chiark / gitweb /
configure.ac: Abolish use of `libtool'.
[tripe] / contrib / knock.in
CommitLineData
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1#! /bin/sh
2
3set -e
4
5### This script performs the passive side of a dynamic association. It is
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6### intended to be set as the forced command in an `.ssh/authorized_keys'
7### file. Specifically, for each dynamic peer, add a line to
8### `.ssh/authorized_keys' of the form
b147e573 9###
0f51cf5a 10### environment="TRIPE_USER=PEER" ssh-rsa ...
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11###
12### There's an additional wrinkle. Suppose that the passive TrIPE endpoint
13### is behind a NAT, and the SSH gateway is on a different machine. The
14### gateway should have its own `tripe' user, and this script should again be
15### its shell. On the gateway, add a `.ssh/authorized_keys' entry
16###
0f51cf5a 17### environment="TRIPE_USER=tripe@SERVER:PEER" ssh-rsa ...
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18###
19### for the dynamic endpoint. On the passive endpoint itself, you need an
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20### entry for the gateway's `tripe' user's key, with `TRIPE_GATEWAY' set to
21### any value, like
22###
23### environment="TRIPE_GATEWAY=t" ssh-rsa ...
24###
25### For backwards compatibility, it can also be set as the `tripe' user's
26### shell, with the `[tripe@SERVER:]PEER' indicator set as the forced
27### command. If there are no forced command or `TRIPE_*' environment
28### variables then it is assumed that a gateway is calling.
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29
30: ${prefix=@prefix@} ${exec_prefix=@exec_prefix@}
31: ${bindir=@bindir@}
32: ${TRIPEDIR=@configdir@} ${TRIPESOCK=@socketdir@/tripesock}
33: ${tripectl=$bindir/tripectl}
34export TRIPEDIR TRIPESOCK
35
d3731285 36## Make sure we're being called properly, and figure out the peer identity.
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37case "${TRIPE_USER+t},${TRIPE_GATEWAY+t},$#,$1" in
38 t,,0,) set -- "$TRIPE_USER" ;;
39 ,t,0,) set -- $SSH_ORIGINAL_COMMAND; unset SSH_ORIGINAL_COMMAND ;;
40 ,,2,-c) ;;
d3731285 41 *)
0f51cf5a 42 echo >&2 "usage: $0 -c [SERVER:]PEER [ACTION]"
d3731285 43 exit 1
b147e573 44 ;;
d3731285 45esac
b147e573 46
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47## Examine the peer identifier and work out how to proceed.
48case "$#,$1" in
0f51cf5a 49 0,*) echo >&2 "missing peer identifier"; exit 1 ;;
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50 *:*) mode=proxy server=${1%:*} user=${1##*:} ;;
51 *) mode=local user=$1 ;;
52esac
53shift
b147e573 54
0f51cf5a 55## Fetch the optional command from where SSH stashed it.
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56case "$#" in 0) set -- $SSH_ORIGINAL_COMMAND ;; esac
57case "$#,$1" in
58 0, | 1,hello) act=hello ;;
59 1,goodbye) act=goodbye ;;
60 *) echo >&2 "$0: unknown action spec \`$*'"; exit 1 ;;
61esac
62
63## Now actually do something.
64case "$mode,$act" in
65 proxy,*)
66 exec ssh "$server" "$user" "$act"
67 ;;
68 local,hello)
69 exec $tripectl SVCSUBMIT connect passive "$user"
70 ;;
71 local,goodbye)
72 peer=$($tripectl SVCSUBMIT connect userpeer "$user")
73 exec $tripectl KILL "$peer"
74 ;;
b147e573 75 *)
d3731285 76 echo >&2 "$0: unknown mode/action $mode/$act"
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77 exit 1
78 ;;
b147e573 79esac