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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 | * | |
1e2f22ff | 23 | * $Id: m_nick.c,v 1.25.2.2 2006/11/04 21:42:00 entrope Exp $ |
189935b1 | 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" | |
d8e74551 | 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 | ||
1e2f22ff | 155 | if (IsServerPort(cptr)) |
156 | return exit_client(cptr, cptr, &me, "Use a different port"); | |
157 | ||
189935b1 | 158 | /* |
159 | * parv[0] will be empty for clients connecting for the first time | |
160 | */ | |
161 | client_name = (*(cli_name(sptr))) ? cli_name(sptr) : "*"; | |
162 | ||
163 | if (parc < 2) { | |
164 | send_reply(sptr, ERR_NONICKNAMEGIVEN); | |
165 | return 0; | |
166 | } | |
1e2f22ff | 167 | |
189935b1 | 168 | /* |
169 | * Don't let them send make us send back a really long string of | |
170 | * garbage | |
171 | */ | |
172 | arg = parv[1]; | |
173 | if (strlen(arg) > IRCD_MIN(NICKLEN, feature_int(FEAT_NICKLEN))) | |
174 | arg[IRCD_MIN(NICKLEN, feature_int(FEAT_NICKLEN))] = '\0'; | |
175 | ||
176 | if ((s = strchr(arg, '~'))) | |
177 | *s = '\0'; | |
178 | ||
179 | strcpy(nick, arg); | |
180 | ||
181 | /* | |
182 | * If do_nick_name() returns a null name then reject it. | |
183 | */ | |
184 | if (0 == do_nick_name(nick)) { | |
185 | send_reply(sptr, ERR_ERRONEUSNICKNAME, arg); | |
186 | return 0; | |
187 | } | |
188 | ||
d8e74551 | 189 | if (IsRegistered(sptr) && !IsAnOper(sptr) && IsNickGlined(sptr, nick)) { |
190 | send_reply(sptr, ERR_ERRONEUSNICKNAME, nick); | |
191 | return 0; | |
192 | } | |
193 | ||
189935b1 | 194 | /* |
195 | * Check if this is a LOCAL user trying to use a reserved (Juped) | |
196 | * nick, if so tell him that it's a nick in use... | |
197 | */ | |
198 | if (isNickJuped(nick)) { | |
199 | send_reply(sptr, ERR_NICKNAMEINUSE, nick); | |
200 | return 0; /* NICK message ignored */ | |
201 | } | |
202 | ||
203 | if (!(acptr = FindClient(nick))) { | |
204 | /* | |
205 | * No collisions, all clear... | |
206 | */ | |
207 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
208 | } | |
209 | if (IsServer(acptr)) { | |
210 | send_reply(sptr, ERR_NICKNAMEINUSE, nick); | |
211 | return 0; /* NICK message ignored */ | |
212 | } | |
213 | /* | |
214 | * If acptr == sptr, then we have a client doing a nick | |
215 | * change between *equivalent* nicknames as far as server | |
216 | * is concerned (user is changing the case of his/her | |
217 | * nickname or somesuch) | |
218 | */ | |
219 | if (acptr == sptr) { | |
220 | /* | |
221 | * If acptr == sptr, then we have a client doing a nick | |
222 | * change between *equivalent* nicknames as far as server | |
223 | * is concerned (user is changing the case of his/her | |
224 | * nickname or somesuch) | |
225 | */ | |
226 | if (0 != strcmp(cli_name(acptr), nick)) { | |
227 | /* | |
228 | * Allows change of case in his/her nick | |
229 | */ | |
230 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
231 | } | |
232 | /* | |
233 | * This is just ':old NICK old' type thing. | |
234 | * Just forget the whole thing here. There is | |
235 | * no point forwarding it to anywhere, | |
236 | * especially since servers prior to this | |
237 | * version would treat it as nick collision. | |
238 | */ | |
239 | return 0; | |
240 | } | |
241 | /* | |
242 | * Note: From this point forward it can be assumed that | |
243 | * acptr != sptr (point to different client structures). | |
244 | */ | |
245 | assert(acptr != sptr); | |
246 | /* | |
247 | * If the older one is "non-person", the new entry is just | |
248 | * allowed to overwrite it. Just silently drop non-person, | |
249 | * and proceed with the nick. This should take care of the | |
250 | * "dormant nick" way of generating collisions... | |
251 | * | |
252 | * XXX - hmmm can this happen after one is registered? | |
253 | * | |
254 | * Yes, client 1 connects to IRC and registers, client 2 connects and | |
255 | * sends "NICK foo" but doesn't send anything more. client 1 now does | |
256 | * /nick foo, they should succeed and client 2 gets disconnected with | |
257 | * the message below. | |
258 | */ | |
259 | if (IsUnknown(acptr) && MyConnect(acptr)) { | |
260 | ServerStats->is_ref++; | |
261 | IPcheck_connect_fail(acptr); | |
262 | exit_client(cptr, acptr, &me, "Overridden by other sign on"); | |
263 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
264 | } | |
265 | /* | |
266 | * NICK is coming from local client connection. Just | |
267 | * send error reply and ignore the command. | |
268 | */ | |
269 | send_reply(sptr, ERR_NICKNAMEINUSE, nick); | |
270 | return 0; /* NICK message ignored */ | |
271 | } | |
272 | ||
273 | ||
274 | /* | |
275 | * ms_nick - server message handler for nicks | |
276 | * parv[0] = sender prefix | |
277 | * parv[1] = nickname | |
278 | * | |
279 | * If from server, source is client: | |
280 | * parv[2] = timestamp | |
281 | * | |
282 | * Source is server: | |
283 | * parv[2] = hopcount | |
284 | * parv[3] = timestamp | |
285 | * parv[4] = username | |
286 | * parv[5] = hostname | |
287 | * parv[6] = umode (optional) | |
288 | * parv[parc-3] = IP# <- Only Protocol >= 10 | |
289 | * parv[parc-2] = YXX, numeric nick <- Only Protocol >= 10 | |
290 | * parv[parc-1] = info | |
291 | * parv[0] = server | |
292 | */ | |
293 | int ms_nick(struct Client* cptr, struct Client* sptr, int parc, char* parv[]) | |
294 | { | |
295 | struct Client *acptr; | |
296 | char nick[NICKLEN + 2]; | |
297 | time_t lastnick = 0; | |
298 | int differ = 1; | |
299 | const char *type; | |
300 | ||
301 | assert(0 != cptr); | |
302 | assert(0 != sptr); | |
303 | assert(IsServer(cptr)); | |
304 | ||
305 | if ((IsServer(sptr) && parc < 8) || parc < 3) | |
306 | { | |
307 | sendto_opmask_butone(0, SNO_OLDSNO, "bad NICK param count for %s from %C", | |
308 | parv[1], cptr); | |
309 | return need_more_params(sptr, "NICK"); | |
310 | } | |
311 | ||
312 | ircd_strncpy(nick, parv[1], NICKLEN); | |
313 | nick[NICKLEN] = '\0'; | |
314 | ||
315 | if (IsServer(sptr)) | |
316 | { | |
317 | lastnick = atoi(parv[3]); | |
318 | if (lastnick > OLDEST_TS && !IsBurstOrBurstAck(sptr)) | |
319 | cli_serv(sptr)->lag = TStime() - lastnick; | |
320 | } | |
321 | else | |
322 | { | |
323 | lastnick = atoi(parv[2]); | |
324 | if (lastnick > OLDEST_TS && !IsBurstOrBurstAck(sptr)) | |
325 | cli_serv(cli_user(sptr)->server)->lag = TStime() - lastnick; | |
326 | } | |
327 | /* | |
328 | * If do_nick_name() returns a null name OR if the server sent a nick | |
329 | * name and do_nick_name() changed it in some way (due to rules of nick | |
330 | * creation) then reject it. If from a server and we reject it, | |
331 | * and KILL it. -avalon 4/4/92 | |
332 | */ | |
333 | if (!do_nick_name(nick) || strcmp(nick, parv[1])) | |
334 | { | |
335 | send_reply(sptr, ERR_ERRONEUSNICKNAME, parv[1]); | |
336 | ||
337 | ++ServerStats->is_kill; | |
338 | sendto_opmask_butone(0, SNO_OLDSNO, "Bad Nick: %s From: %s %C", parv[1], | |
339 | parv[0], cptr); | |
340 | sendcmdto_one(&me, CMD_KILL, cptr, "%s :%s (%s <- %s[%s])", | |
341 | IsServer(sptr) ? parv[parc - 2] : parv[0], cli_name(&me), parv[1], | |
342 | nick, cli_name(cptr)); | |
343 | if (!IsServer(sptr)) | |
344 | { | |
345 | /* | |
346 | * bad nick _change_ | |
347 | */ | |
348 | sendcmdto_serv_butone(&me, CMD_KILL, 0, "%s :%s (%s <- %s!%s@%s)", | |
349 | parv[0], cli_name(&me), cli_name(cptr), parv[0], | |
350 | cli_user(sptr) ? cli_username(sptr) : "", | |
351 | cli_user(sptr) ? cli_name(cli_user(sptr)->server) : | |
352 | cli_name(cptr)); | |
353 | } | |
354 | return 0; | |
355 | } | |
356 | /* Check against nick name collisions. */ | |
357 | if ((acptr = FindClient(nick)) == NULL) | |
358 | /* No collisions, all clear... */ | |
359 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
360 | ||
361 | /* | |
362 | * If acptr == sptr, then we have a client doing a nick | |
363 | * change between *equivalent* nicknames as far as server | |
364 | * is concerned (user is changing the case of his/her | |
365 | * nickname or somesuch) | |
366 | */ | |
367 | if (acptr == sptr) | |
368 | { | |
369 | if (strcmp(cli_name(acptr), nick) != 0) | |
370 | /* Allows change of case in his/her nick */ | |
371 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
372 | else | |
373 | /* Setting their nick to what it already is? Ignore it. */ | |
374 | return 0; | |
375 | } | |
376 | /* now we know we have a real collision. */ | |
377 | /* | |
378 | * Note: From this point forward it can be assumed that | |
379 | * acptr != sptr (point to different client structures). | |
380 | */ | |
381 | assert(acptr != sptr); | |
382 | /* | |
383 | * If the older one is "non-person", the new entry is just | |
384 | * allowed to overwrite it. Just silently drop non-person, | |
385 | * and proceed with the nick. This should take care of the | |
386 | * "dormant nick" way of generating collisions... | |
387 | */ | |
388 | if (IsUnknown(acptr) && MyConnect(acptr)) | |
389 | { | |
390 | ServerStats->is_ref++; | |
391 | IPcheck_connect_fail(acptr); | |
392 | exit_client(cptr, acptr, &me, "Overridden by other sign on"); | |
393 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
394 | } | |
395 | /* | |
396 | * Decide, we really have a nick collision and deal with it | |
397 | */ | |
398 | /* | |
399 | * NICK was coming from a server connection. | |
400 | * This means we have a race condition (two users signing on | |
401 | * at the same time), or two net fragments reconnecting with the same nick. | |
402 | * The latter can happen because two different users connected | |
403 | * or because one and the same user switched server during a net break. | |
404 | * If the TimeStamps are equal, we kill both (or only 'new' | |
405 | * if it was a ":server NICK new ..."). | |
406 | * Otherwise we kill the youngest when user@host differ, | |
407 | * or the oldest when they are the same. | |
408 | * We treat user and ~user as different, because if it wasn't | |
409 | * a faked ~user the AUTH wouldn't have added the '~'. | |
410 | * --Run | |
411 | * | |
412 | */ | |
413 | if (IsServer(sptr)) | |
414 | { | |
415 | struct irc_in_addr ip; | |
416 | /* | |
417 | * A new NICK being introduced by a neighbouring | |
418 | * server (e.g. message type ":server NICK new ..." received) | |
419 | * | |
420 | * compare IP address and username | |
421 | */ | |
422 | base64toip(parv[parc - 3], &ip); | |
423 | differ = (0 != memcmp(&cli_ip(acptr), &ip, sizeof(cli_ip(acptr)))) || | |
424 | (0 != ircd_strcmp(cli_user(acptr)->username, parv[4])); | |
425 | sendto_opmask_butone(0, SNO_OLDSNO, "Nick collision on %C (%C %Tu <- " | |
426 | "%C %Tu (%s user@host))", acptr, cli_from(acptr), | |
427 | cli_lastnick(acptr), cptr, lastnick, | |
428 | differ ? "Different" : "Same"); | |
429 | } | |
430 | else | |
431 | { | |
432 | /* | |
433 | * A NICK change has collided (e.g. message type ":old NICK new"). | |
434 | * | |
435 | * compare IP address and username | |
436 | */ | |
437 | differ = (0 != memcmp(&cli_ip(acptr), &cli_ip(sptr), sizeof(cli_ip(acptr)))) || | |
438 | (0 != ircd_strcmp(cli_user(acptr)->username, cli_user(sptr)->username)); | |
439 | sendto_opmask_butone(0, SNO_OLDSNO, "Nick change collision from %C to " | |
440 | "%C (%C %Tu <- %C %Tu)", sptr, acptr, cli_from(acptr), | |
441 | cli_lastnick(acptr), cptr, lastnick); | |
442 | } | |
052b069e | 443 | type = differ ? "overruled by older nick" : "nick collision from same user@host"; |
189935b1 | 444 | /* |
445 | * Now remove (kill) the nick on our side if it is the youngest. | |
446 | * If no timestamp was received, we ignore the incoming nick | |
447 | * (and expect a KILL for our legit nick soon ): | |
448 | * When the timestamps are equal we kill both nicks. --Run | |
449 | * acptr->from != cptr should *always* be true (?). | |
450 | * | |
451 | * This exits the client sending the NICK message | |
452 | */ | |
453 | if ((differ && lastnick >= cli_lastnick(acptr)) || | |
454 | (!differ && lastnick <= cli_lastnick(acptr))) | |
455 | { | |
189935b1 | 456 | ServerStats->is_kill++; |
189935b1 | 457 | if (!IsServer(sptr)) |
458 | { | |
052b069e | 459 | /* If this was a nick change and not a nick introduction, we |
460 | * need to ensure that we remove our record of the client, and | |
461 | * send a KILL to the whole network. | |
462 | */ | |
189935b1 | 463 | assert(!MyConnect(sptr)); |
464 | /* Inform the rest of the net... */ | |
052b069e | 465 | sendcmdto_serv_butone(&me, CMD_KILL, 0, "%C :%s (%s)", |
466 | sptr, cli_name(&me), type); | |
189935b1 | 467 | /* Don't go sending off a QUIT message... */ |
468 | SetFlag(sptr, FLAG_KILLED); | |
469 | /* Remove them locally. */ | |
470 | exit_client_msg(cptr, sptr, &me, | |
471 | "Killed (%s (%s))", | |
472 | feature_str(FEAT_HIS_SERVERNAME), type); | |
052b069e | 473 | } |
474 | else | |
475 | { | |
476 | /* If the origin is a server, this was a new client, so we only | |
477 | * send the KILL in the direction it came from. We have no | |
478 | * client record that we would have to clean up. | |
189935b1 | 479 | */ |
052b069e | 480 | sendcmdto_one(&me, CMD_KILL, cptr, "%s :%s (%s)", |
481 | parv[parc - 2], cli_name(&me), type); | |
189935b1 | 482 | } |
483 | /* If the timestamps differ and we just killed sptr, we don't need to kill | |
484 | * acptr as well. | |
485 | */ | |
486 | if (lastnick != cli_lastnick(acptr)) | |
487 | return 0; | |
488 | } | |
489 | /* Tell acptr why we are killing it. */ | |
490 | send_reply(acptr, ERR_NICKCOLLISION, nick); | |
491 | ||
492 | ServerStats->is_kill++; | |
493 | SetFlag(acptr, FLAG_KILLED); | |
494 | /* | |
495 | * This exits the client we had before getting the NICK message | |
496 | */ | |
052b069e | 497 | sendcmdto_serv_butone(&me, CMD_KILL, NULL, "%C :%s (%s)", |
498 | acptr, feature_str(FEAT_HIS_SERVERNAME), | |
189935b1 | 499 | type); |
500 | exit_client_msg(cptr, acptr, &me, "Killed (%s (%s))", | |
501 | feature_str(FEAT_HIS_SERVERNAME), type); | |
502 | if (lastnick == cli_lastnick(acptr)) | |
503 | return 0; | |
504 | if (sptr == NULL) | |
505 | return 0; | |
506 | return set_nick_name(cptr, sptr, nick, parc, parv); | |
507 | } |