From bb303c1e0f37463bbff6564b019b9be89b38753d Mon Sep 17 00:00:00 2001
From: Yukita Mayako <catgirl@goddess.moe>
Date: Sat, 5 Nov 2022 19:12:09 -0400
Subject: [PATCH] Allow skipping UPnP discovery by using cached IGD description
 URL

This is much faster than running a full discover,
but only works if the user's network hasn't changed.
---
 modules/upnp/doc_classes/UPNP.xml |  8 ++++++++
 modules/upnp/upnp.cpp             | 34 +++++++++++++++++++++++++++++++
 modules/upnp/upnp.h               |  1 +
 3 files changed, 43 insertions(+)

diff --git a/modules/upnp/doc_classes/UPNP.xml b/modules/upnp/doc_classes/UPNP.xml
index 92e25efbe04..b0ee8194d44 100644
--- a/modules/upnp/doc_classes/UPNP.xml
+++ b/modules/upnp/doc_classes/UPNP.xml
@@ -66,6 +66,14 @@
 				Adds the given [UPNPDevice] to the list of discovered devices.
 			</description>
 		</method>
+		<method name="add_device_from_url">
+			<return type="int" enum="UPNP.UPNPResult" />
+			<param index="0" name="desc_url" type="String" />
+			<description>
+				Discovers a [UPNPDevice] directly from the provided device description URL [code]desc_url[/code], allowing the much slower call to [method discover] to be skipped.
+				Returns one of the [enum UPNPResult] code constants ([constant UPNP_RESULT_SUCCESS] on success).
+			</description>
+		</method>
 		<method name="add_port_mapping" qualifiers="const">
 			<return type="int" />
 			<param index="0" name="port" type="int" />
diff --git a/modules/upnp/upnp.cpp b/modules/upnp/upnp.cpp
index 82fe39e0034..2ff9abb53fe 100644
--- a/modules/upnp/upnp.cpp
+++ b/modules/upnp/upnp.cpp
@@ -90,6 +90,39 @@ int UPNP::discover(int timeout, int ttl, const String &device_filter) {
 	return UPNP_RESULT_SUCCESS;
 }
 
+UPNP::UPNPResult UPNP::add_device_from_url(const String &desc_url) {
+	ERR_FAIL_COND_V_MSG(desc_url.is_empty(), UPNP_RESULT_INVALID_PARAM, "The description url must not be empty.");
+
+	Ref<UPNPDevice> dev;
+	struct UPNPUrls urls;
+	struct IGDdatas data;
+	char addr[16];
+
+	int i = UPNP_GetIGDFromUrl(desc_url.utf8().get_data(), &urls, &data, (char *)&addr, 16);
+	if (i != 1) {
+		FreeUPNPUrls(&urls);
+		return UPNP_RESULT_ACTION_FAILED;
+	}
+
+	if (urls.controlURL[0] == '\0') {
+		FreeUPNPUrls(&urls);
+		return UPNP_RESULT_INVALID_RESPONSE;
+	}
+
+	dev.instantiate();
+	dev->set_description_url(desc_url);
+	dev->set_service_type("urn:schemas-upnp-org:device:InternetGatewayDevice:1");
+	dev->set_igd_control_url(urls.controlURL);
+	dev->set_igd_service_type(data.first.servicetype);
+	dev->set_igd_our_addr(addr);
+	dev->set_igd_status(UPNPDevice::IGD_STATUS_OK);
+	FreeUPNPUrls(&urls);
+
+	devices.push_back(dev);
+
+	return UPNP_RESULT_SUCCESS;
+}
+
 void UPNP::add_device_to_list(UPNPDev *dev, UPNPDev *devlist) {
 	Ref<UPNPDevice> new_device;
 	new_device.instantiate();
@@ -343,6 +376,7 @@ void UPNP::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_gateway"), &UPNP::get_gateway);
 
 	ClassDB::bind_method(D_METHOD("discover", "timeout", "ttl", "device_filter"), &UPNP::discover, DEFVAL(2000), DEFVAL(2), DEFVAL("InternetGatewayDevice"));
+	ClassDB::bind_method(D_METHOD("add_device_from_url", "desc_url"), &UPNP::add_device_from_url);
 
 	ClassDB::bind_method(D_METHOD("query_external_address"), &UPNP::query_external_address);
 
diff --git a/modules/upnp/upnp.h b/modules/upnp/upnp.h
index be7ede3ee04..3fb5aa24d11 100644
--- a/modules/upnp/upnp.h
+++ b/modules/upnp/upnp.h
@@ -100,6 +100,7 @@ public:
 	Ref<UPNPDevice> get_gateway() const;
 
 	int discover(int timeout = 2000, int ttl = 2, const String &device_filter = "InternetGatewayDevice");
+	UPNPResult add_device_from_url(const String &desc_url);
 
 	String query_external_address() const;