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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" | |
98de26a3 | 101 | #include "gline.h" |
189935b1 | 102 | |
103 | /* #include <assert.h> -- Now using assert in ircd_log.h */ | |
104 | #include <stdlib.h> | |
105 | #include <string.h> | |
106 | ||
107 | /* | |
108 | * 'do_nick_name' ensures that the given parameter (nick) is really a proper | |
109 | * string for a nickname (note, the 'nick' may be modified in the process...) | |
110 | * | |
111 | * RETURNS the length of the final NICKNAME (0, if nickname is invalid) | |
112 | * | |
113 | * Nickname characters are in range 'A'..'}', '_', '-', '0'..'9' | |
114 | * anything outside the above set will terminate nickname. | |
115 | * In addition, the first character cannot be '-' or a Digit. | |
116 | * | |
117 | * Note: | |
118 | * The '~'-character should be allowed, but a change should be global, | |
119 | * some confusion would result if only few servers allowed it... | |
120 | */ | |
121 | static int do_nick_name(char* nick) | |
122 | { | |
123 | char* ch = nick; | |
124 | char* end = ch + NICKLEN; | |
125 | assert(0 != ch); | |
126 | ||
127 | /* first character in [0..9-] */ | |
128 | if (*ch == '-' || IsDigit(*ch)) | |
129 | return 0; | |
130 | for ( ; (ch < end) && *ch; ++ch) | |
131 | if (!IsNickChar(*ch)) | |
132 | break; | |
133 | ||
134 | *ch = '\0'; | |
135 | ||
136 | return (ch - nick); | |
137 | } | |
138 | ||
139 | /* | |
140 | * m_nick - message handler for local clients | |
141 | * parv[0] = sender prefix | |
142 | * parv[1] = nickname | |
143 | */ | |
144 | int m_nick(struct Client* cptr, struct Client* sptr, int parc, char* parv[]) | |
145 | { | |
146 | struct Client* acptr; | |
147 | char nick[NICKLEN + 2]; | |
148 | char* arg; | |
149 | char* s; | |
150 | const char* client_name; | |
151 | ||
152 | assert(0 != cptr); | |
153 | assert(cptr == sptr); | |
154 | ||
155 | /* | |
156 | * parv[0] will be empty for clients connecting for the first time | |
157 | */ | |
158 | client_name = (*(cli_name(sptr))) ? cli_name(sptr) : "*"; | |
159 | ||
160 | if (parc < 2) { | |
161 | send_reply(sptr, ERR_NONICKNAMEGIVEN); | |
162 | return 0; | |
163 | } | |
164 | /* | |
165 | * Don't let them send make us send back a really long string of | |
166 | * garbage | |
167 | */ | |
168 | arg = parv[1]; | |
169 | if (strlen(arg) > IRCD_MIN(NICKLEN, feature_int(FEAT_NICKLEN))) | |
170 | arg[IRCD_MIN(NICKLEN, feature_int(FEAT_NICKLEN))] = '\0'; | |
171 | ||
172 | if ((s = strchr(arg, '~'))) | |
173 | *s = '\0'; | |
174 | ||
175 | strcpy(nick, arg); | |
176 | ||
177 | /* | |
178 | * If do_nick_name() returns a null name then reject it. | |
179 | */ | |
180 | if (0 == do_nick_name(nick)) { | |
181 | send_reply(sptr, ERR_ERRONEUSNICKNAME, arg); | |
182 | return 0; | |
183 | } | |
184 | ||
98de26a3 | 185 | if (IsRegistered(sptr) && !IsAnOper(sptr) && IsNickGlined(sptr, nick)) { |
186 | send_reply(sptr, ERR_ERRONEUSNICKNAME, nick); | |
187 | return 0; | |
188 | } | |
189 | ||
189935b1 | 190 | /* |
191 | * Check if this is a LOCAL user trying to use a reserved (Juped) | |
192 | * nick, if so tell him that it's a nick in use... | |
193 | */ | |
194 | if (isNickJuped(nick)) { | |
195 | send_reply(sptr, ERR_NICKNAMEINUSE, nick); | |
196 | return 0; /* NICK message ignored */ | |
197 | } | |
198 | ||
199 | if (!(acptr = FindClient(nick))) { | |
200 | /* | |
201 | * No collisions, all clear... | |
202 | */ | |
203 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
204 | } | |
205 | if (IsServer(acptr)) { | |
206 | send_reply(sptr, ERR_NICKNAMEINUSE, nick); | |
207 | return 0; /* NICK message ignored */ | |
208 | } | |
209 | /* | |
210 | * If acptr == sptr, then we have a client doing a nick | |
211 | * change between *equivalent* nicknames as far as server | |
212 | * is concerned (user is changing the case of his/her | |
213 | * nickname or somesuch) | |
214 | */ | |
215 | if (acptr == sptr) { | |
216 | /* | |
217 | * If acptr == sptr, then we have a client doing a nick | |
218 | * change between *equivalent* nicknames as far as server | |
219 | * is concerned (user is changing the case of his/her | |
220 | * nickname or somesuch) | |
221 | */ | |
222 | if (0 != strcmp(cli_name(acptr), nick)) { | |
223 | /* | |
224 | * Allows change of case in his/her nick | |
225 | */ | |
226 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
227 | } | |
228 | /* | |
229 | * This is just ':old NICK old' type thing. | |
230 | * Just forget the whole thing here. There is | |
231 | * no point forwarding it to anywhere, | |
232 | * especially since servers prior to this | |
233 | * version would treat it as nick collision. | |
234 | */ | |
235 | return 0; | |
236 | } | |
237 | /* | |
238 | * Note: From this point forward it can be assumed that | |
239 | * acptr != sptr (point to different client structures). | |
240 | */ | |
241 | assert(acptr != sptr); | |
242 | /* | |
243 | * If the older one is "non-person", the new entry is just | |
244 | * allowed to overwrite it. Just silently drop non-person, | |
245 | * and proceed with the nick. This should take care of the | |
246 | * "dormant nick" way of generating collisions... | |
247 | * | |
248 | * XXX - hmmm can this happen after one is registered? | |
249 | * | |
250 | * Yes, client 1 connects to IRC and registers, client 2 connects and | |
251 | * sends "NICK foo" but doesn't send anything more. client 1 now does | |
252 | * /nick foo, they should succeed and client 2 gets disconnected with | |
253 | * the message below. | |
254 | */ | |
255 | if (IsUnknown(acptr) && MyConnect(acptr)) { | |
256 | ServerStats->is_ref++; | |
257 | IPcheck_connect_fail(acptr); | |
258 | exit_client(cptr, acptr, &me, "Overridden by other sign on"); | |
259 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
260 | } | |
261 | /* | |
262 | * NICK is coming from local client connection. Just | |
263 | * send error reply and ignore the command. | |
264 | */ | |
265 | send_reply(sptr, ERR_NICKNAMEINUSE, nick); | |
266 | return 0; /* NICK message ignored */ | |
267 | } | |
268 | ||
269 | ||
270 | /* | |
271 | * ms_nick - server message handler for nicks | |
272 | * parv[0] = sender prefix | |
273 | * parv[1] = nickname | |
274 | * | |
275 | * If from server, source is client: | |
276 | * parv[2] = timestamp | |
277 | * | |
278 | * Source is server: | |
279 | * parv[2] = hopcount | |
280 | * parv[3] = timestamp | |
281 | * parv[4] = username | |
282 | * parv[5] = hostname | |
283 | * parv[6] = umode (optional) | |
284 | * parv[parc-3] = IP# <- Only Protocol >= 10 | |
285 | * parv[parc-2] = YXX, numeric nick <- Only Protocol >= 10 | |
286 | * parv[parc-1] = info | |
287 | * parv[0] = server | |
288 | */ | |
289 | int ms_nick(struct Client* cptr, struct Client* sptr, int parc, char* parv[]) | |
290 | { | |
291 | struct Client *acptr; | |
292 | char nick[NICKLEN + 2]; | |
293 | time_t lastnick = 0; | |
294 | int differ = 1; | |
295 | const char *type; | |
296 | ||
297 | assert(0 != cptr); | |
298 | assert(0 != sptr); | |
299 | assert(IsServer(cptr)); | |
300 | ||
301 | if ((IsServer(sptr) && parc < 8) || parc < 3) | |
302 | { | |
303 | sendto_opmask_butone(0, SNO_OLDSNO, "bad NICK param count for %s from %C", | |
304 | parv[1], cptr); | |
305 | return need_more_params(sptr, "NICK"); | |
306 | } | |
307 | ||
308 | ircd_strncpy(nick, parv[1], NICKLEN); | |
309 | nick[NICKLEN] = '\0'; | |
310 | ||
311 | if (IsServer(sptr)) | |
312 | { | |
313 | lastnick = atoi(parv[3]); | |
314 | if (lastnick > OLDEST_TS && !IsBurstOrBurstAck(sptr)) | |
315 | cli_serv(sptr)->lag = TStime() - lastnick; | |
316 | } | |
317 | else | |
318 | { | |
319 | lastnick = atoi(parv[2]); | |
320 | if (lastnick > OLDEST_TS && !IsBurstOrBurstAck(sptr)) | |
321 | cli_serv(cli_user(sptr)->server)->lag = TStime() - lastnick; | |
322 | } | |
323 | /* | |
324 | * If do_nick_name() returns a null name OR if the server sent a nick | |
325 | * name and do_nick_name() changed it in some way (due to rules of nick | |
326 | * creation) then reject it. If from a server and we reject it, | |
327 | * and KILL it. -avalon 4/4/92 | |
328 | */ | |
329 | if (!do_nick_name(nick) || strcmp(nick, parv[1])) | |
330 | { | |
331 | send_reply(sptr, ERR_ERRONEUSNICKNAME, parv[1]); | |
332 | ||
333 | ++ServerStats->is_kill; | |
334 | sendto_opmask_butone(0, SNO_OLDSNO, "Bad Nick: %s From: %s %C", parv[1], | |
335 | parv[0], cptr); | |
336 | sendcmdto_one(&me, CMD_KILL, cptr, "%s :%s (%s <- %s[%s])", | |
337 | IsServer(sptr) ? parv[parc - 2] : parv[0], cli_name(&me), parv[1], | |
338 | nick, cli_name(cptr)); | |
339 | if (!IsServer(sptr)) | |
340 | { | |
341 | /* | |
342 | * bad nick _change_ | |
343 | */ | |
344 | sendcmdto_serv_butone(&me, CMD_KILL, 0, "%s :%s (%s <- %s!%s@%s)", | |
345 | parv[0], cli_name(&me), cli_name(cptr), parv[0], | |
346 | cli_user(sptr) ? cli_username(sptr) : "", | |
347 | cli_user(sptr) ? cli_name(cli_user(sptr)->server) : | |
348 | cli_name(cptr)); | |
349 | } | |
350 | return 0; | |
351 | } | |
352 | /* Check against nick name collisions. */ | |
353 | if ((acptr = FindClient(nick)) == NULL) | |
354 | /* No collisions, all clear... */ | |
355 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
356 | ||
357 | /* | |
358 | * If acptr == sptr, then we have a client doing a nick | |
359 | * change between *equivalent* nicknames as far as server | |
360 | * is concerned (user is changing the case of his/her | |
361 | * nickname or somesuch) | |
362 | */ | |
363 | if (acptr == sptr) | |
364 | { | |
365 | if (strcmp(cli_name(acptr), nick) != 0) | |
366 | /* Allows change of case in his/her nick */ | |
367 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
368 | else | |
369 | /* Setting their nick to what it already is? Ignore it. */ | |
370 | return 0; | |
371 | } | |
372 | /* now we know we have a real collision. */ | |
373 | /* | |
374 | * Note: From this point forward it can be assumed that | |
375 | * acptr != sptr (point to different client structures). | |
376 | */ | |
377 | assert(acptr != sptr); | |
378 | /* | |
379 | * If the older one is "non-person", the new entry is just | |
380 | * allowed to overwrite it. Just silently drop non-person, | |
381 | * and proceed with the nick. This should take care of the | |
382 | * "dormant nick" way of generating collisions... | |
383 | */ | |
384 | if (IsUnknown(acptr) && MyConnect(acptr)) | |
385 | { | |
386 | ServerStats->is_ref++; | |
387 | IPcheck_connect_fail(acptr); | |
388 | exit_client(cptr, acptr, &me, "Overridden by other sign on"); | |
389 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
390 | } | |
391 | /* | |
392 | * Decide, we really have a nick collision and deal with it | |
393 | */ | |
394 | /* | |
395 | * NICK was coming from a server connection. | |
396 | * This means we have a race condition (two users signing on | |
397 | * at the same time), or two net fragments reconnecting with the same nick. | |
398 | * The latter can happen because two different users connected | |
399 | * or because one and the same user switched server during a net break. | |
400 | * If the TimeStamps are equal, we kill both (or only 'new' | |
401 | * if it was a ":server NICK new ..."). | |
402 | * Otherwise we kill the youngest when user@host differ, | |
403 | * or the oldest when they are the same. | |
404 | * We treat user and ~user as different, because if it wasn't | |
405 | * a faked ~user the AUTH wouldn't have added the '~'. | |
406 | * --Run | |
407 | * | |
408 | */ | |
409 | if (IsServer(sptr)) | |
410 | { | |
411 | struct irc_in_addr ip; | |
412 | /* | |
413 | * A new NICK being introduced by a neighbouring | |
414 | * server (e.g. message type ":server NICK new ..." received) | |
415 | * | |
416 | * compare IP address and username | |
417 | */ | |
418 | base64toip(parv[parc - 3], &ip); | |
419 | differ = (0 != memcmp(&cli_ip(acptr), &ip, sizeof(cli_ip(acptr)))) || | |
420 | (0 != ircd_strcmp(cli_user(acptr)->username, parv[4])); | |
421 | sendto_opmask_butone(0, SNO_OLDSNO, "Nick collision on %C (%C %Tu <- " | |
422 | "%C %Tu (%s user@host))", acptr, cli_from(acptr), | |
423 | cli_lastnick(acptr), cptr, lastnick, | |
424 | differ ? "Different" : "Same"); | |
425 | } | |
426 | else | |
427 | { | |
428 | /* | |
429 | * A NICK change has collided (e.g. message type ":old NICK new"). | |
430 | * | |
431 | * compare IP address and username | |
432 | */ | |
433 | differ = (0 != memcmp(&cli_ip(acptr), &cli_ip(sptr), sizeof(cli_ip(acptr)))) || | |
434 | (0 != ircd_strcmp(cli_user(acptr)->username, cli_user(sptr)->username)); | |
435 | sendto_opmask_butone(0, SNO_OLDSNO, "Nick change collision from %C to " | |
436 | "%C (%C %Tu <- %C %Tu)", sptr, acptr, cli_from(acptr), | |
437 | cli_lastnick(acptr), cptr, lastnick); | |
438 | } | |
439 | type = differ ? "older nick overruled" : "nick collision from same user@host"; | |
440 | /* | |
441 | * Now remove (kill) the nick on our side if it is the youngest. | |
442 | * If no timestamp was received, we ignore the incoming nick | |
443 | * (and expect a KILL for our legit nick soon ): | |
444 | * When the timestamps are equal we kill both nicks. --Run | |
445 | * acptr->from != cptr should *always* be true (?). | |
446 | * | |
447 | * This exits the client sending the NICK message | |
448 | */ | |
449 | if ((differ && lastnick >= cli_lastnick(acptr)) || | |
450 | (!differ && lastnick <= cli_lastnick(acptr))) | |
451 | { | |
452 | /* We need to bounce this kill straight back... Although the nick message | |
453 | * for acptr is probably waiting in their recvq from me, its also possible | |
454 | * that sptr will change their nick on cptr before cptr receives the | |
455 | * nick message for acptr, which would leave acptr and sptr both alive | |
456 | * on cptr, but only acptr alive on me, i.e. desync. This extra kill | |
457 | * message has been absent for a while in ircu although it was a major | |
458 | * problem when it was tried on efnet, so I don't know how big an issue it | |
459 | * is. Probably best that this be left here, anyway... | |
460 | */ | |
461 | ServerStats->is_kill++; | |
462 | sendcmdto_one(&me, CMD_KILL, cptr, "%s :%s (%s)", | |
463 | nick, cli_name(&me), type); | |
464 | /* But if this was a nick change and not a nick introduction, | |
465 | * we also need to ensure that we remove our local state | |
466 | * record of the original client... Also, the rest of the | |
467 | * net should be informed... | |
468 | */ | |
469 | if (!IsServer(sptr)) | |
470 | { | |
471 | assert(!MyConnect(sptr)); | |
472 | /* Inform the rest of the net... */ | |
473 | sendcmdto_serv_butone(&me, CMD_KILL, cptr, "%s :%s (%s)", | |
474 | nick, cli_name(&me), type); | |
475 | /* Don't go sending off a QUIT message... */ | |
476 | SetFlag(sptr, FLAG_KILLED); | |
477 | /* Remove them locally. */ | |
478 | exit_client_msg(cptr, sptr, &me, | |
479 | "Killed (%s (%s))", | |
480 | feature_str(FEAT_HIS_SERVERNAME), type); | |
481 | /* | |
482 | * We have killed sptr off, zero out it's pointer so if it's used | |
483 | * again we'll know about it --Bleep | |
484 | */ | |
485 | sptr = NULL; | |
486 | } | |
487 | /* If the timestamps differ and we just killed sptr, we don't need to kill | |
488 | * acptr as well. | |
489 | */ | |
490 | if (lastnick != cli_lastnick(acptr)) | |
491 | return 0; | |
492 | } | |
493 | /* Tell acptr why we are killing it. */ | |
494 | send_reply(acptr, ERR_NICKCOLLISION, nick); | |
495 | ||
496 | ServerStats->is_kill++; | |
497 | SetFlag(acptr, FLAG_KILLED); | |
498 | /* | |
499 | * This exits the client we had before getting the NICK message | |
500 | */ | |
501 | sendcmdto_serv_butone(&me, CMD_KILL, NULL, "%C :%s" | |
502 | " (%s)", acptr, feature_str(FEAT_HIS_SERVERNAME), | |
503 | type); | |
504 | exit_client_msg(cptr, acptr, &me, "Killed (%s (%s))", | |
505 | feature_str(FEAT_HIS_SERVERNAME), type); | |
506 | if (lastnick == cli_lastnick(acptr)) | |
507 | return 0; | |
508 | if (sptr == NULL) | |
509 | return 0; | |
510 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
511 | } |