2 * IRC - Internet Relay Chat, ircd/list.c
3 * Copyright (C) 1990 Jarkko Oikarinen and
4 * University of Oulu, Finland
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 1, or (at your option)
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 * @brief Singly and doubly linked list manipulation implementation.
29 #include "ircd_alloc.h"
30 #include "ircd_events.h"
31 #include "ircd_reply.h"
32 #include "ircd_string.h"
48 #include <stddef.h> /* offsetof */
49 #include <unistd.h> /* close */
53 /** Stores linked list statistics for various types of lists. */
54 static struct liststats {
56 } clients, connections, users, servs, links;
59 /** Count of allocated Client structures. */
60 static unsigned int clientAllocCount;
61 /** Linked list of currently unused Client structures. */
62 static struct Client* clientFreeList;
64 /** Count of allocated Connection structures. */
65 static unsigned int connectionAllocCount;
66 /** Linked list of currently unused Connection structures. */
67 static struct Connection* connectionFreeList;
69 /** Count of allocated SLink structures. */
70 static unsigned int slinkAllocCount;
71 /** Linked list of currently unused SLink structures. */
72 static struct SLink* slinkFreeList;
74 /** Initialize the list manipulation support system.
75 * Pre-allocate MAXCONNECTIONS Client and Connection structures.
80 struct Connection* con;
83 * pre-allocate MAXCONNECTIONS clients and connections
85 for (i = 0; i < MAXCONNECTIONS; ++i) {
86 cptr = (struct Client*) MyMalloc(sizeof(struct Client));
87 cli_next(cptr) = clientFreeList;
88 clientFreeList = cptr;
91 con = (struct Connection*) MyMalloc(sizeof(struct Connection));
92 con_next(con) = connectionFreeList;
93 connectionFreeList = con;
94 ++connectionAllocCount;
98 memset(&clients, 0, sizeof(clients));
99 memset(&connections, 0, sizeof(connections));
100 memset(&users, 0, sizeof(users));
101 memset(&servs, 0, sizeof(servs));
102 memset(&links, 0, sizeof(links));
106 /** Allocate a new Client structure.
107 * If #clientFreeList != NULL, use the head of that list.
108 * Otherwise, allocate a new structure.
109 * @return Newly allocated Client.
111 static struct Client* alloc_client(void)
113 struct Client* cptr = clientFreeList;
116 cptr = (struct Client*) MyMalloc(sizeof(struct Client));
119 clientFreeList = cli_next(cptr);
125 memset(cptr, 0, sizeof(struct Client));
130 /** Release a Client structure by prepending it to #clientFreeList.
131 * @param[in] cptr Client that is no longer being used.
133 static void dealloc_client(struct Client* cptr)
135 assert(cli_verify(cptr));
136 assert(0 == cli_connect(cptr));
142 cli_next(cptr) = clientFreeList;
143 clientFreeList = cptr;
148 /** Allocate a new Connection structure.
149 * If #connectionFreeList != NULL, use the head of that list.
150 * Otherwise, allocate a new structure.
151 * @return Newly allocated Connection.
153 static struct Connection* alloc_connection(void)
155 struct Connection* con = connectionFreeList;
158 con = (struct Connection*) MyMalloc(sizeof(struct Connection));
159 ++connectionAllocCount;
161 connectionFreeList = con_next(con);
167 memset(con, 0, sizeof(struct Connection));
168 timer_init(&(con_proc(con)));
173 /** Release a Connection and all memory associated with it.
174 * The connection's DNS reply field is freed, its file descriptor is
175 * closed, its msgq and sendq are cleared, and its associated Listener
176 * is dereferenced. Then it is prepended to #connectionFreeList.
177 * @param[in] con Connection to free.
179 static void dealloc_connection(struct Connection* con)
181 assert(con_verify(con));
182 assert(!t_active(&(con_proc(con))));
183 assert(!t_onqueue(&(con_proc(con))));
185 Debug((DEBUG_LIST, "Deallocating connection %p", con));
187 if (con_dns_reply(con)) {
188 MyFree(con_dns_reply(con));
189 con_dns_reply(con) = 0;
191 if (-1 < con_fd(con))
193 MsgQClear(&(con_sendQ(con)));
194 client_drop_sendq(con);
195 DBufClear(&(con_recvQ(con)));
196 if (con_listener(con))
197 release_listener(con_listener(con));
203 con_next(con) = connectionFreeList;
204 connectionFreeList = con;
209 /** Allocate a new client and initialize it.
210 * If \a from == NULL, initialize the fields for a local client,
211 * including allocating a Connection for him; otherwise initialize the
212 * fields for a remote client..
213 * @param[in] from Server connection that introduced the client (or
215 * @param[in] status Initial Client::cli_status value.
216 * @return Newly allocated and initialized Client.
218 struct Client* make_client(struct Client *from, int status)
220 struct Client* cptr = 0;
221 struct Connection* con = 0;
223 assert(!from || cli_verify(from));
225 cptr = alloc_client();
228 assert(!cli_magic(cptr));
229 assert(0 == from || 0 != cli_connect(from));
231 if (!from) { /* local client, allocate a struct Connection */
232 con = alloc_connection();
235 assert(!con_magic(con));
237 con_magic(con) = CONNECTION_MAGIC;
238 con_fd(con) = -1; /* initialize struct Connection */
239 con_freeflag(con) = 0;
240 con_nextnick(con) = CurrentTime - NICK_DELAY;
241 con_nexttarget(con) = CurrentTime - (TARGET_DELAY * (STARTTARGETS - 1));
242 con_handler(con) = UNREGISTERED_HANDLER;
243 con_client(con) = cptr;
245 cli_local(cptr) = 1; /* Set certain fields of the struct Client */
246 cli_since(cptr) = cli_lasttime(cptr) = cli_firsttime(cptr) = CurrentTime;
247 cli_lastnick(cptr) = TStime();
249 con = cli_connect(from); /* use 'from's connection */
252 assert(con_verify(con));
254 cli_magic(cptr) = CLIENT_MAGIC;
255 cli_connect(cptr) = con; /* set the connection and other fields */
256 cli_status(cptr) = status;
257 cli_hnext(cptr) = cptr;
258 strcpy(cli_username(cptr), "unknown");
263 /** Release a Connection.
264 * @param[in] con Connection to free.
266 void free_connection(struct Connection* con)
271 assert(con_verify(con));
272 assert(0 == con_client(con));
274 dealloc_connection(con); /* deallocate the connection */
277 /** Release a Client.
278 * In addition to the cleanup done by dealloc_client(), this will free
279 * any pending auth request, free the connection for local clients,
280 * and delete the processing timer for the client.
281 * @param[in] cptr Client to free.
283 void free_client(struct Client* cptr)
288 * forget to remove the client from the hash table?
290 assert(cli_verify(cptr));
291 assert(cli_hnext(cptr) == cptr);
292 /* or from linked list? */
293 assert(cli_next(cptr) == 0);
294 assert(cli_prev(cptr) == 0);
296 Debug((DEBUG_LIST, "Freeing client %s [%p], connection %p", cli_name(cptr),
297 cptr, cli_connect(cptr)));
300 destroy_auth_request(cli_auth(cptr), 0);
302 /* Make sure we didn't magically get re-added to the list */
303 assert(cli_next(cptr) == 0);
304 assert(cli_prev(cptr) == 0);
306 if (cli_from(cptr) == cptr) { /* in other words, we're local */
308 /* timer must be marked as not active */
309 if (!cli_freeflag(cptr) && !t_active(&(cli_proc(cptr))))
310 dealloc_connection(cli_connect(cptr)); /* connection not open anymore */
312 if (-1 < cli_fd(cptr) && cli_freeflag(cptr) & FREEFLAG_SOCKET)
313 socket_del(&(cli_socket(cptr))); /* queue a socket delete */
314 if (cli_freeflag(cptr) & FREEFLAG_TIMER)
315 timer_del(&(cli_proc(cptr))); /* queue a timer delete */
319 cli_connect(cptr) = 0;
321 dealloc_client(cptr); /* actually destroy the client */
324 /** Allocate a new Server object for a client.
325 * If Client::cli_serv == NULL, allocate a Server structure for it and
327 * @param[in] cptr %Client to make into a server.
328 * @return The value of cli_serv(\a cptr).
330 struct Server *make_server(struct Client *cptr)
332 struct Server *serv = cli_serv(cptr);
334 assert(cli_verify(cptr));
338 serv = (struct Server*) MyMalloc(sizeof(struct Server));
340 memset(serv, 0, sizeof(struct Server)); /* All variables are 0 by default */
344 cli_serv(cptr) = serv;
345 cli_serv(cptr)->lag = 60000;
347 DupString(serv->last_error_msg, "<>"); /* String must be non-empty */
349 return cli_serv(cptr);
352 /** Remove \a cptr from lists that it is a member of.
353 * Specifically, this delinks \a cptr from #GlobalClientList, updates
354 * the whowas history list, frees its Client::cli_user and
355 * Client::cli_serv fields, and finally calls free_client() on it.
356 * @param[in] cptr Client to remove from lists and free.
358 void remove_client_from_list(struct Client *cptr)
360 assert(cli_verify(cptr));
361 assert(con_verify(cli_connect(cptr)));
362 assert(!cli_prev(cptr) || cli_verify(cli_prev(cptr)));
363 assert(!cli_next(cptr) || cli_verify(cli_next(cptr)));
366 /* Only try remove cptr from the list if it IS in the list.
367 * cli_next(cptr) cannot be NULL here, as &me is always the end
368 * the list, and we never remove &me. -GW
373 cli_next(cli_prev(cptr)) = cli_next(cptr);
375 GlobalClientList = cli_next(cptr);
376 cli_prev(GlobalClientList) = 0;
378 cli_prev(cli_next(cptr)) = cli_prev(cptr);
380 cli_next(cptr) = cli_prev(cptr) = 0;
382 if (IsUser(cptr) && cli_user(cptr)) {
383 add_history(cptr, 0);
386 if (cli_user(cptr)) {
387 free_user(cli_user(cptr));
391 if (cli_serv(cptr)) {
392 if (cli_serv(cptr)->user) {
393 free_user(cli_serv(cptr)->user);
394 cli_serv(cptr)->user = 0;
396 if (cli_serv(cptr)->client_list)
397 MyFree(cli_serv(cptr)->client_list);
398 MyFree(cli_serv(cptr)->last_error_msg);
399 MyFree(cli_serv(cptr));
407 /** Link \a cptr into #GlobalClientList.
408 * @param[in] cptr Client to link into the global list.
410 void add_client_to_list(struct Client *cptr)
412 assert(cli_verify(cptr));
413 assert(cli_next(cptr) == 0);
414 assert(cli_prev(cptr) == 0);
417 * Since we always insert new clients to the top of the list,
418 * this should mean the "me" is the bottom most item in the list.
419 * XXX - don't always count on the above, things change
422 cli_next(cptr) = GlobalClientList;
423 GlobalClientList = cptr;
425 cli_prev(cli_next(cptr)) = cptr;
429 /** Perform a very CPU-intensive verification of %GlobalClientList.
430 * This checks the Client::cli_magic and Client::cli_prev field for
431 * each element in the list, and also checks that there are no loops.
432 * Any detected error will lead to an assertion failure.
434 void verify_client_list(void)
436 struct Client *client, *prev = 0;
437 unsigned int visited = 0;
439 for (client = GlobalClientList; client; client = cli_next(client), ++visited) {
440 /* Verify that this is a valid client, not a free'd one */
441 assert(cli_verify(client));
442 /* Verify that the list hasn't suddenly jumped around */
443 assert(cli_prev(client) == prev);
444 /* Verify that the list hasn't become circular */
445 assert(cli_next(client) != GlobalClientList);
446 assert(visited <= clientAllocCount);
447 /* Remember what should preceed us */
451 #endif /* DEBUGMODE */
453 /** Find the list element that corresponds to a client.
454 * @param[in] lp Head of singly linked list.
455 * @param[in] ptr %Client to search for.
456 * @return SLink element from \a lp that contains \a ptr, or NULL if none exist.
458 struct SLink *find_user_link(struct SLink *lp, struct Client *ptr)
462 if (lp->value.cptr == ptr)
470 /** Allocate a new SLink element.
471 * Pulls from #slinkFreeList if it contains anything, else it
472 * allocates a new one from the heap.
473 * @return Newly allocated list element.
475 struct SLink* make_link(void)
477 struct SLink* lp = slinkFreeList;
479 slinkFreeList = lp->next;
481 lp = (struct SLink*) MyMalloc(sizeof(struct SLink));
491 /** Release a singly linked list element.
492 * @param[in] lp List element to mark as unused.
494 void free_link(struct SLink* lp)
497 lp->next = slinkFreeList;
505 /** Add an element to a doubly linked list.
506 * If \a lpp points to a non-NULL pointer, its DLink::prev field is
507 * updated to point to the newly allocated element. Regardless,
508 * \a lpp is overwritten with the pointer to the new link.
509 * @param[in,out] lpp Pointer to insertion location.
510 * @param[in] cp %Client to put in newly allocated element.
511 * @return Allocated link structure (same as \a lpp on output).
513 struct DLink *add_dlink(struct DLink **lpp, struct Client *cp)
515 struct DLink* lp = (struct DLink*) MyMalloc(sizeof(struct DLink));
519 if ((lp->next = *lpp))
525 /** Remove a node from a doubly linked list.
526 * @param[out] lpp Pointer to next list element.
527 * @param[in] lp List node to unlink.
529 void remove_dlink(struct DLink **lpp, struct DLink *lp)
535 if ((lp->prev->next = lp->next))
536 lp->next->prev = lp->prev;
538 else if ((*lpp = lp->next))
539 lp->next->prev = NULL;
544 /** Report memory usage of list elements to \a cptr.
545 * @param[in] cptr Client requesting information.
546 * @param[in] name Unused pointer.
548 void send_listinfo(struct Client *cptr, char *name)
550 int inuse = 0, mem = 0, tmp = 0;
552 send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG, ":Clients: inuse: %d(%d)",
553 clients.inuse, tmp = clients.inuse * sizeof(struct Client));
555 inuse += clients.inuse;
556 send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG, "Connections: inuse: %d(%d)",
558 tmp = connections.inuse * sizeof(struct Connection));
560 inuse += connections.inuse;
561 send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG, ":Users: inuse: %d(%d)",
562 users.inuse, tmp = users.inuse * sizeof(struct User));
564 inuse += users.inuse;
565 send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG, ":Servs: inuse: %d(%d)",
566 servs.inuse, tmp = servs.inuse * sizeof(struct Server));
568 inuse += servs.inuse;
569 send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG, ":Links: inuse: %d(%d)",
570 links.inuse, tmp = links.inuse * sizeof(struct SLink));
572 inuse += links.inuse;
573 send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG, ":Confs: inuse: %d(%d)",
574 GlobalConfCount, tmp = GlobalConfCount * sizeof(struct ConfItem));
576 inuse += GlobalConfCount;
577 send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG, ":Totals: inuse %d %d",