Safety wrapper defines for ipv6 code on ipv4 ircds

git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@4697 e03df62e-2008-0410-955e-edbf42e46eb7

3 files changed, 33 insertions, 18 deletions

diff --git a/configure b/configure
index a46a22e9e..e44f3a595 100755
--- a/configure
+++ b/configure
@@ -38,8 +38,9 @@ $config{HAS_STDINT}         = "false";						# stdint.h check
 $config{HAS_EXECINFO}       = "0";						# execinfo.h Check.
 $config{USE_KQUEUE}         = "y";						# kqueue enabled
 $config{USE_EPOLL}          = "y";						# epoll enabled
-$config{THREADED_DNS}       = "n";						# threaded dns (experimental)
+$config{THREADED_DNS}       = "n";						# threaded dns
 $config{IPV6}               = "n";						# IPv6 support (experimental)
+$config{SUPPORT_IP6LINKS}   = "y";						# IPv4 supporting IPv6 links (experimental)
 $config{STATIC_LINK}	    = "no";						# are doing static modules?
 chomp($config{MAX_CLIENT_T} = `sh -c \"ulimit -n\"`);           		# FD Limit
 chomp($config{MAX_DESCRIPTORS} = `sh -c \"ulimit -n\"`);			# Hard FD Limit
@@ -360,9 +361,17 @@ if (!$chose_hiperf) {
 	print "not to enable one. Defaulting to select() engine.\n\n";
 }
 
-yesno(IPV6,"Would you like to enable experimental IPv6 support?");
+yesno(IPV6,"Would you like to build InspIRCd with IPv6 support?");
 print "\n";
 
+if ($config{IPV6} eq "y") {
+	print "You have chosen to build an \033[1;32mIPV6-only\033[0m server.\nTo accept IPV4 users, you must use the '::ffff:' notation of addresses.\n\n";
+	$config{SUPPORT_IP6LINKS} = "y";
+} else {
+	yesno(SUPPORT_IP6LINKS,"You have chosen to build an \033[1;32mIPV4-only\033[0m server.\nWould you like to enable support for linking to IPV6-enabled\nInspIRCd servers which are using '::ffff:' notation?\nIf you are using a recent operating\nsystem and are unsure, answer yes.");
+	print "\n";
+}
+
 if (($config{HAS_GNUTLS} eq "y") && ($config{HAS_OPENSSL} eq "y")) {
 	print "I have detected both GnuTLS and OpenSSL on your system.\n";
 	print "I will default to GnuTLS. If you wish to use OpenSSL\n";
@@ -673,6 +682,7 @@ print "\033[0mCompiler program:\033[1;32m\t\t$config{CC}\033[0m\n";
 print "\033[0mStatic modules:\033[1;32m\t\t\t$config{STATIC_LINK}\033[0m\n";
 print "\033[0mMultithread DNS:\033[1;32m\t\t$config{THREADED_DNS}\033[0m\n";
 print "\033[0mIPv6 Support:\033[1;32m\t\t\t$config{IPV6}\033[0m\n";
+print "\033[0mIPv6 to IPv4 Links:\033[1;32m\t\t\$config{SUPPORT_IP6LINKS}\033[0m\n";
 print "\033[0mGnuTLS Support:\033[1;32m\t\t\t$config{USE_GNUTLS}\033[0m\n";
 print "\033[0mOpenSSL Support:\033[1;32m\t\t$config{USE_OPENSSL}\033[0m\n\n";
 
@@ -1013,9 +1023,12 @@ EOF
 		if ($config{THREADED_DNS} =~ /y/i) {
 			print FILEHANDLE "#define THREADED_DNS\n";
 		}
-		if ($config{IPV6} =~/y/i) {
+		if ($config{IPV6} =~ /y/i) {
 			print FILEHANDLE "#define IPV6\n";
 		}
+		if ($config{SUPPORT_IP6LINKS} =~ /y/i) {
+			print FILEHANDLE "#define SUPPORT_IP6LINKS\n";
+		}
 		my $use_hiperf = 0;
 		if (($has_kqueue) && ($config{USE_KQUEUE} eq "y")) {
 			print FILEHANDLE "#define USE_KQUEUE\n";
diff --git a/src/dns.cpp b/src/dns.cpp
index 42db21424..0a22b28d8 100644
--- a/src/dns.cpp
+++ b/src/dns.cpp
@@ -453,7 +453,7 @@ int DNS::GetNameForce(const char *ip, ForceProtocol fp)
 	DNSHeader h;
 	int id;
 	int length;
-
+#ifdef SUPPORT_IP6LINKS
 	if (fp == PROTOCOL_IPV6)
 	{
 		in6_addr i;
@@ -466,6 +466,7 @@ int DNS::GetNameForce(const char *ip, ForceProtocol fp)
 			return -1;
 	}
 	else
+#endif
 	{
 		in_addr i;
 		if (inet_aton(ip, &i))
@@ -493,6 +494,7 @@ int DNS::GetNameForce(const char *ip, ForceProtocol fp)
 
 void DNS::MakeIP6Int(char* query, const in6_addr *ip)
 {
+#ifdef SUPPORT_IP6LINKS
 	const char* hex = "0123456789abcdef";
 	for (int index = 31; index >= 0; index--) /* for() loop steps twice per byte */
 	{
@@ -505,6 +507,9 @@ void DNS::MakeIP6Int(char* query, const in6_addr *ip)
 		*query++ = '.'; /* Seperator */
 	}
 	strcpy(query,"ip6.arpa"); /* Suffix the string */
+#else
+	*query = 0;
+#endif
 }
 
 /* Return the next id which is ready, and the result attached to it */
diff --git a/src/users.cpp b/src/users.cpp
index 85d64d462..74f70b458 100644
--- a/src/users.cpp
+++ b/src/users.cpp
@@ -895,20 +895,11 @@ long FindMatchingGlobal(userrec* user)
 	long x = 0;
 	for (user_hash::const_iterator a = clientlist.begin(); a != clientlist.end(); a++)
 	{
-#ifdef IPV6
-		/* I dont think theres any faster way of matching two ipv6 addresses than memcmp
-		 * Let me know if you think of one.
-		  */
-		in6_addr* s1 = &(((sockaddr_in6*)&a->second->ip)->sin6_addr);
-		in6_addr* s2 = &(((sockaddr_in6*)&user->ip)->sin6_addr);
-		if (!memcmp(s1->s6_addr, s2->s6_addr, sizeof(in6_addr)))
-			x++;
-#else
-		in_addr* s1 = &((sockaddr_in*)&a->second->ip)->sin_addr;
-		in_addr* s2 = &((sockaddr_in*)&user->ip)->sin_addr;
-		if (s1->s_addr == s2->s_addr)
-			x++;
-#endif
+		/* We have to match ip's as strings - we don't know what protocol
+		 * a remote user may be using
+		 */
+		if (!strcasecmp(a->second->GetIPString(), user->GetIPString()))
+				x++;
 	}
 	return x;
 }
@@ -1111,6 +1102,7 @@ void userrec::SetSockAddr(int protocol_family, const char* ip, int port)
 {
 	switch (protocol_family)
 	{
+#ifdef SUPPORT_IP6LINKS
 		case AF_INET6:
 		{
 			sockaddr_in6* sin = (sockaddr_in6*)&this->ip;
@@ -1119,6 +1111,7 @@ void userrec::SetSockAddr(int protocol_family, const char* ip, int port)
 			inet_pton(AF_INET6, ip, &sin->sin6_addr);
 		}
 		break;
+#endif
 		case AF_INET:
 		{
 			sockaddr_in* sin = (sockaddr_in*)&this->ip;
@@ -1137,12 +1130,14 @@ int userrec::GetPort()
 {
 	switch (this->GetProtocolFamily())
 	{
+#ifdef SUPPORT_IP6LINKS
 		case AF_INET6:
 		{
 			sockaddr_in6* sin = (sockaddr_in6*)&this->ip;
 			return sin->sin6_port;
 		}
 		break;
+#endif
 		case AF_INET:
 		{
 			sockaddr_in* sin = (sockaddr_in*)&this->ip;
@@ -1168,6 +1163,7 @@ const char* userrec::GetIPString()
 
 	switch (this->GetProtocolFamily())
 	{
+#ifdef SUPPORT_IP6LINKS
 		case AF_INET6:
 		{
 			sockaddr_in6* sin = (sockaddr_in6*)&this->ip;
@@ -1175,6 +1171,7 @@ const char* userrec::GetIPString()
 			return buf;
 		}
 		break;
+#endif
 		case AF_INET:
 		{
 			sockaddr_in* sin = (sockaddr_in*)&this->ip;