-#################### bridge initialization
-function create_bridge_if_needed() {
-
- # turn on verbosity
- set -x
-
- # already created ? - we're done
- ip addr show $PUBLIC_BRIDGE >& /dev/null && {
- echo "Bridge already set up - skipping create_bridge_if_needed"
- return 0
- }
-
- # find out the physical interface to bridge onto
- if_lan=$(discover_interface)
-
- ip addr show $if_lan &>/dev/null || {
- echo "Cannot use interface $if_lan - exiting"
- exit 1
- }
-
- #################### bride initialization
- check_yum_installed bridge-utils
-
- echo "========== $COMMAND: entering create_bridge - beg"
- hostname
- uname -a
- ip addr show
- ip route
- echo "========== $COMMAND: entering create_bridge - end"
-
- # disable netfilter calls for bridge interface (they cause panick on 2.6.35 anyway)
- #
- # another option would be to accept the all forward packages for
- # bridged interface like: -A FORWARD -m physdev --physdev-is-bridged -j ACCEPT
- sysctl net.bridge.bridge-nf-call-iptables=0
- sysctl net.bridge.bridge-nf-call-ip6tables=0
- sysctl net.bridge.bridge-nf-call-arptables=0
-
-
- #Getting host IP/masklen
- address=$(ip addr show $if_lan | grep -v inet6 | grep inet | head --lines=1 | awk '{print $2;}')
- [ -z "$address" ] && { echo "ERROR: Could not determine IP address for $if_lan" ; exit 1 ; }
-
- broadcast=$(ip addr show $if_lan | grep -v inet6 | grep inet | head --lines=1 | awk '{print $4;}')
- [ -z "$broadcast" ] && echo "WARNING: Could not determine broadcast address for $if_lan"
-
- gateway=$(ip route show | grep default | awk '{print $3;}')
- [ -z "$gateway" ] && echo "WARNING: Could not determine gateway IP"
-
-
- # creating the bridge
- echo "Creating bridge PUBLIC_BRIDGE=$PUBLIC_BRIDGE"
- brctl addbr $PUBLIC_BRIDGE
- brctl addif $PUBLIC_BRIDGE $if_lan
- echo "Activating promiscuous mode if_lan=$if_lan"
- ip link set $if_lan up promisc on
- sleep 2
- # rely on dhcp to re assign IP..
- echo "Starting dhclient on $PUBLIC_BRIDGE"
- dhclient $PUBLIC_BRIDGE
- sleep 1
-
- #Reconfigure the routing table
- echo "Configuring gateway=$gateway"
- ip route add default via $gateway dev $PUBLIC_BRIDGE
- ip route del default via $gateway dev $if_lan
- # at this point we have an extra route like e.g.
- ## ip route show
- #default via 138.96.112.250 dev br0
- #138.96.112.0/21 dev em1 proto kernel scope link src 138.96.112.57
- #138.96.112.0/21 dev br0 proto kernel scope link src 138.96.112.57
- #192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1
- route_dest=$(ip route show | grep -v default | grep "dev $PUBLIC_BRIDGE" | awk '{print $1;}')
- ip route del $route_dest dev $if_lan
-
- echo "========== $COMMAND: exiting create_bridge - beg"
- ip addr show
- ip route show
- echo "========== $COMMAND: exiting create_bridge - end"
-
- # for safety
- sleep 3
- return 0
-