Bug 1540810 - Part 1: Add a cookie settings API for partitioning third-party content; r=baku

Differential Revision: https://phabricator.services.mozilla.com/D54572

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

dom/base/Document.cpp

@@ -16000,7 +16000,13 @@ nsICookieSettings* Document::CookieSettings() {
   // If we are here, this is probably a javascript: URL document. In any case,
   // we must have a nsCookieSettings. Let's create it.
   if (!mCookieSettings) {
-    mCookieSettings = net::CookieSettings::Create();
+    Document* inProcessParent = GetInProcessParentDocument();
+
+    mCookieSettings =
+        inProcessParent
+            ? net::CookieSettings::Create(
+                  inProcessParent->CookieSettings()->GetCookieBehavior())
+            : net::CookieSettings::Create();
   }
 
   return mCookieSettings;

netwerk/cookie/CookieSettings.cpp

@@ -81,6 +81,16 @@ already_AddRefed<nsICookieSettings> CookieSettings::Create() {
   return cookieSettings.forget();
 }
 
+// static
+already_AddRefed<nsICookieSettings> CookieSettings::Create(
+    uint32_t aCookieBehavior) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  RefPtr<CookieSettings> cookieSettings =
+      new CookieSettings(aCookieBehavior, eProgressive);
+  return cookieSettings.forget();
+}
+
 CookieSettings::CookieSettings(uint32_t aCookieBehavior, State aState)
     : mCookieBehavior(aCookieBehavior), mState(aState), mToBeMerged(false) {
   MOZ_ASSERT(NS_IsMainThread());
@@ -124,6 +134,23 @@ CookieSettings::GetLimitForeignContexts(bool* aLimitForeignContexts) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+CookieSettings::GetPartitionForeign(bool* aPartitionForeign) {
+  *aPartitionForeign =
+      mCookieBehavior ==
+      nsICookieService::BEHAVIOR_REJECT_TRACKER_AND_PARTITION_FOREIGN;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CookieSettings::SetPartitionForeign(bool aPartitionForeign) {
+  if (aPartitionForeign) {
+    mCookieBehavior =
+        nsICookieService::BEHAVIOR_REJECT_TRACKER_AND_PARTITION_FOREIGN;
+  }
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 CookieSettings::CookiePermission(nsIPrincipal* aPrincipal,
                                  uint32_t* aCookiePermission) {
@@ -262,12 +289,36 @@ void CookieSettings::Serialize(CookieSettingsArgs& aData) {
 
 void CookieSettings::Merge(const CookieSettingsArgs& aData) {
   MOZ_ASSERT(NS_IsMainThread());
-  MOZ_ASSERT(mCookieBehavior == aData.cookieBehavior());
+  MOZ_ASSERT(
+      mCookieBehavior == aData.cookieBehavior() ||
+      (mCookieBehavior == nsICookieService::BEHAVIOR_REJECT_TRACKER &&
+       aData.cookieBehavior() ==
+           nsICookieService::BEHAVIOR_REJECT_TRACKER_AND_PARTITION_FOREIGN) ||
+      (mCookieBehavior ==
+           nsICookieService::BEHAVIOR_REJECT_TRACKER_AND_PARTITION_FOREIGN &&
+       aData.cookieBehavior() == nsICookieService::BEHAVIOR_REJECT_TRACKER));
 
   if (mState == eFixed) {
     return;
   }
 
+  // Merge cookie behavior pref values
+  if (mCookieBehavior == nsICookieService::BEHAVIOR_REJECT_TRACKER &&
+      aData.cookieBehavior() ==
+          nsICookieService::BEHAVIOR_REJECT_TRACKER_AND_PARTITION_FOREIGN) {
+    // If the other side has decided to partition third-party cookies, update
+    // our side.
+    mCookieBehavior =
+        nsICookieService::BEHAVIOR_REJECT_TRACKER_AND_PARTITION_FOREIGN;
+  }
+  if (mCookieBehavior ==
+          nsICookieService::BEHAVIOR_REJECT_TRACKER_AND_PARTITION_FOREIGN &&
+      aData.cookieBehavior() == nsICookieService::BEHAVIOR_REJECT_TRACKER) {
+    // If we've decided to partition third-party cookies, the other side may not
+    // have caught up yet.  Do nothing.
+  }
+  // Ignore all other cases.
+
   PermissionComparator comparator;
 
   for (const CookiePermissionData& data : aData.cookiePermissions()) {

netwerk/cookie/CookieSettings.h

@@ -113,6 +113,8 @@ class CookieSettings final : public nsICookieSettings {
 
   static already_AddRefed<nsICookieSettings> Create();
 
+  static already_AddRefed<nsICookieSettings> Create(uint32_t aCookieBehavior);
+
   static CookieSettings* Cast(nsICookieSettings* aCS) {
     return static_cast<CookieSettings*>(aCS);
   }

netwerk/cookie/nsICookieSettings.idl

@@ -28,6 +28,11 @@ interface nsICookieSettings : nsISupports
 
   [infallible] readonly attribute boolean limitForeignContexts;
 
+  /**
+   * Whether our cookie behavior mandates partitioning third-party content.
+   */
+  [infallible] attribute boolean partitionForeign;
+
   /**
    * CookiePermission at the loading of the document for a particular
    * principal. It returns the same cookiePermission also in case it changes