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modified post b462550ed3 by Anonymous on Thu 14th Apr 2022 13:48
original post fad4 by Anonymous on Thu 14th Apr 2022 13:32
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#!/usr/bin/ksh93

1	1		#!/usr/bin/ksh93
2	2
3	3		#
4	4		# Ethernet/tap forwarding via ssh
5	5		#
6	6
7	7		set -o xtrace
8	8		set -o errexit
9	9		set -o nounset
10	10
11	11		# list of commands our ssh session should execute
12	12		typeset -a sshcmds=(
13	13		#
14	14		# cleanup:
15	15		#
16	16		# we need to clean up the bridge interface ourselves, if
17	17		# we do not do that we risk getting that any subsequent
18	18		# ifconfig/ip/etc command hangs
19	19		#
20	20		'(( trap_once=0 )) ;'
21	21		"netcleanup() { "
22	22		'(( trap_once++ > 0 )) && return 0 ;'
23	23		"set +o errexit ;"
24	24		"brctl delif br19 tap19 ;"
25	25		"brctl delif br19 eno1 ;"
26	26		"ifconfig tap19 down ;"
27	27		"ifconfig br19 down ;"
28	28		"brctl delbr br19 ;"
	29	+	"exit 0 ;"
29	30		"} ;"
30	31		'trap netcleanup EXIT ;'
31	32		'trap netcleanup HUP ;'
32	33
33	34		"set -o xtrace ;"
34	35		"set -o errexit ;"
35	36		"brctl addbr br19 ;"
36	37		"brctl addif br19 tap19 ;"
37	38		"brctl addif br19 eno1 ;"
38	39		"brctl show ;"
39	40		"ifconfig tap19 promisc ;"
40	41		"ifconfig tap19 up ;"
41	42		"ifconfig br19 up ;"
42	43
43		-	"read dummy ;" # dummy wait
	44	+	"read dummy ;" # wait
44	45
45		-	'kill -s HUP -${PPID} ;'
	46	+	# this is nasty:
	47	+	# we have to tell sshd to quit, and then busy-wait
46	52		)
47	53
48	54		ssh \
49	55		-o ExitOnForwardFailure=yes \
50	56		-o PermitLocalCommand=yes \
51	57		-o LocalCommand="ifconfig tap19 up" \
52	58		-o Tunnel=ethernet -w 19:19 \
53	59		root@10.49.20.202 \
54	60		"${sshcmds[*]}"
55	61
56	62		# cleanup
57	63		# ...
58	64
59	65		# EOF.
60	66