[GStreamer][WebRTC] Rework UDP port ranges support

https://bugs.webkit.org/show_bug.cgi?id=281569

Reviewed by Xabier Rodriguez-Calvar.

This is a follow-up to 285190@main. The WebKit LibWebRTProvider changes in that revision were
incorrect, the provider doesn't have access to the core page from its constructor. The correct
approach to apply settings to the provider is to use the Page::settingsDidChange() method.

Also minPort or maxPort values of 0 are accepted by libwebrtc and mean they are unspecified, so we
should allow those values.

* Source/WebCore/page/Page.cpp:
(WebCore::Page::settingsDidChange):
* Source/WebCore/platform/mediastream/WebRTCProvider.cpp:
(WebCore::WebRTCProvider::setPortAllocatorRange):
* Source/WebKit/UIProcess/API/glib/WebKitSettings.cpp:
(webkit_settings_class_init):
* Source/WebKit/WebProcess/Network/webrtc/LibWebRTCProvider.cpp:
(WebKit::LibWebRTCProvider::LibWebRTCProvider):
* Tools/TestWebKitAPI/Tests/WebKitGLib/TestWebKitSettings.cpp:
(testWebKitSettings):

Canonical link: https://commits.webkit.org/285333@main

Author: philn

Source/WebCore/page/Page.cpp

@@ -597,6 +597,7 @@ void Page::settingsDidChange()
     m_webRTCProvider->setH265Support(settings().webRTCH265CodecEnabled());
     m_webRTCProvider->setVP9Support(settings().webRTCVP9Profile0CodecEnabled(), settings().webRTCVP9Profile2CodecEnabled());
     m_webRTCProvider->setAV1Support(settings().webRTCAV1CodecEnabled());
+    m_webRTCProvider->setPortAllocatorRange(settings().webRTCUDPPortRange());
 #endif
 }
 

Source/WebCore/platform/mediastream/WebRTCProvider.cpp

@@ -310,22 +310,38 @@ std::optional<MediaCapabilitiesEncodingInfo> WebRTCProvider::videoEncodingCapabi
 
 void WebRTCProvider::setPortAllocatorRange(StringView range)
 {
+    if (range.isEmpty())
+        return;
+
+    if (range == "0:0"_s)
+        return;
+
     auto components = range.toStringWithoutCopying().split(':');
     if (UNLIKELY(components.size() != 2)) {
         WTFLogAlways("Invalid format for UDP port range. Should be \"min-port:max-port\"");
         ASSERT_NOT_REACHED();
         return;
     }
 
-    auto minPort = WTF::parseInteger<int>(components[0]).value_or(0);
-    auto maxPort = WTF::parseInteger<int>(components[1]).value_or(0);
+    auto minPort = WTF::parseInteger<int>(components[0]);
+    auto maxPort = WTF::parseInteger<int>(components[1]);
     if (!minPort || !maxPort) {
         WTFLogAlways("Invalid format for UDP port range. Should be \"min-port:max-port\"");
         ASSERT_NOT_REACHED();
         return;
     }
 
-    m_portAllocatorRange = { { minPort, maxPort } };
+    if (*minPort < 0) {
+        WTFLogAlways("Invalid value for UDP minimum port value: %d", *minPort);
+        return;
+    }
+
+    if (*maxPort < 0) {
+        WTFLogAlways("Invalid value for UDP maximum port value: %d", *maxPort);
+        return;
+    }
+
+    m_portAllocatorRange = { { *minPort, *maxPort } };
 }
 
 std::optional<std::pair<int, int>> WebRTCProvider::portAllocatorRange() const

Source/WebKit/UIProcess/API/glib/WebKitSettings.cpp

@@ -1795,7 +1795,8 @@ static void webkit_settings_class_init(WebKitSettingsClass* klass)
      * In some constrained environments where a firewall blocks UDP network traffic excepted on a
      * specific port range, this settings can be used to give hints to the WebRTC backend regarding
      * which ports to allocate. The format is min-port:max-port, so for instance 20000:30000. The
-     * default value is 0:0 which means the OS will use no hints from the WebRTC backend.
+     * default empty string value means the OS will use no hints from the WebRTC backend. Using 0
+     * for one of the values is allowed and means the value is unspecified.
      *
      * Since: 2.48
      */

Source/WebKit/WebProcess/Network/webrtc/LibWebRTCProvider.cpp

@@ -73,12 +73,6 @@ LibWebRTCProvider::LibWebRTCProvider(WebPage& webPage)
 #else
     m_supportsMDNS = true;
 #endif
-
-    auto* page = webPage.corePage();
-    if (!page || !page->settings().webRTCUDPPortRange())
-        return;
-
-    setPortAllocatorRange(page->settings().webRTCUDPPortRange());
 }
 
 rtc::scoped_refptr<webrtc::PeerConnectionInterface> LibWebRTCProvider::createPeerConnection(ScriptExecutionContextIdentifier identifier, webrtc::PeerConnectionObserver& observer, rtc::PacketSocketFactory* socketFactory, webrtc::PeerConnectionInterface::RTCConfiguration&& configuration)

Tools/TestWebKitAPI/Tests/WebKitGLib/TestWebKitSettings.cpp

@@ -387,6 +387,10 @@ ALLOW_DEPRECATED_DECLARATIONS_END
     g_assert_cmpstr("", ==, webkit_settings_get_webrtc_udp_ports_range(settings));
     webkit_settings_set_webrtc_udp_ports_range(settings, "20000:30000");
     g_assert_cmpstr("20000:30000", ==, webkit_settings_get_webrtc_udp_ports_range(settings));
+    webkit_settings_set_webrtc_udp_ports_range(settings, "20000:0");
+    g_assert_cmpstr("20000:0", ==, webkit_settings_get_webrtc_udp_ports_range(settings));
+    webkit_settings_set_webrtc_udp_ports_range(settings, "0:20000");
+    g_assert_cmpstr("0:20000", ==, webkit_settings_get_webrtc_udp_ports_range(settings));
 #endif
 
     g_object_unref(G_OBJECT(settings));