Android: Use mode a+rwx for directories and a+rw for files in external storage path.

Issue love2d/love-android#269.

src/common/android.cpp

@@ -175,10 +175,24 @@ bool directoryExists(const char *path)
 
 bool mkdir(const char *path)
 {
-	int err = ::mkdir(path, 0770);
+	int err = ::mkdir(path, S_IRWXU | S_IRWXG | S_IRWXO | S_ISGID);
 	if (err == -1)
 	{
-		SDL_Log("Error: Could not create directory %s", path);
+		const char *error = strerror(errno);
+		SDL_Log("Error: Could not create directory '%s': %s", path, error);
+		return false;
+	}
+
+	return true;
+}
+
+bool chmod(const char *path, int mode)
+{
+	int err = ::chmod(path, mode);
+	if (err == -1)
+	{
+		const char *error = strerror(errno);
+		SDL_Log("Error: Could not change mode '%s': %s", path, error);
 		return false;
 	}
 
@@ -216,11 +230,11 @@ bool createStorageDirectories()
 	return true;
 }
 
-void fixupPermissionSingleFile(const std::string &savedir, const std::string &path)
+void fixupPermissionSingleFile(const std::string &savedir, const std::string &path, int mode)
 {
     std::string fixedSavedir = savedir.back() == '/' ? savedir : (savedir + "/");
     std::string target = fixedSavedir + path;
-    ::chmod(target.c_str(), 0660);
+    ::chmod(target.c_str(), mode);
 }
 
 void fixupExternalStoragePermission(const std::string &savedir, const std::string &path)
@@ -242,7 +256,7 @@ void fixupExternalStoragePermission(const std::string &savedir, const std::strin
 	}
 
 	std::string fixedSavedir = savedir.back() == '/' ? savedir : (savedir + "/");
-    ::chmod(savedir.c_str(), 0770);
+	chmod(savedir.c_str(), S_IRWXU | S_IRWXG | S_IRWXO | S_ISGID);
 
 	for (const std::string &dir: pathsToFix)
 	{
@@ -250,7 +264,7 @@ void fixupExternalStoragePermission(const std::string &savedir, const std::strin
 		if (!dir.empty() && strcmp(realPath, savedir.c_str()) == 0)
 		{
 			std::string target = fixedSavedir + dir;
-			::chmod(target.c_str(), 0770);
+			chmod(target.c_str(), S_IRWXU | S_IRWXG | S_IRWXO | S_ISGID);
 		}
 	}
 }

src/common/android.h

@@ -65,7 +65,7 @@ bool mkdir(const char *path);
 
 bool createStorageDirectories();
 
-void fixupPermissionSingleFile(const std::string &savedir, const std::string &path);
+void fixupPermissionSingleFile(const std::string &savedir, const std::string &path, int mode = 0666);
 
 void fixupExternalStoragePermission(const std::string &savedir, const std::string &path);
 

src/modules/filesystem/Filesystem.cpp

@@ -133,7 +133,21 @@ static bool createDirectoryRaw(const std::string &path)
 	std::wstring wpath = to_widestr(path);
 	return CreateDirectoryW(wpath.c_str(), nullptr) != 0;
 #else
-	return mkdir(path.c_str(), S_IRWXU) == 0;
+	int mode = S_IRWXU;
+
+#ifdef LOVE_ANDROID
+	// Need to create save directory with ugo+rwx and setgid bit if
+	// t.externalstorage is set and it's for save directory.
+	auto fs = Module::getInstance<Filesystem>(Module::M_FILESYSTEM);
+	if (fs != nullptr && fs->isAndroidSaveExternal())
+	{
+		const std::string &savedir = fs->getFullCommonPath(Filesystem::COMMONPATH_APP_SAVEDIR);
+		if (path.rfind(savedir, 0) == 0)
+			mode |= S_IRWXG | S_IRWXO | S_ISGID;
+	}
+#endif
+
+	return mkdir(path.c_str(), mode) == 0;
 #endif
 }
 

src/modules/filesystem/physfs/File.cpp

@@ -57,7 +57,7 @@ File::File(const std::string &filename, Mode mode)
 
 #ifdef LOVE_ANDROID
 	// In Android with t.externalstorage = true, make sure the file opened or
-	// created in the save directory has permissions of ug+rw (0660) so that
+	// created in the save directory has permissions of ugo+rw (0666) so that
 	// it's accessible through MTP.
 	auto fs = Module::getInstance<love::filesystem::Filesystem>(Module::M_FILESYSTEM);
 	if (fs != nullptr && fs->isAndroidSaveExternal())

src/modules/filesystem/physfs/Filesystem.cpp

@@ -803,7 +803,7 @@ bool Filesystem::createDirectory(const char *dir)
 
 #ifdef LOVE_ANDROID
 	// In Android with t.externalstorage = true, make sure the directory
-    // created in the save directory has permissions of ug+rwx (0770) so that
+    // created in the save directory has permissions of ugo+rwx (0777) so that
     // it's accessible through MTP.
 	if (isAndroidSaveExternal())
 		love::android::fixupExternalStoragePermission(