1 /* +------------------------------------+
2 * | Inspire Internet Relay Chat Daemon |
3 * +------------------------------------+
5 * InspIRCd: (C) 2002-2008 InspIRCd Development Team
6 * See: http://www.inspircd.org/wiki/index.php/Credits
8 * This program is free but copyrighted software; see
9 * the file COPYING for details.
11 * ---------------------------------------------------
14 #ifndef __SOCKETENGINE__
15 #define __SOCKETENGINE__
20 #include "inspircd_config.h"
23 /** Types of event an EventHandler may receive.
24 * EVENT_READ is a readable file descriptor,
25 * and EVENT_WRITE is a writeable file descriptor.
26 * EVENT_ERROR can always occur, and indicates
27 * a write error or read error on the socket,
28 * e.g. EOF condition or broken pipe.
42 /** This class is a basic I/O handler class.
43 * Any object which wishes to receive basic I/O events
44 * from the socketengine must derive from this class and
45 * implement the HandleEvent() method. The derived class
46 * must then be added to SocketEngine using the method
47 * SocketEngine::AddFd(), after which point the derived
48 * class will receive events to its HandleEvent() method.
49 * The derived class should also implement one of Readable()
50 * and Writeable(). In the current implementation, only
51 * Readable() is used. If this returns true, the socketengine
52 * inserts a readable socket. If it is false, the socketengine
53 * inserts a writeable socket. The derived class should never
54 * change the value this function returns without first
55 * deleting the socket from the socket engine. The only
56 * requirement beyond this for an event handler is that it
57 * must have a file descriptor. What this file descriptor
58 * is actually attached to is completely up to you.
60 class CoreExport EventHandler : public Extensible
64 * All events which can be handled
65 * must have a file descriptor.
66 * This allows you to add events for
67 * sockets, fifo's, pipes, and various
73 /** Get the current file descriptor
74 * @return The file descriptor of this handler
78 /** Set a new file desciptor
79 * @param FD The new file descriptor. Do not
80 * call this method without first deleting the
81 * object from the SocketEngine if you have
82 * added it to a SocketEngine instance.
92 virtual ~EventHandler() {}
94 /** Override this function to indicate readability.
95 * @return This should return true if the function
96 * wishes to receive EVENT_READ events. Do not change
97 * what this function returns while the event handler
98 * is still added to a SocketEngine instance!
99 * If this function is unimplemented, the base class
102 * NOTE: You cannot set both Readable() and
103 * Writeable() to true. If you wish to receive
104 * a write event for your object, you must call
105 * SocketEngine::WantWrite() instead. This will
106 * trigger your objects next EVENT_WRITE type event.
108 virtual bool Readable();
110 /** Override this function to indicate writeability.
111 * @return This should return true if the function
112 * wishes to receive EVENT_WRITE events. Do not change
113 * what this function returns while the event handler
114 * is still added to a SocketEngine instance!
115 * If this function is unimplemented, the base class
118 * NOTE: You cannot set both Readable() and
119 * Writeable() to true. If you wish to receive
120 * a write event for your object, you must call
121 * SocketEngine::WantWrite() instead. This will
122 * trigger your objects next EVENT_WRITE type event.
124 virtual bool Writeable();
126 /** Process an I/O event.
127 * You MUST implement this function in your derived
128 * class, and it will be called whenever read or write
129 * events are received, depending on what your functions
130 * Readable() and Writeable() returns and wether you
131 * previously made a call to SocketEngine::WantWrite().
132 * @param et either one of EVENT_READ for read events,
133 * and EVENT_WRITE for write events.
135 virtual void HandleEvent(EventType et, int errornum = 0) = 0;
138 /** Provides basic file-descriptor-based I/O support.
139 * The actual socketengine class presents the
140 * same interface on all operating systems, but
141 * its private members and internal behaviour
142 * should be treated as blackboxed, and vary
143 * from system to system and upon the config
144 * settings chosen by the server admin. The current
145 * version supports select, epoll and kqueue.
146 * The configure script will enable a socket engine
147 * based upon what OS is detected, and will derive
148 * a class from SocketEngine based upon what it finds.
149 * The derived classes file will also implement a
150 * classfactory, SocketEngineFactory, which will
151 * create a derived instance of SocketEngine using
152 * polymorphism so that the core and modules do not
153 * have to be aware of which SocketEngine derived
154 * class they are using.
156 class CoreExport SocketEngine : public Extensible
161 InspIRCd* ServerInstance;
162 /** Handle to socket engine, where needed.
165 /** Current number of descriptors in the engine
168 /** Reference table, contains all current handlers
170 EventHandler* ref[MAX_DESCRIPTORS];
179 * The constructor transparently initializes
180 * the socket engine which the ircd is using.
181 * Please note that if there is a catastrophic
182 * failure (for example, you try and enable
183 * epoll on a 2.4 linux kernel) then this
184 * function may bail back to the shell.
185 * @param Instance The creator/owner of this object
187 SocketEngine(InspIRCd* Instance);
190 * The destructor transparently tidies up
191 * any resources used by the socket engine.
193 virtual ~SocketEngine();
195 /** Add an EventHandler object to the engine.
196 * Use AddFd to add a file descriptor to the
197 * engine and have the socket engine monitor
198 * it. You must provide an object derived from
199 * EventHandler which implements HandleEvent()
200 * and optionally Readable() and Writeable().
201 * @param eh An event handling object to add
203 virtual bool AddFd(EventHandler* eh);
205 /** If you call this function and pass it an
206 * event handler, that event handler will
207 * receive the next available write event,
208 * even if the socket is a readable socket only.
209 * Developers should avoid constantly keeping
210 * an eventhandler in the writeable state,
211 * as this will consume large amounts of
213 * @param eh An event handler which wants to
214 * receive the next writeability event.
216 virtual void WantWrite(EventHandler* eh);
218 /** Returns the maximum number of file descriptors
219 * you may store in the socket engine at any one time.
220 * @return The maximum fd value
222 virtual int GetMaxFds();
224 /** Returns the number of file descriptor slots
225 * which are available for storing fds.
226 * @return The number of remaining fd's
228 virtual int GetRemainingFds();
230 /** Delete an event handler from the engine.
231 * This function call deletes an EventHandler
232 * from the engine, returning true if it succeeded
233 * and false if it failed. This does not free the
234 * EventHandler pointer using delete, if this is
235 * required you must do this yourself.
236 * Note on forcing deletes. DO NOT DO THIS! This is
237 * extremely dangerous and will most likely render the
238 * socketengine dead. This was added only for handling
239 * very rare cases where broken 3rd party libs destroys
240 * the OS socket beyond our control. If you can't explain
241 * in minute details why forcing is absolutely necessary
242 * then you don't need it. That was a NO!
243 * @param eh The event handler object to remove
244 * @param force *DANGEROUS* See method description!
245 * @return True if the event handler was removed
247 virtual bool DelFd(EventHandler* eh, bool force = false);
249 /** Returns true if a file descriptor exists in
250 * the socket engine's list.
251 * @param fd The event handler to look for
252 * @return True if this fd has an event handler
254 virtual bool HasFd(int fd);
256 /** Returns the EventHandler attached to a specific fd.
257 * If the fd isnt in the socketengine, returns NULL.
258 * @param fd The event handler to look for
259 * @return A pointer to the event handler, or NULL
261 virtual EventHandler* GetRef(int fd);
263 /** Waits for events and dispatches them to handlers.
264 * Please note that this doesnt wait long, only
265 * a couple of milliseconds. It returns the number of
266 * events which occured during this call.
267 * This method will dispatch events to their handlers
268 * by calling their EventHandler::HandleEvent()
269 * methods with the neccessary EventType value.
270 * @return The number of events which have occured.
272 virtual int DispatchEvents();
274 /** Returns the socket engines name.
275 * This returns the name of the engine for use
276 * in /VERSION responses.
277 * @return The socket engine name
279 virtual std::string GetName();
281 /** Returns true if the file descriptors in the
282 * given event handler are within sensible ranges
283 * which can be handled by the socket engine.
285 virtual bool BoundsCheckFd(EventHandler* eh);
287 /** Abstraction for BSD sockets accept(2).
288 * This function should emulate its namesake system call exactly.
289 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
290 * @return This method should return exactly the same values as the system call it emulates.
292 virtual int Accept(EventHandler* fd, sockaddr *addr, socklen_t *addrlen);
294 /** Abstraction for BSD sockets close(2).
295 * This function should emulate its namesake system call exactly.
296 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
297 * @return This method should return exactly the same values as the system call it emulates.
299 virtual int Close(EventHandler* fd);
301 /** Abstraction for BSD sockets close(2).
302 * This function should emulate its namesake system call exactly.
303 * This function should emulate its namesake system call exactly.
304 * @return This method should return exactly the same values as the system call it emulates.
306 virtual int Close(int fd);
308 /** Abstraction for BSD sockets send(2).
309 * This function should emulate its namesake system call exactly.
310 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
311 * @return This method should return exactly the same values as the system call it emulates.
313 virtual int Send(EventHandler* fd, const void *buf, size_t len, int flags);
315 /** Abstraction for BSD sockets recv(2).
316 * This function should emulate its namesake system call exactly.
317 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
318 * @return This method should return exactly the same values as the system call it emulates.
320 virtual int Recv(EventHandler* fd, void *buf, size_t len, int flags);
322 /** Abstraction for BSD sockets recvfrom(2).
323 * This function should emulate its namesake system call exactly.
324 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
325 * @return This method should return exactly the same values as the system call it emulates.
327 virtual int RecvFrom(EventHandler* fd, void *buf, size_t len, int flags, sockaddr *from, socklen_t *fromlen);
329 /** Abstraction for BSD sockets sendto(2).
330 * This function should emulate its namesake system call exactly.
331 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
332 * @return This method should return exactly the same values as the system call it emulates.
334 virtual int SendTo(EventHandler* fd, const void *buf, size_t len, int flags, const sockaddr *to, socklen_t tolen);
336 /** Abstraction for BSD sockets connect(2).
337 * This function should emulate its namesake system call exactly.
338 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
339 * @return This method should return exactly the same values as the system call it emulates.
341 virtual int Connect(EventHandler* fd, const sockaddr *serv_addr, socklen_t addrlen);
343 /** Make a file descriptor blocking.
344 * @param fd a file descriptor to set to blocking mode
345 * @return 0 on success, -1 on failure, errno is set appropriately.
347 virtual int Blocking(int fd);
349 /** Make a file descriptor nonblocking.
350 * @param fd A file descriptor to set to nonblocking mode
351 * @return 0 on success, -1 on failure, errno is set appropriately.
353 virtual int NonBlocking(int fd);
355 /** Abstraction for BSD sockets shutdown(2).
356 * This function should emulate its namesake system call exactly.
357 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
358 * @return This method should return exactly the same values as the system call it emulates.
360 virtual int Shutdown(EventHandler* fd, int how);
362 /** Abstraction for BSD sockets shutdown(2).
363 * This function should emulate its namesake system call exactly.
364 * @return This method should return exactly the same values as the system call it emulates.
366 virtual int Shutdown(int fd, int how);
368 /** Abstraction for BSD sockets bind(2).
369 * This function should emulate its namesake system call exactly.
370 * @return This method should return exactly the same values as the system call it emulates.
372 virtual int Bind(int fd, const sockaddr *my_addr, socklen_t addrlen);
374 /** Abstraction for BSD sockets listen(2).
375 * This function should emulate its namesake system call exactly.
376 * @return This method should return exactly the same values as the system call it emulates.
378 virtual int Listen(int sockfd, int backlog);
380 /** Abstraction for BSD sockets getsockname(2).
381 * This function should emulate its namesake system call exactly.
382 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
383 * @return This method should return exactly the same values as the system call it emulates.
385 virtual int GetSockName(EventHandler* fd, sockaddr *name, socklen_t* namelen);
387 /** This function is called immediately after fork().
388 * Some socket engines (notably kqueue) cannot have their
389 * handles inherited by forked processes. This method
390 * allows for the socket engine to re-create its handle
391 * after the daemon forks as the socket engine is created
392 * long BEFORE the daemon forks.
393 * @return void, but it is acceptable for this function to bail back to
394 * the shell or operating system on fatal error.
396 virtual void RecoverFromFork();