From dd351a350184d84a5866dabc498b4c8be4d51abd Mon Sep 17 00:00:00 2001
From: twinaphex <libretro@gmail.com>
Date: Wed, 13 Sep 2017 03:05:28 +0200
Subject: [PATCH] (Xbox) Provide implementation function for inet_ntop_compat

---
 libretro-common/net/net_compat.c | 159 ++++++++++++++++++++++++++++++-
 1 file changed, 155 insertions(+), 4 deletions(-)

diff --git a/libretro-common/net/net_compat.c b/libretro-common/net/net_compat.c
index 91d6a99d6e..d9de1d8ceb 100644
--- a/libretro-common/net/net_compat.c
+++ b/libretro-common/net/net_compat.c
@@ -348,10 +348,10 @@ uint16_t inet_htons(uint16_t hostshort)
 }
 
 #ifdef _XBOX
-static int inet_aton(const char *cp, struct in_addr *addr)
-{
-  addr->s_addr = inet_addr(cp);
-  return (addr->s_addr == INADDR_NONE) ? 0 : 1;
+static int inet_aton(const char *cp, struct in_addr *addr)
+{
+  addr->s_addr = inet_addr(cp);
+  return (addr->s_addr == INADDR_NONE) ? 0 : 1;
 }
 #endif
 
@@ -372,12 +372,163 @@ struct in_addr6_compat
    unsigned char ip_addr[16];
 };
 
+#ifdef _XBOX
+
+#ifndef IM_IN6ADDRSZ
+#define	IM_IN6ADDRSZ	16
+#endif
+
+#ifndef IM_INT16SZ
+#define	IM_INT16SZ		2
+#endif
+
+#ifndef IM_INADDRSZ
+#define	IM_INADDRSZ		4
+#endif
+/* Taken from https://github.com/skywind3000/easenet/blob/master/inetbase.c 
+ */
+
+/* convert presentation format to network format */
+static const char *
+inet_ntop4x(const unsigned char *src, char *dst, size_t size)
+{
+   char tmp[64];
+   size_t len = snprintf(tmp,
+         sizeof(tmp),
+         "%u.%u.%u.%u", src[0], src[1], src[2], src[3]);
+
+   if (len >= size)
+      goto error;
+
+   memcpy(dst, tmp, len + 1);
+   return dst;
+
+error:
+   errno = ENOSPC;
+   return NULL;
+}
+
+
+/* convert presentation format to network format */
+static const char *
+inet_ntop6x(const unsigned char *src, char *dst, size_t size)
+{
+   char tmp[64], *tp;
+   int i, inc;
+   struct { int base, len; } best, cur;
+   unsigned int words[IM_IN6ADDRSZ / IM_INT16SZ];
+
+   memset(words, '\0', sizeof(words));
+   best.base = best.len = 0;
+   cur.base  = cur.len  = 0;
+
+   for (i = 0; i < IM_IN6ADDRSZ; i++)
+      words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
+
+   best.base = -1;
+   cur.base  = -1;
+
+   for (i = 0; i < (IM_IN6ADDRSZ / IM_INT16SZ); i++)
+   {
+      if (words[i] == 0)
+      {
+         if (cur.base == -1)
+         {
+            cur.base = i;
+            cur.len  = 1;
+         }
+         else cur.len++;
+      } 
+      else
+      {
+         if (cur.base != -1)
+         {
+            if (best.base == -1 || cur.len > best.len)
+               best = cur;
+            cur.base = -1;
+         }
+      }
+   }
+   if (cur.base != -1)
+   {
+      if (best.base == -1 || cur.len > best.len)
+         best = cur;
+   }
+   if (best.base != -1 && best.len < 2)
+      best.base = -1;
+
+   tp = tmp;
+   for (i = 0; i < (IM_IN6ADDRSZ / IM_INT16SZ); i++)
+   {
+      if (best.base != -1 && i >= best.base &&
+            i < (best.base + best.len))
+      {
+         if (i == best.base)
+            *tp++ = ':';
+         continue;
+      }
+
+      if (i != 0)
+         *tp++ = ':';
+      if (i == 6 && best.base == 0 &&
+            (best.len == 6 || (best.len == 5 && words[5] == 0xffff)))
+      {
+         if (!inet_ntop4x(src+12, tp, sizeof(tmp) - (tp - tmp)))
+            return NULL;
+         tp += strlen(tp);
+         break;
+      }
+      inc = sprintf(tp, "%x", words[i]);
+      tp += inc;
+   }
+
+   if (best.base != -1 && (best.base + best.len) == 
+         (IM_IN6ADDRSZ / IM_INT16SZ)) 
+      *tp++ = ':';
+
+   *tp++ = '\0';
+
+   if ((size_t)(tp - tmp) > size)
+      goto error;
+
+   memcpy(dst, tmp, tp - tmp);
+   return dst;
+
+error:
+   errno = ENOSPC;
+   return NULL;
+}
+
+/* convert network format to presentation format */
+/* another inet_ntop, supports AF_INET/AF_INET6 */
+static const char *isockaddr_ntop(int af,
+      const void *src, char *dst, size_t size)
+{
+   switch (af)
+   {
+      case AF_INET:
+         return inet_ntop4x((const unsigned char*)src, dst, size);
+#ifdef AF_INET6
+      case AF_INET6:
+         return inet_ntop6x((const unsigned char*)src, dst, size);
+#endif
+      default:
+         if (af == -6)
+            return inet_ntop6x((const unsigned char*)src, dst, size);
+         errno = EAFNOSUPPORT;
+         return NULL;
+   }
+}
+#endif
+
 const char *inet_ntop_compat(int af, const void *src, char *dst, socklen_t cnt)
 {
 #if defined(VITA) || defined(__ORBIS__)
    return sceNetInetNtop(af,src,dst,cnt);
 #elif defined(WIIU)
    return inet_ntop(af, src, dst, cnt);
+#elif defined(_XBOX)
+   return isockaddr_ntop(af, src, dst, cnt);
 #elif defined(_WIN32)
    if (af == AF_INET)
    {