Bug 1561443 - Expose error code string to about:neterror with webidl. r=baku

Differential Revision: https://phabricator.services.mozilla.com/D45540

--HG--
extra : moz-landing-system : lando

dom/base/Document.cpp

@@ -1380,6 +1380,64 @@ Document::Document(const char* aContentType)
   mReferrerInfo = new dom::ReferrerInfo(nullptr);
 }
 
+bool Document::CallerIsTrustedAboutNetError(JSContext* aCx, JSObject* aObject) {
+  nsIPrincipal* principal = nsContentUtils::SubjectPrincipal(aCx);
+  if (NS_WARN_IF(!principal)) {
+    return false;
+  }
+
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = NS_OK;
+  rv = principal->GetURI(getter_AddRefs(uri));
+  NS_ENSURE_SUCCESS(rv, false);
+
+  if (!uri) {
+    return false;
+  }
+
+  // getSpec is an expensive operation, hence we first check the scheme
+  // to see if the caller is actually an about: page.
+  if (!uri->SchemeIs("about")) {
+    return false;
+  }
+
+  nsAutoCString aboutSpec;
+  rv = uri->GetSpec(aboutSpec);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  return StringBeginsWith(aboutSpec, NS_LITERAL_CSTRING("about:neterror"));
+}
+
+void Document::GetNetErrorInfo(mozilla::dom::NetErrorInfo& aInfo,
+                               ErrorResult& aRv) {
+  nsCOMPtr<nsISupports> info;
+  nsCOMPtr<nsITransportSecurityInfo> tsi;
+  nsresult rv = NS_OK;
+  if (NS_WARN_IF(!mFailedChannel)) {
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return;
+  }
+
+  rv = mFailedChannel->GetSecurityInfo(getter_AddRefs(info));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    aRv.Throw(rv);
+    return;
+  }
+  tsi = do_QueryInterface(info);
+  if (NS_WARN_IF(!tsi)) {
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return;
+  }
+
+  nsAutoString errorCodeString;
+  rv = tsi->GetErrorCodeString(errorCodeString);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    aRv.Throw(rv);
+    return;
+  }
+  aInfo.mErrorCodeString.Assign(errorCodeString);
+}
+
 bool Document::CallerIsTrustedAboutCertError(JSContext* aCx,
                                              JSObject* aObject) {
   nsIPrincipal* principal = nsContentUtils::SubjectPrincipal(aCx);

dom/base/Document.h

@@ -66,6 +66,7 @@
 #include "mozilla/TimeStamp.h"
 #include "mozilla/UniquePtr.h"
 #include "mozilla/dom/FailedCertSecurityInfoBinding.h"
+#include "mozilla/dom/NetErrorInfoBinding.h"
 #include <bitset>  // for member
 
 // windows.h #defines CreateEvent
@@ -2500,6 +2501,18 @@ class Document : public nsINode,
    */
   nsIChannel* GetFailedChannel() const { return mFailedChannel; }
 
+  /**
+   * This function checks if the document that is trying to access
+   * GetNetErrorInfo is a trusted about net error page or not.
+   */
+  static bool CallerIsTrustedAboutNetError(JSContext* aCx, JSObject* aObject);
+
+  /**
+   * Get security info like error code for a failed channel. This
+   * property is only exposed to about:neterror documents.
+   */
+  void GetNetErrorInfo(mozilla::dom::NetErrorInfo& aInfo, ErrorResult& aRv);
+
   /**
    * This function checks if the document that is trying to access
    * GetFailedCertSecurityInfo is a trusted cert error page or not.

dom/webidl/Document.webidl

@@ -322,6 +322,11 @@ partial interface Document {
   FailedCertSecurityInfo getFailedCertSecurityInfo();
 };
 
+partial interface Document {
+  [Func="Document::CallerIsTrustedAboutNetError", Throws]
+  NetErrorInfo getNetErrorInfo();
+};
+
 // https://w3c.github.io/page-visibility/#extensions-to-the-document-interface
 partial interface Document {
   readonly attribute boolean hidden;

dom/webidl/NetErrorInfo.webidl

@@ -0,0 +1,14 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+/**
+ * This dictionary is used for exposing failed channel info
+ * to about:neterror to built UI.
+ */
+
+dictionary NetErrorInfo {
+  DOMString errorCodeString = "";
+};

dom/webidl/moz.build

@@ -686,6 +686,7 @@ WEBIDL_FILES = [
     'NativeOSFileInternals.webidl',
     'Navigator.webidl',
     'NetDashboard.webidl',
+    'NetErrorInfo.webidl',
     'NetworkInformation.webidl',
     'NetworkOptions.webidl',
     'NodeFilter.webidl',