src/servers/Server.h

   1 /*
   2  * Copyright (C) 1996-2021 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 33    Client-side Routines */
  10
  11 #ifndef SQUID_SERVERS_SERVER_H
  12 #define SQUID_SERVERS_SERVER_H
  13
  14 #include "anyp/forward.h"
  15 #include "anyp/ProtocolVersion.h"
  16 #include "base/AsyncJob.h"
  17 #include "BodyPipe.h"
  18 #include "comm/Write.h"
  19 #include "CommCalls.h"
  20 #include "log/forward.h"
  21 #include "Pipeline.h"
  22 #include "sbuf/SBuf.h"
  23 #include "servers/forward.h"
  24
  25 /**
  26  * Common base for all Server classes used
  27  * to manage connections from clients.
  28  */
  29 class Server : virtual public AsyncJob, public BodyProducer
  30 {
  31 public:
  32     Server(const MasterXactionPointer &xact);
  33     virtual ~Server() {}
  34
  35     /* AsyncJob API */
  36     virtual void start();
  37     virtual bool doneAll() const;
  38     virtual void swanSong();
  39
  40     /// whether to stop serving our client after reading EOF on its connection
  41     virtual bool shouldCloseOnEof() const = 0;
  42
  43     /// maybe grow the inBuf and schedule Comm::Read()
  44     void readSomeData();
  45
  46     /**
  47      * called when new request data has been read from the socket
  48      *
  49      * \retval false called comm_close or setReplyToError (the caller should bail)
  50      * \retval true  we did not call comm_close or setReplyToError
  51      */
  52     virtual bool handleReadData() = 0;
  53
  54     /// processing to be done after a Comm::Read()
  55     virtual void afterClientRead() = 0;
  56
  57     /// whether Comm::Read() is scheduled
  58     bool reading() const {return reader != NULL;}
  59
  60     /// cancels Comm::Read() if it is scheduled
  61     void stopReading();
  62
  63     /// Update flags and timeout after the first byte received
  64     virtual void receivedFirstByte() = 0;
  65
  66     /// maybe find some data to send and schedule a Comm::Write()
  67     virtual void writeSomeData() {}
  68
  69     /// schedule some data for a Comm::Write()
  70     void write(MemBuf *mb) {
  71         typedef CommCbMemFunT<Server, CommIoCbParams> Dialer;
  72         writer = JobCallback(33, 5, Dialer, this, Server::clientWriteDone);
  73         Comm::Write(clientConnection, mb, writer);
  74     }
  75
  76     /// schedule some data for a Comm::Write()
  77     void write(char *buf, int len) {
  78         typedef CommCbMemFunT<Server, CommIoCbParams> Dialer;
  79         writer = JobCallback(33, 5, Dialer, this, Server::clientWriteDone);
  80         Comm::Write(clientConnection, buf, len, writer, nullptr);
  81     }
  82
  83     /// processing to sync state after a Comm::Write()
  84     virtual void afterClientWrite(size_t) {}
  85
  86     /// whether Comm::Write() is scheduled
  87     bool writing() const {return writer != NULL;}
  88
  89 // XXX: should be 'protected:' for child access only,
  90 //      but all sorts of code likes to play directly
  91 //      with the I/O buffers and socket.
  92 public:
  93
  94     /// grows the available read buffer space (if possible)
  95     void maybeMakeSpaceAvailable();
  96
  97     // Client TCP connection details from comm layer.
  98     Comm::ConnectionPointer clientConnection;
  99
 100     /**
 101      * The transfer protocol currently being spoken on this connection.
 102      * HTTP/1.x CONNECT, HTTP/1.1 Upgrade and HTTP/2 SETTINGS offer the
 103      * ability to change protocols on the fly.
 104      */
 105     AnyP::ProtocolVersion transferProtocol;
 106
 107     /// Squid listening port details where this connection arrived.
 108     AnyP::PortCfgPointer port;
 109
 110     /// read I/O buffer for the client connection
 111     SBuf inBuf;
 112
 113     bool receivedFirstByte_; ///< true if at least one byte received on this connection
 114
 115     /// set of requests waiting to be serviced
 116     Pipeline pipeline;
 117
 118 protected:
 119     /// abort any pending transactions and prevent new ones (by closing)
 120     virtual void terminateAll(const Error &, const LogTagsErrors &) = 0;
 121
 122     void doClientRead(const CommIoCbParams &io);
 123     void clientWriteDone(const CommIoCbParams &io);
 124
 125     AsyncCall::Pointer reader; ///< set when we are reading
 126     AsyncCall::Pointer writer; ///< set when we are writing
 127 };
 128
 129 #endif /* SQUID_SERVERS_SERVER_H */
 130