2 * IRC - Internet Relay Chat, ircd/m_nick.c
3 * Copyright (C) 1990 Jarkko Oikarinen and
4 * University of Oulu, Computing Center
6 * See file AUTHORS in IRC package for additional names of
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)
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.
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.
27 * m_functions execute protocol messages on this server:
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...).
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.
39 * (!IsServer(cptr)) => (cptr == sptr), because
40 * prefixes are taken *only* from servers...
43 * (sptr == cptr) => the message didn't
46 * (sptr != cptr && IsServer(sptr) means
47 * the prefix specified servername. (?)
49 * (sptr != cptr && !IsServer(sptr) means
50 * that message originated from a remote
55 * (!IsServer(sptr)) means that, sptr can safely
56 * taken as defining the target structure of the
57 * message in this server.
59 * *Always* true (if 'parse' and others are working correct):
61 * 1) sptr->from == cptr (note: cptr->from == cptr)
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 ]
68 * parc number of variable parameter strings (if zero,
69 * parv is allowed to be NULL)
71 * parv a NULL terminated list of parameter pointers,
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*
79 * note: it is guaranteed that parv[0]..parv[parc-1] are all
88 #include "ircd_chattr.h"
89 #include "ircd_features.h"
90 #include "ircd_reply.h"
91 #include "ircd_string.h"
105 * 'do_nick_name' ensures that the given parameter (nick) is really a proper
106 * string for a nickname (note, the 'nick' may be modified in the process...)
108 * RETURNS the length of the final NICKNAME (0, if nickname is invalid)
110 * Nickname characters are in range 'A'..'}', '_', '-', '0'..'9'
111 * anything outside the above set will terminate nickname.
112 * In addition, the first character cannot be '-' or a Digit.
115 * The '~'-character should be allowed, but a change should be global,
116 * some confusion would result if only few servers allowed it...
118 static int do_nick_name(char* nick)
121 char* end = ch + NICKLEN;
124 /* first character in [0..9-] */
125 if (*ch == '-' || IsDigit(*ch))
127 for ( ; (ch < end) && *ch; ++ch)
128 if (!IsNickChar(*ch))
137 * m_nick - message handler for local clients
138 * parv[0] = sender prefix
141 int m_nick(struct Client* cptr, struct Client* sptr, int parc, char* parv[])
143 struct Client* acptr;
144 char nick[NICKLEN + 2];
147 const char* client_name;
150 assert(cptr == sptr);
153 * parv[0] will be empty for clients connecting for the first time
155 client_name = (*(cli_name(sptr))) ? cli_name(sptr) : "*";
158 send_reply(sptr, ERR_NONICKNAMEGIVEN);
162 * Don't let them send make us send back a really long string of
166 if (strlen(arg) > NICKLEN)
169 if ((s = strchr(arg, '~')))
175 * If do_nick_name() returns a null name then reject it.
177 if (0 == do_nick_name(nick)) {
178 send_reply(sptr, ERR_ERRONEUSNICKNAME, arg);
183 * Check if this is a LOCAL user trying to use a reserved (Juped)
184 * nick, if so tell him that it's a nick in use...
186 if (isNickJuped(nick)) {
187 send_reply(sptr, ERR_NICKNAMEINUSE, nick);
188 return 0; /* NICK message ignored */
191 if (!(acptr = FindClient(nick))) {
193 * No collisions, all clear...
195 return set_nick_name(cptr, sptr, nick, parc, parv);
197 if (IsServer(acptr)) {
198 send_reply(sptr, ERR_NICKNAMEINUSE, nick);
199 return 0; /* NICK message ignored */
202 * If acptr == sptr, then we have a client doing a nick
203 * change between *equivalent* nicknames as far as server
204 * is concerned (user is changing the case of his/her
205 * nickname or somesuch)
209 * If acptr == sptr, then we have a client doing a nick
210 * change between *equivalent* nicknames as far as server
211 * is concerned (user is changing the case of his/her
212 * nickname or somesuch)
214 if (0 != strcmp(cli_name(acptr), nick)) {
216 * Allows change of case in his/her nick
218 return set_nick_name(cptr, sptr, nick, parc, parv);
221 * This is just ':old NICK old' type thing.
222 * Just forget the whole thing here. There is
223 * no point forwarding it to anywhere,
224 * especially since servers prior to this
225 * version would treat it as nick collision.
230 * Note: From this point forward it can be assumed that
231 * acptr != sptr (point to different client structures).
233 assert(acptr != sptr);
235 * If the older one is "non-person", the new entry is just
236 * allowed to overwrite it. Just silently drop non-person,
237 * and proceed with the nick. This should take care of the
238 * "dormant nick" way of generating collisions...
240 * XXX - hmmm can this happen after one is registered?
242 * Yes, client 1 connects to IRC and registers, client 2 connects and
243 * sends "NICK foo" but doesn't send anything more. client 1 now does
244 * /nick foo, they should succeed and client 2 gets disconnected with
247 if (IsUnknown(acptr) && MyConnect(acptr)) {
248 ++ServerStats->is_ref;
249 IPcheck_connect_fail(cli_ip(acptr));
250 exit_client(cptr, acptr, &me, "Overridden by other sign on");
251 return set_nick_name(cptr, sptr, nick, parc, parv);
254 * NICK is coming from local client connection. Just
255 * send error reply and ignore the command.
257 send_reply(sptr, ERR_NICKNAMEINUSE, nick);
258 return 0; /* NICK message ignored */
263 * ms_nick - server message handler for nicks
264 * parv[0] = sender prefix
267 * If from server, source is client:
268 * parv[2] = timestamp
272 * parv[3] = timestamp
275 * parv[6] = umode (optional)
276 * parv[parc-3] = IP# <- Only Protocol >= 10
277 * parv[parc-2] = YXX, numeric nick <- Only Protocol >= 10
278 * parv[parc-1] = info
281 int ms_nick(struct Client* cptr, struct Client* sptr, int parc, char* parv[])
283 struct Client *acptr;
284 char nick[NICKLEN + 2];
291 assert(IsServer(cptr));
293 if ((IsServer(sptr) && parc < 8) || parc < 3)
295 sendto_opmask_butone(0, SNO_OLDSNO, "bad NICK param count for %s from %C",
297 return need_more_params(sptr, "NICK");
300 ircd_strncpy(nick, parv[1], NICKLEN);
301 nick[NICKLEN] = '\0';
305 lastnick = atoi(parv[3]);
306 if (lastnick > OLDEST_TS && !IsBurstOrBurstAck(sptr))
307 cli_serv(sptr)->lag = TStime() - lastnick;
311 lastnick = atoi(parv[2]);
312 if (lastnick > OLDEST_TS && !IsBurstOrBurstAck(sptr))
313 cli_serv(cli_user(sptr)->server)->lag = TStime() - lastnick;
316 * If do_nick_name() returns a null name OR if the server sent a nick
317 * name and do_nick_name() changed it in some way (due to rules of nick
318 * creation) then reject it. If from a server and we reject it,
319 * and KILL it. -avalon 4/4/92
321 if (strlen(nick) != do_nick_name(nick))
323 send_reply(sptr, ERR_ERRONEUSNICKNAME, parv[1]);
325 ++ServerStats->is_kill;
326 sendto_opmask_butone(0, SNO_OLDSNO, "Bad Nick: %s From: %s %C", parv[1],
328 sendcmdto_one(&me, CMD_KILL, cptr, "%s :%s (%s <- %s[%s])",
329 IsServer(sptr) ? parv[parc - 2] : parv[0], cli_name(&me), parv[1],
330 nick, cli_name(cptr));
336 sendcmdto_serv_butone(&me, CMD_KILL, 0, "%s :%s (%s <- %s!%s@%s)",
337 parv[0], cli_name(&me), cli_name(cptr), parv[0],
338 cli_user(sptr) ? cli_username(sptr) : "",
339 cli_user(sptr) ? cli_name(cli_user(sptr)->server) :
344 /* Check against nick name collisions. */
345 if ((acptr = FindClient(nick)) == NULL)
346 /* No collisions, all clear... */
347 return set_nick_name(cptr, sptr, nick, parc, parv);
350 * If acptr == sptr, then we have a client doing a nick
351 * change between *equivalent* nicknames as far as server
352 * is concerned (user is changing the case of his/her
353 * nickname or somesuch)
357 if (strcmp(cli_name(acptr), nick) != 0)
358 /* Allows change of case in his/her nick */
359 return set_nick_name(cptr, sptr, nick, parc, parv);
361 /* Setting their nick to what it already is? Ignore it. */
364 /* now we know we have a real collision. */
366 * Note: From this point forward it can be assumed that
367 * acptr != sptr (point to different client structures).
369 assert(acptr != sptr);
371 * If the older one is "non-person", the new entry is just
372 * allowed to overwrite it. Just silently drop non-person,
373 * and proceed with the nick. This should take care of the
374 * "dormant nick" way of generating collisions...
376 if (IsUnknown(acptr) && MyConnect(acptr))
378 ServerStats->is_ref++;
379 IPcheck_connect_fail(cli_ip(acptr));
380 exit_client(cptr, acptr, &me, "Overridden by other sign on");
381 return set_nick_name(cptr, sptr, nick, parc, parv);
384 * Decide, we really have a nick collision and deal with it
387 * NICK was coming from a server connection.
388 * This means we have a race condition (two users signing on
389 * at the same time), or two net fragments reconnecting with the same nick.
390 * The latter can happen because two different users connected
391 * or because one and the same user switched server during a net break.
392 * If the TimeStamps are equal, we kill both (or only 'new'
393 * if it was a ":server NICK new ...").
394 * Otherwise we kill the youngest when user@host differ,
395 * or the oldest when they are the same.
396 * We treat user and ~user as different, because if it wasn't
397 * a faked ~user the AUTH wouldn't have added the '~'.
404 * A new NICK being introduced by a neighbouring
405 * server (e.g. message type ":server NICK new ..." received)
407 * compare IP address and username
409 differ = (cli_ip(acptr).s_addr != htonl(base64toint(parv[parc - 3]))) ||
410 (0 != ircd_strcmp(cli_user(acptr)->username, parv[4]));
411 sendto_opmask_butone(0, SNO_OLDSNO, "Nick collision on %C (%C %Tu <- "
412 "%C %Tu (%s user@host))", acptr, cli_from(acptr),
413 cli_lastnick(acptr), cptr, lastnick,
414 differ ? "Different" : "Same");
419 * A NICK change has collided (e.g. message type ":old NICK new").
421 * compare IP address and username
423 differ = (cli_ip(acptr).s_addr != cli_ip(sptr).s_addr) ||
424 (0 != ircd_strcmp(cli_user(acptr)->username, cli_user(sptr)->username));
425 sendto_opmask_butone(0, SNO_OLDSNO, "Nick change collision from %C to "
426 "%C (%C %Tu <- %C %Tu)", sptr, acptr, cli_from(acptr),
427 cli_lastnick(acptr), cptr, lastnick);
429 type = differ ? "older nick overruled" : "nick collision from same user@host";
431 * Now remove (kill) the nick on our side if it is the youngest.
432 * If no timestamp was received, we ignore the incoming nick
433 * (and expect a KILL for our legit nick soon ):
434 * When the timestamps are equal we kill both nicks. --Run
435 * acptr->from != cptr should *always* be true (?).
437 * This exits the client sending the NICK message
439 if ((differ && lastnick >= cli_lastnick(acptr)) ||
440 (!differ && lastnick <= cli_lastnick(acptr)))
442 /* We need to bounce this kill straight back... Although the nick message
443 * for acptr is probably waiting in their recvq from me, its also possible
444 * that sptr will change their nick on cptr before cptr receives the
445 * nick message for acptr, which would leave acptr and sptr both alive
446 * on cptr, but only acptr alive on me, i.e. desync. This extra kill
447 * message has been absent for a while in ircu although it was a major
448 * problem when it was tried on efnet, so I don't know how big an issue it
449 * is. Probably best that this be left here, anyway...
451 ServerStats->is_kill++;
452 sendcmdto_one(&me, CMD_KILL, cptr, "%s :%s (%s)",
453 nick, cli_name(&me), type);
454 /* But if this was a nick change and not a nick introduction,
455 * we also need to ensure that we remove our local state
456 * record of the original client... Also, the rest of the
457 * net should be informed...
461 assert(!MyConnect(sptr));
462 /* Inform the rest of the net... */
463 sendcmdto_serv_butone(&me, CMD_KILL, cptr, "%s :%s (%s)",
464 nick, cli_name(&me), type);
465 /* Don't go sending off a QUIT message... */
466 SetFlag(sptr, FLAG_KILLED);
467 /* Remove them locally. */
468 exit_client_msg(cptr, sptr, &me,
470 feature_str(FEAT_HIS_SERVERNAME), type);
472 * We have killed sptr off, zero out it's pointer so if it's used
473 * again we'll know about it --Bleep
477 /* If the timestamps differ and we just killed sptr, we don't need to kill
480 if (lastnick != cli_lastnick(acptr))
483 /* Tell acptr why we are killing it. */
484 send_reply(acptr, ERR_NICKCOLLISION, nick);
486 ServerStats->is_kill++;
487 SetFlag(acptr, FLAG_KILLED);
489 * This exits the client we had before getting the NICK message
491 sendcmdto_serv_butone(&me, CMD_KILL, NULL, "%C :%s"
492 " (%s)", acptr, feature_str(FEAT_HIS_SERVERNAME),
494 exit_client_msg(cptr, acptr, &me, "Killed (%s (%s))",
495 feature_str(FEAT_HIS_SERVERNAME), type);
496 if (lastnick == cli_lastnick(acptr))
500 return set_nick_name(cptr, sptr, nick, parc, parv);