1 files changed, 63 insertions, 0 deletions
diff --git a/image/ImageBlocker.cpp b/image/ImageBlocker.cpp
new file mode 100644
index 0000000000..c8ff1baaaf
--- /dev/null
+++ b/image/ImageBlocker.cpp
@@ -0,0 +1,63 @@
+/* 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/. */
+
+#include "ImageBlocker.h"
+#include "nsIPermissionManager.h"
+#include "nsContentUtils.h"
+#include "mozilla/StaticPrefs_permissions.h"
+#include "nsNetUtil.h"
+
+using namespace mozilla;
+using namespace mozilla::image;
+
+NS_IMPL_ISUPPORTS(ImageBlocker, nsIContentPolicy)
+
+NS_IMETHODIMP
+ImageBlocker::ShouldLoad(nsIURI* aContentLocation, nsILoadInfo* aLoadInfo,
+                         int16_t* aShouldLoad) {
+  *aShouldLoad = nsIContentPolicy::ACCEPT;
+
+  if (!aContentLocation) {
+    // Bug 1720280: Ideally we should block the load, but to avoid a potential
+    // null pointer deref, we return early in this case. Please note that
+    // the ImageBlocker only applies about http/https loads anyway.
+    return NS_OK;
+  }
+
+  ExtContentPolicyType contentType = aLoadInfo->GetExternalContentPolicyType();
+  if (contentType != ExtContentPolicy::TYPE_IMAGE &&
+      contentType != ExtContentPolicy::TYPE_IMAGESET) {
+    return NS_OK;
+  }
+
+  if (ImageBlocker::ShouldBlock(aContentLocation)) {
+    NS_SetRequestBlockingReason(
+        aLoadInfo, nsILoadInfo::BLOCKING_REASON_CONTENT_POLICY_CONTENT_BLOCKED);
+    *aShouldLoad = nsIContentPolicy::REJECT_TYPE;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ImageBlocker::ShouldProcess(nsIURI* aContentLocation, nsILoadInfo* aLoadInfo,
+                            int16_t* aShouldProcess) {
+  // We block images at load level already, so those should not end up here.
+  *aShouldProcess = nsIContentPolicy::ACCEPT;
+  return NS_OK;
+}
+
+/* static */
+bool ImageBlocker::ShouldBlock(nsIURI* aContentLocation) {
+  // Block loading images depending on the permissions.default.image pref.
+  if (StaticPrefs::permissions_default_image() !=
+      nsIPermissionManager::DENY_ACTION) {
+    return false;
+  }
+
+  // we only want to check http, https
+  // for chrome:// and resources and others, no need to check.
+  return aContentLocation->SchemeIs("http") ||
+         aContentLocation->SchemeIs("https");
+}