path: root/doc/uanytun.8.txt

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>[..]]] ]
  [ -U|--debug ]
  [ -i|--interface <ip-address> ]
  [ -p|--port <port>[:<port>] ]
  [ -Y|--rail-mode ]
  [ -r|--remote-host <hostname|ip> ]
  [ -o|--remote-port <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
   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 'syslog:3,uanytun,daemon' is added. +
   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>

*-U, --debug*::
   This option instructs *uAnytun* to run in debug mode. It implicits *-D*
   (don't daemonize) and adds a log target with the configuration
   'stdout:5' (logging with maximum level). In future releases there might
   be additional output when this option is supplied.

*-i, --interface '<ip address>'*::
   This IP address is used as the sender address for outgoing
   packets. The default is to not use a special interface and just
   bind on all interfaces.

*-p, --port '<port>[:<port>]'*::
   The local UDP port that is used to send and receive the
   payload data. The two tunnel endpoints can use different
   ports. The default port is 4444.
   In *RAIL* mode you must specify a port range. See section
   *RAIL* below to find out what this is.

*-Y, --rail-mode*::
   This option instructs *uAnytun* to run in RAIL mode. See section
   *RAIL* below to find out what this is.

*-r, --remote-host '<hostname|ip>'*::
   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>[:<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.
   When RAIL mode is enabled the port range must be of the same length
   as the range defined with *-p, --port*.
   See section *RAIL* below for more information about this mode.

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

   '<local>';; the local IP address for the tun/tap device
   '<prefix>';; the prefix length of the network

*-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 compatibility
   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, e.g.
   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, e.g.
   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. +
   If HMAC-SHA1 is used, the packet length is increased. The additional bytes
   contain the authentication data. see *--auth-tag-length* for more info. +
   Possible values:

   'null';; no message authentication
   'sha1';; HMAC-SHA1, default value

*-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.


RAIL
----

*RAIL* stands for Redundant Array of Inexpensive Links. Like RAID spreads
the blocks of a disk volume over multiple physical disks, *RAIL* will spread the
UDP packets over multiple physical links. More precisly for each packet *uAnytun*
reads, from the TUN/TAP device, it will send out multiple UDP packets. All of those to
the same host but with different destination ports. Using policy-based routing mechanisms
these packets can now be seperated and sent out on several interfaces.
The server-side will then pick the first of the packets that arrive and discards all others.
For this to work the size of the sequence window (*-w*) must not be set to 0.
As soon as the server-side learns the remote endpoints of all or some of the links it will
as well send multiple UDP packets for each payload packet.


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.


Rail Setup for 3 links:
~~~~~~~~~~~~~~~~~~~~~~~

Client:
^^^^^^^

uanytun -t tun -n 192.168.42.2/30 -c aes-ctr-256 -k aes-ctr-256 -E rail_MODE_is_VERY_cool
        -e client -w 64 -Y -p 1233:1235 -r rail.example.com -o 4440:4442

Server:
^^^^^^^
uanytun -t tun -n 192.168.42.1/30 -c aes-ctr-256 -k aes-ctr-256 -E rail_MODE_is_VERY_cool
        -e server -w 64 -Y -p 4440:4442


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) 2008-2017 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.