rumprun: Generate random MAC addresses for qemu/kvm

Each unikernel on kvm/qemu gets the same MAC address, making them
unusable in bridged configurations.

diff --git a/app-tools/rumprun b/app-tools/rumprun
index d224809a5be3d12ba41f4857732f27079c3ca7a8..71a130584f50242143705141ecae8999f6aaf248 100755 (executable)
--- a/app-tools/rumprun
+++ b/app-tools/rumprun
@@ -159,8 +159,10 @@ createif_qemu ()
        scratch="${1#*,}"
        ifbasename="${scratch%%,*}"
        qemuargs="${scratch#*,}"
+       # 52:54:00 is QEMU registered OUI
+       ifmac="52:54:00$(od -N 3 -A n -t x1 /dev/urandom | tr ' ' :)"
 
-       opt_netif="${opt_netif} -net nic,model=virtio ${qemuargs}"
+       opt_netif="${opt_netif} -net nic,model=virtio,macaddr=${ifmac} ${qemuargs}"
        eval ${iftag}2ifname=${ifbasename}${nindex}
        eval ${iftag}2cloner=false
        nindex=$(expr $nindex + 1)