--- /dev/null
+/*
+ * 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_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_debug.h"
+#include "s_misc.h"
+#include "s_user.h"
+#include "send.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...
+*/
+static 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 (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 (!(acptr = FindClient(nick))) {
+ /*
+ * No collisions, all clear...
+ */
+ return set_nick_name(cptr, sptr, nick, parc, parv);
+ }
+ 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);
+ }
+ /*
+ * 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++;
+ IPcheck_connect_fail(acptr, 0);
+ exit_client(cptr, acptr, &me, "Overridden by other sign on");
+ return set_nick_name(cptr, sptr, nick, parc, parv);
+ }
+ /*
+ * 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);
+ 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 = FindClient(nick)) == NULL)
+ /* No collisions, all clear... */
+ return set_nick_name(cptr, sptr, nick, parc, parv);
+
+ /*
+ * 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);
+ 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++;
+ IPcheck_connect_fail(acptr, 0);
+ exit_client(cptr, acptr, &me, "Overridden by other sign on");
+ return set_nick_name(cptr, sptr, nick, parc, parv);
+ }
+ /*
+ * 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);
+}
projects / ircu2.10.12-pk.git / blobdiff