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