Add "-N" option to supress reverse name lookup.

This comes in really handy when you're telneting the broken DNS server by
IP.

PR:		bin/8698

5 files changed, 12 insertions, 3 deletions

diff --git a/usr.bin/telnet/commands.c b/usr.bin/telnet/commands.c
index 165bec2..ebacc42 100644
--- a/usr.bin/telnet/commands.c
+++ b/usr.bin/telnet/commands.c
@@ -2186,7 +2186,8 @@ tn(argc, argv)
 	if (temp != INADDR_NONE) {
 	    sin.sin_addr.s_addr = temp;
 	    sin.sin_family = AF_INET;
-	    host = gethostbyaddr((char *)&temp, sizeof(temp), AF_INET);
+	    if (doaddrlookup)
+		host = gethostbyaddr((char *)&temp, sizeof(temp), AF_INET);
 	    if (host)
 	        (void) strncpy(_hostname, host->h_name, sizeof(_hostname));
 	    else
diff --git a/usr.bin/telnet/externs.h b/usr.bin/telnet/externs.h
index 43fdb43..a8c3f24 100644
--- a/usr.bin/telnet/externs.h
+++ b/usr.bin/telnet/externs.h
@@ -145,6 +145,7 @@ extern int
     termdata,		/* Print out terminal data flow */
 #endif	/* defined(unix) */
     debug,		/* Debug level */
+    doaddrlookup,	/* do a reverse lookup? */
     clienteof;		/* Client received EOF */
 
 extern cc_t escape;	/* Escape to command mode */
diff --git a/usr.bin/telnet/main.c b/usr.bin/telnet/main.c
index 3c4d8df..7f7c9ff 100644
--- a/usr.bin/telnet/main.c
+++ b/usr.bin/telnet/main.c
@@ -135,7 +135,7 @@ main(argc, argv)
 	rlogin = (strncmp(prompt, "rlog", 4) == 0) ? '~' : _POSIX_VDISABLE;
 	autologin = -1;
 
-	while ((ch = getopt(argc, argv, "8EKLS:X:acde:fFk:l:n:rt:x")) != -1) {
+	while ((ch = getopt(argc, argv, "8EKLNS:X:acde:fFk:l:n:rt:x")) != -1) {
 		switch(ch) {
 		case '8':
 			eight = 3;	/* binary output and input */
@@ -151,6 +151,9 @@ main(argc, argv)
 		case 'L':
 			eight |= 2;	/* binary output only */
 			break;
+		case 'N':
+			doaddrlookup = 0;
+			break;
 		case 'S':
 		    {
 #ifdef	HAS_GETTOS
diff --git a/usr.bin/telnet/telnet.1 b/usr.bin/telnet/telnet.1
index b234919..de161e8 100644
--- a/usr.bin/telnet/telnet.1
+++ b/usr.bin/telnet/telnet.1
@@ -30,7 +30,7 @@
 .\" SUCH DAMAGE.
 .\"
 .\"	@(#)telnet.1	8.5 (Berkeley) 3/1/94
-.\"	$Id: telnet.1,v 1.8 1997/11/11 05:00:59 steve Exp $
+.\"	$Id: telnet.1,v 1.9 1997/12/27 18:58:27 steve Exp $
 .\"
 .Dd March 1, 1994
 .Dt TELNET 1
@@ -93,6 +93,9 @@ Specifies no automatic login to the remote system.
 Specifies an 8-bit data path on output.  This causes the
 .Dv BINARY
 option to be negotiated on output.
+.It Fl N
+Prevents IP address to name lookup when destination host is given
+as an IP address.
 .It Fl S Ar tos
 Sets the IP type-of-service (TOS) option for the telnet
 connection to the value
diff --git a/usr.bin/telnet/telnet.c b/usr.bin/telnet/telnet.c
index 5057969..da8b0e1 100644
--- a/usr.bin/telnet/telnet.c
+++ b/usr.bin/telnet/telnet.c
@@ -106,6 +106,7 @@ int
 	donebinarytoggle,	/* the user has put us in binary */
 	dontlecho,	/* do we suppress local echoing right now? */
 	globalmode,
+	doaddrlookup = 1, /* do a reverse address lookup? */
 	clienteof = 0;
 
 char *prompt = 0;