						-*- outline -*-
*		OPENSSH tunneling [ossh]

** requirements
- openssh-clients > 4.3
- tun/tap interface support

** which one
etcnet utilizes openssh ability to link two tun/tap ifaces.
[ossh] type describes master (initiating) tunnel side, and
[tuntap] type describes slave tunnel side.

** master iface configuration

*** iface/options
TYPE=ossh
# IP address of remote host [MANDATORY]
REMOTE=1.2.3.4
# sshd listen port on remote, defaults to 22
REMOTEPORT=222
# connect as that user, defaults to root
REMOTEUSER=ossh
# remote iface name, defaults to any
REMOTEIF=tun0
# set tuntap interface up on remote, defaults to no,
# assuming $REMOTEIF is always up.
IFUP_REMOTE=yes
# command to invoke on remote to setup $REMOTEIF,
# if IFUP_REMOTE is 'yes'; defaults to /sbin/ifup
REMOTEIFUP='ifconfig tun0 ....'
# and other options for 'ip tuntap ...' except for mode
TUNTAP_OPTIONS=

*** iface/identity
contains private ssh key, corresponding public key
should be installed on remote

*** iface/ipv4address etc
as usual

** limitations
- local interface name MUST be in form tun[0-9]+ or tap[0-9]+
- remote interface name should be of same type, tun or tap

** samples, assuming both ends have etcnet installed:

*** master side [ossh]
--- %< --- tun0/options:
TYPE=ossh
REMOTE=195.112.124.102
REMOTEIF=tun1
--- %< ---

--- %< --- tun0/ipv4address:
172.16.4.3 peer 172.16.4.4/32
--- %< ---

*** slave side [tuntap]
--- %< --- tun1/options:
TYPE=tuntap
--- %< ---

--- %< --- tun1/ipv4address:
172.16.4.4 peer 172.16.4.3/32
--- %< ---
