TtapNetQemu

#!/sbin/openrc-run
#
# OpenRc Script to create a service that can configure a Internal or Host-Only Network
# it create tun/tap and bridge interfaces, you'll able to use them how do you like
#
# INSTRUCTIIONS: 
# 1- create file /etc/ttapnetqemu/network.conf put follow lines
#
#	mode=hostonly|inet #hostonly -> Host Only Network or inet -> Internal Network
#	host_numbers=2 #Number of hosts to configure. it create same number of tun/tap and bro interface depending to mode
#	kvm_group=kvm #Specify kvm user group, it necessary to grant permissions on tap interfaces
#
# 2- then rc-service start you can run
#		qemu-system-x86_64 -netdev tap,id=YOUR_IDNET,ifname=TAP_INTERFACE,script=no
#               -device e1000,netdev=net1,mac=XX:XX:XX:XX:XX:XX -enable-kvm -daemonize
#

CONF_FOLDER="/etc/ttapnetqemu/network.conf";
DE_KEYVALUE_CONF="="

depend(){
   need net 
}

start(){
 ebegin "Configuring Qemu Network"
 if [[ -f $CONF_FOLDER ]]; then
   MODE=$(grep "mode" $CONF_FOLDER | awk -F $DE_KEYVALUE_CONF '{print $2}');
   NUMBER_TAPIFACES=$(grep "host_numbers" $CONF_FOLDER | awk -F $DE_KEYVALUE_CONF '{print $2}');
   KVM_GROUP=$(grep "kvm_group" $CONF_FOLDER | awk -F $DE_KEYVALUE_CONF '{print $2}');

   #Adding all tun/tap interfaces
   case $MODE in
	"hostonly" )
	  einfo "Creating topology Host-Only Network";
	  for iface in $(seq 1 1 $NUMBER_TAPIFACES) ;
          do
            ip tuntap add dev "tap$iface" mode tap group $KVM_GROUP;
            ip link set dev "tap$iface" up promisc on;
            ip addr add 0.0.0.0 dev "tap$iface";
            ip link add "br$iface" type bridge;
            ip link set "br$iface" up;
            ip link set "tap$iface" master "br$iface";
	    echo 0 > "/sys/class/net/br$iface/bridge/stp_state";
            ip addr add "192.168.$iface.1/24" dev "br$iface";
          done;
		;;
	"inet" )
          einfo "Creating topology Internal Network";
	  ip link add br0 type bridge;
          ip link set br0 up;
          echo 0 > "/sys/class/net/br0/bridge/stp_state";
          ip addr add 10.0.0.1/24 dev br0;
          for iface in $(seq 1 1 $NUMBER_TAPIFACES) ;
	  do
	    ip tuntap add dev "tap$iface" mode tap group $KVM_GROUP;
            ip link set dev "tap$iface" up promisc on;
            ip addr add 0.0.0.0 dev "tap$iface";
            ip link set "tap$iface" master br0;
	  done;
		;;
        esac
 else
	return 1;
 fi
 eend $?
}

stop(){

 ebegin "Removing all Tun/Tap and bridge interfaces"
 #Check if qemu is running
 pgrep "qemu-system" &>/dev/null;

 if [[ $? -ne 0 ]]; then
   #Get all tuntap and bridge interfaces
   for iface in $({(ip -br tuntap); (ip -br link show type bridge);} | awk -F '[: ]' '{print $1}') ; do
      ip link set $iface down;
      ip link del $iface;
   done;
 else
	return 1;
 fi
 eend $? 
}