Remove dependency on librootjava

mobile/build.gradle.kts

@@ -93,7 +93,6 @@ dependencies {
     implementation("com.jakewharton.timber:timber:4.7.1")
     implementation("com.linkedin.dexmaker:dexmaker:2.28.0")
     implementation("com.takisoft.preferencex:preferencex-simplemenu:1.1.0")
-    implementation("eu.chainfire:librootjava:1.3.0")
     implementation("org.jetbrains.kotlinx:kotlinx-collections-immutable:0.3.2")
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.8")
     testImplementation("junit:junit:4.13")

mobile/src/main/java/be/mygod/librootkotlinx/AppProcess.kt

@@ -0,0 +1,72 @@
+package be.mygod.librootkotlinx
+
+import android.os.Build
+import android.os.Debug
+import android.os.Process
+import androidx.annotation.RequiresApi
+import java.io.File
+
+object AppProcess {
+    /**
+     * Based on: https://android.googlesource.com/platform/bionic/+/aff9a34/linker/linker.cpp#3397
+     */
+    @get:RequiresApi(29)
+    val genericLdConfigFilePath: String get() {
+        "/system/etc/ld.config.${Build.VERSION.SDK_INT}.txt".let { if (File(it).isFile) return it }
+        if (Build.VERSION.SDK_INT >= 30) "/linkerconfig/ld.config.txt".let {
+            check(File(it).isFile) { "failed to find generated linker configuration from \"$it\"" }
+            return it
+        }
+        val prop = Class.forName("android.os.SystemProperties")
+        if (prop.getDeclaredMethod("getBoolean", String::class.java, Boolean::class.java).invoke(null,
+                        "ro.vndk.lite", false) as Boolean) return "/system/etc/ld.config.vndk_lite.txt"
+        when (val version = prop.getDeclaredMethod("get", String::class.java, String::class.java).invoke(null,
+                "ro.vndk.version", "") as String) {
+            "", "current" -> { }
+            else -> "/system/etc/ld.config.$version.txt".let { if (File(it).isFile) return it }
+        }
+        return "/system/etc/ld.config.txt"
+    }
+
+    val myExe get() = "/proc/${Process.myPid()}/exe"
+
+    /**
+     * To workaround Samsung's stupid kernel patch that prevents exec, we need to relocate exe outside of /data.
+     * See also: https://github.com/Chainfire/librootjava/issues/19
+     *
+     * @return The script to be executed to perform relocation and the relocated binary path.
+     */
+    fun relocateScript(token: String): Pair<StringBuilder, String> {
+        val script = StringBuilder()
+        val (baseDir, relocated) = if (Build.VERSION.SDK_INT < 29) "/dev" to "/dev/app_process_$token" else {
+            val apexPath = "/apex/$token"
+            script.appendln("[ -d $apexPath ] || " +
+                    "mkdir $apexPath && " +
+                    // we need to mount a new tmpfs to override noexec flag
+                    "mount -t tmpfs -o size=1M tmpfs $apexPath || exit 1")
+            // unfortunately native ld.config.txt only recognizes /data,/system,/system_ext as system directories;
+            // to link correctly, we need to add our path to the linker config too
+            val ldConfig = "$apexPath/etc/ld.config.txt"
+            script.appendln("[ -f $ldConfig ] || " +
+                    "mkdir -p $apexPath/etc && " +
+                    "echo dir.system = $apexPath >$ldConfig && " +
+                    "cat $genericLdConfigFilePath >>$ldConfig || exit 1")
+            "$apexPath/bin" to "$apexPath/bin/app_process"
+        }
+        script.appendln("[ -f $relocated ] || " +
+                "mkdir -p $baseDir && " +
+                "cp $myExe $relocated && " +
+                "chmod 700 $relocated || exit 1")
+        return script to relocated
+    }
+
+    fun launchString(packageCodePath: String, clazz: String, appProcess: String, niceName: String?): String {
+        val debugParams = if (Debug.isDebuggerConnected()) when (Build.VERSION.SDK_INT) {
+            in 29..Int.MAX_VALUE -> "-XjdwpProvider:adbconnection"
+            28 -> "-XjdwpProvider:adbconnection -XjdwpOptions:suspend=n,server=y -Xcompiler-option --debuggable"
+            else -> "-Xrunjdwp:transport=dt_android_adb,suspend=n,server=y -Xcompiler-option --debuggable"
+        } else ""
+        val extraParams = if (niceName != null) " --nice-name=$niceName" else ""
+        return "CLASSPATH=$packageCodePath exec $appProcess $debugParams /system/bin$extraParams $clazz"
+    }
+}

mobile/src/main/java/be/mygod/librootkotlinx/RootServer.kt

@@ -1,7 +1,6 @@
 package be.mygod.librootkotlinx
 
 import android.content.Context
-import android.os.Build
 import android.os.Looper
 import android.os.Parcelable
 import android.os.RemoteException
@@ -11,9 +10,6 @@ import android.util.Log
 import androidx.collection.LongSparseArray
 import androidx.collection.set
 import androidx.collection.valueIterator
-import eu.chainfire.librootjava.AppProcess
-import eu.chainfire.librootjava.Logger
-import eu.chainfire.librootjava.RootJava
 import kotlinx.coroutines.*
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.channels.SendChannel
@@ -161,35 +157,10 @@ class RootServer @JvmOverloads constructor(private val warnLogger: (String) -> U
         val uuid = context.packageName + '@' + if (persistence.canRead()) persistence.readText() else {
             UUID.randomUUID().toString().also { persistence.writeText(it) }
         }
-        // to workaround Samsung's stupid kernel patch, we need to relocate outside of /data: https://github.com/Chainfire/librootjava/issues/19
-        val (baseDir, relocated) = if (Build.VERSION.SDK_INT < 29) "/dev" to "/dev/app_process_$uuid" else {
-            val apexPath = "/apex/$uuid"
-            writer.writeBytes("[ -d $apexPath ] || " +
-                    "mkdir $apexPath && " +
-                    // we need to mount a new tmpfs to override noexec flag
-                    "mount -t tmpfs -o size=1M tmpfs $apexPath || exit 1\n")
-            // unfortunately native ld.config.txt only recognizes /data,/system,/system_ext as system directories;
-            // to link correctly, we need to add our path to the linker config too
-            val ldConfig = "$apexPath/etc/ld.config.txt"
-            writer.writeBytes("[ -f $ldConfig ] || " +
-                    "mkdir -p $apexPath/etc && " +
-                    "echo dir.system = $apexPath >$ldConfig && " +
-                    "cat $genericLdConfigFilePath >>$ldConfig || exit 1\n")
-            "$apexPath/bin" to "$apexPath/bin/app_process"
-        }
-        writer.writeBytes("[ -f $relocated ] || " +
-                "mkdir -p $baseDir && " +
-                "cp /proc/${android.os.Process.myPid()}/exe $relocated && " +
-                "chmod 700 $relocated || exit 1\n")
-        writer.writeBytes(RootJava.getLaunchString(
-                context.packageCodePath + " exec",  // hack: plugging in exec
-                RootServer::class.java.name, relocated,
-                AppProcess.guessIfAppProcessIs64Bits(File("/proc/self/exe").canonicalPath),
-                arrayOf("$token2\n"), niceName).let { result ->
-            if (Build.VERSION.SDK_INT < 24) result
-            // undo the patch on newer APIs to let linker do the work
-            else result.replaceFirst(" LD_LIBRARY_PATH=", " __SUPPRESSED_LD_LIBRARY_PATH=")
-        })
+        val (script, relocated) = AppProcess.relocateScript(uuid)
+        script.appendln(AppProcess.launchString(context.packageCodePath, RootServer::class.java.name, relocated,
+                niceName) + " $token2")
+        writer.writeBytes(script.toString())
         writer.flush()
         reader.lookForToken(token2) // wait for ready signal
         output = writer
@@ -365,10 +336,6 @@ class RootServer @JvmOverloads constructor(private val warnLogger: (String) -> U
          */
         @JvmStatic
         var isDebugEnabled = false
-            set(value) {
-                field = value
-                Logger.setDebugLogging(value)
-            }
 
         private const val TAG = "RootServer"
         private const val SUCCESS = 0
@@ -435,7 +402,6 @@ class RootServer @JvmOverloads constructor(private val warnLogger: (String) -> U
 
         private fun rootMain(args: Array<String>) {
             require(args.isNotEmpty())
-            if (Build.VERSION.SDK_INT < 24) RootJava.restoreOriginalLdLibraryPath()
             val mainInitialized = CountDownLatch(1)
             val main = Thread({
                 @Suppress("DEPRECATION")

mobile/src/main/java/be/mygod/librootkotlinx/Utils.kt

@@ -4,37 +4,13 @@ package be.mygod.librootkotlinx
 
 import android.annotation.SuppressLint
 import android.content.Context
-import android.os.Build
 import android.os.Parcel
 import android.os.Parcelable
 import android.util.*
-import androidx.annotation.RequiresApi
 import kotlinx.android.parcel.Parcelize
-import java.io.File
 
 class NoShellException(cause: Throwable) : Exception("Root missing", cause)
 
-/**
- * Based on: https://android.googlesource.com/platform/bionic/+/aff9a34/linker/linker.cpp#3397
- */
-@get:RequiresApi(29)
-val genericLdConfigFilePath: String get() {
-    "/system/etc/ld.config.${Build.VERSION.SDK_INT}.txt".let { if (File(it).isFile) return it }
-    if (Build.VERSION.SDK_INT >= 30) "/linkerconfig/ld.config.txt".let {
-        check(File(it).isFile) { "failed to find generated linker configuration from \"$it\"" }
-        return it
-    }
-    val prop = Class.forName("android.os.SystemProperties")
-    if (prop.getDeclaredMethod("getBoolean", String::class.java, Boolean::class.java).invoke(null,
-                    "ro.vndk.lite", false) as Boolean) return "/system/etc/ld.config.vndk_lite.txt"
-    when (val version = prop.getDeclaredMethod("get", String::class.java, String::class.java).invoke(null,
-            "ro.vndk.version", "") as String) {
-        "", "current" -> { }
-        else -> "/system/etc/ld.config.$version.txt".let { if (File(it).isFile) return it }
-    }
-    return "/system/etc/ld.config.txt"
-}
-
 val systemContext by lazy {
     val classActivityThread = Class.forName("android.app.ActivityThread")
     val activityThread = classActivityThread.getMethod("systemMain").invoke(null)