Add and persist a new field in AlternativeServiceInfo to list QUIC verisons advertised

net/http/http_server_properties.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.
 
 #ifndef NET_HTTP_HTTP_SERVER_PROPERTIES_H_
 #define NET_HTTP_HTTP_SERVER_PROPERTIES_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <ostream>
 #include <string>
 #include <tuple>
 #include <vector>
 
 #include "base/containers/mru_cache.h"
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "net/base/host_port_pair.h"
 #include "net/base/net_export.h"
 #include "net/quic/core/quic_bandwidth.h"
 #include "net/quic/core/quic_server_id.h"
+#include "net/quic/core/quic_versions.h"
 #include "net/socket/next_proto.h"
 #include "net/spdy/core/spdy_framer.h"  // TODO(willchan): Reconsider this.
 #include "net/spdy/core/spdy_protocol.h"
 #include "url/scheme_host_port.h"
 
 namespace base {
 class Value;
 }
 
 namespace net {
@@ skipping 76 matching lines @@
   std::string host;
   uint16_t port;
 };
 
 NET_EXPORT_PRIVATE std::ostream& operator<<(
     std::ostream& os,
     const AlternativeService& alternative_service);
 
 class NET_EXPORT_PRIVATE AlternativeServiceInfo {
  public:
+  static AlternativeServiceInfo CreateHttp2AlternativeServiceInfo(
+      const AlternativeService& alternative_service,
+      base::Time expiration);
+
+  static AlternativeServiceInfo CreateQuicAlternativeServiceInfo(
+      const AlternativeService& alternative_service,
+      base::Time expiration,
+      const QuicVersionVector& advertised_versions);
+
   AlternativeServiceInfo();
-
-  AlternativeServiceInfo(const AlternativeService& alternative_service,
-                         base::Time expiration);
-
-  AlternativeServiceInfo(NextProto protocol,
-                         const std::string& host,
-                         uint16_t port,
-                         base::Time expiration);
+  ~AlternativeServiceInfo();
 
   AlternativeServiceInfo(
       const AlternativeServiceInfo& alternative_service_info);
+
   AlternativeServiceInfo& operator=(
       const AlternativeServiceInfo& alternative_service_info);
 
   bool operator==(const AlternativeServiceInfo& other) const {
     return alternative_service_ == other.alternative_service() &&
-           expiration_ == other.expiration();
+           expiration_ == other.expiration() &&
+           advertised_versions_ == other.advertised_versions();
   }
 
   bool operator!=(const AlternativeServiceInfo& other) const {
     return !this->operator==(other);
   }
 
   std::string ToString() const;
 
   void set_alternative_service(const AlternativeService& alternative_service) {
     alternative_service_ = alternative_service;
   }
 
   void set_protocol(const NextProto& protocol) {
     alternative_service_.protocol = protocol;
   }
 
   void set_host(const std::string& host) { alternative_service_.host = host; }
 
   void set_port(uint16_t port) { alternative_service_.port = port; }
 
   void set_expiration(const base::Time& expiration) {
     expiration_ = expiration;
   }
 
+  void set_advertised_versions(const QuicVersionVector& advertised_versions) {
+    if (alternative_service_.protocol != kProtoQUIC)

[Bence, 2017/06/16 14:43:40]

DCHECK_EQ(kProtoQUIC, alternative_service.protocol);

[Zhongyi Shi, 2017/06/20 23:23:37]

Although we are expecting this method only be called when alt svc is using QUIC
protocol, there was no API enforcement on the protocol field. 

I think an early return after check will make sure that we are doing the right
thing regardless of the callsite correctness. DCHECK will only fire in a debug
build. Or should we change this to CHECK()?

[Bence, 2017/06/21 12:39:25]

Good points.

One option is to leave it as it is now, and I'm fine with that.

The other option is to make it part of the API (by adding a comment in the
header file), and use a DCHECK().  I have a slight preference to this, but early
return is also fine.

I do not think a CHECK() is necessary: it has the same runtime cost as an early
return, but my understanding is that a CHECK() is usually reserved for
preventing security issues/leaks.  Having a DCHECK() and adequate test coverage
should be enough to guarantee that all callers follow the API requirement.

+      return;
+
+    advertised_versions_ = advertised_versions;
+    std::sort(advertised_versions_.begin(), advertised_versions_.end());
+  }
+
   const AlternativeService& alternative_service() const {
     return alternative_service_;
   }
 
   base::Time expiration() const { return expiration_; }
 
+  const QuicVersionVector& advertised_versions() const {
+    return advertised_versions_;
+  }
+
  private:
+  AlternativeServiceInfo(const AlternativeService& alternative_service,
+                         base::Time expiration,
+                         const QuicVersionVector& advertised_versions);
+
   AlternativeService alternative_service_;
   base::Time expiration_;
+
+  // Lists all the QUIC versions that are advertised by the server and supported
+  // by Chrome. If empty, defaults to versions used by the current instance of
+  // the netstack.
+  // This list MUST be sorted in ascending order.
+  QuicVersionVector advertised_versions_;
 };
 
 struct NET_EXPORT SupportsQuic {
   SupportsQuic() : used_quic(false) {}
   SupportsQuic(bool used_quic, const std::string& address)
       : used_quic(used_quic),
         address(address) {}
 
   bool Equals(const SupportsQuic& other) const {
     return used_quic == other.used_quic && address == other.address;
@@ skipping 77 matching lines @@
 
   // Modify SSLConfig to force HTTP/1.1 if necessary.
   virtual void MaybeForceHTTP11(const HostPortPair& server,
                                 SSLConfig* ssl_config) = 0;
 
   // Return all alternative services for |origin|, including broken ones.
   // Returned alternative services never have empty hostnames.
   virtual AlternativeServiceInfoVector GetAlternativeServiceInfos(
       const url::SchemeHostPort& origin) = 0;
 
-  // Set a single alternative service for |origin|.  Previous alternative
+  // Set a single HTTP/2 alternative service for |origin|.  Previous
+  // alternative services for |origin| are discarded.
+  // |alternative_service.host| may be empty.
+  // Return true if |alternative_service_map_| has changed significantly enough
+  // that it should be persisted to disk.
+  virtual bool SetHttp2AlternativeService(
+      const url::SchemeHostPort& origin,
+      const AlternativeService& alternative_service,
+      base::Time expiration) = 0;
+
+  // Set a single QUIC alternative service for |origin|.  Previous alternative
   // services for |origin| are discarded.
   // |alternative_service.host| may be empty.
   // Return true if |alternative_service_map_| has changed significantly enough
   // that it should be persisted to disk.
-  virtual bool SetAlternativeService(
+  virtual bool SetQuicAlternativeService(
       const url::SchemeHostPort& origin,
       const AlternativeService& alternative_service,
-      base::Time expiration) = 0;
+      base::Time expiration,
+      const QuicVersionVector& advertised_versions) = 0;
 
   // Set alternative services for |origin|.  Previous alternative services for
   // |origin| are discarded.
   // Hostnames in |alternative_service_info_vector| may be empty.
   // |alternative_service_info_vector| may be empty.
   // Return true if |alternative_service_map_| has changed significantly enough
   // that it should be persisted to disk.
   virtual bool SetAlternativeServices(
       const url::SchemeHostPort& origin,
       const AlternativeServiceInfoVector& alternative_service_info_vector) = 0;
@@ skipping 72 matching lines @@
   // Returns whether HttpServerProperties is initialized.
   virtual bool IsInitialized() const = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(HttpServerProperties);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_SERVER_PROPERTIES_H_