Manual Pages  — PPPCTL

This utility provides command line control of the ppp(8) daemon. Its primary use is to facilitate simple scripts that control a running daemon.

The pppctl utility is passed at least one argument, specifying the socket on which ppp is listening. Refer to the 'set server' command of ppp for details. If the socket contains a leading '/', it is taken as an AF_LOCAL socket. If it contains a colon, it is treated as a host :port pair, otherwise it is treated as a TCP port specification on the local machine (127.0.0.1). Both the host and port may be specified numerically if you wish to avoid a DNS lookup or do not have an entry for the given port in /etc/services.

All remaining arguments are concatenated to form the command(s) that will be sent to the ppp daemon. If any semi-colon characters are found, they are treated as command delimiters, allowing more than one command in a given 'session'. For example:

pppctl 3000 set timeout 300\; show timeout

Do not forget to escape or quote the ';' as it is a special character for most shells.

If no command arguments are given, pppctl enters interactive mode, where commands are read from standard input. When reading commands, the editline(3) library is used, allowing command-line editing (with editrc(5) defining editing behaviour). The history size defaults to 20 lines.

The following command line options are available:

-v
	Display all data sent to and received from the ppp daemon. Normally, pppctl displays only non-prompt lines received. This option is ignored in interactive mode.
-t n
	Use a timeout of n instead of the default 2 seconds when connecting. This may be required if you wish to control a daemon over a slow (or even a dialup) link.
-p passwd
	Specify the password required by the ppp daemon. If this switch is not used, pppctl will prompt for a password once it has successfully connected to ppp.

If you run ppp in -auto mode, pppctl can be used to automate many frequent tasks (you can actually control ppp in any mode except interactive mode). Use of the -p option is discouraged (even in scripts that are not readable by others) as a ps(1) listing may reveal your secret.

The best way to allow easy, secure pppctl access is to create a local server socket in /etc/ppp/ppp.conf (in the correct section) like this:

set server /var/run/internet "" 0177

This will instruct ppp to create a local domain socket, with srw------- permissions and no password, allowing access only to the user that invoked ppp. Refer to the ppp(8) man page for further details.

You can now create some easy-access scripts. To connect to the internet:

#! /bin/sh
test $# -eq 0 && time=300 || time=$1
exec pppctl /var/run/internet set timeout $time\; dial

To disconnect:

#! /bin/sh
exec pppctl /var/run/internet set timeout 300\; close

To check if the line is up:

#! /bin/sh
pppctl -p '' -v /var/run/internet quit | grep ^PPP >/dev/null
if [ $? -eq 0 ]; then
  echo Link is up
else
  echo Link is down
fi

You can even make a generic script:

#! /bin/sh
exec pppctl /var/run/internet "$@"

You could also use pppctl to control when dial-on-demand works. Suppose you want ppp to run all the time, but you want to prevent dial-out between 8pm and 8am each day. However, any connections active at 8pm should continue to remain active until they are closed or naturally time out.

A cron(8) entry for 8pm which runs

pppctl /var/run/internet set filter dial 0 deny 0 0

will block all further dial requests, and the corresponding 8am entry

pppctl /var/run/internet set filter dial -1

will allow them again.

ps(1), editline(3), editrc(5), services(5), ppp(8)