Awesome
A TCP port redirector for UNIX
This is a TCP port redirector for UNIX. It can be run under inetd or as a standalone daemon (in which case it handles multiple connections). It is 8-bit clean, not limited to line mode, yet small and lightweight. If you want access control, run it under xinetd or inetd with TCP wrappers.
redir
listens for TCP connections on a given SRC:PORT
. When clients
connect to redir
it initiates a connection to the server on DST:PORT
to pass data between them. The SRC
and DST
are from the perspective
of redir
.
-------> SRC:PORT -----> DST:PORT
Request: CLIENT -------> redir --------> SERVER
Response: CLIENT <------- redir <-------- SERVER
--bind=addr
Note: the --bind=ADDR
argument is to limit redir
on the server
side reply, in case the box redir
runs on have multiple addresses or
interfaces on the server side.
redir
finds most of its applications in traversing firewalls, but, of course, there are other use-cases. For a UDP port redirector, see uredir
Usage
Consult the man page for details.
Usage: redir [-hinspv] [-b IP] [-f TYPE] [-I NAME] [-l LEVEL] [-t SEC]
[-x STR] [-m BPS] [-o FLAG] [-w MSEC] [-z BYTES]
[SRC]:PORT [DST]:PORT
Options:
-b, --bind=IP Listen only to IP on the server-side connection,
how DST connects to redir. Not applicable with -p
-f, --ftp=TYPE Redirect FTP connections. Where type is
one of: 'port', 'pasv', or 'both'
-h, --help Show this help text
-i, --inetd Run from inetd, SRC:PORT comes from stdin
Usage: redir [OPTIONS] [DST]:PORT
-I, --ident=NAME Identity, tag syslog messages with NAME
Also used as service name for TCP wrappers
-l, --loglevel=LEVEL Set log level: none, err, notice*, info, debug
-n, --foreground Run in foreground, do not detach from terminal
-p, --transproxy Run in Linux's transparent proxy mode
-s, --syslog Log messages to syslog
-t, --timeout=SEC Set timeout to SEC seconds, default off (0)
-v, --version Show program version
-x, --connect=STR CONNECT string passed to proxy server
Traffic Shaping:
-m, --max-bandwidth=BPS Limit the bandwidth to BPS bits/second
-o, --wait-in-out=FLAG Wait for in(1), out(2), or in&out(3)
-w, --random-wait=MSEC Wait MSEC milliseconds before each packet
-z, --bufsize=BYTES Size of the traffic shaping buffer
SRC and DST are optional, redir will revert to use 0.0.0.0 (ANY)
Old Syntax
Command line options changed in v3.0. A limited subset of the old
syntax is available with the --enable-compat
configure option.
This implicitly also enables -n
by default.
The following subset of the old syntax are available:
--lport=PORT Local port (when not running from inetd)
--laddr=ADDRESS Local address (when not running from inetd)
--cport=PORT Remote port to redirect traffic to
--caddr=ADDRESS Remote address to redirect traffic to
Examples
To redirect port 80 to a webserver listening on loopback port 8080,
remember to use sudo
when using priviliged ports:
sudo redir :80 127.0.0.1:8080
This starts redir
as a standard UNIX daemon in the background, with
all log messages sent to the syslog. Use -n
to foreground and see log
messages on stderr
.
To run redir
from a process monitor like Finit or systemd, tell it
to not background itself and to only use the syslog for log messages:
redir -n -s :80 127.0.0.1:8080
An /etc/inetd.conf
line of the same looks very similar:
http stream tcp nowait root /usr/sbin/tcpd /usr/bin/redir -n -s -i 127.0.0.1:8080
When running multiple redir instances it can be useful to change how they identify themselves:
redir -I nntp www:119 netgate:119
redir -I pop3 ftp:110 netgate:110
This starts an NNTP and a POP3 port redirector, named accordingly.
Previously therere was a redir-wrapper
script included in the
distribution, but that is no longer maintained.
Building
Redir comes with a GNU configure script which you can use to adapt the build to your needs. If you would like to remove support for some extended options (for the sake of speed, code size, whatever), try the following options to configure:
--enable-compat Enable limited v2.x command line syntax
--disable-shaper Disable traffic shaping code
--disable-ftp Disable FTP redirection support
The GNU Configure & Build system use /usr/local
as the default install
prefix. For most use-cases this is fine, but if you want to change this
to /usr
use the --prefix=/usr
configure option:
./configure --prefix=/usr
make -j5
sudo make install-strip
Building from GIT sources require you have automake
and autoconf
installed. Use ./autogen.sh
to create the configure script.
Origin & References
Redir was originally created by Nigel Metheringham and Sam Creasey. It is now maintained at GitHub by Joachim Wiberg. Use GitHub to file bug reports, clone, or send pull requests for bug fixes and extensions.
Redir is distributed under the terms of the GNU Public Licence, version 2 or later, distributed with this source archive in the file COPYING.