--- 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