1.1 --- a/tools/examples/network-bridge	Mon Nov 14 12:28:47 2005 +0100
     1.2 +++ b/tools/examples/network-bridge	Tue Nov 15 15:54:51 2005 +0100
     1.3 @@ -138,6 +138,23 @@ transfer_routes () {
     1.4  }" | sh -e
     1.5  }
     1.6  
     1.7 +
     1.8 +##
     1.9 +# link_exists interface
    1.10 +#
    1.11 +# Returns 0 if the interface named exists (whether up or down), 1 otherwise.
    1.12 +#
    1.13 +link_exists()
    1.14 +{
    1.15 +    if ip link show "$1" >&/dev/null
    1.16 +    then
    1.17 +        return 0
    1.18 +    else
    1.19 +        return 1
    1.20 +    fi
    1.21 +}
    1.22 +
    1.23 +
    1.24  # Usage: create_bridge bridge
    1.25  create_bridge () {
    1.26      local bridge=$1
    1.27 @@ -193,8 +210,12 @@ op_start () {
    1.28  	return
    1.29      fi
    1.30  
    1.31 -    if ! ip link show 2>/dev/null | grep -q "^[0-9]*: ${vdev}"; then
    1.32 -        echo "
    1.33 +    if ! link_exists "$vdev"; then
    1.34 +        if link_exists "$pdev"; then
    1.35 +            # The device is already up.
    1.36 +            return
    1.37 +        else
    1.38 +            echo "
    1.39  Link $vdev is missing.
    1.40  This may be because you have reached the limit of the number of interfaces
    1.41  that the loopback driver supports.  If the loopback driver is a module, you
    1.42 @@ -202,12 +223,13 @@ may raise this limit by passing it as a 
    1.43  driver is compiled statically into the kernel, then you may set the parameter
    1.44  using loopback.nloopbacks=<N> on the domain 0 kernel command line.
    1.45  " >&2
    1.46 -        exit 1
    1.47 +            exit 1
    1.48 +        fi
    1.49      fi
    1.50  
    1.51      create_bridge ${bridge}
    1.52  
    1.53 -    if ip link show ${vdev} 2>/dev/null >/dev/null; then
    1.54 +    if link_exists "$vdev"; then
    1.55  	mac=`ip link show ${netdev} | grep 'link\/ether' | sed -e 's/.*ether \(..:..:..:..:..:..\).*/\1/'`
    1.56  	preiftransfer ${netdev}
    1.57  	transfer_addrs ${netdev} ${vdev}
    1.58 @@ -260,11 +282,11 @@ op_stop () {
    1.59      if [ "${bridge}" == "null" ]; then
    1.60  	return
    1.61      fi
    1.62 -    if ! ip link show ${bridge} >/dev/null 2>&1; then
    1.63 +    if ! link_exists "$bridge"; then
    1.64  	return
    1.65      fi
    1.66  
    1.67 -    if ip link show ${pdev} 2>/dev/null >/dev/null; then
    1.68 +    if link_exists "$pdev"; then
    1.69  	ip link set dev ${vif0} down
    1.70  	mac=`ip link show ${netdev} | grep 'link\/ether' | sed -e 's/.*ether \(..:..:..:..:..:..\).*/\1/'`
    1.71  	transfer_addrs ${netdev} ${pdev}