Implement padding for SPDY4/HTTP2 DATA frames.

net/spdy/spdy_protocol.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file contains some protocol structures for use with SPDY 2 and 3
 // The SPDY 2 spec can be found at:
 // http://dev.chromium.org/spdy/spdy-protocol/spdy-protocol-draft2
 // The SPDY 3 spec can be found at:
 // http://dev.chromium.org/spdy/spdy-protocol/spdy-protocol-draft3
 
@@ skipping 273 matching lines @@
   WINDOW_UPDATE,
   CREDENTIAL,  // No longer valid.  Kept for identifiability/enum order.
   BLOCKED,
   PUSH_PROMISE,
   CONTINUATION,
   LAST_CONTROL_TYPE = CONTINUATION
 };
 
 // Flags on data packets.
 enum SpdyDataFlags {
-  DATA_FLAG_NONE = 0,
-  DATA_FLAG_FIN = 1,
+DATA_FLAG_NONE = 0x00,
+  DATA_FLAG_FIN = 0x01,
+  DATA_FLAG_END_SEGMENT = 0x02,
+  DATA_FLAG_PAD_LOW = 0x10,
+  DATA_FLAG_PAD_HIGH = 0x20
 };
 
 // Flags on control packets
 enum SpdyControlFlags {
   CONTROL_FLAG_NONE = 0,
   CONTROL_FLAG_FIN = 1,
   CONTROL_FLAG_UNIDIRECTIONAL = 2
 };
 
 enum SpdyPingFlags {
@@ skipping 170 matching lines @@
   // Performs deep copy on data.
   SpdyDataIR(SpdyStreamId stream_id, const base::StringPiece& data);
 
   // Use in conjunction with SetDataShallow() for shallow-copy on data.
   explicit SpdyDataIR(SpdyStreamId stream_id);
 
   virtual ~SpdyDataIR();
 
   base::StringPiece data() const { return data_; }
 
+  bool pad_low() const { return pad_low_; }
+
+  bool pad_high() const { return pad_high_; }
+
+  int padding_payload_len() const { return padding_payload_len_; }
+
+  void set_padding_len(int padding_len) {
+    // The padding_len should be in (0, 65535 + 2].
+    // Note that SpdyFramer::GetDataFrameMaximumPayload() enforces the overall
+    // payload size later so we actually can't pad more than 16375 bytes.
+    DCHECK_GT(padding_len, 0);
+    DCHECK_LT(padding_len, 65537);
+
+    if (padding_len <= 256) {
+      pad_low_ = true;
+      --padding_len;
+    } else {
+      pad_low_ = pad_high_ = true;
+      padding_len -= 2;
+    }
+    padding_payload_len_ = padding_len;
+  }
+
   // Deep-copy of data (keep private copy).
   void SetDataDeep(const base::StringPiece& data) {
     data_store_.reset(new std::string(data.data(), data.length()));
     data_ = *(data_store_.get());
   }
 
   // Shallow-copy of data (do not keep private copy).
   void SetDataShallow(const base::StringPiece& data) {
     data_store_.reset();
     data_ = data;
   }
 
   virtual void Visit(SpdyFrameVisitor* visitor) const OVERRIDE;
 
  private:
   // Used to store data that this SpdyDataIR should own.
   scoped_ptr<std::string> data_store_;
   base::StringPiece data_;
 
+  bool pad_low_;
+  bool pad_high_;
+  // padding_payload_len_ = desired padding length - len(padding length field).
+  int padding_payload_len_;
+
   DISALLOW_COPY_AND_ASSIGN(SpdyDataIR);
 };
 
 class NET_EXPORT_PRIVATE SpdySynStreamIR
     : public SpdyFrameWithNameValueBlockIR {
  public:
   explicit SpdySynStreamIR(SpdyStreamId stream_id)
       : SpdyFrameWithNameValueBlockIR(stream_id),
         associated_to_stream_id_(0),
         priority_(0),
@@ skipping 324 matching lines @@
   SpdyFrameVisitor() {}
   virtual ~SpdyFrameVisitor() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SpdyFrameVisitor);
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_PROTOCOL_H_