uanytun(8)
==========

NAME
----
uanytun - micro anycast tunneling daemon

SYNOPSIS
--------

*uanytun*
[ *-h|--help* ]
[ *-D|--nodaemonize* ]
[ *-u|--username* <username> ]
[ *-g|--groupname* <groupname> ]
[ *-C|--chroot* <path> ]
[ *-P|--write-pid* <filename> ]
[ *-L|--log* <target>:<level>[,<param1>[,<param2>[..]]] ]
[ *-i|--interface* <ip-address> ]
[ *-p|--port* <port> ]
[ *-r|--remote-host* <hostname|ip> ]
[ *-o|--remote-port* <port> ]
[ *-4|--ipv4-only* ]
[ *-6|--ipv6-only* ]
[ *-d|--dev* <name> ]
[ *-t|--type* <tun|tap> ]
[ *-n|--ifconfig* <local>/<prefix> ]
[ *-x|--post-up-script* <script> ]
[ *-m|--mux* <mux-id> ]
[ *-s|--sender-id* <sender id> ]
[ *-w|--window-size* <window size> ]
[ *-k|--kd-prf* <kd-prf type> ]
[ *-e|--role <role>* ]
[ *-E|--passphrase* <pass phrase> ]
[ *-K|--key* <master key> ]
[ *-A|--salt* <master salt> ]
[ *-c|--cipher* <cipher type> ]
[ *-a|--auth-algo* <algo type> ]
[ *-b|--auth-tag-length* <length> ]

DESCRIPTION
-----------

*uAnytun* is a tiny implementation of the Secure Anycast Tunneling Protocol
(SATP). It provides a complete VPN solution similar to OpenVPN or
IPsec in tunnel mode. The main difference is that anycast enables the
setup of tunnels between an arbitrary combination of anycast, unicast
and multicast hosts. Unlike Anytun which is a full featured implementation 
uAnytun has no support for multiple connections or synchronisation. It is a 
small single threaded implementation intended to act as a client on small 
platforms.

OPTIONS
-------

*uAnytun* has been designed as a peer to peer application, so there is
no difference between client and server. The following options can be
passed to the daemon:

-D|--nodaemonize
~~~~~~~~~~~~~~~~

This option instructs *uAnytun* to run in foreground
instead of becoming a daemon which is the default.

-u|--username <username>
~~~~~~~~~~~~~~~~~~~~~~~~

run as this user. If no group is specified (*-g*) the default group of 
the user is used. The default is to not drop privileges.

-g|--groupname <groupname>
~~~~~~~~~~~~~~~~~~~~~~~~~~

run as this group. If no username is specified (*-u*) this gets ignored.
The default is to not drop privileges.

-C|--chroot <path>
~~~~~~~~~~~~~~~~~~

Instruct *uAnytun* to run in a chroot jail. The default is 
to not run in chroot.

-P|--write-pid <filename>
~~~~~~~~~~~~~~~~~~~~~~~~~

Instruct *uAnytun* to write it's pid to this file. The default is 
to not create a pid file.

-L|--log <target>:<level>[,<param1>[,<param2>[..]]]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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 
hast 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 following targets are supported:

* *syslog* - log to syslog daemon, parameters <level>[,<logname>[,<facility>]]
* *file* - log to file, parameters <level>[,<path>]
* *stdout* - log to standard output, parameters <level>
* *stderr* - log to standard error, parameters <level> 

The file target can be used more the once with different levels.
If no target is provided at the command line a single target with the 
following config is added:

*syslog:3,uanytun,daemon*


-i|--interface <ip address>
~~~~~~~~~~~~~~~~~~~~~~~~~~~

This IP address is used as the sender address for outgoing
packets. The default is to not use a special inteface and just
bind on all interfaces.

-p|--port <port>
~~~~~~~~~~~~~~~~

local port to bind to

The local UDP port that is used to send and receive the
payload data. The two tunnel endpoints can use different
ports. default: 4444

-r|--remote-host <hostname|ip>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

remote host

This option can be used to specify the remote tunnel
endpoint. In case of anycast tunnel endpoints, the
anycast IP address has to be used. If you do not specify
an address, it is automatically determined after receiving
the first data packet.

-o|--remote-port <port>
~~~~~~~~~~~~~~~~~~~~~~~

remote port

The UDP port used for payload data by the remote host
(specified with -p on the remote host). If you do not specify
a port, it is automatically determined after receiving
the first data packet.

-4|--ipv4-only
~~~~~~~~~~~~~~

Resolv to IPv4 addresses only. The default is to resolv both
IPv4 and IPv6 addresses.

-6|--ipv6-only
~~~~~~~~~~~~~~

Resolv to IPv6 addresses only. The default is to resolv both
IPv4 and IPv6 addresses.

-d|--dev <name>
~~~~~~~~~~~~~~~

device name

By default, tapN is used for Ethernet tunnel interfaces,
and tunN for IP tunnels, respectively. This option can
be used to manually override these defaults.

-t|--type <tun|tap>
~~~~~~~~~~~~~~~~~~~

device type

Type of the tunnels to create. Use tap for Ethernet
tunnels, tun for IP tunnels.

-n|--ifconfig <local>/<prefix>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

*<local>* the local IP address for the tun/tap device

*<prefix>* the prefix length of the network

The local IP address and prefix length. The remote tunnel endpoint
has to use a different IP address in the same subnet.

-x|--post-up-script <script>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This option instructs *uAnytun* to run this script after the interface 
is created. By default no script will be executed.

-m|--mux <mux-id>
~~~~~~~~~~~~~~~~~

the multiplex id to use. default: 0

-s|--sender-id  <sender id>
~~~~~~~~~~~~~~~~~~~~~~~~~~~

Each anycast tunnel endpoint needs a unique sender id
(1, 2, 3, ...). It is needed to distinguish the senders
in case of replay attacks. As *uAnytun* does not support 
synchronisation it can't be used as an anycast endpoint therefore 
this option is quite useless but implemented for compability 
reasons. default: 0

-w|--window-size <window size>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

seqence window size

Sometimes, packets arrive out of order on the receiver
side. This option defines the size of a list of received
packets' sequence numbers. If, according to this list,
a received packet has been previously received or has
been transmitted in the past, and is therefore not in
the list anymore, this is interpreted as a replay attack
and the packet is dropped. A value of 0 deactivates this
list and, as a consequence, the replay protection employed
by filtering packets according to their secuence number.
By default the sequence window is disabled and therefore a
window size of 0 is used.

-k|--kd--prf <kd-prf type>
~~~~~~~~~~~~~~~~~~~~~~~~~~

key derivation pseudo random function.

The pseudo random function which is used for calculating the 
session keys and session salt.

Possible values:

* *null* - no random function, keys and salt are set to 0..00
* *aes-ctr* - AES in counter mode with 128 Bits, default value
* *aes-ctr-128* - AES in counter mode with 128 Bits
* *aes-ctr-192* - AES in counter mode with 192 Bits
* *aes-ctr-256* - AES in counter mode with 256 Bits

-e|--role <role>
~~~~~~~~~~~~~~~~

SATP uses different session keys for inbound and outbound traffic. The
role parameter is used to determine which keys to use for outbound or
inbound packets. On both sides of a vpn connection different roles have 
to be used. Possible values are *left* and *right*. You may also use 
*alice* or *server* as a replacement for *left* and *bob* or *client* as 
a replacement for *right*. By default *left* is used.

-E|--passphrase <pass phrase>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This passphrase is used to generate the master key and master salt.
For the master key the last n bits of the SHA256 digest of the 
passphrase (where n is the length of the master key in bits) is used. 
The master salt gets generated with the SHA1 digest. 
You may force a specific key and or salt by using *--key* and *--salt*.

-K|--key <master key>
~~~~~~~~~~~~~~~~~~~~~

master key to use for key derivation

Master key in hexadecimal notation, eg
01a2b3c4d5e6f708a9b0cadbecfd0fa1, with a mandatory length
of 32, 48 or 64 characters (128, 192 or 256 bits).

-A|--salt <master salt>
~~~~~~~~~~~~~~~~~~~~~~~

master salt to use for key derivation

Master salt in hexadecimal notation, eg
01a2b3c4d5e6f708a9b0cadbecfd, with a mandatory length
of 28 characters (14 bytes).

-c|--cipher <cipher type>
~~~~~~~~~~~~~~~~~~~~~~~~~

payload encryption algorithm

Encryption algorithm used for encrypting the payload

Possible values:

* *null* - no encryption
* *aes-ctr* - AES in counter mode with 128 Bits, default value
* *aes-ctr-128* - AES in counter mode with 128 Bits
* *aes-ctr-192* - AES in counter mode with 192 Bits
* *aes-ctr-256* - AES in counter mode with 256 Bits

-a|--auth-algo <algo type>
~~~~~~~~~~~~~~~~~~~~~~~~~~

message authentication algorithm

This option sets the message authentication algorithm.

Possible values:

* *null* - no message authentication
* *sha1* - HMAC-SHA1, default value

If HMAC-SHA1 is used, the packet length is increased. The additional bytes 
contain the authentication data. see *-b|--auth-tag-length* for more info.

-b|--auth-tag-length <length>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The number of bytes to use for the auth tag. This value defaults to 10 bytes 
unless the *null* auth algo is used in which case it defaults to 0. 

EXAMPLES
--------

P2P Setup between two unicast enpoints:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Host A:
^^^^^^^

uanytun -r hostb.example.com -t tun -n 192.168.123.1/30 -c aes-ctr-256 -k aes-ctr-256 \
        -E have_a_very_safe_and_productive_day -e left

Host B:
^^^^^^^
uanytun -r hosta.example.com -t tun -n 192.168.123.2/30 -c aes-ctr-256 -k aes-ctr-256 \
        -E have_a_very_safe_and_productive_day -e right


One unicast and one anycast tunnel endpoint:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
Unicast tunnel endpoint:
^^^^^^^^^^^^^^^^^^^^^^^^

uanytun -r anycast.anytun.org -d anytun0 -t tun -n 192.0.2.2/30 -a null -c null -w 0 -e client

Anycast tunnel endpoints:
^^^^^^^^^^^^^^^^^^^^^^^^^
As *uAnytun* can't work as an anycast endpoint it can't be used for this purpose. You
have to use *anytun* for that job.


BUGS
----
Most likely there are some bugs in *uAnytun*. If you find a bug, please let
the developers know at uanytun@anytun.org. Of course, patches are preferred.

AUTHORS
-------

Christian Pointner <equinox@anytun.org>

RESOURCES
---------

Main web site: http://www.anytun.org/


COPYING
-------

Copyright \(C) 2008-2009 Christian Pointner. This  program is  free 
software; you can redistribute it and/or modify it under the terms 
of the GNU General Public License version 3 as published by the 
Free Software Foundation.