context: read configuration from and write logs and temp files to private app storage

The external app public storage directory is no longer reliably accessible on Android 11 and above.
This makes editing the configuration and accessing the log files impossible in some cases.

Let's move to the app private storage, to be made accessible to the user by some other mean.

This has the benefit of also protecting the private keys that need to be stored encrypted otherwise.
We also split the configuration and cache directory into specialised sub-directories.

GitHub: related to #103

1 files changed, 13 insertions, 11 deletions

diff --git a/app/src/main/java/org/pacien/tincapp/context/AppPaths.kt b/app/src/main/java/org/pacien/tincapp/context/AppPaths.kt
index bd8316a..9aa2037 100644
--- a/app/src/main/java/org/pacien/tincapp/context/AppPaths.kt
+++ b/app/src/main/java/org/pacien/tincapp/context/AppPaths.kt
@@ -18,7 +18,6 @@
 
 package org.pacien.tincapp.context
 
-import android.os.Environment
 import java.io.File
 import java.io.FileNotFoundException
 
@@ -28,6 +27,10 @@ import java.io.FileNotFoundException
  * @implNote Logs and PID files are stored in the cache directory for automatic collection.
  */
 object AppPaths {
+  private const val APP_LOG_DIR = "log"
+  private const val APP_TINC_RUNTIME_DIR = "run"
+  private const val APP_TINC_NETWORKS_DIR = "networks"
+
   private const val TINCD_BIN = "libtincd.so"
   private const val TINC_BIN = "libtinc.so"
 
@@ -46,25 +49,24 @@ object AppPaths {
 
   private val context by lazy { App.getContext() }
 
-  fun storageAvailable() =
-    Environment.getExternalStorageState().let { it == Environment.MEDIA_MOUNTED && it != Environment.MEDIA_MOUNTED_READ_ONLY }
-
-  fun internalCacheDir() = context.cacheDir!!
-  fun cacheDir() = context.externalCacheDir ?: internalCacheDir()
-  fun confDir() = context.getExternalFilesDir(null)!!
+  private fun cacheDir() = context.cacheDir!!
   private fun binDir() = File(context.applicationInfo.nativeLibraryDir)
+  fun runtimeDir() = withDir(File(cacheDir(), APP_TINC_RUNTIME_DIR))
+  fun logDir() = withDir(File(cacheDir(), APP_LOG_DIR))
+  fun confDir() = withDir(File(context.filesDir!!, APP_TINC_NETWORKS_DIR))
 
   fun confDir(netName: String) = File(confDir(), netName)
   fun hostsDir(netName: String) = File(confDir(netName), NET_HOSTS_DIR)
   fun netConfFile(netName: String) = File(confDir(netName), NET_CONF_FILE)
   fun tincConfFile(netName: String) = File(confDir(netName), NET_TINC_CONF_FILE)
   fun invitationFile(netName: String) = File(confDir(netName), NET_INVITATION_FILE)
-  fun logFile(netName: String) = File(cacheDir(), String.format(LOGFILE_FORMAT, netName))
-  fun pidFile(netName: String) = File(context.cacheDir, String.format(PIDFILE_FORMAT, netName))
-  fun appLogFile() = File(cacheDir(), APPLOG_FILE)
-  fun crashFlagFile() = File(internalCacheDir(), CRASHFLAG_FILE)
+  fun logFile(netName: String) = File(logDir(), String.format(LOGFILE_FORMAT, netName))
+  fun pidFile(netName: String) = File(runtimeDir(), String.format(PIDFILE_FORMAT, netName))
+  fun appLogFile() = File(logDir(), APPLOG_FILE)
+  fun crashFlagFile() = File(cacheDir(), CRASHFLAG_FILE)
 
   fun existing(f: File) = f.apply { if (!exists()) throw FileNotFoundException(f.absolutePath) }
+  fun withDir(f: File) = f.apply { if (!exists()) mkdirs() }
 
   fun defaultEd25519PrivateKeyFile(netName: String) = File(confDir(netName), NET_DEFAULT_ED25519_PRIVATE_KEY_FILE)
   fun defaultRsaPrivateKeyFile(netName: String) = File(confDir(netName), NET_DEFAULT_RSA_PRIVATE_KEY_FILE)