#! /bin/sh
# usage: coraid-update {update file} {AoE target}
# coraid-update depends upon sysfs mounted on /sys

# The destination must be,
#   1) an AoE target ready for I/O, and
#   2) not too big to be an update target
#
# Later, when CORAID appliances mark update targets with special ATA
# device identify content or special target content, a prompt should
# be added after the check of the target's size if the identifying
# content is not detected.
# 
# The update file must either, 
#   1) be an SR tarc file that looks OK to the local tar, or
#   2) any file not ending in ".tarc".

# size of update LUN in /proc/partitions is 40000
max=70000

usage="usage: coraid-update {update file} {AoE device}"
if test "$#" != 2; then
	echo "$usage" 1>&2
	exit 1
fi
update="$1"
ulb="$2"

# if it's an update target, it should be in `aoe-stat`
aoe-stat | awk -vt="`basename $ulb`" '
BEGIN{fail=1}
$1==t{fail=0}
END{exit fail}' || {
	exec 1>&2
	echo "coraid-update Error: \"$ulb\" is not an AoE target"
	echo "$usage"
	exit 1
}

# it should have a size no larger than $max in /proc/partitions
t="`echo $ulb | sed 's!^/dev/!!'`"
awk -vt="$t" '$NF==t{print $3}' /proc/partitions |
awk -vhi=$max -vdev="$ulb" '
BEGIN{
	err = "could not get size of " dev
} {
	err = "none"
	if ($1 > hi) {
		err = dev " is too large to be an update target"
		exit
	}
} END{
	if (err != "none") {
		print "Error coraid-update: " err > "/dev/stderr"
		exit 1
	}
	exit 0
}' || exit 1

# this test should be removed when it is performed on the appliance
# 
# For a 2734080-byte tarc file, an incomplete file of 2727450 bytes passes
# this test, but one of 2727400 does not.  So this test isn't fullproof.
# 
if test "`echo \"$update\" | grep '\.tarc$'`"; then
	tar tf "$update" > /dev/null 2>&1 || {
		exec 1>&2
		echo "coraid-update Error: \"$update\" does not appear to be a valid tarc file"
		exit 1
	}
fi
if test ! -r "$update"; then
	echo "coraid-update Error: \"$update\" is not readable" 1>&2
	exit 1
fi

# send it over and complain on error
if ! dd if="$update" of="$ulb" 2> /dev/null || ! sync; then
	exec 1>&2
	echo "coraid-update Error: could not successfully write \"$update\" to \"$ulb\""
	exit 1
fi