1 /* +------------------------------------+
2 * | Inspire Internet Relay Chat Daemon |
3 * +------------------------------------+
5 * InspIRCd: (C) 2002-2007 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
72 /** Get the current file descriptor
73 * @return The file descriptor of this handler
77 /** Set a new file desciptor
78 * @param FD The new file descriptor. Do not
79 * call this method without first deleting the
80 * object from the SocketEngine if you have
81 * added it to a SocketEngine instance.
91 virtual ~EventHandler() {}
93 /** Override this function to indicate readability.
94 * @return This should return true if the function
95 * wishes to receive EVENT_READ events. Do not change
96 * what this function returns while the event handler
97 * is still added to a SocketEngine instance!
98 * If this function is unimplemented, the base class
101 * NOTE: You cannot set both Readable() and
102 * Writeable() to true. If you wish to receive
103 * a write event for your object, you must call
104 * SocketEngine::WantWrite() instead. This will
105 * trigger your objects next EVENT_WRITE type event.
107 virtual bool Readable();
109 /** Override this function to indicate writeability.
110 * @return This should return true if the function
111 * wishes to receive EVENT_WRITE events. Do not change
112 * what this function returns while the event handler
113 * is still added to a SocketEngine instance!
114 * If this function is unimplemented, the base class
117 * NOTE: You cannot set both Readable() and
118 * Writeable() to true. If you wish to receive
119 * a write event for your object, you must call
120 * SocketEngine::WantWrite() instead. This will
121 * trigger your objects next EVENT_WRITE type event.
123 virtual bool Writeable();
125 /** Process an I/O event.
126 * You MUST implement this function in your derived
127 * class, and it will be called whenever read or write
128 * events are received, depending on what your functions
129 * Readable() and Writeable() returns and wether you
130 * previously made a call to SocketEngine::WantWrite().
131 * @param et either one of EVENT_READ for read events,
132 * and EVENT_WRITE for write events.
134 virtual void HandleEvent(EventType et, int errornum = 0) = 0;
137 /** Provides basic file-descriptor-based I/O support.
138 * The actual socketengine class presents the
139 * same interface on all operating systems, but
140 * its private members and internal behaviour
141 * should be treated as blackboxed, and vary
142 * from system to system and upon the config
143 * settings chosen by the server admin. The current
144 * version supports select, epoll and kqueue.
145 * The configure script will enable a socket engine
146 * based upon what OS is detected, and will derive
147 * a class from SocketEngine based upon what it finds.
148 * The derived classes file will also implement a
149 * classfactory, SocketEngineFactory, which will
150 * create a derived instance of SocketEngine using
151 * polymorphism so that the core and modules do not
152 * have to be aware of which SocketEngine derived
153 * class they are using.
155 class CoreExport SocketEngine : public Extensible
160 InspIRCd* ServerInstance;
161 /** Handle to socket engine, where needed.
164 /** Current number of descriptors in the engine
167 /** Reference table, contains all current handlers
169 EventHandler* ref[MAX_DESCRIPTORS];
173 * The constructor transparently initializes
174 * the socket engine which the ircd is using.
175 * Please note that if there is a catastrophic
176 * failure (for example, you try and enable
177 * epoll on a 2.4 linux kernel) then this
178 * function may bail back to the shell.
179 * @param Instance The creator/owner of this object
181 SocketEngine(InspIRCd* Instance);
184 * The destructor transparently tidies up
185 * any resources used by the socket engine.
187 virtual ~SocketEngine();
189 /** Add an EventHandler object to the engine.
190 * Use AddFd to add a file descriptor to the
191 * engine and have the socket engine monitor
192 * it. You must provide an object derived from
193 * EventHandler which implements HandleEvent()
194 * and optionally Readable() and Writeable().
195 * @param eh An event handling object to add
197 virtual bool AddFd(EventHandler* eh);
199 /** If you call this function and pass it an
200 * event handler, that event handler will
201 * receive the next available write event,
202 * even if the socket is a readable socket only.
203 * Developers should avoid constantly keeping
204 * an eventhandler in the writeable state,
205 * as this will consume large amounts of
207 * @param eh An event handler which wants to
208 * receive the next writeability event.
210 virtual void WantWrite(EventHandler* eh);
212 /** Returns the maximum number of file descriptors
213 * you may store in the socket engine at any one time.
214 * @return The maximum fd value
216 virtual int GetMaxFds();
218 /** Returns the number of file descriptor slots
219 * which are available for storing fds.
220 * @return The number of remaining fd's
222 virtual int GetRemainingFds();
224 /** Delete an event handler from the engine.
225 * This function call deletes an EventHandler
226 * from the engine, returning true if it succeeded
227 * and false if it failed. This does not free the
228 * EventHandler pointer using delete, if this is
229 * required you must do this yourself.
230 * Note on forcing deletes. DO NOT DO THIS! This is
231 * extremely dangerous and will most likely render the
232 * socketengine dead. This was added only for handling
233 * very rare cases where broken 3rd party libs destroys
234 * the OS socket beyond our control. If you can't explain
235 * in minute details why forcing is absolutely necessary
236 * then you don't need it. That was a NO!
237 * @param eh The event handler object to remove
238 * @param force *DANGEROUS* See method description!
239 * @return True if the event handler was removed
241 virtual bool DelFd(EventHandler* eh, bool force = false);
243 /** Returns true if a file descriptor exists in
244 * the socket engine's list.
245 * @param fd The event handler to look for
246 * @return True if this fd has an event handler
248 virtual bool HasFd(int fd);
250 /** Returns the EventHandler attached to a specific fd.
251 * If the fd isnt in the socketengine, returns NULL.
252 * @param fd The event handler to look for
253 * @return A pointer to the event handler, or NULL
255 virtual EventHandler* GetRef(int fd);
257 /** Waits for events and dispatches them to handlers.
258 * Please note that this doesnt wait long, only
259 * a couple of milliseconds. It returns the number of
260 * events which occured during this call.
261 * This method will dispatch events to their handlers
262 * by calling their EventHandler::HandleEvent()
263 * methods with the neccessary EventType value.
264 * @return The number of events which have occured.
266 virtual int DispatchEvents();
268 /** Returns the socket engines name.
269 * This returns the name of the engine for use
270 * in /VERSION responses.
271 * @return The socket engine name
273 virtual std::string GetName();
275 /** Returns true if the file descriptors in the
276 * given event handler are within sensible ranges
277 * which can be handled by the socket engine.
279 virtual bool BoundsCheckFd(EventHandler* eh);
281 /** Abstraction for BSD sockets accept(2).
282 * This function should emulate its namesake system call exactly.
283 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
284 * @return This method should return exactly the same values as the system call it emulates.
286 virtual int Accept(EventHandler* fd, sockaddr *addr, socklen_t *addrlen);
288 /** Abstraction for BSD sockets close(2).
289 * This function should emulate its namesake system call exactly.
290 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
291 * @return This method should return exactly the same values as the system call it emulates.
293 virtual int Close(EventHandler* fd);
295 /** Abstraction for BSD sockets close(2).
296 * This function should emulate its namesake system call exactly.
297 * This function should emulate its namesake system call exactly.
298 * @return This method should return exactly the same values as the system call it emulates.
300 virtual int Close(int fd);
302 /** Abstraction for BSD sockets send(2).
303 * This function should emulate its namesake system call exactly.
304 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
305 * @return This method should return exactly the same values as the system call it emulates.
307 virtual int Send(EventHandler* fd, const void *buf, size_t len, int flags);
309 /** Abstraction for BSD sockets recv(2).
310 * This function should emulate its namesake system call exactly.
311 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
312 * @return This method should return exactly the same values as the system call it emulates.
314 virtual int Recv(EventHandler* fd, void *buf, size_t len, int flags);
316 /** Abstraction for BSD sockets recvfrom(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 RecvFrom(EventHandler* fd, void *buf, size_t len, int flags, sockaddr *from, socklen_t *fromlen);
323 /** Abstraction for BSD sockets sendto(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 SendTo(EventHandler* fd, const void *buf, size_t len, int flags, const sockaddr *to, socklen_t tolen);
330 /** Abstraction for BSD sockets connect(2).
331 * This function should emulate its namesake system call exactly.
332 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
333 * @return This method should return exactly the same values as the system call it emulates.
335 virtual int Connect(EventHandler* fd, const sockaddr *serv_addr, socklen_t addrlen);
337 /** Make a file descriptor blocking.
338 * @param fd a file descriptor to set to blocking mode
339 * @return 0 on success, -1 on failure, errno is set appropriately.
341 virtual int Blocking(int fd);
343 /** Make a file descriptor nonblocking.
344 * @param fd A file descriptor to set to nonblocking mode
345 * @return 0 on success, -1 on failure, errno is set appropriately.
347 virtual int NonBlocking(int fd);
349 /** Abstraction for BSD sockets shutdown(2).
350 * This function should emulate its namesake system call exactly.
351 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
352 * @return This method should return exactly the same values as the system call it emulates.
354 virtual int Shutdown(EventHandler* fd, int how);
356 /** Abstraction for BSD sockets shutdown(2).
357 * This function should emulate its namesake system call exactly.
358 * @return This method should return exactly the same values as the system call it emulates.
360 virtual int Shutdown(int fd, int how);
362 /** Abstraction for BSD sockets bind(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 Bind(int fd, const sockaddr *my_addr, socklen_t addrlen);
368 /** Abstraction for BSD sockets listen(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 Listen(int sockfd, int backlog);
374 /** Abstraction for BSD sockets getsockname(2).
375 * This function should emulate its namesake system call exactly.
376 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
377 * @return This method should return exactly the same values as the system call it emulates.
379 virtual int GetSockName(EventHandler* fd, sockaddr *name, socklen_t* namelen);
381 /** This function is called immediately after fork().
382 * Some socket engines (notably kqueue) cannot have their
383 * handles inherited by forked processes. This method
384 * allows for the socket engine to re-create its handle
385 * after the daemon forks as the socket engine is created
386 * long BEFORE the daemon forks.
387 * @return void, but it is acceptable for this function to bail back to
388 * the shell or operating system on fatal error.
390 virtual void RecoverFromFork();