// 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_NETWORK_TRANSACTION_H_
#define NET_HTTP_HTTP_NETWORK_TRANSACTION_H_

#include <stdint.h>

#include <memory>
#include <string>

#include "base/gtest_prod_util.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/time/time.h"
#include "crypto/ec_private_key.h"
#include "net/base/net_error_details.h"
#include "net/base/net_export.h"
#include "net/base/network_throttle_manager.h"
#include "net/base/request_priority.h"
#include "net/http/http_auth.h"
#include "net/http/http_request_headers.h"
#include "net/http/http_response_info.h"
#include "net/http/http_stream_factory.h"
#include "net/http/http_transaction.h"
#include "net/log/net_log_with_source.h"
#include "net/proxy/proxy_service.h"
#include "net/socket/connection_attempts.h"
#include "net/ssl/channel_id_service.h"
#include "net/ssl/ssl_config_service.h"
#include "net/websockets/websocket_handshake_stream_base.h"

namespace crypto {
class ECPrivateKey;
}

namespace net {

class BidirectionalStreamImpl;
class HttpAuthController;
class HttpNetworkSession;
class HttpStream;
class HttpStreamRequest;
class IOBuffer;
class ProxyInfo;
class SSLPrivateKey;
struct HttpRequestInfo;

class NET_EXPORT_PRIVATE HttpNetworkTransaction
    : public HttpTransaction,
      public HttpStreamRequest::Delegate,
      public NetworkThrottleManager::ThrottleDelegate {
 public:
  HttpNetworkTransaction(RequestPriority priority,
                         HttpNetworkSession* session);

  ~HttpNetworkTransaction() override;

  // HttpTransaction methods:
  int Start(const HttpRequestInfo* request_info,
            const CompletionCallback& callback,
            const NetLogWithSource& net_log) override;
  int RestartIgnoringLastError(const CompletionCallback& callback) override;
  int RestartWithCertificate(scoped_refptr<X509Certificate> client_cert,
                             scoped_refptr<SSLPrivateKey> client_private_key,
                             const CompletionCallback& callback) override;
  int RestartWithAuth(const AuthCredentials& credentials,
                      const CompletionCallback& callback) override;
  bool IsReadyToRestartForAuth() override;

  int Read(IOBuffer* buf,
           int buf_len,
           const CompletionCallback& callback) override;
  void StopCaching() override;
  bool GetFullRequestHeaders(HttpRequestHeaders* headers) const override;
  int64_t GetTotalReceivedBytes() const override;
  int64_t GetTotalSentBytes() const override;
  void DoneReading() override;
  const HttpResponseInfo* GetResponseInfo() const override;
  LoadState GetLoadState() const override;
  void SetQuicServerInfo(QuicServerInfo* quic_server_info) override;
  bool GetLoadTimingInfo(LoadTimingInfo* load_timing_info) const override;
  bool GetRemoteEndpoint(IPEndPoint* endpoint) const override;
  void PopulateNetErrorDetails(NetErrorDetails* details) const override;
  void SetPriority(RequestPriority priority) override;
  void SetWebSocketHandshakeStreamCreateHelper(
      WebSocketHandshakeStreamBase::CreateHelper* create_helper) override;
  void SetBeforeNetworkStartCallback(
      const BeforeNetworkStartCallback& callback) override;
  void SetBeforeHeadersSentCallback(
      const BeforeHeadersSentCallback& callback) override;
  void SetRequestHeadersCallback(RequestHeadersCallback callback) override;
  void SetResponseHeadersCallback(ResponseHeadersCallback callback) override;

  int ResumeNetworkStart() override;

  // HttpStreamRequest::Delegate methods:
  void OnStreamReady(const SSLConfig& used_ssl_config,
                     const ProxyInfo& used_proxy_info,
                     std::unique_ptr<HttpStream> stream) override;
  void OnBidirectionalStreamImplReady(
      const SSLConfig& used_ssl_config,
      const ProxyInfo& used_proxy_info,
      std::unique_ptr<BidirectionalStreamImpl> stream) override;
  void OnWebSocketHandshakeStreamReady(
      const SSLConfig& used_ssl_config,
      const ProxyInfo& used_proxy_info,
      std::unique_ptr<WebSocketHandshakeStreamBase> stream) override;
  void OnStreamFailed(int status,
                      const NetErrorDetails& net_error_details,
                      const SSLConfig& used_ssl_config) override;
  void OnCertificateError(int status,
                          const SSLConfig& used_ssl_config,
                          const SSLInfo& ssl_info) override;
  void OnNeedsProxyAuth(const HttpResponseInfo& response_info,
                        const SSLConfig& used_ssl_config,
                        const ProxyInfo& used_proxy_info,
                        HttpAuthController* auth_controller) override;
  void OnNeedsClientAuth(const SSLConfig& used_ssl_config,
                         SSLCertRequestInfo* cert_info) override;
  void OnHttpsProxyTunnelResponse(const HttpResponseInfo& response_info,
                                  const SSLConfig& used_ssl_config,
                                  const ProxyInfo& used_proxy_info,
                                  std::unique_ptr<HttpStream> stream) override;

  void OnQuicBroken() override;
  void GetConnectionAttempts(ConnectionAttempts* out) const override;

  // NetworkThrottleManager::Delegate methods:
  void OnThrottleUnblocked(NetworkThrottleManager::Throttle* throttle) override;

 private:
  FRIEND_TEST_ALL_PREFIXES(HttpNetworkTransactionTest, ResetStateForRestart);
  FRIEND_TEST_ALL_PREFIXES(SpdyNetworkTransactionTest, WindowUpdateReceived);
  FRIEND_TEST_ALL_PREFIXES(SpdyNetworkTransactionTest, WindowUpdateSent);
  FRIEND_TEST_ALL_PREFIXES(SpdyNetworkTransactionTest, WindowUpdateOverflow);
  FRIEND_TEST_ALL_PREFIXES(SpdyNetworkTransactionTest, FlowControlStallResume);
  FRIEND_TEST_ALL_PREFIXES(SpdyNetworkTransactionTest,
                           FlowControlStallResumeAfterSettings);
  FRIEND_TEST_ALL_PREFIXES(SpdyNetworkTransactionTest,
                           FlowControlNegativeSendWindowSize);

  enum State {
    STATE_THROTTLE,
    STATE_THROTTLE_COMPLETE,
    STATE_NOTIFY_BEFORE_CREATE_STREAM,
    STATE_CREATE_STREAM,
    STATE_CREATE_STREAM_COMPLETE,
    STATE_INIT_STREAM,
    STATE_INIT_STREAM_COMPLETE,
    STATE_GENERATE_PROXY_AUTH_TOKEN,
    STATE_GENERATE_PROXY_AUTH_TOKEN_COMPLETE,
    STATE_GENERATE_SERVER_AUTH_TOKEN,
    STATE_GENERATE_SERVER_AUTH_TOKEN_COMPLETE,
    STATE_GET_PROVIDED_TOKEN_BINDING_KEY,
    STATE_GET_PROVIDED_TOKEN_BINDING_KEY_COMPLETE,
    STATE_GET_REFERRED_TOKEN_BINDING_KEY,
    STATE_GET_REFERRED_TOKEN_BINDING_KEY_COMPLETE,
    STATE_INIT_REQUEST_BODY,
    STATE_INIT_REQUEST_BODY_COMPLETE,
    STATE_BUILD_REQUEST,
    STATE_BUILD_REQUEST_COMPLETE,
    STATE_SEND_REQUEST,
    STATE_SEND_REQUEST_COMPLETE,
    STATE_READ_HEADERS,
    STATE_READ_HEADERS_COMPLETE,
    STATE_READ_BODY,
    STATE_READ_BODY_COMPLETE,
    STATE_DRAIN_BODY_FOR_AUTH_RESTART,
    STATE_DRAIN_BODY_FOR_AUTH_RESTART_COMPLETE,
    STATE_NONE
  };

  bool IsSecureRequest() const;
  bool IsTokenBindingEnabled() const;
  void RecordTokenBindingSupport() const;

  // Returns true if the request is using an HTTP(S) proxy without being
  // tunneled via the CONNECT method.
  bool UsingHttpProxyWithoutTunnel() const;

  void DoCallback(int result);
  void OnIOComplete(int result);

  // Runs the state transition loop.
  int DoLoop(int result);

  // Each of these methods corresponds to a State value.  Those with an input
  // argument receive the result from the previous state.  If a method returns
  // ERR_IO_PENDING, then the result from OnIOComplete will be passed to the
  // next state method as the result arg.
  int DoThrottle();
  int DoThrottleComplete();
  int DoNotifyBeforeCreateStream();
  int DoCreateStream();
  int DoCreateStreamComplete(int result);
  int DoInitStream();
  int DoInitStreamComplete(int result);
  int DoGenerateProxyAuthToken();
  int DoGenerateProxyAuthTokenComplete(int result);
  int DoGenerateServerAuthToken();
  int DoGenerateServerAuthTokenComplete(int result);
  int DoGetProvidedTokenBindingKey();
  int DoGetProvidedTokenBindingKeyComplete(int result);
  int DoGetReferredTokenBindingKey();
  int DoGetReferredTokenBindingKeyComplete(int result);
  int DoInitRequestBody();
  int DoInitRequestBodyComplete(int result);
  int DoBuildRequest();
  int DoBuildRequestComplete(int result);
  int DoSendRequest();
  int DoSendRequestComplete(int result);
  int DoReadHeaders();
  int DoReadHeadersComplete(int result);
  int DoReadBody();
  int DoReadBodyComplete(int result);
  int DoDrainBodyForAuthRestart();
  int DoDrainBodyForAuthRestartComplete(int result);

  int BuildRequestHeaders(bool using_http_proxy_without_tunnel);
  int BuildTokenBindingHeader(std::string* out);

  // Writes a log message to help debugging in the field when we block a proxy
  // response to a CONNECT request.
  void LogBlockedTunnelResponse(int response_code) const;

  // Called to handle a client certificate request.
  int HandleCertificateRequest(int error);

  // Called wherever ERR_HTTP_1_1_REQUIRED or
  // ERR_PROXY_HTTP_1_1_REQUIRED has to be handled.
  int HandleHttp11Required(int error);

  // Called to possibly handle a client authentication error.
  void HandleClientAuthError(int error);

  // Called to possibly recover from an SSL handshake error.  Sets next_state_
  // and returns OK if recovering from the error.  Otherwise, the same error
  // code is returned.
  int HandleSSLHandshakeError(int error);

  // Called to possibly recover from the given error.  Sets next_state_ and
  // returns OK if recovering from the error.  Otherwise, the same error code
  // is returned.
  int HandleIOError(int error);

  // Gets the response headers from the HttpStream.
  HttpResponseHeaders* GetResponseHeaders() const;

  // Called when the socket is unexpectedly closed.  Returns true if the request
  // should be resent in case of a socket reuse/close race.
  bool ShouldResendRequest() const;

  // Returns true if there have already been |kMaxRetryAttempts| retries for
  // HTTP2 or QUIC network errors, and no further retries should be attempted.
  bool HasExceededMaxRetries() const;

  // Resets the connection and the request headers for resend.  Called when
  // ShouldResendRequest() is true.
  void ResetConnectionAndRequestForResend();

  // Sets up the state machine to restart the transaction with auth.
  void PrepareForAuthRestart(HttpAuth::Target target);

  // Called when we don't need to drain the response body or have drained it.
  // Resets |connection_| unless |keep_alive| is true, then calls
  // ResetStateForRestart.  Sets |next_state_| appropriately.
  void DidDrainBodyForAuthRestart(bool keep_alive);

  // Resets the members of the transaction so it can be restarted.
  void ResetStateForRestart();

  // Resets the members of the transaction, except |stream_|, which needs
  // to be maintained for multi-round auth.
  void ResetStateForAuthRestart();

  // Caches network error details from the stream if available
  // and resets the stream.
  void CacheNetErrorDetailsAndResetStream();

  // Returns true if we should try to add a Proxy-Authorization header
  bool ShouldApplyProxyAuth() const;

  // Returns true if we should try to add an Authorization header.
  bool ShouldApplyServerAuth() const;

  // Handles HTTP status code 401 or 407.
  // HandleAuthChallenge() returns a network error code, or OK on success.
  // May update |pending_auth_target_| or |response_.auth_challenge|.
  int HandleAuthChallenge();

  // Returns true if we have auth credentials for the given target.
  bool HaveAuth(HttpAuth::Target target) const;

  // Get the {scheme, host, path, port} for the authentication target
  GURL AuthURL(HttpAuth::Target target) const;

  // Returns true if this transaction is for a WebSocket handshake
  bool ForWebSocketHandshake() const;

  void SetStream(HttpStream* stream);

  void CopyConnectionAttemptsFromStreamRequest();

  // Returns true if response "Content-Encoding" headers respect
  // "Accept-Encoding".
  bool ContentEncodingsValid() const;

  scoped_refptr<HttpAuthController>
      auth_controllers_[HttpAuth::AUTH_NUM_TARGETS];

  // Whether this transaction is waiting for proxy auth, server auth, or is
  // not waiting for any auth at all. |pending_auth_target_| is read and
  // cleared by RestartWithAuth().
  HttpAuth::Target pending_auth_target_;

  CompletionCallback io_callback_;
  CompletionCallback callback_;

  HttpNetworkSession* session_;

  NetLogWithSource net_log_;

  // Reset to null at the start of the Read state machine.
  const HttpRequestInfo* request_;

  // The requested URL.
  GURL url_;
  RequestPriority priority_;
  HttpResponseInfo response_;

  // |proxy_info_| is the ProxyInfo used by the HttpStreamRequest.
  ProxyInfo proxy_info_;

  std::unique_ptr<HttpStreamRequest> stream_request_;
  std::unique_ptr<HttpStream> stream_;

  // True if we've validated the headers that the stream parser has returned.
  bool headers_valid_;

  SSLConfig server_ssl_config_;
  SSLConfig proxy_ssl_config_;

  // Keys to use for signing message in Token Binding header.
  std::unique_ptr<crypto::ECPrivateKey> provided_token_binding_key_;
  std::unique_ptr<crypto::ECPrivateKey> referred_token_binding_key_;
  // Object to manage lookup of |provided_token_binding_key_| and
  // |referred_token_binding_key_|.
  ChannelIDService::Request token_binding_request_;

  HttpRequestHeaders request_headers_;

  // The size in bytes of the buffer we use to drain the response body that
  // we want to throw away.  The response body is typically a small error
  // page just a few hundred bytes long.
  static const int kDrainBodyBufferSize = 1024;

  // User buffer and length passed to the Read method.
  scoped_refptr<IOBuffer> read_buf_;
  int read_buf_len_;

  // Total number of bytes received on all destroyed HttpStreams for this
  // transaction.
  int64_t total_received_bytes_;

  // Total number of bytes sent on all destroyed HttpStreams for this
  // transaction.
  int64_t total_sent_bytes_;

  // When the transaction started / finished sending the request, including
  // the body, if present.
  base::TimeTicks send_start_time_;
  base::TimeTicks send_end_time_;

  // The next state in the state machine.
  State next_state_;

  // True when the tunnel is in the process of being established - we can't
  // read from the socket until the tunnel is done.
  bool establishing_tunnel_;

  // Enable pooling to a SpdySession with matching IP and certificate
  // even if the SpdySessionKey is different.
  bool enable_ip_based_pooling_;

  // Enable using alternative services for the request.
  bool enable_alternative_services_;

  // When a request is retried because of errors with the alternative service,
  // this will store the alternative service used.
  AlternativeService retried_alternative_service_;

  // The helper object to use to create WebSocketHandshakeStreamBase
  // objects. Only relevant when establishing a WebSocket connection.
  WebSocketHandshakeStreamBase::CreateHelper*
      websocket_handshake_stream_base_create_helper_;

  BeforeNetworkStartCallback before_network_start_callback_;
  BeforeHeadersSentCallback before_headers_sent_callback_;
  RequestHeadersCallback request_headers_callback_;
  ResponseHeadersCallback response_headers_callback_;

  ConnectionAttempts connection_attempts_;
  IPEndPoint remote_endpoint_;
  // Network error details for this transaction.
  NetErrorDetails net_error_details_;

  // Communicate lifetime of transaction to the throttler, and
  // throttled state to the transaction.
  std::unique_ptr<NetworkThrottleManager::Throttle> throttle_;

  // Number of retries made for network errors like ERR_SPDY_PING_FAILED,
  // ERR_SPDY_SERVER_REFUSED_STREAM, ERR_QUIC_HANDSHAKE_FAILED and
  // ERR_QUIC_PROTOCOL_ERROR. Currently we stop after 3 tries
  // (including the initial request) and fail the request.
  // This count excludes retries on reused sockets since a well
  // behaved server may time those out and thus the number
  // of times we can retry a request on reused sockets is limited.
  size_t retry_attempts_;

  DISALLOW_COPY_AND_ASSIGN(HttpNetworkTransaction);
};

}  // namespace net

#endif  // NET_HTTP_HTTP_NETWORK_TRANSACTION_H_