path: root/doc/tcpproxy.8

'\" t
.\"     Title: tcpproxy
.\"    Author: [see the "AUTHORS" section]
.\" Generator: DocBook XSL Stylesheets v1.76.1 <http://docbook.sf.net/>
.\"      Date: 10/07/2013
.\"    Manual: \ \&
.\"    Source: \ \&
.\"  Language: English
.\"
.TH "TCPPROXY" "8" "10/07/2013" "\ \&" "\ \&"
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.SH "NAME"
tcpproxy \- IPv4/IPv6 tcp connection proxy
.SH "SYNOPSIS"
.sp
.nf
\fBtcpproxy\fR
  [ \fB\-h|\-\-help\fR ]
  [ \fB\-D|\-\-nodaemonize\fR ]
  [ \fB\-u|\-\-username\fR <username> ]
  [ \fB\-g|\-\-groupname\fR <groupname> ]
  [ \fB\-C|\-\-chroot\fR <path> ]
  [ \fB\-P|\-\-write\-pid\fR <filename> ]
  [ \fB\-L|\-\-log\fR <target>:<level>[,<param1>[,<param2>[\&.\&.]]] ]
  [ \fB\-U|\-\-debug\fR ]
  [ \fB\-l|\-\-local\-addr\fR <host> ]
  [ \fB\-t|\-\-local\-resolv\fR (ipv4|4|ipv6|6) ]
  [ \fB\-p|\-\-local\-port\fR <service> ]
  [ \fB\-r|\-\-remote\-addr\fR <host> ]
  [ \fB\-R|\-\-remote\-resolv\fR (ipv4|4|ipv6|6) ]
  [ \fB\-o|\-\-remote\-port\fR <service> ]
  [ \fB\-s|\-\-source\-addr\fR <host> ]
  [ \fB\-b|\-\-buffer\-size\fR <size> ]
  [ \fB\-c|\-\-config\fR <file> ]
.fi
.SH "DESCRIPTION"
.sp
\fBtcpproxy\fR is a simple tcp connection proxy which combines the features of rinetd and 6tunnel\&. \fBtcpproxy\fR supports IPv4 and IPv6 and also supports connections from IPv6 to IPv4 endpoints and vice versa\&.
.SH "OPTIONS"
.sp
The following options can be passed to the \fBtcpproxy\fR daemon:
.PP
\fB\-D, \-\-nodaemonize\fR
.RS 4
This option instructs
\fBtcpproxy\fR
to run in foreground instead of becoming a daemon which is the default\&.
.RE
.PP
\fB\-u, \-\-username <username>\fR
.RS 4
run as this user\&. If no group is specified (\fB\-g\fR) the default group of the user is used\&. The default is to not drop privileges\&.
.RE
.PP
\fB\-g, \-\-groupname <groupname>\fR
.RS 4
run as this group\&. If no username is specified (\fB\-u\fR) this gets ignored\&. The default is to not drop privileges\&.
.RE
.PP
\fB\-C, \-\-chroot <path>\fR
.RS 4
Instruct
\fBtcpproxy\fR
to run in a chroot jail\&. The default is to not run in chroot\&.
.RE
.PP
\fB\-P, \-\-write\-pid <filename>\fR
.RS 4
Instruct
\fBtcpproxy\fR
to write it\(cqs pid to this file\&. The default is to not create a pid file\&.
.RE
.PP
\fB\-L, \-\-log <target>:<level>[,<param1>[,<param2>[\&.\&.]]]\fR
.RS 4
add log target to logging system\&. This can be invoked several times in order to log to different targets at the same time\&. Every target has its own log level which is a number between 0 and 5\&. Where 0 means disabling log and 5 means debug messages are enabled\&.

The file target can be used more than once with different levels\&. If no target is provided at the command line a single target with the config
\fBsyslog:3,tcpproxy,daemon\fR
is added\&.

The following targets are supported:
.PP
\fBsyslog\fR
.RS 4
log to syslog daemon, parameters <level>[,<logname>[,<facility>]]
.RE
.PP
\fBfile\fR
.RS 4
log to file, parameters <level>[,<path>]
.RE
.PP
\fBstdout\fR
.RS 4
log to standard output, parameters <level>
.RE
.PP
\fBstderr\fR
.RS 4
log to standard error, parameters <level>
.RE
.RE
.PP
\fB\-U, \-\-debug\fR
.RS 4
This option instructs
\fBtcpproxy\fR
to run in debug mode\&. It implicits
\fB\-D\fR
(don\(cqt daemonize) and adds a log target with the configuration
\fBstdout:5\fR
(logging with maximum level)\&. In future releases there might be additional output when this option is supplied\&.
.RE
.PP
\fB\-l, \-\-local\-addr <host>\fR
.RS 4
The local address to bind to\&. By default
\fBtcpproxy\fR
will listen on any interface (IPv6 and IPv4)\&.
.RE
.PP
\fB\-t|\-\-local\-resolv (ipv4|4|ipv6|6)\fR
.RS 4
When resolving the local address (see above) use only IPv4 or IPv6\&. The default is to resolv both\&.
.RE
.PP
\fB\-p, \-\-local\-port <service>\fR
.RS 4
The local port to bind to\&. By default there is no port defined in which case
\fBtcpproxy\fR
will try to read the configuration file\&.
.RE
.PP
\fB\-r, \-\-remote\-addr <host>\fR
.RS 4
The remote address to connect to\&. Unless the configuration file should be used this must be set to a valid address or hostname\&.
.RE
.PP
\fB\-R|\-\-remote\-resolv (ipv4|4|ipv6|6)\fR
.RS 4
When resolving the remote address (see above) use only IPv4 or IPv6\&. The default is to resolv both\&. Mind that this also effects resolving of the source address (see below) as the remote and source addresses must be of the same protocol familiy\&.
.RE
.PP
\fB\-o, \-\-remote\-port <service>\fR
.RS 4
The remote port to connect to\&. Unless the configuration file should be used this must be set to a valid port or servicename\&.
.RE
.PP
\fB\-s, \-\-source\-addr <host>\fR
.RS 4
Instruct tcpproxy to use this source address for connections to
\fB\-R|\-\-remote\-address\fR\&. By default
\fBtcpproxy\fR
uses the default source address for the defined remote host\&.
.RE
.PP
\fB\-b, \-\-buffer\-size <size>\fR
.RS 4
The size of the transmit buffers to use\&.
\fBtcpproxy\fR
will allocate two buffers of this size for any client which is connected\&. By default a value of 10Kbytes is used\&.
.RE
.PP
\fB\-c, \-\-config <file>\fR
.RS 4
The path to the configuration file to be used\&. This is only evaluated if the local port is omitted\&.
.RE
.SH "CONFIGURATION FILE"
.sp
If the configuratin file is used it should contain one or more of the following stanzas:
.sp
.if n \{\
.RS 4
.\}
.nf
listen (*|address|hostname) (port\-number|service\-name)
{
  resolv: (ipv4|ipv6)
  remote: (address|hostname) (port\-number|service\-name);
  remote\-resolv: (ipv4|ipv6);
  source: (address|hostname);
};
.fi
.if n \{\
.RE
.\}
.sp
Everything between the curly brackets except for the \fBremote\fR parameter may be omitted\&.
.SH "SIGNALS"
.sp
After receiving the HUP signal \fBtcpproxy\fR tries to reload the configuration file\&. It only reopens a listen socket if the local address and or port has changed\&. Therefore reloading the configuration after the daemon has dropped privileges is safe as long as there are no changes in the local address and port\&. However this is only of concern if any of the listen ports is a privileged port (<1024)\&. If there is a syntax error at the configuration file all changes are discarded\&. On SIGUSR1 \fBtcpproxy\fR prints some information about the listening sockets and after SIGUSR2 information about open client connections is printed\&. This is sent to all configured log targets at a level of 3\&.
.SH "BUGS"
.sp
Most likely there are some bugs in \fBtcpproxy\fR\&. If you find a bug, please let the developers know at tcpproxy@spreadspace\&.org\&. Of course, patches are preferred\&.
.SH "SEE ALSO"
.sp
rinetd(8)
.SH "AUTHORS"
.sp
Christian Pointner <equinox@spreadspace\&.org>
.SH "RESOURCES"
.sp
Main web site: http://www\&.spreadspace\&.org/tcpproxy/
.SH "COPYING"
.sp
Copyright (C) 2010\-2013 Christian Pointner\&. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or any later version\&.