base-files: accept gzipped nand sysupgrade images

When firmware images only contained compressed kernels and squashfs roots,
uncompressed tar files were a good option. We are now using UBIFS images,
both raw and tarred, as well as ubinized (full UBI partition) images, all
of which benefit greatly from compression.

For example, a raw ubinized backup taken from a running Askey RT4230W REV6
(such full backups can be restored via the LUCI's sysupgrade UI) is over
400 MB, but compresses to less than 10 MB.

This commit adds support for gzipped versions of all file types already
accepted by the nand sysupgrade mechanism, be them raw or tarred.

Signed-off-by: Rodrigo Balerdi <lanchon@gmail.com>

1 files changed, 55 insertions, 31 deletions

diff --git a/package/base-files/files/lib/upgrade/nand.sh b/package/base-files/files/lib/upgrade/nand.sh
index 19e51c55c0..496e5bf7fb 100644
--- a/package/base-files/files/lib/upgrade/nand.sh
+++ b/package/base-files/files/lib/upgrade/nand.sh
@@ -56,11 +56,11 @@ nand_find_ubi() {
 }
 
 nand_get_magic_long() {
-	dd if="$1" skip=$2 bs=4 count=1 2>/dev/null | hexdump -v -n 4 -e '1/1 "%02x"'
+	(${3}cat "$1" | dd bs=4 "skip=${2:-0}" count=1 | hexdump -v -n 4 -e '1/1 "%02x"') 2> /dev/null
 }
 
 get_magic_long_tar() {
-	( tar xf $1 $2 -O | dd bs=4 count=1 | hexdump -v -n 4 -e '1/1 "%02x"') 2> /dev/null
+	(tar x${3}f "$1" "$2" -O | dd bs=4 count=1 | hexdump -v -n 4 -e '1/1 "%02x"') 2> /dev/null
 }
 
 identify_magic() {
@@ -81,6 +81,9 @@ identify_magic() {
 		"4349"*)
 			echo "combined"
 			;;
+		"1f8b"*)
+			echo "gzip"
+			;;
 		*)
 			echo "unknown $magic"
 			;;
@@ -89,11 +92,15 @@ identify_magic() {
 
 
 identify() {
-	identify_magic $(nand_get_magic_long "$1" "${2:-0}")
+	identify_magic $(nand_get_magic_long "$@")
 }
 
 identify_tar() {
-	identify_magic $(get_magic_long_tar "$1" "$2")
+	identify_magic $(get_magic_long_tar "$@")
+}
+
+identify_if_gzip() {
+	if [ "$(identify "$1")" = gzip ]; then echo -n z; fi
 }
 
 nand_restore_config() {
@@ -258,54 +265,61 @@ nand_upgrade_prepare_ubi() {
 # Write the UBI image to MTD ubi partition
 nand_upgrade_ubinized() {
 	local ubi_file="$1"
+	local gz="$2"
 
 	nand_detach_ubi "$CI_UBIPART" || return 1
 
 	local mtdnum="$( find_mtd_index "$CI_UBIPART" )"
-	ubiformat "/dev/mtd$mtdnum" -y -f "$ubi_file" && ubiattach -m "$mtdnum"
+	${gz}cat "$ubi_file" | ubiformat "/dev/mtd$mtdnum" -y -f - && ubiattach -m "$mtdnum"
 }
 
 # Write the UBIFS image to UBI rootfs volume
 nand_upgrade_ubifs() {
-	local rootfs_length=$( (cat $1 | wc -c) 2> /dev/null)
+	local ubifs_file="$1"
+	local gz="$2"
 
-	nand_upgrade_prepare_ubi "$rootfs_length" "ubifs" "" "" || return 1
+	local ubifs_length=$( (${gz}cat "$ubifs_file" | wc -c) 2> /dev/null)
+
+	nand_upgrade_prepare_ubi "$ubifs_length" "ubifs" "" "" || return 1
 
 	local ubidev="$( nand_find_ubi "$CI_UBIPART" )"
 	local root_ubivol="$(nand_find_volume $ubidev "$CI_ROOTPART")"
-	ubiupdatevol /dev/$root_ubivol -s $rootfs_length $1
+	${gz}cat "$ubifs_file" | ubiupdatevol /dev/$root_ubivol -s "$ubifs_length" -
 }
 
 # Write the FIT image to UBI kernel volume
 nand_upgrade_fit() {
 	local fit_file="$1"
-	local fit_length="$(wc -c < "$fit_file")"
+	local gz="$2"
+
+	local fit_length=$( (${gz}cat "$fit_file" | wc -c) 2> /dev/null)
 
 	nand_upgrade_prepare_ubi "" "" "$fit_length" "1" || return 1
 
 	local fit_ubidev="$(nand_find_ubi "$CI_UBIPART")"
 	local fit_ubivol="$(nand_find_volume $fit_ubidev "$CI_KERNPART")"
-	ubiupdatevol /dev/$fit_ubivol -s $fit_length $fit_file
+	${gz}cat "$fit_file" | ubiupdatevol /dev/$fit_ubivol -s "$fit_length" -
 }
 
 # Write images in the TAR file to MTD partitions and/or UBI volumes as required
 nand_upgrade_tar() {
 	local tar_file="$1"
+	local gz="$2"
 
 	# WARNING: This fails if tar contains more than one 'sysupgrade-*' directory.
-	local board_dir="$(tar tf "$tar_file" | grep -m 1 '^sysupgrade-.*/$')"
+	local board_dir="$(tar t${gz}f "$tar_file" | grep -m 1 '^sysupgrade-.*/$')"
 	board_dir="${board_dir%/}"
 
 	local kernel_mtd kernel_length
 	if [ "$CI_KERNPART" != "none" ]; then
 		kernel_mtd="$(find_mtd_index "$CI_KERNPART")"
-		kernel_length=$( (tar xf "$tar_file" "$board_dir/kernel" -O | wc -c) 2> /dev/null)
+		kernel_length=$( (tar x${gz}f "$tar_file" "$board_dir/kernel" -O | wc -c) 2> /dev/null)
 		[ "$kernel_length" = 0 ] && kernel_length=
 	fi
-	local rootfs_length=$( (tar xf "$tar_file" "$board_dir/root" -O | wc -c) 2> /dev/null)
+	local rootfs_length=$( (tar x${gz}f "$tar_file" "$board_dir/root" -O | wc -c) 2> /dev/null)
 	[ "$rootfs_length" = 0 ] && rootfs_length=
 	local rootfs_type
-	[ "$rootfs_length" ] && rootfs_type="$(identify_tar "$tar_file" "$board_dir/root")"
+	[ "$rootfs_length" ] && rootfs_type="$(identify_tar "$tar_file" "$board_dir/root" "$gz")"
 
 	local ubi_kernel_length
 	if [ "$kernel_length" ]; then
@@ -325,17 +339,17 @@ nand_upgrade_tar() {
 	local ubidev="$( nand_find_ubi "$CI_UBIPART" )"
 	if [ "$rootfs_length" ]; then
 		local root_ubivol="$( nand_find_volume $ubidev "$CI_ROOTPART" )"
-		tar xf "$tar_file" "$board_dir/root" -O | \
-			ubiupdatevol /dev/$root_ubivol -s $rootfs_length -
+		tar x${gz}f "$tar_file" "$board_dir/root" -O | \
+			ubiupdatevol /dev/$root_ubivol -s "$rootfs_length" -
 	fi
 	if [ "$kernel_length" ]; then
 		if [ "$kernel_mtd" ]; then
-			tar xf "$tar_file" "$board_dir/kernel" -O | \
+			tar x${gz}f "$tar_file" "$board_dir/kernel" -O | \
 				mtd write - "$CI_KERNPART"
 		else
 			local kern_ubivol="$( nand_find_volume $ubidev "$CI_KERNPART" )"
-			tar xf "$tar_file" "$board_dir/kernel" -O | \
-				ubiupdatevol /dev/$kern_ubivol -s $kernel_length -
+			tar x${gz}f "$tar_file" "$board_dir/kernel" -O | \
+				ubiupdatevol /dev/$kern_ubivol -s "$kernel_length" -
 		fi
 	fi
 
@@ -343,15 +357,20 @@ nand_upgrade_tar() {
 }
 
 nand_do_flash_file() {
-	local file_type=$(identify "$1")
+	local file="$1"
+
+	local gz="$(identify_if_gzip "$file")"
+	local file_type="$(identify "$file" "" "$gz")"
+
+	[ "$gz" = z ] && echo "detected compressed firmware file"
 
 	[ ! "$(find_mtd_index "$CI_UBIPART")" ] && CI_UBIPART=rootfs
 
 	case "$file_type" in
-		"fit")		nand_upgrade_fit "$1";;
-		"ubi")		nand_upgrade_ubinized "$1";;
-		"ubifs")	nand_upgrade_ubifs "$1";;
-		*)		nand_upgrade_tar "$1";;
+		"fit")		nand_upgrade_fit "$file" "$gz";;
+		"ubi")		nand_upgrade_ubinized "$file" "$gz";;
+		"ubifs")	nand_upgrade_ubifs "$file" "$gz";;
+		*)		nand_upgrade_tar "$file" "$gz";;
 	esac
 }
 
@@ -362,8 +381,10 @@ nand_do_restore_config() {
 
 # Recognize type of passed file and start the upgrade process
 nand_do_upgrade() {
+	local file="$1"
+
 	sync
-	if nand_do_flash_file "$1" && nand_do_restore_config && sync; then
+	if nand_do_flash_file "$file" && nand_do_restore_config && sync; then
 		echo "sysupgrade successful"
 		umount -a
 		reboot -f
@@ -390,14 +411,17 @@ nand_do_upgrade() {
 # $(2): file to be checked
 nand_do_platform_check() {
 	local board_name="$1"
-	local tar_file="$2"
-	local control_length=$( (tar xf $tar_file sysupgrade-$board_name/CONTROL -O | wc -c) 2> /dev/null)
-	local file_type="$(identify $2)"
+	local file="$2"
+
+	local gz="$(identify_if_gzip "$file")"
+	local file_type="$(identify "$file" "" "$gz")"
 
-	[ "$control_length" = 0 -a "$file_type" != "ubi" -a "$file_type" != "ubifs" -a "$file_type" != "fit" ] && {
-		echo "Invalid sysupgrade file."
+	local control_length=$( (tar x${gz}f "$file" "sysupgrade-$board_name/CONTROL" -O | wc -c) 2> /dev/null)
+
+	if [ "$file_type" != "fit" -a "$file_type" != "ubi" -a "$file_type" != "ubifs" -a "$control_length" = 0 ]; then
+		echo "invalid sysupgrade file"
 		return 1
-	}
+	fi
 
 	return 0
 }