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 OnEventHandler*(), 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 OnEventHandler*() 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 OnEventHandlerRead() 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 OnEventHandlerRead().
116 FD_READ_WILL_BLOCK = 0x2000,
118 /** Add a trial write. During the next DispatchEvents invocation, this
119 * will call OnEventHandlerWrite() 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 OnEventHandlerWrite().
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 OnEventHandler*() methods. 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 OnEventHandler*() methods.
143 * The event mask passed to SocketEngine::AddFd() determines
144 * what events the EventHandler gets notified about and with
145 * what semantics. SocketEngine::ChangeEventMask() can be
146 * called to update the event mask later. The only
147 * requirement beyond this for an event handler is that it
148 * must have a file descriptor. What this file descriptor
149 * is actually attached to is completely up to you.
151 class CoreExport EventHandler : public classbase
154 /** Private state maintained by socket engine */
157 void SetEventMask(int mask) { event_mask = mask; }
161 * All events which can be handled must have a file descriptor. This
162 * allows you to add events for sockets, fifo's, pipes, and various
163 * other forms of IPC. Do not change this while the object is
164 * registered with the SocketEngine
168 /** Swaps the internals of this EventHandler with another one.
169 * @param other A EventHandler to swap internals with.
171 void SwapInternals(EventHandler& other);
174 /** Get the current file descriptor
175 * @return The file descriptor of this handler
177 inline int GetFd() const { return fd; }
179 inline int GetEventMask() const { return event_mask; }
181 /** Set a new file desciptor
182 * @param FD The new file descriptor. Do not call this method without
183 * first deleting the object from the SocketEngine if you have
184 * added it to a SocketEngine instance.
194 virtual ~EventHandler() {}
196 /** Called by the socket engine in case of a read event
198 virtual void OnEventHandlerRead() = 0;
200 /** Called by the socket engine in case of a write event.
201 * The default implementation does nothing.
203 virtual void OnEventHandlerWrite();
205 /** Called by the socket engine in case of an error event.
206 * The default implementation does nothing.
207 * @param errornum Error code
209 virtual void OnEventHandlerError(int errornum);
211 friend class SocketEngine;
214 /** Provides basic file-descriptor-based I/O support.
215 * The actual socketengine class presents the
216 * same interface on all operating systems, but
217 * its private members and internal behaviour
218 * should be treated as blackboxed, and vary
219 * from system to system and upon the config
220 * settings chosen by the server admin.
222 class CoreExport SocketEngine
225 /** Socket engine statistics: count of various events, bandwidth usage
229 mutable size_t indata;
230 mutable size_t outdata;
231 mutable time_t lastempty;
233 /** Reset the byte counters and lastempty if there wasn't a reset in this second.
235 void CheckFlush() const;
238 /** Constructor, initializes member vars except indata and outdata because those are set to 0
239 * in CheckFlush() the first time Update() or GetBandwidth() is called.
241 Statistics() : lastempty(0), TotalEvents(0), ReadEvents(0), WriteEvents(0), ErrorEvents(0) { }
243 /** Update counters for network data received.
244 * This should be called after every read-type syscall.
245 * @param len_in Number of bytes received, or -1 for error, as typically
246 * returned by a read-style syscall.
248 void UpdateReadCounters(int len_in);
250 /** Update counters for network data sent.
251 * This should be called after every write-type syscall.
252 * @param len_out Number of bytes sent, or -1 for error, as typically
253 * returned by a read-style syscall.
255 void UpdateWriteCounters(int len_out);
257 /** Get data transfer statistics.
258 * @param kbitpersec_in Filled with incoming traffic in this second in kbit/s.
259 * @param kbitpersec_out Filled with outgoing traffic in this second in kbit/s.
260 * @param kbitpersec_total Filled with total traffic in this second in kbit/s.
262 void CoreExport GetBandwidth(float& kbitpersec_in, float& kbitpersec_out, float& kbitpersec_total) const;
264 unsigned long TotalEvents;
265 unsigned long ReadEvents;
266 unsigned long WriteEvents;
267 unsigned long ErrorEvents;
271 /** Reference table, contains all current handlers
273 static std::vector<EventHandler*> ref;
275 /** Current number of descriptors in the engine. */
276 static size_t CurrentSetSize;
278 /** The maximum number of descriptors in the engine. */
279 static size_t MaxSetSize;
281 /** List of handlers that want a trial read/write
283 static std::set<int> trials;
285 /** Socket engine statistics: count of various events, bandwidth usage
287 static Statistics stats;
289 /** Look up the fd limit using rlimit. */
290 static void LookupMaxFds();
292 /** Terminates the program when the socket engine fails to initialize. */
293 static void InitError();
295 static void OnSetEvent(EventHandler* eh, int old_mask, int new_mask);
297 /** Add an event handler to the base socket engine. AddFd(EventHandler*, int) should call this.
299 static bool AddFdRef(EventHandler* eh);
301 static void DelFdRef(EventHandler* eh);
303 template <typename T>
304 static void ResizeDouble(std::vector<T>& vect)
306 if (SocketEngine::CurrentSetSize > vect.size())
307 vect.resize(SocketEngine::CurrentSetSize * 2);
312 typedef iovec IOVector;
314 typedef WindowsIOVec IOVector;
318 * The constructor transparently initializes
319 * the socket engine which the ircd is using.
320 * Please note that if there is a catastrophic
321 * failure (for example, you try and enable
322 * epoll on a 2.4 linux kernel) then this
323 * function may bail back to the shell.
324 * @return void, but it is acceptable for this function to bail back to
325 * the shell or operating system on fatal error.
330 * The destructor transparently tidies up
331 * any resources used by the socket engine.
333 static void Deinit();
335 /** Add an EventHandler object to the engine. Use AddFd to add a file
336 * descriptor to the engine and have the socket engine monitor it. You
337 * must provide an object derived from EventHandler which implements
338 * the required OnEventHandler*() methods.
339 * @param eh An event handling object to add
340 * @param event_mask The initial event mask for the object
342 static bool AddFd(EventHandler* eh, int event_mask);
344 /** If you call this function and pass it an
345 * event handler, that event handler will
346 * receive the next available write event,
347 * even if the socket is a readable socket only.
348 * Developers should avoid constantly keeping
349 * an eventhandler in the writeable state,
350 * as this will consume large amounts of
352 * @param eh The event handler to change
353 * @param event_mask The changes to make to the wait state
355 static void ChangeEventMask(EventHandler* eh, int event_mask);
357 /** Returns the number of file descriptors reported by the system this program may use
358 * when it was started.
359 * @return If non-zero the number of file descriptors that the system reported that we
362 static size_t GetMaxFds() { return MaxSetSize; }
364 /** Returns the number of file descriptors being queried
365 * @return The set size
367 static size_t GetUsedFds() { return CurrentSetSize; }
369 /** Delete an event handler from the engine.
370 * This function call deletes an EventHandler
371 * from the engine, returning true if it succeeded
372 * and false if it failed. This does not free the
373 * EventHandler pointer using delete, if this is
374 * required you must do this yourself.
375 * @param eh The event handler object to remove
377 static void DelFd(EventHandler* eh);
379 /** Returns true if a file descriptor exists in
380 * the socket engine's list.
381 * @param fd The event handler to look for
382 * @return True if this fd has an event handler
384 static bool HasFd(int fd);
386 /** Returns the EventHandler attached to a specific fd.
387 * If the fd isnt in the socketengine, returns NULL.
388 * @param fd The event handler to look for
389 * @return A pointer to the event handler, or NULL
391 static EventHandler* GetRef(int fd);
393 /** Waits for events and dispatches them to handlers. Please note that
394 * this doesn't wait long, only a couple of milliseconds. It returns the
395 * number of events which occurred during this call. This method will
396 * dispatch events to their handlers by calling their
397 * EventHandler::OnEventHandler*() methods.
398 * @return The number of events which have occured.
400 static int DispatchEvents();
402 /** Dispatch trial reads and writes. This causes the actual socket I/O
403 * to happen when writes have been pre-buffered.
405 static void DispatchTrialWrites();
407 /** Returns true if the file descriptors in the given event handler are
408 * within sensible ranges which can be handled by the socket engine.
410 static bool BoundsCheckFd(EventHandler* eh);
412 /** Abstraction for BSD sockets accept(2).
413 * This function should emulate its namesake system call exactly.
414 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
415 * @param addr The client IP address and port
416 * @param addrlen The size of the sockaddr parameter.
417 * @return This method should return exactly the same values as the system call it emulates.
419 static int Accept(EventHandler* fd, sockaddr *addr, socklen_t *addrlen);
421 /** Close the underlying fd of an event handler, remove it from the socket engine and set the fd to -1.
422 * @param eh The EventHandler to close.
423 * @return 0 on success, a negative value on error
425 static int Close(EventHandler* eh);
427 /** Abstraction for BSD sockets close(2).
428 * This function should emulate its namesake system call exactly.
429 * This function should emulate its namesake system call exactly.
430 * @return This method should return exactly the same values as the system call it emulates.
432 static int Close(int fd);
434 /** Abstraction for BSD sockets send(2).
435 * This function should emulate its namesake system call exactly.
436 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
437 * @param buf The buffer in which the data that is sent is stored.
438 * @param len The size of the buffer.
439 * @param flags A flag value that controls the sending of the data.
440 * @return This method should return exactly the same values as the system call it emulates.
442 static int Send(EventHandler* fd, const void *buf, size_t len, int flags);
444 /** Abstraction for vector write function writev().
445 * This function should emulate its namesake system call exactly.
446 * @param fd EventHandler to send data with
447 * @param iov Array of IOVectors containing the buffers to send and their lengths in the platform's
449 * @param count Number of elements in iov.
450 * @return This method should return exactly the same values as the system call it emulates.
452 static int WriteV(EventHandler* fd, const IOVector* iov, int count);
455 /** Abstraction for vector write function writev() that accepts a POSIX format iovec.
456 * This function should emulate its namesake system call exactly.
457 * @param fd EventHandler to send data with
458 * @param iov Array of iovecs containing the buffers to send and their lengths in POSIX format.
459 * @param count Number of elements in iov.
460 * @return This method should return exactly the same values as the system call it emulates.
462 static int WriteV(EventHandler* fd, const iovec* iov, int count);
465 /** Abstraction for BSD sockets recv(2).
466 * This function should emulate its namesake system call exactly.
467 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
468 * @param buf The buffer in which the data that is read is stored.
469 * @param len The size of the buffer.
470 * @param flags A flag value that controls the reception of the data.
471 * @return This method should return exactly the same values as the system call it emulates.
473 static int Recv(EventHandler* fd, void *buf, size_t len, int flags);
475 /** Abstraction for BSD sockets recvfrom(2).
476 * This function should emulate its namesake system call exactly.
477 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
478 * @param buf The buffer in which the data that is read is stored.
479 * @param len The size of the buffer.
480 * @param flags A flag value that controls the reception of the data.
481 * @param from The remote IP address and port.
482 * @param fromlen The size of the from parameter.
483 * @return This method should return exactly the same values as the system call it emulates.
485 static int RecvFrom(EventHandler* fd, void *buf, size_t len, int flags, sockaddr *from, socklen_t *fromlen);
487 /** Abstraction for BSD sockets sendto(2).
488 * This function should emulate its namesake system call exactly.
489 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
490 * @param buf The buffer in which the data that is sent is stored.
491 * @param len The size of the buffer.
492 * @param flags A flag value that controls the sending of the data.
493 * @param address The remote IP address and port.
494 * @return This method should return exactly the same values as the system call it emulates.
496 static int SendTo(EventHandler* fd, const void* buf, size_t len, int flags, const irc::sockets::sockaddrs& address);
498 /** Abstraction for BSD sockets connect(2).
499 * This function should emulate its namesake system call exactly.
500 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
501 * @param address The server IP address and port.
502 * @return This method should return exactly the same values as the system call it emulates.
504 static int Connect(EventHandler* fd, const irc::sockets::sockaddrs& address);
506 /** Make a file descriptor blocking.
507 * @param fd a file descriptor to set to blocking mode
508 * @return 0 on success, -1 on failure, errno is set appropriately.
510 static int Blocking(int fd);
512 /** Make a file descriptor nonblocking.
513 * @param fd A file descriptor to set to nonblocking mode
514 * @return 0 on success, -1 on failure, errno is set appropriately.
516 static int NonBlocking(int fd);
518 /** Abstraction for BSD sockets shutdown(2).
519 * This function should emulate its namesake system call exactly.
520 * @param fd This version of the call takes an EventHandler instead of a bare file descriptor.
521 * @param how What part of the socket to shut down
522 * @return This method should return exactly the same values as the system call it emulates.
524 static int Shutdown(EventHandler* fd, int how);
526 /** Abstraction for BSD sockets shutdown(2).
527 * This function should emulate its namesake system call exactly.
528 * @return This method should return exactly the same values as the system call it emulates.
530 static int Shutdown(int fd, int how);
532 /** Abstraction for BSD sockets bind(2).
533 * This function should emulate its namesake system call exactly.
534 * @return This method should return exactly the same values as the system call it emulates.
536 static int Bind(int fd, const irc::sockets::sockaddrs& addr);
538 /** Abstraction for BSD sockets listen(2).
539 * This function should emulate its namesake system call exactly.
540 * @return This method should return exactly the same values as the system call it emulates.
542 static int Listen(int sockfd, int backlog);
544 /** Set SO_REUSEADDR and SO_LINGER on this file descriptor
546 static void SetReuse(int sockfd);
548 /** This function is called immediately after fork().
549 * Some socket engines (notably kqueue) cannot have their
550 * handles inherited by forked processes. This method
551 * allows for the socket engine to re-create its handle
552 * after the daemon forks as the socket engine is created
553 * long BEFORE the daemon forks.
554 * @return void, but it is acceptable for this function to bail back to
555 * the shell or operating system on fatal error.
557 static void RecoverFromFork();
559 /** Get data transfer and event statistics
561 static const Statistics& GetStats() { return stats; }
563 /** Should we ignore the error in errno?
564 * Checks EAGAIN and WSAEWOULDBLOCK
566 static bool IgnoreError();
568 /** Return the last socket related error. strrerror(errno) on *nix
570 static std::string LastError();
572 /** Returns the error for the given error num, strerror(errnum) on *nix
574 static std::string GetError(int errnum);
577 inline bool SocketEngine::IgnoreError()
579 if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
583 if (WSAGetLastError() == WSAEWOULDBLOCK)