From fd4b32aa9ee3c822c44e7dc8728e9e87eb47a695 Mon Sep 17 00:00:00 2001
From: Valentin Gosu <valentin.gosu@gmail.com>
Date: Tue, 16 Jan 2024 09:22:16 +0000
Subject: [PATCH] Bug 1816390 - Partition the cache entries generated by
 cross-origin fetch requests r=necko-reviewers,kershaw,jesup

Differential Revision: https://phabricator.services.mozilla.com/D195757
---
 modules/libpref/init/StaticPrefList.yaml |  7 +++++++
 netwerk/protocol/http/nsHttpChannel.cpp  | 12 ++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
index c83537f17c8b..af2d6c7c384a 100644
--- a/modules/libpref/init/StaticPrefList.yaml
+++ b/modules/libpref/init/StaticPrefList.yaml
@@ -11429,6 +11429,13 @@
   value: true
   mirror: always
 
+# If true, cross origin fetch (or XHR) requests would be keyed
+# with a different cache key.
+- name: network.fetch.cache_partition_cross_origin
+  type: RelaxedAtomicBool
+  value: true
+  mirror: always
+
 # Whether to strip auth headers for redirected http channels
 # https://fetch.spec.whatwg.org/#http-redirect-fetch
 - name: network.http.redirect.stripAuthHeader
diff --git a/netwerk/protocol/http/nsHttpChannel.cpp b/netwerk/protocol/http/nsHttpChannel.cpp
index b6ed87b72738..9480bcf9b088 100644
--- a/netwerk/protocol/http/nsHttpChannel.cpp
+++ b/netwerk/protocol/http/nsHttpChannel.cpp
@@ -3762,6 +3762,18 @@ nsresult nsHttpChannel::OpenCacheEntryInternal(bool isHttps) {
   if (mRequestHead.IsHead()) {
     mCacheIdExtension.Append("HEAD");
   }
+  bool isThirdParty = false;
+  if (StaticPrefs::network_fetch_cache_partition_cross_origin() &&
+      (NS_FAILED(mLoadInfo->TriggeringPrincipal()->IsThirdPartyChannel(
+           this, &isThirdParty)) ||
+       isThirdParty) &&
+      (mLoadInfo->InternalContentPolicyType() == nsIContentPolicy::TYPE_FETCH ||
+       mLoadInfo->InternalContentPolicyType() ==
+           nsIContentPolicy::TYPE_XMLHTTPREQUEST ||
+       mLoadInfo->InternalContentPolicyType() ==
+           nsIContentPolicy::TYPE_INTERNAL_XMLHTTPREQUEST)) {
+    mCacheIdExtension.Append("FETCH");
+  }
 
   mCacheOpenWithPriority = cacheEntryOpenFlags & nsICacheStorage::OPEN_PRIORITY;
   mCacheQueueSizeWhenOpen =