#!/usr/bin/ksh93

#
# Ethernet/tap forwarding via ssh
#

set -o xtrace
set -o errexit
set -o nounset

# list of commands our ssh session should execute
typeset -a sshcmds=(
	#
	# cleanup:
	#
	# we need to clean up the bridge interface ourselves, if
	# we do not do that we risk getting that any subsequent
	# ifconfig/ip/etc command hangs
	#
	'(( trap_once=0 )) ;'
	"netcleanup() { "
		'(( trap_once++ > 0 )) && return 0 ;'
		"set +o errexit ;"
		"brctl delif br19 tap19 ;"
		"brctl delif br19 eno1 ;"
		"ifconfig tap19 down ;"
		"ifconfig br19 down ;"
		"brctl delbr br19 ;"
	"} ;"
	'trap netcleanup EXIT ;'
	'trap netcleanup HUP ;'

	"set -o xtrace ;"
	"set -o errexit ;"
	"brctl addbr br19 ;"
	"brctl addif br19 tap19 ;"
	"brctl addif br19 eno1 ;"
	"brctl show ;"
	"ifconfig tap19 promisc ;"
	"ifconfig tap19 up ;"
	"ifconfig br19 up ;"

	"read dummy ;" # dummy wait

	'kill -s HUP -${PPID} ;'
)

ssh \
	-o ExitOnForwardFailure=yes \
	-o PermitLocalCommand=yes \
	-o LocalCommand="ifconfig tap19 up" \
	-o Tunnel=ethernet -w 19:19 \
	root@10.49.20.202 \
	"${sshcmds[*]}"

# cleanup
# ...

# EOF.