1 /************************************************************************
2 * IRC - Internet Relay Chat, src/listener.c
3 * Copyright (C) 1999 Thomas Helvey <tomh@inxpress.net>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 1, or (at your option)
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 * @brief Implementation for handling listening sockets.
28 #include "ircd_alloc.h"
29 #include "ircd_events.h"
30 #include "ircd_features.h"
32 #include "ircd_osdep.h"
33 #include "ircd_reply.h"
34 #include "ircd_snprintf.h"
35 #include "ircd_string.h"
43 #include "sys.h" /* MAXCLIENTS */
45 /* #include <assert.h> -- Now using assert in ircd_log.h */
52 #include <sys/socket.h>
53 #include <arpa/inet.h>
55 /** List of listening sockets. */
56 struct Listener* ListenerPollList = 0;
58 static void accept_connection(struct Event* ev);
60 /** Allocate and initialize a new Listener structure for a particular
62 * @param[in] port Port number to listen on.
63 * @param[in] addr Local address to listen on.
64 * @return Newly allocated and initialized Listener.
66 static struct Listener* make_listener(int port, const struct irc_in_addr *addr)
68 struct Listener* listener =
69 (struct Listener*) MyMalloc(sizeof(struct Listener));
70 assert(0 != listener);
72 memset(listener, 0, sizeof(struct Listener));
75 listener->addr.port = port;
76 memcpy(&listener->addr.addr, addr, sizeof(listener->addr.addr));
78 #ifdef NULL_POINTER_NOT_ZERO
79 listener->next = NULL;
80 listener->conf = NULL;
85 /** Deallocate a Listener structure.
86 * @param[in] listener Listener to be freed.
88 static void free_listener(struct Listener* listener)
90 assert(0 != listener);
94 /** Maximum length for a port number. */
95 #define PORTNAMELEN 10 /* ":31337" */
97 /** Return displayable listener name and port.
98 * @param[in] listener %Listener to format as a text string.
99 * @return Pointer to a static buffer that contains "server.name:6667".
101 const char* get_listener_name(const struct Listener* listener)
103 static char buf[HOSTLEN + PORTNAMELEN + 4];
104 assert(0 != listener);
105 ircd_snprintf(0, buf, sizeof(buf), "%s:%u", cli_name(&me), listener->addr.port);
109 /** Count allocated listeners and the memory they use.
110 * @param[out] count_out Receives number of allocated listeners.
111 * @param[out] size_out Receives bytes used by listeners.
113 void count_listener_memory(int* count_out, size_t* size_out)
117 assert(0 != count_out);
118 assert(0 != size_out);
119 for (l = ListenerPollList; l; l = l->next)
122 *size_out = count * sizeof(struct Listener);
125 /** Report listening ports to a client.
126 * @param[in] sptr Client requesting statistics.
127 * @param[in] sd Stats descriptor for request (ignored).
128 * @param[in] param Extra parameter from user (port number to search for).
130 void show_ports(struct Client* sptr, const struct StatDesc* sd,
133 struct Listener *listener = 0;
135 int show_hidden = IsOper(sptr);
136 int count = (IsOper(sptr) || MyUser(sptr)) ? 100 : 8;
144 for (listener = ListenerPollList; listener; listener = listener->next) {
145 if (port && port != listener->addr.port)
147 flags[0] = (listener->server) ? 'S' : 'C';
148 if (listener->hidden) {
157 send_reply(sptr, RPL_STATSPLINE, listener->addr.port, listener->ref_count,
158 flags, (listener->active) ? "active" : "disabled");
165 * inetport - create a listener socket in the AF_INET domain,
166 * bind it to the port given in 'port' and listen to it
167 * returns true (1) if successful false (0) on error.
169 * If the operating system has a define for SOMAXCONN, use it, otherwise
170 * use HYBRID_SOMAXCONN -Dianora
171 * NOTE: Do this in os_xxxx.c files
174 #define HYBRID_SOMAXCONN SOMAXCONN
176 /** Maximum length of socket connection backlog. */
177 #define HYBRID_SOMAXCONN 64
180 /** Open listening socket for \a listener.
181 * @param[in,out] listener Listener to make a socket for.
182 * @return Non-zero on success, zero on failure.
184 static int inetport(struct Listener* listener)
189 * At first, open a new socket
191 fd = os_socket(&listener->addr, SOCK_STREAM, get_listener_name(listener));
195 * Set the buffer sizes for the listener. Accepted connections
196 * inherit the accepting sockets settings for SO_RCVBUF S_SNDBUF
197 * The window size is set during the SYN ACK so setting it anywhere
198 * else has no effect whatsoever on the connection.
199 * NOTE: this must be set before listen is called
201 if (!os_set_sockbufs(fd,
202 (listener->server) ? feature_int(FEAT_SOCKSENDBUF) : CLIENT_TCP_WINDOW,
203 (listener->server) ? feature_int(FEAT_SOCKRECVBUF) : CLIENT_TCP_WINDOW)) {
204 report_error(SETBUFS_ERROR_MSG, get_listener_name(listener), errno);
208 if (!os_set_listen(fd, HYBRID_SOMAXCONN)) {
209 report_error(LISTEN_ERROR_MSG, get_listener_name(listener), errno);
214 * Set the TOS bits - this is nonfatal if it doesn't stick.
216 if (!os_set_tos(fd,feature_int((listener->server)?FEAT_TOS_SERVER : FEAT_TOS_CLIENT))) {
217 report_error(TOS_ERROR_MSG, get_listener_name(listener), errno);
220 if (!socket_add(&listener->socket, accept_connection, (void*) listener,
221 SS_LISTENING, 0, fd)) {
222 /* Error should already have been reported to the logs */
232 /** Find the listener (if any) for a particular port and address.
233 * @param[in] port Port number to search for.
234 * @param[in] addr Local address to search for.
235 * @return Listener that matches (or NULL if none match).
237 static struct Listener* find_listener(int port, const struct irc_in_addr *addr)
239 struct Listener* listener;
240 for (listener = ListenerPollList; listener; listener = listener->next) {
241 if (port == listener->addr.port && !memcmp(addr, &listener->addr.addr, sizeof(*addr)))
247 /** Make sure we have a listener for \a port on \a vhost_ip.
248 * If one does not exist, create it. Then mark it as active and set
249 * the peer mask, server, and hidden flags according to the other
251 * @param[in] port Port number to listen on.
252 * @param[in] vhost_ip Local address to listen on.
253 * @param[in] mask Address mask to accept connections from.
254 * @param[in] is_server Non-zero if the port should only accept server connections.
255 * @param[in] is_hidden Non-zero if the port should be hidden from /STATS P output.
257 void add_listener(int port, const char* vhost_ip, const char* mask,
258 int is_server, int is_hidden)
260 struct Listener* listener;
261 struct irc_in_addr vaddr;
264 * if no port in conf line, don't bother
269 memset(&vaddr, 0, sizeof(vaddr));
271 if (!EmptyString(vhost_ip)
272 && strcmp(vhost_ip, "*")
273 && !ircd_aton(&vaddr, vhost_ip))
276 listener = find_listener(port, &vaddr);
278 listener = make_listener(port, &vaddr);
279 listener->active = 1;
280 listener->hidden = is_hidden;
281 listener->server = is_server;
283 ipmask_parse(mask, &listener->mask, &listener->mask_bits);
285 listener->mask_bits = 0;
287 if (listener->fd >= 0) {
288 /* If the listener is already open, do not try to re-open. */
290 else if (inetport(listener)) {
291 listener->next = ListenerPollList;
292 ListenerPollList = listener;
295 free_listener(listener);
298 /** Mark all listeners as closing (inactive).
299 * This is done so unused listeners are closed after a rehash.
301 void mark_listeners_closing(void)
303 struct Listener* listener;
304 for (listener = ListenerPollList; listener; listener = listener->next)
305 listener->active = 0;
308 /** Close a single listener.
309 * @param[in] listener Listener to close.
311 void close_listener(struct Listener* listener)
313 assert(0 != listener);
315 * remove from listener list
317 if (listener == ListenerPollList)
318 ListenerPollList = listener->next;
320 struct Listener* prev = ListenerPollList;
321 for ( ; prev; prev = prev->next) {
322 if (listener == prev->next) {
323 prev->next = listener->next;
328 if (-1 < listener->fd)
330 socket_del(&listener->socket);
333 /** Close all inactive listeners. */
334 void close_listeners()
336 struct Listener* listener;
337 struct Listener* listener_next = 0;
339 * close all 'extra' listening ports we have
341 for (listener = ListenerPollList; listener; listener = listener_next) {
342 listener_next = listener->next;
343 if (0 == listener->active && 0 == listener->ref_count)
344 close_listener(listener);
348 /** Dereference the listener previously associated with a client.
349 * @param[in] listener Listener to dereference.
351 void release_listener(struct Listener* listener)
353 assert(0 != listener);
354 assert(0 < listener->ref_count);
355 if (0 == --listener->ref_count && !listener->active)
356 close_listener(listener);
359 /** Accept a connection on a listener.
360 * @param[in] ev Socket callback structure.
362 static void accept_connection(struct Event* ev)
364 struct Listener* listener;
365 struct irc_sockaddr addr;
368 assert(0 != ev_socket(ev));
369 assert(0 != s_data(ev_socket(ev)));
371 listener = (struct Listener*) s_data(ev_socket(ev));
373 if (ev_type(ev) == ET_DESTROY) /* being destroyed */
374 free_listener(listener);
376 assert(ev_type(ev) == ET_ACCEPT || ev_type(ev) == ET_ERROR);
378 listener->last_accept = CurrentTime;
380 * There may be many reasons for error return, but
381 * in otherwise correctly working environment the
382 * probable cause is running out of file descriptors
383 * (EMFILE, ENFILE or others?). The man pages for
384 * accept don't seem to list these as possible,
385 * although it's obvious that it may happen here.
386 * Thus no specific errors are tested at this
387 * point, just assume that connections cannot
388 * be accepted until some old is closed first.
390 * This piece of code implements multi-accept, based
391 * on the idea that poll/select can only be efficient,
392 * if we succeed in handling all available events,
393 * i.e. accept all pending connections.
395 * http://www.hpl.hp.com/techreports/2000/HPL-2000-174.html
399 if ((fd = os_accept(listener->fd, &addr)) == -1)
401 if (errno == EAGAIN ||
403 errno == EWOULDBLOCK)
406 /* Lotsa admins seem to have problems with not giving enough file
407 * descriptors to their server so we'll add a generic warning mechanism
408 * here. If it turns out too many messages are generated for
409 * meaningless reasons we can filter them back.
411 sendto_opmask_butone(0, SNO_TCPCOMMON,
412 "Unable to accept connection: %m");
416 * check for connection limit. If this fd exceeds the limit,
417 * all further accept()ed connections will also exceed it.
418 * Enable the server to clear out other connections before
419 * continuing to accept() new connections.
421 if (fd > MAXCLIENTS - 1)
423 ++ServerStats->is_ref;
424 send(fd, "ERROR :All connections in use\r\n", 32, 0);
429 * check to see if listener is shutting down. Continue
430 * to accept(), because it makes sense to clear our the
431 * socket's queue as fast as possible.
433 if (!listener->active)
435 ++ServerStats->is_ref;
436 send(fd, "ERROR :Use another port\r\n", 25, 0);
441 * check to see if connection is allowed for this address mask
443 if (!ipmask_check(&addr.addr, &listener->mask, listener->mask_bits))
445 ++ServerStats->is_ref;
446 send(fd, "ERROR :Use another port\r\n", 25, 0);
450 ++ServerStats->is_ac;
451 /* nextping = CurrentTime; */
452 add_connection(listener, fd);