AK3: add support for avb patching (#70)

- this supports custom kernel users to continue not having to fastboot reflash vbmeta with --disable-verity and --disable-verification, now that Magisk 24303+ no longer patches avb out of the fstab on-the-fly at boot time
- checks for an avb option in the fstab entry for the current partition
- if found, it checks if verity or verification is disabled on the top-level vbmeta, and if so, appends a hashtree and FEC data to the partition and updates the hashtree descriptor in the vbmeta partition referenced in the avb option

LICENSE

@@ -94,6 +94,50 @@ lptools_static: Apache License 2.0
     Source not required, however, respective source is provided:
     https://github.com/phhusson/vendor_lptools
 
+httools_static: MIT
+
+    Copyright (c) 2022 capntrips
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+
+    Source not required, however, respective source is provided:
+    https://github.com/capntrips/HashtreePatcher
+
+fec: Apache License 2.0
+
+    Copyright (c) 2013-2015, The Android Open Source Project
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+         http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+
+    Source not required, however, respective source is provided:
+    https://android.googlesource.com/platform/system/extras/+/refs/tags/android-12.1.0_r5/verity/fec/
+
 
 ## Optional Binary Licenses:
 

META-INF/com/google/android/updater-script

@@ -3,4 +3,4 @@
 # Dummy file; update-binary is a shell script (DO NOT CHANGE)
 #
 #
-# AK_BASE_VERSION=20220607
+# AK_BASE_VERSION=20220608

tools/ak3-core.sh

@@ -415,7 +415,7 @@ flash_boot() {
 
 # flash_generic <name>
 flash_generic() {
-  local file img imgblock isro path;
+  local avb avbblock file flags img imgblock isro path;
 
   cd $home;
   for file in $1 $1.img; do
@@ -438,6 +438,27 @@ flash_generic() {
       abort "$1 partition could not be found. Aborting...";
     fi;
     if [ "$path" == "/dev/block/mapper" ]; then
+      avb=$($bin/httools_static avb $1);
+      [ $? == 0 ] || abort "Failed to parse fstab entry for $1. Aborting...";
+      if [ "$avb" ]; then
+        flags=$($bin/httools_static disable-flags);
+        [ $? == 0 ] || abort "Failed to parse top-level vbmeta. Aborting...";
+        if [ "$flags" == "enabled" ]; then
+          [ "$1" == "vendor_dlkm" -a "$avb" == "vbmeta" ] || abort "Unable to patch $1 on $avb. Aborting ...";
+          ui_print " " "dm-verity detected! Patching vbmeta...";
+          for path in /dev/block/bootdevice/by-name /dev/block/mapper; do
+            for file in $avb $avb$slot; do
+              if [ -e $path/$file ]; then
+                avbblock=$path/$file;
+                break 2;
+              fi;
+            done;
+          done;
+          cd $bin;
+          $bin/httools_static patch $home/$img $avbblock || abort "Failed to patch $1 on $avb. Aborting...";
+          cd $home;
+        fi
+      fi
       $bin/lptools_static remove $1_ak3;
       $bin/lptools_static create $1_ak3 $(wc -c < $img) || abort "Creating $1_ak3 failed. Aborting...";
       $bin/lptools_static unmap $1_ak3 || abort "Unmapping $1_ak3 failed. Aborting...";