Merge Magisk install zip into Magisk Manager

Distribute Magisk directly with Magisk Manager APK. The APK will
contain all required binaries and scripts for installation and
uninstallation. App versions will now align with Magisk releases.

Extra effort is spent to make the APK itself also a flashable zip that
can be used in custom recoveries, so those still prefer to install
Magisk with recoveries will not be affected with this change.

As a bonus, this makes the whole installation and uninstallation
process 100% offline. The existing Magisk Manager was not really
functional without an Internet connection, as the installation process
was highly tied to zips hosted on the server.

An additional bonus: since all binaries are now shipped as "native
libraries" of the APK, we can finally bump the target SDK version
higher than 28. The target SDK version was stuck at 28 for a long time
because newer SELinux restricts running executables from internal
storage. More details can be found here: https://github.com/termux/termux-app/issues/1072
The target SDK bump will be addressed in a future commit.

Co-authored with @vvb2060

scripts/util_functions.sh

@@ -1,8 +1,5 @@
 ############################################
-#
 # Magisk General Utility Functions
-# by topjohnwu
-#
 ############################################
 
 #MAGISK_VERSION_STUB
@@ -33,7 +30,7 @@ grep_prop() {
   shift
   local FILES=$@
   [ -z "$FILES" ] && FILES='/system/build.prop'
-  cat $FILES | dos2unix | sed -n "$REGEX" 2>/dev/null | head -n 1
+  cat $FILES 2>/dev/null | dos2unix | sed -n "$REGEX" | head -n 1
 }
 
 getvar() {
@@ -42,11 +39,11 @@ getvar() {
   local PROPPATH='/data/.magisk /cache/.magisk'
   [ -n $MAGISKTMP ] && PROPPATH="$MAGISKTMP/config $PROPPATH"
   VALUE=$(grep_prop $VARNAME $PROPPATH)
-  [ ! -z $VALUE ] && eval $VARNAME=\$VALUE
+  [ -n $VALUE ] && eval $VARNAME=\$VALUE
 }
 
 is_mounted() {
-  grep -q " `readlink -f $1` " /proc/mounts 2>/dev/null
+  grep -q " $(readlink -f $1) " /proc/mounts 2>/dev/null
   return $?
 }
 
@@ -96,6 +93,7 @@ setup_flashable() {
       fi
     done
   fi
+  recovery_actions
 }
 
 ensure_bb() {
@@ -309,51 +307,57 @@ mount_apex() {
   $BOOTMODE || [ ! -d /system/apex ] && return
   local APEX DEST
   setup_mntpoint /apex
+  mount -t tmpfs tmpfs /apex -o mode=755
+  local PATTERN='s/.*"name":[^"]*"\([^"]*\).*/\1/p'
   for APEX in /system/apex/*; do
-    DEST=/apex/$(basename $APEX .apex)
-    [ "$DEST" == /apex/com.android.runtime.release ] && DEST=/apex/com.android.runtime
-    mkdir -p $DEST 2>/dev/null
     if [ -f $APEX ]; then
       # APEX APKs, extract and loop mount
       unzip -qo $APEX apex_payload.img -d /apex
-      loop_setup apex_payload.img
+      DEST=/apex/$(unzip -qp $APEX apex_manifest.pb | strings | head -n 1)
+      [ -z $DEST ] && DEST=/apex/$(unzip -qp $APEX apex_manifest.json | sed -n $PATTERN)
+      [ -z $DEST ] && continue
+      mkdir -p $DEST
+      loop_setup /apex/apex_payload.img
       if [ ! -z $LOOPDEV ]; then
         ui_print "- Mounting $DEST"
         mount -t ext4 -o ro,noatime $LOOPDEV $DEST
       fi
-      rm -f apex_payload.img
+      rm -f /apex/apex_payload.img
     elif [ -d $APEX ]; then
       # APEX folders, bind mount directory
+      if [ -f $APEX/apex_manifest.json ]; then
+        DEST=/apex/$(sed -n $PATTERN $APEX/apex_manifest.json)
+      elif [ -f $APEX/apex_manifest.pb ]; then
+        DEST=/apex/$(strings apex_manifest.pb | head -n 1)
+      else
+        continue
+      fi
+      mkdir -p $DEST
       ui_print "- Mounting $DEST"
       mount -o bind $APEX $DEST
     fi
   done
   export ANDROID_RUNTIME_ROOT=/apex/com.android.runtime
   export ANDROID_TZDATA_ROOT=/apex/com.android.tzdata
-  local APEXRJPATH=/apex/com.android.runtime/javalib
-  local SYSFRAME=/system/framework
-  export BOOTCLASSPATH=\
-$APEXRJPATH/core-oj.jar:$APEXRJPATH/core-libart.jar:$APEXRJPATH/okhttp.jar:\
-$APEXRJPATH/bouncycastle.jar:$APEXRJPATH/apache-xml.jar:$SYSFRAME/framework.jar:\
-$SYSFRAME/ext.jar:$SYSFRAME/telephony-common.jar:$SYSFRAME/voip-common.jar:\
-$SYSFRAME/ims-common.jar:$SYSFRAME/android.test.base.jar:$SYSFRAME/telephony-ext.jar:\
-/apex/com.android.conscrypt/javalib/conscrypt.jar:\
-/apex/com.android.media/javalib/updatable-media.jar
+  export ANDROID_ART_ROOT=/apex/com.android.art
+  export ANDROID_I18N_ROOT=/apex/com.android.i18n
+  local APEXJARS=$(find /apex -name '*.jar' | sort | tr '\n' ':')
+  local FWK=/system/framework
+  export BOOTCLASSPATH=${APEXJARS}\
+$FWK/framework.jar:$FWK/ext.jar:$FWK/telephony-common.jar:\
+$FWK/voip-common.jar:$FWK/ims-common.jar:$FWK/telephony-ext.jar
 }
 
 umount_apex() {
   [ -d /apex ] || return
-  local DEST SRC
-  for DEST in /apex/*; do
-    [ "$DEST" = '/apex/*' ] && break
-    SRC=$(grep $DEST /proc/mounts | awk '{ print $1 }')
-    umount -l $DEST
-    # Detach loop device just in case
-    losetup -d $SRC 2>/dev/null
+  umount -l /apex
+  for loop in /dev/block/loop*; do
+    losetup -d $loop 2>/dev/null
   done
-  rm -rf /apex
   unset ANDROID_RUNTIME_ROOT
   unset ANDROID_TZDATA_ROOT
+  unset ANDROID_ART_ROOT
+  unset ANDROID_I18N_ROOT
   unset BOOTCLASSPATH
 }
 
@@ -389,7 +393,7 @@ find_boot_image() {
   BOOTIMAGE=
   if $RECOVERYMODE; then
     BOOTIMAGE=`find_block recovery_ramdisk$SLOT recovery$SLOT sos`
-  elif [ ! -z $SLOT ]; then
+  elif [ -n $SLOT ]; then
     BOOTIMAGE=`find_block ramdisk$SLOT recovery_ramdisk$SLOT boot$SLOT`
   else
     BOOTIMAGE=`find_block ramdisk recovery_ramdisk kern-a android_boot kernel bootimg boot lnx boot_a`
@@ -402,7 +406,7 @@ find_boot_image() {
 
 flash_image() {
   case "$1" in
-    *.gz) CMD1="$MAGISKBIN/magiskboot decompress '$1' - 2>/dev/null";;
+    *.gz) CMD1="gzip -d < '$1' 2>/dev/null";;
     *)    CMD1="cat '$1'";;
   esac
   if $BOOTSIGNED; then