Android: Ask for the local network permission before starting file upload

Part of #21585

Android 17 apps need ACCESS_LOCAL_NETWORK to serve other devices on the LAN.
The upload screen now asks for it when it opens, starts the web server once
it's granted, and shows a warning and a retry button if it's denied.

The permission only exists from API 37, so check for that rather than 35.
On Android 15 and 16 it reads as denied, which left Remote ISO's connect tab
stuck behind a permission request that could never succeed.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

UI/UploadScreen.cpp

@@ -5,6 +5,8 @@
 #include "Common/StringUtils.h"
 #include "Common/Data/Text/Parsers.h"
 #include "Common/Data/Text/I18n.h"
+#include "Common/UI/Notice.h"
+#include "Common/System/System.h"
 #include "Core/WebServer.h"
 #include "Core/Util/PathUtil.h"
 #include "UI/UploadScreen.h"
@@ -19,12 +21,27 @@ UploadScreen::UploadScreen(const Path &targetFolder) : UISimpleBaseDialogScreen(
 			localIPs_.push_back(ip);
 		}
 	}
-	WebServerSetUploadPath(targetFolder);
-	StartWebServer(WebServerFlags::FILE_UPLOAD);
+	// On Android 17+, serving to other devices on the local network needs a runtime permission.
+	prevPermission_ = System_GetPermissionStatus(SYSTEM_PERMISSION_LOCAL_NETWORK);
+	if (prevPermission_ != PERMISSION_STATUS_GRANTED) {
+		System_AskForPermission(SYSTEM_PERMISSION_LOCAL_NETWORK);
+	}
+	StartServerIfPermitted();
 }
 
 UploadScreen::~UploadScreen() {
-	StopWebServer(WebServerFlags::FILE_UPLOAD);
+	if (started_) {
+		StopWebServer(WebServerFlags::FILE_UPLOAD);
+	}
+}
+
+void UploadScreen::StartServerIfPermitted() {
+	if (started_ || System_GetPermissionStatus(SYSTEM_PERMISSION_LOCAL_NETWORK) != PERMISSION_STATUS_GRANTED) {
+		return;
+	}
+	WebServerSetUploadPath(targetFolder_);
+	StartWebServer(WebServerFlags::FILE_UPLOAD);
+	started_ = true;
 }
 
 void UploadScreen::CreateDialogViews(UI::ViewGroup *root) {
@@ -37,7 +54,12 @@ void UploadScreen::CreateDialogViews(UI::ViewGroup *root) {
 	container->Add(new TextWithImage(ImageID("I_FOLDER_UPLOAD"), GetFriendlyPath(targetFolder_)));
 	container->Add(new Spacer(20.0f));
 
-	if (prevRunning_) {
+	if (prevPermission_ == PERMISSION_STATUS_DENIED) {
+		container->Add(new NoticeView(NoticeLevel::WARN, n->T("Local network permission is needed to receive files"), ""))->SetWrapText(true);
+		container->Add(new Choice(n->T("Ask for network permission")))->OnClick.Add([](UI::EventParams &e) {
+			System_AskForPermission(SYSTEM_PERMISSION_LOCAL_NETWORK);
+		});
+	} else if (prevRunning_) {
 		container->Add(new TextWithImage(ImageID("I_WIFI"), n->T("With a web browser on the same network, go to:")));
 		for (const auto &ip : localIPs_) {
 			std::string url = StringFromFormat("%s:%d/upload", ip.c_str(), WebServerPort());
@@ -74,6 +96,13 @@ std::string_view UploadScreen::GetTitle() const {
 
 void UploadScreen::update() {
 	UISimpleBaseDialogScreen::update();
+	PermissionStatus permission = System_GetPermissionStatus(SYSTEM_PERMISSION_LOCAL_NETWORK);
+	if (permission != prevPermission_) {
+		prevPermission_ = permission;
+		StartServerIfPermitted();
+		RecreateViews();
+	}
+
 	bool running = WebServerRunning(WebServerFlags::FILE_UPLOAD);
 	if (prevRunning_ != running) {
 		prevRunning_ = running;

UI/UploadScreen.h

@@ -28,6 +28,7 @@
 #include "UI/BaseScreens.h"
 #include "UI/SimpleDialogScreen.h"
 #include "Common/TimeUtil.h"
+#include "Common/System/System.h"
 
 // Upload screen: Shows the user an ip address to go to in a web browser on the same network,
 // in order to upload game files to the current directory.
@@ -46,6 +47,9 @@ protected:
 
 private:
 	void RecreateStatus();
+	void StartServerIfPermitted();
+	bool started_ = false;
+	PermissionStatus prevPermission_ = PERMISSION_STATUS_UNKNOWN;
 	bool prevRunning_ = false;
 	std::vector<std::string> localIPs_;
 	Path targetFolder_;

android/src/org/ppsspp/ppsspp/PpssppActivity.java

@@ -249,7 +249,8 @@ public class PpssppActivity extends AppCompatActivity implements SensorEventList
 				NativeApp.sendMessageFromJava("permission_denied", "storage");
 			}
 
-			if (Build.VERSION.SDK_INT >= 35) {
+			// ACCESS_LOCAL_NETWORK exists from Android 17 (API 37). Earlier versions report it as denied.
+			if (Build.VERSION.SDK_INT >= 37) {
 				if (this.checkSelfPermission("android.permission.ACCESS_LOCAL_NETWORK") == PackageManager.PERMISSION_GRANTED) {
 					NativeApp.sendMessageFromJava("permission_granted", "local_network");
 				} else {
@@ -1828,7 +1829,7 @@ public class PpssppActivity extends AppCompatActivity implements SensorEventList
 			}
 			return true;
 		} else if (command.equals("ask_permission") && params.equals("local_network")) {
-			if (Build.VERSION.SDK_INT >= 35) {
+			if (Build.VERSION.SDK_INT >= 37) {
 				if (askForPermissions(permissionsForLocalNetwork, REQUEST_CODE_LOCAL_NETWORK_PERMISSION)) {
 					NativeApp.sendMessageFromJava("permission_pending", "local_network");
 				} else {

assets/lang/en_US.ini

@@ -985,6 +985,7 @@ Ad hoc server address = Ad hoc server address
 AdhocServer Failed to Bind Port = Ad hoc server failed to bind port
 Allow speed control while connected (not recommended) = Allow speed control while connected (not recommended)
 AM: Data from Unknown Port = AM: Data from Unknown Port
+Ask for network permission = Ask for network permission
 Auto = Auto
 Autoconfigure = Autoconfigure
 ChangeMacSaveConfirm = Generate a new MAC address?
@@ -1020,6 +1021,7 @@ Infrastructure = Infrastructure
 Infrastructure server provided by: = Infrastructure server provided by:
 Invalid IP or hostname = Invalid IP or hostname
 Local network addresses = Local network addresses
+Local network permission is needed to receive files = Local network permission is needed to receive files
 MAC address = MAC address
 Minimum Timeout = Minimum timeout (override in ms, 0 = default)
 Misc = Miscellaneous (default = PSP compatibility)