Allow fixed (non-negotiated) values to be sent in QUIC CHLO/SHLO. Also

net/quic/quic_config.h

Index: net/quic/quic_config.h
diff --git a/net/quic/quic_config.h b/net/quic/quic_config.h
index 7bba457ff51d59db318acbfcb63b332fcd0a2a4b..b522768ab7b20ef6e0ce681e87e303b22af66025 100644
--- a/net/quic/quic_config.h
+++ b/net/quic/quic_config.h
@@ -15,33 +15,62 @@ namespace net {
 
 class CryptoHandshakeMessage;
 
-class NET_EXPORT_PRIVATE QuicNegotiableValue {
+// Describes whether or not a given QuicTag is required or optional in the
+// handshake message.
+enum QuicConfigPresence {
+  // This value can be absent from the handshake message. Default value is
+  // selected as the negotiated value in such a case.
+  PRESENCE_OPTIONAL,
+  // This value is required in the handshake message otherwise the Process*Hello
+  // function returns an error.
+  PRESENCE_REQUIRED,
+};
+
+// An abstract base class that stores a value that can be sent in CHLO/SHLO
+// message. These values can be OPTIONAL or REQUIRED, depending on |presence_|.
+class NET_EXPORT_PRIVATE  QuicConfigValue {
  public:
-  enum Presence {
-    // This negotiable value can be absent from the handshake message. Default
-    // value is selected as the negotiated value in such a case.
-    PRESENCE_OPTIONAL,
-    // This negotiable value is required in the handshake message otherwise the
-    // Process*Hello function returns an error.
-    PRESENCE_REQUIRED,
-  };
+  QuicConfigValue(QuicTag tag, QuicConfigPresence presence);
+  virtual ~QuicConfigValue();
+
+  // Serialises tag name and value(s) to |out|.
+  virtual void ToHandshakeMessage(CryptoHandshakeMessage* out) const = 0;
+
+  // Selects a mutually acceptable value from those offered in |client_hello|
+  // and those defined in the subclass.
+  virtual QuicErrorCode ProcessClientHello(
+      const CryptoHandshakeMessage& client_hello,
+      std::string* error_details) = 0;
+
+  // Selects a mutually acceptable value from those offered in |server_hello|
+  // and those defined in the subclass.
+  virtual QuicErrorCode ProcessServerHello(
+      const CryptoHandshakeMessage& server_hello,
+      std::string* error_details) = 0;
 
-  QuicNegotiableValue(QuicTag tag, Presence presence);
+ protected:
+  const QuicTag tag_;
+  const QuicConfigPresence presence_;
+};
+
+class NET_EXPORT_PRIVATE QuicNegotiableValue : public QuicConfigValue {
+ public:
+  QuicNegotiableValue(QuicTag tag, QuicConfigPresence presence);
+  virtual ~QuicNegotiableValue();
 
   bool negotiated() const {
     return negotiated_;
   }
 
  protected:
-  const QuicTag tag_;
-  const Presence presence_;
   bool negotiated_;
 };
 
 class NET_EXPORT_PRIVATE QuicNegotiableUint32 : public QuicNegotiableValue {
  public:
   // Default and max values default to 0.
-  QuicNegotiableUint32(QuicTag name, Presence presence);
+  QuicNegotiableUint32(QuicTag name, QuicConfigPresence presence);
+  virtual ~QuicNegotiableUint32();
 
   // Sets the maximum possible value that can be achieved after negotiation and
   // also the default values to be assumed if PRESENCE_OPTIONAL and the *HLO msg
@@ -55,30 +84,25 @@ class NET_EXPORT_PRIVATE QuicNegotiableUint32 : public QuicNegotiableValue {
 
   // Serialises |name_| and value to |out|. If |negotiated_| is true then
   // |negotiated_value_| is serialised, otherwise |max_value_| is serialised.
-  void ToHandshakeMessage(CryptoHandshakeMessage* out) const;
+  virtual void ToHandshakeMessage(CryptoHandshakeMessage* out) const OVERRIDE;
 
   // Sets |negotiated_value_| to the minimum of |max_value_| and the
   // corresponding value from |client_hello|. If the corresponding value is
   // missing and PRESENCE_OPTIONAL then |negotiated_value_| is set to
   // |default_value_|.
-  QuicErrorCode ProcessClientHello(const CryptoHandshakeMessage& client_hello,
-                                   std::string* error_details);
+  virtual QuicErrorCode ProcessClientHello(
+      const CryptoHandshakeMessage& client_hello,
+      std::string* error_details) OVERRIDE;
 
   // Sets the |negotiated_value_| to the corresponding value from
   // |server_hello|. Returns error if the value received in |server_hello| is
   // greater than |max_value_|. If the corresponding value is missing and
   // PRESENCE_OPTIONAL then |negotiated_value_| is set to |0|,
-  QuicErrorCode ProcessServerHello(const CryptoHandshakeMessage& server_hello,
-                                   std::string* error_details);
+  virtual QuicErrorCode ProcessServerHello(
+      const CryptoHandshakeMessage& server_hello,
+      std::string* error_details) OVERRIDE;
 
  private:
-  // Reads the value corresponding to |name_| from |msg| into |out|. If the
-  // |name_| is absent in |msg| and |presence_| is set to OPTIONAL |out| is set
-  // to |max_value_|.
-  QuicErrorCode ReadUint32(const CryptoHandshakeMessage& msg,
-                           uint32* out,
-                           std::string* error_details) const;
-
   uint32 max_value_;
   uint32 default_value_;
   uint32 negotiated_value_;
@@ -86,8 +110,8 @@ class NET_EXPORT_PRIVATE QuicNegotiableUint32 : public QuicNegotiableValue {
 
 class NET_EXPORT_PRIVATE QuicNegotiableTag : public QuicNegotiableValue {
  public:
-  QuicNegotiableTag(QuicTag name, Presence presence);
-  ~QuicNegotiableTag();
+  QuicNegotiableTag(QuicTag name, QuicConfigPresence presence);
+  virtual ~QuicNegotiableTag();
 
   // Sets the possible values that |negotiated_tag_| can take after negotiation
   // and the default value that |negotiated_tag_| takes if OPTIONAL and *HLO
@@ -101,19 +125,21 @@ class NET_EXPORT_PRIVATE QuicNegotiableTag : public QuicNegotiableValue {
   // Serialises |name_| and vector (either possible or negotiated) to |out|. If
   // |negotiated_| is true then |negotiated_tag_| is serialised, otherwise
   // |possible_values_| is serialised.
-  void ToHandshakeMessage(CryptoHandshakeMessage* out) const;
+  virtual void ToHandshakeMessage(CryptoHandshakeMessage* out) const OVERRIDE;
 
   // Selects the tag common to both tags in |client_hello| for |name_| and
   // |possible_values_| with preference to tag in |possible_values_|. The
   // selected tag is set as |negotiated_tag_|.
-  QuicErrorCode ProcessClientHello(const CryptoHandshakeMessage& client_hello,
-                                   std::string* error_details);
+  virtual QuicErrorCode ProcessClientHello(
+      const CryptoHandshakeMessage& client_hello,
+      std::string* error_details) OVERRIDE;
 
   // Sets the value for |name_| tag in |server_hello| as |negotiated_value_|.
   // Returns error if the value received in |server_hello| isn't present in
   // |possible_values_|.
-  QuicErrorCode ProcessServerHello(const CryptoHandshakeMessage& server_hello,
-                                   std::string* error_details);
+  virtual QuicErrorCode ProcessServerHello(
+      const CryptoHandshakeMessage& server_hello,
+      std::string* error_details) OVERRIDE;
 
  private:
   // Reads the vector corresponding to |name_| from |msg| into |out|. If the
@@ -129,6 +155,36 @@ class NET_EXPORT_PRIVATE QuicNegotiableTag : public QuicNegotiableValue {
   QuicTag default_value_;
 };
 
+// Stores uint32 from CHLO or SHLO messages that are not negotiated.
+class QuicFixedUint32 : public QuicConfigValue {
+ public:
+  QuicFixedUint32(QuicTag name,
+                  QuicConfigPresence presence,
+                  uint32 default_value);
+  virtual ~QuicFixedUint32();
+
+  // Returns the value in the *HLO message (or the default if not).
+  uint32 GetUint32() const;
+
+  void set_value(uint32 value) { value_ = value; }
+
+  // Serialises |name_| and |value_| to |out|.
+  virtual void ToHandshakeMessage(CryptoHandshakeMessage* out) const OVERRIDE;
+
+  // Sets |value_| to the corresponding value from |client_hello_| if it exists.
+  virtual QuicErrorCode ProcessClientHello(
+      const CryptoHandshakeMessage& client_hello,
+      std::string* error_details) OVERRIDE;
+
+  // Sets |value_| to the corresponding value from |server_hello_| if it exists.
+  virtual QuicErrorCode ProcessServerHello(
+      const CryptoHandshakeMessage& server_hello,
+      std::string* error_details) OVERRIDE;
+
+ private:
+  uint32 value_;
+};
+
 // QuicConfig contains non-crypto configuration options that are negotiated in
 // the crypto handshake.
 class NET_EXPORT_PRIVATE QuicConfig {
@@ -171,6 +227,10 @@ class NET_EXPORT_PRIVATE QuicConfig {
 
   uint32 initial_round_trip_time_us() const;
 
+  void set_peer_initial_flow_control_window_bytes(uint32 window);
+
+  uint32 peer_initial_flow_control_window_bytes() const;
+
   bool negotiated();
 
   // SetDefaults sets the members to sensible, default values.
@@ -209,6 +269,8 @@ class NET_EXPORT_PRIVATE QuicConfig {
   QuicNegotiableUint32 server_initial_congestion_window_;
   // Initial round trip time estimate in microseconds.
   QuicNegotiableUint32 initial_round_trip_time_us_;
+  // Peer's initial flow control receive window in bytes.
+  QuicFixedUint32 peer_initial_flow_control_window_bytes_;
 };
 
 }  // namespace net