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.
43 /** This class is a basic I/O handler class.
44 * Any object which wishes to receive basic I/O events
45 * from the socketengine must derive from this class and
46 * implement the HandleEvent() method. The derived class
47 * must then be added to SocketEngine using the method
48 * SocketEngine::AddFd(), after which point the derived
49 * class will receive events to its HandleEvent() method.
50 * The derived class should also implement one of Readable()
51 * and Writeable(). In the current implementation, only
52 * Readable() is used. If this returns true, the socketengine
53 * inserts a readable socket. If it is false, the socketengine
54 * inserts a writeable socket. The derived class should never
55 * change the value this function returns without first
56 * deleting the socket from the socket engine. The only
57 * requirement beyond this for an event handler is that it
58 * must have a file descriptor. What this file descriptor
59 * is actually attached to is completely up to you.
61 class CoreExport EventHandler : public Extensible
65 * All events which can be handled
66 * must have a file descriptor.
67 * This allows you to add events for
68 * sockets, fifo's, pipes, and various
73 /** Pointer to the module which has hooked the given EventHandler for IO events.
78 /** Return the current hooker of IO events for this socket, or NULL.
79 * @return Hooker module, if set, or NULL.
83 /** Set a module as hooking IO events on this socket.
84 * @param IOHooker The module hooking IO
85 * @return True if the hook could be added, false otherwise.
87 bool AddIOHook(Module *IOHooker);
89 /** Remove IO hooking from a module
90 * @return True if hooking was successfully removed, false otherwise.
94 /** Get the current file descriptor
95 * @return The file descriptor of this handler
99 /** Set a new file desciptor
100 * @param FD The new file descriptor. Do not
101 * call this method without first deleting the
102 * object from the SocketEngine if you have
103 * added it to a SocketEngine instance.
113 virtual ~EventHandler() {}
115 /** Override this function to indicate readability.
116 * @return This should return true if the function
117 * wishes to receive EVENT_READ events. Do not change
118 * what this function returns while the event handler
119 * is still added to a SocketEngine instance!
120 * If this function is unimplemented, the base class
123 * NOTE: You cannot set both Readable() and
124 * Writeable() to true. If you wish to receive
125 * a write event for your object, you must call
126 * SocketEngine::WantWrite() instead. This will
127 * trigger your objects next EVENT_WRITE type event.
129 virtual bool Readable();
131 /** Override this function to indicate writeability.
132 * @return This should return true if the function
133 * wishes to receive EVENT_WRITE events. Do not change
134 * what this function returns while the event handler
135 * is still added to a SocketEngine instance!
136 * If this function is unimplemented, the base class
139 * NOTE: You cannot set both Readable() and
140 * Writeable() to true. If you wish to receive
141 * a write event for your object, you must call
142 * SocketEngine::WantWrite() instead. This will
143 * trigger your objects next EVENT_WRITE type event.
145 virtual bool Writeable();
147 /** Process an I/O event.
148 * You MUST implement this function in your derived
149 * class, and it will be called whenever read or write
150 * events are received, depending on what your functions
151 * Readable() and Writeable() returns and wether you
152 * previously made a call to SocketEngine::WantWrite().
153 * @param et either one of EVENT_READ for read events,
154 * and EVENT_WRITE for write events.
156 virtual void HandleEvent(EventType et, int errornum = 0) = 0;
159 /** Provides basic file-descriptor-based I/O support.
160 * The actual socketengine class presents the
161 * same interface on all operating systems, but
162 * its private members and internal behaviour
163 * should be treated as blackboxed, and vary
164 * from system to system and upon the config
165 * settings chosen by the server admin. The current
166 * version supports select, epoll and kqueue.
167 * The configure script will enable a socket engine
168 * based upon what OS is detected, and will derive
169 * a class from SocketEngine based upon what it finds.
170 * The derived classes file will also implement a
171 * classfactory, SocketEngineFactory, which will
172 * create a derived instance of SocketEngine using
173 * polymorphism so that the core and modules do not
174 * have to be aware of which SocketEngine derived
175 * class they are using.
177 class CoreExport SocketEngine : public Extensible
182 InspIRCd* ServerInstance;
183 /** Handle to socket engine, where needed.
186 /** Current number of descriptors in the engine
189 /** Reference table, contains all current handlers
199 void UpdateStats(size_t len_in, size_t len_out);
208 * The constructor transparently initializes
209 * the socket engine which the ircd is using.
210 * Please note that if there is a catastrophic
211 * failure (for example, you try and enable
212 * epoll on a 2.4 linux kernel) then this
213 * function may bail back to the shell.
214 * @param Instance The creator/owner of this object
216 SocketEngine(InspIRCd* Instance);
219 * The destructor transparently tidies up
220 * any resources used by the socket engine.
222 virtual ~SocketEngine();
224 /** Add an EventHandler object to the engine.
225 * Use AddFd to add a file descriptor to the
226 * engine and have the socket engine monitor
227 * it. You must provide an object derived from
228 * EventHandler which implements HandleEvent()
229 * and optionally Readable() and Writeable().
230 * @param eh An event handling object to add
232 virtual bool AddFd(EventHandler* eh);
234 /** If you call this function and pass it an
235 * event handler, that event handler will
236 * receive the next available write event,
237 * even if the socket is a readable socket only.
238 * Developers should avoid constantly keeping
239 * an eventhandler in the writeable state,
240 * as this will consume large amounts of
242 * @param eh An event handler which wants to
243 * receive the next writeability event.
245 virtual void WantWrite(EventHandler* eh);
247 /** Returns the maximum number of file descriptors
248 * you may store in the socket engine at any one time.
249 * @return The maximum fd value
251 virtual int GetMaxFds();
253 /** Returns the number of file descriptor slots
254 * which are available for storing fds.
255 * @return The number of remaining fd's
257 virtual int GetRemainingFds();
259 /** Delete an event handler from the engine.
260 * This function call deletes an EventHandler
261 * from the engine, returning true if it succeeded
262 * and false if it failed. This does not free the
263 * EventHandler pointer using delete, if this is
264 * required you must do this yourself.
265 * Note on forcing deletes. DO NOT DO THIS! This is
266 * extremely dangerous and will most likely render the
267 * socketengine dead. This was added only for handling
268 * very rare cases where broken 3rd party libs destroys
269 * the OS socket beyond our control. If you can't explain
270 * in minute details why forcing is absolutely necessary
271 * then you don't need it. That was a NO!
272 * @param eh The event handler object to remove
273 * @param force *DANGEROUS* See method description!
274 * @return True if the event handler was removed
276 virtual bool DelFd(EventHandler* eh, bool force = false);
278 /** Returns true if a file descriptor exists in
279 * the socket engine's list.
280 * @param fd The event handler to look for
281 * @return True if this fd has an event handler
283 virtual bool HasFd(int fd);
285 /** Returns the EventHandler attached to a specific fd.
286 * If the fd isnt in the socketengine, returns NULL.
287 * @param fd The event handler to look for
288 * @return A pointer to the event handler, or NULL
290 virtual EventHandler* GetRef(int fd);
292 /** Waits for events and dispatches them to handlers.
293 * Please note that this doesnt wait long, only
294 * a couple of milliseconds. It returns the number of
295 * events which occured during this call.
296 * This method will dispatch events to their handlers
297 * by calling their EventHandler::HandleEvent()
298 * methods with the neccessary EventType value.
299 * @return The number of events which have occured.
301 virtual int DispatchEvents();
303 /** Returns the socket engines name.
304 * This returns the name of the engine for use
305 * in /VERSION responses.
306 * @return The socket engine name
308 virtual std::string GetName();
310 /** Returns true if the file descriptors in the
311 * given event handler are within sensible ranges
312 * which can be handled by the socket engine.
314 virtual bool BoundsCheckFd(EventHandler* eh);
316 /** Abstraction for BSD sockets accept(2).
317 * This function should emulate its namesake system call exactly.
318 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
319 * @return This method should return exactly the same values as the system call it emulates.
321 virtual int Accept(EventHandler* fd, sockaddr *addr, socklen_t *addrlen);
323 /** Abstraction for BSD sockets close(2).
324 * This function should emulate its namesake system call exactly.
325 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
326 * @return This method should return exactly the same values as the system call it emulates.
328 virtual int Close(EventHandler* fd);
330 /** Abstraction for BSD sockets close(2).
331 * This function should emulate its namesake system call exactly.
332 * This function should emulate its namesake system call exactly.
333 * @return This method should return exactly the same values as the system call it emulates.
335 virtual int Close(int fd);
337 /** Abstraction for BSD sockets send(2).
338 * This function should emulate its namesake system call exactly.
339 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
340 * @return This method should return exactly the same values as the system call it emulates.
342 virtual int Send(EventHandler* fd, const void *buf, size_t len, int flags);
344 /** Abstraction for BSD sockets recv(2).
345 * This function should emulate its namesake system call exactly.
346 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
347 * @return This method should return exactly the same values as the system call it emulates.
349 virtual int Recv(EventHandler* fd, void *buf, size_t len, int flags);
351 /** Abstraction for BSD sockets recvfrom(2).
352 * This function should emulate its namesake system call exactly.
353 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
354 * @return This method should return exactly the same values as the system call it emulates.
356 virtual int RecvFrom(EventHandler* fd, void *buf, size_t len, int flags, sockaddr *from, socklen_t *fromlen);
358 /** Abstraction for BSD sockets sendto(2).
359 * This function should emulate its namesake system call exactly.
360 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
361 * @return This method should return exactly the same values as the system call it emulates.
363 virtual int SendTo(EventHandler* fd, const void *buf, size_t len, int flags, const sockaddr *to, socklen_t tolen);
365 /** Abstraction for BSD sockets connect(2).
366 * This function should emulate its namesake system call exactly.
367 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
368 * @return This method should return exactly the same values as the system call it emulates.
370 virtual int Connect(EventHandler* fd, const sockaddr *serv_addr, socklen_t addrlen);
372 /** Make a file descriptor blocking.
373 * @param fd a file descriptor to set to blocking mode
374 * @return 0 on success, -1 on failure, errno is set appropriately.
376 virtual int Blocking(int fd);
378 /** Make a file descriptor nonblocking.
379 * @param fd A file descriptor to set to nonblocking mode
380 * @return 0 on success, -1 on failure, errno is set appropriately.
382 virtual int NonBlocking(int fd);
384 /** Abstraction for BSD sockets shutdown(2).
385 * This function should emulate its namesake system call exactly.
386 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
387 * @return This method should return exactly the same values as the system call it emulates.
389 virtual int Shutdown(EventHandler* fd, int how);
391 /** Abstraction for BSD sockets shutdown(2).
392 * This function should emulate its namesake system call exactly.
393 * @return This method should return exactly the same values as the system call it emulates.
395 virtual int Shutdown(int fd, int how);
397 /** Abstraction for BSD sockets bind(2).
398 * This function should emulate its namesake system call exactly.
399 * @return This method should return exactly the same values as the system call it emulates.
401 virtual int Bind(int fd, const sockaddr *my_addr, socklen_t addrlen);
403 /** Abstraction for BSD sockets listen(2).
404 * This function should emulate its namesake system call exactly.
405 * @return This method should return exactly the same values as the system call it emulates.
407 virtual int Listen(int sockfd, int backlog);
409 /** Abstraction for BSD sockets getsockname(2).
410 * This function should emulate its namesake system call exactly.
411 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
412 * @return This method should return exactly the same values as the system call it emulates.
414 virtual int GetSockName(EventHandler* fd, sockaddr *name, socklen_t* namelen);
416 /** This function is called immediately after fork().
417 * Some socket engines (notably kqueue) cannot have their
418 * handles inherited by forked processes. This method
419 * allows for the socket engine to re-create its handle
420 * after the daemon forks as the socket engine is created
421 * long BEFORE the daemon forks.
422 * @return void, but it is acceptable for this function to bail back to
423 * the shell or operating system on fatal error.
425 virtual void RecoverFromFork();
427 /** Get data transfer statistics, kilobits per second in and out and total.
429 void GetStats(float &kbitpersec_in, float &kbitpersec_out, float &kbitpersec_total);