multiwan 脚本

以下为校区ACM实验室多拨脚本，使用了macvlan模块，具体策略路由和连接标记等思路就不解释了。

 #! /bin/bash

 getip() {
     ifconfig $ |grep -o -e 'inet addr:[^ ]*' | grep -o -e '[^:]*$'
 }

 ip link add link br0 address ::3e:aa:bb:xx dev veth0 type macvlan
 ip link add link br0 address ::3e:aa:bb:yy dev veth1 type macvlan
 ip link add link br0 address ::3e:aa:bb:zz dev veth2 type macvlan
 dhclient veth0 veth1 veth2

 iptables -t mangle -N PREROUTING_INPUT
 iptables -t mangle -N POSTROUTING_GUESS

 IPROUTE_ARGS=""

 for((i=;i<;++i)); do
     for ((j=;j<;++j)); do
         IP="$(getip veth$i)"
         [[ -n $IP ]] && break
         sleep
     done
     [[ -z $IP ]] && continue

     SUBNET="${IP%.[0-9]*}"
     GATEWAY="${SUBNET}.254"

     iptables -t mangle -A PREROUTING_INPUT -i veth$i -j MARK --set-mark $[$i+0x100]
     iptables -t mangle -A PREROUTING_INPUT -i veth$i -j ACCEPT

     iptables -t mangle -A POSTROUTING_GUESS -o veth$i -j MARK --set-mark $[$i+0x100]

     ip route append "${SUBNET}.0/24" dev veth$i src $IP table default &&
     ip route del "${SUBNET}.0/24" dev veth$i table main

     ip route add default via $GATEWAY dev veth$i table veth$i

     ip rule add from $IP table veth$i
     ip rule add to $IP table veth$i
     ip rule add fwmark $[$i+0x100] table veth$i
     IPROUTE_ARGS=$IPROUTE_ARGS" nexthop via "$GATEWAY" dev veth"$i" weight 1"
 done

 # Connections can not change link, get link from saved mark, even for
 # incoming traffic
 iptables -t mangle -A PREROUTING -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark

 # Select link if not selected yet. NEW state can match conns even after reboot.
 # Even for incoming connections destined to local address.
 iptables -t mangle -A PREROUTING -m state --state NEW -j PREROUTING_INPUT

 # Connection has no mark from PREROUTING, see which link is selected by routing
 iptables -t mangle -A POSTROUTING -m state --state NEW -m mark --mark  -j POSTROUTING_GUESS

 # Save mark in conntrack when connection is created
 iptables -t mangle -A POSTROUTING -m conntrack --ctstate NEW -j CONNMARK --save-mark

 ip route replace default scope global table default equalize $IPROUTE_ARGS

 # Remove default route from table main
 ip route del default table main

 # Add main table at top.
 ip rule add from all lookup main