Add some notes on how to make telnetd actually work

This commit is contained in:
Eric Andersen 2004-09-23 20:08:46 +00:00
parent ca1c1afadc
commit 31ec93e580

View File

@ -492,11 +492,45 @@ config CONFIG_FEATURE_TELNET_AUTOLOGIN
config CONFIG_TELNETD
bool "telnetd"
default n
select CONFIG_LOGIN
help
A daemon for the TELNET protocol, allowing you to log onto the host
running the daemon. Please keep in mind that the TELNET protocol
sends passwords in plain text. If you can't afford the space for
any SSH daemon and you trust your network, you may say 'y' here.
sends passwords in plain text. If you can't afford the space for an
SSH daemon and you trust your network, you may say 'y' here. As a
more secure alternative, you should seriously consider installing the
very small Dropbear SSH daemon instead:
http://matt.ucc.asn.au/dropbear/dropbear.html
Note that for busybox telnetd to work you need several things:
First of all, your kernel needs:
CONFIG_UNIX98_PTYS=y
CONFIG_DEVPTS_FS=y
Next, you need a /dev/pts directory on your root filesystem:
$ ls -ld /dev/pts
drwxr-xr-x 2 root root 0 Sep 23 13:21 /dev/pts/
Next you need the pseudo terminal master multiplexer /dev/ptmx:
$ ls -la /dev/ptmx
crw-rw-rw- 1 root tty 5, 2 Sep 23 13:55 /dev/ptmx
Any /dev/ttyp[0-9]* files you may have can be removed.
Next, you need to mount the devpts filesystem on /dev/pts using:
mount -t devpts devpts /dev/pts
You need to be sure that Busybox has CONFIG_LOGIN and
CONFIG_FEATURE_SUID enabled. And finally, you should make
certain that Busybox has been installed setuid root:
chown root.root /bin/busybox
chmod 4755 /bin/busybox
with all that done, telnetd _should_ work....
config CONFIG_FEATURE_TELNETD_INETD
bool " Support call from inetd only"