src/modules/m_cgiirc.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2019 linuxdaemon <linuxdaemon.irc@gmail.com>
   5  *   Copyright (C) 2014 md_5 <git@md-5.net>
   6  *   Copyright (C) 2014 Googolplexed <googol@googolplexed.net>
   7  *   Copyright (C) 2013, 2017-2018, 2020 Sadie Powell <sadie@witchery.services>
   8  *   Copyright (C) 2013 Adam <Adam@anope.org>
   9  *   Copyright (C) 2012-2013, 2015 Attila Molnar <attilamolnar@hush.com>
  10  *   Copyright (C) 2012, 2019 Robby <robby@chatbelgie.be>
  11  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
  12  *   Copyright (C) 2009 Uli Schlachter <psychon@inspircd.org>
  13  *   Copyright (C) 2007-2009 Robin Burchell <robin+git@viroteck.net>
  14  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
  15  *   Copyright (C) 2006-2007, 2010 Craig Edwards <brain@inspircd.org>
  16  *
  17  * This file is part of InspIRCd.  InspIRCd is free software: you can
  18  * redistribute it and/or modify it under the terms of the GNU General Public
  19  * License as published by the Free Software Foundation, version 2.
  20  *
  21  * This program is distributed in the hope that it will be useful, but WITHOUT
  22  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  23  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  24  * details.
  25  *
  26  * You should have received a copy of the GNU General Public License
  27  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  28  */
  29
  30
  31 #include "inspircd.h"
  32 #include "modules/ssl.h"
  33 #include "modules/webirc.h"
  34 #include "modules/whois.h"
  35
  36 enum
  37 {
  38         // InspIRCd-specific.
  39         RPL_WHOISGATEWAY = 350
  40 };
  41
  42 // One or more hostmask globs or CIDR ranges.
  43 typedef std::vector<std::string> MaskList;
  44
  45 // Encapsulates information about an ident host.
  46 class IdentHost
  47 {
  48  private:
  49         MaskList hostmasks;
  50         std::string newident;
  51
  52  public:
  53         IdentHost(const MaskList& masks, const std::string& ident)
  54                 : hostmasks(masks)
  55                 , newident(ident)
  56         {
  57         }
  58
  59         const std::string& GetIdent() const
  60         {
  61                 return newident;
  62         }
  63
  64         bool Matches(LocalUser* user) const
  65         {
  66                 for (MaskList::const_iterator iter = hostmasks.begin(); iter != hostmasks.end(); ++iter)
  67                 {
  68                         // Does the user's hostname match this hostmask?
  69                         if (InspIRCd::Match(user->GetRealHost(), *iter, ascii_case_insensitive_map))
  70                                 return true;
  71
  72                         // Does the user's IP address match this hostmask?
  73                         if (InspIRCd::MatchCIDR(user->GetIPString(), *iter, ascii_case_insensitive_map))
  74                                 return true;
  75                 }
  76
  77                 // The user didn't match any hostmasks.
  78                 return false;
  79         }
  80 };
  81
  82 // Encapsulates information about a WebIRC host.
  83 class WebIRCHost
  84 {
  85  private:
  86         MaskList hostmasks;
  87         std::string fingerprint;
  88         std::string password;
  89         std::string passhash;
  90
  91  public:
  92         WebIRCHost(const MaskList& masks, const std::string& fp, const std::string& pass, const std::string& hash)
  93                 : hostmasks(masks)
  94                 , fingerprint(fp)
  95                 , password(pass)
  96                 , passhash(hash)
  97         {
  98         }
  99
 100         bool Matches(LocalUser* user, const std::string& pass, UserCertificateAPI& sslapi) const
 101         {
 102                 // Did the user send a valid password?
 103                 if (!password.empty() && !ServerInstance->PassCompare(user, password, pass, passhash))
 104                         return false;
 105
 106                 // Does the user have a valid fingerprint?
 107                 const std::string fp = sslapi ? sslapi->GetFingerprint(user) : "";
 108                 if (!fingerprint.empty() && !InspIRCd::TimingSafeCompare(fp, fingerprint))
 109                         return false;
 110
 111                 for (MaskList::const_iterator iter = hostmasks.begin(); iter != hostmasks.end(); ++iter)
 112                 {
 113                         // Does the user's hostname match this hostmask?
 114                         if (InspIRCd::Match(user->GetRealHost(), *iter, ascii_case_insensitive_map))
 115                                 return true;
 116
 117                         // Does the user's IP address match this hostmask?
 118                         if (InspIRCd::MatchCIDR(user->GetIPString(), *iter, ascii_case_insensitive_map))
 119                                 return true;
 120                 }
 121
 122                 // The user didn't match any hostmasks.
 123                 return false;
 124         }
 125 };
 126
 127 class CommandWebIRC : public SplitCommand
 128 {
 129  public:
 130         std::vector<WebIRCHost> hosts;
 131         bool notify;
 132         StringExtItem gateway;
 133         StringExtItem realhost;
 134         StringExtItem realip;
 135         UserCertificateAPI sslapi;
 136         Events::ModuleEventProvider webircevprov;
 137
 138         CommandWebIRC(Module* Creator)
 139                 : SplitCommand(Creator, "WEBIRC", 4)
 140                 , gateway("cgiirc_gateway", ExtensionItem::EXT_USER, Creator)
 141                 , realhost("cgiirc_realhost", ExtensionItem::EXT_USER, Creator)
 142                 , realip("cgiirc_realip", ExtensionItem::EXT_USER, Creator)
 143                 , sslapi(Creator)
 144                 , webircevprov(Creator, "event/webirc")
 145         {
 146                 allow_empty_last_param = false;
 147                 works_before_reg = true;
 148                 this->syntax = "<password> <gateway> <hostname> <ip> [<flags>]";
 149         }
 150
 151         CmdResult HandleLocal(LocalUser* user, const Params& parameters) CXX11_OVERRIDE
 152         {
 153                 if (user->registered == REG_ALL || realhost.get(user))
 154                         return CMD_FAILURE;
 155
 156                 for (std::vector<WebIRCHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 157                 {
 158                         // If we don't match the host then skip to the next host.
 159                         if (!iter->Matches(user, parameters[0], sslapi))
 160                                 continue;
 161
 162                         irc::sockets::sockaddrs ipaddr;
 163                         if (!irc::sockets::aptosa(parameters[3], user->client_sa.port(), ipaddr))
 164                         {
 165                                 WriteLog("Connecting user %s (%s) tried to use WEBIRC but gave an invalid IP address.",
 166                                         user->uuid.c_str(), user->GetIPString().c_str());
 167                                 ServerInstance->Users->QuitUser(user, "WEBIRC: IP address is invalid: " + parameters[3]);
 168                                 return CMD_FAILURE;
 169                         }
 170
 171                         // The user matched a WebIRC block!
 172                         gateway.set(user, parameters[1]);
 173                         realhost.set(user, user->GetRealHost());
 174                         realip.set(user, user->GetIPString());
 175
 176                         WriteLog("Connecting user %s is using a WebIRC gateway; changing their IP from %s to %s.",
 177                                 user->uuid.c_str(), user->GetIPString().c_str(), parameters[3].c_str());
 178
 179                         // If we have custom flags then deal with them.
 180                         WebIRC::FlagMap flags;
 181                         const bool hasflags = (parameters.size() > 4);
 182                         if (hasflags)
 183                         {
 184                                 // Parse the flags.
 185                                 irc::spacesepstream flagstream(parameters[4]);
 186                                 for (std::string flag; flagstream.GetToken(flag); )
 187                                 {
 188                                         // Does this flag have a value?
 189                                         const size_t separator = flag.find('=');
 190                                         if (separator == std::string::npos)
 191                                         {
 192                                                 flags[flag];
 193                                                 continue;
 194                                         }
 195
 196                                         // The flag has a value!
 197                                         const std::string key = flag.substr(0, separator);
 198                                         const std::string value = flag.substr(separator + 1);
 199                                         flags[key] = value;
 200                                 }
 201                         }
 202
 203                         // Inform modules about the WebIRC attempt.
 204                         FOREACH_MOD_CUSTOM(webircevprov, WebIRC::EventListener, OnWebIRCAuth, (user, (hasflags ? &flags : NULL)));
 205
 206                         // Set the IP address sent via WEBIRC. We ignore the hostname and lookup
 207                         // instead do our own DNS lookups because of unreliable gateways.
 208                         user->SetClientIP(ipaddr);
 209                         return CMD_SUCCESS;
 210                 }
 211
 212                 WriteLog("Connecting user %s (%s) tried to use WEBIRC but didn't match any configured WebIRC hosts.",
 213                         user->uuid.c_str(), user->GetIPString().c_str());
 214                 ServerInstance->Users->QuitUser(user, "WEBIRC: you don't match any configured WebIRC hosts.");
 215                 return CMD_FAILURE;
 216         }
 217
 218         void WriteLog(const char* message, ...) CUSTOM_PRINTF(2, 3)
 219         {
 220                 std::string buffer;
 221                 VAFORMAT(buffer, message, message);
 222
 223                 // If we are sending a snotice then the message will already be
 224                 // written to the logfile.
 225                 if (notify)
 226                         ServerInstance->SNO->WriteGlobalSno('w', buffer);
 227                 else
 228                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, buffer);
 229         }
 230 };
 231
 232 class ModuleCgiIRC
 233         : public Module
 234         , public WebIRC::EventListener
 235         , public Whois::EventListener
 236 {
 237  private:
 238         CommandWebIRC cmd;
 239         std::vector<IdentHost> hosts;
 240
 241         static bool ParseIdent(LocalUser* user, irc::sockets::sockaddrs& out)
 242         {
 243                 const char* ident = NULL;
 244                 if (user->ident.length() == 8)
 245                 {
 246                         // The ident is an IPv4 address encoded in hexadecimal with two characters
 247                         // per address segment.
 248                         ident = user->ident.c_str();
 249                 }
 250                 else if (user->ident.length() == 9 && user->ident[0] == '~')
 251                 {
 252                         // The same as above but m_ident got to this user before we did. Strip the
 253                         // ident prefix and continue as normal.
 254                         ident = user->ident.c_str() + 1;
 255                 }
 256                 else
 257                 {
 258                         // The user either does not have an IPv4 in their ident or the gateway server
 259                         // is also running an identd. In the latter case there isn't really a lot we
 260                         // can do so we just assume that the client in question is not connecting via
 261                         // an ident gateway.
 262                         return false;
 263                 }
 264
 265                 // Try to convert the IP address to a string. If this fails then the user
 266                 // does not have an IPv4 address in their ident.
 267                 errno = 0;
 268                 unsigned long address = strtoul(ident, NULL, 16);
 269                 if (errno)
 270                         return false;
 271
 272                 out.in4.sin_family = AF_INET;
 273                 out.in4.sin_addr.s_addr = htonl(address);
 274                 return true;
 275         }
 276
 277  public:
 278         ModuleCgiIRC()
 279                 : WebIRC::EventListener(this)
 280                 , Whois::EventListener(this)
 281                 , cmd(this)
 282         {
 283         }
 284
 285         void init() CXX11_OVERRIDE
 286         {
 287                 ServerInstance->SNO->EnableSnomask('w', "CGIIRC");
 288         }
 289
 290         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 291         {
 292                 std::vector<IdentHost> identhosts;
 293                 std::vector<WebIRCHost> webirchosts;
 294
 295                 ConfigTagList tags = ServerInstance->Config->ConfTags("cgihost");
 296                 for (ConfigIter i = tags.first; i != tags.second; ++i)
 297                 {
 298                         ConfigTag* tag = i->second;
 299
 300                         MaskList masks;
 301                         irc::spacesepstream maskstream(tag->getString("mask"));
 302                         for (std::string mask; maskstream.GetToken(mask); )
 303                                 masks.push_back(mask);
 304
 305                         // Ensure that we have the <cgihost:mask> parameter.
 306                         if (masks.empty())
 307                                 throw ModuleException("<cgihost:mask> is a mandatory field, at " + tag->getTagLocation());
 308
 309                         // Determine what lookup type this host uses.
 310                         const std::string type = tag->getString("type");
 311                         if (stdalgo::string::equalsci(type, "ident"))
 312                         {
 313                                 // The IP address should be looked up from the hex IP address.
 314                                 const std::string newident = tag->getString("newident", "gateway", ServerInstance->IsIdent);
 315                                 identhosts.push_back(IdentHost(masks, newident));
 316                         }
 317                         else if (stdalgo::string::equalsci(type, "webirc"))
 318                         {
 319                                 // The IP address will be received via the WEBIRC command.
 320                                 const std::string fingerprint = tag->getString("fingerprint");
 321                                 const std::string password = tag->getString("password");
 322                                 const std::string passwordhash = tag->getString("hash", "plaintext", 1);
 323
 324                                 // WebIRC blocks require a password.
 325                                 if (fingerprint.empty() && password.empty())
 326                                         throw ModuleException("When using <cgihost type=\"webirc\"> either the fingerprint or password field is required, at " + tag->getTagLocation());
 327
 328                                 if (!password.empty() && stdalgo::string::equalsci(passwordhash, "plaintext"))
 329                                 {
 330                                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "<cgihost> tag at %s contains an plain text password, this is insecure!",
 331                                                 tag->getTagLocation().c_str());
 332                                 }
 333
 334                                 webirchosts.push_back(WebIRCHost(masks, fingerprint, password, passwordhash));
 335                         }
 336                         else
 337                         {
 338                                 throw ModuleException(type + " is an invalid <cgihost:mask> type, at " + tag->getTagLocation());
 339                         }
 340                 }
 341
 342                 // The host configuration was valid so we can apply it.
 343                 hosts.swap(identhosts);
 344                 cmd.hosts.swap(webirchosts);
 345
 346                 // Do we send an oper notice when a m_cgiirc client has their IP changed?
 347                 cmd.notify = ServerInstance->Config->ConfValue("cgiirc")->getBool("opernotice", true);
 348         }
 349
 350         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE
 351         {
 352                 // If <connect:webirc> is not set then we have nothing to do.
 353                 const std::string webirc = myclass->config->getString("webirc");
 354                 if (webirc.empty())
 355                         return MOD_RES_PASSTHRU;
 356
 357                 // If the user is not connecting via a WebIRC gateway then they
 358                 // cannot match this connect class.
 359                 const std::string* gateway = cmd.gateway.get(user);
 360                 if (!gateway)
 361                 {
 362                         ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "The %s connect class is not suitable as it requires a connection via a WebIRC gateway",
 363                                         myclass->GetName().c_str());
 364                         return MOD_RES_DENY;
 365                 }
 366
 367                 // If the gateway matches the <connect:webirc> constraint then
 368                 // allow the check to continue. Otherwise, reject it.
 369                 if (!InspIRCd::Match(*gateway, webirc))
 370                 {
 371                         ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "The %s connect class is not suitable as the WebIRC gateway name (%s) does not match %s",
 372                                         myclass->GetName().c_str(), gateway->c_str(), webirc.c_str());
 373                         return MOD_RES_DENY;
 374                 }
 375
 376                 return MOD_RES_PASSTHRU;
 377         }
 378
 379         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
 380         {
 381                 // There is no need to check for gateways if one is already being used.
 382                 if (cmd.realhost.get(user))
 383                         return MOD_RES_PASSTHRU;
 384
 385                 for (std::vector<IdentHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 386                 {
 387                         // If we don't match the host then skip to the next host.
 388                         if (!iter->Matches(user))
 389                                 continue;
 390
 391                         // We have matched an <cgihost> block! Try to parse the encoded IPv4 address
 392                         // out of the ident.
 393                         irc::sockets::sockaddrs address(user->client_sa);
 394                         if (!ParseIdent(user, address))
 395                                 return MOD_RES_PASSTHRU;
 396
 397                         // Store the hostname and IP of the gateway for later use.
 398                         cmd.realhost.set(user, user->GetRealHost());
 399                         cmd.realip.set(user, user->GetIPString());
 400
 401                         const std::string& newident = iter->GetIdent();
 402                         cmd.WriteLog("Connecting user %s is using an ident gateway; changing their IP from %s to %s and their ident from %s to %s.",
 403                                 user->uuid.c_str(), user->GetIPString().c_str(), address.addr().c_str(), user->ident.c_str(), newident.c_str());
 404
 405                         user->ChangeIdent(newident);
 406                         user->SetClientIP(address);
 407                         break;
 408                 }
 409                 return MOD_RES_PASSTHRU;
 410         }
 411
 412         void OnWebIRCAuth(LocalUser* user, const WebIRC::FlagMap* flags) CXX11_OVERRIDE
 413         {
 414                 // We are only interested in connection flags. If none have been
 415                 // given then we have nothing to do.
 416                 if (!flags)
 417                         return;
 418
 419                 WebIRC::FlagMap::const_iterator cport = flags->find("remote-port");
 420                 if (cport != flags->end())
 421                 {
 422                         // If we can't parse the port then just give up.
 423                         uint16_t port = ConvToNum<uint16_t>(cport->second);
 424                         if (port)
 425                         {
 426                                 switch (user->client_sa.family())
 427                                 {
 428                                         case AF_INET:
 429                                                 user->client_sa.in4.sin_port = htons(port);
 430                                                 break;
 431
 432                                         case AF_INET6:
 433                                                 user->client_sa.in6.sin6_port = htons(port);
 434                                                 break;
 435
 436                                         default:
 437                                                 // If we have reached this point then we have encountered a bug.
 438                                                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "BUG: OnWebIRCAuth(%s): socket type %d is unknown!",
 439                                                         user->uuid.c_str(), user->client_sa.family());
 440                                                 return;
 441                                 }
 442                         }
 443                 }
 444
 445                 WebIRC::FlagMap::const_iterator sport = flags->find("local-port");
 446                 if (sport != flags->end())
 447                 {
 448                         // If we can't parse the port then just give up.
 449                         uint16_t port = ConvToNum<uint16_t>(sport->second);
 450                         if (port)
 451                         {
 452                                 switch (user->server_sa.family())
 453                                 {
 454                                         case AF_INET:
 455                                                 user->server_sa.in4.sin_port = htons(port);
 456                                                 break;
 457
 458                                         case AF_INET6:
 459                                                 user->server_sa.in6.sin6_port = htons(port);
 460                                                 break;
 461
 462                                         default:
 463                                                 // If we have reached this point then we have encountered a bug.
 464                                                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "BUG: OnWebIRCAuth(%s): socket type %d is unknown!",
 465                                                         user->uuid.c_str(), user->server_sa.family());
 466                                                 return;
 467                                 }
 468                         }
 469                 }
 470         }
 471
 472         void OnWhois(Whois::Context& whois) CXX11_OVERRIDE
 473         {
 474                 if (!whois.IsSelfWhois() && !whois.GetSource()->HasPrivPermission("users/auspex"))
 475                         return;
 476
 477                 // If these fields are not set then the client is not using a gateway.
 478                 const std::string* realhost = cmd.realhost.get(whois.GetTarget());
 479                 const std::string* realip = cmd.realip.get(whois.GetTarget());
 480                 if (!realhost || !realip)
 481                         return;
 482
 483                 const std::string* gateway = cmd.gateway.get(whois.GetTarget());
 484                 if (gateway)
 485                         whois.SendLine(RPL_WHOISGATEWAY, *realhost, *realip, "is connected via the " + *gateway + " WebIRC gateway");
 486                 else
 487                         whois.SendLine(RPL_WHOISGATEWAY, *realhost, *realip, "is connected via an ident gateway");
 488         }
 489
 490         Version GetVersion() CXX11_OVERRIDE
 491         {
 492                 return Version("Adds the ability for IRC gateways to forward the real IP address of users connecting through them.", VF_VENDOR);
 493         }
 494 };
 495
 496 MODULE_INIT(ModuleCgiIRC)