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
181 * The constructor transparently initializes
182 * the socket engine which the ircd is using.
183 * Please note that if there is a catastrophic
184 * failure (for example, you try and enable
185 * epoll on a 2.4 linux kernel) then this
186 * function may bail back to the shell.
187 * @param Instance The creator/owner of this object
189 SocketEngine(InspIRCd* Instance);
192 * The destructor transparently tidies up
193 * any resources used by the socket engine.
195 virtual ~SocketEngine();
197 /** Add an EventHandler object to the engine.
198 * Use AddFd to add a file descriptor to the
199 * engine and have the socket engine monitor
200 * it. You must provide an object derived from
201 * EventHandler which implements HandleEvent()
202 * and optionally Readable() and Writeable().
203 * @param eh An event handling object to add
205 virtual bool AddFd(EventHandler* eh);
207 /** If you call this function and pass it an
208 * event handler, that event handler will
209 * receive the next available write event,
210 * even if the socket is a readable socket only.
211 * Developers should avoid constantly keeping
212 * an eventhandler in the writeable state,
213 * as this will consume large amounts of
215 * @param eh An event handler which wants to
216 * receive the next writeability event.
218 virtual void WantWrite(EventHandler* eh);
220 /** Returns the maximum number of file descriptors
221 * you may store in the socket engine at any one time.
222 * @return The maximum fd value
224 virtual int GetMaxFds();
226 /** Returns the number of file descriptor slots
227 * which are available for storing fds.
228 * @return The number of remaining fd's
230 virtual int GetRemainingFds();
232 /** Delete an event handler from the engine.
233 * This function call deletes an EventHandler
234 * from the engine, returning true if it succeeded
235 * and false if it failed. This does not free the
236 * EventHandler pointer using delete, if this is
237 * required you must do this yourself.
238 * Note on forcing deletes. DO NOT DO THIS! This is
239 * extremely dangerous and will most likely render the
240 * socketengine dead. This was added only for handling
241 * very rare cases where broken 3rd party libs destroys
242 * the OS socket beyond our control. If you can't explain
243 * in minute details why forcing is absolutely necessary
244 * then you don't need it. That was a NO!
245 * @param eh The event handler object to remove
246 * @param force *DANGEROUS* See method description!
247 * @return True if the event handler was removed
249 virtual bool DelFd(EventHandler* eh, bool force = false);
251 /** Returns true if a file descriptor exists in
252 * the socket engine's list.
253 * @param fd The event handler to look for
254 * @return True if this fd has an event handler
256 virtual bool HasFd(int fd);
258 /** Returns the EventHandler attached to a specific fd.
259 * If the fd isnt in the socketengine, returns NULL.
260 * @param fd The event handler to look for
261 * @return A pointer to the event handler, or NULL
263 virtual EventHandler* GetRef(int fd);
265 /** Waits for events and dispatches them to handlers.
266 * Please note that this doesnt wait long, only
267 * a couple of milliseconds. It returns the number of
268 * events which occured during this call.
269 * This method will dispatch events to their handlers
270 * by calling their EventHandler::HandleEvent()
271 * methods with the neccessary EventType value.
272 * @return The number of events which have occured.
274 virtual int DispatchEvents();
276 /** Returns the socket engines name.
277 * This returns the name of the engine for use
278 * in /VERSION responses.
279 * @return The socket engine name
281 virtual std::string GetName();
283 /** Returns true if the file descriptors in the
284 * given event handler are within sensible ranges
285 * which can be handled by the socket engine.
287 virtual bool BoundsCheckFd(EventHandler* eh);
289 /** Abstraction for BSD sockets accept(2).
290 * This function should emulate its namesake system call exactly.
291 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
292 * @return This method should return exactly the same values as the system call it emulates.
294 virtual int Accept(EventHandler* fd, sockaddr *addr, socklen_t *addrlen);
296 /** Abstraction for BSD sockets close(2).
297 * This function should emulate its namesake system call exactly.
298 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
299 * @return This method should return exactly the same values as the system call it emulates.
301 virtual int Close(EventHandler* fd);
303 /** Abstraction for BSD sockets close(2).
304 * This function should emulate its namesake system call exactly.
305 * This function should emulate its namesake system call exactly.
306 * @return This method should return exactly the same values as the system call it emulates.
308 virtual int Close(int fd);
310 /** Abstraction for BSD sockets send(2).
311 * This function should emulate its namesake system call exactly.
312 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
313 * @return This method should return exactly the same values as the system call it emulates.
315 virtual int Send(EventHandler* fd, const void *buf, size_t len, int flags);
317 /** Abstraction for BSD sockets recv(2).
318 * This function should emulate its namesake system call exactly.
319 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
320 * @return This method should return exactly the same values as the system call it emulates.
322 virtual int Recv(EventHandler* fd, void *buf, size_t len, int flags);
324 /** Abstraction for BSD sockets recvfrom(2).
325 * This function should emulate its namesake system call exactly.
326 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
327 * @return This method should return exactly the same values as the system call it emulates.
329 virtual int RecvFrom(EventHandler* fd, void *buf, size_t len, int flags, sockaddr *from, socklen_t *fromlen);
331 /** Abstraction for BSD sockets sendto(2).
332 * This function should emulate its namesake system call exactly.
333 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
334 * @return This method should return exactly the same values as the system call it emulates.
336 virtual int SendTo(EventHandler* fd, const void *buf, size_t len, int flags, const sockaddr *to, socklen_t tolen);
338 /** Abstraction for BSD sockets connect(2).
339 * This function should emulate its namesake system call exactly.
340 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
341 * @return This method should return exactly the same values as the system call it emulates.
343 virtual int Connect(EventHandler* fd, const sockaddr *serv_addr, socklen_t addrlen);
345 /** Make a file descriptor blocking.
346 * @param fd a file descriptor to set to blocking mode
347 * @return 0 on success, -1 on failure, errno is set appropriately.
349 virtual int Blocking(int fd);
351 /** Make a file descriptor nonblocking.
352 * @param fd A file descriptor to set to nonblocking mode
353 * @return 0 on success, -1 on failure, errno is set appropriately.
355 virtual int NonBlocking(int fd);
357 /** Abstraction for BSD sockets shutdown(2).
358 * This function should emulate its namesake system call exactly.
359 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
360 * @return This method should return exactly the same values as the system call it emulates.
362 virtual int Shutdown(EventHandler* fd, int how);
364 /** Abstraction for BSD sockets shutdown(2).
365 * This function should emulate its namesake system call exactly.
366 * @return This method should return exactly the same values as the system call it emulates.
368 virtual int Shutdown(int fd, int how);
370 /** Abstraction for BSD sockets bind(2).
371 * This function should emulate its namesake system call exactly.
372 * @return This method should return exactly the same values as the system call it emulates.
374 virtual int Bind(int fd, const sockaddr *my_addr, socklen_t addrlen);
376 /** Abstraction for BSD sockets listen(2).
377 * This function should emulate its namesake system call exactly.
378 * @return This method should return exactly the same values as the system call it emulates.
380 virtual int Listen(int sockfd, int backlog);
382 /** Abstraction for BSD sockets getsockname(2).
383 * This function should emulate its namesake system call exactly.
384 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
385 * @return This method should return exactly the same values as the system call it emulates.
387 virtual int GetSockName(EventHandler* fd, sockaddr *name, socklen_t* namelen);
389 /** This function is called immediately after fork().
390 * Some socket engines (notably kqueue) cannot have their
391 * handles inherited by forked processes. This method
392 * allows for the socket engine to re-create its handle
393 * after the daemon forks as the socket engine is created
394 * long BEFORE the daemon forks.
395 * @return void, but it is acceptable for this function to bail back to
396 * the shell or operating system on fatal error.
398 virtual void RecoverFromFork();