XrdProtocol.hh

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00001 #ifndef __XrdProtocol_H__
00002 #define __XrdProtocol_H__
00003 /******************************************************************************/
00004 /*                                                                            */
00005 /*                        X r d P r o t o c o l . h h                         */
00006 /*                                                                            */
00007 /* (c) 2004 by the Board of Trustees of the Leland Stanford, Jr., University  */
00008 /*   Produced by Andrew Hanushevsky for Stanford University under contract    */
00009 /*              DE-AC02-76-SFO0515 with the Department of Energy              */
00010 /*                                                                            */
00011 /* This file is part of the XRootD software suite.                            */
00012 /*                                                                            */
00013 /* XRootD is free software: you can redistribute it and/or modify it under    */
00014 /* the terms of the GNU Lesser General Public License as published by the     */
00015 /* Free Software Foundation, either version 3 of the License, or (at your     */
00016 /* option) any later version.                                                 */
00017 /*                                                                            */
00018 /* XRootD is distributed in the hope that it will be useful, but WITHOUT      */
00019 /* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or      */
00020 /* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public       */
00021 /* License for more details.                                                  */
00022 /*                                                                            */
00023 /* You should have received a copy of the GNU Lesser General Public License   */
00024 /* along with XRootD in a file called COPYING.LESSER (LGPL license) and file  */
00025 /* COPYING (GPL license).  If not, see <http://www.gnu.org/licenses/>.        */
00026 /*                                                                            */
00027 /* The copyright holder's institutional names and contributor's names may not */
00028 /* be used to endorse or promote products derived from this software without  */
00029 /* specific prior written permission of the institution or contributor.       */
00030 /******************************************************************************/
00031 
00032 #include "Xrd/XrdJob.hh"
00033  
00034 /******************************************************************************/
00035 /*                    X r d P r o t o c o l _ C o n f i g                     */
00036 /******************************************************************************/
00037   
00038 // The following class is passed to the XrdgetProtocol() and XrdgetProtocolPort()
00039 // functions to properly configure the protocol. This object is not stable and 
00040 // the protocol must copy out any values it desires to keep. It may copy the 
00041 // whole object using the supplied copy constructor.
00042 
00043 class XrdSysError;
00044 class XrdOucTrace;
00045 class XrdBuffManager;
00046 class XrdInet;
00047 class XrdScheduler;
00048 class XrdStats;
00049 
00050 struct sockaddr;
00051 
00052 class XrdProtocol_Config
00053 {
00054 public:
00055 
00056 // The following pointers may be copied; they are stable.
00057 //
00058 XrdSysError    *eDest;       // Stable -> Error Message/Logging Handler
00059 XrdInet        *NetTCP;      // Stable -> Network Object    (@ XrdgetProtocol)
00060 XrdBuffManager *BPool;       // Stable -> Buffer Pool Manager
00061 XrdScheduler   *Sched;       // Stable -> System Scheduler
00062 XrdStats       *Stats;       // Stable -> System Statistics (@ XrdgetProtocol)
00063 void           *Reserved;    // Stable -> Previously, the thread manager
00064 XrdOucTrace    *Trace;       // Stable -> Trace Information
00065 
00066 // The following information must be duplicated; it is unstable.
00067 //
00068 char            *ConfigFN;     // -> Configuration file
00069 int              Format;       // Binary format of this server
00070 int              Port;         // Port number
00071 int              WSize;        // Window size for Port
00072 const char      *AdmPath;      // Admin path
00073 int              AdmMode;      // Admin path mode
00074 const char      *myInst;       // Instance name
00075 const char      *myName;       // Host name
00076 const char      *myProg;       // Program name
00077 struct sockaddr *myAddr;       // Host address
00078 int              ConnMax;      // Max connections
00079 int              readWait;     // Max milliseconds to wait for data
00080 int              idleWait;     // Max milliseconds connection may be idle
00081 int              argc;         // Number of arguments
00082 char           **argv;         // Argument array (prescreened)
00083 char             DebugON;      // True if started with -d option
00084 int              WANPort;      // Port prefered for WAN connections (0 if none)
00085 int              WANWSize;     // Window size for the WANPort
00086 int              hailWait;     // Max milliseconds to wait for data after accept
00087 
00088                  XrdProtocol_Config(XrdProtocol_Config &rhs);
00089                  XrdProtocol_Config() {}
00090                 ~XrdProtocol_Config() {}
00091 };
00092 
00093 /******************************************************************************/
00094 /*                           X r d P r o t o c o l                            */
00095 /******************************************************************************/
00096 
00097 // This class is used by the Link object to process the input stream on a link.
00098 // At least one protocol object exists per Link object. Specific protocols are 
00099 // derived from this pure abstract class since a link can use one of several 
00100 // protocols. Indeed, startup and shutdown are handled by specialized protocols.
00101 
00102 // System configuration obtains an instance of a protocol by calling
00103 // XrdgetProtocol(), which must exist in the shared library.
00104 // This instance is used as the base pointer for Alloc(), Configure(), and
00105 // Match(). Unfortuantely, they cannot be static given the silly C++ rules.
00106 
00107 class XrdLink;
00108   
00109 class XrdProtocol : public XrdJob
00110 {
00111 public:
00112 
00113 // Match()     is invoked when a new link is created and we are trying
00114 //             to determine if this protocol can handle the link. It must
00115 //             return a protocol object if it can and NULL (0), otherwise.
00116 //
00117 virtual XrdProtocol  *Match(XrdLink *lp) = 0;
00118 
00119 // Process()   is invoked when a link has data waiting to be read
00120 //
00121 virtual int           Process(XrdLink *lp) = 0;
00122 
00123 // Recycle()   is invoked when this object is no longer needed. The method is
00124 //             passed the number of seconds the protocol was connected to the
00125 //             link and the reason for the disconnection, if any.
00126 //
00127 virtual void          Recycle(XrdLink *lp=0,int consec=0,const char *reason=0)=0;
00128 
00129 // Stats()     is invoked when we need statistics about all instances of the
00130 //             protocol. If a buffer is supplied, it must return a null 
00131 //             terminated string in the supplied buffer and the return value
00132 //             is the number of bytes placed in the buffer defined by C99 for 
00133 //             snprintf(). If no buffer is supplied, the method should return
00134 //             the maximum number of characters that could have been returned.
00135 //             Regardless of the buffer value, if do_sync is true, the method
00136 //             should include any local statistics in the global data (if any)
00137 //             prior to performing any action.
00138 //
00139 virtual int           Stats(char *buff, int blen, int do_sync=0) = 0;
00140 
00141             XrdProtocol(const char *jname): XrdJob(jname) {}
00142 virtual    ~XrdProtocol() {}
00143 };
00144 
00145 /******************************************************************************/
00146 /*                        X r d g e t P r o t o c o l                         */
00147 /******************************************************************************/
00148   
00149 /* This extern "C" function must be defined in the shared library plug-in
00150    implementing your protocol. It is called to obtain an instance of your
00151    protocol. This allows protocols to live outside of the protocol driver
00152    (i.e., to be loaded at run-time). The call is made after the call to
00153    XrdgetProtocolPort() to determine the port to be used (see below) which
00154    allows e network object (NetTCP) to be proerly defined and it's pointer
00155    is passed in the XrdProtocol_Config object for your use.
00156 
00157    Required return values:
00158    Success: Pointer to XrdProtocol object.
00159    Failure: Null pointer (i.e. 0) which causes the program to exit.
00160 
00161 extern "C"  // This is in a comment!
00162 {
00163        XrdProtocol *XrdgetProtocol(const char *protocol_name, char *parms,
00164                                    XrdProtocol_Config *pi) {....}
00165 }
00166 */
00167   
00168 /******************************************************************************/
00169 /*                    X r d g e t P r o t o c o l P o r t                     */
00170 /******************************************************************************/
00171   
00172 /* This extern "C" function must be defined for statically linked protocols
00173    but is optional for protocols defined as a shared library plug-in if the
00174    rules determining which port number to use is sufficient for your protocol.
00175    The function is called to obtain the actual port number to be used by the
00176    the protocol. The default port number is noted in XrdProtocol_Config Port.
00177    Initially, it has one of the fllowing values:
00178    <0 -> No port was specified.
00179    =0 -> An erbitrary port will be assigned.
00180    >0 -> This port number was specified.
00181 
00182    XrdgetProtoclPort() must return:
00183    <0 -> Failure is indicated and we terminate
00184    =0 -> Use an arbitrary port (even if this equals Port)
00185    >0 -> The returned port number must be used (even if it equals Port)
00186 
00187    When we finally call XrdgetProtocol(), the actual port number is indicated
00188    in Port and the network object is defined in NetTCP and bound to the port.
00189 
00190    Final Caveats: 1.  The network object (NetTCP) is not defined until
00191                       XrdgetProtocol() is called.
00192 
00193                   2.  The statistics object (Stats) is not defined until
00194                       XrdgetProtocol() is called.
00195 
00196                   3.  When the protocol is loaded from a shared library, you need
00197                       need not define XrdgetProtocolPort() if the standard port
00198                       determination scheme is sufficient.
00199 
00200 extern "C"  // This is in a comment!
00201 {
00202        int XrdgetProtocolPort(const char *protocol_name, char *parms,
00203                               XrdProtocol_Config *pi) {....}
00204 }
00205 */
00206 #endif

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