diff -up screen/src/doc/screen.1.ipv6 screen/src/doc/screen.1

--- screen/src/doc/screen.1.ipv6	2010-11-11 03:47:46.000000000 +0100

+++ screen/src/doc/screen.1	2011-02-03 16:05:35.957087079 +0100

@@ -398,6 +398,12 @@ Send the specified command to a running 

 the \fB-d\fP or \fB-r\fP option to tell screen to look only for

 attached or detached screen sessions. Note that this command doesn't

 work if the session is password protected.

+.TP 5

+.B \-4

+Resolve hostnames only to IPv4 addresses.

+.TP 5

+.B \-6

+Resolve hostnames only to IPv6 addresses.

 .SH "DEFAULT KEY BINDINGS"

 .ta 12n 26n

diff -up screen/src/extern.h.ipv6 screen/src/extern.h

--- screen/src/extern.h.ipv6	2010-11-11 03:47:46.000000000 +0100

+++ screen/src/extern.h	2011-02-03 16:04:35.995743620 +0100

@@ -455,8 +455,7 @@ extern void  ExitOverlayPage __P((void))

 /* teln.c */

 #ifdef BUILTIN_TELNET

-extern int   TelOpen __P((char **));

-extern int   TelConnect __P((struct win *));

+extern int   TelOpenAndConnect __P((struct win *));

 extern int   TelIsline __P((struct win *p));

 extern void  TelProcessLine __P((char **, int *));

 extern int   DoTelnet __P((char *, int *, int));

diff -up screen/src/help.c.ipv6 screen/src/help.c

--- screen/src/help.c.ipv6	2010-11-11 03:47:46.000000000 +0100

+++ screen/src/help.c	2011-02-03 16:04:35.992744154 +0100

@@ -66,6 +66,10 @@ char *myname, *message, *arg;

 {

   printf("Use: %s [-opts] [cmd [args]]\n", myname);

   printf(" or: %s -r [host.tty]\n\nOptions:\n", myname);

+#ifdef BUILTIN_TELNET

+  printf("-4            Resolve hostnames only to IPv4 addresses.\n");

+  printf("-6            Resolve hostnames only to IPv6 addresses.\n");

+#endif

   printf("-a            Force all capabilities into each window's termcap.\n");

   printf("-A -[r|R]     Adapt all windows to the new display width & height.\n");

   printf("-c file       Read configuration file instead of '.screenrc'.\n");

diff -up screen/src/screen.c.ipv6 screen/src/screen.c

--- screen/src/screen.c.ipv6	2010-11-11 03:47:46.000000000 +0100

+++ screen/src/screen.c	2011-02-03 16:04:35.994743798 +0100

@@ -248,8 +248,9 @@ struct layer *flayer;

 struct win *fore;

 struct win *windows;

 struct win *console_window;

-

-

+#ifdef BUILTIN_TELNET

+int af;

+#endif

 /*

  * Do this last

@@ -507,6 +508,9 @@ char **av;

   nwin = nwin_undef;

   nwin_options = nwin_undef;

   strcpy(screenterm, "screen");

+#ifdef BUILTIN_TELNET

+  af = AF_UNSPEC;

+#endif

   logreopen_register(lf_secreopen);

@@ -541,6 +545,14 @@ char **av;

 	    {

 	      switch (*ap)

 		{

+#ifdef BUILTIN_TELNET

+               case '4':

+                 af = AF_INET;

+                 break;

+               case '6':

+                 af = AF_INET6;

+                 break;

+#endif

 		case 'a':

 		  nwin_options.aflag = 1;

 		  break;

diff -up screen/src/teln.c.ipv6 screen/src/teln.c

--- screen/src/teln.c.ipv6	2010-11-11 03:47:46.000000000 +0100

+++ screen/src/teln.c	2011-02-03 16:04:35.992744154 +0100

@@ -30,6 +30,7 @@

 #include <sys/socket.h>

 #include <fcntl.h>

 #include <netdb.h>

+#include <stdio.h>

 #include "config.h"

@@ -42,12 +43,13 @@ extern struct win *fore;

 extern struct layer *flayer;

 extern int visual_bell;

 extern char screenterm[];

+extern int af;

 static void TelReply __P((struct win *, char *, int));

 static void TelDocmd __P((struct win *, int, int));

 static void TelDosub __P((struct win *));

-

-#define TEL_DEFPORT	23

+// why TEL_DEFPORT has "

+#define TEL_DEFPORT	"23"

 #define TEL_CONNECTING	(-2)

 #define TC_IAC          255

@@ -105,86 +107,78 @@ char *data;

 }

 int

-TelOpen(args)

-char **args;

-{

-  int fd;

-  int on = 1;

-

-  if ((fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)

-    {

-      Msg(errno, "TelOpen: socket");

-      return -1;

-    }

-  if (setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, (char *)&on, sizeof(on)))

-    Msg(errno, "TelOpen: setsockopt SO_OOBINLINE");

-  return fd;

-}

-

-int

-TelConnect(p)

-struct win *p;

-{

-  int port = TEL_DEFPORT;

-  struct hostent *hp;

-  char **args;

+TelOpenAndConnect(struct win *p) {

+  int fd, on = 1;

   char buf[256];

-  args = p->w_cmdargs + 1;

-

-  if (!*args)

-    {

-      Msg(0, "Usage: screen //telnet host [port]");

-      return -1;

-    }

-  if (args[1])

-    port = atoi(args[1]);

-  p->w_telsa.sin_family = AF_INET;

-  if((p->w_telsa.sin_addr.s_addr = inet_addr(*args)) == -1)

-    {

-      if ((hp = gethostbyname(*args)) == NULL)

-        {

-	  Msg(0, "unknown host: %s", *args);

-	  return -1;

-        }

-      if (hp->h_length != sizeof(p->w_telsa.sin_addr.s_addr) || hp->h_addrtype != AF_INET)

-	{

-	  Msg(0, "Bad address type for %s", hp->h_name);

-	  return -1;

-	}

-      bcopy((char *)hp->h_addr,(char *)&p->w_telsa.sin_addr.s_addr, hp->h_length);

-      p->w_telsa.sin_family = hp->h_addrtype;

-    }

-  p->w_telsa.sin_port = htons(port);

-  if (port != TEL_DEFPORT)

-    sprintf(buf, "Trying %s %d...", inet_ntoa(p->w_telsa.sin_addr), port);

-  else

-    sprintf(buf, "Trying %s...", inet_ntoa(p->w_telsa.sin_addr));

-  WriteString(p, buf, strlen(buf));

-  if (connect(p->w_ptyfd, (struct sockaddr *)&p->w_telsa, sizeof(p->w_telsa)))

-    {

-      if (errno == EINPROGRESS)

-        {

-	  p->w_telstate = TEL_CONNECTING;

-	  p->w_telconnev.fd = p->w_ptyfd;

-	  p->w_telconnev.handler = tel_connev_fn;

-	  p->w_telconnev.data = (char *)p;

-	  p->w_telconnev.type = EV_WRITE;

-	  p->w_telconnev.pri = 1;

-	  debug("telnet connect in progress...\n");

-	  evenq(&p->w_telconnev);

-	}

-      else

-        {

-	  Msg(errno, "TelOpen: connect");

-	  return -1;

-	}

-    }

-  else

-    WriteString(p, "connected.\r\n", 12);

-  if (port == TEL_DEFPORT)

-    TelReply(p, (char *)tn_init, sizeof(tn_init));

-  return 0;

+  struct addrinfo hints, *res0, *res;

+

+  if (!(p->w_cmdargs[1])) {

+    Msg(0, "Usage: screen //telnet host [port]");

+    return -1;

+  }

+

+  memset(&hints, 0, sizeof(hints));

+  hints.ai_family = af;

+  hints.ai_socktype = SOCK_STREAM;

+  hints.ai_protocol = IPPROTO_TCP;

+  if(getaddrinfo(p->w_cmdargs[1], p->w_cmdargs[2] ? p->w_cmdargs[2] : TEL_DEFPORT,

+                 &hints, &res0)) {

+     Msg(0, "unknown host: %s", p->w_cmdargs[1]);

+     return -1;

+  }

+

+  for(res = res0; res; res = res->ai_next) {

+    if((fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) == -1) {

+      if(res->ai_next)

+        continue;

+      else {

+        Msg(errno, "TelOpenAndConnect: socket");

+        freeaddrinfo(res0);

+        return -1;

+      }

+    }

+

+    if (setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, (char *)&on, sizeof(on)))

+      Msg(errno, "TelOpenAndConnect: setsockopt SO_OOBINLINE");

+

+    if (p->w_cmdargs[2] && strcmp(p->w_cmdargs[2], TEL_DEFPORT))

+      snprintf(buf, 256, "Trying %s %s...", p->w_cmdargs[1], p->w_cmdargs[2]);

+    else

+      snprintf(buf, 256, "Trying %s...", p->w_cmdargs[1]);

+    WriteString(p, buf, strlen(buf));

+    if (connect(fd, res->ai_addr, res->ai_addrlen)) {

+      if (errno == EINPROGRESS) {

+       p->w_telstate = TEL_CONNECTING;

+       p->w_telconnev.fd = fd;

+       p->w_telconnev.handler = tel_connev_fn;

+       p->w_telconnev.data = (char *)p;

+       p->w_telconnev.type = EV_WRITE;

+       p->w_telconnev.pri = 1;

+       debug("telnet connect in progress...\n");

+       evenq(&p->w_telconnev);

+      }

+      else {

+        close(fd);

+       if(res->ai_next)

+         continue;

+       else {

+          Msg(errno, "TelOpenAndConnect: connect");

+          freeaddrinfo(res0);

+          return -1;

+       }

+      }

+    }

+    else

+      WriteString(p, "connected.\r\n", 12);

+    if (!(p->w_cmdargs[2] && strcmp(p->w_cmdargs[2], TEL_DEFPORT)))

+      TelReply(p, (char *)tn_init, sizeof(tn_init));

+    p->w_ptyfd = fd;

+    memcpy(&p->w_telsa, &res->ai_addr, sizeof(res->ai_addr));

+    freeaddrinfo(res0);

+    return 0;

+  }

+  return -1;

 }

 int

diff -up screen/src/window.c.ipv6 screen/src/window.c

--- screen/src/window.c.ipv6	2010-11-11 03:47:46.000000000 +0100

+++ screen/src/window.c	2011-02-03 16:30:56.900750293 +0100

@@ -605,6 +605,13 @@ struct NewWindow *newwin;

   n = pp - wtab;

   debug1("Makewin creating %d\n", n);

+#ifdef BUILTIN_TELNET

+  if(!strcmp(nwin.args[0], "//telnet")) {

+         type = W_TYPE_TELNET;

+         TtyName = "telnet";

+  }

+  else

+#endif

   if ((f = OpenDevice(nwin.args, nwin.lflag, &type, &TtyName)) < 0)

     return -1;

   if (type == W_TYPE_GROUP)

@@ -766,7 +773,7 @@ struct NewWindow *newwin;

 #ifdef BUILTIN_TELNET

   if (type == W_TYPE_TELNET)

     {

-      if (TelConnect(p))

+      if (TelOpenAndConnect(p))

 	{

 	  FreeWindow(p);

 	  return -1;

@@ -878,6 +885,13 @@ struct win *p;

   int lflag, f;

   lflag = nwin_default.lflag;

+#ifdef BUILTIN_TELNET

+  if(!strcmp(p->w_cmdargs[0], "//telnet")) {

+         p->w_type = W_TYPE_TELNET;

+         TtyName = "telnet";

+  }

+  else

+#endif

   if ((f = OpenDevice(p->w_cmdargs, lflag, &p->w_type, &TtyName)) < 0)

     return -1;

@@ -909,7 +923,7 @@ struct win *p;

 #ifdef BUILTIN_TELNET

   if (p->w_type == W_TYPE_TELNET)

     {

-      if (TelConnect(p))

+      if (TelOpenAndConnect(p))

         return -1;

     }

   else

@@ -1068,16 +1082,6 @@ char **namep;

       *namep = "telnet";

       return 0;

     }

-#ifdef BUILTIN_TELNET

-  if (strcmp(arg, "//telnet") == 0)

-    {

-      f = TelOpen(args + 1);

-      lflag = 0;

-      *typep = W_TYPE_TELNET;

-      *namep = "telnet";

-    }

-  else

-#endif

   if (strncmp(arg, "//", 2) == 0)

     {

       Msg(0, "Invalid argument '%s'", arg);

diff -up screen/src/window.h.ipv6 screen/src/window.h

--- screen/src/window.h.ipv6	2010-11-11 03:47:46.000000000 +0100

+++ screen/src/window.h	2011-02-03 16:04:35.989744687 +0100

@@ -268,7 +268,7 @@ struct win

   struct display *w_zdisplay;

 #endif

 #ifdef BUILTIN_TELNET

-  struct sockaddr_in w_telsa;

+  struct sockaddr_storage w_telsa;

   char   w_telbuf[IOSIZE];

   int    w_telbufl;

   char   w_telmopts[256];