configure_networking: support BOOTIF variable set by pxelinux

updated patch against current master, using only shell, and with a cleaner
method to convert BOOTF to a typical mac address.

(closes: #567540)

Signed-off-by: maximilian attems <maks@debian.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/scripts/functions b/scripts/functions
index c34dd4a..60cfc11 100644
--- a/scripts/functions
+++ b/scripts/functions
@@ -258,6 +258,42 @@ parse_numeric() {
 
 configure_networking()
 {
+	if [ -n "${BOOTIF}" ]; then
+		# pxelinux sets BOOTIF to a value based on the mac address of the
+		# network card used to PXE boot, so use this value for DEVICE rather
+		# than a hard-coded device name from initramfs.conf. this facilitates
+		# network booting when machines may have multiple network cards.
+		# pxelinux sets BOOTIF to 01-$mac_address
+
+		# strip off the leading "01-", which isn't part of the mac
+		# address
+		temp_mac=${BOOTIF#*-}
+
+		# convert to typical mac address format by replacing "-" with ":"
+		bootif_mac=""
+		IFS='-'
+		for x in $temp_mac ; do
+			if [ -z "$bootif_mac" ]; then
+				bootif_mac="$x"
+			else
+				bootif_mac="$x:$bootif_mac"
+			fi
+		done
+		unset IFS
+
+		# look for devices with matching mac address, and set DEVICE to
+		# appropriate value if match is found.
+		for device in /sys/class/net/* ; do
+			if [ -f "$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