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, 2020-2021 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 CommandHexIP : public SplitCommand
 128 {
 129  public:
 130         CommandHexIP(Module* Creator)
 131                 : SplitCommand(Creator, "HEXIP", 1)
 132         {
 133                 allow_empty_last_param = false;
 134                 Penalty = 2;
 135                 syntax = "<hex-ip|raw-ip>";
 136         }
 137
 138         CmdResult HandleLocal(LocalUser* user, const Params& parameters) CXX11_OVERRIDE
 139         {
 140                 irc::sockets::sockaddrs sa;
 141                 if (irc::sockets::aptosa(parameters[0], 0, sa))
 142                 {
 143                         if (sa.family() != AF_INET)
 144                         {
 145                                 user->WriteNotice("*** HEXIP: You can only hex encode an IPv4 address!");
 146                                 return CMD_FAILURE;
 147                         }
 148
 149                         uint32_t addr = sa.in4.sin_addr.s_addr;
 150                         user->WriteNotice(InspIRCd::Format("*** HEXIP: %s encodes to %02x%02x%02x%02x.",
 151                                 sa.addr().c_str(), (addr & 0xFF), ((addr >> 8) & 0xFF), ((addr >> 16) & 0xFF),
 152                                 ((addr >> 24) & 0xFF)));
 153                         return CMD_SUCCESS;
 154                 }
 155
 156                 if (ParseIP(parameters[0], sa))
 157                 {
 158                         user->WriteNotice(InspIRCd::Format("*** HEXIP: %s decodes to %s.",
 159                                 parameters[0].c_str(), sa.addr().c_str()));
 160                         return CMD_SUCCESS;
 161                 }
 162
 163                 user->WriteNotice(InspIRCd::Format("*** HEXIP: %s is not a valid raw or hex encoded IPv4 address.",
 164                         parameters[0].c_str()));
 165                 return CMD_FAILURE;
 166         }
 167
 168         static bool ParseIP(const std::string& in, irc::sockets::sockaddrs& out)
 169         {
 170                 const char* ident = NULL;
 171                 if (in.length() == 8)
 172                 {
 173                         // The ident is an IPv4 address encoded in hexadecimal with two characters
 174                         // per address segment.
 175                         ident = in.c_str();
 176                 }
 177                 else if (in.length() == 9 && in[0] == '~')
 178                 {
 179                         // The same as above but m_ident got to this user before we did. Strip the
 180                         // ident prefix and continue as normal.
 181                         ident = in.c_str() + 1;
 182                 }
 183                 else
 184                 {
 185                         // The user either does not have an IPv4 in their ident or the gateway server
 186                         // is also running an identd. In the latter case there isn't really a lot we
 187                         // can do so we just assume that the client in question is not connecting via
 188                         // an ident gateway.
 189                         return false;
 190                 }
 191
 192                 // Try to convert the IP address to a string. If this fails then the user
 193                 // does not have an IPv4 address in their ident.
 194                 errno = 0;
 195                 unsigned long address = strtoul(ident, NULL, 16);
 196                 if (errno)
 197                         return false;
 198
 199                 out.in4.sin_family = AF_INET;
 200                 out.in4.sin_addr.s_addr = htonl(address);
 201                 return true;
 202         }
 203 };
 204
 205 class CommandWebIRC : public SplitCommand
 206 {
 207  public:
 208         std::vector<WebIRCHost> hosts;
 209         bool notify;
 210         StringExtItem gateway;
 211         StringExtItem realhost;
 212         StringExtItem realip;
 213         UserCertificateAPI sslapi;
 214         Events::ModuleEventProvider webircevprov;
 215
 216         CommandWebIRC(Module* Creator)
 217                 : SplitCommand(Creator, "WEBIRC", 4)
 218                 , gateway("cgiirc_gateway", ExtensionItem::EXT_USER, Creator)
 219                 , realhost("cgiirc_realhost", ExtensionItem::EXT_USER, Creator)
 220                 , realip("cgiirc_realip", ExtensionItem::EXT_USER, Creator)
 221                 , sslapi(Creator)
 222                 , webircevprov(Creator, "event/webirc")
 223         {
 224                 allow_empty_last_param = false;
 225                 works_before_reg = true;
 226                 this->syntax = "<password> <gateway> <hostname> <ip> [<flags>]";
 227         }
 228
 229         CmdResult HandleLocal(LocalUser* user, const Params& parameters) CXX11_OVERRIDE
 230         {
 231                 if (user->registered == REG_ALL || realhost.get(user))
 232                         return CMD_FAILURE;
 233
 234                 for (std::vector<WebIRCHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 235                 {
 236                         // If we don't match the host then skip to the next host.
 237                         if (!iter->Matches(user, parameters[0], sslapi))
 238                                 continue;
 239
 240                         irc::sockets::sockaddrs ipaddr;
 241                         if (!irc::sockets::aptosa(parameters[3], user->client_sa.port(), ipaddr))
 242                         {
 243                                 WriteLog("Connecting user %s (%s) tried to use WEBIRC but gave an invalid IP address.",
 244                                         user->uuid.c_str(), user->GetIPString().c_str());
 245                                 ServerInstance->Users->QuitUser(user, "WEBIRC: IP address is invalid: " + parameters[3]);
 246                                 return CMD_FAILURE;
 247                         }
 248
 249                         // The user matched a WebIRC block!
 250                         gateway.set(user, parameters[1]);
 251                         realhost.set(user, user->GetRealHost());
 252                         realip.set(user, user->GetIPString());
 253
 254                         WriteLog("Connecting user %s is using the %s WebIRC gateway; changing their IP from %s to %s.",
 255                                 user->uuid.c_str(), parameters[1].c_str(),
 256                                 user->GetIPString().c_str(), parameters[3].c_str());
 257
 258                         // If we have custom flags then deal with them.
 259                         WebIRC::FlagMap flags;
 260                         const bool hasflags = (parameters.size() > 4);
 261                         if (hasflags)
 262                         {
 263                                 // Parse the flags.
 264                                 irc::spacesepstream flagstream(parameters[4]);
 265                                 for (std::string flag; flagstream.GetToken(flag); )
 266                                 {
 267                                         // Does this flag have a value?
 268                                         const size_t separator = flag.find('=');
 269                                         if (separator == std::string::npos)
 270                                         {
 271                                                 flags[flag];
 272                                                 continue;
 273                                         }
 274
 275                                         // The flag has a value!
 276                                         const std::string key = flag.substr(0, separator);
 277                                         const std::string value = flag.substr(separator + 1);
 278                                         flags[key] = value;
 279                                 }
 280                         }
 281
 282                         // Inform modules about the WebIRC attempt.
 283                         FOREACH_MOD_CUSTOM(webircevprov, WebIRC::EventListener, OnWebIRCAuth, (user, (hasflags ? &flags : NULL)));
 284
 285                         // Set the IP address sent via WEBIRC. We ignore the hostname and lookup
 286                         // instead do our own DNS lookups because of unreliable gateways.
 287                         user->SetClientIP(ipaddr);
 288                         return CMD_SUCCESS;
 289                 }
 290
 291                 WriteLog("Connecting user %s (%s) tried to use WEBIRC but didn't match any configured WebIRC hosts.",
 292                         user->uuid.c_str(), user->GetIPString().c_str());
 293                 ServerInstance->Users->QuitUser(user, "WEBIRC: you don't match any configured WebIRC hosts.");
 294                 return CMD_FAILURE;
 295         }
 296
 297         void WriteLog(const char* message, ...) CUSTOM_PRINTF(2, 3)
 298         {
 299                 std::string buffer;
 300                 VAFORMAT(buffer, message, message);
 301
 302                 // If we are sending a snotice then the message will already be
 303                 // written to the logfile.
 304                 if (notify)
 305                         ServerInstance->SNO->WriteGlobalSno('w', buffer);
 306                 else
 307                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, buffer);
 308         }
 309 };
 310
 311 class ModuleCgiIRC
 312         : public Module
 313         , public WebIRC::EventListener
 314         , public Whois::EventListener
 315 {
 316  private:
 317         CommandHexIP cmdhexip;
 318         CommandWebIRC cmdwebirc;
 319         std::vector<IdentHost> hosts;
 320
 321  public:
 322         ModuleCgiIRC()
 323                 : WebIRC::EventListener(this)
 324                 , Whois::EventListener(this)
 325                 , cmdhexip(this)
 326                 , cmdwebirc(this)
 327         {
 328         }
 329
 330         void init() CXX11_OVERRIDE
 331         {
 332                 ServerInstance->SNO->EnableSnomask('w', "CGIIRC");
 333         }
 334
 335         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 336         {
 337                 std::vector<IdentHost> identhosts;
 338                 std::vector<WebIRCHost> webirchosts;
 339
 340                 ConfigTagList tags = ServerInstance->Config->ConfTags("cgihost");
 341                 for (ConfigIter i = tags.first; i != tags.second; ++i)
 342                 {
 343                         ConfigTag* tag = i->second;
 344
 345                         MaskList masks;
 346                         irc::spacesepstream maskstream(tag->getString("mask"));
 347                         for (std::string mask; maskstream.GetToken(mask); )
 348                                 masks.push_back(mask);
 349
 350                         // Ensure that we have the <cgihost:mask> parameter.
 351                         if (masks.empty())
 352                                 throw ModuleException("<cgihost:mask> is a mandatory field, at " + tag->getTagLocation());
 353
 354                         // Determine what lookup type this host uses.
 355                         const std::string type = tag->getString("type");
 356                         if (stdalgo::string::equalsci(type, "ident"))
 357                         {
 358                                 // The IP address should be looked up from the hex IP address.
 359                                 const std::string newident = tag->getString("newident", "gateway", ServerInstance->IsIdent);
 360                                 identhosts.push_back(IdentHost(masks, newident));
 361                         }
 362                         else if (stdalgo::string::equalsci(type, "webirc"))
 363                         {
 364                                 // The IP address will be received via the WEBIRC command.
 365                                 const std::string fingerprint = tag->getString("fingerprint");
 366                                 const std::string password = tag->getString("password");
 367                                 const std::string passwordhash = tag->getString("hash", "plaintext", 1);
 368
 369                                 // WebIRC blocks require a password.
 370                                 if (fingerprint.empty() && password.empty())
 371                                         throw ModuleException("When using <cgihost type=\"webirc\"> either the fingerprint or password field is required, at " + tag->getTagLocation());
 372
 373                                 if (!password.empty() && stdalgo::string::equalsci(passwordhash, "plaintext"))
 374                                 {
 375                                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "<cgihost> tag at %s contains an plain text password, this is insecure!",
 376                                                 tag->getTagLocation().c_str());
 377                                 }
 378
 379                                 webirchosts.push_back(WebIRCHost(masks, fingerprint, password, passwordhash));
 380                         }
 381                         else
 382                         {
 383                                 throw ModuleException(type + " is an invalid <cgihost:mask> type, at " + tag->getTagLocation());
 384                         }
 385                 }
 386
 387                 // The host configuration was valid so we can apply it.
 388                 hosts.swap(identhosts);
 389                 cmdwebirc.hosts.swap(webirchosts);
 390
 391                 // Do we send an oper notice when a m_cgiirc client has their IP changed?
 392                 cmdwebirc.notify = ServerInstance->Config->ConfValue("cgiirc")->getBool("opernotice", true);
 393         }
 394
 395         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE
 396         {
 397                 // If <connect:webirc> is not set then we have nothing to do.
 398                 const std::string webirc = myclass->config->getString("webirc");
 399                 if (webirc.empty())
 400                         return MOD_RES_PASSTHRU;
 401
 402                 // If the user is not connecting via a WebIRC gateway then they
 403                 // cannot match this connect class.
 404                 const std::string* gateway = cmdwebirc.gateway.get(user);
 405                 if (!gateway)
 406                 {
 407                         ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "The %s connect class is not suitable as it requires a connection via a WebIRC gateway",
 408                                         myclass->GetName().c_str());
 409                         return MOD_RES_DENY;
 410                 }
 411
 412                 // If the gateway matches the <connect:webirc> constraint then
 413                 // allow the check to continue. Otherwise, reject it.
 414                 if (!InspIRCd::Match(*gateway, webirc))
 415                 {
 416                         ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "The %s connect class is not suitable as the WebIRC gateway name (%s) does not match %s",
 417                                         myclass->GetName().c_str(), gateway->c_str(), webirc.c_str());
 418                         return MOD_RES_DENY;
 419                 }
 420
 421                 return MOD_RES_PASSTHRU;
 422         }
 423
 424         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
 425         {
 426                 // There is no need to check for gateways if one is already being used.
 427                 if (cmdwebirc.realhost.get(user))
 428                         return MOD_RES_PASSTHRU;
 429
 430                 for (std::vector<IdentHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 431                 {
 432                         // If we don't match the host then skip to the next host.
 433                         if (!iter->Matches(user))
 434                                 continue;
 435
 436                         // We have matched an <cgihost> block! Try to parse the encoded IPv4 address
 437                         // out of the ident.
 438                         irc::sockets::sockaddrs address(user->client_sa);
 439                         if (!CommandHexIP::ParseIP(user->ident, address))
 440                                 return MOD_RES_PASSTHRU;
 441
 442                         // Store the hostname and IP of the gateway for later use.
 443                         cmdwebirc.realhost.set(user, user->GetRealHost());
 444                         cmdwebirc.realip.set(user, user->GetIPString());
 445
 446                         const std::string& newident = iter->GetIdent();
 447                         cmdwebirc.WriteLog("Connecting user %s is using an ident gateway; changing their IP from %s to %s and their ident from %s to %s.",
 448                                 user->uuid.c_str(), user->GetIPString().c_str(), address.addr().c_str(), user->ident.c_str(), newident.c_str());
 449
 450                         user->ChangeIdent(newident);
 451                         user->SetClientIP(address);
 452                         break;
 453                 }
 454                 return MOD_RES_PASSTHRU;
 455         }
 456
 457         void OnWebIRCAuth(LocalUser* user, const WebIRC::FlagMap* flags) CXX11_OVERRIDE
 458         {
 459                 // We are only interested in connection flags. If none have been
 460                 // given then we have nothing to do.
 461                 if (!flags)
 462                         return;
 463
 464                 WebIRC::FlagMap::const_iterator cport = flags->find("remote-port");
 465                 if (cport != flags->end())
 466                 {
 467                         // If we can't parse the port then just give up.
 468                         uint16_t port = ConvToNum<uint16_t>(cport->second);
 469                         if (port)
 470                         {
 471                                 switch (user->client_sa.family())
 472                                 {
 473                                         case AF_INET:
 474                                                 user->client_sa.in4.sin_port = htons(port);
 475                                                 break;
 476
 477                                         case AF_INET6:
 478                                                 user->client_sa.in6.sin6_port = htons(port);
 479                                                 break;
 480
 481                                         default:
 482                                                 // If we have reached this point then we have encountered a bug.
 483                                                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "BUG: OnWebIRCAuth(%s): socket type %d is unknown!",
 484                                                         user->uuid.c_str(), user->client_sa.family());
 485                                                 return;
 486                                 }
 487                         }
 488                 }
 489
 490                 WebIRC::FlagMap::const_iterator sport = flags->find("local-port");
 491                 if (sport != flags->end())
 492                 {
 493                         // If we can't parse the port then just give up.
 494                         uint16_t port = ConvToNum<uint16_t>(sport->second);
 495                         if (port)
 496                         {
 497                                 switch (user->server_sa.family())
 498                                 {
 499                                         case AF_INET:
 500                                                 user->server_sa.in4.sin_port = htons(port);
 501                                                 break;
 502
 503                                         case AF_INET6:
 504                                                 user->server_sa.in6.sin6_port = htons(port);
 505                                                 break;
 506
 507                                         default:
 508                                                 // If we have reached this point then we have encountered a bug.
 509                                                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "BUG: OnWebIRCAuth(%s): socket type %d is unknown!",
 510                                                         user->uuid.c_str(), user->server_sa.family());
 511                                                 return;
 512                                 }
 513                         }
 514                 }
 515         }
 516
 517         void OnWhois(Whois::Context& whois) CXX11_OVERRIDE
 518         {
 519                 if (!whois.IsSelfWhois() && !whois.GetSource()->HasPrivPermission("users/auspex"))
 520                         return;
 521
 522                 // If these fields are not set then the client is not using a gateway.
 523                 const std::string* realhost = cmdwebirc.realhost.get(whois.GetTarget());
 524                 const std::string* realip = cmdwebirc.realip.get(whois.GetTarget());
 525                 if (!realhost || !realip)
 526                         return;
 527
 528                 const std::string* gateway = cmdwebirc.gateway.get(whois.GetTarget());
 529                 if (gateway)
 530                         whois.SendLine(RPL_WHOISGATEWAY, *realhost, *realip, "is connected via the " + *gateway + " WebIRC gateway");
 531                 else
 532                         whois.SendLine(RPL_WHOISGATEWAY, *realhost, *realip, "is connected via an ident gateway");
 533         }
 534
 535         Version GetVersion() CXX11_OVERRIDE
 536         {
 537                 return Version("Adds the ability for IRC gateways to forward the real IP address of users connecting through them.", VF_VENDOR);
 538         }
 539 };
 540
 541 MODULE_INIT(ModuleCgiIRC)