-/* +------------------------------------+\r * | Inspire Internet Relay Chat Daemon |\r * +------------------------------------+\r *\r * InspIRCd: (C) 2002-2007 InspIRCd Development Team\r * See: http://www.inspircd.org/wiki/index.php/Credits\r *\r * This program is free but copyrighted software; see\r * the file COPYING for details.\r *\r * ---------------------------------------------------\r */\r\r#ifndef __SOCKETENGINE__\r#define __SOCKETENGINE__\r\r#include <vector>\r#include <string>\r#include <map>\r#include "inspircd_config.h"\r#include "base.h"\r\r/** Types of event an EventHandler may receive.\r * EVENT_READ is a readable file descriptor,\r * and EVENT_WRITE is a writeable file descriptor.\r * EVENT_ERROR can always occur, and indicates\r * a write error or read error on the socket,\r * e.g. EOF condition or broken pipe.\r */\renum EventType\r{\r /** Read event */\r EVENT_READ = 0,\r /** Write event */\r EVENT_WRITE = 1,\r /** Error event */\r EVENT_ERROR = 2\r};\r\rclass InspIRCd;\r\r/** This class is a basic I/O handler class.\r * Any object which wishes to receive basic I/O events\r * from the socketengine must derive from this class and\r * implement the HandleEvent() method. The derived class\r * must then be added to SocketEngine using the method\r * SocketEngine::AddFd(), after which point the derived\r * class will receive events to its HandleEvent() method.\r * The derived class should also implement one of Readable()\r * and Writeable(). In the current implementation, only\r * Readable() is used. If this returns true, the socketengine\r * inserts a readable socket. If it is false, the socketengine\r * inserts a writeable socket. The derived class should never\r * change the value this function returns without first\r * deleting the socket from the socket engine. The only\r * requirement beyond this for an event handler is that it\r * must have a file descriptor. What this file descriptor\r * is actually attached to is completely up to you.\r */\rclass CoreExport EventHandler : public Extensible\r{\r protected:\r /** File descriptor.\r * All events which can be handled\r * must have a file descriptor.\r * This allows you to add events for\r * sockets, fifo's, pipes, and various\r * other forms of IPC.\r */\r int fd;\r public:\r /** Get the current file descriptor\r * @return The file descriptor of this handler\r */\r int GetFd();\r\r /** Set a new file desciptor\r * @param FD The new file descriptor. Do not\r * call this method without first deleting the\r * object from the SocketEngine if you have\r * added it to a SocketEngine instance.\r */\r void SetFd(int FD);\r\r /** Constructor\r */\r EventHandler() {}\r\r /** Destructor\r */\r virtual ~EventHandler() {}\r\r /** Override this function to indicate readability.\r * @return This should return true if the function\r * wishes to receive EVENT_READ events. Do not change\r * what this function returns while the event handler\r * is still added to a SocketEngine instance!\r * If this function is unimplemented, the base class\r * will return true.\r *\r * NOTE: You cannot set both Readable() and\r * Writeable() to true. If you wish to receive\r * a write event for your object, you must call\r * SocketEngine::WantWrite() instead. This will\r * trigger your objects next EVENT_WRITE type event.\r */\r virtual bool Readable();\r\r /** Override this function to indicate writeability.\r * @return This should return true if the function\r * wishes to receive EVENT_WRITE events. Do not change\r * what this function returns while the event handler\r * is still added to a SocketEngine instance!\r * If this function is unimplemented, the base class\r * will return false.\r *\r * NOTE: You cannot set both Readable() and\r * Writeable() to true. If you wish to receive\r * a write event for your object, you must call\r * SocketEngine::WantWrite() instead. This will\r * trigger your objects next EVENT_WRITE type event.\r */\r virtual bool Writeable();\r\r /** Process an I/O event.\r * You MUST implement this function in your derived\r * class, and it will be called whenever read or write\r * events are received, depending on what your functions\r * Readable() and Writeable() returns and wether you\r * previously made a call to SocketEngine::WantWrite().\r * @param et either one of EVENT_READ for read events,\r * and EVENT_WRITE for write events.\r */\r virtual void HandleEvent(EventType et, int errornum = 0) = 0;\r\r#ifdef WINDOWS\r\r /** "Fake" file descriptor. This is windows-specific.\r */\r int m_internalFd;\r\r /** Pointer to read event. We delete this so the buffer can't be used\r * after the socket is deleted, and so it doesn't leak memory\r */\r void* m_readEvent;\r /** Pointer to a write event.\r */\r void* m_writeEvent;\r /** Pointer to an accept event.\r */\r void* m_acceptEvent;\r\r#endif\r};\r\r/** Provides basic file-descriptor-based I/O support.\r * The actual socketengine class presents the\r * same interface on all operating systems, but\r * its private members and internal behaviour\r * should be treated as blackboxed, and vary\r * from system to system and upon the config\r * settings chosen by the server admin. The current\r * version supports select, epoll and kqueue.\r * The configure script will enable a socket engine\r * based upon what OS is detected, and will derive\r * a class from SocketEngine based upon what it finds.\r * The derived classes file will also implement a\r * classfactory, SocketEngineFactory, which will\r * create a derived instance of SocketEngine using\r * polymorphism so that the core and modules do not\r * have to be aware of which SocketEngine derived\r * class they are using.\r */\rclass CoreExport SocketEngine : public Extensible\r{\rprotected:\r /** Owner/Creator\r */\r InspIRCd* ServerInstance;\r /** Handle to socket engine, where needed.\r */\r int EngineHandle;\r /** Current number of descriptors in the engine\r */\r int CurrentSetSize;\r /** Reference table, contains all current handlers\r */\r EventHandler* ref[MAX_DESCRIPTORS];\rpublic:\r\r /** Constructor.\r * The constructor transparently initializes\r * the socket engine which the ircd is using.\r * Please note that if there is a catastrophic\r * failure (for example, you try and enable\r * epoll on a 2.4 linux kernel) then this\r * function may bail back to the shell.\r * @param Instance The creator/owner of this object\r */\r SocketEngine(InspIRCd* Instance);\r\r /** Destructor.\r * The destructor transparently tidies up\r * any resources used by the socket engine.\r */\r virtual ~SocketEngine();\r\r /** Add an EventHandler object to the engine.\r * Use AddFd to add a file descriptor to the\r * engine and have the socket engine monitor\r * it. You must provide an object derived from\r * EventHandler which implements HandleEvent()\r * and optionally Readable() and Writeable().\r * @param eh An event handling object to add\r */\r virtual bool AddFd(EventHandler* eh);\r\r /** If you call this function and pass it an\r * event handler, that event handler will\r * receive the next available write event,\r * even if the socket is a readable socket only.\r * Developers should avoid constantly keeping\r * an eventhandler in the writeable state,\r * as this will consume large amounts of\r * CPU time.\r * @param eh An event handler which wants to\r * receive the next writeability event.\r */\r virtual void WantWrite(EventHandler* eh);\r\r /** Returns the maximum number of file descriptors\r * you may store in the socket engine at any one time.\r * @return The maximum fd value\r */\r virtual int GetMaxFds();\r\r /** Returns the number of file descriptor slots\r * which are available for storing fds.\r * @return The number of remaining fd's\r */\r virtual int GetRemainingFds();\r\r /** Delete an event handler from the engine.\r * This function call deletes an EventHandler\r * from the engine, returning true if it succeeded\r * and false if it failed. This does not free the\r * EventHandler pointer using delete, if this is\r * required you must do this yourself.\r * Note on forcing deletes. DO NOT DO THIS! This is\r * extremely dangerous and will most likely render the\r * socketengine dead. This was added only for handling\r * very rare cases where broken 3rd party libs destroys\r * the OS socket beyond our control. If you can't explain\r * in minute details why forcing is absolutely necessary\r * then you don't need it. That was a NO!\r * @param eh The event handler object to remove\r * @param force *DANGEROUS* See method description!\r * @return True if the event handler was removed\r */\r virtual bool DelFd(EventHandler* eh, bool force = false);\r\r /** Returns true if a file descriptor exists in\r * the socket engine's list.\r * @param fd The event handler to look for\r * @return True if this fd has an event handler\r */\r virtual bool HasFd(int fd);\r\r /** Returns the EventHandler attached to a specific fd.\r * If the fd isnt in the socketengine, returns NULL.\r * @param fd The event handler to look for\r * @return A pointer to the event handler, or NULL\r */\r virtual EventHandler* GetRef(int fd);\r\r /** Waits for events and dispatches them to handlers.\r * Please note that this doesnt wait long, only\r * a couple of milliseconds. It returns the number of\r * events which occured during this call.\r * This method will dispatch events to their handlers\r * by calling their EventHandler::HandleEvent()\r * methods with the neccessary EventType value.\r * @return The number of events which have occured.\r */\r virtual int DispatchEvents();\r\r /** Returns the socket engines name.\r * This returns the name of the engine for use\r * in /VERSION responses.\r * @return The socket engine name\r */\r virtual std::string GetName();\r};\r\r#endif\r\r
\ No newline at end of file
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ * Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
+ * Copyright (C) 2007-2008 Robin Burchell <robin+git@viroteck.net>
+ * Copyright (C) 2005-2007 Craig Edwards <craigedwards@brainbox.cc>
+ * Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
+ *
+ * This file is part of InspIRCd. InspIRCd is free software: you can
+ * redistribute it and/or modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#ifndef SOCKETENGINE_H
+#define SOCKETENGINE_H
+
+#include <vector>
+#include <string>
+#include <map>
+#include "inspircd_config.h"
+#include "socket.h"
+#include "base.h"
+
+/** Types of event an EventHandler may receive.
+ * EVENT_READ is a readable file descriptor,
+ * and EVENT_WRITE is a writeable file descriptor.
+ * EVENT_ERROR can always occur, and indicates
+ * a write error or read error on the socket,
+ * e.g. EOF condition or broken pipe.
+ */
+enum EventType
+{
+ /** Read event */
+ EVENT_READ = 0,
+ /** Write event */
+ EVENT_WRITE = 1,
+ /** Error event */
+ EVENT_ERROR = 2
+};
+
+/**
+ * Event mask for SocketEngine events
+ */
+enum EventMask
+{
+ /** Do not test this socket for readability
+ */
+ FD_WANT_NO_READ = 0x1,
+ /** Give a read event at all times when reads will not block.
+ */
+ FD_WANT_POLL_READ = 0x2,
+ /** Give a read event when there is new data to read.
+ *
+ * An event MUST be sent if there is new data to be read, and the most
+ * recent read/recv() on this FD returned EAGAIN. An event MAY be sent
+ * at any time there is data to be read on the socket.
+ */
+ FD_WANT_FAST_READ = 0x4,
+ /** Give an optional read event when reads begin to unblock
+ *
+ * This state is useful if you want to leave data in the OS receive
+ * queue but not get continuous event notifications about it, because
+ * it may not require a system call to transition from FD_WANT_FAST_READ
+ */
+ FD_WANT_EDGE_READ = 0x8,
+
+ /** Mask for all read events */
+ FD_WANT_READ_MASK = 0x0F,
+
+ /** Do not test this socket for writeability
+ */
+ FD_WANT_NO_WRITE = 0x10,
+ /** Give a write event at all times when writes will not block.
+ *
+ * You probably shouldn't use this state; if it's likely that the write
+ * will not block, try it first, then use FD_WANT_FAST_WRITE if it
+ * fails. If it's likely to block (or you are using polling-style reads)
+ * then use FD_WANT_SINGLE_WRITE.
+ */
+ FD_WANT_POLL_WRITE = 0x20,
+ /** Give a write event when writes don't block any more
+ *
+ * An event MUST be sent if writes will not block, and the most recent
+ * write/send() on this FD returned EAGAIN, or connect() returned
+ * EINPROGRESS. An event MAY be sent at any time that writes will not
+ * block.
+ *
+ * Before calling HandleEvent, a socket engine MAY change the state of
+ * the FD back to FD_WANT_EDGE_WRITE if it is simpler (for example, if a
+ * one-shot notification was registered). If further writes are needed,
+ * it is the responsibility of the event handler to change the state to
+ * one that will generate the required notifications
+ */
+ FD_WANT_FAST_WRITE = 0x40,
+ /** Give an optional write event on edge-triggered write unblock.
+ *
+ * This state is useful to avoid system calls when moving to/from
+ * FD_WANT_FAST_WRITE when writing data to a mostly-unblocked socket.
+ */
+ FD_WANT_EDGE_WRITE = 0x80,
+ /** Request a one-shot poll-style write notification. The socket will
+ * return to the FD_WANT_NO_WRITE state before HandleEvent is called.
+ */
+ FD_WANT_SINGLE_WRITE = 0x100,
+
+ /** Mask for all write events */
+ FD_WANT_WRITE_MASK = 0x1F0,
+
+ /** Add a trial read. During the next DispatchEvents invocation, this
+ * will call HandleEvent with EVENT_READ unless reads are known to be
+ * blocking.
+ */
+ FD_ADD_TRIAL_READ = 0x1000,
+ /** Assert that reads are known to block. This cancels FD_ADD_TRIAL_READ.
+ * Reset by SE before running EVENT_READ
+ */
+ FD_READ_WILL_BLOCK = 0x2000,
+
+ /** Add a trial write. During the next DispatchEvents invocation, this
+ * will call HandleEvent with EVENT_WRITE unless writes are known to be
+ * blocking.
+ *
+ * This could be used to group several writes together into a single
+ * send() syscall, or to ensure that writes are blocking when attempting
+ * to use FD_WANT_FAST_WRITE.
+ */
+ FD_ADD_TRIAL_WRITE = 0x4000,
+ /** Assert that writes are known to block. This cancels FD_ADD_TRIAL_WRITE.
+ * Reset by SE before running EVENT_WRITE
+ */
+ FD_WRITE_WILL_BLOCK = 0x8000,
+
+ /** Mask for trial read/trial write */
+ FD_TRIAL_NOTE_MASK = 0x5000
+};
+
+/** This class is a basic I/O handler class.
+ * Any object which wishes to receive basic I/O events
+ * from the socketengine must derive from this class and
+ * implement the HandleEvent() method. The derived class
+ * must then be added to SocketEngine using the method
+ * SocketEngine::AddFd(), after which point the derived
+ * class will receive events to its HandleEvent() method.
+ * The derived class should also implement one of Readable()
+ * and Writeable(). In the current implementation, only
+ * Readable() is used. If this returns true, the socketengine
+ * inserts a readable socket. If it is false, the socketengine
+ * inserts a writeable socket. The derived class should never
+ * change the value this function returns without first
+ * deleting the socket from the socket engine. The only
+ * requirement beyond this for an event handler is that it
+ * must have a file descriptor. What this file descriptor
+ * is actually attached to is completely up to you.
+ */
+class CoreExport EventHandler : public classbase
+{
+ private:
+ /** Private state maintained by socket engine */
+ int event_mask;
+ protected:
+ /** File descriptor.
+ * All events which can be handled must have a file descriptor. This
+ * allows you to add events for sockets, fifo's, pipes, and various
+ * other forms of IPC. Do not change this while the object is
+ * registered with the SocketEngine
+ */
+ int fd;
+ public:
+ /** Get the current file descriptor
+ * @return The file descriptor of this handler
+ */
+ inline int GetFd() const { return fd; }
+
+ inline int GetEventMask() const { return event_mask; }
+
+ /** Set a new file desciptor
+ * @param FD The new file descriptor. Do not call this method without
+ * first deleting the object from the SocketEngine if you have
+ * added it to a SocketEngine instance.
+ */
+ void SetFd(int FD);
+
+ /** Constructor
+ */
+ EventHandler();
+
+ /** Destructor
+ */
+ virtual ~EventHandler() {}
+
+ /** Process an I/O event.
+ * You MUST implement this function in your derived
+ * class, and it will be called whenever read or write
+ * events are received.
+ * @param et either one of EVENT_READ for read events,
+ * EVENT_WRITE for write events and EVENT_ERROR for
+ * error events.
+ * @param errornum The error code which goes with an EVENT_ERROR.
+ */
+ virtual void HandleEvent(EventType et, int errornum = 0) = 0;
+
+ friend class SocketEngine;
+};
+
+/** Provides basic file-descriptor-based I/O support.
+ * The actual socketengine class presents the
+ * same interface on all operating systems, but
+ * its private members and internal behaviour
+ * should be treated as blackboxed, and vary
+ * from system to system and upon the config
+ * settings chosen by the server admin. The current
+ * version supports select, epoll and kqueue.
+ * The configure script will enable a socket engine
+ * based upon what OS is detected, and will derive
+ * a class from SocketEngine based upon what it finds.
+ * The derived classes file will also implement a
+ * classfactory, SocketEngineFactory, which will
+ * create a derived instance of SocketEngine using
+ * polymorphism so that the core and modules do not
+ * have to be aware of which SocketEngine derived
+ * class they are using.
+ */
+class CoreExport SocketEngine
+{
+ protected:
+ /** Current number of descriptors in the engine
+ */
+ int CurrentSetSize;
+ /** Reference table, contains all current handlers
+ */
+ EventHandler** ref;
+ /** List of handlers that want a trial read/write
+ */
+ std::set<int> trials;
+
+ int MAX_DESCRIPTORS;
+
+ size_t indata;
+ size_t outdata;
+ time_t lastempty;
+
+ void UpdateStats(size_t len_in, size_t len_out);
+
+ virtual void OnSetEvent(EventHandler* eh, int old_mask, int new_mask) = 0;
+ void SetEventMask(EventHandler* eh, int value);
+public:
+
+ unsigned long TotalEvents;
+ unsigned long ReadEvents;
+ unsigned long WriteEvents;
+ unsigned long ErrorEvents;
+
+ /** Constructor.
+ * The constructor transparently initializes
+ * the socket engine which the ircd is using.
+ * Please note that if there is a catastrophic
+ * failure (for example, you try and enable
+ * epoll on a 2.4 linux kernel) then this
+ * function may bail back to the shell.
+ */
+ SocketEngine();
+
+ /** Destructor.
+ * The destructor transparently tidies up
+ * any resources used by the socket engine.
+ */
+ virtual ~SocketEngine();
+
+ /** Add an EventHandler object to the engine. Use AddFd to add a file
+ * descriptor to the engine and have the socket engine monitor it. You
+ * must provide an object derived from EventHandler which implements
+ * HandleEvent().
+ * @param eh An event handling object to add
+ * @param event_mask The initial event mask for the object
+ */
+ virtual bool AddFd(EventHandler* eh, int event_mask) = 0;
+
+ /** If you call this function and pass it an
+ * event handler, that event handler will
+ * receive the next available write event,
+ * even if the socket is a readable socket only.
+ * Developers should avoid constantly keeping
+ * an eventhandler in the writeable state,
+ * as this will consume large amounts of
+ * CPU time.
+ * @param eh The event handler to change
+ * @param event_mask The changes to make to the wait state
+ */
+ void ChangeEventMask(EventHandler* eh, int event_mask);
+
+ /** Returns the highest file descriptor you may store in the socket engine
+ * @return The maximum fd value
+ */
+ inline int GetMaxFds() const { return MAX_DESCRIPTORS; }
+
+ /** Returns the number of file descriptors being queried
+ * @return The set size
+ */
+ inline int GetUsedFds() const { return CurrentSetSize; }
+
+ /** Delete an event handler from the engine.
+ * This function call deletes an EventHandler
+ * from the engine, returning true if it succeeded
+ * and false if it failed. This does not free the
+ * EventHandler pointer using delete, if this is
+ * required you must do this yourself.
+ * @param eh The event handler object to remove
+ */
+ virtual void DelFd(EventHandler* eh) = 0;
+
+ /** Returns true if a file descriptor exists in
+ * the socket engine's list.
+ * @param fd The event handler to look for
+ * @return True if this fd has an event handler
+ */
+ virtual bool HasFd(int fd);
+
+ /** Returns the EventHandler attached to a specific fd.
+ * If the fd isnt in the socketengine, returns NULL.
+ * @param fd The event handler to look for
+ * @return A pointer to the event handler, or NULL
+ */
+ virtual EventHandler* GetRef(int fd);
+
+ /** Waits for events and dispatches them to handlers. Please note that
+ * this doesn't wait long, only a couple of milliseconds. It returns the
+ * number of events which occurred during this call. This method will
+ * dispatch events to their handlers by calling their
+ * EventHandler::HandleEvent() methods with the necessary EventType
+ * value.
+ * @return The number of events which have occured.
+ */
+ virtual int DispatchEvents() = 0;
+
+ /** Dispatch trial reads and writes. This causes the actual socket I/O
+ * to happen when writes have been pre-buffered.
+ */
+ virtual void DispatchTrialWrites();
+
+ /** Returns the socket engines name. This returns the name of the
+ * engine for use in /VERSION responses.
+ * @return The socket engine name
+ */
+ virtual std::string GetName() = 0;
+
+ /** Returns true if the file descriptors in the given event handler are
+ * within sensible ranges which can be handled by the socket engine.
+ */
+ virtual bool BoundsCheckFd(EventHandler* eh);
+
+ /** Abstraction for BSD sockets accept(2).
+ * This function should emulate its namesake system call exactly.
+ * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
+ * @param addr The client IP address and port
+ * @param addrlen The size of the sockaddr parameter.
+ * @return This method should return exactly the same values as the system call it emulates.
+ */
+ int Accept(EventHandler* fd, sockaddr *addr, socklen_t *addrlen);
+
+ /** Abstraction for BSD sockets close(2).
+ * This function should emulate its namesake system call exactly.
+ * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
+ * @return This method should return exactly the same values as the system call it emulates.
+ */
+ int Close(EventHandler* fd);
+
+ /** Abstraction for BSD sockets close(2).
+ * This function should emulate its namesake system call exactly.
+ * This function should emulate its namesake system call exactly.
+ * @return This method should return exactly the same values as the system call it emulates.
+ */
+ int Close(int fd);
+
+ /** Abstraction for BSD sockets send(2).
+ * This function should emulate its namesake system call exactly.
+ * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
+ * @param buf The buffer in which the data that is sent is stored.
+ * @param len The size of the buffer.
+ * @param flags A flag value that controls the sending of the data.
+ * @return This method should return exactly the same values as the system call it emulates.
+ */
+ int Send(EventHandler* fd, const void *buf, size_t len, int flags);
+
+ /** Abstraction for BSD sockets recv(2).
+ * This function should emulate its namesake system call exactly.
+ * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
+ * @param buf The buffer in which the data that is read is stored.
+ * @param len The size of the buffer.
+ * @param flags A flag value that controls the reception of the data.
+ * @return This method should return exactly the same values as the system call it emulates.
+ */
+ int Recv(EventHandler* fd, void *buf, size_t len, int flags);
+
+ /** Abstraction for BSD sockets recvfrom(2).
+ * This function should emulate its namesake system call exactly.
+ * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
+ * @param buf The buffer in which the data that is read is stored.
+ * @param len The size of the buffer.
+ * @param flags A flag value that controls the reception of the data.
+ * @param from The remote IP address and port.
+ * @param fromlen The size of the from parameter.
+ * @return This method should return exactly the same values as the system call it emulates.
+ */
+ int RecvFrom(EventHandler* fd, void *buf, size_t len, int flags, sockaddr *from, socklen_t *fromlen);
+
+ /** Abstraction for BSD sockets sendto(2).
+ * This function should emulate its namesake system call exactly.
+ * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
+ * @param buf The buffer in which the data that is sent is stored.
+ * @param len The size of the buffer.
+ * @param flags A flag value that controls the sending of the data.
+ * @param to The remote IP address and port.
+ * @param tolen The size of the to parameter.
+ * @return This method should return exactly the same values as the system call it emulates.
+ */
+ int SendTo(EventHandler* fd, const void *buf, size_t len, int flags, const sockaddr *to, socklen_t tolen);
+
+ /** Abstraction for BSD sockets connect(2).
+ * This function should emulate its namesake system call exactly.
+ * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
+ * @param serv_addr The server IP address and port.
+ * @param addrlen The size of the sockaddr parameter.
+ * @return This method should return exactly the same values as the system call it emulates.
+ */
+ int Connect(EventHandler* fd, const sockaddr *serv_addr, socklen_t addrlen);
+
+ /** Make a file descriptor blocking.
+ * @param fd a file descriptor to set to blocking mode
+ * @return 0 on success, -1 on failure, errno is set appropriately.
+ */
+ int Blocking(int fd);
+
+ /** Make a file descriptor nonblocking.
+ * @param fd A file descriptor to set to nonblocking mode
+ * @return 0 on success, -1 on failure, errno is set appropriately.
+ */
+ int NonBlocking(int fd);
+
+ /** Abstraction for BSD sockets shutdown(2).
+ * This function should emulate its namesake system call exactly.
+ * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
+ * @param how What part of the socket to shut down
+ * @return This method should return exactly the same values as the system call it emulates.
+ */
+ int Shutdown(EventHandler* fd, int how);
+
+ /** Abstraction for BSD sockets shutdown(2).
+ * This function should emulate its namesake system call exactly.
+ * @return This method should return exactly the same values as the system call it emulates.
+ */
+ int Shutdown(int fd, int how);
+
+ /** Abstraction for BSD sockets bind(2).
+ * This function should emulate its namesake system call exactly.
+ * @return This method should return exactly the same values as the system call it emulates.
+ */
+ int Bind(int fd, const irc::sockets::sockaddrs& addr);
+
+ /** Abstraction for BSD sockets listen(2).
+ * This function should emulate its namesake system call exactly.
+ * @return This method should return exactly the same values as the system call it emulates.
+ */
+ int Listen(int sockfd, int backlog);
+
+ /** Set SO_REUSEADDR and SO_LINGER on this file descriptor
+ */
+ void SetReuse(int sockfd);
+
+ /** This function is called immediately after fork().
+ * Some socket engines (notably kqueue) cannot have their
+ * handles inherited by forked processes. This method
+ * allows for the socket engine to re-create its handle
+ * after the daemon forks as the socket engine is created
+ * long BEFORE the daemon forks.
+ * @return void, but it is acceptable for this function to bail back to
+ * the shell or operating system on fatal error.
+ */
+ virtual void RecoverFromFork();
+
+ /** Get data transfer statistics, kilobits per second in and out and total.
+ */
+ void GetStats(float &kbitpersec_in, float &kbitpersec_out, float &kbitpersec_total);
+};
+
+SocketEngine* CreateSocketEngine();
+
+#endif
+