenient when dealing with a mixed environment
+     *     of IPv4 and IPv6 nodes is x:x:x:x:x:x:d.d.d.d,
+     *     where the 'x's are the hexadecimal values of the
+     *     six high-order 16-bit pieces of the address, and
+     *     the 'd's are the decimal values of the four
+     *     low-order 8-bit pieces of the address (standard
+     *     IPv4 representation).
+     *
+     * [1] https://tools.ietf.org/html/rfc3513#page-5 */
+    PRINTA("::FFFF:%u.%u.%u.%u", addr->u8[12], addr->u8[13], addr->u8[14], addr->u8[15]);
+  } else {
+    for(i = 0, f = 0; i < sizeof(uip_ipaddr_t); i += 2) {
+      a = (addr->u8[i] << 8) + addr->u8[i + 1];
+      if(a == 0 && f >= 0) {
+        if(f++ == 0) {
+          PRINTA("::");
+        }
+      } else {
+        if(f > 0) {
+          f = -1;
+        } else if(i > 0) {
+          PRINTA(":");
+        }
+        PRINTA("%x", a);
       }
-    } else {
-      if(f > 0) {
-        f = -1;
-      } else if(i > 0) {
-        PRINTA(":");
-      }
-      PRINTA("%x", a);
-    }
+	}
   }
 #else /* NETSTACK_CONF_WITH_IPV6 */
   PRINTA("%u.%u.%u.%u", addr->u8[0], addr->u8[1], addr->u8[2], addr->u8[3]);

From 5b818d5a3914d06365a9169d2a6bd5eea8a22ac1 Mon Sep 17 00:00:00 2001
From: Valentin Sawadski <valentin@tado.com>
Date: Wed, 23 Sep 2015 09:25:31 +0200
Subject: [PATCH 2/2] Fixed formatting of documentation

---
 core/net/ip/uip-debug.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/core/net/ip/uip-debug.c b/core/net/ip/uip-debug.c
index aee023169..ab3ba0765 100644
--- a/core/net/ip/uip-debug.c
+++ b/core/net/ip/uip-debug.c
@@ -55,18 +55,20 @@ uip_debug_ipaddr_print(const uip_ipaddr_t *addr)
   }
 #if NETSTACK_CONF_WITH_IPV6
   if(ip64_addr_is_ipv4_mapped_addr(addr)) {
-    /* Printing IPv4-mapped addresses is done according to RFC 3513 [1]
-	 *
-	 *     An alternative form that is sometimes more
-	 *     convenient when dealing with a mixed environment
+    /*
+     * Printing IPv4-mapped addresses is done according to RFC 3513 [1]
+     *
+     *     "An alternative form that is sometimes more
+     *     convenient when dealing with a mixed environment
      *     of IPv4 and IPv6 nodes is x:x:x:x:x:x:d.d.d.d,
      *     where the 'x's are the hexadecimal values of the
      *     six high-order 16-bit pieces of the address, and
      *     the 'd's are the decimal values of the four
      *     low-order 8-bit pieces of the address (standard
-     *     IPv4 representation).
+     *     IPv4 representation)."
      *
-     * [1] https://tools.ietf.org/html/rfc3513#page-5 */
+     * [1] https://tools.ietf.org/html/rfc3513#page-5
+     */
     PRINTA("::FFFF:%u.%u.%u.%u", addr->u8[12], addr->u8[13], addr->u8[14], addr->u8[15]);
   } else {
     for(i = 0, f = 0; i < sizeof(uip_ipaddr_t); i += 2) {