src/comm/ConnOpener.h

   1 /*
   2  * Copyright (C) 1996-2023 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 #ifndef _SQUID_SRC_COMM_OPENERSTATEDATA_H
  10 #define _SQUID_SRC_COMM_OPENERSTATEDATA_H
  11
  12 #include "base/AsyncCall.h"
  13 #include "base/AsyncJob.h"
  14 #include "cbdata.h"
  15 #include "comm/Flag.h"
  16 #include "comm/forward.h"
  17 #include "CommCalls.h"
  18
  19 namespace Comm
  20 {
  21
  22 /// Asynchronously opens a TCP connection. Returns CommConnectCbParams: either
  23 /// Comm::OK with an open connection or another Comm::Flag with a closed one.
  24 class ConnOpener : public AsyncJob
  25 {
  26     CBDATA_CHILD(ConnOpener);
  27
  28 public:
  29     typedef CbcPointer<ConnOpener> Pointer;
  30
  31     bool doneAll() const override;
  32
  33     ConnOpener(const Comm::ConnectionPointer &, const AsyncCall::Pointer &handler, time_t connect_timeout);
  34     ~ConnOpener() override;
  35
  36     void setHost(const char *);    ///< set the hostname note for this connection
  37     const char * getHost() const;  ///< get the hostname noted for this connection
  38
  39 protected:
  40     void start() override;
  41     void swanSong() override;
  42
  43 private:
  44     // Undefined because two openers cannot share a connection
  45     ConnOpener(const ConnOpener &);
  46     ConnOpener & operator =(const ConnOpener &c);
  47
  48     void earlyAbort(const CommCloseCbParams &);
  49     void timeout(const CommTimeoutCbParams &);
  50     void sendAnswer(Comm::Flag errFlag, int xerrno, const char *why);
  51     static void InProgressConnectRetry(int fd, void *data);
  52     static void DelayedConnectRetry(void *data);
  53     void doConnect();
  54     void connected();
  55     void lookupLocalAddress();
  56
  57     void retrySleep();
  58     void restart();
  59
  60     bool createFd();
  61     void closeFd();
  62     void keepFd();
  63     void cleanFd();
  64
  65     void cancelSleep();
  66
  67 private:
  68     char *host_;                         ///< domain name we are trying to connect to.
  69     int temporaryFd_;                    ///< the FD being opened. Do NOT set conn_->fd until it is fully open.
  70     Comm::ConnectionPointer conn_;       ///< single connection currently to be opened.
  71     AsyncCall::Pointer callback_;        ///< handler to be called on connection completion.
  72
  73     int totalTries_;   ///< total number of connection attempts over all destinations so far.
  74     int failRetries_;  ///< number of retries current destination has been tried.
  75
  76     /// if we are not done by then, we will call back with Comm::TIMEOUT
  77     time_t deadline_;
  78
  79     /// handles to calls which we may need to cancel.
  80     struct Calls {
  81         AsyncCall::Pointer earlyAbort_;
  82         AsyncCall::Pointer timeout_;
  83         /// Whether we are idling before retrying to connect; not yet a call
  84         /// [that we can cancel], but it will probably become one eventually.
  85         bool sleep_;
  86     } calls_;
  87 };
  88
  89 }; // namespace Comm
  90
  91 #endif /* _SQUID_SRC_COMM_CONNOPENER_H */
  92