2 # Copyright (C) 2016 Ian Kelling
4 # Licensed under the Apache License, Version 2.0 (the "License");
5 # you may not use this file except in compliance with the License.
6 # You may obtain a copy of the License at
8 # http://www.apache.org/licenses/LICENSE-2.0
10 # Unless required by applicable law or agreed to in writing, software
11 # distributed under the License is distributed on an "AS IS" BASIS,
12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 # See the License for the specific language governing permissions and
14 # limitations under the License.
16 [[ $EUID == 0 ]] ||
exec sudo
"$BASH_SOURCE" "$@"
18 source /a
/bin
/errhandle
/errcatch-function
19 source /a
/bin
/errhandle
/errallow-function
20 source /a
/bin
/errhandle
/bash-trace-function
25 Usage: mail-route start|stop|show
30 if (( $# != 1 )); then
37 # systemd around stretch release time, would wait until openvpn actually connected,
38 # so this was unnecessary, but now it returns immediately.
40 tun_dev
=$
(ip a show to
10.8.0.4/24 |
sed -rn '1s/^\S+\s+([^:]+).*/\1/p')
41 if [[ $tun_dev == tun
* ]]; then
44 echo "$0: waiting for tun_dev, found: $tun_dev"
52 tun_dev
=$
(iptables
-t nat
-S |
sed -rn "s/^-A POSTROUTING -o (tun[[:digit:]]+) -m mark --mark 0x1 -j SNAT --to-source 10.8.0.4$/\1/p"|
head -n1) ||
printf "failed to find tun device.\n"
53 e
() { "$@" ||
printf "maybe ok failure: %s\n" "$*"; }
56 e
() { printf "${0##*/}: %s\n" "$*"; "$@"; }
57 e iptables
-t mangle
-S
60 e ip route show table
1
69 # note, something like this does not work for packets which
70 # exim is replying to. I don't know why.
71 #iptables -t mangle -A OUTPUT -m owner --uid-owner Debian-exim -j MARK --set-mark 0x1
73 # match source or dest port. when we send to 25, it picks a random high port as
76 for port
in 25 143; do # smtp and imap.
77 e iptables
-t mangle
$iptables_op \
78 OUTPUT
-m tcp
-p tcp
-m multiport
--ports $port -j MARK
--set-mark 0x1
79 e iptables
-t mangle
$iptables_op \
80 OUTPUT
-m tcp
-p tcp
-m multiport
--ports $port -j MARK
--set-mark 0x0 \
81 -d 10.0.0.0/8,172.16.0.0/12,192.168.0.0/16
82 # note, we could have used a custom chain and returned instead of setting the mark again.
83 # in case anyone was ever curious, the inverse of private ips is: #0.0.0.0/5,8.0.0.0/7,11.0.0.0/8,12.0.0.0/6,16.0.0.0/4,32.0.0.0/3,64.0.0.0/2,128.0.0.0/3,160.0.0.0/5,168.0.0.0/6,172.0.0.0/12,172.32.0.0/11,172.64.0.0/10,172.128.0.0/9,173.0.0.0/8,174.0.0.0/7,176.0.0.0/4,192.0.0.0/9,192.128.0.0/11,192.160.0.0/13,192.169.0.0/16,192.170.0.0/15,192.172.0.0/14,192.176.0.0/12,192.192.0.0/10,193.0.0.0/8,194.0.0.0/7,196.0.0.0/6,200.0.0.0/5,208.0.0.0/4,224.0.0.0/3
86 e iptables
-t nat
$iptables_op POSTROUTING
-o $tun_dev -m mark
--mark 0x1 -j SNAT
--to-source 10.8.0.4
87 e ip rule
$ip_op fwmark
1 table
1
88 # note, this rule does not persist when the tun interface is deleted
89 e ip route
$ip_op default via
10.8.0.1 table
1