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 "xline.h"
  28 #include "modules/dns.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         const std::string hostmask;
  48         const std::string password;
  49         const std::string passhash;
  50
  51  public:
  52         WebIRCHost(const std::string& mask, const std::string& pass, const std::string& hash)
  53                 : hostmask(mask)
  54                 , password(pass)
  55                 , passhash(hash)
  56         {
  57         }
  58
  59         bool Matches(LocalUser* user, const std::string& pass) const
  60         {
  61                 // Did the user send a valid password?
  62                 if (!ServerInstance->PassCompare(user, password, pass, passhash))
  63                         return false;
  64
  65                 // Does the user's hostname match our hostmask?
  66                 if (InspIRCd::Match(user->host, hostmask, ascii_case_insensitive_map))
  67                         return true;
  68
  69                 // Does the user's IP address match our hostmask?
  70                 return InspIRCd::MatchCIDR(user->GetIPString(), hostmask, ascii_case_insensitive_map);
  71         }
  72 };
  73
  74 /*
  75  * WEBIRC
  76  *  This is used for the webirc method of CGIIRC auth, and is (really) the best way to do these things.
  77  *  Syntax: WEBIRC password gateway hostname ip
  78  *  Where password is a shared key, gateway is the name of the WebIRC gateway and version (e.g. cgiirc), hostname
  79  *  is the resolved host of the client issuing the command and IP is the real IP of the client.
  80  *
  81  * How it works:
  82  *  To tie in with the rest of cgiirc module, and to avoid race conditions, /webirc is only processed locally
  83  *  and simply sets metadata on the user, which is later decoded on full connect to give something meaningful.
  84  */
  85 class CommandWebIRC : public SplitCommand
  86 {
  87  public:
  88         std::vector<WebIRCHost> hosts;
  89         bool notify;
  90         StringExtItem gateway;
  91         StringExtItem realhost;
  92         StringExtItem realip;
  93
  94         CommandWebIRC(Module* Creator)
  95                 : SplitCommand(Creator, "WEBIRC", 4)
  96                 , gateway("cgiirc_gateway", ExtensionItem::EXT_USER, Creator)
  97                 , realhost("cgiirc_realhost", ExtensionItem::EXT_USER, Creator)
  98                 , realip("cgiirc_realip", ExtensionItem::EXT_USER, Creator)
  99         {
 100                 allow_empty_last_param = false;
 101                 works_before_reg = true;
 102                 this->syntax = "password gateway hostname ip";
 103         }
 104
 105         CmdResult HandleLocal(const std::vector<std::string>& parameters, LocalUser* user) CXX11_OVERRIDE
 106         {
 107                 if (user->registered == REG_ALL)
 108                         return CMD_FAILURE;
 109
 110                 irc::sockets::sockaddrs ipaddr;
 111                 if (!irc::sockets::aptosa(parameters[3], 0, ipaddr))
 112                 {
 113                         user->CommandFloodPenalty += 5000;
 114                         ServerInstance->SNO->WriteGlobalSno('a', "Connecting user %s tried to use WEBIRC but gave an invalid IP address.", user->GetFullRealHost().c_str());
 115                         return CMD_FAILURE;
 116                 }
 117
 118                 // If the hostname is malformed then we use the IP address instead.
 119                 bool host_ok = (parameters[2].length() <= ServerInstance->Config->Limits.MaxHost) && (parameters[2].find_first_not_of("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-") == std::string::npos);
 120                 const std::string& newhost = (host_ok ? parameters[2] : parameters[3]);
 121
 122                 for (std::vector<WebIRCHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 123                 {
 124                         // If we don't match the host then skip to the next host.
 125                         if (!iter->Matches(user, parameters[0]))
 126                                 continue;
 127
 128                         // The user matched a WebIRC block!
 129                         gateway.set(user, parameters[1]);
 130                         realhost.set(user, user->host);
 131                         realip.set(user, user->GetIPString());
 132
 133                         if (notify)
 134                                 ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s is using a WebIRC gateway; changing their IP/host from %s/%s to %s/%s.",
 135                                         user->nick.c_str(), user->GetIPString().c_str(), user->host.c_str(), parameters[3].c_str(), newhost.c_str());
 136
 137                         // Set the IP address and hostname sent via WEBIRC.
 138                         ChangeIP(user, parameters[3]);
 139                         user->host = user->dhost = newhost;
 140                         user->InvalidateCache();
 141                         return CMD_SUCCESS;
 142                 }
 143
 144                 user->CommandFloodPenalty += 5000;
 145                 ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s tried to use WEBIRC but didn't match any configured WebIRC hosts.", user->GetFullRealHost().c_str());
 146                 return CMD_FAILURE;
 147         }
 148 };
 149
 150
 151 /** Resolver for CGI:IRC hostnames encoded in ident/GECOS
 152  */
 153 class CGIResolver : public DNS::Request
 154 {
 155         std::string theiruid;
 156         LocalIntExt& waiting;
 157         bool notify;
 158  public:
 159         CGIResolver(DNS::Manager* mgr, Module* me, bool NotifyOpers, const std::string &source, LocalUser* u, LocalIntExt& ext)
 160                 : DNS::Request(mgr, me, source, DNS::QUERY_PTR)
 161                 , theiruid(u->uuid)
 162                 , waiting(ext)
 163                 , notify(NotifyOpers)
 164         {
 165         }
 166
 167         void OnLookupComplete(const DNS::Query *r) CXX11_OVERRIDE
 168         {
 169                 /* Check the user still exists */
 170                 User* them = ServerInstance->FindUUID(theiruid);
 171                 if ((them) && (!them->quitting))
 172                 {
 173                         LocalUser* lu = IS_LOCAL(them);
 174                         if (!lu)
 175                                 return;
 176
 177                         const DNS::ResourceRecord &ans_record = r->answers[0];
 178                         if (ans_record.rdata.empty() || ans_record.rdata.length() > ServerInstance->Config->Limits.MaxHost)
 179                                 return;
 180
 181                         if (notify)
 182                                 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());
 183
 184                         them->host = them->dhost = ans_record.rdata;
 185                         them->InvalidateCache();
 186                         lu->CheckLines(true);
 187                 }
 188         }
 189
 190         void OnError(const DNS::Query *r) CXX11_OVERRIDE
 191         {
 192                 if (!notify)
 193                         return;
 194
 195                 User* them = ServerInstance->FindUUID(theiruid);
 196                 if ((them) && (!them->quitting))
 197                 {
 198                         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());
 199                 }
 200         }
 201
 202         ~CGIResolver()
 203         {
 204                 User* them = ServerInstance->FindUUID(theiruid);
 205                 if (!them)
 206                         return;
 207                 int count = waiting.get(them);
 208                 if (count)
 209                         waiting.set(them, count - 1);
 210         }
 211 };
 212
 213 class ModuleCgiIRC : public Module, public Whois::EventListener
 214 {
 215         CommandWebIRC cmd;
 216         LocalIntExt waiting;
 217         dynamic_reference<DNS::Manager> DNS;
 218         std::vector<std::string> hosts;
 219
 220         static void RecheckClass(LocalUser* user)
 221         {
 222                 user->MyClass = NULL;
 223                 user->SetClass();
 224                 user->CheckClass();
 225         }
 226
 227         void HandleIdent(LocalUser* user, const std::string& newip)
 228         {
 229                 cmd.realhost.set(user, user->host);
 230                 cmd.realip.set(user, user->GetIPString());
 231                 ChangeIP(user, newip);
 232                 user->host = user->dhost = user->GetIPString();
 233                 user->InvalidateCache();
 234                 RecheckClass(user);
 235
 236                 // Don't create the resolver if the core couldn't put the user in a connect class or when dns is disabled
 237                 if (user->quitting || !DNS || !user->MyClass->resolvehostnames)
 238                         return;
 239
 240                 CGIResolver* r = new CGIResolver(*this->DNS, this, cmd.notify, newip, user, waiting);
 241                 try
 242                 {
 243                         waiting.set(user, waiting.get(user) + 1);
 244                         this->DNS->Process(r);
 245                 }
 246                 catch (DNS::Exception &ex)
 247                 {
 248                         int count = waiting.get(user);
 249                         if (count)
 250                                 waiting.set(user, count - 1);
 251                         delete r;
 252                         if (cmd.notify)
 253                                  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());
 254                 }
 255         }
 256
 257 public:
 258         ModuleCgiIRC()
 259                 : Whois::EventListener(this)
 260                 , cmd(this)
 261                 , waiting("cgiirc-delay", ExtensionItem::EXT_USER, this)
 262                 , DNS(this, "DNS")
 263         {
 264         }
 265
 266         void init() CXX11_OVERRIDE
 267         {
 268                 ServerInstance->SNO->EnableSnomask('w', "CGIIRC");
 269         }
 270
 271         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 272         {
 273                 std::vector<std::string> identhosts;
 274                 std::vector<WebIRCHost> webirchosts;
 275
 276                 ConfigTagList tags = ServerInstance->Config->ConfTags("cgihost");
 277                 for (ConfigIter i = tags.first; i != tags.second; ++i)
 278                 {
 279                         ConfigTag* tag = i->second;
 280
 281                         // Ensure that we have the <cgihost:mask> parameter.
 282                         const std::string mask = tag->getString("mask");
 283                         if (mask.empty())
 284                                 throw ModuleException("<cgihost:mask> is a mandatory field, at " + tag->getTagLocation());
 285
 286                         // Determine what lookup type this host uses.
 287                         const std::string type = tag->getString("type");
 288                         if (stdalgo::string::equalsci(type, "ident"))
 289                         {
 290                                 // The IP address should be looked up from the hex IP address.
 291                                 identhosts.push_back(mask);
 292                         }
 293                         else if (stdalgo::string::equalsci(type, "webirc"))
 294                         {
 295                                 // The IP address will be received via the WEBIRC command.
 296                                 const std::string password = tag->getString("password");
 297
 298                                 // WebIRC blocks require a password.
 299                                 if (password.empty())
 300                                         throw ModuleException("When using <cgihost type=\"webirc\"> the password field is required, at " + tag->getTagLocation());
 301
 302                                 webirchosts.push_back(WebIRCHost(mask, password, tag->getString("hash")));
 303                         }
 304                         else
 305                         {
 306                                 throw ModuleException(type + " is an invalid <cgihost:mask> type, at " + tag->getTagLocation());
 307                         }
 308                 }
 309
 310                 // The host configuration was valid so we can apply it.
 311                 hosts.swap(identhosts);
 312                 cmd.hosts.swap(webirchosts);
 313
 314                 // Do we send an oper notice when a m_cgiirc client has their IP/host changed?
 315                 cmd.notify = ServerInstance->Config->ConfValue("cgiirc")->getBool("opernotice", true);
 316         }
 317
 318         ModResult OnCheckReady(LocalUser *user) CXX11_OVERRIDE
 319         {
 320                 if (waiting.get(user))
 321                         return MOD_RES_DENY;
 322
 323                 if (!cmd.realip.get(user))
 324                         return MOD_RES_PASSTHRU;
 325
 326                 RecheckClass(user);
 327                 if (user->quitting)
 328                         return MOD_RES_DENY;
 329
 330                 user->CheckLines(true);
 331                 if (user->quitting)
 332                         return MOD_RES_DENY;
 333
 334                 return MOD_RES_PASSTHRU;
 335         }
 336
 337         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE
 338         {
 339                 // If <connect:webirc> is not set then we have nothing to do.
 340                 const std::string webirc = myclass->config->getString("webirc");
 341                 if (webirc.empty())
 342                         return MOD_RES_PASSTHRU;
 343
 344                 // If the user is not connecting via a WebIRC gateway then they
 345                 // cannot match this connect class.
 346                 const std::string* gateway = cmd.gateway.get(user);
 347                 if (!gateway)
 348                         return MOD_RES_DENY;
 349
 350                 // If the gateway matches the <connect:webirc> constraint then
 351                 // allow the check to continue. Otherwise, reject it.
 352                 return InspIRCd::Match(*gateway, webirc) ? MOD_RES_PASSTHRU : MOD_RES_DENY;
 353         }
 354
 355         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
 356         {
 357                 for (std::vector<std::string>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 358                 {
 359                         if (!InspIRCd::Match(user->host, *iter, ascii_case_insensitive_map) && !InspIRCd::MatchCIDR(user->GetIPString(), *iter, ascii_case_insensitive_map))
 360                                 continue;
 361
 362                         CheckIdent(user); // Nothing on failure.
 363                         user->CheckLines(true);
 364                         break;
 365                 }
 366                 return MOD_RES_PASSTHRU;
 367         }
 368
 369         void OnWhois(Whois::Context& whois) CXX11_OVERRIDE
 370         {
 371                 if (!whois.IsSelfWhois() && !whois.GetSource()->HasPrivPermission("users/auspex"))
 372                         return;
 373
 374                 // If these fields are not set then the client is not using a gateway.
 375                 const std::string* realhost = cmd.realhost.get(whois.GetTarget());
 376                 const std::string* realip = cmd.realip.get(whois.GetTarget());
 377                 if (!realhost || !realip)
 378                         return;
 379
 380                 const std::string* gateway = cmd.gateway.get(whois.GetTarget());
 381                 if (gateway)
 382                         whois.SendLine(RPL_WHOISGATEWAY, *realhost, *realip, "is connected via the " + *gateway + " WebIRC gateway");
 383                 else
 384                         whois.SendLine(RPL_WHOISGATEWAY, *realhost, *realip, "is connected via an ident gateway");
 385         }
 386
 387         bool CheckIdent(LocalUser* user)
 388         {
 389                 const char* ident;
 390                 in_addr newip;
 391
 392                 if (user->ident.length() == 8)
 393                         ident = user->ident.c_str();
 394                 else if (user->ident.length() == 9 && user->ident[0] == '~')
 395                         ident = user->ident.c_str() + 1;
 396                 else
 397                         return false;
 398
 399                 errno = 0;
 400                 unsigned long ipaddr = strtoul(ident, NULL, 16);
 401                 if (errno)
 402                         return false;
 403                 newip.s_addr = htonl(ipaddr);
 404                 std::string newipstr(inet_ntoa(newip));
 405
 406                 user->ident = "~cgiirc";
 407                 HandleIdent(user, newipstr);
 408
 409                 return true;
 410         }
 411
 412         Version GetVersion() CXX11_OVERRIDE
 413         {
 414                 return Version("Change user's hosts connecting from known CGI:IRC hosts",VF_VENDOR);
 415         }
 416 };
 417
 418 MODULE_INIT(ModuleCgiIRC)