On Sat, Mar 28, 2009 at 06:45:13PM +0200, I bravely wrote:
> то был нарисован прицепленный скриптик, надеюсь, достаточно
> самодокументированный. При необходимости его можно обобщить
> от двух альтернатив, но решил не усложнять без таковой.
> Также здесь:
> http://fly.osdn.org.ua/~mike/works/misc/notebook-portforward
Поправочка: как root cronjob оказался неэффективным:
++ iptables -L PREROUTING -t nat -n
/usr/local/sbin/notebook-portforward: line 43: iptables: command not found
Пришлось явно добавить /sbin в PATH, обновил.
--
---- WBR, Michael Shigorin <[email protected]>
------ Linux.Kiev http://www.linux.kiev.ua/
#!/bin/sh
# check which IP is reachable since the notebook can be
# connected via either Ethernet or WiFi, or both;
# adjust portforwarding (which must otherwise be
# already set up correctly -- like not forgetting
# -A INPUT -d $IP -p tcp -m tcp --dport $DPT -j ACCEPT
#
# try to ping an already existing portforward target;
# if unreachable or none, try to ping/add another one
#
# (c) 2009 Michael Shigorin <mike altlinux org>
# use, modify, distribute, cronjob this freely
PATH=/sbin:$PATH
IP=EX.TER.NAL.IP # 123.45.67.8
IP_E=NOTE.BOOK.ETH.IP # 192.168.1.2
IP_W=NOTE.BOOK.WIFI.IP # 192.168.1.3
PORT=EXT_PORT # 12345
DPT=DEST_PORT # 22
COUNT=0
IFS=":"
ipt()
{
iptables "$1" PREROUTING -t nat \
-d "$IP" -p tcp -m tcp \
--dport "$PORT" \
-j DNAT --to-destination "$2:$DPT"
}
remove() { ipt -D "$1"; }
add() { ipt -A "$1"; }
try() { ping -w1 "$1" >&/dev/null; }
# is current one reachable?
COUNT="`iptables -L PREROUTING -t nat -n \
| fgrep "dpt:$port" \
| (
while read header to dest rest; do
try "$dest" && let COUNT=$COUNT+1 || remove "$dest"
done; echo $COUNT
)`"
# any job left?
[ "$COUNT" = 0 ] || exit
for ip in "$IP_W" "$IP_E"; do
try "$ip" && let COUNT=$COUNT+1 && add "$ip" && break
done
# any job still left?
[ "$COUNT" = 0 ] || exit
# safety net: add via wifi if nothing else currently possible
add "$IP_W"
_______________________________________________
Sysadmins mailing list
[email protected]
https://lists.altlinux.org/mailman/listinfo/sysadmins
