2 * InspIRCd -- Internet Relay Chat Daemon
4 * Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
5 * Copyright (C) 2007-2008 Robin Burchell <robin+git@viroteck.net>
6 * Copyright (C) 2005-2007 Craig Edwards <craigedwards@brainbox.cc>
7 * Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
9 * This file is part of InspIRCd. InspIRCd is free software: you can
10 * redistribute it and/or modify it under the terms of the GNU General Public
11 * License as published by the Free Software Foundation, version 2.
13 * This program is distributed in the hope that it will be useful, but WITHOUT
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
15 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
18 * You should have received a copy of the GNU General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
32 /** Types of event an EventHandler may receive.
33 * EVENT_READ is a readable file descriptor,
34 * and EVENT_WRITE is a writeable file descriptor.
35 * EVENT_ERROR can always occur, and indicates
36 * a write error or read error on the socket,
37 * e.g. EOF condition or broken pipe.
50 * Event mask for SocketEngine events
54 /** Do not test this socket for readability
56 FD_WANT_NO_READ = 0x1,
57 /** Give a read event at all times when reads will not block.
59 FD_WANT_POLL_READ = 0x2,
60 /** Give a read event when there is new data to read.
62 * An event MUST be sent if there is new data to be read, and the most
63 * recent read/recv() on this FD returned EAGAIN. An event MAY be sent
64 * at any time there is data to be read on the socket.
66 FD_WANT_FAST_READ = 0x4,
67 /** Give an optional read event when reads begin to unblock
69 * This state is useful if you want to leave data in the OS receive
70 * queue but not get continuous event notifications about it, because
71 * it may not require a system call to transition from FD_WANT_FAST_READ
73 FD_WANT_EDGE_READ = 0x8,
75 /** Mask for all read events */
76 FD_WANT_READ_MASK = 0x0F,
78 /** Do not test this socket for writeability
80 FD_WANT_NO_WRITE = 0x10,
81 /** Give a write event at all times when writes will not block.
83 * You probably shouldn't use this state; if it's likely that the write
84 * will not block, try it first, then use FD_WANT_FAST_WRITE if it
85 * fails. If it's likely to block (or you are using polling-style reads)
86 * then use FD_WANT_SINGLE_WRITE.
88 FD_WANT_POLL_WRITE = 0x20,
89 /** Give a write event when writes don't block any more
91 * An event MUST be sent if writes will not block, and the most recent
92 * write/send() on this FD returned EAGAIN, or connect() returned
93 * EINPROGRESS. An event MAY be sent at any time that writes will not
96 * Before calling HandleEvent, a socket engine MAY change the state of
97 * the FD back to FD_WANT_EDGE_WRITE if it is simpler (for example, if a
98 * one-shot notification was registered). If further writes are needed,
99 * it is the responsibility of the event handler to change the state to
100 * one that will generate the required notifications
102 FD_WANT_FAST_WRITE = 0x40,
103 /** Give an optional write event on edge-triggered write unblock.
105 * This state is useful to avoid system calls when moving to/from
106 * FD_WANT_FAST_WRITE when writing data to a mostly-unblocked socket.
108 FD_WANT_EDGE_WRITE = 0x80,
109 /** Request a one-shot poll-style write notification. The socket will
110 * return to the FD_WANT_NO_WRITE state before HandleEvent is called.
112 FD_WANT_SINGLE_WRITE = 0x100,
114 /** Mask for all write events */
115 FD_WANT_WRITE_MASK = 0x1F0,
117 /** Add a trial read. During the next DispatchEvents invocation, this
118 * will call HandleEvent with EVENT_READ unless reads are known to be
121 FD_ADD_TRIAL_READ = 0x1000,
122 /** Assert that reads are known to block. This cancels FD_ADD_TRIAL_READ.
123 * Reset by SE before running EVENT_READ
125 FD_READ_WILL_BLOCK = 0x2000,
127 /** Add a trial write. During the next DispatchEvents invocation, this
128 * will call HandleEvent with EVENT_WRITE unless writes are known to be
131 * This could be used to group several writes together into a single
132 * send() syscall, or to ensure that writes are blocking when attempting
133 * to use FD_WANT_FAST_WRITE.
135 FD_ADD_TRIAL_WRITE = 0x4000,
136 /** Assert that writes are known to block. This cancels FD_ADD_TRIAL_WRITE.
137 * Reset by SE before running EVENT_WRITE
139 FD_WRITE_WILL_BLOCK = 0x8000,
141 /** Mask for trial read/trial write */
142 FD_TRIAL_NOTE_MASK = 0x5000
145 /** This class is a basic I/O handler class.
146 * Any object which wishes to receive basic I/O events
147 * from the socketengine must derive from this class and
148 * implement the HandleEvent() method. The derived class
149 * must then be added to SocketEngine using the method
150 * SocketEngine::AddFd(), after which point the derived
151 * class will receive events to its HandleEvent() method.
152 * The derived class should also implement one of Readable()
153 * and Writeable(). In the current implementation, only
154 * Readable() is used. If this returns true, the socketengine
155 * inserts a readable socket. If it is false, the socketengine
156 * inserts a writeable socket. The derived class should never
157 * change the value this function returns without first
158 * deleting the socket from the socket engine. The only
159 * requirement beyond this for an event handler is that it
160 * must have a file descriptor. What this file descriptor
161 * is actually attached to is completely up to you.
163 class CoreExport EventHandler : public classbase
166 /** Private state maintained by socket engine */
170 * All events which can be handled must have a file descriptor. This
171 * allows you to add events for sockets, fifo's, pipes, and various
172 * other forms of IPC. Do not change this while the object is
173 * registered with the SocketEngine
177 /** Get the current file descriptor
178 * @return The file descriptor of this handler
180 inline int GetFd() const { return fd; }
182 inline int GetEventMask() const { return event_mask; }
184 /** Set a new file desciptor
185 * @param FD The new file descriptor. Do not call this method without
186 * first deleting the object from the SocketEngine if you have
187 * added it to a SocketEngine instance.
197 virtual ~EventHandler() {}
199 /** Process an I/O event.
200 * You MUST implement this function in your derived
201 * class, and it will be called whenever read or write
202 * events are received.
203 * @param et either one of EVENT_READ for read events,
204 * EVENT_WRITE for write events and EVENT_ERROR for
206 * @param errornum The error code which goes with an EVENT_ERROR.
208 virtual void HandleEvent(EventType et, int errornum = 0) = 0;
210 friend class SocketEngine;
213 /** Provides basic file-descriptor-based I/O support.
214 * The actual socketengine class presents the
215 * same interface on all operating systems, but
216 * its private members and internal behaviour
217 * should be treated as blackboxed, and vary
218 * from system to system and upon the config
219 * settings chosen by the server admin. The current
220 * version supports select, epoll and kqueue.
221 * The configure script will enable a socket engine
222 * based upon what OS is detected, and will derive
223 * a class from SocketEngine based upon what it finds.
224 * The derived classes file will also implement a
225 * classfactory, SocketEngineFactory, which will
226 * create a derived instance of SocketEngine using
227 * polymorphism so that the core and modules do not
228 * have to be aware of which SocketEngine derived
229 * class they are using.
231 class CoreExport SocketEngine
234 /** Current number of descriptors in the engine
237 /** Reference table, contains all current handlers
240 /** List of handlers that want a trial read/write
242 std::set<int> trials;
250 void UpdateStats(size_t len_in, size_t len_out);
252 virtual void OnSetEvent(EventHandler* eh, int old_mask, int new_mask) = 0;
253 void SetEventMask(EventHandler* eh, int value);
256 unsigned long TotalEvents;
257 unsigned long ReadEvents;
258 unsigned long WriteEvents;
259 unsigned long ErrorEvents;
262 * The constructor transparently initializes
263 * the socket engine which the ircd is using.
264 * Please note that if there is a catastrophic
265 * failure (for example, you try and enable
266 * epoll on a 2.4 linux kernel) then this
267 * function may bail back to the shell.
272 * The destructor transparently tidies up
273 * any resources used by the socket engine.
275 virtual ~SocketEngine();
277 /** Add an EventHandler object to the engine. Use AddFd to add a file
278 * descriptor to the engine and have the socket engine monitor it. You
279 * must provide an object derived from EventHandler which implements
281 * @param eh An event handling object to add
282 * @param event_mask The initial event mask for the object
284 virtual bool AddFd(EventHandler* eh, int event_mask) = 0;
286 /** If you call this function and pass it an
287 * event handler, that event handler will
288 * receive the next available write event,
289 * even if the socket is a readable socket only.
290 * Developers should avoid constantly keeping
291 * an eventhandler in the writeable state,
292 * as this will consume large amounts of
294 * @param eh The event handler to change
295 * @param event_mask The changes to make to the wait state
297 void ChangeEventMask(EventHandler* eh, int event_mask);
299 /** Returns the highest file descriptor you may store in the socket engine
300 * @return The maximum fd value
302 inline int GetMaxFds() const { return MAX_DESCRIPTORS; }
304 /** Returns the number of file descriptors being queried
305 * @return The set size
307 inline int GetUsedFds() const { return CurrentSetSize; }
309 /** Delete an event handler from the engine.
310 * This function call deletes an EventHandler
311 * from the engine, returning true if it succeeded
312 * and false if it failed. This does not free the
313 * EventHandler pointer using delete, if this is
314 * required you must do this yourself.
315 * @param eh The event handler object to remove
317 virtual void DelFd(EventHandler* eh) = 0;
319 /** Returns true if a file descriptor exists in
320 * the socket engine's list.
321 * @param fd The event handler to look for
322 * @return True if this fd has an event handler
324 virtual bool HasFd(int fd);
326 /** Returns the EventHandler attached to a specific fd.
327 * If the fd isnt in the socketengine, returns NULL.
328 * @param fd The event handler to look for
329 * @return A pointer to the event handler, or NULL
331 virtual EventHandler* GetRef(int fd);
333 /** Waits for events and dispatches them to handlers. Please note that
334 * this doesn't wait long, only a couple of milliseconds. It returns the
335 * number of events which occurred during this call. This method will
336 * dispatch events to their handlers by calling their
337 * EventHandler::HandleEvent() methods with the necessary EventType
339 * @return The number of events which have occured.
341 virtual int DispatchEvents() = 0;
343 /** Dispatch trial reads and writes. This causes the actual socket I/O
344 * to happen when writes have been pre-buffered.
346 virtual void DispatchTrialWrites();
348 /** Returns the socket engines name. This returns the name of the
349 * engine for use in /VERSION responses.
350 * @return The socket engine name
352 virtual std::string GetName() = 0;
354 /** Returns true if the file descriptors in the given event handler are
355 * within sensible ranges which can be handled by the socket engine.
357 virtual bool BoundsCheckFd(EventHandler* eh);
359 /** Abstraction for BSD sockets accept(2).
360 * This function should emulate its namesake system call exactly.
361 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
362 * @param addr The client IP address and port
363 * @param addrlen The size of the sockaddr parameter.
364 * @return This method should return exactly the same values as the system call it emulates.
366 int Accept(EventHandler* fd, sockaddr *addr, socklen_t *addrlen);
368 /** Abstraction for BSD sockets close(2).
369 * This function should emulate its namesake system call exactly.
370 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
371 * @return This method should return exactly the same values as the system call it emulates.
373 int Close(EventHandler* fd);
375 /** Abstraction for BSD sockets close(2).
376 * This function should emulate its namesake system call exactly.
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.
382 /** Abstraction for BSD sockets send(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 * @param buf The buffer in which the data that is sent is stored.
386 * @param len The size of the buffer.
387 * @param flags A flag value that controls the sending of the data.
388 * @return This method should return exactly the same values as the system call it emulates.
390 int Send(EventHandler* fd, const void *buf, size_t len, int flags);
392 /** Abstraction for BSD sockets recv(2).
393 * This function should emulate its namesake system call exactly.
394 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
395 * @param buf The buffer in which the data that is read is stored.
396 * @param len The size of the buffer.
397 * @param flags A flag value that controls the reception of the data.
398 * @return This method should return exactly the same values as the system call it emulates.
400 int Recv(EventHandler* fd, void *buf, size_t len, int flags);
402 /** Abstraction for BSD sockets recvfrom(2).
403 * This function should emulate its namesake system call exactly.
404 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
405 * @param buf The buffer in which the data that is read is stored.
406 * @param len The size of the buffer.
407 * @param flags A flag value that controls the reception of the data.
408 * @param from The remote IP address and port.
409 * @param fromlen The size of the from parameter.
410 * @return This method should return exactly the same values as the system call it emulates.
412 int RecvFrom(EventHandler* fd, void *buf, size_t len, int flags, sockaddr *from, socklen_t *fromlen);
414 /** Abstraction for BSD sockets sendto(2).
415 * This function should emulate its namesake system call exactly.
416 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
417 * @param buf The buffer in which the data that is sent is stored.
418 * @param len The size of the buffer.
419 * @param flags A flag value that controls the sending of the data.
420 * @param to The remote IP address and port.
421 * @param tolen The size of the to parameter.
422 * @return This method should return exactly the same values as the system call it emulates.
424 int SendTo(EventHandler* fd, const void *buf, size_t len, int flags, const sockaddr *to, socklen_t tolen);
426 /** Abstraction for BSD sockets connect(2).
427 * This function should emulate its namesake system call exactly.
428 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
429 * @param serv_addr The server IP address and port.
430 * @param addrlen The size of the sockaddr parameter.
431 * @return This method should return exactly the same values as the system call it emulates.
433 int Connect(EventHandler* fd, const sockaddr *serv_addr, socklen_t addrlen);
435 /** Make a file descriptor blocking.
436 * @param fd a file descriptor to set to blocking mode
437 * @return 0 on success, -1 on failure, errno is set appropriately.
439 int Blocking(int fd);
441 /** Make a file descriptor nonblocking.
442 * @param fd A file descriptor to set to nonblocking mode
443 * @return 0 on success, -1 on failure, errno is set appropriately.
445 int NonBlocking(int fd);
447 /** Abstraction for BSD sockets shutdown(2).
448 * This function should emulate its namesake system call exactly.
449 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
450 * @param how What part of the socket to shut down
451 * @return This method should return exactly the same values as the system call it emulates.
453 int Shutdown(EventHandler* fd, int how);
455 /** Abstraction for BSD sockets shutdown(2).
456 * This function should emulate its namesake system call exactly.
457 * @return This method should return exactly the same values as the system call it emulates.
459 int Shutdown(int fd, int how);
461 /** Abstraction for BSD sockets bind(2).
462 * This function should emulate its namesake system call exactly.
463 * @return This method should return exactly the same values as the system call it emulates.
465 int Bind(int fd, const irc::sockets::sockaddrs& addr);
467 /** Abstraction for BSD sockets listen(2).
468 * This function should emulate its namesake system call exactly.
469 * @return This method should return exactly the same values as the system call it emulates.
471 int Listen(int sockfd, int backlog);
473 /** Set SO_REUSEADDR and SO_LINGER on this file descriptor
475 void SetReuse(int sockfd);
477 /** This function is called immediately after fork().
478 * Some socket engines (notably kqueue) cannot have their
479 * handles inherited by forked processes. This method
480 * allows for the socket engine to re-create its handle
481 * after the daemon forks as the socket engine is created
482 * long BEFORE the daemon forks.
483 * @return void, but it is acceptable for this function to bail back to
484 * the shell or operating system on fatal error.
486 virtual void RecoverFromFork();
488 /** Get data transfer statistics, kilobits per second in and out and total.
490 void GetStats(float &kbitpersec_in, float &kbitpersec_out, float &kbitpersec_total);
493 SocketEngine* CreateSocketEngine();