Add ability to specify existing tap interface in test-machine

Also, create new tap as tap9 instead of tap0.

1 files changed, 27 insertions, 12 deletions

diff --git a/test-machine b/test-machine
index 933a52e..3d55d94 100755
--- a/test-machine
+++ b/test-machine
@@ -6,6 +6,9 @@
 #   Network adapter to use, for example, virtio-net-pci (default), e1000,
 #   or vmxnet3.
 #
+# -t <tap>
+#   Existing tap interface to use instead of creating a new one (as tap9).
+#
 usage="usage: $0 [-n <nic>] <machine-dir> [<qemu-option>...]"
 
 owd="$(pwd)"
@@ -15,7 +18,13 @@ set -o errtrace # Trap in functions.
 function info () { echo "$*" 1>&2; }
 function error () { info "$*"; exit 1; }
 
+br=br0
+mac="de:ad:be:ef:b8:da"
+
+kvm=(qemu-system-x86_64 -enable-kvm)
+
 nic=virtio-net-pci
+etap=
 
 while [ "$#" -gt 0 ]; do
   case "$1" in
@@ -24,6 +33,11 @@ while [ "$#" -gt 0 ]; do
       nic="$1"
       shift
       ;;
+    -t)
+      shift
+      etap="$1"
+      shift
+      ;;
     *)
       break
       ;;
@@ -38,17 +52,16 @@ if [ -z "$dir" ]; then
   error "missing machine directory"
 fi
 
-br=br0
-mac="de:ad:be:ef:b8:da"
-kvm=(qemu-system-x86_64 -enable-kvm)
-
-tap=tap0
-
-sudo ip tuntap delete "$tap" mode tap || true
-sudo ip tuntap add "$tap" mode tap user "$(whoami)"
-sudo ip link set "$tap" up
-#sleep 0.5s
-sudo ip link set "$tap" master "$br"
+if [ -z "$etap" ]; then
+  tap=tap9
+  sudo ip tuntap delete "$tap" mode tap || true
+  sudo ip tuntap add "$tap" mode tap user "$(whoami)"
+  sudo ip link set "$tap" up
+  #sleep 0.5s
+  sudo ip link set "$tap" master "$br"
+else
+  tap="$etap"
+fi
 
 "${kvm[@]}" \
   -m 8G \
@@ -84,7 +97,9 @@ sudo ip link set "$tap" master "$br"
 #-vnc "unix:$dir/vnc" \
 #-monitor "unix:$dir/monitor,server,nowait"
 
-sudo ip tuntap delete "$tap" mode tap
+if [ -z "$etap" ]; then
+  sudo ip tuntap delete "$tap" mode tap
+fi
 
 exit 0