vendor: add custom backuptools and postinstall script for A/B OTAs
* A/B OTA devices wont run backuptools in recovery (because they don't
go in to recovery to do an OTA). In these cases let's use a modified
version to backup/restore from within android upon postinstall.
* Add backuptool_postinstall.sh which will be run prior to the normal
postinstall script in order to backup/restore via addon.d scripts.
* This needs to be done in such a manner because we need /postinstall
mounted rw instead of the ro with context= options which are used for
the normal postinstall (dexopt) script.
Change-Id: I51511870634dd1ec5388adafddb446f95cc5a950
diff --git a/prebuilt/common/bin/backuptool_ab.sh b/prebuilt/common/bin/backuptool_ab.sh
new file mode 100755
index 0000000..00f5da0
--- /dev/null
+++ b/prebuilt/common/bin/backuptool_ab.sh
@@ -0,0 +1,124 @@
+#!/system/bin/sh
+#
+# Backup and restore addon /system files
+#
+
+export S=/system
+export C=/postinstall/tmp/backupdir
+export V=8.1
+
+# Scripts in /system/addon.d expect to find backuptool.functions in /tmp
+mkdir -p /postinstall/tmp/
+cp -f /postinstall/system/bin/backuptool_ab.functions /postinstall/tmp/backuptool.functions
+
+# Preserve /system/addon.d in /tmp/addon.d
+preserve_addon_d() {
+ if [ -d /system/addon.d/ ]; then
+ mkdir -p /postinstall/tmp/addon.d/
+ cp -a /system/addon.d/* /postinstall/tmp/addon.d/
+ chmod 755 /postinstall/tmp/addon.d/*.sh
+ fi
+}
+
+# Restore /postinstall/system/addon.d from /postinstall/tmp/addon.d
+restore_addon_d() {
+ if [ -d /postinstall/tmp/addon.d/ ]; then
+ mkdir -p /postinstall/system/addon.d/
+ cp -a /postinstall/tmp/addon.d/* /postinstall/system/addon.d/
+ rm -rf /postinstall/tmp/addon.d/
+ fi
+}
+
+# Proceed only if /system is the expected major and minor version
+check_prereq() {
+# If there is no build.prop file the partition is probably empty.
+if [ ! -r /system/build.prop ]; then
+ return 0
+fi
+
+grep -q "^ro.omni.version=$V.*" /system/etc/prop.default /system/build.prop && return 1
+
+echo "Not backing up files from incompatible version: $V"
+return 0
+}
+
+check_blacklist() {
+ if [ -f /system/addon.d/blacklist -a -d /$1/addon.d/ ]; then
+ ## Discard any known bad backup scripts
+ cd /$1/addon.d/
+ for f in *sh; do
+ [ -f $f ] || continue
+ s=$(md5sum $f | cut -c-32)
+ grep -q $s /system/addon.d/blacklist && rm -f $f
+ done
+ fi
+}
+
+check_whitelist() {
+ found=0
+ if [ -f /system/addon.d/whitelist ];then
+ ## forcefully keep any version-independent stuff
+ cd /$1/addon.d/
+ for f in *sh; do
+ s=$(md5sum $f | cut -c-32)
+ grep -q $s /system/addon.d/whitelist
+ if [ $? -eq 0 ]; then
+ found=1
+ else
+ rm -f $f
+ fi
+ done
+ fi
+ return $found
+}
+
+# Execute /system/addon.d/*.sh scripts with $1 parameter
+run_stage() {
+if [ -d /postinstall/tmp/addon.d/ ]; then
+ for script in $(find /postinstall/tmp/addon.d/ -name '*.sh' |sort -n); do
+ # we have no /sbin/sh in android, only recovery
+ # use /system/bin/sh here instead
+ sed -i '0,/#!\/sbin\/sh/{s|#!/sbin/sh|#!/system/bin/sh|}' $script
+ # we can't count on /tmp existing on an A/B device, so utilize /postinstall/tmp
+ # as a pseudo-/tmp dir
+ sed -i 's|. /tmp/backuptool.functions|. /postinstall/tmp/backuptool.functions|g' $script
+ $script $1
+ done
+fi
+}
+
+case "$1" in
+ backup)
+ mkdir -p $C
+ if check_prereq; then
+ if check_whitelist postinstall/system; then
+ exit 127
+ fi
+ fi
+ check_blacklist postinstall/system
+ preserve_addon_d
+ run_stage pre-backup
+ run_stage backup
+ run_stage post-backup
+ ;;
+ restore)
+ if check_prereq; then
+ if check_whitelist postinstall/tmp; then
+ exit 127
+ fi
+ fi
+ check_blacklist postinstall/tmp
+ run_stage pre-restore
+ run_stage restore
+ run_stage post-restore
+ restore_addon_d
+ rm -rf $C
+ rm -rf /postinstall/tmp
+ sync
+ ;;
+ *)
+ echo "Usage: $0 {backup|restore}"
+ exit 1
+esac
+
+exit 0