add: APatch support (#4)

This commit adds support for APatch.

loader/src/common/daemon.cpp

@@ -153,7 +153,9 @@ namespace zygiskd {
 
         int flags = socket_utils::read_u32(fd);
 
-        if (flags & (1 << 29)) {
+        if (flags & (1 << 27)) {
+          info->root_impl = ZYGOTE_ROOT_IMPL_APATCH;
+        } else if (flags & (1 << 29)) {
           info->root_impl = ZYGOTE_ROOT_IMPL_KERNELSU;
         } else if (flags & (1 << 30)) {
           info->root_impl = ZYGOTE_ROOT_IMPL_MAGISK;

loader/src/include/daemon.h

@@ -44,6 +44,7 @@ private:
 
 enum zygote_root_impl {
   ZYGOTE_ROOT_IMPL_NONE,
+  ZYGOTE_ROOT_IMPL_APATCH,
   ZYGOTE_ROOT_IMPL_KERNELSU,
   ZYGOTE_ROOT_IMPL_MAGISK
 };

loader/src/injector/hook.cpp

@@ -145,6 +145,8 @@ DCL_HOOK_FUNC(int, unshare, int flags) {
         if (g_ctx->flags[DO_REVERT_UNMOUNT]) {
             if (g_ctx->info_flags & PROCESS_ROOT_IS_KSU) {
                 revert_unmount_ksu();
+            } else if (g_ctx->info_flags & PROCESS_ROOT_IS_APATCH){
+                revert_unmount_apatch();
             } else if (g_ctx->info_flags & PROCESS_ROOT_IS_MAGISK) {
                 revert_unmount_magisk();
             }

loader/src/injector/module.hpp

@@ -113,6 +113,7 @@ namespace {
         PROCESS_ON_DENYLIST = zygisk::StateFlag::PROCESS_ON_DENYLIST,
 
         PROCESS_IS_MANAGER = (1u << 28),
+        PROCESS_ROOT_IS_APATCH = (1u << 27),
         PROCESS_ROOT_IS_KSU = (1u << 29),
         PROCESS_ROOT_IS_MAGISK = (1u << 30),
         PROCESS_IS_SYS_UI = (1u << 31),

loader/src/injector/unmount.cpp

@@ -11,6 +11,7 @@ using namespace std::string_view_literals;
 namespace {
     constexpr auto MODULE_DIR = "/data/adb/modules";
     constexpr auto KSU_OVERLAY_SOURCE = "KSU";
+    constexpr auto AP_OVERLAY_SOURCE = "APatch";
     const std::vector<std::string> KSU_PARTITIONS{"/system", "/vendor", "/product", "/system_ext", "/odm", "/oem"};
 
     void lazy_unmount(const char* mountpoint) {
@@ -84,3 +85,43 @@ void revert_unmount_magisk() {
         lazy_unmount(s.data());
     }
 }
+
+void revert_unmount_apatch() {
+    std::string ksu_loop;
+    std::vector<std::string> targets;
+
+    // Unmount ksu module dir last
+    targets.emplace_back(MODULE_DIR);
+
+    for (auto& info: parse_mount_info("self")) {
+        if (info.target == MODULE_DIR) {
+            ksu_loop = info.source;
+            continue;
+        }
+        // Unmount everything mounted to /data/adb
+        if (info.target.starts_with("/data/adb")) {
+            targets.emplace_back(info.target);
+        }
+        // Unmount ksu overlays
+        if (info.type == "overlay"
+            && info.source == AP_OVERLAY_SOURCE
+            && std::find(KSU_PARTITIONS.begin(), KSU_PARTITIONS.end(), info.target) != KSU_PARTITIONS.end()) {
+            targets.emplace_back(info.target);
+        }
+        // Unmount temp dir
+        if (info.type == "tmpfs" && info.source == AP_OVERLAY_SOURCE) {
+            targets.emplace_back(info.target);
+        }
+    }
+    for (auto& info: parse_mount_info("self")) {
+        // Unmount everything from ksu loop except ksu module dir
+        if (info.source == ksu_loop && info.target != MODULE_DIR) {
+            targets.emplace_back(info.target);
+        }
+    }
+
+    // Do unmount
+    for (auto& s: reversed(targets)) {
+        lazy_unmount(s.data());
+    }
+}

loader/src/injector/zygisk.hpp

@@ -12,3 +12,4 @@ void revert_unmount_ksu();
 
 void revert_unmount_magisk();
 
+void revert_unmount_apatch();

loader/src/ptracer/main.cpp

@@ -108,6 +108,11 @@ int main(int argc, char **argv) {
 
         break;
       }
+      case ZYGOTE_ROOT_IMPL_APATCH: {
+        printf("Root implementation: APatch\n");
+        
+        break;
+      }
       case ZYGOTE_ROOT_IMPL_KERNELSU: {
         printf("Root implementation: KernelSU\n");