From c3f79834be3fe862388432d01f15f727c8b7cd7c Mon Sep 17 00:00:00 2001
From: Jeremy Kerr <jk@ozlabs.org>
Date: Mon, 6 May 2013 15:54:23 +0800
Subject: [PATCH 1/1] pb-udhcpc: Look for more boot options

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
---
 utils/pb-udhcpc | 84 +++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 82 insertions(+), 2 deletions(-)

diff --git a/utils/pb-udhcpc b/utils/pb-udhcpc
index ff23178..808f12a 100644
--- a/utils/pb-udhcpc
+++ b/utils/pb-udhcpc
@@ -9,16 +9,96 @@
 PBOOT_USER_EVENT_SOCKET="/tmp/petitboot.ev"
 log="/var/log/petitboot/pb-udhcpc.log"
 
+resolve_url() {
+	file="$1"
+
+	# URL? use as-is.
+	tmp=${file#://*}
+	if [ "$tmp" != "$file" ]
+	then
+		echo "$file"
+	fi
+
+	# Otherwise, TFTP using an appropriate host. Start with the
+	# DHCP 'tftp' option:
+	host=${tftp}
+
+	# next, try the DHCP next-server-address
+	[ -z "$host" ] && host=${siaddr}
+
+	# finally, use the DHCP server we got this lease from:
+	[ -z "$host" ] && host=${serverid}
+
+	echo "tftp://$host/$file"
+}
+
+do_pxe() {
+	basedir=$1
+
+	params="conf@/net/${interface} method=dhcp"
+
+	# first, try by MAC
+	mac=$(cat /sys/class/net/$interface/address)
+	pb-event $params url=$basedir/$mac
+
+	# try decreasing fragments of IP lease
+	ip_hex=$(printf '%02X%02X%02X%02X' $(echo $ip | tr '.' ' '))
+	for i in $(seq 8 -1 1)
+	do
+		frag=${hex_ip:0:$i}
+		pb-event $params url=$basedir/$frag
+	done
+
+	# last, use default
+	pb-event $params url=$basedir/default
+}
+
 pb_add () {
+
+	# Look for an explicit config file location in the DHCP config-file
+	# parameter
+	if [ -n ${conffile} ]
+	then
+		url=$(resolve_url ${conffile})
+		pb-event conf@/net/${interface} url=$url method=dhcp
+		return
+	fi
+
+	# Otherwise, we'll need the boot-file parameter. Looks like udhcpc
+	# will give us different names, depending if the parameter was in
+	# the header, or specified by options
+	[ -n "$bootfile" ] && bootfile=${boot_file}
+
+	if [ -z "$bootfile" ]
+	then
+		return
+	fi
+
+	# PXE behaviour is to download the config file based on a file
+	# structure relative to the pxelinux binary
+	file=${bootfile}
+	[ -z "$file" ] && file=${boot_file}
+	if [ -n "$file" ]
+	then
+		basedir=${file%%/*}
+		do_pxe $basedir
+	fi
+
+	# Finally, add an option for the boot_file parameter
 	k_server_ip=${rootpath%%:*}
 	k_root_dir=${rootpath#*:}
 
-	[ ${k_server_ip} != ${rootpath} ] || k_server_ip=${serverid}
+	args=
+	if [ -n $rootpath ]
+	then
+		[ ${k_server_ip} != ${rootpath} ] || k_server_ip=${serverid}
+		args="root=/dev/nfs ip=any nfsroot=${k_server_ip}:${k_root_dir}"
+	fi
 
 	pb-event add@/net/${interface} \
 		name=netboot \
 		image=tftp://${siaddr}/${boot_file} \
-		args="root=/dev/nfs ip=any nfsroot=${k_server_ip}:${k_root_dir}"
+		args="$args"
 }
 
 pb_remove () {
-- 
2.39.2