src/modules/m_spanningtree/utils.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2007 InspIRCd Development Team
   6  * See: http://www.inspircd.org/wiki/index.php/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *            the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 #include "configreader.h"
  15 #include "users.h"
  16 #include "channels.h"
  17 #include "modules.h"
  18 #include "commands/cmd_whois.h"
  19 #include "commands/cmd_stats.h"
  20 #include "socket.h"
  21 #include "inspircd.h"
  22 #include "wildcard.h"
  23 #include "xline.h"
  24 #include "transport.h"
  25 #include "socketengine.h"
  26
  27 #include "m_spanningtree/main.h"
  28 #include "m_spanningtree/utils.h"
  29 #include "m_spanningtree/treeserver.h"
  30 #include "m_spanningtree/link.h"
  31 #include "m_spanningtree/treesocket.h"
  32 #include "m_spanningtree/resolvers.h"
  33
  34 /* $ModDep: m_spanningtree/timesynctimer.h m_spanningtree/resolvers.h m_spanningtree/main.h m_spanningtree/utils.h m_spanningtree/treeserver.h m_spanningtree/link.h m_spanningtree/treesocket.h */
  35
  36 /** Yay for fast searches!
  37  * This is hundreds of times faster than recursion
  38  * or even scanning a linked list, especially when
  39  * there are more than a few servers to deal with.
  40  * (read as: lots).
  41  */
  42 TreeServer* SpanningTreeUtilities::FindServer(const std::string &ServerName)
  43 {
  44         server_hash::iterator iter;
  45         iter = serverlist.find(ServerName.c_str());
  46         if (iter != serverlist.end())
  47         {
  48                 return iter->second;
  49         }
  50         else
  51         {
  52                 return NULL;
  53         }
  54 }
  55
  56 TreeSocket* SpanningTreeUtilities::FindBurstingServer(const std::string &ServerName)
  57 {
  58         std::map<irc::string,TreeSocket*>::iterator iter;
  59         iter = burstingserverlist.find(ServerName.c_str());
  60         if (iter != burstingserverlist.end())
  61         {
  62                 return iter->second;
  63         }
  64         else
  65         {
  66                 return NULL;
  67         }
  68 }
  69
  70 void SpanningTreeUtilities::AddBurstingServer(const std::string &ServerName, TreeSocket* s)
  71 {
  72         std::map<irc::string,TreeSocket*>::iterator iter;
  73         iter = burstingserverlist.find(ServerName.c_str());
  74         if (iter == burstingserverlist.end())
  75                 burstingserverlist[ServerName.c_str()] = s;
  76 }
  77
  78 void SpanningTreeUtilities::DelBurstingServer(TreeSocket* s)
  79 {
  80          for (std::map<irc::string,TreeSocket*>::iterator iter = burstingserverlist.begin(); iter != burstingserverlist.end(); iter++)
  81          {
  82                  if (iter->second == s)
  83                  {
  84                          burstingserverlist.erase(iter);
  85                          return;
  86                  }
  87          }
  88 }
  89
  90 /** Returns the locally connected server we must route a
  91  * message through to reach server 'ServerName'. This
  92  * only applies to one-to-one and not one-to-many routing.
  93  * See the comments for the constructor of TreeServer
  94  * for more details.
  95  */
  96 TreeServer* SpanningTreeUtilities::BestRouteTo(const std::string &ServerName)
  97 {
  98         if (ServerName.c_str() == TreeRoot->GetName())
  99                 return NULL;
 100         TreeServer* Found = FindServer(ServerName);
 101         if (Found)
 102         {
 103                 return Found->GetRoute();
 104         }
 105         else
 106         {
 107                 return NULL;
 108         }
 109 }
 110
 111 /** Find the first server matching a given glob mask.
 112  * Theres no find-using-glob method of hash_map [awwww :-(]
 113  * so instead, we iterate over the list using an iterator
 114  * and match each one until we get a hit. Yes its slow,
 115  * deal with it.
 116  */
 117 TreeServer* SpanningTreeUtilities::FindServerMask(const std::string &ServerName)
 118 {
 119         for (server_hash::iterator i = serverlist.begin(); i != serverlist.end(); i++)
 120         {
 121                 if (match(i->first.c_str(),ServerName.c_str()))
 122                         return i->second;
 123         }
 124         return NULL;
 125 }
 126
 127 /* A convenient wrapper that returns true if a server exists */
 128 bool SpanningTreeUtilities::IsServer(const std::string &ServerName)
 129 {
 130         return (FindServer(ServerName) != NULL);
 131 }
 132
 133 SpanningTreeUtilities::SpanningTreeUtilities(InspIRCd* Instance, ModuleSpanningTree* C) : ServerInstance(Instance), Creator(C)
 134 {
 135         Bindings.clear();
 136
 137         lines_to_apply = 0;
 138
 139         this->TreeRoot = new TreeServer(this, ServerInstance, ServerInstance->Config->ServerName, ServerInstance->Config->ServerDesc);
 140
 141         modulelist* ml = ServerInstance->FindInterface("InspSocketHook");
 142
 143         /* Did we find any modules? */
 144         if (ml)
 145         {
 146                 /* Yes, enumerate them all to find out the hook name */
 147                 for (modulelist::iterator m = ml->begin(); m != ml->end(); m++)
 148                 {
 149                         /* Make a request to it for its name, its implementing
 150                          * InspSocketHook so we know its safe to do this
 151                          */
 152                         std::string name = InspSocketNameRequest((Module*)Creator, *m).Send();
 153                         /* Build a map of them */
 154                         hooks[name.c_str()] = *m;
 155                         hooknames.push_back(name);
 156                 }
 157         }
 158
 159         this->ReadConfiguration(true);
 160 }
 161
 162 SpanningTreeUtilities::~SpanningTreeUtilities()
 163 {
 164         for (unsigned int i = 0; i < Bindings.size(); i++)
 165         {
 166                 ServerInstance->SE->DelFd(Bindings[i]);
 167                 Bindings[i]->Close();
 168                 DELETE(Bindings[i]);
 169         }
 170         while (TreeRoot->ChildCount())
 171         {
 172                 TreeServer* child_server = TreeRoot->GetChild(0);
 173                 if (child_server)
 174                 {
 175                         TreeSocket* sock = child_server->GetSocket();
 176                         ServerInstance->SE->DelFd(sock);
 177                         sock->Close();
 178                         DELETE(sock);
 179                 }
 180         }
 181         delete TreeRoot;
 182 }
 183
 184 void SpanningTreeUtilities::AddThisServer(TreeServer* server, TreeServerList &list)
 185 {
 186         if (list.find(server) == list.end())
 187                 list[server] = server;
 188 }
 189
 190 /* returns a list of DIRECT servernames for a specific channel */
 191 void SpanningTreeUtilities::GetListOfServersForChannel(chanrec* c, TreeServerList &list, char status, const CUList &exempt_list)
 192 {
 193         CUList *ulist;
 194         switch (status)
 195         {
 196                 case '@':
 197                         ulist = c->GetOppedUsers();
 198                 break;
 199                 case '%':
 200                         ulist = c->GetHalfoppedUsers();
 201                 break;
 202                 case '+':
 203                         ulist = c->GetVoicedUsers();
 204                 break;
 205                 default:
 206                         ulist = c->GetUsers();
 207                 break;
 208         }
 209         for (CUList::iterator i = ulist->begin(); i != ulist->end(); i++)
 210         {
 211                 if ((i->second->GetFd() < 0) && (exempt_list.find(i->second) == exempt_list.end()))
 212                 {
 213                         TreeServer* best = this->BestRouteTo(i->second->server);
 214                         if (best)
 215                                 AddThisServer(best,list);
 216                 }
 217         }
 218         return;
 219 }
 220
 221 bool SpanningTreeUtilities::DoOneToAllButSenderRaw(const std::string &data, const std::string &omit, const std::string &prefix, const irc::string &command, std::deque<std::string> &params)
 222 {
 223         char pfx = 0;
 224         TreeServer* omitroute = this->BestRouteTo(omit);
 225         if ((command == "NOTICE") || (command == "PRIVMSG"))
 226         {
 227                 if (params.size() >= 2)
 228                 {
 229                         /* Prefixes */
 230                         if ((*(params[0].c_str()) == '@') || (*(params[0].c_str()) == '%') || (*(params[0].c_str()) == '+'))
 231                         {
 232                                 pfx = params[0][0];
 233                                 params[0] = params[0].substr(1, params[0].length()-1);
 234                         }
 235                         if ((*(params[0].c_str()) != '#') && (*(params[0].c_str()) != '$'))
 236                         {
 237                                 // special routing for private messages/notices
 238                                 userrec* d = ServerInstance->FindNick(params[0]);
 239                                 if (d)
 240                                 {
 241                                         std::deque<std::string> par;
 242                                         par.push_back(params[0]);
 243                                         par.push_back(":"+params[1]);
 244                                         this->DoOneToOne(prefix,command.c_str(),par,d->server);
 245                                         return true;
 246                                 }
 247                         }
 248                         else if (*(params[0].c_str()) == '$')
 249                         {
 250                                 std::deque<std::string> par;
 251                                 par.push_back(params[0]);
 252                                 par.push_back(":"+params[1]);
 253                                 this->DoOneToAllButSender(prefix,command.c_str(),par,omitroute->GetName());
 254                                 return true;
 255                         }
 256                         else
 257                         {
 258                                 chanrec* c = ServerInstance->FindChan(params[0]);
 259                                 userrec* u = ServerInstance->FindNick(prefix);
 260                                 if (c && u)
 261                                 {
 262                                         CUList elist;
 263                                         TreeServerList list;
 264                                         FOREACH_MOD(I_OnBuildExemptList, OnBuildExemptList((command == "PRIVMSG" ? MSG_PRIVMSG : MSG_NOTICE), c, u, pfx, elist));
 265                                         GetListOfServersForChannel(c,list,pfx,elist);
 266
 267                                         for (TreeServerList::iterator i = list.begin(); i != list.end(); i++)
 268                                         {
 269                                                 TreeSocket* Sock = i->second->GetSocket();
 270                                                 if ((Sock) && (i->second->GetName() != omit) && (omitroute != i->second))
 271                                                 {
 272                                                         Sock->WriteLine(data);
 273                                                 }
 274                                         }
 275                                         return true;
 276                                 }
 277                         }
 278                 }
 279         }
 280         unsigned int items =this->TreeRoot->ChildCount();
 281         for (unsigned int x = 0; x < items; x++)
 282         {
 283                 TreeServer* Route = this->TreeRoot->GetChild(x);
 284                 if ((Route) && (Route->GetSocket()) && (Route->GetName() != omit) && (omitroute != Route))
 285                 {
 286                         TreeSocket* Sock = Route->GetSocket();
 287                         if (Sock)
 288                                 Sock->WriteLine(data);
 289                 }
 290         }
 291         return true;
 292 }
 293
 294 bool SpanningTreeUtilities::DoOneToAllButSender(const std::string &prefix, const std::string &command, std::deque<std::string> &params, std::string omit)
 295 {
 296         TreeServer* omitroute = this->BestRouteTo(omit);
 297         std::string FullLine = ":" + prefix + " " + command;
 298         unsigned int words = params.size();
 299         for (unsigned int x = 0; x < words; x++)
 300         {
 301                 FullLine = FullLine + " " + params[x];
 302         }
 303         unsigned int items = this->TreeRoot->ChildCount();
 304         for (unsigned int x = 0; x < items; x++)
 305         {
 306                 TreeServer* Route = this->TreeRoot->GetChild(x);
 307                 // Send the line IF:
 308                 // The route has a socket (its a direct connection)
 309                 // The route isnt the one to be omitted
 310                 // The route isnt the path to the one to be omitted
 311                 if ((Route) && (Route->GetSocket()) && (Route->GetName() != omit) && (omitroute != Route))
 312                 {
 313                         TreeSocket* Sock = Route->GetSocket();
 314                         if (Sock)
 315                                 Sock->WriteLine(FullLine);
 316                 }
 317         }
 318         return true;
 319 }
 320
 321 bool SpanningTreeUtilities::DoOneToMany(const std::string &prefix, const std::string &command, std::deque<std::string> &params)
 322 {
 323         std::string FullLine = ":" + prefix + " " + command;
 324         unsigned int words = params.size();
 325         for (unsigned int x = 0; x < words; x++)
 326         {
 327                 FullLine = FullLine + " " + params[x];
 328         }
 329         unsigned int items = this->TreeRoot->ChildCount();
 330         for (unsigned int x = 0; x < items; x++)
 331         {
 332                 TreeServer* Route = this->TreeRoot->GetChild(x);
 333                 if (Route && Route->GetSocket())
 334                 {
 335                         TreeSocket* Sock = Route->GetSocket();
 336                         if (Sock)
 337                                 Sock->WriteLine(FullLine);
 338                 }
 339         }
 340         return true;
 341 }
 342
 343 bool SpanningTreeUtilities::DoOneToMany(const char* prefix, const char* command, std::deque<std::string> &params)
 344 {
 345         std::string spfx = prefix;
 346         std::string scmd = command;
 347         return this->DoOneToMany(spfx, scmd, params);
 348 }
 349
 350 bool SpanningTreeUtilities::DoOneToAllButSender(const char* prefix, const char* command, std::deque<std::string> &params, std::string omit)
 351 {
 352         std::string spfx = prefix;
 353         std::string scmd = command;
 354         return this->DoOneToAllButSender(spfx, scmd, params, omit);
 355 }
 356
 357 bool SpanningTreeUtilities::DoOneToOne(const std::string &prefix, const std::string &command, std::deque<std::string> &params, std::string target)
 358 {
 359         TreeServer* Route = this->BestRouteTo(target);
 360         if (Route)
 361         {
 362                 std::string FullLine = ":" + prefix + " " + command;
 363                 unsigned int words = params.size();
 364                 for (unsigned int x = 0; x < words; x++)
 365                 {
 366                         FullLine = FullLine + " " + params[x];
 367                 }
 368                 if (Route && Route->GetSocket())
 369                 {
 370                         TreeSocket* Sock = Route->GetSocket();
 371                         if (Sock)
 372                                 Sock->WriteLine(FullLine);
 373                 }
 374                 return true;
 375         }
 376         else
 377         {
 378                 return false;
 379         }
 380 }
 381
 382 void SpanningTreeUtilities::RefreshIPCache()
 383 {
 384         ValidIPs.clear();
 385         for (std::vector<Link>::iterator L = LinkBlocks.begin(); L != LinkBlocks.end(); L++)
 386         {
 387                 if ((L->IPAddr != "") && (L->RecvPass != "") && (L->SendPass != "") && (L->Name != "") && (L->Port))
 388                 {
 389                         ValidIPs.push_back(L->IPAddr);
 390
 391                         if (L->AllowMask.length())
 392                                 ValidIPs.push_back(L->AllowMask);
 393
 394                         /* Needs resolving */
 395                         bool ipvalid = true;
 396                         QueryType start_type = DNS_QUERY_A;
 397 #ifdef IPV6
 398                         start_type = DNS_QUERY_AAAA;
 399                         if (strchr(L->IPAddr.c_str(),':'))
 400                         {
 401                                 in6_addr n;
 402                                 if (inet_pton(AF_INET6, L->IPAddr.c_str(), &n) < 1)
 403                                         ipvalid = false;
 404                         }
 405                         else
 406                         {
 407                                 in_addr n;
 408                                 if (inet_aton(L->IPAddr.c_str(),&n) < 1)
 409                                         ipvalid = false;
 410                         }
 411 #else
 412                         in_addr n;
 413                         if (inet_aton(L->IPAddr.c_str(),&n) < 1)
 414                                 ipvalid = false;
 415 #endif
 416                         if (!ipvalid)
 417                         {
 418                                 try
 419                                 {
 420                                         bool cached;
 421                                         SecurityIPResolver* sr = new SecurityIPResolver((Module*)this->Creator, this, ServerInstance, L->IPAddr, *L, cached, start_type);
 422                                         ServerInstance->AddResolver(sr, cached);
 423                                 }
 424                                 catch (ModuleException& e)
 425                                 {
 426                                 }
 427                         }
 428                 }
 429         }
 430 }
 431
 432 void SpanningTreeUtilities::ReadConfiguration(bool rebind)
 433 {
 434         ConfigReader* Conf = new ConfigReader(ServerInstance);
 435         if (rebind)
 436         {
 437                 for (int j =0; j < Conf->Enumerate("bind"); j++)
 438                 {
 439                         std::string Type = Conf->ReadValue("bind","type",j);
 440                         std::string IP = Conf->ReadValue("bind","address",j);
 441                         std::string Port = Conf->ReadValue("bind","port",j);
 442                         std::string transport = Conf->ReadValue("bind","transport",j);
 443                         if (Type == "servers")
 444                         {
 445                                 irc::portparser portrange(Port, false);
 446                                 int portno = -1;
 447                                 while ((portno = portrange.GetToken()))
 448                                 {
 449                                         if (IP == "*")
 450                                                 IP = "";
 451
 452                                         if ((!transport.empty()) && (hooks.find(transport.c_str()) ==  hooks.end()))
 453                                         {
 454                                                 ServerInstance->Log(DEFAULT,"m_spanningtree: WARNING: Can't find transport type '%s' for port %s:%s - maybe you forgot to load it BEFORE m_spanningtree in your config file? - Skipping this port binding", transport.c_str(), IP.c_str(), Port.c_str());
 455                                                 break;
 456                                         }
 457
 458                                         TreeSocket* listener = new TreeSocket(this, ServerInstance, IP.c_str(), portno, true, 10, transport.empty() ? NULL : hooks[transport.c_str()]);
 459                                         if (listener->GetState() == I_LISTENING)
 460                                         {
 461                                                 ServerInstance->Log(DEFAULT,"m_spanningtree: Binding server port %s:%d successful!", IP.c_str(), portno);
 462                                                 Bindings.push_back(listener);
 463                                         }
 464                                         else
 465                                         {
 466                                                 ServerInstance->Log(DEFAULT,"m_spanningtree: Warning: Failed to bind server port: %s:%d: %s",IP.c_str(), portno, strerror(errno));
 467                                                 listener->Close();
 468                                                 DELETE(listener);
 469                                         }
 470                                 }
 471                         }
 472                 }
 473         }
 474         FlatLinks = Conf->ReadFlag("options","flatlinks",0);
 475         HideULines = Conf->ReadFlag("options","hideulines",0);
 476         AnnounceTSChange = Conf->ReadFlag("options","announcets",0);
 477         EnableTimeSync = Conf->ReadFlag("timesync","enable",0);
 478         MasterTime = Conf->ReadFlag("timesync", "master", 0);
 479         ChallengeResponse = !Conf->ReadFlag("options", "disablehmac", 0);
 480         quiet_bursts = Conf->ReadFlag("options", "quietbursts", 0);
 481         LinkBlocks.clear();
 482         ValidIPs.clear();
 483         for (int j =0; j < Conf->Enumerate("link"); j++)
 484         {
 485                 Link L;
 486                 std::string Allow = Conf->ReadValue("link", "allowmask", j);
 487                 L.Name = (Conf->ReadValue("link", "name", j)).c_str();
 488                 L.AllowMask = Allow;
 489                 L.IPAddr = Conf->ReadValue("link", "ipaddr", j);
 490                 L.FailOver = Conf->ReadValue("link", "failover", j).c_str();
 491                 L.Port = Conf->ReadInteger("link", "port", j, true);
 492                 L.SendPass = Conf->ReadValue("link", "sendpass", j);
 493                 L.RecvPass = Conf->ReadValue("link", "recvpass", j);
 494                 L.AutoConnect = Conf->ReadInteger("link", "autoconnect", j, true);
 495                 L.HiddenFromStats = Conf->ReadFlag("link", "hidden", j);
 496                 L.Timeout = Conf->ReadInteger("link", "timeout", j, true);
 497                 L.Hook = Conf->ReadValue("link", "transport", j);
 498                 L.Bind = Conf->ReadValue("link", "bind", j);
 499                 L.Hidden = Conf->ReadFlag("link", "hidden", j);
 500
 501                 if ((!L.Hook.empty()) && (hooks.find(L.Hook.c_str()) ==  hooks.end()))
 502                 {
 503                         ServerInstance->Log(DEFAULT,"m_spanningtree: WARNING: Can't find transport type '%s' for link '%s' - maybe you forgot to load it BEFORE m_spanningtree in your config file? Skipping <link> tag completely.",
 504                         L.Hook.c_str(), L.Name.c_str());
 505                         continue;
 506
 507                 }
 508
 509                 L.NextConnectTime = time(NULL) + L.AutoConnect;
 510                 /* Bugfix by brain, do not allow people to enter bad configurations */
 511                 if (L.Name != ServerInstance->Config->ServerName)
 512                 {
 513                         if ((L.IPAddr != "") && (L.RecvPass != "") && (L.SendPass != "") && (L.Name != "") && (L.Port))
 514                         {
 515                                 ValidIPs.push_back(L.IPAddr);
 516
 517                                 if (Allow.length())
 518                                         ValidIPs.push_back(Allow);
 519
 520                                 /* Needs resolving */
 521                                 bool ipvalid = true;
 522                                 QueryType start_type = DNS_QUERY_A;
 523 #ifdef IPV6
 524                                 start_type = DNS_QUERY_AAAA;
 525                                 if (strchr(L.IPAddr.c_str(),':'))
 526                                 {
 527                                         in6_addr n;
 528                                         if (inet_pton(AF_INET6, L.IPAddr.c_str(), &n) < 1)
 529                                                 ipvalid = false;
 530                                 }
 531                                 else
 532                                 {
 533                                         in_addr n;
 534                                         if (inet_aton(L.IPAddr.c_str(),&n) < 1)
 535                                                 ipvalid = false;
 536                                 }
 537 #else
 538                                 in_addr n;
 539                                 if (inet_aton(L.IPAddr.c_str(),&n) < 1)
 540                                         ipvalid = false;
 541 #endif
 542
 543                                 if (!ipvalid)
 544                                 {
 545                                         try
 546                                         {
 547                                                 bool cached;
 548                                                 SecurityIPResolver* sr = new SecurityIPResolver((Module*)this->Creator, this, ServerInstance, L.IPAddr, L, cached, start_type);
 549                                                 ServerInstance->AddResolver(sr, cached);
 550                                         }
 551                                         catch (ModuleException& e)
 552                                         {
 553                                         }
 554                                 }
 555
 556                                 LinkBlocks.push_back(L);
 557                         }
 558                         else
 559                         {
 560                                 if (L.IPAddr == "")
 561                                 {
 562                                         ServerInstance->Log(DEFAULT,"Invalid configuration for server '%s', IP address not defined!",L.Name.c_str());
 563                                 }
 564                                 else if (L.RecvPass == "")
 565                                 {
 566                                         ServerInstance->Log(DEFAULT,"Invalid configuration for server '%s', recvpass not defined!",L.Name.c_str());
 567                                 }
 568                                 else if (L.SendPass == "")
 569                                 {
 570                                         ServerInstance->Log(DEFAULT,"Invalid configuration for server '%s', sendpass not defined!",L.Name.c_str());
 571                                 }
 572                                 else if (L.Name == "")
 573                                 {
 574                                         ServerInstance->Log(DEFAULT,"Invalid configuration, link tag without a name!");
 575                                 }
 576                                 else if (!L.Port)
 577                                 {
 578                                         ServerInstance->Log(DEFAULT,"Invalid configuration for server '%s', no port specified!",L.Name.c_str());
 579                                 }
 580                         }
 581                 }
 582                 else
 583                 {
 584                         ServerInstance->Log(DEFAULT,"Invalid configuration for server '%s', link tag has the same server name as the local server!",L.Name.c_str());
 585                 }
 586         }
 587         DELETE(Conf);
 588 }
 589
 590 void SpanningTreeUtilities::DoFailOver(Link* x)
 591 {
 592         if (x->FailOver.length())
 593         {
 594                 if (x->FailOver == x->Name)
 595                 {
 596                         ServerInstance->SNO->WriteToSnoMask('l',"FAILOVER: Some muppet configured the failover for server \002%s\002 to point at itself. Not following it!", x->Name.c_str());
 597                         return;
 598                 }
 599                 Link* TryThisOne = this->FindLink(x->FailOver.c_str());
 600                 if (TryThisOne)
 601                 {
 602                         ServerInstance->SNO->WriteToSnoMask('l',"FAILOVER: Trying failover link for \002%s\002: \002%s\002...", x->Name.c_str(), TryThisOne->Name.c_str());
 603                         Creator->ConnectServer(TryThisOne);
 604                 }
 605                 else
 606                 {
 607                         ServerInstance->SNO->WriteToSnoMask('l',"FAILOVER: Invalid failover server specified for server \002%s\002, will not follow!", x->Name.c_str());
 608                 }
 609         }
 610 }
 611
 612 Link* SpanningTreeUtilities::FindLink(const std::string& name)
 613 {
 614         for (std::vector<Link>::iterator x = LinkBlocks.begin(); x < LinkBlocks.end(); x++)
 615         {
 616                 if (ServerInstance->MatchText(x->Name.c_str(), name.c_str()))
 617                 {
 618                         return &(*x);
 619                 }
 620         }
 621         return NULL;
 622 }
 623