src/FwdState.h

   1 /*
   2  * Copyright (C) 1996-2020 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_FORWARD_H
  10 #define SQUID_FORWARD_H
  11
  12 #include "base/CbcPointer.h"
  13 #include "base/forward.h"
  14 #include "base/RefCount.h"
  15 #include "clients/forward.h"
  16 #include "comm.h"
  17 #include "comm/Connection.h"
  18 #include "comm/ConnOpener.h"
  19 #include "err_type.h"
  20 #include "fde.h"
  21 #include "http/StatusCode.h"
  22 #include "ip/Address.h"
  23 #include "PeerSelectState.h"
  24 #include "security/forward.h"
  25 #if USE_OPENSSL
  26 #include "ssl/support.h"
  27 #endif
  28
  29 /* forward decls */
  30
  31 class AccessLogEntry;
  32 typedef RefCount<AccessLogEntry> AccessLogEntryPointer;
  33 class ErrorState;
  34 class HttpRequest;
  35 class PconnPool;
  36 class ResolvedPeers;
  37 typedef RefCount<ResolvedPeers> ResolvedPeersPointer;
  38
  39 class HappyConnOpener;
  40 typedef CbcPointer<HappyConnOpener> HappyConnOpenerPointer;
  41 class HappyConnOpenerAnswer;
  42
  43 #if USE_OPENSSL
  44 namespace Ssl
  45 {
  46 class ErrorDetail;
  47 class CertValidationResponse;
  48 };
  49 #endif
  50
  51 /// Sets initial TOS value and Netfilter for the future outgoing connection.
  52 /// Updates the given Connection object, not the future transport connection.
  53 void GetMarkingsToServer(HttpRequest * request, Comm::Connection &conn);
  54
  55 /// Recomputes and applies TOS value and Netfilter to the outgoing connection.
  56 /// Updates both the given Connection object and the transport connection.
  57 void ResetMarkingsToServer(HttpRequest *, Comm::Connection &);
  58
  59 class HelperReply;
  60
  61 class FwdState: public RefCountable, public PeerSelectionInitiator
  62 {
  63     CBDATA_CHILD(FwdState);
  64
  65 public:
  66     typedef RefCount<FwdState> Pointer;
  67     virtual ~FwdState();
  68     static void initModule();
  69
  70     /// Initiates request forwarding to a peer or origin server.
  71     static void Start(const Comm::ConnectionPointer &client, StoreEntry *, HttpRequest *, const AccessLogEntryPointer &alp);
  72     /// Same as Start() but no master xaction info (AccessLogEntry) available.
  73     static void fwdStart(const Comm::ConnectionPointer &client, StoreEntry *, HttpRequest *);
  74     /// time left to finish the whole forwarding process (which started at fwdStart)
  75     static time_t ForwardTimeout(const time_t fwdStart);
  76     /// Whether there is still time to re-try after a previous connection failure.
  77     /// \param fwdStart The start time of the peer selection/connection process.
  78     static bool EnoughTimeToReForward(const time_t fwdStart);
  79
  80     /// This is the real beginning of server connection. Call it whenever
  81     /// the forwarding server destination has changed and a new one needs to be opened.
  82     /// Produces the cannot-forward error on fail if no better error exists.
  83     void useDestinations();
  84
  85     void fail(ErrorState *err);
  86     void unregister(Comm::ConnectionPointer &conn);
  87     void unregister(int fd);
  88     void complete();
  89     void handleUnregisteredServerEnd();
  90     int reforward();
  91     bool reforwardableStatus(const Http::StatusCode s) const;
  92     void serverClosed(int fd);
  93     void connectStart();
  94     void connectDone(const Comm::ConnectionPointer & conn, Comm::Flag status, int xerrno);
  95     bool checkRetry();
  96     bool checkRetriable();
  97     void dispatch();
  98
  99     void pconnPush(Comm::ConnectionPointer & conn, const char *domain);
 100
 101     bool dontRetry() { return flags.dont_retry; }
 102
 103     void dontRetry(bool val) { flags.dont_retry = val; }
 104
 105     /** return a ConnectionPointer to the current server connection (may or may not be open) */
 106     Comm::ConnectionPointer const & serverConnection() const { return serverConn; };
 107
 108 private:
 109     // hidden for safer management of self; use static fwdStart
 110     FwdState(const Comm::ConnectionPointer &client, StoreEntry *, HttpRequest *, const AccessLogEntryPointer &alp);
 111     void start(Pointer aSelf);
 112     void stopAndDestroy(const char *reason);
 113
 114     /* PeerSelectionInitiator API */
 115     virtual void noteDestination(Comm::ConnectionPointer conn) override;
 116     virtual void noteDestinationsEnd(ErrorState *selectionError) override;
 117
 118     void noteConnection(HappyConnOpenerAnswer &);
 119
 120 #if STRICT_ORIGINAL_DST
 121     void selectPeerForIntercepted();
 122 #endif
 123     static void logReplyStatus(int tries, const Http::StatusCode status);
 124     void doneWithRetries();
 125     void completed();
 126     void retryOrBail();
 127
 128     void usePinned();
 129
 130     /// whether a pinned to-peer connection can be replaced with another one
 131     /// (in order to retry or reforward a failed request)
 132     bool pinnedCanRetry() const;
 133
 134     ErrorState *makeConnectingError(const err_type type) const;
 135     void connectedToPeer(Security::EncryptorAnswer &answer);
 136     static void RegisterWithCacheManager(void);
 137
 138     void establishTunnelThruProxy();
 139     void tunnelEstablishmentDone(Http::TunnelerAnswer &answer);
 140     void secureConnectionToPeerIfNeeded();
 141     void successfullyConnectedToPeer();
 142
 143     /// stops monitoring server connection for closure and updates pconn stats
 144     void closeServerConnection(const char *reason);
 145
 146     void syncWithServerConn(const Comm::ConnectionPointer &server, const char *host, const bool reused);
 147     void syncHierNote(const Comm::ConnectionPointer &server, const char *host);
 148
 149     /// whether we have used up all permitted forwarding attempts
 150     bool exhaustedTries() const;
 151
 152     /// \returns the time left for this connection to become connected or 1 second if it is less than one second left
 153     time_t connectingTimeout(const Comm::ConnectionPointer &conn) const;
 154
 155     /// whether we are waiting for HappyConnOpener
 156     /// same as calls.connector but may differ from connOpener.valid()
 157     bool opening() const { return connOpener.set(); }
 158
 159     void cancelOpening(const char *reason);
 160
 161     void notifyConnOpener();
 162
 163 public:
 164     StoreEntry *entry;
 165     HttpRequest *request;
 166     AccessLogEntryPointer al; ///< info for the future access.log entry
 167
 168     static void abort(void*);
 169
 170 private:
 171     Pointer self;
 172     ErrorState *err;
 173     Comm::ConnectionPointer clientConn;        ///< a possibly open connection to the client.
 174     time_t start_t;
 175     int n_tries; ///< the number of forwarding attempts so far
 176
 177     // AsyncCalls which we set and may need cancelling.
 178     struct {
 179         AsyncCall::Pointer connector;  ///< a call linking us to the ConnOpener producing serverConn.
 180     } calls;
 181
 182     struct {
 183         bool connected_okay; ///< TCP link ever opened properly. This affects retry of POST,PUT,CONNECT,etc
 184         bool dont_retry;
 185         bool forward_completed;
 186         bool destinationsFound; ///< at least one candidate path found
 187     } flags;
 188
 189     HappyConnOpenerPointer connOpener; ///< current connection opening job
 190     ResolvedPeersPointer destinations; ///< paths for forwarding the request
 191     Comm::ConnectionPointer serverConn; ///< a successfully opened connection to a server.
 192
 193     AsyncCall::Pointer closeHandler; ///< The serverConn close handler
 194
 195     /// possible pconn race states
 196     typedef enum { raceImpossible, racePossible, raceHappened } PconnRace;
 197     PconnRace pconnRace; ///< current pconn race state
 198 };
 199
 200 void getOutgoingAddress(HttpRequest * request, Comm::ConnectionPointer conn);
 201
 202 /// a collection of previously used persistent Squid-to-peer HTTP(S) connections
 203 extern PconnPool *fwdPconnPool;
 204
 205 #endif /* SQUID_FORWARD_H */
 206