From e52d6a07b70e9e154f45914c1df6df088b92c49a Mon Sep 17 00:00:00 2001
From: csoler <retroshare.project@gmail.com>
Date: Sun, 15 Mar 2015 15:30:55 +0000
Subject: [PATCH] 0005 conversions from IPv4/IPv6 (Patch from G10H4ck)

git-svn-id: http://svn.code.sf.net/p/retroshare/code/branches/v0.6-IPv6@8029 b45a01b8-16f6-495d-af2f-9b41ad6348cc
---
 libretroshare/src/util/rsnet.h     |  1 +
 libretroshare/src/util/rsnet_ss.cc | 37 ++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/libretroshare/src/util/rsnet.h b/libretroshare/src/util/rsnet.h
index 74f4877ae..e258961e7 100644
--- a/libretroshare/src/util/rsnet.h
+++ b/libretroshare/src/util/rsnet.h
@@ -96,6 +96,7 @@ bool sockaddr_storage_inet_pton(struct sockaddr_storage &addr, const char * ip_s
 bool sockaddr_storage_ipv4_setport(struct sockaddr_storage &addr, const uint16_t port);
 
 bool sockaddr_storage_ipv4_to_ipv6(sockaddr_storage &addr);
+bool sockaddr_storage_ipv6_to_ipv4(sockaddr_storage &addr);
 
 // comparisons.
 bool operator<(const struct sockaddr_storage &a, const struct sockaddr_storage &b);
diff --git a/libretroshare/src/util/rsnet_ss.cc b/libretroshare/src/util/rsnet_ss.cc
index 608922294..6510f5505 100644
--- a/libretroshare/src/util/rsnet_ss.cc
+++ b/libretroshare/src/util/rsnet_ss.cc
@@ -280,7 +280,9 @@ bool sockaddr_storage_inet_pton(struct sockaddr_storage &addr, const char * ip_s
 
 bool sockaddr_storage_ipv4_to_ipv6(sockaddr_storage &addr)
 {
+#ifdef SS_DEBUG
 	std::cerr << "sockaddr_storage_ipv4_to_ipv6(sockaddr_storage &addr)" << std::endl;
+#endif
 
 	if ( addr.ss_family == AF_INET6 ) return true;
 
@@ -304,6 +306,41 @@ bool sockaddr_storage_ipv4_to_ipv6(sockaddr_storage &addr)
 	return false;
 }
 
+bool sockaddr_storage_ipv6_to_ipv4(sockaddr_storage &addr)
+{
+//#ifdef SS_DEBUG
+	std::cerr << "sockaddr_storage_ipv6_to_ipv4(sockaddr_storage &addr)" << std::endl;
+//#endif
+
+	if ( addr.ss_family == AF_INET ) return true;
+
+	if ( addr.ss_family == AF_INET6 )
+	{
+		sockaddr_in6 & addr_ipv6 =  (sockaddr_in6 &) addr;
+		bool ipv4m = addr_ipv6.sin6_addr.s6_addr16[5] == (u_int16_t) 0xffff;
+		for ( int i = 0; ipv4m && i < 5 ; ++i )
+			ipv4m &= addr_ipv6.sin6_addr.s6_addr16[i] == (u_int16_t) 0x0000;
+
+		if(ipv4m)
+		{
+			u_int32_t ip = addr_ipv6.sin6_addr.s6_addr32[3];
+			u_int16_t port = addr_ipv6.sin6_port;
+
+			sockaddr_in & addr_ipv4 = (sockaddr_in &) addr;
+
+			sockaddr_storage_clear(addr);
+			addr_ipv4.sin_family = AF_INET;
+			addr_ipv4.sin_port = port;
+			addr_ipv4.sin_addr.s_addr = ip;
+
+			return true;
+		}
+	}
+
+	return false;
+}
+
+
 /******************************** Comparisions **********************************/
 
 bool operator<(const struct sockaddr_storage &a, const struct sockaddr_storage &b)