Bug#535008: configure_networking: support BOOTIF variable set by pxelinux

[Vagrant Cascadian <vagrant@freegeek.org>]

On Sun, Jun 28, 2009 at 11:51:32PM +0100, Ben Hutchings wrote:
> On Sun, 2009-06-28 at 14:50 -0700, Vagrant Cascadian wrote:
> > Package: initramfs-tools
> > Version: 0.93.3
> > Severity: wishlist
> > Tags: patch
> > 
> > when booting thin clients with multiple network cards, initramfs-tools/ipconfig
> > have a hard time figuring out which interface to use. attached is a patch which
> > sets DEVICE to the interface matching the mac address that pxelinux passes when
> > using the IPAPPEND 2 or 3 options.
> 
> This sounds reasonable, but your patch makes unnecessary use of several
> commands.
> 
> > diff --git a/scripts/functions b/scripts/functions
> > index 77de8f3..ec0ffd2 100644
> > --- a/scripts/functions
> > +++ b/scripts/functions
> > @@ -258,6 +258,19 @@ parse_numeric() {
> >  
> >  configure_networking()
> >  {
> > +
> > +	# pxelinux sets BOOTIF to a value based on the mac address of the network
> > +	# card used to PXE boot, so use this value for DEVICE rather than a
> > +	# hard-coded device name from initramfs.conf. this facilitates network
> > +	# booting when machines may have multiple network cards.
> > +	if [ -n "${BOOTIF}" ]; then
> > +		normal_mac=$(echo $BOOTIF | sed -e 's,^01-,,g' -e 's,-,:,g' | tr [a-z] [A-Z])
> 
> You can use sed's y/// command instead of piping to tr.
> 
> > +		new_device=$(ifconfig -a | awk "/$normal_mac/"'{print $1}')
> [...]
> 
> You can use the files /sys/class/net/*/address instead of ifconfig.

thanks for the suggestions, updated patch:

diff --git a/scripts/functions b/scripts/functions
index 77de8f3..f99e779 100644
--- a/scripts/functions
+++ b/scripts/functions
@@ -258,6 +258,25 @@ parse_numeric() {
 
 configure_networking()
 {
+
+	# pxelinux sets BOOTIF to a value based on the mac address of the
+	# network card used to PXE boot, so use this value for DEVICE rather
+	# than a hard-coded device name from initramfs.conf. this facilitates
+	# network booting when machines may have multiple network cards.
+	# pxelinux sets BOOTIF to 01-$mac_address
+	if [ -n "${BOOTIF}" ]; then
+		bootif_mac=$(echo ${BOOTIF#*-} | sed -e 'y,-,:,')
+		for device in /sys/class/net/* ; do
+			if [ -f "$device/address" ]; then
+				current_mac=$(cat "$device/address")
+				if [ "$bootif_mac" = "$current_mac" ]; then
+					DEVICE=${device##*/}
+					break
+				fi
+			fi
+		done
+	fi
+
 	# networking already configured thus bail out
 	[ -n "${DEVICE}" ] && [ -e /tmp/net-"${DEVICE}".conf ] && return 0
 

live well,
  vagrant