]>
Commit | Line | Data |
---|---|---|
189935b1 | 1 | /* |
2 | * IRC - Internet Relay Chat, ircd/m_nick.c | |
3 | * Copyright (C) 1990 Jarkko Oikarinen and | |
4 | * University of Oulu, Computing Center | |
5 | * | |
6 | * See file AUTHORS in IRC package for additional names of | |
7 | * the programmers. | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 1, or (at your option) | |
12 | * any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to the Free Software | |
21 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
22 | * | |
23 | * $Id: m_nick.c,v 1.25 2005/03/19 23:22:09 entrope Exp $ | |
24 | */ | |
25 | ||
26 | /* | |
27 | * m_functions execute protocol messages on this server: | |
28 | * | |
29 | * cptr is always NON-NULL, pointing to a *LOCAL* client | |
30 | * structure (with an open socket connected!). This | |
31 | * identifies the physical socket where the message | |
32 | * originated (or which caused the m_function to be | |
33 | * executed--some m_functions may call others...). | |
34 | * | |
35 | * sptr is the source of the message, defined by the | |
36 | * prefix part of the message if present. If not | |
37 | * or prefix not found, then sptr==cptr. | |
38 | * | |
39 | * (!IsServer(cptr)) => (cptr == sptr), because | |
40 | * prefixes are taken *only* from servers... | |
41 | * | |
42 | * (IsServer(cptr)) | |
43 | * (sptr == cptr) => the message didn't | |
44 | * have the prefix. | |
45 | * | |
46 | * (sptr != cptr && IsServer(sptr) means | |
47 | * the prefix specified servername. (?) | |
48 | * | |
49 | * (sptr != cptr && !IsServer(sptr) means | |
50 | * that message originated from a remote | |
51 | * user (not local). | |
52 | * | |
53 | * combining | |
54 | * | |
55 | * (!IsServer(sptr)) means that, sptr can safely | |
56 | * taken as defining the target structure of the | |
57 | * message in this server. | |
58 | * | |
59 | * *Always* true (if 'parse' and others are working correct): | |
60 | * | |
61 | * 1) sptr->from == cptr (note: cptr->from == cptr) | |
62 | * | |
63 | * 2) MyConnect(sptr) <=> sptr == cptr (e.g. sptr | |
64 | * *cannot* be a local connection, unless it's | |
65 | * actually cptr!). [MyConnect(x) should probably | |
66 | * be defined as (x == x->from) --msa ] | |
67 | * | |
68 | * parc number of variable parameter strings (if zero, | |
69 | * parv is allowed to be NULL) | |
70 | * | |
71 | * parv a NULL terminated list of parameter pointers, | |
72 | * | |
73 | * parv[0], sender (prefix string), if not present | |
74 | * this points to an empty string. | |
75 | * parv[1]...parv[parc-1] | |
76 | * pointers to additional parameters | |
77 | * parv[parc] == NULL, *always* | |
78 | * | |
79 | * note: it is guaranteed that parv[0]..parv[parc-1] are all | |
80 | * non-NULL pointers. | |
81 | */ | |
82 | #include "config.h" | |
83 | ||
84 | #include "IPcheck.h" | |
85 | #include "client.h" | |
86 | #include "hash.h" | |
87 | #include "ircd.h" | |
88 | #include "ircd_chattr.h" | |
89 | #include "ircd_features.h" | |
90 | #include "ircd_log.h" | |
91 | #include "ircd_reply.h" | |
92 | #include "ircd_string.h" | |
93 | #include "msg.h" | |
94 | #include "numeric.h" | |
95 | #include "numnicks.h" | |
96 | #include "s_debug.h" | |
97 | #include "s_misc.h" | |
98 | #include "s_user.h" | |
99 | #include "send.h" | |
100 | #include "sys.h" | |
101 | ||
102 | /* #include <assert.h> -- Now using assert in ircd_log.h */ | |
103 | #include <stdlib.h> | |
104 | #include <string.h> | |
105 | ||
106 | /* | |
107 | * 'do_nick_name' ensures that the given parameter (nick) is really a proper | |
108 | * string for a nickname (note, the 'nick' may be modified in the process...) | |
109 | * | |
110 | * RETURNS the length of the final NICKNAME (0, if nickname is invalid) | |
111 | * | |
112 | * Nickname characters are in range 'A'..'}', '_', '-', '0'..'9' | |
113 | * anything outside the above set will terminate nickname. | |
114 | * In addition, the first character cannot be '-' or a Digit. | |
115 | * | |
116 | * Note: | |
117 | * The '~'-character should be allowed, but a change should be global, | |
118 | * some confusion would result if only few servers allowed it... | |
119 | */ | |
120 | static int do_nick_name(char* nick) | |
121 | { | |
122 | char* ch = nick; | |
123 | char* end = ch + NICKLEN; | |
124 | assert(0 != ch); | |
125 | ||
126 | /* first character in [0..9-] */ | |
127 | if (*ch == '-' || IsDigit(*ch)) | |
128 | return 0; | |
129 | for ( ; (ch < end) && *ch; ++ch) | |
130 | if (!IsNickChar(*ch)) | |
131 | break; | |
132 | ||
133 | *ch = '\0'; | |
134 | ||
135 | return (ch - nick); | |
136 | } | |
137 | ||
138 | /* | |
139 | * m_nick - message handler for local clients | |
140 | * parv[0] = sender prefix | |
141 | * parv[1] = nickname | |
142 | */ | |
143 | int m_nick(struct Client* cptr, struct Client* sptr, int parc, char* parv[]) | |
144 | { | |
145 | struct Client* acptr; | |
146 | char nick[NICKLEN + 2]; | |
147 | char* arg; | |
148 | char* s; | |
149 | const char* client_name; | |
150 | ||
151 | assert(0 != cptr); | |
152 | assert(cptr == sptr); | |
153 | ||
154 | /* | |
155 | * parv[0] will be empty for clients connecting for the first time | |
156 | */ | |
157 | client_name = (*(cli_name(sptr))) ? cli_name(sptr) : "*"; | |
158 | ||
159 | if (parc < 2) { | |
160 | send_reply(sptr, ERR_NONICKNAMEGIVEN); | |
161 | return 0; | |
162 | } | |
163 | /* | |
164 | * Don't let them send make us send back a really long string of | |
165 | * garbage | |
166 | */ | |
167 | arg = parv[1]; | |
168 | if (strlen(arg) > IRCD_MIN(NICKLEN, feature_int(FEAT_NICKLEN))) | |
169 | arg[IRCD_MIN(NICKLEN, feature_int(FEAT_NICKLEN))] = '\0'; | |
170 | ||
171 | if ((s = strchr(arg, '~'))) | |
172 | *s = '\0'; | |
173 | ||
174 | strcpy(nick, arg); | |
175 | ||
176 | /* | |
177 | * If do_nick_name() returns a null name then reject it. | |
178 | */ | |
179 | if (0 == do_nick_name(nick)) { | |
180 | send_reply(sptr, ERR_ERRONEUSNICKNAME, arg); | |
181 | return 0; | |
182 | } | |
183 | ||
184 | /* | |
185 | * Check if this is a LOCAL user trying to use a reserved (Juped) | |
186 | * nick, if so tell him that it's a nick in use... | |
187 | */ | |
188 | if (isNickJuped(nick)) { | |
189 | send_reply(sptr, ERR_NICKNAMEINUSE, nick); | |
190 | return 0; /* NICK message ignored */ | |
191 | } | |
192 | ||
193 | if (!(acptr = FindClient(nick))) { | |
194 | /* | |
195 | * No collisions, all clear... | |
196 | */ | |
197 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
198 | } | |
199 | if (IsServer(acptr)) { | |
200 | send_reply(sptr, ERR_NICKNAMEINUSE, nick); | |
201 | return 0; /* NICK message ignored */ | |
202 | } | |
203 | /* | |
204 | * If acptr == sptr, then we have a client doing a nick | |
205 | * change between *equivalent* nicknames as far as server | |
206 | * is concerned (user is changing the case of his/her | |
207 | * nickname or somesuch) | |
208 | */ | |
209 | if (acptr == sptr) { | |
210 | /* | |
211 | * If acptr == sptr, then we have a client doing a nick | |
212 | * change between *equivalent* nicknames as far as server | |
213 | * is concerned (user is changing the case of his/her | |
214 | * nickname or somesuch) | |
215 | */ | |
216 | if (0 != strcmp(cli_name(acptr), nick)) { | |
217 | /* | |
218 | * Allows change of case in his/her nick | |
219 | */ | |
220 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
221 | } | |
222 | /* | |
223 | * This is just ':old NICK old' type thing. | |
224 | * Just forget the whole thing here. There is | |
225 | * no point forwarding it to anywhere, | |
226 | * especially since servers prior to this | |
227 | * version would treat it as nick collision. | |
228 | */ | |
229 | return 0; | |
230 | } | |
231 | /* | |
232 | * Note: From this point forward it can be assumed that | |
233 | * acptr != sptr (point to different client structures). | |
234 | */ | |
235 | assert(acptr != sptr); | |
236 | /* | |
237 | * If the older one is "non-person", the new entry is just | |
238 | * allowed to overwrite it. Just silently drop non-person, | |
239 | * and proceed with the nick. This should take care of the | |
240 | * "dormant nick" way of generating collisions... | |
241 | * | |
242 | * XXX - hmmm can this happen after one is registered? | |
243 | * | |
244 | * Yes, client 1 connects to IRC and registers, client 2 connects and | |
245 | * sends "NICK foo" but doesn't send anything more. client 1 now does | |
246 | * /nick foo, they should succeed and client 2 gets disconnected with | |
247 | * the message below. | |
248 | */ | |
249 | if (IsUnknown(acptr) && MyConnect(acptr)) { | |
250 | ServerStats->is_ref++; | |
251 | IPcheck_connect_fail(acptr); | |
252 | exit_client(cptr, acptr, &me, "Overridden by other sign on"); | |
253 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
254 | } | |
255 | /* | |
256 | * NICK is coming from local client connection. Just | |
257 | * send error reply and ignore the command. | |
258 | */ | |
259 | send_reply(sptr, ERR_NICKNAMEINUSE, nick); | |
260 | return 0; /* NICK message ignored */ | |
261 | } | |
262 | ||
263 | ||
264 | /* | |
265 | * ms_nick - server message handler for nicks | |
266 | * parv[0] = sender prefix | |
267 | * parv[1] = nickname | |
268 | * | |
269 | * If from server, source is client: | |
270 | * parv[2] = timestamp | |
271 | * | |
272 | * Source is server: | |
273 | * parv[2] = hopcount | |
274 | * parv[3] = timestamp | |
275 | * parv[4] = username | |
276 | * parv[5] = hostname | |
277 | * parv[6] = umode (optional) | |
278 | * parv[parc-3] = IP# <- Only Protocol >= 10 | |
279 | * parv[parc-2] = YXX, numeric nick <- Only Protocol >= 10 | |
280 | * parv[parc-1] = info | |
281 | * parv[0] = server | |
282 | */ | |
283 | int ms_nick(struct Client* cptr, struct Client* sptr, int parc, char* parv[]) | |
284 | { | |
285 | struct Client *acptr; | |
286 | char nick[NICKLEN + 2]; | |
287 | time_t lastnick = 0; | |
288 | int differ = 1; | |
289 | const char *type; | |
290 | ||
291 | assert(0 != cptr); | |
292 | assert(0 != sptr); | |
293 | assert(IsServer(cptr)); | |
294 | ||
295 | if ((IsServer(sptr) && parc < 8) || parc < 3) | |
296 | { | |
297 | sendto_opmask_butone(0, SNO_OLDSNO, "bad NICK param count for %s from %C", | |
298 | parv[1], cptr); | |
299 | return need_more_params(sptr, "NICK"); | |
300 | } | |
301 | ||
302 | ircd_strncpy(nick, parv[1], NICKLEN); | |
303 | nick[NICKLEN] = '\0'; | |
304 | ||
305 | if (IsServer(sptr)) | |
306 | { | |
307 | lastnick = atoi(parv[3]); | |
308 | if (lastnick > OLDEST_TS && !IsBurstOrBurstAck(sptr)) | |
309 | cli_serv(sptr)->lag = TStime() - lastnick; | |
310 | } | |
311 | else | |
312 | { | |
313 | lastnick = atoi(parv[2]); | |
314 | if (lastnick > OLDEST_TS && !IsBurstOrBurstAck(sptr)) | |
315 | cli_serv(cli_user(sptr)->server)->lag = TStime() - lastnick; | |
316 | } | |
317 | /* | |
318 | * If do_nick_name() returns a null name OR if the server sent a nick | |
319 | * name and do_nick_name() changed it in some way (due to rules of nick | |
320 | * creation) then reject it. If from a server and we reject it, | |
321 | * and KILL it. -avalon 4/4/92 | |
322 | */ | |
323 | if (!do_nick_name(nick) || strcmp(nick, parv[1])) | |
324 | { | |
325 | send_reply(sptr, ERR_ERRONEUSNICKNAME, parv[1]); | |
326 | ||
327 | ++ServerStats->is_kill; | |
328 | sendto_opmask_butone(0, SNO_OLDSNO, "Bad Nick: %s From: %s %C", parv[1], | |
329 | parv[0], cptr); | |
330 | sendcmdto_one(&me, CMD_KILL, cptr, "%s :%s (%s <- %s[%s])", | |
331 | IsServer(sptr) ? parv[parc - 2] : parv[0], cli_name(&me), parv[1], | |
332 | nick, cli_name(cptr)); | |
333 | if (!IsServer(sptr)) | |
334 | { | |
335 | /* | |
336 | * bad nick _change_ | |
337 | */ | |
338 | sendcmdto_serv_butone(&me, CMD_KILL, 0, "%s :%s (%s <- %s!%s@%s)", | |
339 | parv[0], cli_name(&me), cli_name(cptr), parv[0], | |
340 | cli_user(sptr) ? cli_username(sptr) : "", | |
341 | cli_user(sptr) ? cli_name(cli_user(sptr)->server) : | |
342 | cli_name(cptr)); | |
343 | } | |
344 | return 0; | |
345 | } | |
346 | /* Check against nick name collisions. */ | |
347 | if ((acptr = FindClient(nick)) == NULL) | |
348 | /* No collisions, all clear... */ | |
349 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
350 | ||
351 | /* | |
352 | * If acptr == sptr, then we have a client doing a nick | |
353 | * change between *equivalent* nicknames as far as server | |
354 | * is concerned (user is changing the case of his/her | |
355 | * nickname or somesuch) | |
356 | */ | |
357 | if (acptr == sptr) | |
358 | { | |
359 | if (strcmp(cli_name(acptr), nick) != 0) | |
360 | /* Allows change of case in his/her nick */ | |
361 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
362 | else | |
363 | /* Setting their nick to what it already is? Ignore it. */ | |
364 | return 0; | |
365 | } | |
366 | /* now we know we have a real collision. */ | |
367 | /* | |
368 | * Note: From this point forward it can be assumed that | |
369 | * acptr != sptr (point to different client structures). | |
370 | */ | |
371 | assert(acptr != sptr); | |
372 | /* | |
373 | * If the older one is "non-person", the new entry is just | |
374 | * allowed to overwrite it. Just silently drop non-person, | |
375 | * and proceed with the nick. This should take care of the | |
376 | * "dormant nick" way of generating collisions... | |
377 | */ | |
378 | if (IsUnknown(acptr) && MyConnect(acptr)) | |
379 | { | |
380 | ServerStats->is_ref++; | |
381 | IPcheck_connect_fail(acptr); | |
382 | exit_client(cptr, acptr, &me, "Overridden by other sign on"); | |
383 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
384 | } | |
385 | /* | |
386 | * Decide, we really have a nick collision and deal with it | |
387 | */ | |
388 | /* | |
389 | * NICK was coming from a server connection. | |
390 | * This means we have a race condition (two users signing on | |
391 | * at the same time), or two net fragments reconnecting with the same nick. | |
392 | * The latter can happen because two different users connected | |
393 | * or because one and the same user switched server during a net break. | |
394 | * If the TimeStamps are equal, we kill both (or only 'new' | |
395 | * if it was a ":server NICK new ..."). | |
396 | * Otherwise we kill the youngest when user@host differ, | |
397 | * or the oldest when they are the same. | |
398 | * We treat user and ~user as different, because if it wasn't | |
399 | * a faked ~user the AUTH wouldn't have added the '~'. | |
400 | * --Run | |
401 | * | |
402 | */ | |
403 | if (IsServer(sptr)) | |
404 | { | |
405 | struct irc_in_addr ip; | |
406 | /* | |
407 | * A new NICK being introduced by a neighbouring | |
408 | * server (e.g. message type ":server NICK new ..." received) | |
409 | * | |
410 | * compare IP address and username | |
411 | */ | |
412 | base64toip(parv[parc - 3], &ip); | |
413 | differ = (0 != memcmp(&cli_ip(acptr), &ip, sizeof(cli_ip(acptr)))) || | |
414 | (0 != ircd_strcmp(cli_user(acptr)->username, parv[4])); | |
415 | sendto_opmask_butone(0, SNO_OLDSNO, "Nick collision on %C (%C %Tu <- " | |
416 | "%C %Tu (%s user@host))", acptr, cli_from(acptr), | |
417 | cli_lastnick(acptr), cptr, lastnick, | |
418 | differ ? "Different" : "Same"); | |
419 | } | |
420 | else | |
421 | { | |
422 | /* | |
423 | * A NICK change has collided (e.g. message type ":old NICK new"). | |
424 | * | |
425 | * compare IP address and username | |
426 | */ | |
427 | differ = (0 != memcmp(&cli_ip(acptr), &cli_ip(sptr), sizeof(cli_ip(acptr)))) || | |
428 | (0 != ircd_strcmp(cli_user(acptr)->username, cli_user(sptr)->username)); | |
429 | sendto_opmask_butone(0, SNO_OLDSNO, "Nick change collision from %C to " | |
430 | "%C (%C %Tu <- %C %Tu)", sptr, acptr, cli_from(acptr), | |
431 | cli_lastnick(acptr), cptr, lastnick); | |
432 | } | |
433 | type = differ ? "older nick overruled" : "nick collision from same user@host"; | |
434 | /* | |
435 | * Now remove (kill) the nick on our side if it is the youngest. | |
436 | * If no timestamp was received, we ignore the incoming nick | |
437 | * (and expect a KILL for our legit nick soon ): | |
438 | * When the timestamps are equal we kill both nicks. --Run | |
439 | * acptr->from != cptr should *always* be true (?). | |
440 | * | |
441 | * This exits the client sending the NICK message | |
442 | */ | |
443 | if ((differ && lastnick >= cli_lastnick(acptr)) || | |
444 | (!differ && lastnick <= cli_lastnick(acptr))) | |
445 | { | |
446 | /* We need to bounce this kill straight back... Although the nick message | |
447 | * for acptr is probably waiting in their recvq from me, its also possible | |
448 | * that sptr will change their nick on cptr before cptr receives the | |
449 | * nick message for acptr, which would leave acptr and sptr both alive | |
450 | * on cptr, but only acptr alive on me, i.e. desync. This extra kill | |
451 | * message has been absent for a while in ircu although it was a major | |
452 | * problem when it was tried on efnet, so I don't know how big an issue it | |
453 | * is. Probably best that this be left here, anyway... | |
454 | */ | |
455 | ServerStats->is_kill++; | |
456 | sendcmdto_one(&me, CMD_KILL, cptr, "%s :%s (%s)", | |
457 | nick, cli_name(&me), type); | |
458 | /* But if this was a nick change and not a nick introduction, | |
459 | * we also need to ensure that we remove our local state | |
460 | * record of the original client... Also, the rest of the | |
461 | * net should be informed... | |
462 | */ | |
463 | if (!IsServer(sptr)) | |
464 | { | |
465 | assert(!MyConnect(sptr)); | |
466 | /* Inform the rest of the net... */ | |
467 | sendcmdto_serv_butone(&me, CMD_KILL, cptr, "%s :%s (%s)", | |
468 | nick, cli_name(&me), type); | |
469 | /* Don't go sending off a QUIT message... */ | |
470 | SetFlag(sptr, FLAG_KILLED); | |
471 | /* Remove them locally. */ | |
472 | exit_client_msg(cptr, sptr, &me, | |
473 | "Killed (%s (%s))", | |
474 | feature_str(FEAT_HIS_SERVERNAME), type); | |
475 | /* | |
476 | * We have killed sptr off, zero out it's pointer so if it's used | |
477 | * again we'll know about it --Bleep | |
478 | */ | |
479 | sptr = NULL; | |
480 | } | |
481 | /* If the timestamps differ and we just killed sptr, we don't need to kill | |
482 | * acptr as well. | |
483 | */ | |
484 | if (lastnick != cli_lastnick(acptr)) | |
485 | return 0; | |
486 | } | |
487 | /* Tell acptr why we are killing it. */ | |
488 | send_reply(acptr, ERR_NICKCOLLISION, nick); | |
489 | ||
490 | ServerStats->is_kill++; | |
491 | SetFlag(acptr, FLAG_KILLED); | |
492 | /* | |
493 | * This exits the client we had before getting the NICK message | |
494 | */ | |
495 | sendcmdto_serv_butone(&me, CMD_KILL, NULL, "%C :%s" | |
496 | " (%s)", acptr, feature_str(FEAT_HIS_SERVERNAME), | |
497 | type); | |
498 | exit_client_msg(cptr, acptr, &me, "Killed (%s (%s))", | |
499 | feature_str(FEAT_HIS_SERVERNAME), type); | |
500 | if (lastnick == cli_lastnick(acptr)) | |
501 | return 0; | |
502 | if (sptr == NULL) | |
503 | return 0; | |
504 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
505 | } |