src/modules/m_cgiirc.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2007-2008 John Brooks <john.brooks@dereferenced.net>
   6  *   Copyright (C) 2008 Pippijn van Steenhoven <pip88nl@gmail.com>
   7  *   Copyright (C) 2006-2008 Craig Edwards <craigedwards@brainbox.cc>
   8  *   Copyright (C) 2007 Robin Burchell <robin+git@viroteck.net>
   9  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
  10  *   Copyright (C) 2006 Oliver Lupton <oliverlupton@gmail.com>
  11  *
  12  * This file is part of InspIRCd.  InspIRCd is free software: you can
  13  * redistribute it and/or modify it under the terms of the GNU General Public
  14  * License as published by the Free Software Foundation, version 2.
  15  *
  16  * This program is distributed in the hope that it will be useful, but WITHOUT
  17  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  18  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  19  * details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23  */
  24
  25
  26 #include "inspircd.h"
  27 #include "modules/ssl.h"
  28 #include "modules/webirc.h"
  29 #include "modules/whois.h"
  30
  31 enum
  32 {
  33         // InspIRCd-specific.
  34         RPL_WHOISGATEWAY = 350
  35 };
  36
  37 // We need this method up here so that it can be accessed from anywhere
  38 static void ChangeIP(LocalUser* user, const irc::sockets::sockaddrs& sa)
  39 {
  40         // Set the users IP address and make sure they are in the right clone pool.
  41         ServerInstance->Users->RemoveCloneCounts(user);
  42         user->SetClientIP(sa);
  43         ServerInstance->Users->AddClone(user);
  44         if (user->quitting)
  45                 return;
  46
  47         // Recheck the connect class.
  48         user->MyClass = NULL;
  49         user->SetClass();
  50         user->CheckClass();
  51         if (user->quitting)
  52                 return;
  53
  54         // Check if this user matches any XLines.
  55         user->CheckLines(true);
  56         if (user->quitting)
  57                 return;
  58 }
  59
  60 // Encapsulates information about an ident host.
  61 class IdentHost
  62 {
  63  private:
  64         std::string hostmask;
  65         std::string newident;
  66
  67  public:
  68         IdentHost(const std::string& mask, const std::string& ident)
  69                 : hostmask(mask)
  70                 , newident(ident)
  71         {
  72         }
  73
  74         const std::string& GetIdent() const
  75         {
  76                 return newident;
  77         }
  78
  79         bool Matches(LocalUser* user) const
  80         {
  81                 if (!InspIRCd::Match(user->GetRealHost(), hostmask, ascii_case_insensitive_map))
  82                         return false;
  83
  84                 return InspIRCd::MatchCIDR(user->GetIPString(), hostmask, ascii_case_insensitive_map);
  85         }
  86 };
  87
  88 // Encapsulates information about a WebIRC host.
  89 class WebIRCHost
  90 {
  91  private:
  92         std::string hostmask;
  93         std::string fingerprint;
  94         std::string password;
  95         std::string passhash;
  96
  97  public:
  98         WebIRCHost(const std::string& mask, const std::string& fp, const std::string& pass, const std::string& hash)
  99                 : hostmask(mask)
 100                 , fingerprint(fp)
 101                 , password(pass)
 102                 , passhash(hash)
 103         {
 104         }
 105
 106         bool Matches(LocalUser* user, const std::string& pass, UserCertificateAPI& sslapi) const
 107         {
 108                 // Did the user send a valid password?
 109                 if (!password.empty() && !ServerInstance->PassCompare(user, password, pass, passhash))
 110                         return false;
 111
 112                 // Does the user have a valid fingerprint?
 113                 const std::string fp = sslapi ? sslapi->GetFingerprint(user) : "";
 114                 if (!fingerprint.empty() && !InspIRCd::TimingSafeCompare(fp, fingerprint))
 115                         return false;
 116
 117                 // Does the user's hostname match our hostmask?
 118                 if (InspIRCd::Match(user->GetRealHost(), hostmask, ascii_case_insensitive_map))
 119                         return true;
 120
 121                 // Does the user's IP address match our hostmask?
 122                 return InspIRCd::MatchCIDR(user->GetIPString(), hostmask, ascii_case_insensitive_map);
 123         }
 124 };
 125
 126 /*
 127  * WEBIRC
 128  *  This is used for the webirc method of CGIIRC auth, and is (really) the best way to do these things.
 129  *  Syntax: WEBIRC password gateway hostname ip
 130  *  Where password is a shared key, gateway is the name of the WebIRC gateway and version (e.g. cgiirc), hostname
 131  *  is the resolved host of the client issuing the command and IP is the real IP of the client.
 132  *
 133  * How it works:
 134  *  To tie in with the rest of cgiirc module, and to avoid race conditions, /webirc is only processed locally
 135  *  and simply sets metadata on the user, which is later decoded on full connect to give something meaningful.
 136  */
 137 class CommandWebIRC : public SplitCommand
 138 {
 139  public:
 140         std::vector<WebIRCHost> hosts;
 141         bool notify;
 142         StringExtItem gateway;
 143         StringExtItem realhost;
 144         StringExtItem realip;
 145         UserCertificateAPI sslapi;
 146         Events::ModuleEventProvider webircevprov;
 147
 148         CommandWebIRC(Module* Creator)
 149                 : SplitCommand(Creator, "WEBIRC", 4)
 150                 , gateway("cgiirc_gateway", ExtensionItem::EXT_USER, Creator)
 151                 , realhost("cgiirc_realhost", ExtensionItem::EXT_USER, Creator)
 152                 , realip("cgiirc_realip", ExtensionItem::EXT_USER, Creator)
 153                 , sslapi(Creator)
 154                 , webircevprov(Creator, "event/webirc")
 155         {
 156                 allow_empty_last_param = false;
 157                 works_before_reg = true;
 158                 this->syntax = "<password> <gateway> <hostname> <ip> [flags]";
 159         }
 160
 161         CmdResult HandleLocal(LocalUser* user, const Params& parameters) CXX11_OVERRIDE
 162         {
 163                 if (user->registered == REG_ALL || realhost.get(user))
 164                         return CMD_FAILURE;
 165
 166                 for (std::vector<WebIRCHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 167                 {
 168                         // If we don't match the host then skip to the next host.
 169                         if (!iter->Matches(user, parameters[0], sslapi))
 170                                 continue;
 171
 172                         irc::sockets::sockaddrs ipaddr;
 173                         if (!irc::sockets::aptosa(parameters[3], user->client_sa.port(), ipaddr))
 174                         {
 175                                 WriteLog("Connecting user %s (%s) tried to use WEBIRC but gave an invalid IP address.",
 176                                         user->uuid.c_str(), user->GetIPString().c_str());
 177                                 ServerInstance->Users->QuitUser(user, "WEBIRC: IP address is invalid: " + parameters[3]);
 178                                 return CMD_FAILURE;
 179                         }
 180
 181                         // The user matched a WebIRC block!
 182                         gateway.set(user, parameters[1]);
 183                         realhost.set(user, user->GetRealHost());
 184                         realip.set(user, user->GetIPString());
 185
 186                         WriteLog("Connecting user %s is using a WebIRC gateway; changing their IP from %s to %s.",
 187                                 user->uuid.c_str(), user->GetIPString().c_str(), parameters[3].c_str());
 188
 189                         // If we have custom flags then deal with them.
 190                         WebIRC::FlagMap flags;
 191                         const bool hasflags = (parameters.size() > 4);
 192                         if (hasflags)
 193                         {
 194                                 // Parse the flags.
 195                                 irc::spacesepstream flagstream(parameters[4]);
 196                                 for (std::string flag; flagstream.GetToken(flag); )
 197                                 {
 198                                         // Does this flag have a value?
 199                                         const size_t separator = flag.find('=');
 200                                         if (separator == std::string::npos)
 201                                         {
 202                                                 flags[flag];
 203                                                 continue;
 204                                         }
 205
 206                                         // The flag has a value!
 207                                         const std::string key = flag.substr(0, separator);
 208                                         const std::string value = flag.substr(separator + 1);
 209                                         flags[key] = value;
 210                                 }
 211                         }
 212
 213                         // Inform modules about the WebIRC attempt.
 214                         FOREACH_MOD_CUSTOM(webircevprov, WebIRC::EventListener, OnWebIRCAuth, (user, (hasflags ? &flags : NULL)));
 215
 216                         // Set the IP address sent via WEBIRC. We ignore the hostname and lookup
 217                         // instead do our own DNS lookups because of unreliable gateways.
 218                         ChangeIP(user, ipaddr);
 219                         return CMD_SUCCESS;
 220                 }
 221
 222                 WriteLog("Connecting user %s (%s) tried to use WEBIRC but didn't match any configured WebIRC hosts.",
 223                         user->uuid.c_str(), user->GetIPString().c_str());
 224                 ServerInstance->Users->QuitUser(user, "WEBIRC: you don't match any configured WebIRC hosts.");
 225                 return CMD_FAILURE;
 226         }
 227
 228         void WriteLog(const char* message, ...) CUSTOM_PRINTF(2, 3)
 229         {
 230                 std::string buffer;
 231                 VAFORMAT(buffer, message, message);
 232
 233                 // If we are sending a snotice then the message will already be
 234                 // written to the logfile.
 235                 if (notify)
 236                         ServerInstance->SNO->WriteGlobalSno('w', buffer);
 237                 else
 238                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, buffer);
 239         }
 240 };
 241
 242 class ModuleCgiIRC
 243         : public Module
 244         , public WebIRC::EventListener
 245         , public Whois::EventListener
 246 {
 247  private:
 248         CommandWebIRC cmd;
 249         std::vector<IdentHost> hosts;
 250
 251         static bool ParseIdent(LocalUser* user, irc::sockets::sockaddrs& out)
 252         {
 253                 const char* ident = NULL;
 254                 if (user->ident.length() == 8)
 255                 {
 256                         // The ident is an IPv4 address encoded in hexadecimal with two characters
 257                         // per address segment.
 258                         ident = user->ident.c_str();
 259                 }
 260                 else if (user->ident.length() == 9 && user->ident[0] == '~')
 261                 {
 262                         // The same as above but m_ident got to this user before we did. Strip the
 263                         // ident prefix and continue as normal.
 264                         ident = user->ident.c_str() + 1;
 265                 }
 266                 else
 267                 {
 268                         // The user either does not have an IPv4 in their ident or the gateway server
 269                         // is also running an identd. In the latter case there isn't really a lot we
 270                         // can do so we just assume that the client in question is not connecting via
 271                         // an ident gateway.
 272                         return false;
 273                 }
 274
 275                 // Try to convert the IP address to a string. If this fails then the user
 276                 // does not have an IPv4 address in their ident.
 277                 errno = 0;
 278                 unsigned long address = strtoul(ident, NULL, 16);
 279                 if (errno)
 280                         return false;
 281
 282                 out.in4.sin_family = AF_INET;
 283                 out.in4.sin_addr.s_addr = htonl(address);
 284                 return true;
 285         }
 286
 287  public:
 288         ModuleCgiIRC()
 289                 : WebIRC::EventListener(this)
 290                 , Whois::EventListener(this)
 291                 , cmd(this)
 292         {
 293         }
 294
 295         void init() CXX11_OVERRIDE
 296         {
 297                 ServerInstance->SNO->EnableSnomask('w', "CGIIRC");
 298         }
 299
 300         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 301         {
 302                 std::vector<IdentHost> identhosts;
 303                 std::vector<WebIRCHost> webirchosts;
 304
 305                 ConfigTagList tags = ServerInstance->Config->ConfTags("cgihost");
 306                 for (ConfigIter i = tags.first; i != tags.second; ++i)
 307                 {
 308                         ConfigTag* tag = i->second;
 309
 310                         // Ensure that we have the <cgihost:mask> parameter.
 311                         const std::string mask = tag->getString("mask");
 312                         if (mask.empty())
 313                                 throw ModuleException("<cgihost:mask> is a mandatory field, at " + tag->getTagLocation());
 314
 315                         // Determine what lookup type this host uses.
 316                         const std::string type = tag->getString("type");
 317                         if (stdalgo::string::equalsci(type, "ident"))
 318                         {
 319                                 // The IP address should be looked up from the hex IP address.
 320                                 const std::string newident = tag->getString("newident", "gateway", ServerInstance->IsIdent);
 321                                 identhosts.push_back(IdentHost(mask, newident));
 322                         }
 323                         else if (stdalgo::string::equalsci(type, "webirc"))
 324                         {
 325                                 // The IP address will be received via the WEBIRC command.
 326                                 const std::string fingerprint = tag->getString("fingerprint");
 327                                 const std::string password = tag->getString("password");
 328
 329                                 // WebIRC blocks require a password.
 330                                 if (fingerprint.empty() && password.empty())
 331                                         throw ModuleException("When using <cgihost type=\"webirc\"> either the fingerprint or password field is required, at " + tag->getTagLocation());
 332
 333                                 webirchosts.push_back(WebIRCHost(mask, fingerprint, password, tag->getString("hash")));
 334                         }
 335                         else
 336                         {
 337                                 throw ModuleException(type + " is an invalid <cgihost:mask> type, at " + tag->getTagLocation());
 338                         }
 339                 }
 340
 341                 // The host configuration was valid so we can apply it.
 342                 hosts.swap(identhosts);
 343                 cmd.hosts.swap(webirchosts);
 344
 345                 // Do we send an oper notice when a m_cgiirc client has their IP changed?
 346                 cmd.notify = ServerInstance->Config->ConfValue("cgiirc")->getBool("opernotice", true);
 347         }
 348
 349         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE
 350         {
 351                 // If <connect:webirc> is not set then we have nothing to do.
 352                 const std::string webirc = myclass->config->getString("webirc");
 353                 if (webirc.empty())
 354                         return MOD_RES_PASSTHRU;
 355
 356                 // If the user is not connecting via a WebIRC gateway then they
 357                 // cannot match this connect class.
 358                 const std::string* gateway = cmd.gateway.get(user);
 359                 if (!gateway)
 360                         return MOD_RES_DENY;
 361
 362                 // If the gateway matches the <connect:webirc> constraint then
 363                 // allow the check to continue. Otherwise, reject it.
 364                 return InspIRCd::Match(*gateway, webirc) ? MOD_RES_PASSTHRU : MOD_RES_DENY;
 365         }
 366
 367         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
 368         {
 369                 // There is no need to check for gateways if one is already being used.
 370                 if (cmd.realhost.get(user))
 371                         return MOD_RES_PASSTHRU;
 372
 373                 for (std::vector<IdentHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 374                 {
 375                         // If we don't match the host then skip to the next host.
 376                         if (!iter->Matches(user))
 377                                 continue;
 378
 379                         // We have matched an <cgihost> block! Try to parse the encoded IPv4 address
 380                         // out of the ident.
 381                         irc::sockets::sockaddrs address(user->client_sa);
 382                         if (!ParseIdent(user, address))
 383                                 return MOD_RES_PASSTHRU;
 384
 385                         // Store the hostname and IP of the gateway for later use.
 386                         cmd.realhost.set(user, user->GetRealHost());
 387                         cmd.realip.set(user, user->GetIPString());
 388
 389                         const std::string& newident = iter->GetIdent();
 390                         cmd.WriteLog("Connecting user %s is using an ident gateway; changing their IP from %s to %s and their ident from %s to %s.",
 391                                 user->uuid.c_str(), user->GetIPString().c_str(), address.addr().c_str(), user->ident.c_str(), newident.c_str());
 392
 393                         user->ChangeIdent(newident);
 394                         ChangeIP(user, address);
 395                         break;
 396                 }
 397                 return MOD_RES_PASSTHRU;
 398         }
 399
 400         void OnWebIRCAuth(LocalUser* user, const WebIRC::FlagMap* flags) CXX11_OVERRIDE
 401         {
 402                 // We are only interested in connection flags. If none have been
 403                 // given then we have nothing to do.
 404                 if (!flags)
 405                         return;
 406
 407                 WebIRC::FlagMap::const_iterator cport = flags->find("remote-port");
 408                 if (cport != flags->end())
 409                 {
 410                         // If we can't parse the port then just give up.
 411                         uint16_t port = ConvToNum<uint16_t>(cport->second);
 412                         if (port)
 413                         {
 414                                 switch (user->client_sa.family())
 415                                 {
 416                                         case AF_INET:
 417                                                 user->client_sa.in4.sin_port = htons(port);
 418                                                 break;
 419
 420                                         case AF_INET6:
 421                                                 user->client_sa.in6.sin6_port = htons(port);
 422                                                 break;
 423
 424                                         default:
 425                                                 // If we have reached this point then we have encountered a bug.
 426                                                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "BUG: OnWebIRCAuth(%s): socket type %d is unknown!",
 427                                                         user->uuid.c_str(), user->client_sa.family());
 428                                                 return;
 429                                 }
 430                         }
 431                 }
 432
 433                 WebIRC::FlagMap::const_iterator sport = flags->find("local-port");
 434                 if (sport != flags->end())
 435                 {
 436                         // If we can't parse the port then just give up.
 437                         uint16_t port = ConvToNum<uint16_t>(sport->second);
 438                         if (port)
 439                         {
 440                                 switch (user->server_sa.family())
 441                                 {
 442                                         case AF_INET:
 443                                                 user->server_sa.in4.sin_port = htons(port);
 444                                                 break;
 445
 446                                         case AF_INET6:
 447                                                 user->server_sa.in6.sin6_port = htons(port);
 448                                                 break;
 449
 450                                         default:
 451                                                 // If we have reached this point then we have encountered a bug.
 452                                                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "BUG: OnWebIRCAuth(%s): socket type %d is unknown!",
 453                                                         user->uuid.c_str(), user->server_sa.family());
 454                                                 return;
 455                                 }
 456                         }
 457                 }
 458         }
 459
 460         void OnWhois(Whois::Context& whois) CXX11_OVERRIDE
 461         {
 462                 if (!whois.IsSelfWhois() && !whois.GetSource()->HasPrivPermission("users/auspex"))
 463                         return;
 464
 465                 // If these fields are not set then the client is not using a gateway.
 466                 const std::string* realhost = cmd.realhost.get(whois.GetTarget());
 467                 const std::string* realip = cmd.realip.get(whois.GetTarget());
 468                 if (!realhost || !realip)
 469                         return;
 470
 471                 const std::string* gateway = cmd.gateway.get(whois.GetTarget());
 472                 if (gateway)
 473                         whois.SendLine(RPL_WHOISGATEWAY, *realhost, *realip, "is connected via the " + *gateway + " WebIRC gateway");
 474                 else
 475                         whois.SendLine(RPL_WHOISGATEWAY, *realhost, *realip, "is connected via an ident gateway");
 476         }
 477
 478         Version GetVersion() CXX11_OVERRIDE
 479         {
 480                 return Version("Enables forwarding the real IP address of a user from a gateway to the IRC server", VF_VENDOR);
 481         }
 482 };
 483
 484 MODULE_INIT(ModuleCgiIRC)