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ircu2/ircd/m_nick.c

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/*
* IRC - Internet Relay Chat, ircd/m_nick.c
* Copyright (C) 1990 Jarkko Oikarinen and
* University of Oulu, Computing Center
*
* See file AUTHORS in IRC package for additional names of
* the programmers.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 1, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id: m_nick.c 1729 2006-11-04 21:42:00Z entrope $
*/
/*
* m_functions execute protocol messages on this server:
*
* cptr is always NON-NULL, pointing to a *LOCAL* client
* structure (with an open socket connected!). This
* identifies the physical socket where the message
* originated (or which caused the m_function to be
* executed--some m_functions may call others...).
*
* sptr is the source of the message, defined by the
* prefix part of the message if present. If not
* or prefix not found, then sptr==cptr.
*
* (!IsServer(cptr)) => (cptr == sptr), because
* prefixes are taken *only* from servers...
*
* (IsServer(cptr))
* (sptr == cptr) => the message didn't
* have the prefix.
*
* (sptr != cptr && IsServer(sptr) means
* the prefix specified servername. (?)
*
* (sptr != cptr && !IsServer(sptr) means
* that message originated from a remote
* user (not local).
*
* combining
*
* (!IsServer(sptr)) means that, sptr can safely
* taken as defining the target structure of the
* message in this server.
*
* *Always* true (if 'parse' and others are working correct):
*
* 1) sptr->from == cptr (note: cptr->from == cptr)
*
* 2) MyConnect(sptr) <=> sptr == cptr (e.g. sptr
* *cannot* be a local connection, unless it's
* actually cptr!). [MyConnect(x) should probably
* be defined as (x == x->from) --msa ]
*
* parc number of variable parameter strings (if zero,
* parv is allowed to be NULL)
*
* parv a NULL terminated list of parameter pointers,
*
* parv[0], sender (prefix string), if not present
* this points to an empty string.
* parv[1]...parv[parc-1]
* pointers to additional parameters
* parv[parc] == NULL, *always*
*
* note: it is guaranteed that parv[0]..parv[parc-1] are all
* non-NULL pointers.
*/
#include "config.h"
#include "IPcheck.h"
#include "client.h"
#include "hash.h"
#include "ircd.h"
#include "ircd_chattr.h"
#include "ircd_features.h"
#include "ircd_log.h"
#include "ircd_reply.h"
#include "ircd_string.h"
#include "msg.h"
#include "numeric.h"
#include "numnicks.h"
#include "s_conf.h"
#include "s_debug.h"
#include "s_misc.h"
#include "s_user.h"
#include "send.h"
#include "shun.h"
#include "sys.h"
/* #include <assert.h> -- Now using assert in ircd_log.h */
#include <stdlib.h>
#include <string.h>
/*
* 'do_nick_name' ensures that the given parameter (nick) is really a proper
* string for a nickname (note, the 'nick' may be modified in the process...)
*
* RETURNS the length of the final NICKNAME (0, if nickname is invalid)
*
* Nickname characters are in range 'A'..'}', '_', '-', '0'..'9'
* anything outside the above set will terminate nickname.
* In addition, the first character cannot be '-' or a Digit.
*
* Note:
* The '~'-character should be allowed, but a change should be global,
* some confusion would result if only few servers allowed it...
*/
int do_nick_name(char* nick)
{
char* ch = nick;
char* end = ch + NICKLEN;
assert(0 != ch);
/* first character in [0..9-] */
if (*ch == '-' || IsDigit(*ch))
return 0;
for ( ; (ch < end) && *ch; ++ch)
if (!IsNickChar(*ch))
break;
*ch = '\0';
return (ch - nick);
}
/*
* m_nick - message handler for local clients
* parv[0] = sender prefix
* parv[1] = nickname
*/
int m_nick(struct Client* cptr, struct Client* sptr, int parc, char* parv[])
{
struct Client* acptr;
char nick[NICKLEN + 2];
char* arg;
char* s;
assert(0 != cptr);
assert(cptr == sptr);
if (IsServerPort(cptr))
return exit_client(cptr, cptr, &me, "Use a different port");
if (*(cli_name(sptr)))
if ((*parv[0] != '\0') && shun_lookup(sptr, 0))
return 0;
if (parc < 2) {
send_reply(sptr, ERR_NONICKNAMEGIVEN);
return 0;
}
/*
* Don't let them send make us send back a really long string of
* garbage
*/
arg = parv[1];
if (strlen(arg) > IRCD_MIN(NICKLEN, feature_int(FEAT_NICKLEN)))
arg[IRCD_MIN(NICKLEN, feature_int(FEAT_NICKLEN))] = '\0';
if ((s = strchr(arg, '~')))
*s = '\0';
strcpy(nick, arg);
/*
* If do_nick_name() returns a null name then reject it.
*/
if (0 == do_nick_name(nick)) {
send_reply(sptr, ERR_ERRONEUSNICKNAME, arg);
return 0;
}
/*
* Check if this is a LOCAL user trying to use a reserved (Juped)
* nick, if so tell him that it's a nick in use...
*/
if (isNickJuped(nick)) {
send_reply(sptr, ERR_NICKNAMEINUSE, nick);
return 0; /* NICK message ignored */
}
if (!EmptyString(feature_str(FEAT_CTCP_VERSIONING_NICK))) {
if (!ircd_strcmp(nick, feature_str(FEAT_CTCP_VERSIONING_NICK))) {
send_reply(sptr, ERR_NICKNAMEINUSE, nick);
return 0;
}
}
if (!(acptr = SeekClient(nick))) {
/*
* No collisions, all clear...
*/
return set_nick_name(cptr, sptr, nick, parc, parv, 0);
}
if (IsServer(acptr)) {
send_reply(sptr, ERR_NICKNAMEINUSE, nick);
return 0; /* NICK message ignored */
}
/*
* If acptr == sptr, then we have a client doing a nick
* change between *equivalent* nicknames as far as server
* is concerned (user is changing the case of his/her
* nickname or somesuch)
*/
if (acptr == sptr) {
/*
* If acptr == sptr, then we have a client doing a nick
* change between *equivalent* nicknames as far as server
* is concerned (user is changing the case of his/her
* nickname or somesuch)
*/
if (0 != strcmp(cli_name(acptr), nick)) {
/*
* Allows change of case in his/her nick
*/
return set_nick_name(cptr, sptr, nick, parc, parv, 0);
}
/*
* This is just ':old NICK old' type thing.
* Just forget the whole thing here. There is
* no point forwarding it to anywhere,
* especially since servers prior to this
* version would treat it as nick collision.
*/
return 0;
}
/*
* Note: From this point forward it can be assumed that
* acptr != sptr (point to different client structures).
*/
assert(acptr != sptr);
/*
* If the older one is "non-person", the new entry is just
* allowed to overwrite it. Just silently drop non-person,
* and proceed with the nick. This should take care of the
* "dormant nick" way of generating collisions...
*
* XXX - hmmm can this happen after one is registered?
*
* Yes, client 1 connects to IRC and registers, client 2 connects and
* sends "NICK foo" but doesn't send anything more. client 1 now does
* /nick foo, they should succeed and client 2 gets disconnected with
* the message below.
*/
if (IsUnknown(acptr) && MyConnect(acptr)) {
ServerStats->is_ref++;
if (!find_except_conf(acptr, EFLAG_IPCHECK))
IPcheck_connect_fail(acptr, 0);
exit_client(cptr, acptr, &me, "Overridden by other sign on");
return set_nick_name(cptr, sptr, nick, parc, parv, 0);
}
/*
* NICK is coming from local client connection. Just
* send error reply and ignore the command.
*/
send_reply(sptr, ERR_NICKNAMEINUSE, nick);
return 0; /* NICK message ignored */
}
/*
* ms_nick - server message handler for nicks
* parv[0] = sender prefix
* parv[1] = nickname
*
* If from server, source is client:
* parv[2] = timestamp
*
* Source is server:
* parv[2] = hopcount
* parv[3] = timestamp
* parv[4] = username
* parv[5] = hostname
* parv[6] = umode (optional)
* parv[parc-3] = IP# <- Only Protocol >= 10
* parv[parc-2] = YXX, numeric nick <- Only Protocol >= 10
* parv[parc-1] = info
* parv[0] = server
*/
int ms_nick(struct Client* cptr, struct Client* sptr, int parc, char* parv[])
{
struct Client *acptr;
char nick[NICKLEN + 2];
time_t lastnick = 0;
int differ = 1;
const char *type;
assert(0 != cptr);
assert(0 != sptr);
assert(IsServer(cptr));
if ((IsServer(sptr) && parc < 8) || parc < 3)
{
sendto_opmask_butone(0, SNO_OLDSNO, "bad NICK param count for %s from %C",
parv[1], cptr);
return need_more_params(sptr, "NICK");
}
ircd_strncpy(nick, parv[1], NICKLEN + 1);
nick[NICKLEN] = '\0';
if (IsServer(sptr))
{
lastnick = atoi(parv[3]);
if (lastnick > OLDEST_TS && !IsBurstOrBurstAck(sptr))
cli_serv(sptr)->lag = TStime() - lastnick;
}
else
{
lastnick = atoi(parv[2]);
if (lastnick > OLDEST_TS && !IsBurstOrBurstAck(sptr))
cli_serv(cli_user(sptr)->server)->lag = TStime() - lastnick;
}
/*
* If do_nick_name() returns a null name OR if the server sent a nick
* name and do_nick_name() changed it in some way (due to rules of nick
* creation) then reject it. If from a server and we reject it,
* and KILL it. -avalon 4/4/92
*/
if (!do_nick_name(nick) || strcmp(nick, parv[1]))
{
send_reply(sptr, ERR_ERRONEUSNICKNAME, parv[1]);
++ServerStats->is_kill;
sendto_opmask_butone(0, SNO_OLDSNO, "Bad Nick: %s From: %s %C", parv[1],
parv[0], cptr);
sendcmdto_one(&me, CMD_KILL, cptr, "%s :%s (%s <- %s[%s])",
IsServer(sptr) ? parv[parc - 2] : parv[0], cli_name(&me), parv[1],
nick, cli_name(cptr));
if (!IsServer(sptr))
{
/*
* bad nick _change_
*/
sendcmdto_serv_butone(&me, CMD_KILL, 0, "%s :%s (%s <- %s!%s@%s)",
parv[0], cli_name(&me), cli_name(cptr), parv[0],
cli_user(sptr) ? cli_username(sptr) : "",
cli_user(sptr) ? cli_name(cli_user(sptr)->server) :
cli_name(cptr));
}
return 0;
}
/* Check against nick name collisions. */
if ((acptr = SeekClient(nick)) == NULL)
/* No collisions, all clear... */
return set_nick_name(cptr, sptr, nick, parc, parv, 0);
/*
* If acptr == sptr, then we have a client doing a nick
* change between *equivalent* nicknames as far as server
* is concerned (user is changing the case of his/her
* nickname or somesuch)
*/
if (acptr == sptr)
{
if (strcmp(cli_name(acptr), nick) != 0)
/* Allows change of case in his/her nick */
return set_nick_name(cptr, sptr, nick, parc, parv, 0);
else
/* Setting their nick to what it already is? Ignore it. */
return 0;
}
/* now we know we have a real collision. */
/*
* Note: From this point forward it can be assumed that
* acptr != sptr (point to different client structures).
*/
assert(acptr != sptr);
/*
* If the older one is "non-person", the new entry is just
* allowed to overwrite it. Just silently drop non-person,
* and proceed with the nick. This should take care of the
* "dormant nick" way of generating collisions...
*/
if (IsUnknown(acptr) && MyConnect(acptr))
{
ServerStats->is_ref++;
if (!find_except_conf(acptr, EFLAG_IPCHECK))
IPcheck_connect_fail(acptr, 0);
exit_client(cptr, acptr, &me, "Overridden by other sign on");
return set_nick_name(cptr, sptr, nick, parc, parv, 0);
}
/*
* Decide, we really have a nick collision and deal with it
*/
/*
* NICK was coming from a server connection.
* This means we have a race condition (two users signing on
* at the same time), or two net fragments reconnecting with the same nick.
* The latter can happen because two different users connected
* or because one and the same user switched server during a net break.
* If the TimeStamps are equal, we kill both (or only 'new'
* if it was a ":server NICK new ...").
* Otherwise we kill the youngest when user@host differ,
* or the oldest when they are the same.
* We treat user and ~user as different, because if it wasn't
* a faked ~user the AUTH wouldn't have added the '~'.
* --Run
*
*/
if (IsServer(sptr))
{
struct irc_in_addr ip;
/*
* A new NICK being introduced by a neighbouring
* server (e.g. message type ":server NICK new ..." received)
*
* compare IP address and username
*/
base64toip(parv[parc - 3], &ip);
differ = (0 != memcmp(&cli_ip(acptr), &ip, sizeof(cli_ip(acptr)))) ||
(0 != ircd_strcmp(cli_user(acptr)->username, parv[4]));
sendto_opmask_butone(0, SNO_OLDSNO, "Nick collision on %C (%C %Tu <- "
"%C %Tu (%s user@host))", acptr, cli_from(acptr),
cli_lastnick(acptr), cptr, lastnick,
differ ? "Different" : "Same");
}
else
{
/*
* A NICK change has collided (e.g. message type ":old NICK new").
*
* compare IP address and username
*/
differ = (0 != memcmp(&cli_ip(acptr), &cli_ip(sptr), sizeof(cli_ip(acptr)))) ||
(0 != ircd_strcmp(cli_user(acptr)->username, cli_user(sptr)->username));
sendto_opmask_butone(0, SNO_OLDSNO, "Nick change collision from %C to "
"%C (%C %Tu <- %C %Tu)", sptr, acptr, cli_from(acptr),
cli_lastnick(acptr), cptr, lastnick);
}
type = differ ? "overruled by older nick" : "nick collision from same user@host";
/*
* Now remove (kill) the nick on our side if it is the youngest.
* If no timestamp was received, we ignore the incoming nick
* (and expect a KILL for our legit nick soon ):
* When the timestamps are equal we kill both nicks. --Run
* acptr->from != cptr should *always* be true (?).
*
* This exits the client sending the NICK message
*/
if ((differ && lastnick >= cli_lastnick(acptr)) ||
(!differ && lastnick <= cli_lastnick(acptr)))
{
ServerStats->is_kill++;
if (!IsServer(sptr))
{
/* If this was a nick change and not a nick introduction, we
* need to ensure that we remove our record of the client, and
* send a KILL to the whole network.
*/
assert(!MyConnect(sptr));
/* Inform the rest of the net... */
sendcmdto_serv_butone(&me, CMD_KILL, 0, "%C :%s (%s)",
sptr, cli_name(&me), type);
/* Don't go sending off a QUIT message... */
SetFlag(sptr, FLAG_KILLED);
/* Remove them locally. */
exit_client_msg(cptr, sptr, &me,
"Killed (%s (%s))",
feature_str(FEAT_HIS_SERVERNAME), type);
}
else
{
/* If the origin is a server, this was a new client, so we only
* send the KILL in the direction it came from. We have no
* client record that we would have to clean up.
*/
sendcmdto_one(&me, CMD_KILL, cptr, "%s :%s (%s)",
parv[parc - 2], cli_name(&me), type);
}
/* If the timestamps differ and we just killed sptr, we don't need to kill
* acptr as well.
*/
if (lastnick != cli_lastnick(acptr))
return 0;
}
/* Tell acptr why we are killing it. */
send_reply(acptr, ERR_NICKCOLLISION, nick);
ServerStats->is_kill++;
SetFlag(acptr, FLAG_KILLED);
/*
* This exits the client we had before getting the NICK message
*/
sendcmdto_serv_butone(&me, CMD_KILL, NULL, "%C :%s (%s)",
acptr, feature_str(FEAT_HIS_SERVERNAME),
type);
exit_client_msg(cptr, acptr, &me, "Killed (%s (%s))",
feature_str(FEAT_HIS_SERVERNAME), type);
if (lastnick == cli_lastnick(acptr))
return 0;
if (sptr == NULL)
return 0;
return set_nick_name(cptr, sptr, nick, parc, parv, 0);
}
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