--- netkit-telnet-0.17.orig/telnetd/telnetd.c.reallynodns	2009-03-12 14:32:29.000000000 -0700

+++ netkit-telnet-0.17.orig/telnetd/telnetd.c	2009-03-12 14:51:59.000000000 -0700

@@ -85,6 +85,7 @@

 int keepalive = 1;

 char *loginprg = _PATH_LOGIN;

 char *progname;

+int lookupself = 1;

 extern void usage(void);

@@ -111,7 +112,7 @@

 	progname = *argv;

-	while ((ch = getopt(argc, argv, "d:a:e:lhnr:I:D:B:sS:a:X:L:")) != EOF) {

+	while ((ch = getopt(argc, argv, "d:a:e:lhnr:I:D:B:sS:a:X:L:N")) != EOF) {

 		switch(ch) {

 #ifdef	AUTHENTICATE

@@ -210,6 +211,10 @@

 			keepalive = 0;

 			break;

+                case 'N':

+                        lookupself = 0;

+                        break;

+

 #ifdef	SecurID

 		case 's':

 			/* SecurID required */

@@ -393,6 +398,7 @@

 #endif

 	fprintf(stderr, " [-L login_program]");

 	fprintf(stderr, " [-n]");

+	fprintf(stderr, " [-N]");

 #ifdef	SecurID

 	fprintf(stderr, " [-s]");

 #endif

@@ -691,15 +697,20 @@

 		memset(&hints, '\0', sizeof(hints));

 		hints.ai_socktype = SOCK_STREAM;

-		hints.ai_flags = AI_ADDRCONFIG;

+		hints.ai_flags = AI_CANONNAME;

 		gethostname(host_name, sizeof(host_name));

-		if ((e = getaddrinfo(host_name, NULL, &hints, &res)) != 0) {

-			if(e != EAI_AGAIN) {

-				fprintf(stderr, "getaddrinfo: localhost %s\n", 

-				        gai_strerror(e));

-				exit(1);

-			}

+                /*

+                 * Optionally canonicalize the local host name, in case

+                 * gethostname() returns foo, we want foo.example.com

+                 */

+		if (lookupself &&

+                    (e = getaddrinfo(host_name, NULL, &hints, &res)) == 0) {

+                        if (res->ai_canonname) {

+                                strncpy(host_name, res->ai_canonname,

+                                                        sizeof(host_name)-1);

+                                host_name[sizeof(host_name)-1] = 0;

+                        }

 		}

 		if(res)

 			freeaddrinfo(res);

--- netkit-telnet-0.17.orig/telnetd/telnetd.8.reallynodns	2009-03-12 14:54:54.000000000 -0700

+++ netkit-telnet-0.17.orig/telnetd/telnetd.8	2009-03-12 14:56:58.000000000 -0700

@@ -42,7 +42,7 @@

 protocol server

 .Sh SYNOPSIS

 .Nm /usr/sbin/in.telnetd

-.Op Fl hns

+.Op Fl hnNs

 .Op Fl a Ar authmode

 .Op Fl D Ar debugmode

 .Op Fl L Ar loginprg

@@ -175,6 +175,10 @@

 if the client is still there, so that idle connections

 from machines that have crashed or can no longer

 be reached may be cleaned up.

+.It Fl N

+Do not use DNS to canonicalize the local hostname;

+.Fn gethostname 2

+returns a fully qualified name.

 .It Fl s

 This option is only enabled if

 .Nm telnetd