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/>.
41 * Event mask for SocketEngine events
45 /** Do not test this socket for readability
47 FD_WANT_NO_READ = 0x1,
48 /** Give a read event at all times when reads will not block.
50 FD_WANT_POLL_READ = 0x2,
51 /** Give a read event when there is new data to read.
53 * An event MUST be sent if there is new data to be read, and the most
54 * recent read/recv() on this FD returned EAGAIN. An event MAY be sent
55 * at any time there is data to be read on the socket.
57 FD_WANT_FAST_READ = 0x4,
58 /** Give an optional read event when reads begin to unblock
60 * This state is useful if you want to leave data in the OS receive
61 * queue but not get continuous event notifications about it, because
62 * it may not require a system call to transition from FD_WANT_FAST_READ
64 FD_WANT_EDGE_READ = 0x8,
66 /** Mask for all read events */
67 FD_WANT_READ_MASK = 0x0F,
69 /** Do not test this socket for writeability
71 FD_WANT_NO_WRITE = 0x10,
72 /** Give a write event at all times when writes will not block.
74 * You probably shouldn't use this state; if it's likely that the write
75 * will not block, try it first, then use FD_WANT_FAST_WRITE if it
76 * fails. If it's likely to block (or you are using polling-style reads)
77 * then use FD_WANT_SINGLE_WRITE.
79 FD_WANT_POLL_WRITE = 0x20,
80 /** Give a write event when writes don't block any more
82 * An event MUST be sent if writes will not block, and the most recent
83 * write/send() on this FD returned EAGAIN, or connect() returned
84 * EINPROGRESS. An event MAY be sent at any time that writes will not
87 * Before calling HandleEvent, a socket engine MAY change the state of
88 * the FD back to FD_WANT_EDGE_WRITE if it is simpler (for example, if a
89 * one-shot notification was registered). If further writes are needed,
90 * it is the responsibility of the event handler to change the state to
91 * one that will generate the required notifications
93 FD_WANT_FAST_WRITE = 0x40,
94 /** Give an optional write event on edge-triggered write unblock.
96 * This state is useful to avoid system calls when moving to/from
97 * FD_WANT_FAST_WRITE when writing data to a mostly-unblocked socket.
99 FD_WANT_EDGE_WRITE = 0x80,
100 /** Request a one-shot poll-style write notification. The socket will
101 * return to the FD_WANT_NO_WRITE state before HandleEvent is called.
103 FD_WANT_SINGLE_WRITE = 0x100,
105 /** Mask for all write events */
106 FD_WANT_WRITE_MASK = 0x1F0,
108 /** Add a trial read. During the next DispatchEvents invocation, this
109 * will call HandleEvent with EVENT_READ unless reads are known to be
112 FD_ADD_TRIAL_READ = 0x1000,
113 /** Assert that reads are known to block. This cancels FD_ADD_TRIAL_READ.
114 * Reset by SE before running EVENT_READ
116 FD_READ_WILL_BLOCK = 0x2000,
118 /** Add a trial write. During the next DispatchEvents invocation, this
119 * will call HandleEvent with EVENT_WRITE unless writes are known to be
122 * This could be used to group several writes together into a single
123 * send() syscall, or to ensure that writes are blocking when attempting
124 * to use FD_WANT_FAST_WRITE.
126 FD_ADD_TRIAL_WRITE = 0x4000,
127 /** Assert that writes are known to block. This cancels FD_ADD_TRIAL_WRITE.
128 * Reset by SE before running EVENT_WRITE
130 FD_WRITE_WILL_BLOCK = 0x8000,
132 /** Mask for trial read/trial write */
133 FD_TRIAL_NOTE_MASK = 0x5000
136 /** This class is a basic I/O handler class.
137 * Any object which wishes to receive basic I/O events
138 * from the socketengine must derive from this class and
139 * implement the HandleEvent() method. The derived class
140 * must then be added to SocketEngine using the method
141 * SocketEngine::AddFd(), after which point the derived
142 * class will receive events to its HandleEvent() method.
143 * The derived class should also implement one of Readable()
144 * and Writeable(). In the current implementation, only
145 * Readable() is used. If this returns true, the socketengine
146 * inserts a readable socket. If it is false, the socketengine
147 * inserts a writeable socket. The derived class should never
148 * change the value this function returns without first
149 * deleting the socket from the socket engine. The only
150 * requirement beyond this for an event handler is that it
151 * must have a file descriptor. What this file descriptor
152 * is actually attached to is completely up to you.
154 class CoreExport EventHandler : public classbase
157 /** Private state maintained by socket engine */
160 void SetEventMask(int mask) { event_mask = mask; }
164 * All events which can be handled must have a file descriptor. This
165 * allows you to add events for sockets, fifo's, pipes, and various
166 * other forms of IPC. Do not change this while the object is
167 * registered with the SocketEngine
171 /** Get the current file descriptor
172 * @return The file descriptor of this handler
174 inline int GetFd() const { return fd; }
176 inline int GetEventMask() const { return event_mask; }
178 /** Set a new file desciptor
179 * @param FD The new file descriptor. Do not call this method without
180 * first deleting the object from the SocketEngine if you have
181 * added it to a SocketEngine instance.
191 virtual ~EventHandler() {}
193 /** Called by the socket engine in case of a read event
195 virtual void OnEventHandlerRead() = 0;
197 /** Called by the socket engine in case of a write event.
198 * The default implementation does nothing.
200 virtual void OnEventHandlerWrite();
202 /** Called by the socket engine in case of an error event.
203 * The default implementation does nothing.
204 * @param errornum Error code
206 virtual void OnEventHandlerError(int errornum);
208 friend class SocketEngine;
211 /** Provides basic file-descriptor-based I/O support.
212 * The actual socketengine class presents the
213 * same interface on all operating systems, but
214 * its private members and internal behaviour
215 * should be treated as blackboxed, and vary
216 * from system to system and upon the config
217 * settings chosen by the server admin. The current
218 * version supports select, epoll and kqueue.
219 * The configure script will enable a socket engine
220 * based upon what OS is detected, and will derive
221 * a class from SocketEngine based upon what it finds.
222 * The derived classes file will also implement a
223 * classfactory, SocketEngineFactory, which will
224 * create a derived instance of SocketEngine using
225 * polymorphism so that the core and modules do not
226 * have to be aware of which SocketEngine derived
227 * class they are using.
229 class CoreExport SocketEngine
232 /** Socket engine statistics: count of various events, bandwidth usage
236 mutable size_t indata;
237 mutable size_t outdata;
238 mutable time_t lastempty;
240 /** Reset the byte counters and lastempty if there wasn't a reset in this second.
242 void CheckFlush() const;
245 /** Constructor, initializes member vars except indata and outdata because those are set to 0
246 * in CheckFlush() the first time Update() or GetBandwidth() is called.
248 Statistics() : lastempty(0), TotalEvents(0), ReadEvents(0), WriteEvents(0), ErrorEvents(0) { }
250 /** Increase the counters for bytes sent/received in this second.
251 * @param len_in Bytes received, 0 if updating number of bytes written.
252 * @param len_out Bytes sent, 0 if updating number of bytes read.
254 void Update(size_t len_in, size_t len_out);
256 /** Get data transfer statistics.
257 * @param kbitspersec_in Filled with incoming traffic in this second in kbit/s.
258 * @param kbitspersec_out Filled with outgoing traffic in this second in kbit/s.
259 * @param kbitspersec_total Filled with total traffic in this second in kbit/s.
261 void CoreExport GetBandwidth(float& kbitpersec_in, float& kbitpersec_out, float& kbitpersec_total) const;
263 unsigned long TotalEvents;
264 unsigned long ReadEvents;
265 unsigned long WriteEvents;
266 unsigned long ErrorEvents;
270 /** Reference table, contains all current handlers
272 static std::vector<EventHandler*> ref;
275 /** Current number of descriptors in the engine
277 static size_t CurrentSetSize;
278 /** List of handlers that want a trial read/write
280 static std::set<int> trials;
282 static int MAX_DESCRIPTORS;
284 /** Socket engine statistics: count of various events, bandwidth usage
286 static Statistics stats;
288 static void OnSetEvent(EventHandler* eh, int old_mask, int new_mask);
290 /** Add an event handler to the base socket engine. AddFd(EventHandler*, int) should call this.
292 static bool AddFdRef(EventHandler* eh);
294 static void DelFdRef(EventHandler* eh);
296 template <typename T>
297 static void ResizeDouble(std::vector<T>& vect)
299 if (SocketEngine::CurrentSetSize > vect.size())
300 vect.resize(vect.size() * 2);
305 typedef iovec IOVector;
307 typedef WindowsIOVec IOVector;
311 * The constructor transparently initializes
312 * the socket engine which the ircd is using.
313 * Please note that if there is a catastrophic
314 * failure (for example, you try and enable
315 * epoll on a 2.4 linux kernel) then this
316 * function may bail back to the shell.
317 * @return void, but it is acceptable for this function to bail back to
318 * the shell or operating system on fatal error.
323 * The destructor transparently tidies up
324 * any resources used by the socket engine.
326 static void Deinit();
328 /** Add an EventHandler object to the engine. Use AddFd to add a file
329 * descriptor to the engine and have the socket engine monitor it. You
330 * must provide an object derived from EventHandler which implements
332 * @param eh An event handling object to add
333 * @param event_mask The initial event mask for the object
335 static bool AddFd(EventHandler* eh, int event_mask);
337 /** If you call this function and pass it an
338 * event handler, that event handler will
339 * receive the next available write event,
340 * even if the socket is a readable socket only.
341 * Developers should avoid constantly keeping
342 * an eventhandler in the writeable state,
343 * as this will consume large amounts of
345 * @param eh The event handler to change
346 * @param event_mask The changes to make to the wait state
348 static void ChangeEventMask(EventHandler* eh, int event_mask);
350 /** Returns the number of file descriptors reported by the system this program may use
351 * when it was started.
352 * @return If positive, the number of file descriptors that the system reported that we
353 * may use. Otherwise (<= 0) this number could not be determined.
355 static int GetMaxFds() { return MAX_DESCRIPTORS; }
357 /** Returns the number of file descriptors being queried
358 * @return The set size
360 static size_t GetUsedFds() { return CurrentSetSize; }
362 /** Delete an event handler from the engine.
363 * This function call deletes an EventHandler
364 * from the engine, returning true if it succeeded
365 * and false if it failed. This does not free the
366 * EventHandler pointer using delete, if this is
367 * required you must do this yourself.
368 * @param eh The event handler object to remove
370 static void DelFd(EventHandler* eh);
372 /** Returns true if a file descriptor exists in
373 * the socket engine's list.
374 * @param fd The event handler to look for
375 * @return True if this fd has an event handler
377 static bool HasFd(int fd);
379 /** Returns the EventHandler attached to a specific fd.
380 * If the fd isnt in the socketengine, returns NULL.
381 * @param fd The event handler to look for
382 * @return A pointer to the event handler, or NULL
384 static EventHandler* GetRef(int fd);
386 /** Waits for events and dispatches them to handlers. Please note that
387 * this doesn't wait long, only a couple of milliseconds. It returns the
388 * number of events which occurred during this call. This method will
389 * dispatch events to their handlers by calling their
390 * EventHandler::HandleEvent() methods with the necessary EventType
392 * @return The number of events which have occured.
394 static int DispatchEvents();
396 /** Dispatch trial reads and writes. This causes the actual socket I/O
397 * to happen when writes have been pre-buffered.
399 static void DispatchTrialWrites();
401 /** Returns true if the file descriptors in the given event handler are
402 * within sensible ranges which can be handled by the socket engine.
404 static bool BoundsCheckFd(EventHandler* eh);
406 /** Abstraction for BSD sockets accept(2).
407 * This function should emulate its namesake system call exactly.
408 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
409 * @param addr The client IP address and port
410 * @param addrlen The size of the sockaddr parameter.
411 * @return This method should return exactly the same values as the system call it emulates.
413 static int Accept(EventHandler* fd, sockaddr *addr, socklen_t *addrlen);
415 /** Close the underlying fd of an event handler, remove it from the socket engine and set the fd to -1.
416 * @param eh The EventHandler to close.
417 * @return 0 on success, a negative value on error
419 static int Close(EventHandler* eh);
421 /** Abstraction for BSD sockets close(2).
422 * This function should emulate its namesake system call exactly.
423 * This function should emulate its namesake system call exactly.
424 * @return This method should return exactly the same values as the system call it emulates.
426 static int Close(int fd);
428 /** Abstraction for BSD sockets send(2).
429 * This function should emulate its namesake system call exactly.
430 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
431 * @param buf The buffer in which the data that is sent is stored.
432 * @param len The size of the buffer.
433 * @param flags A flag value that controls the sending of the data.
434 * @return This method should return exactly the same values as the system call it emulates.
436 static int Send(EventHandler* fd, const void *buf, size_t len, int flags);
438 /** Abstraction for vector write function writev().
439 * This function should emulate its namesake system call exactly.
440 * @param fd EventHandler to send data with
441 * @param iov Array of IOVectors containing the buffers to send and their lengths in the platform's
443 * @param count Number of elements in iov.
444 * @return This method should return exactly the same values as the system call it emulates.
446 static int WriteV(EventHandler* fd, const IOVector* iov, int count);
449 /** Abstraction for vector write function writev() that accepts a POSIX format iovec.
450 * This function should emulate its namesake system call exactly.
451 * @param fd EventHandler to send data with
452 * @param iov Array of iovecs containing the buffers to send and their lengths in POSIX format.
453 * @param count Number of elements in iov.
454 * @return This method should return exactly the same values as the system call it emulates.
456 static int WriteV(EventHandler* fd, const iovec* iov, int count);
459 /** Abstraction for BSD sockets recv(2).
460 * This function should emulate its namesake system call exactly.
461 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
462 * @param buf The buffer in which the data that is read is stored.
463 * @param len The size of the buffer.
464 * @param flags A flag value that controls the reception of the data.
465 * @return This method should return exactly the same values as the system call it emulates.
467 static int Recv(EventHandler* fd, void *buf, size_t len, int flags);
469 /** Abstraction for BSD sockets recvfrom(2).
470 * This function should emulate its namesake system call exactly.
471 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
472 * @param buf The buffer in which the data that is read is stored.
473 * @param len The size of the buffer.
474 * @param flags A flag value that controls the reception of the data.
475 * @param from The remote IP address and port.
476 * @param fromlen The size of the from parameter.
477 * @return This method should return exactly the same values as the system call it emulates.
479 static int RecvFrom(EventHandler* fd, void *buf, size_t len, int flags, sockaddr *from, socklen_t *fromlen);
481 /** Abstraction for BSD sockets sendto(2).
482 * This function should emulate its namesake system call exactly.
483 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
484 * @param buf The buffer in which the data that is sent is stored.
485 * @param len The size of the buffer.
486 * @param flags A flag value that controls the sending of the data.
487 * @param to The remote IP address and port.
488 * @param tolen The size of the to parameter.
489 * @return This method should return exactly the same values as the system call it emulates.
491 static int SendTo(EventHandler* fd, const void *buf, size_t len, int flags, const sockaddr *to, socklen_t tolen);
493 /** Abstraction for BSD sockets connect(2).
494 * This function should emulate its namesake system call exactly.
495 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
496 * @param serv_addr The server IP address and port.
497 * @param addrlen The size of the sockaddr parameter.
498 * @return This method should return exactly the same values as the system call it emulates.
500 static int Connect(EventHandler* fd, const sockaddr *serv_addr, socklen_t addrlen);
502 /** Make a file descriptor blocking.
503 * @param fd a file descriptor to set to blocking mode
504 * @return 0 on success, -1 on failure, errno is set appropriately.
506 static int Blocking(int fd);
508 /** Make a file descriptor nonblocking.
509 * @param fd A file descriptor to set to nonblocking mode
510 * @return 0 on success, -1 on failure, errno is set appropriately.
512 static int NonBlocking(int fd);
514 /** Abstraction for BSD sockets shutdown(2).
515 * This function should emulate its namesake system call exactly.
516 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
517 * @param how What part of the socket to shut down
518 * @return This method should return exactly the same values as the system call it emulates.
520 static int Shutdown(EventHandler* fd, int how);
522 /** Abstraction for BSD sockets shutdown(2).
523 * This function should emulate its namesake system call exactly.
524 * @return This method should return exactly the same values as the system call it emulates.
526 static int Shutdown(int fd, int how);
528 /** Abstraction for BSD sockets bind(2).
529 * This function should emulate its namesake system call exactly.
530 * @return This method should return exactly the same values as the system call it emulates.
532 static int Bind(int fd, const irc::sockets::sockaddrs& addr);
534 /** Abstraction for BSD sockets listen(2).
535 * This function should emulate its namesake system call exactly.
536 * @return This method should return exactly the same values as the system call it emulates.
538 static int Listen(int sockfd, int backlog);
540 /** Set SO_REUSEADDR and SO_LINGER on this file descriptor
542 static void SetReuse(int sockfd);
544 /** This function is called immediately after fork().
545 * Some socket engines (notably kqueue) cannot have their
546 * handles inherited by forked processes. This method
547 * allows for the socket engine to re-create its handle
548 * after the daemon forks as the socket engine is created
549 * long BEFORE the daemon forks.
550 * @return void, but it is acceptable for this function to bail back to
551 * the shell or operating system on fatal error.
553 static void RecoverFromFork();
555 /** Get data transfer and event statistics
557 static const Statistics& GetStats() { return stats; }
559 /** Should we ignore the error in errno?
560 * Checks EAGAIN and WSAEWOULDBLOCK
562 static bool IgnoreError();
564 /** Return the last socket related error. strrerror(errno) on *nix
566 static std::string LastError();
568 /** Returns the error for the given error num, strerror(errnum) on *nix
570 static std::string GetError(int errnum);
573 inline bool SocketEngine::IgnoreError()
575 if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
579 if (WSAGetLastError() == WSAEWOULDBLOCK)