Changeset 188690 in webkit

Timestamp:

Aug 20, 2015 10:47:08 AM (9 years ago)

Author:

Chris Dumez

Message:

[Cocoa] Treat Epoch as invalid value for "Last-Modified" header
​https://bugs.webkit.org/show_bug.cgi?id=148162
rdar://problem/22330837

Reviewed by Antti Koivisto.

Source/WebCore:

Ignore "Last-Modified" header when computing heuristic freshness if it
is Epoch. CFNetwork currently converts a malformed date for Last-Modified
into Epoch so there is no way for us to distinguish Epoch from invalid
input. Without this, we would end up with cached resources that have a
giant lifetime (> 4 years) due to a malformed HTTP header.

Some Websites (e.g. www.popehat.com) also wrongly return Epoch as
Last-Modified value and we would end up caching it overly aggressively.
Now that we consider Epoch as an invalid value for Last-Modified, it will
also work around this content bug.

Test: http/tests/cache/disk-cache/disk-cache-last-modified.html

• platform/network/ResourceResponseBase.cpp:

(WebCore::ResourceResponseBase::lastModified):

LayoutTests:

Add better layout test coverage for using the "Last-Modified" header to
compute heuristic freshness. In particular, it adds coverage for the
following values: Epoch, malformed date.

• http/tests/cache/disk-cache/disk-cache-last-modified-expected.txt: Added.
• http/tests/cache/disk-cache/disk-cache-last-modified.html: Added.

New test.

• http/tests/cache/disk-cache/resources/cache-test.js:

(makeHeaderValue):
makeHeaderValue() was not resolving 'now(-1000)' into a date. This means that the
tests using it would end up sending an invalid "Last-Modified" header which our
networking code was translating to Epoch. We now ignore Epoch as Last-Modified
value for computing heuristic freshness to not cache due to malformed headers.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/http/tests/cache/disk-cache/disk-cache-last-modified-expected.txt (added)
• LayoutTests/http/tests/cache/disk-cache/disk-cache-last-modified.html (added)
• LayoutTests/http/tests/cache/disk-cache/resources/cache-test.js (modified) (1 diff)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/platform/network/ResourceResponseBase.cpp (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2015-08-20  Chris Dumez  <cdumez@apple.com>
+
+        [Cocoa] Treat Epoch as invalid value for "Last-Modified" header
+        https://bugs.webkit.org/show_bug.cgi?id=148162
+        rdar://problem/22330837
+
+        Reviewed by Antti Koivisto.
+
+        Add better layout test coverage for using the "Last-Modified" header to
+        compute heuristic freshness. In particular, it adds coverage for the
+        following values: Epoch, malformed date.
+
+        * http/tests/cache/disk-cache/disk-cache-last-modified-expected.txt: Added.
+        * http/tests/cache/disk-cache/disk-cache-last-modified.html: Added.
+        New test.
+
+        * http/tests/cache/disk-cache/resources/cache-test.js:
+        (makeHeaderValue):
+        makeHeaderValue() was not resolving 'now(-1000)' into a date. This means that the
+        tests using it would end up sending an invalid "Last-Modified" header which our
+        networking code was translating to Epoch. We now ignore Epoch as Last-Modified
+        value for computing heuristic freshness to not cache due to malformed headers.
+
 2015-08-20  Eric Carlson  <eric.carlson@apple.com>
 

trunk/LayoutTests/http/tests/cache/disk-cache/resources/cache-test.js

@@ -34 +34 @@
     if (value == 'now(100)')
         return (new Date(new Date().getTime() + serverClientTimeDelta + 100 * 1000)).toUTCString();
+    if (value == 'now(-1000)')
+        return (new Date(new Date().getTime() - serverClientTimeDelta - 1000 * 1000)).toUTCString()
     if (value == 'unique()')
         return "" + uniqueIdCounter++;

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2015-08-20  Chris Dumez  <cdumez@apple.com>
+
+        [Cocoa] Treat Epoch as invalid value for "Last-Modified" header
+        https://bugs.webkit.org/show_bug.cgi?id=148162
+        rdar://problem/22330837
+
+        Reviewed by Antti Koivisto.
+
+        Ignore "Last-Modified" header when computing heuristic freshness if it
+        is Epoch. CFNetwork currently converts a malformed date for Last-Modified
+        into Epoch so there is no way for us to distinguish Epoch from invalid
+        input. Without this, we would end up with cached resources that have a
+        giant lifetime (> 4 years) due to a malformed HTTP header.
+
+        Some Websites (e.g. www.popehat.com) also wrongly return Epoch as
+        Last-Modified value and we would end up caching it overly aggressively.
+        Now that we consider Epoch as an invalid value for Last-Modified, it will
+        also work around this content bug.
+
+        Test: http/tests/cache/disk-cache/disk-cache-last-modified.html
+
+        * platform/network/ResourceResponseBase.cpp:
+        (WebCore::ResourceResponseBase::lastModified):
+
 2015-08-19  Brian Burg  <bburg@apple.com>
 

trunk/Source/WebCore/platform/network/ResourceResponseBase.cpp

@@ -426 +426 @@
     if (!m_haveParsedLastModifiedHeader) {
         m_lastModified = parseDateValueInHeader(m_httpHeaderFields, HTTPHeaderName::LastModified);
+#if PLATFORM(COCOA)
+        // CFNetwork converts malformed dates into Epoch so we need to treat Epoch as
+        // an invalid value (rdar://problem/22352838).
+        const std::chrono::system_clock::time_point epoch;
+        if (m_lastModified && m_lastModified.value() == epoch)
+            m_lastModified = Nullopt;
+#endif
         m_haveParsedLastModifiedHeader = true;
     }