[PATCH] tools: Fix network-bridge to work with Gentoo (version 2)

[Jon Mason <jdmason@us.ibm.com>]

This patch fixes domU networking in Gentoo.  The change to ifup/ifdown
(which isn't availabe in Gentoo) prevents the bridge from being setup
correctly.  The patch below checks if ifup is avaiable, and if not
starts the Gentoo networking scripts.

This new version includes shell functions where distro specific options
may be handled (per Ian's suggestion).  

Signed-off-by: Jon Mason <jdmason@us.ibm.com>

# HG changeset patch
# User root@pentium4
# Node ID 6de75791e5a54b8eb093c6630efb68f896c16fa3
# Parent  00037ba13f0bb8efe4b2c3efe40200eac21c68dd

Fix network-bridge to work with Gentoo

diff -r 00037ba13f0b -r 6de75791e5a5 tools/examples/network-bridge
--- a/tools/examples/network-bridge	Tue Oct  4 17:23:58 2005
+++ b/tools/examples/network-bridge	Tue Oct  4 23:42:28 2005
@@ -54,6 +54,32 @@
 antispoof=${antispoof:-no}
 
 echo "*network $OP bridge=$bridge netdev=$netdev antispoof=$antispoof" >&2
+
+# Usage: eth_down interface
+eth_down() {
+	local rc
+	local eth=$1
+	ifdown=$(which ifdown 2>/dev/null)
+	if [ -n "$ifdown" ]; then
+		$ifdown ${eth}; rc=$?
+	else
+		/etc/init.d/net.${eth} stop; rc=$?
+	fi
+	return $rc
+}
+
+# Usage: eth_up interface
+eth_up() {
+	local rc
+	local eth=$1
+	ifdown=$(which ifup 2>/dev/null)
+	if [ -n "$ifup" ]; then
+		$ifup ${eth}; rc=$?
+	else
+		/etc/init.d/net.${eth} start; rc=$?
+	fi
+	return $rc
+}
 
 # Usage: transfer_addrs src dst
 # Copy all IP addresses (including aliases) from device $src to device $dst.
@@ -177,7 +203,7 @@
 
     if ifconfig veth0 2>/dev/null | grep -q veth0 ; then
 	mac=`ifconfig ${netdev} | grep HWadd | sed -e 's/.*\(..:..:..:..:..:..\).*/\1/'`
-	if ! ifdown ${netdev} ; then
+	if ! eth_down ${netdev} ; then
 		# if ifup didn't work, see if we have an ip= on cmd line
 		if egrep 'ip=[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+:' /proc/cmdline ; 
 		then
@@ -197,7 +223,7 @@
 	ip link set ${bridge} up
 	ip link set vif0.0 up
 	ip link set p${netdev} up
-	if ! ifup ${netdev} ; then
+	if ! eth_up ${netdev} ; then
 		if [ ${kip} ] ; then
 			# use the addresses we grocked from /proc/cmdline	
 			ifconfig ${netdev} ${kip} 
@@ -238,7 +264,7 @@
         ip link set peth0 name eth0
         ifconfig ${bridge} down
         brctl delbr ${bridge}
-        ifup eth0
+        eth_up eth0
 
     else
         transfer_routes ${bridge} ${netdev}