diff -ruN netris-0.5/Configure netris-0.5-v6-19991206a/Configure
--- netris-0.5/Configure	Sun May 16 15:57:48 1999
+++ netris-0.5-v6-19991206a/Configure	Mon Dec  6 18:53:27 1999
@@ -57,6 +57,12 @@
 		--curses-hack)
 			CURSES_HACK=true
 			;;
+		--disable-ipv6|--enable-ipv6=no)
+			ENABLE_IPV6=no
+			;;
+		--enable-ipv6)
+			ENABLE_IPV6=yes
+			;;
 		*)
 			cat << "END"
 Usage: ./Configure [options...]
@@ -67,6 +73,7 @@
     --cextra <opt>: Set extra C flags
     --lextra <opt>: Set extra linker flags
     --curses-hack: Disable scroll-optimization for broken curses
+    --enable-ipv6: Enable IPv6 feature
 END
 			exit 1
 			;;
@@ -89,6 +96,7 @@
 	fi
 done
 
+
 echo "Checking for on_exit()"
 cat << END > test.c
 void handler(void) {}
@@ -135,6 +143,45 @@
 	HAS_MEMORY_H=false
 fi
 
+if test X"$ENABLE_IPV6" = X""; then
+	echo "Checking for whether we enable IPv6 feature"
+	cat << END >test.c
+#include <sys/types.h>
+#include <sys/socket.h>
+main(){
+ if (socket(AF_INET6, SOCK_STREAM, 0) < 0) return(1);
+ else return(0);
+}
+END
+	if $CC $CFLAGS $LEXTRA test.c > /dev/null 2>&1; then
+		if ./a.out 2>&1; then
+			ENABLE_IPV6=yes
+		else
+			ENABLE_IPV6=no
+		fi
+	fi
+fi
+if test X"$ENABLE_IPV6" = X"yes"; then
+	echo "Checking for IPv6 library"
+	CEXTRA="-DINET6 $CEXTRA"
+	IPV6_ENV="KAME V6 INET6"
+	IPV6_KAME_DIR=/usr/local/v6
+	IPV6_KAME_LIB=inet6
+	IPV6_V6_DIR=/usr/local/v6
+	IPV6_V6_DIB=v6
+	IPV6_INET6_DIR=/usr/inet6
+	IPV6_INET6_LIB=inet6
+	for i in $IPV6_ENV; do
+		eval IPV6_DIR=\$IPV6_${i}_DIR
+		eval IPV6_LIB=\$IPV6_${i}_LIB
+		if [ -f $IPV6_DIR/lib/lib${IPV6_LIB}.a ]; then
+			CEXTRA="-I$IPV6_DIR/include $CEXTRA"
+			LEXTRA="-L$IPV6_DIR/lib -l${IPV6_LIB} $LEXTRA"
+			break
+		fi
+	done
+fi
+
 rm -f test.c test.o a.out
 
 ORIG_SOURCES="game- curses- shapes- board- util- inet- robot-"
@@ -150,10 +197,14 @@
 echo > .depend
 
 echo "Creating Makefile"
-sed -e "s/-LFLAGS-/$LFLAGS/g" -e "s/-SRCS-/$SRCS/g" \
+_LFLAGS=`echo "$LFLAGS" | sed -e 's#/#\\\\/#g'`
+_LEXTRA=`echo "$LEXTRA" | sed -e 's#/#\\\\/#g'`
+_COPT=`echo "$COPT" | sed -e 's#/#\\\\/#g'`
+_CEXTRA=`echo "$CEXTRA" | sed -e 's#/#\\\\/#g'`
+sed -e "s/-LFLAGS-/$_LFLAGS/g" -e "s/-SRCS-/$SRCS/g" \
 	-e "s/-OBJS-/$OBJS/g" -e "s/-DISTFILES-/$DISTFILES/g" \
-	-e "s/-COPT-/$COPT/g" -e "s/-CEXTRA-/$CEXTRA/g" \
-	-e "s/-LEXTRA-/$LEXTRA/g" -e "s/-CC-/$CC/g" \
+	-e "s/-COPT-/$_COPT/g" -e "s/-CEXTRA-/$_CEXTRA/g" \
+	-e "s/-LEXTRA-/$_LEXTRA/g" -e "s/-CC-/$CC/g" \
 	<< "END" > Makefile
 #
 # Automatically generated by ./Configure -- DO NOT EDIT!
@@ -163,15 +214,19 @@
 COPT = -COPT-
 CEXTRA = -CEXTRA-
 LEXTRA = -LEXTRA-
-LFLAGS = -LEXTRA- -LFLAGS-
+LFLAGS = $(LEXTRA) -LFLAGS-
 CFLAGS = $(CEXTRA) $(COPT)
 
 PROG = netris
 HEADERS = netris.h
 
+PREFIX?=/usr/local
 SRCS = -SRCS-
 OBJS = -OBJS-
 DISTFILES = -DISTFILES-
+DESTDIR = $(PREFIX)/bin
+
+INSTALL = install -c
 
 all: Makefile config.h proto.h $(PROG) sr
 
@@ -228,6 +283,10 @@
 cleandir: clean
 	rm -f .depend Makefile config.h
 
+install:
+	$(INSTALL) -o bin -g bin -s -m 755 $(PROG) $(DESTDIR)
+	$(INSTALL) -o bin -g bin -s -m 755 sr $(DESTDIR)
+
 ##### DO NOT EDIT OR DELETE THIS LINE, it's needed by make depend #####
 END
 
@@ -256,6 +315,9 @@
 fi
 if [ "$CURSES_HACK" = "true" ]; then
 	echo "#define CURSES_HACK" >> config.h
+fi
+if [ "$ENABLE_IPV6" = "yes" ]; then
+	echo "#define ENABLE_IPV6" >> config.h
 fi
 
 echo "Running 'make depend'"
diff -ruN netris-0.5/README.v6 netris-0.5-v6-19991206a/README.v6
--- netris-0.5/README.v6	Thu Jan  1 09:00:00 1970
+++ netris-0.5-v6-19991206a/README.v6	Mon Dec  6 19:23:23 1999
@@ -0,0 +1,36 @@
+IPv6 Patch for netris-0.5
+
+IPv6 patch for netris is originally developped by H.YOSHIFUJi
+<yoshfuji@ecei.tohoku.ac.jp> in early December 1999.
+
+IPv6 support is enabled by defining INET6 macro during the 
+compilation phase.  "Configure" will detect and automatically
+enable this feature, but you can enable / disable this feature
+explicitly with "--enable-ipv6" / "--disable-ipv6" option to 
+the "Configure" scirpt.
+
+Note: INET6 switches netris into the protocol independent world, 
+      so you can enable this feature if you have getaddrinfo()
+      and getnameinfo() defined in RFC2553.
+
+Note: Netris cannot bind to multiple sockets without FD_ZERO
+      macro family.  In this case, it will bind to the first
+      socket it finds.  You can specify protocol family with
+      -4 / -6 option to the executable "netris" file.
+
+The following IPv6 platforms should be supported:
+	GNU/Linux with glibc-2.1.2
+	FreeBSD {2.2.8,3.3} with KAME package
+	Solaris 7 with IPv6_Prototype_01 package
+
+Note: On Solaris 7 + IPv6_Prototype_01 systems, you should 
+      register the port number in /etc/services file.
+      There is "ad hoc" solution, but I hate it because
+      it looks "dirty"; it discards the pure protocol 
+      independent socket programming model.
+
+** History **
+netris-0.5-v6-19991206		H.YOSHIFUJI <yoshfuji@ecei.tohoku.ac.jp>
+				- First patch.
+netric-0.5-v6-19991206a		H.YOSHIFUJI <yoshfuji@ecei.tohoku.ac.jp>
+				- fix core dump in strncpy().
diff -ruN netris-0.5/game.c netris-0.5-v6-19991206a/game.c
--- netris-0.5/game.c	Sun May 16 15:57:48 1999
+++ netris-0.5-v6-19991206a/game.c	Mon Dec  6 17:53:12 1999
@@ -25,6 +25,7 @@
 #include <ctype.h>
 #include <string.h>
 #include <sys/types.h>
+#include <sys/socket.h>
 #include <netinet/in.h>
 
 enum { KT_left, KT_rotate, KT_right, KT_drop, KT_down,
@@ -358,12 +359,36 @@
 {
 	int initConn = 0, waitConn = 0, ch;
 	char *hostStr = NULL, *portStr = NULL;
+#ifdef INET6
+	int default_ai_family = PF_UNSPEC;
+#endif
 
 	standoutEnable = colorEnable = 1;
 	stepDownInterval = DEFAULT_INTERVAL;
 	MapKeys(DEFAULT_KEYS);
-	while ((ch = getopt(argc, argv, "hHRs:r:Fk:c:woDSCp:i:")) != -1)
+	while ((ch = getopt(argc, argv, "hHRs:r:Fk:c:woDSCp:i:"
+#ifdef INET6
+#ifdef PF_INET6
+									"6"
+#endif
+#ifdef PF_INET
+									"4"
+#endif
+#endif
+			)) != -1)
 		switch (ch) {
+#ifdef INET6
+#ifdef PF_INET6
+			case '6':
+				default_ai_family = PF_INET6;
+				break;
+#endif
+#ifdef PF_INET
+			case '4':
+				default_ai_family = PF_INET;
+				break;
+#endif
+#endif
 			case 'c':
 				initConn = 1;
 				hostStr = optarg;
@@ -424,7 +449,11 @@
 	InitUtil();
 	if (robotEnable)
 		InitRobot(robotProg);
-	InitNet();
+#ifdef INET6
+	InitNet(default_ai_family);
+#else
+	InitNet(0);
+#endif
 	InitScreens();
 	if (initConn || waitConn) {
 		MyEvent event;
diff -ruN netris-0.5/inet.c netris-0.5-v6-19991206a/inet.c
--- netris-0.5/inet.c	Sun May 16 15:57:48 1999
+++ netris-0.5-v6-19991206a/inet.c	Mon Dec  6 19:19:29 1999
@@ -30,9 +30,16 @@
 #include <errno.h>
 
 #define HEADER_SIZE sizeof(netint2[2])
+#ifdef INET6
+# define MAX_LISTEN_SOCKS	16
+#endif
 
 static MyEventType NetGenFunc(EventGenRec *gen, MyEvent *event);
 
+#ifdef INET6
+static int Default_Ai_Family = PF_UNSPEC;
+static char str_buff[64 + NI_MAXHOST];
+#endif
 static int sock = -1;
 static EventGenRec netGen = { NULL, 0, FT_read, -1, NetGenFunc, EM_net };
 
@@ -40,25 +47,127 @@
 static int netBufSize, netBufGoal = HEADER_SIZE;
 static int isServer, lostConn, gotEndConn;
 
-ExtFunc void InitNet(void)
+ExtFunc void InitNet(int default_ai_family)
 {
+#ifdef INET6
+	Default_Ai_Family = default_ai_family;
+#endif
 	AtExit(CloseNet);
 }
 
 ExtFunc int WaitForConnection(char *portStr)
 {
+#ifdef INET6
+	struct sockaddr_storage addr;
+	struct addrinfo hints,*res0,*res;
+	int gai;
+	char serv_buf[NI_MAXSERV];
+#ifdef FD_ZERO
+	fd_set fdvar;
+#endif
+	int socklistListen[MAX_LISTEN_SOCKS];
+	int countSock, maxSock;
+	int i, sel;
+#else
 	struct sockaddr_in addr;
 	struct hostent *host;
+#endif
 	int sockListen;
 	int addrLen;
+#ifndef INET6
 	short port;
+#endif
 	int val1;
 	struct linger val2;
 
+#ifdef INET6
+	if (portStr)
+		strncpy(serv_buf, portStr, sizeof(serv_buf));
+	else
+		snprintf(serv_buf, sizeof(serv_buf), "%d", DEFAULT_PORT);
+#else
 	if (portStr)
 		port = atoi(portStr);	/* XXX Error checking */
 	else
 		port = DEFAULT_PORT;
+#endif
+#ifdef INET6
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = Default_Ai_Family;
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags = AI_PASSIVE;
+	gai = getaddrinfo(NULL, serv_buf, &hints, &res0);
+	if (gai){
+		snprintf(str_buff, sizeof(str_buff)-1, 
+				 "getaddrinfo(): %s", gai_strerror(gai));
+		str_buff[sizeof(str_buff)-1] = '\0';
+		fatal(str_buff);
+	}
+	countSock = 0;
+	maxSock = -1;
+#ifdef FD_ZERO
+	FD_ZERO(&fdvar);
+#endif
+	for (res=res0; res && (countSock < MAX_LISTEN_SOCKS); res=res->ai_next){
+		sockListen = socket(res->ai_family, res->ai_socktype, 0);
+		if(sockListen < 0) continue;
+		val1 = 1;
+		setsockopt(sockListen, SOL_SOCKET, SO_REUSEADDR,
+				   (void *)&val1, sizeof(val1));
+		if (bind(sockListen, res->ai_addr, res->ai_addrlen) < 0){
+			close(sockListen);
+			continue;
+		}
+		if (listen(sockListen, 1) < 0){
+			close(sockListen);
+			continue;
+		}
+#ifdef FD_ZERO
+		FD_SET(sockListen, &fdvar);
+#endif
+		socklistListen[countSock++] = sockListen;
+		if (maxSock < sockListen) maxSock = sockListen;
+#ifndef FD_ZERO
+#warn	You do not have FD_ZERO macro, so netris listens only one socket. This should be ok, but you might want to specify the protocol with -6 or -4 option.
+		if (countSock){
+			break;
+#endif
+	}
+	if (!countSock){
+		die("socket(),bind(),listen()");
+	}
+	freeaddrinfo(res0);
+#ifdef FD_ZERO
+	sockListen = -1;
+	while(sockListen < 0){
+		sel = select(maxSock + 1, &fdvar, NULL, NULL, NULL);
+		if (sel < 0){
+			for (i=0; i<countSock; i++){
+				close(socklistListen[i]);
+			}
+			die("select()");
+		}
+		for (i=0; i<countSock; i++){
+			if (FD_ISSET(socklistListen[i], &fdvar)){
+				sockListen = socklistListen[i];
+				break;
+			}
+		}
+		if (sockListen < 0)
+			sleep(1);
+	}
+#endif
+	addrLen = sizeof(addr);
+	sock = accept(sockListen, (struct sockaddr *)&addr, &addrLen);
+	for (i=0; i<countSock; i++){
+		close(socklistListen[i]);
+	}
+	if(sock<0){
+		close(sock);
+		die("accept()");
+	}
+	close(sockListen);
+#else
 	memset(&addr, 0, sizeof(addr));
 	addr.sin_family = AF_INET;
 	addr.sin_addr.s_addr = htonl(INADDR_ANY);
@@ -78,20 +187,31 @@
 	if (sock < 0)
 		die("accept");
 	close(sockListen);
+#endif
 	val2.l_onoff = 1;
 	val2.l_linger = 0;
 	setsockopt(sock, SOL_SOCKET, SO_LINGER,
 			(void *)&val2, sizeof(val2));
 	netGen.fd = sock;
-	strcpy(opponentHost, "???");
+	strncpy(opponentHost, "???", sizeof(opponentHost)-1);
+#ifdef INET6
+	if (getnameinfo((struct sockaddr *)&addr, addrLen,
+			opponentHost, sizeof(opponentHost)-1,
+			NULL, 0,
+			0)){
+	  close(sock);
+	  fatal("getnameinfo()");
+	}
+#else
 	if (addr.sin_family == AF_INET) {
 		host = gethostbyaddr((void *)&addr.sin_addr,
 				sizeof(struct in_addr), AF_INET);
-		if (host) {
+		if (host && host->h_name) {
 			strncpy(opponentHost, host->h_name, sizeof(opponentHost)-1);
-			opponentHost[sizeof(opponentHost)-1] = 0;
 		}
 	}
+#endif
+	opponentHost[sizeof(opponentHost)-1] = 0;
 	AddEventGen(&netGen);
 	isServer = 1;
 	return 0;
@@ -99,36 +219,96 @@
 
 ExtFunc int InitiateConnection(char *hostStr, char *portStr)
 {
+#ifdef INET6
+	struct sockaddr_storage;
+	struct addrinfo hints, *res0, *res;
+	char serv_buf[NI_MAXSERV];
+	int gai;
+#else
 	struct sockaddr_in addr;
 	struct hostent *host;
 	short port;
-	int mySock;
+#endif
+	int mySock = -1;
 
+#ifdef INET6
+	if (portStr)
+		strncpy(serv_buf, portStr, sizeof(serv_buf));
+	else
+		snprintf(serv_buf, sizeof(serv_buf), "%d",
+				 DEFAULT_PORT);
+#else
 	if (portStr)
 		port = atoi(portStr);	/* XXX Error checking */
 	else
 		port = DEFAULT_PORT;
+#endif
+#ifdef INET6
+	while (mySock < 0){
+		memset(&hints, 0, sizeof(hints));
+		hints.ai_family = Default_Ai_Family;
+		hints.ai_socktype = SOCK_STREAM;
+		hints.ai_flags = AI_CANONNAME;
+		gai = getaddrinfo(hostStr, serv_buf, &hints, &res0);
+    	if (gai){
+			snprintf(str_buff, sizeof(str_buff)-1, 
+					 "getaddrinfo(): %s", gai_strerror(gai));
+			str_buff[sizeof(str_buff)-1] = '\0';
+			fatal(str_buff);
+		}
+		for (res=res0; res; res=res->ai_next){
+			mySock = socket(res->ai_family, res->ai_socktype, 0);
+			if (mySock < 0)
+				continue;
+			if (connect(mySock, res->ai_addr, res->ai_addrlen) < 0){
+				close(mySock);
+				mySock = -1;
+				if(errno != ECONNREFUSED){
+					freeaddrinfo(res0);
+					die("connect");
+				}
+				else{
+					continue;
+				}
+			}
+			if (res->ai_canonname)
+				strncpy(opponentHost, res->ai_canonname, sizeof(opponentHost)-1);
+			else
+				strncpy(opponentHost, hostStr, sizeof(opponentHost)-1);
+			opponentHost[sizeof(opponentHost)-1] = 0;
+			break;
+		}
+		if (mySock < 0){
+			freeaddrinfo(res0);
+			sleep(1);
+			continue;
+		}
+	}
+#else
 	host = gethostbyname(hostStr);
 	if (!host)
 		die("gethostbyname");
 	assert(host->h_addrtype == AF_INET);
 	strncpy(opponentHost, host->h_name, sizeof(opponentHost)-1);
 	opponentHost[sizeof(opponentHost)-1] = 0;
- again:
-	memset(&addr, 0, sizeof(addr));
-	addr.sin_family = host->h_addrtype;
-	memcpy(&addr.sin_addr, host->h_addr, host->h_length);
-	addr.sin_port = htons(port);
-	mySock = socket(AF_INET, SOCK_STREAM, 0);
-	if (mySock < 0)
-		die("socket");
-	if (connect(mySock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
-		if (errno != ECONNREFUSED)
-			die("connect");
-		close(mySock);
-		sleep(1);
-		goto again;
+	while (1){
+		memset(&addr, 0, sizeof(addr));
+		addr.sin_family = host->h_addrtype;
+		memcpy(&addr.sin_addr, host->h_addr, host->h_length);
+		addr.sin_port = htons(port);
+		mySock = socket(AF_INET, SOCK_STREAM, 0);
+		if (mySock < 0)
+			die("socket");
+		if (connect(mySock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
+			if (errno != ECONNREFUSED)
+				die("connect");
+			close(mySock);
+			sleep(1);
+			continue;
+		}
+		break;
 	}
+#endif
 	netGen.fd = sock = mySock;
 	AddEventGen(&netGen);
 	return 0;
diff -ruN netris-0.5/util.c netris-0.5-v6-19991206a/util.c
--- netris-0.5/util.c	Sun May 16 15:57:48 1999
+++ netris-0.5-v6-19991206a/util.c	Mon Dec  6 18:33:30 1999
@@ -25,6 +25,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/types.h>
+#include <sys/socket.h>
 #include <sys/time.h>
 #include <netdb.h>
 #include <errno.h>
@@ -71,7 +72,19 @@
 	  "  -h		Print usage information\n"
 	  "  -w		Wait for connection\n"
 	  "  -c <host>	Initiate connection\n"
+#ifdef INET6
+	  "  -p <port>	Set port number / service name (default is %d)\n"
+#else
 	  "  -p <port>	Set port number (default is %d)\n"
+#endif
+#ifdef INET6
+#ifdef PF_INET6
+	  "  -6		Use only IPv6 socket\n"
+#endif
+#ifdef PF_INET
+	  "  -4		Use only IPv4 socket\n"
+#endif
+#endif
 	  "  -k <keys>	Remap keys.  The argument is a prefix of the string\n"
 	  "		  containing the keys in order: left, rotate, right, drop,\n"
 	  "		  down-faster, toggle-spying, pause, faster, redraw.\n"