bridge

linux下用PCMCIA无线网卡虚拟无线AP的程序源码

#!/bin/sh


EXITCODE=1
case "$1" in
    start)
	echo "Starting BRIDGING services:"

	# fixme: move eth0 stuff to wired
	ifconfig eth0 up
	    
	WLANS=`ifconfig -a | cut -d ' ' -f 1 | grep wlan`
	ETHS=`ifconfig -a | cut -d ' ' -f 1 | grep eth`

	brctl addbr br0
	brctl sethello br0 2 # must keep this below fd
	# maxage - length of time between configuration messages
	# (hellos) before a bridge decides that a port is no longer
	# reachable.  we'll set it to the time it takes an ap to
	# reboot.  the longer it is, the less we are affected by
	# unnecessary spanning tree recalculations
	brctl setmaxage br0 60 
	brctl setfd br0 4
	brctl setbridgeprio br0 100
	
	# wlans must be first so the bridge takes the
	# MAC address of the wlan
	for i in $WLANS $ETHS ; do
	    brctl addif br0 $i
	done
	
	ifconfig br0 up

	# see if any packets received on eth0 interface
	#ETH_PKTS=`grep eth0 /proc/net/dev| cut -d " " -f 5`
	#if [ "$ETH_PKTS" -ne "0" ] ; then
	#    # if eth0 is active lower bridge priority
	#    # (we want the wired bridges to be root)
	#    echo "lowering bridge priority"
	#    brctl setbridgeprio br0 0
	#fi
	
	EXITCODE=0
	;;
	
    stop)
	echo "Shutting down BRIDGING services:"

        WLANS=`brctl show | sed -n 's/.*\(wlan.*\).*/\1/p'` 
	ETHS=`brctl show | sed -n 's/.*\(eth.*\).*/\1/p'`

	# teardown the bridge
	ifconfig br0 down

	for i in $WLANS $ETHS ; do
	    brctl delif br0 $i
	done

	brctl delbr br0

	EXITCODE=0
	;;

    status)
	echo "Checking BRIDGING service status:"
	EXITCODE=0
	;;
    restart|reload)
	echo "Restarting BRIDGING services:"
	$0 stop
	    sleep 1
	$0 start
	EXITCODE=$?
	;;

    *)
	echo "Usage: $0 {start|stop|status|restart|reload}"
	exit 1;
	;;
esac