Remote Web Inspector: Send the presentingApplicationPID to the rela…

…y process for WKWebViews

https://bugs.webkit.org/show_bug.cgi?id=254537
rdar://105636143

Reviewed by BJ Burg.

In some cases, a process may create WKWebViews on behalf of another process to be served remotely. WKWebViews
inspectability is managed in the UI process, and those does not currently use the `presentingApplicationPID` to
associate a target with a specific parent process (a process may represent multiple parent processes at a time). We thus
need to provide target-specific PIDs for the presenting application so that WKWebViews are correctly related back to the
application that is showing the web content via the intermediate remote service that actually created the WKWebView.

* Source/JavaScriptCore/inspector/remote/RemoteInspectionTarget.cpp:
(Inspector::RemoteInspectionTarget::setPresentingApplicationPID):
* Source/JavaScriptCore/inspector/remote/RemoteInspectionTarget.h:
- Allow setting a per-target `presentingApplicationPID` as an alternative to having a single PID the entire process
proxies its inspectable content to.

* Source/JavaScriptCore/inspector/remote/cocoa/RemoteInspectorCocoa.mm:
(Inspector::identifierForPID):
(Inspector::RemoteInspector::listingForInspectionTarget const):
- Provide a per-target presenting application PID so that individual web views can be associated the appropriate process.
Relays should use this value in place of the application-wide parent process PID when it is present. For WKWebView,
those values will be equal by default unless explicitly set.

(Inspector::RemoteInspector::receivedProxyApplicationSetupMessage):
- Proxy apps don't need to respond to the proxy setup message, since all the necessary information will be provided with
the application's listing of targets.

* Source/WebKit/UIProcess/WebPageProxy.cpp:
- Use the `presentingApplicationPID` of the web content process pool to inform associate the inspectable page with the
correct parent application, since that is the pool that the content to be inspected will actually exist in. Unless it
has been overriden, this will be the PID of the UI process.

Canonical link: https://commits.webkit.org/262620@main

Source/JavaScriptCore/inspector/remote/RemoteInspectionTarget.cpp

@@ -111,6 +111,14 @@ void RemoteInspectionTarget::unpauseForInitializedInspector()
     RemoteInspector::singleton().setupCompleted(targetIdentifier());
 }
 
+void RemoteInspectionTarget::setPresentingApplicationPID(std::optional<ProcessID>&& pid)
+{
+    m_presentingApplicationPID = pid;
+#if PLATFORM(COCOA)
+    RemoteInspector::singleton().setUsePerTargetPresentingApplicationPIDs(true);
+#endif
+}
+
 } // namespace Inspector
 
 #endif // ENABLE(REMOTE_INSPECTOR)

Source/JavaScriptCore/inspector/remote/RemoteInspectionTarget.h

@@ -29,6 +29,7 @@
 
 #include "JSRemoteInspector.h"
 #include "RemoteControllableTarget.h"
+#include <wtf/ProcessID.h>
 #include <wtf/RetainPtr.h>
 #include <wtf/TypeCasts.h>
 #include <wtf/text/WTFString.h>
@@ -62,6 +63,9 @@ class JS_EXPORT_PRIVATE RemoteInspectionTarget : public RemoteControllableTarget
     // RemoteControllableTarget overrides.
     bool remoteControlAllowed() const final;
 
+    std::optional<ProcessID> presentingApplicationPID() const { return m_presentingApplicationPID; }
+    void setPresentingApplicationPID(std::optional<ProcessID>&&);
+
 private:
     enum class Inspectable : uint8_t {
         Yes,
@@ -76,6 +80,8 @@ class JS_EXPORT_PRIVATE RemoteInspectionTarget : public RemoteControllableTarget
 #if USE(CF)
     RetainPtr<CFRunLoopRef> m_runLoop;
 #endif
+
+    std::optional<ProcessID> m_presentingApplicationPID;
 };
 
 } // namespace Inspector

Source/JavaScriptCore/inspector/remote/RemoteInspector.h

@@ -159,6 +159,9 @@ class JS_EXPORT_PRIVATE RemoteInspector final
     void setParentProcessInformation(ProcessID, RetainPtr<CFDataRef> auditData);
     void setParentProcessInfomationIsDelayed();
     std::optional<audit_token_t> parentProcessAuditToken();
+
+    void setUsePerTargetPresentingApplicationPIDs(bool usePerTargetPresentingApplicationPIDs) { m_usePerTargetPresentingApplicationPIDs = usePerTargetPresentingApplicationPIDs; }
+
     bool isSimulatingCustomerInstall() const { return m_simulateCustomerInstall; }
 #endif
 
@@ -308,6 +311,7 @@ class JS_EXPORT_PRIVATE RemoteInspector final
     RetainPtr<CFDataRef> m_parentProcessAuditData;
     bool m_messageDataTypeChunkSupported { false };
     bool m_simulateCustomerInstall { false };
+    bool m_usePerTargetPresentingApplicationPIDs { false };
 #endif
     bool m_shouldSendParentProcessInformation { false };
     bool m_automaticInspectionEnabled WTF_GUARDED_BY_LOCK(m_mutex) { false };

Source/JavaScriptCore/inspector/remote/cocoa/RemoteInspectorCocoa.mm

@@ -453,6 +453,12 @@ static bool canAccessWebInspectorMachPort()
 
 #pragma mark - Listings
 
+static NSString* identifierForPID(ProcessID pid)
+{
+    // This format matches that used in the relay process.
+    return [NSString stringWithFormat:@"PID:%lu", (unsigned long)pid];
+}
+
 RetainPtr<NSDictionary> RemoteInspector::listingForInspectionTarget(const RemoteInspectionTarget& target) const
 {
     // Must collect target information on the WebThread, Main, or Worker thread since RemoteTargets are
@@ -493,6 +499,9 @@ static bool canAccessWebInspectorMachPort()
         break;
     }
 
+    if (auto presentingApplicationPID = target.presentingApplicationPID())
+        [listing setObject:identifierForPID(presentingApplicationPID.value()) forKey:WIRHostApplicationIdentifierKey];
+
     if (auto* connectionToTarget = m_targetConnectionMap.get(target.targetIdentifier()))
         [listing setObject:connectionToTarget->connectionIdentifier() forKey:WIRConnectionIdentifierKey];
 
@@ -722,6 +731,11 @@ static bool canAccessWebInspectorMachPort()
     if (!m_relayConnection)
         return;
 
+    // Proxy applications using per-target `presentingApplicationPID`s do not require any additional setup. The remote
+    // relay will complete its setup when the inspectable target listing is sent to it.
+    if (m_usePerTargetPresentingApplicationPIDs)
+        return;
+
     if (!m_parentProcessIdentifier || !m_parentProcessAuditData) {
         // We are a proxy application without parent process information.
         // Wait a bit for the information, but give up after a second.

Source/WebKit/UIProcess/WebPageProxy.cpp

@@ -580,6 +580,7 @@ WebPageProxy::WebPageProxy(PageClient& pageClient, WebProcessProxy& process, Ref
 
 #if ENABLE(REMOTE_INSPECTOR)
     m_inspectorDebuggable->setInspectable(JSRemoteInspectorGetInspectionEnabledByDefault());
+    m_inspectorDebuggable->setPresentingApplicationPID(m_process->processPool().configuration().presentingApplicationPID());
     m_inspectorDebuggable->init();
 #endif
     m_inspectorController->init();