Exemplo n.º 1
0
/*
 * Create a new struct Client structure and set it to initial state.
 *
 *   from == NULL,   create local client (a client connected to a socket).
 *
 *   from != NULL,   create remote client (behind a socket associated with
 *                   the client defined by 'from').
 *                   ('from' is a local client!!).
 */
struct Client* make_client(struct Client *from, int status)
{
  struct Client* cptr = 0;
  struct Connection* con = 0;

  assert(!from || cli_verify(from));

  cptr = alloc_client();

  assert(0 != cptr);
  assert(!cli_magic(cptr));
  assert(0 == from || 0 != cli_connect(from));

  if (!from) { /* local client, allocate a struct Connection */
    con = alloc_connection();

    assert(0 != con);
    assert(!con_magic(con));

    con_magic(con) = CONNECTION_MAGIC;
    con_fd(con) = -1; /* initialize struct Connection */
    con_freeflag(con) = 0;
    con_nextnick(con) = CurrentTime - NICK_DELAY;
    con_nexttarget(con) = CurrentTime - (TARGET_DELAY * (STARTTARGETS - 1));
    con_handler(con) = UNREGISTERED_HANDLER;
    con_client(con) = cptr;

    cli_local(cptr) = 1; /* Set certain fields of the struct Client */
    cli_since(cptr) = cli_lasttime(cptr) = cli_firsttime(cptr) = CurrentTime;
    cli_lastnick(cptr) = TStime();
  } else
    con = cli_connect(from); /* use 'from's connection */

  assert(0 != con);
  assert(con_verify(con));

  cli_magic(cptr) = CLIENT_MAGIC;
  cli_connect(cptr) = con; /* set the connection and other fields */
  cli_status(cptr) = status;
  cli_hnext(cptr) = cptr;
  strcpy(cli_username(cptr), "unknown");

  return cptr;
}
Exemplo n.º 2
0
/*
 * 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);
    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);
}
Exemplo n.º 3
0
/*
 * 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;
  int            samelastnick = 0;
  
  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 (0 == do_nick_name(nick) || 0 != 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.
   *
   * Put this 'if' here so that the nesting goes nicely on the screen :)
   * We check against server name list before determining if the nickname
   * is present in the nicklist (due to the way the below for loop is
   * constructed). -avalon
   */
   
  assert(NULL == strchr(nick,'.'));

  acptr = FindClient(nick);
  if (!acptr) {
    /*
     * No collisions, all clear...
     */
    return set_nick_name(cptr, sptr, nick, parc, parv);
  }
  assert(0 != acptr);

  /*
   * 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)
      /*
       * 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;                        /* NICK Message ignored */
    else
      /*
       * Allows change of case in his/her nick
       */
      return set_nick_name(cptr, sptr, nick, parc, parv);
  }

  /*
   * 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(cli_ip(acptr));
    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)) {
    /*
     * A new NICK being introduced by a neighbouring
     * server (e.g. message type ":server NICK new ..." received)
     *
     * compare IP address and username
     */
    differ =  (cli_ip(acptr).s_addr != htonl(base64toint(parv[parc - 3]))) ||
              (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 =  (cli_ip(acptr).s_addr != cli_ip(sptr).s_addr) ||
              (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);
  }
  /*
   * 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 (cli_from(acptr) != cptr) {
    if ((differ && lastnick >= cli_lastnick(acptr)) ||
	(!differ && lastnick <= cli_lastnick(acptr))) {
      if (!IsServer(sptr)) {
        ++ServerStats->is_kill;
	sendcmdto_serv_butone(&me, CMD_KILL, NULL, "%C :%s (Nick collision)",
			      sptr, cli_name(&me));
        assert(!MyConnect(sptr));

        SetFlag(sptr, FLAG_KILLED);

	exit_client_msg(cptr, sptr, &me,
			       "Killed (%s (Nick collision))",
			       feature_str(FEAT_HIS_SERVERNAME));

	sptr = 0; /* Make sure we don't use the dead client */

      } else {
        /* We need to kill this incoming client, which hasn't been properly registered yet.
         * Send a KILL message upstream to the server it came from  */
        sendcmdto_one(&me, CMD_KILL, sptr, "%s :%s (Nick collision)", parv[parc-2], cli_name(&me));
      } 
      /* If the two have the same TS then we want to kill both sides, so
       * don't leave yet!
       */
      if (lastnick != cli_lastnick(acptr))
        return 0;                /* Ignore the NICK */
    }
    send_reply(acptr, ERR_NICKCOLLISION, nick);
  }

  ++ServerStats->is_kill;
  SetFlag(acptr, FLAG_KILLED);
  
  if (lastnick == cli_lastnick(acptr))
    samelastnick = 1;
    
  /*
   * This exits the client we had before getting the NICK message
   */
  if (differ) {
    sendcmdto_serv_butone(&me, CMD_KILL, NULL, "%C :%s (older nick "
			  "overruled)", acptr, cli_name(&me));
    if (MyConnect(acptr)) {
      sendcmdto_one(acptr, CMD_QUIT, cptr, ":Killed (%s (older "
		    "nick overruled))",  feature_str(FEAT_HIS_SERVERNAME));
      sendcmdto_one(&me, CMD_KILL, acptr, "%C :%s (older nick "
		    "overruled)", acptr, feature_str(FEAT_HIS_SERVERNAME));
    }

    exit_client_msg(cptr, acptr, &me, "Killed (%s (older nick "
		    "overruled))", feature_str(FEAT_HIS_SERVERNAME));
  }
  else {
    sendcmdto_serv_butone(&me, CMD_KILL, NULL, "%C :%s (nick collision from "
			  "same user@host)", acptr, cli_name(&me));
    if (MyConnect(acptr)) {
      sendcmdto_one(acptr, CMD_QUIT, cptr, ":Killed (%s (nick "
		    "collision from same user@host))",
		    feature_str(FEAT_HIS_SERVERNAME));
      sendcmdto_one(&me, CMD_KILL, acptr, "%C :%s (older nick "
		    "overruled)", acptr, feature_str(FEAT_HIS_SERVERNAME));
    }
    exit_client_msg(cptr, acptr, &me, "Killed (%s (nick collision from "
		    "same user@host))", feature_str(FEAT_HIS_SERVERNAME));
  }
  if (samelastnick)
    return 0;

  assert(0 != sptr);
  return set_nick_name(cptr, sptr, nick, parc, parv);
}
Exemplo n.º 4
0
/** Handle a connection that has sent a valid PASS and SERVER.
 * @param cptr New peer server.
 * @param aconf Connect block for \a cptr.
 * @return Zero.
 */
int server_estab(struct Client *cptr, struct ConfItem *aconf)
{
  struct Client* acptr = 0;
  const char*    inpath;
  int            i;

  assert(0 != cptr);
  assert(0 != cli_local(cptr));

  inpath = cli_name(cptr);

  if (IsUnknown(cptr)) {
    if (aconf->passwd[0])
      sendrawto_one(cptr, MSG_PASS " :%s", aconf->passwd);
    /*
     *  Pass my info to the new server
     */
    sendrawto_one(cptr, MSG_SERVER " %s 1 %Tu %Tu J%s %s%s +%s6 :%s",
		  cli_name(&me), cli_serv(&me)->timestamp,
		  cli_serv(cptr)->timestamp, MAJOR_PROTOCOL, NumServCap(&me),
		  feature_bool(FEAT_HUB) ? "h" : "",
		  *(cli_info(&me)) ? cli_info(&me) : "IRCers United");
  }

  det_confs_butmask(cptr, CONF_SERVER);

  if (!IsHandshake(cptr))
    hAddClient(cptr);
  SetServer(cptr);
  cli_handler(cptr) = SERVER_HANDLER;
  Count_unknownbecomesserver(UserStats);
  SetBurst(cptr);

/*    nextping = CurrentTime; */

  /*
   * NOTE: check for acptr->user == cptr->serv->user is necessary to insure
   * that we got the same one... bleah
   */
  if (cli_serv(cptr)->user && *(cli_serv(cptr))->by &&
      (acptr = findNUser(cli_serv(cptr)->by))) {
    if (cli_user(acptr) == cli_serv(cptr)->user) {
      sendcmdto_one(&me, CMD_NOTICE, acptr, "%C :Link with %s established.",
                    acptr, inpath);
    }
    else {
      /*
       * if not the same client, set by to empty string
       */
      acptr = 0;
      *(cli_serv(cptr))->by = '\0';
    }
  }

  sendto_opmask(acptr, SNO_OLDSNO, "Link with %s established.", inpath);
  cli_serv(cptr)->up = &me;
  cli_serv(cptr)->updown = add_dlink(&(cli_serv(&me))->down, cptr);
  sendto_opmask(0, SNO_NETWORK, "Net junction: %s %s", cli_name(&me),
                cli_name(cptr));
  SetJunction(cptr);
  /*
   * Old sendto_serv_but_one() call removed because we now
   * need to send different names to different servers
   * (domain name matching) Send new server to other servers.
   */
  for (i = 0; i <= HighestFd; i++)
  {
    if (!(acptr = LocalClientArray[i]) || !IsServer(acptr) ||
        acptr == cptr || IsMe(acptr))
      continue;
    if (!match(cli_name(&me), cli_name(cptr)))
      continue;
    sendcmdto_one(&me, CMD_SERVER, acptr,
		  "%s 2 0 %Tu J%02u %s%s +%s%s%s :%s", cli_name(cptr),
		  cli_serv(cptr)->timestamp, Protocol(cptr), NumServCap(cptr),
		  IsHub(cptr) ? "h" : "", IsService(cptr) ? "s" : "",
		  IsIPv6(cptr) ? "6" : "", cli_info(cptr));
  }

  /* Send these as early as possible so that glined users/juped servers can
   * be removed from the network while the remote server is still chewing
   * our burst.
   */
  gline_burst(cptr);
  jupe_burst(cptr);

  /*
   * Pass on my client information to the new server
   *
   * First, pass only servers (idea is that if the link gets
   * canceled because the server was already there,
   * there are no NICK's to be canceled...). Of course,
   * if cancellation occurs, all this info is sent anyway,
   * and I guess the link dies when a read is attempted...? --msa
   *
   * Note: Link cancellation to occur at this point means
   * that at least two servers from my fragment are building
   * up connection this other fragment at the same time, it's
   * a race condition, not the normal way of operation...
   */

  for (acptr = &me; acptr; acptr = cli_prev(acptr)) {
    /* acptr->from == acptr for acptr == cptr */
    if (cli_from(acptr) == cptr)
      continue;
    if (IsServer(acptr)) {
      const char* protocol_str;

      if (Protocol(acptr) > 9)
        protocol_str = IsBurst(acptr) ? "J" : "P";
      else
        protocol_str = IsBurst(acptr) ? "J0" : "P0";

      if (0 == match(cli_name(&me), cli_name(acptr)))
        continue;
      sendcmdto_one(cli_serv(acptr)->up, CMD_SERVER, cptr,
		    "%s %d 0 %Tu %s%u %s%s +%s%s%s :%s", cli_name(acptr),
		    cli_hopcount(acptr) + 1, cli_serv(acptr)->timestamp,
		    protocol_str, Protocol(acptr), NumServCap(acptr),
		    IsHub(acptr) ? "h" : "", IsService(acptr) ? "s" : "",
		    IsIPv6(acptr) ? "6" : "", cli_info(acptr));
    }
  }

  for (acptr = &me; acptr; acptr = cli_prev(acptr))
  {
    /* acptr->from == acptr for acptr == cptr */
    if (cli_from(acptr) == cptr)
      continue;
    if (IsUser(acptr))
    {
      char xxx_buf[25];
      char *s = umode_str(acptr);
      sendcmdto_one(cli_user(acptr)->server, CMD_NICK, cptr,
		    "%s %d %Tu %s %s %s%s%s%s %s%s :%s",
		    cli_name(acptr), cli_hopcount(acptr) + 1, cli_lastnick(acptr),
		    cli_user(acptr)->username, cli_user(acptr)->realhost,
		    *s ? "+" : "", s, *s ? " " : "",
		    iptobase64(xxx_buf, &cli_ip(acptr), sizeof(xxx_buf), IsIPv6(cptr)),
		    NumNick(acptr), cli_info(acptr));
    }
  }
  /*
   * Last, send the BURST.
   * (Or for 2.9 servers: pass all channels plus statuses)
   */
  {
    struct Channel *chptr;
    for (chptr = GlobalChannelList; chptr; chptr = chptr->next)
      send_channel_modes(cptr, chptr);
  }
  sendcmdto_one(&me, CMD_END_OF_BURST, cptr, "");
  return 0;
}