Remove all headers referred to by 'Connection'

Author: Lukasa

HISTORY.rst

@@ -1,6 +1,13 @@
 Release History
 ===============
 
+Upcoming
+--------
+
+*Minor Changes*
+
+- We not only remove the Connection header but all headers it refers to.
+
 0.2.0 (2015-02-07)
 ------------------
 

hyper/http20/connection.py

@@ -277,14 +277,6 @@ def putheader(self, header, argument, stream_id=None):
         :returns: Nothing.
         """
         stream = self._get_stream(stream_id)
-
-        # Initially, strip the Connection header. Note that we do this after
-        # the call to `_get_stream` to ensure that we don't accidentally hide
-        # bugs just because the user sent a connection header.
-        if header.lower() == 'connection':
-            log.debug('Ignoring connection header with value %s', argument)
-            return
-
         stream.add_header(header, argument)
 
         return

hyper/http20/stream.py

@@ -18,7 +18,7 @@
     FRAME_MAX_LEN, FRAMES, HeadersFrame, DataFrame, PushPromiseFrame,
     WindowUpdateFrame, ContinuationFrame, BlockedFrame
 )
-from .util import get_from_key_value_set
+from .util import get_from_key_value_set, h2_safe_headers
 import collections
 import logging
 import zlib
@@ -250,8 +250,10 @@ def open(self, end):
         The `end` flag controls whether this will be the end of the stream, or
         whether data will follow.
         """
+        # Strip any headers invalid in H2.
+        headers = h2_safe_headers(self.headers)
         # Encode the headers.
-        encoded_headers = self._encoder.encode(self.headers)
+        encoded_headers = self._encoder.encode(headers)
 
         # It's possible that there is a substantial amount of data here. The
         # data needs to go into one HEADERS frame, followed by a number of

hyper/http20/util.py

@@ -74,3 +74,17 @@ def split_repeated_headers(kvset):
         headers[key] = value.split(b'\x00')
 
     return dict(headers)
+
+
+def h2_safe_headers(headers):
+    """
+    This method takes a set of headers that are provided by the user and
+    transforms them into a form that is safe for emitting over HTTP/2.
+
+    Currently, this strips the Connection header and any header it refers to.
+    """
+    stripped = {i.lower().strip() for k, v in headers if k == 'connection'
+                                  for i in v.split(',')}
+    stripped.add('connection')
+
+    return [header for header in headers if header[0] not in stripped]

test/test_hyper.py

@@ -16,7 +16,9 @@
     HPACKDecodingError, HPACKEncodingError, ProtocolError
 )
 from hyper.http20.window import FlowControlManager
-from hyper.http20.util import combine_repeated_headers, split_repeated_headers
+from hyper.http20.util import (
+    combine_repeated_headers, split_repeated_headers, h2_safe_headers
+)
 from hyper.compat import zlib_compressobj
 from hyper.contrib import HTTP20Adapter
 import errno
@@ -1011,20 +1013,6 @@ def test_putheader_puts_headers(self):
             ('name', 'value'),
         ]
 
-    def test_putheader_ignores_connection(self):
-        c = HTTP20Connection("www.google.com")
-
-        c.putrequest('GET', '/')
-        c.putheader('Connection', 'keep-alive')
-        s = c.recent_stream
-
-        assert s.headers == [
-            (':method', 'GET'),
-            (':scheme', 'https'),
-            (':authority', 'www.google.com'),
-            (':path', '/'),
-        ]
-
     def test_endheaders_sends_data(self):
         frames = []
 
@@ -2048,6 +2036,32 @@ def test_nghttp2_installs_correctly(self):
 
         assert True
 
+    def test_stripping_connection_header(self):
+        headers = [('one', 'two'), ('connection', 'close')]
+        stripped = [('one', 'two')]
+
+        assert h2_safe_headers(headers) == stripped
+
+    def test_stripping_related_headers(self):
+        headers = [
+            ('one', 'two'), ('three', 'four'), ('five', 'six'),
+            ('connection', 'close, three, five')
+        ]
+        stripped = [('one', 'two')]
+
+        assert h2_safe_headers(headers) == stripped
+
+    def test_stripping_multiple_connection_headers(self):
+        headers = [
+            ('one', 'two'), ('three', 'four'), ('five', 'six'),
+            ('connection', 'close'),
+            ('connection', 'three, five')
+        ]
+        stripped = [('one', 'two')]
+
+        assert h2_safe_headers(headers) == stripped
+
+
 # Some utility classes for the tests.
 class NullEncoder(object):
     @staticmethod