Everything converted to ipv6.

You still can connect to ipv4 via IPv4-Mapped IPv6 Addresses.

Incompatible lib ABI.

Squashed commit of the following:

commit d643eb3
Merge: c3fec7a 9ce6c59
Author: proller <proller@github.com>
Date:   Mon Oct 31 23:06:18 2016 +0300

    Merge branch 'master' into ipv6

commit c3fec7a
Merge: 1f8eb62 f46fee0
Author: proller <proller@github.com>
Date:   Fri Sep 16 13:16:45 2016 +0300

    Merge remote-tracking branch 'upstream/master' into ipv6

commit 1f8eb62
Author: proller <proller@github.com>
Date:   Sat Mar 12 02:11:52 2016 +0300

    support sin6_scope_id in address

commit f499bc5
Merge: 720e7c4 4d10671
Author: proller <proller@github.com>
Date:   Sat Mar 12 01:14:00 2016 +0300

    Merge remote-tracking branch 'upstream/master' into ipv6

commit 720e7c4
Author: proller <proller@github.com>
Date:   Thu Dec 17 01:17:38 2015 +0300

    return setting ENET_SOCKOPT_IPV6_V6ONLY=>0 after bind

commit b048473
Author: proller <proller@github.com>
Date:   Sat Sep 26 11:40:41 2015 +0400

    fix win32 compiler warning

commit 5a9492d
Merge: 09018e4 2a567b0
Author: proller <proller@users.noreply.github.com>
Date:   Tue Aug 25 18:12:34 2015 +0300

    Merge pull request #1 from K-os/ipv6

    Allow connecting to IPv4 addresses

commit 2a567b0
Author: Gabriel Hege <g+github@hege.cc>
Date:   Mon Aug 24 12:07:09 2015 +0200

    Set socket option IPV6_V6ONLY before bind()

commit 2b52599
Author: Gabriel Hege <g+github@hege.cc>
Date:   Mon Aug 24 12:11:09 2015 +0200

    Handle IPv4/v6 addresses returend from getaddrinfo

commit a91524f
Author: Gabriel Hege <g+github@hege.cc>
Date:   Thu Aug 13 19:25:17 2015 +0200

    gethostbyname(): Use correct address family AF_INET6

    for result from gethostbyname()

commit 90620b2
Author: Gabriel Hege <g+github@hege.cc>
Date:   Thu Aug 13 19:26:41 2015 +0200

    Fail or Warn, when getaddrinfo(), inet_pton() and friends are missing

commit 09018e4
Author: proller <proller@github.com>
Date:   Mon May 11 22:03:48 2015 +0300

    fix

commit a2651c6
Merge: 2c1bac4 62755b1
Author: proller <proller@github.com>
Date:   Mon May 11 20:28:46 2015 +0300

    Merge branch 'master' into ipv6

    Conflicts:
    	unix.c

commit 2c1bac4
Author: proller <proller@github.com>
Date:   Mon May 11 17:53:49 2015 +0300

    add IPV6_V6ONLY socket option = 0

commit 52b0da7
Author: proller <proller@github.com>
Date:   Tue May 5 22:37:06 2015 +0400

    very ugly win32 fix

commit 1394392
Merge: e236d01 b1758c4
Author: proller <proller@github.com>
Date:   Mon May 4 22:45:36 2015 +0300

    Merge branch 'master' into ipv6

commit e236d01
Author: proller <proller@github.com>
Date:   Mon May 4 19:41:47 2015 +0400

    fix aton types

commit 0ff6534
Merge: cf46ab3 c10af34
Author: proller <proller@github.com>
Date:   Fri Apr 10 23:40:21 2015 +0300

    Merge remote-tracking branch 'origin/master' into ipv6

    Conflicts:
    	include/enet/win32.h

commit cf46ab3
Author: proller <proller@github.com>
Date:   Mon Apr 6 03:20:12 2015 +0300

    win32: fix include order

commit b9de5d2
Merge: 3f5bab2 a2eb357
Author: proller <proller@github.com>
Date:   Sun Apr 5 03:38:19 2015 +0300

    Merge branch 'master' into ipv6

    Conflicts:
    	unix.c

commit 3f5bab2
Author: proller <proller@github.com>
Date:   Fri Jan 9 21:05:50 2015 +0300

    fix inet_ntoa

commit 7d9fa2b
Author: proller <proller@github.com>
Date:   Tue Dec 16 23:53:47 2014 +0300

    fix win32 build errors

commit 04394e6
Author: proller <proller@github.com>
Date:   Wed Dec 3 01:07:18 2014 +0300

    apple fix

commit 9122c46
Merge: b3f2bf9 b8ae4a1
Author: proller <proller@github.com>
Date:   Wed Dec 3 01:01:51 2014 +0300

    Merge branch 'master' into ipv6

commit b3f2bf9
Merge: 512a43b 8096edb
Author: proller <proller@github.com>
Date:   Wed Oct 8 17:07:54 2014 +0400

    Merge branch 'master' into ipv6

commit 512a43b
Author: proller <proller@github.com>
Date:   Thu Jul 3 18:46:25 2014 +0400

    Copypaste resolving functions from unix.c to win32.c

commit dce98b9
Author: proller <proller@github.com>
Date:   Wed May 21 01:21:39 2014 +0400

    ENET_IPV6 flag

commit db8fb8c
Author: proller <proller@github.com>
Date:   Wed May 21 00:25:51 2014 +0400

    Try to add windows tcpip headers

commit 28c5f1e
Merge: 3963c69 06b535c
Author: proller <proller@github.com>
Date:   Mon May 12 01:00:21 2014 +0400

    Merge branch 'master' into ipv6

commit 3963c69
Merge: 3586b8a 47c8379
Author: proller <proller@github.com>
Date:   Mon May 12 00:56:06 2014 +0400

    Merge remote-tracking branch 'origin/master' into ipv6

commit 3586b8a
Author: proller <proller@github.com>
Date:   Thu Apr 10 23:50:10 2014 +0400

    win32 convert, unfinished

commit 3d27904
Author: proller <proller@github.com>
Date:   Thu Apr 10 23:20:32 2014 +0400

    ipv6 support

commit 54d2681
Author: proller <proller@github.com>
Date:   Thu Apr 10 22:56:28 2014 +0400

    add CMakeLists.txt

Author: proller

host.c

@@ -49,6 +49,8 @@ enet_host_create (const ENetAddress * address, size_t peerCount, size_t channelL
     memset (host -> peers, 0, peerCount * sizeof (ENetPeer));
 
     host -> socket = enet_socket_create (ENET_SOCKET_TYPE_DATAGRAM);
+    if (host -> socket != ENET_SOCKET_NULL)
+       enet_socket_set_option (host -> socket, ENET_SOCKOPT_IPV6_V6ONLY, 0);
     if (host -> socket == ENET_SOCKET_NULL || (address != NULL && enet_socket_bind (host -> socket, address) < 0))
     {
        if (host -> socket != ENET_SOCKET_NULL)
@@ -64,6 +66,8 @@ enet_host_create (const ENetAddress * address, size_t peerCount, size_t channelL
     enet_socket_set_option (host -> socket, ENET_SOCKOPT_BROADCAST, 1);
     enet_socket_set_option (host -> socket, ENET_SOCKOPT_RCVBUF, ENET_HOST_RECEIVE_BUFFER_SIZE);
     enet_socket_set_option (host -> socket, ENET_SOCKOPT_SNDBUF, ENET_HOST_SEND_BUFFER_SIZE);
+    enet_socket_set_option (host -> socket, ENET_SOCKOPT_IPV6_V6ONLY, 0);
+
 
     if (address != NULL && enet_socket_get_address (host -> socket, & host -> address) < 0)   
       host -> address = * address;
@@ -87,7 +91,7 @@ enet_host_create (const ENetAddress * address, size_t peerCount, size_t channelL
     host -> commandCount = 0;
     host -> bufferCount = 0;
     host -> checksum = NULL;
-    host -> receivedAddress.host = ENET_HOST_ANY;
+    host -> receivedAddress.host = in6addr_any;
     host -> receivedAddress.port = 0;
     host -> receivedData = NULL;
     host -> receivedDataLength = 0;

include/enet/enet.h

@@ -62,7 +62,8 @@ typedef enum _ENetSocketOption
    ENET_SOCKOPT_RCVTIMEO  = 6,
    ENET_SOCKOPT_SNDTIMEO  = 7,
    ENET_SOCKOPT_ERROR     = 8,
-   ENET_SOCKOPT_NODELAY   = 9
+   ENET_SOCKOPT_NODELAY   = 9,
+   ENET_SOCKOPT_IPV6_V6ONLY = 10
 } ENetSocketOption;
 
 typedef enum _ENetSocketShutdown
@@ -72,6 +73,7 @@ typedef enum _ENetSocketShutdown
     ENET_SOCKET_SHUTDOWN_READ_WRITE = 2
 } ENetSocketShutdown;
 
+#define ENET_IPV6           1
 #define ENET_HOST_ANY       0
 #define ENET_HOST_BROADCAST 0xFFFFFFFFU
 #define ENET_PORT_ANY       0
@@ -88,10 +90,13 @@ typedef enum _ENetSocketShutdown
  */
 typedef struct _ENetAddress
 {
-   enet_uint32 host;
+   struct in6_addr host;
    enet_uint16 port;
+   enet_uint16 sin6_scope_id;
 } ENetAddress;
 
+#define in6_equal(in6_addr_a, in6_addr_b) (memcmp(&in6_addr_a, &in6_addr_b, sizeof(struct in6_addr)) == 0)
+
 /**
  * Packet flag bit constants.
  *

include/enet/win32.h

@@ -14,9 +14,20 @@
 #endif
 #endif
 
+
+#ifndef WIN32_LEAN_AND_MEAN
+	#define WIN32_LEAN_AND_MEAN
+#endif
+#ifndef _WIN32_WINNT
+	#define _WIN32_WINNT 0x0501
+#endif
+#ifndef NOMINMAX
+	#define NOMINMAX
+#endif
 #include <stdlib.h>
 #include <winsock2.h>
 #include <windows.h>
+#include <ws2tcpip.h>
 
 typedef SOCKET ENetSocket;
 

protocol.c

@@ -298,7 +298,7 @@ enet_protocol_handle_connect (ENetHost * host, ENetProtocolHeader * header, ENet
         }
         else 
         if (currentPeer -> state != ENET_PEER_STATE_CONNECTING &&
-            currentPeer -> address.host == host -> receivedAddress.host)
+            in6_equal(currentPeer -> address.host , host -> receivedAddress.host))
         {
             if (currentPeer -> address.port == host -> receivedAddress.port &&
                 currentPeer -> connectID == command -> connect.connectID)
@@ -1010,9 +1010,9 @@ enet_protocol_handle_incoming_commands (ENetHost * host, ENetEvent * event)
 
        if (peer -> state == ENET_PEER_STATE_DISCONNECTED ||
            peer -> state == ENET_PEER_STATE_ZOMBIE ||
-           ((host -> receivedAddress.host != peer -> address.host ||
+           ((!in6_equal(host -> receivedAddress.host , peer -> address.host) ||
              host -> receivedAddress.port != peer -> address.port) &&
-             peer -> address.host != ENET_HOST_BROADCAST) ||
+             1 /* no broadcast in ipv6  !in6_equal(peer -> address.host , ENET_HOST_BROADCAST)*/) ||
            (peer -> outgoingPeerID < ENET_PROTOCOL_MAXIMUM_PEER_ID &&
             sessionID != peer -> incomingSessionID))
          return 0;