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/dns.h"
  28 #include "modules/ssl.h"
  29
  30 enum
  31 {
  32         RPL_WHOISGATEWAY = 350
  33 };
  34
  35 // We need this method up here so that it can be accessed from anywhere
  36 static void ChangeIP(User* user, const std::string& newip)
  37 {
  38         ServerInstance->Users->RemoveCloneCounts(user);
  39         user->SetClientIP(newip.c_str());
  40         ServerInstance->Users->AddClone(user);
  41 }
  42
  43 // Encapsulates information about a WebIRC host.
  44 class WebIRCHost
  45 {
  46  private:
  47         std::string hostmask;
  48         std::string fingerprint;
  49         std::string password;
  50         std::string passhash;
  51
  52  public:
  53         WebIRCHost(const std::string& mask, const std::string& fp, const std::string& pass, const std::string& hash)
  54                 : hostmask(mask)
  55                 , fingerprint(fp)
  56                 , password(pass)
  57                 , passhash(hash)
  58         {
  59         }
  60
  61         bool Matches(LocalUser* user, const std::string& pass) const
  62         {
  63                 // Did the user send a valid password?
  64                 if (!password.empty() && !ServerInstance->PassCompare(user, password, pass, passhash))
  65                         return false;
  66
  67                 // Does the user have a valid fingerprint?
  68                 const std::string fp = SSLClientCert::GetFingerprint(&user->eh);
  69                 if (!fingerprint.empty() && fp != fingerprint)
  70                         return false;
  71
  72                 // Does the user's hostname match our hostmask?
  73                 if (InspIRCd::Match(user->host, hostmask, ascii_case_insensitive_map))
  74                         return true;
  75
  76                 // Does the user's IP address match our hostmask?
  77                 return InspIRCd::MatchCIDR(user->GetIPString(), hostmask, ascii_case_insensitive_map);
  78         }
  79 };
  80
  81 /*
  82  * WEBIRC
  83  *  This is used for the webirc method of CGIIRC auth, and is (really) the best way to do these things.
  84  *  Syntax: WEBIRC password gateway hostname ip
  85  *  Where password is a shared key, gateway is the name of the WebIRC gateway and version (e.g. cgiirc), hostname
  86  *  is the resolved host of the client issuing the command and IP is the real IP of the client.
  87  *
  88  * How it works:
  89  *  To tie in with the rest of cgiirc module, and to avoid race conditions, /webirc is only processed locally
  90  *  and simply sets metadata on the user, which is later decoded on full connect to give something meaningful.
  91  */
  92 class CommandWebIRC : public SplitCommand
  93 {
  94  public:
  95         std::vector<WebIRCHost> hosts;
  96         bool notify;
  97         StringExtItem gateway;
  98         StringExtItem realhost;
  99         StringExtItem realip;
 100
 101         CommandWebIRC(Module* Creator)
 102                 : SplitCommand(Creator, "WEBIRC", 4)
 103                 , gateway("cgiirc_gateway", ExtensionItem::EXT_USER, Creator)
 104                 , realhost("cgiirc_realhost", ExtensionItem::EXT_USER, Creator)
 105                 , realip("cgiirc_realip", ExtensionItem::EXT_USER, Creator)
 106         {
 107                 allow_empty_last_param = false;
 108                 works_before_reg = true;
 109                 this->syntax = "password gateway hostname ip";
 110         }
 111
 112         CmdResult HandleLocal(const std::vector<std::string>& parameters, LocalUser* user) CXX11_OVERRIDE
 113         {
 114                 if (user->registered == REG_ALL)
 115                         return CMD_FAILURE;
 116
 117                 irc::sockets::sockaddrs ipaddr;
 118                 if (!irc::sockets::aptosa(parameters[3], 0, ipaddr))
 119                 {
 120                         user->CommandFloodPenalty += 5000;
 121                         ServerInstance->SNO->WriteGlobalSno('a', "Connecting user %s tried to use WEBIRC but gave an invalid IP address.", user->GetFullRealHost().c_str());
 122                         return CMD_FAILURE;
 123                 }
 124
 125                 // If the hostname is malformed then we use the IP address instead.
 126                 bool host_ok = (parameters[2].length() <= ServerInstance->Config->Limits.MaxHost) && (parameters[2].find_first_not_of("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-") == std::string::npos);
 127                 const std::string& newhost = (host_ok ? parameters[2] : parameters[3]);
 128
 129                 for (std::vector<WebIRCHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 130                 {
 131                         // If we don't match the host then skip to the next host.
 132                         if (!iter->Matches(user, parameters[0]))
 133                                 continue;
 134
 135                         // The user matched a WebIRC block!
 136                         gateway.set(user, parameters[1]);
 137                         realhost.set(user, user->host);
 138                         realip.set(user, user->GetIPString());
 139
 140                         if (notify)
 141                                 ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s is using a WebIRC gateway; changing their IP/host from %s/%s to %s/%s.",
 142                                         user->nick.c_str(), user->GetIPString().c_str(), user->host.c_str(), parameters[3].c_str(), newhost.c_str());
 143
 144                         // Set the IP address and hostname sent via WEBIRC.
 145                         ChangeIP(user, parameters[3]);
 146                         user->host = user->dhost = newhost;
 147                         user->InvalidateCache();
 148                         return CMD_SUCCESS;
 149                 }
 150
 151                 user->CommandFloodPenalty += 5000;
 152                 ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s tried to use WEBIRC but didn't match any configured WebIRC hosts.", user->GetFullRealHost().c_str());
 153                 return CMD_FAILURE;
 154         }
 155 };
 156
 157
 158 /** Resolver for CGI:IRC hostnames encoded in ident/GECOS
 159  */
 160 class CGIResolver : public DNS::Request
 161 {
 162         std::string theiruid;
 163         LocalIntExt& waiting;
 164         bool notify;
 165  public:
 166         CGIResolver(DNS::Manager* mgr, Module* me, bool NotifyOpers, const std::string &source, LocalUser* u, LocalIntExt& ext)
 167                 : DNS::Request(mgr, me, source, DNS::QUERY_PTR)
 168                 , theiruid(u->uuid)
 169                 , waiting(ext)
 170                 , notify(NotifyOpers)
 171         {
 172         }
 173
 174         void OnLookupComplete(const DNS::Query *r) CXX11_OVERRIDE
 175         {
 176                 /* Check the user still exists */
 177                 User* them = ServerInstance->FindUUID(theiruid);
 178                 if ((them) && (!them->quitting))
 179                 {
 180                         LocalUser* lu = IS_LOCAL(them);
 181                         if (!lu)
 182                                 return;
 183
 184                         const DNS::ResourceRecord &ans_record = r->answers[0];
 185                         if (ans_record.rdata.empty() || ans_record.rdata.length() > ServerInstance->Config->Limits.MaxHost)
 186                                 return;
 187
 188                         if (notify)
 189                                 ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s detected as using CGI:IRC (%s), changing real host to %s", them->nick.c_str(), them->host.c_str(), ans_record.rdata.c_str());
 190
 191                         them->host = them->dhost = ans_record.rdata;
 192                         them->InvalidateCache();
 193                         lu->CheckLines(true);
 194                 }
 195         }
 196
 197         void OnError(const DNS::Query *r) CXX11_OVERRIDE
 198         {
 199                 if (!notify)
 200                         return;
 201
 202                 User* them = ServerInstance->FindUUID(theiruid);
 203                 if ((them) && (!them->quitting))
 204                 {
 205                         ServerInstance->SNO->WriteToSnoMask('w', "Connecting user %s detected as using CGI:IRC (%s), but their host can't be resolved!", them->nick.c_str(), them->host.c_str());
 206                 }
 207         }
 208
 209         ~CGIResolver()
 210         {
 211                 User* them = ServerInstance->FindUUID(theiruid);
 212                 if (!them)
 213                         return;
 214                 int count = waiting.get(them);
 215                 if (count)
 216                         waiting.set(them, count - 1);
 217         }
 218 };
 219
 220 class ModuleCgiIRC : public Module, public Whois::EventListener
 221 {
 222         CommandWebIRC cmd;
 223         LocalIntExt waiting;
 224         dynamic_reference<DNS::Manager> DNS;
 225         std::vector<std::string> hosts;
 226
 227         static void RecheckClass(LocalUser* user)
 228         {
 229                 user->MyClass = NULL;
 230                 user->SetClass();
 231                 user->CheckClass();
 232         }
 233
 234         void HandleIdent(LocalUser* user, const std::string& newip)
 235         {
 236                 cmd.realhost.set(user, user->host);
 237                 cmd.realip.set(user, user->GetIPString());
 238                 ChangeIP(user, newip);
 239                 user->host = user->dhost = user->GetIPString();
 240                 user->InvalidateCache();
 241                 RecheckClass(user);
 242
 243                 // Don't create the resolver if the core couldn't put the user in a connect class or when dns is disabled
 244                 if (user->quitting || !DNS || !user->MyClass->resolvehostnames)
 245                         return;
 246
 247                 CGIResolver* r = new CGIResolver(*this->DNS, this, cmd.notify, newip, user, waiting);
 248                 try
 249                 {
 250                         waiting.set(user, waiting.get(user) + 1);
 251                         this->DNS->Process(r);
 252                 }
 253                 catch (DNS::Exception &ex)
 254                 {
 255                         int count = waiting.get(user);
 256                         if (count)
 257                                 waiting.set(user, count - 1);
 258                         delete r;
 259                         if (cmd.notify)
 260                                  ServerInstance->SNO->WriteToSnoMask('w', "Connecting user %s detected as using CGI:IRC (%s), but I could not resolve their hostname; %s", user->nick.c_str(), user->host.c_str(), ex.GetReason().c_str());
 261                 }
 262         }
 263
 264 public:
 265         ModuleCgiIRC()
 266                 : Whois::EventListener(this)
 267                 , cmd(this)
 268                 , waiting("cgiirc-delay", ExtensionItem::EXT_USER, this)
 269                 , DNS(this, "DNS")
 270         {
 271         }
 272
 273         void init() CXX11_OVERRIDE
 274         {
 275                 ServerInstance->SNO->EnableSnomask('w', "CGIIRC");
 276         }
 277
 278         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 279         {
 280                 std::vector<std::string> identhosts;
 281                 std::vector<WebIRCHost> webirchosts;
 282
 283                 ConfigTagList tags = ServerInstance->Config->ConfTags("cgihost");
 284                 for (ConfigIter i = tags.first; i != tags.second; ++i)
 285                 {
 286                         ConfigTag* tag = i->second;
 287
 288                         // Ensure that we have the <cgihost:mask> parameter.
 289                         const std::string mask = tag->getString("mask");
 290                         if (mask.empty())
 291                                 throw ModuleException("<cgihost:mask> is a mandatory field, at " + tag->getTagLocation());
 292
 293                         // Determine what lookup type this host uses.
 294                         const std::string type = tag->getString("type");
 295                         if (stdalgo::string::equalsci(type, "ident"))
 296                         {
 297                                 // The IP address should be looked up from the hex IP address.
 298                                 identhosts.push_back(mask);
 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/host changed?
 323                 cmd.notify = ServerInstance->Config->ConfValue("cgiirc")->getBool("opernotice", true);
 324         }
 325
 326         ModResult OnCheckReady(LocalUser *user) CXX11_OVERRIDE
 327         {
 328                 if (waiting.get(user))
 329                         return MOD_RES_DENY;
 330
 331                 if (!cmd.realip.get(user))
 332                         return MOD_RES_PASSTHRU;
 333
 334                 RecheckClass(user);
 335                 if (user->quitting)
 336                         return MOD_RES_DENY;
 337
 338                 user->CheckLines(true);
 339                 if (user->quitting)
 340                         return MOD_RES_DENY;
 341
 342                 return MOD_RES_PASSTHRU;
 343         }
 344
 345         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE
 346         {
 347                 // If <connect:webirc> is not set then we have nothing to do.
 348                 const std::string webirc = myclass->config->getString("webirc");
 349                 if (webirc.empty())
 350                         return MOD_RES_PASSTHRU;
 351
 352                 // If the user is not connecting via a WebIRC gateway then they
 353                 // cannot match this connect class.
 354                 const std::string* gateway = cmd.gateway.get(user);
 355                 if (!gateway)
 356                         return MOD_RES_DENY;
 357
 358                 // If the gateway matches the <connect:webirc> constraint then
 359                 // allow the check to continue. Otherwise, reject it.
 360                 return InspIRCd::Match(*gateway, webirc) ? MOD_RES_PASSTHRU : MOD_RES_DENY;
 361         }
 362
 363         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
 364         {
 365                 for (std::vector<std::string>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 366                 {
 367                         if (!InspIRCd::Match(user->host, *iter, ascii_case_insensitive_map) && !InspIRCd::MatchCIDR(user->GetIPString(), *iter, ascii_case_insensitive_map))
 368                                 continue;
 369
 370                         CheckIdent(user); // Nothing on failure.
 371                         user->CheckLines(true);
 372                         break;
 373                 }
 374                 return MOD_RES_PASSTHRU;
 375         }
 376
 377         void OnWhois(Whois::Context& whois) CXX11_OVERRIDE
 378         {
 379                 if (!whois.IsSelfWhois() && !whois.GetSource()->HasPrivPermission("users/auspex"))
 380                         return;
 381
 382                 // If these fields are not set then the client is not using a gateway.
 383                 const std::string* realhost = cmd.realhost.get(whois.GetTarget());
 384                 const std::string* realip = cmd.realip.get(whois.GetTarget());
 385                 if (!realhost || !realip)
 386                         return;
 387
 388                 const std::string* gateway = cmd.gateway.get(whois.GetTarget());
 389                 if (gateway)
 390                         whois.SendLine(RPL_WHOISGATEWAY, *realhost, *realip, "is connected via the " + *gateway + " WebIRC gateway");
 391                 else
 392                         whois.SendLine(RPL_WHOISGATEWAY, *realhost, *realip, "is connected via an ident gateway");
 393         }
 394
 395         bool CheckIdent(LocalUser* user)
 396         {
 397                 const char* ident;
 398                 in_addr newip;
 399
 400                 if (user->ident.length() == 8)
 401                         ident = user->ident.c_str();
 402                 else if (user->ident.length() == 9 && user->ident[0] == '~')
 403                         ident = user->ident.c_str() + 1;
 404                 else
 405                         return false;
 406
 407                 errno = 0;
 408                 unsigned long ipaddr = strtoul(ident, NULL, 16);
 409                 if (errno)
 410                         return false;
 411                 newip.s_addr = htonl(ipaddr);
 412                 std::string newipstr(inet_ntoa(newip));
 413
 414                 user->ident = "~cgiirc";
 415                 HandleIdent(user, newipstr);
 416
 417                 return true;
 418         }
 419
 420         Version GetVersion() CXX11_OVERRIDE
 421         {
 422                 return Version("Enables forwarding the IP/host information from a gateway to the IRC server", VF_VENDOR);
 423         }
 424 };
 425
 426 MODULE_INIT(ModuleCgiIRC)