for nested kvm, increment the MAC address

1 files changed, 14 insertions, 1 deletions

diff --git a/src/qemu.sh b/src/qemu.sh
index 2ae982d..130b688 100755
--- a/src/qemu.sh
+++ b/src/qemu.sh
@@ -30,7 +30,20 @@ kcmdline_CDROM='boot=samizdat components quiet splash'
 kcmdline_CDROM_NET="${kcmdline_CDROM} nbdroot=,${nbd_filename}, nbddev=/dev/nbd0 ip=dhcp"
 kcmdline_NET="${kcmdline_CDROM_NET} netkeys"
 
-MAC='52-54-00-12-34-56'
+find_mac()
+{
+  start_mac=$1
+  for mac in $(ip link show | grep link/ether | (read _ mac _; echo $mac | tr : -)); do
+    if [ "${mac%??}" = "${start_mac%??}" ]; then
+      prefix=${mac%??}
+      suffix=$(printf %x $(( 0x${mac##*-} + 1 )))
+      MAC=${prefix}${suffix}
+      return
+    fi
+  done
+  MAC=$start_mac
+}
+find_mac 52-54-00-12-34-56
 
 kcmdline_BOOTIF="BOOTIF=01-$MAC"