skip bridge interface when guessing physical interface

[tests.git] / system / template-qemu / qemu-bridge-init

diff --git a/system/template-qemu/qemu-bridge-init b/system/template-qemu/qemu-bridge-init
index 5c03280..d182557 100755 (executable)
--- a/system/template-qemu/qemu-bridge-init
+++ b/system/template-qemu/qemu-bridge-init
@@ -1,11 +1,12 @@
 #!/bin/bash
 
+# Thierry Parmentelat <thierry.parmentelat@inria.fr>
+# Copyright (C) 2010 INRIA 
+#
 # Establishment of a runtime environment for a
 # virtual  machine  under QEMU, This script allows the host box
 # to share its network connection with qemu-based guests
 #
-# Author: Amine chaoui
-#
 
 COMMAND=$(basename $0)
 cd $(dirname $0)
@@ -15,11 +16,50 @@ set -x
 
 # constant
 INTERFACE_BRIDGE=br0
-# Default Value
-INTERFACE_LAN=eth0
 
+#################### compute INTERFACE_LAN
+# use /proc/net/dev instead of a hard-wired list
+function gather_interfaces () {
+    python <<EOF
+for line in file("/proc/net/dev"):
+    if ':' not in line: continue
+    ifname=line.replace(" ","").split(":")[0]
+    if ifname.find("lo")==0: continue
+    if ifname.find("br")==0: continue
+    if ifname.find("virbr")==0: continue
+    if ifname.find("tap")==0: continue
+    print ifname
+EOF
+}
+    
+function discover_interface () {
+    for ifname in $(gather_interfaces); do
+       ip link show $ifname | grep -qi 'state UP' && { echo $ifname; return; }
+    done
+    # still not found ? that's bad
+    echo unknown
+}
+INTERFACE_LAN=$(discover_interface)
+echo Using physical interface $INTERFACE_LAN
+
+####################
 # Fonction de mise en place du pont
-start () {
+function start () {
+
+    echo "========== $COMMAND: entering start - beg"
+    hostname
+    uname -a
+    ifconfig
+    netstat -rn
+    echo "========== $COMMAND: entering start - end"
+
+    # disable netfilter calls for bridge interface (they cause panick on 2.6.35 anyway)
+    #
+    # another option would be to accept the all forward packages for
+    # bridged interface like: -A FORWARD -m physdev --physdev-is-bridged -j ACCEPT
+    sysctl net.bridge.bridge-nf-call-iptables=0
+    sysctl net.bridge.bridge-nf-call-ip6tables=0
+    sysctl net.bridge.bridge-nf-call-arptables=0
 
     # take extra arg for ifname, if provided
     [ -n "$1" ] && { INTERFACE_LAN=$1; shift ; }
@@ -29,7 +69,7 @@ start () {
 
     #if we have already configured the same host_box no need to do it again
     /sbin/ifconfig $INTERFACE_BRIDGE &> /dev/null && {
-       echo "Interface bridge $INTERFACE_BRIDGE already exist."
+       echo "Bridge interface $INTERFACE_BRIDGE already set up - $COMMAND start exiting"
        exit 0
     }
     /sbin/ifconfig $INTERFACE_LAN &>/dev/null || {
@@ -52,9 +92,9 @@ start () {
     echo "Starting udev ..."
     /sbin/udevd restart
     if modprobe kqemu &> /dev/null ; then
-       echo "kqemu loadded"
+       echo "(bridge-init) kqemu loaded"
     else
-       echo "WARNING : Could not modprobe kqemu"
+       echo "(bridge-init) WARNING : Could not modprobe kqemu"
     fi
     #Loading the tun/tap model
     if modprobe tun ; then
@@ -84,14 +124,23 @@ start () {
     echo "Configuring gateway=$gateway"
     route add default gw $gateway
 
+    echo "========== $COMMAND: exiting start - beg"
+    ifconfig
+    netstat -rn
+    echo "========== $COMMAND: exiting start - end"
 }
 
 #Adding a new interface to the bridge: this is used by qemu-ifup 
-add () {
+function add () {
 
     [[ -z "$@" ]] && { echo "Usage: $COMMAND add ifname" ; exit 1 ; }
     INTERFACE_LAN=$1; shift
 
+    echo "========== $COMMAND: entering add - beg"
+    ifconfig
+    netstat -rn
+    echo "========== $COMMAND: entering add - end"
+
     echo "Activating link for $INTERFACE_LAN..."
     /sbin/ip link set $INTERFACE_LAN up
     sleep 1
@@ -111,13 +160,19 @@ add () {
     ./iptables.py iptables.pre iptables.post $IP
     iptables-restore < iptables.post
 
+    echo "========== $COMMAND: exiting add - beg"
+
+    ifconfig
+    netstat -rn
+
     echo "Installed iptables"
     iptables-save
     
+    echo "========== $COMMAND: exiting add - end"
 }
 
 #Stop the bridge and restore the original setting
-stop () {
+function stop () {
     # take extra arg for ifname, if provided
     [ -n "$1" ] && { INTERFACE_LAN=$1; shift ; }
 
@@ -125,7 +180,7 @@ stop () {
     type -p brctl &> /dev/null || { echo "brctl not found, please install bridge-utils" ; exit 1 ; }
 
     /sbin/ifconfig $INTERFACE_BRIDGE &> /dev/null || {
-       echo "Interface bridge $INTERFACE_BRIDGE does not exist."
+       echo "Bridge interface $INTERFACE_BRIDGE does not exist - $COMMAND stop exiting"
        exit 0
     }
     brctl delif $INTERFACE_BRIDGE $INTERFACE_LAN