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 // We need this method up here so that it can be accessed from anywhere
  31 static void ChangeIP(User* user, const std::string& newip)
  32 {
  33         ServerInstance->Users->RemoveCloneCounts(user);
  34         user->SetClientIP(newip.c_str());
  35         ServerInstance->Users->AddClone(user);
  36 }
  37
  38 // Encapsulates information about a WebIRC host.
  39 class WebIRCHost
  40 {
  41  private:
  42         const std::string hostmask;
  43         const std::string password;
  44         const std::string passhash;
  45
  46  public:
  47         WebIRCHost(const std::string& mask, const std::string& pass, const std::string& hash)
  48                 : hostmask(mask)
  49                 , password(pass)
  50                 , passhash(hash)
  51         {
  52         }
  53
  54         bool Matches(LocalUser* user, const std::string& pass) const
  55         {
  56                 // Did the user send a valid password?
  57                 if (!ServerInstance->PassCompare(user, password, pass, passhash))
  58                         return false;
  59
  60                 // Does the user's hostname match our hostmask?
  61                 if (InspIRCd::Match(user->host, hostmask, ascii_case_insensitive_map))
  62                         return true;
  63
  64                 // Does the user's IP address match our hostmask?
  65                 return InspIRCd::MatchCIDR(user->GetIPString(), hostmask, ascii_case_insensitive_map);
  66         }
  67 };
  68
  69 /*
  70  * WEBIRC
  71  *  This is used for the webirc method of CGIIRC auth, and is (really) the best way to do these things.
  72  *  Syntax: WEBIRC password gateway hostname ip
  73  *  Where password is a shared key, gateway is the name of the WebIRC gateway and version (e.g. cgiirc), hostname
  74  *  is the resolved host of the client issuing the command and IP is the real IP of the client.
  75  *
  76  * How it works:
  77  *  To tie in with the rest of cgiirc module, and to avoid race conditions, /webirc is only processed locally
  78  *  and simply sets metadata on the user, which is later decoded on full connect to give something meaningful.
  79  */
  80 class CommandWebIRC : public SplitCommand
  81 {
  82  public:
  83         std::vector<WebIRCHost> hosts;
  84         bool notify;
  85         StringExtItem gateway;
  86         StringExtItem realhost;
  87         StringExtItem realip;
  88
  89         CommandWebIRC(Module* Creator)
  90                 : SplitCommand(Creator, "WEBIRC", 4)
  91                 , gateway("cgiirc_gateway", ExtensionItem::EXT_USER, Creator)
  92                 , realhost("cgiirc_realhost", ExtensionItem::EXT_USER, Creator)
  93                 , realip("cgiirc_realip", ExtensionItem::EXT_USER, Creator)
  94                 {
  95                         allow_empty_last_param = false;
  96                         works_before_reg = true;
  97                         this->syntax = "password gateway hostname ip";
  98                 }
  99                 CmdResult HandleLocal(const std::vector<std::string>& parameters, LocalUser* user)
 100                 {
 101                         if(user->registered == REG_ALL)
 102                                 return CMD_FAILURE;
 103
 104                         irc::sockets::sockaddrs ipaddr;
 105                         if (!irc::sockets::aptosa(parameters[3], 0, ipaddr))
 106                         {
 107                                 user->CommandFloodPenalty += 5000;
 108                                 ServerInstance->SNO->WriteGlobalSno('a', "Connecting user %s tried to use WEBIRC but gave an invalid IP address.", user->GetFullRealHost().c_str());
 109                                 return CMD_FAILURE;
 110                         }
 111
 112                         for (std::vector<WebIRCHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 113                         {
 114                                 // If we don't match the host then skip to the next host.
 115                                 if (!iter->Matches(user, parameters[0]))
 116                                         continue;
 117
 118                                 {
 119                                         {
 120                                                 gateway.set(user, parameters[1]);
 121                                                 realhost.set(user, user->host);
 122                                                 realip.set(user, user->GetIPString());
 123
 124                                                 // Check if we're happy with the provided hostname. If it's problematic then make sure we won't set a host later, just the IP
 125                                                 bool host_ok = (parameters[2].length() <= ServerInstance->Config->Limits.MaxHost) && (parameters[2].find_first_not_of("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-") == std::string::npos);
 126                                                 const std::string& newhost = (host_ok ? parameters[2] : parameters[3]);
 127
 128                                                 if (notify)
 129                                                         ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s detected as using CGI:IRC (%s), changing real host to %s from %s", user->nick.c_str(), user->host.c_str(), newhost.c_str(), user->host.c_str());
 130
 131                                                 // Where the magic happens - change their IP
 132                                                 ChangeIP(user, parameters[3]);
 133                                                 // And follow this up by changing their host
 134                                                 user->host = user->dhost = newhost;
 135                                                 user->InvalidateCache();
 136
 137                                                 return CMD_SUCCESS;
 138                                         }
 139                                 }
 140                         }
 141
 142                         user->CommandFloodPenalty += 5000;
 143                         ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s tried to use WEBIRC, but didn't match any configured webirc blocks.", user->GetFullRealHost().c_str());
 144                         return CMD_FAILURE;
 145                 }
 146 };
 147
 148
 149 /** Resolver for CGI:IRC hostnames encoded in ident/GECOS
 150  */
 151 class CGIResolver : public DNS::Request
 152 {
 153         std::string theiruid;
 154         LocalIntExt& waiting;
 155         bool notify;
 156  public:
 157         CGIResolver(DNS::Manager* mgr, Module* me, bool NotifyOpers, const std::string &source, LocalUser* u, LocalIntExt& ext)
 158                 : DNS::Request(mgr, me, source, DNS::QUERY_PTR)
 159                 , theiruid(u->uuid)
 160                 , waiting(ext)
 161                 , notify(NotifyOpers)
 162         {
 163         }
 164
 165         void OnLookupComplete(const DNS::Query *r) CXX11_OVERRIDE
 166         {
 167                 /* Check the user still exists */
 168                 User* them = ServerInstance->FindUUID(theiruid);
 169                 if ((them) && (!them->quitting))
 170                 {
 171                         LocalUser* lu = IS_LOCAL(them);
 172                         if (!lu)
 173                                 return;
 174
 175                         const DNS::ResourceRecord &ans_record = r->answers[0];
 176                         if (ans_record.rdata.empty() || ans_record.rdata.length() > ServerInstance->Config->Limits.MaxHost)
 177                                 return;
 178
 179                         if (notify)
 180                                 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());
 181
 182                         them->host = them->dhost = ans_record.rdata;
 183                         them->InvalidateCache();
 184                         lu->CheckLines(true);
 185                 }
 186         }
 187
 188         void OnError(const DNS::Query *r) CXX11_OVERRIDE
 189         {
 190                 if (!notify)
 191                         return;
 192
 193                 User* them = ServerInstance->FindUUID(theiruid);
 194                 if ((them) && (!them->quitting))
 195                 {
 196                         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());
 197                 }
 198         }
 199
 200         ~CGIResolver()
 201         {
 202                 User* them = ServerInstance->FindUUID(theiruid);
 203                 if (!them)
 204                         return;
 205                 int count = waiting.get(them);
 206                 if (count)
 207                         waiting.set(them, count - 1);
 208         }
 209 };
 210
 211 class ModuleCgiIRC : public Module
 212 {
 213         CommandWebIRC cmd;
 214         LocalIntExt waiting;
 215         dynamic_reference<DNS::Manager> DNS;
 216         std::vector<std::string> hosts;
 217
 218         static void RecheckClass(LocalUser* user)
 219         {
 220                 user->MyClass = NULL;
 221                 user->SetClass();
 222                 user->CheckClass();
 223         }
 224
 225         void HandleIdent(LocalUser* user, const std::string& newip)
 226         {
 227                 cmd.realhost.set(user, user->host);
 228                 cmd.realip.set(user, user->GetIPString());
 229                 ChangeIP(user, newip);
 230                 user->host = user->dhost = user->GetIPString();
 231                 user->InvalidateCache();
 232                 RecheckClass(user);
 233
 234                 // Don't create the resolver if the core couldn't put the user in a connect class or when dns is disabled
 235                 if (user->quitting || !DNS || !user->MyClass->resolvehostnames)
 236                         return;
 237
 238                 CGIResolver* r = new CGIResolver(*this->DNS, this, cmd.notify, newip, user, waiting);
 239                 try
 240                 {
 241                         waiting.set(user, waiting.get(user) + 1);
 242                         this->DNS->Process(r);
 243                 }
 244                 catch (DNS::Exception &ex)
 245                 {
 246                         int count = waiting.get(user);
 247                         if (count)
 248                                 waiting.set(user, count - 1);
 249                         delete r;
 250                         if (cmd.notify)
 251                                  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());
 252                 }
 253         }
 254
 255 public:
 256         ModuleCgiIRC()
 257                 : cmd(this)
 258                 , waiting("cgiirc-delay", ExtensionItem::EXT_USER, this)
 259                 , DNS(this, "DNS")
 260         {
 261         }
 262
 263         void init() CXX11_OVERRIDE
 264         {
 265                 ServerInstance->SNO->EnableSnomask('w', "CGIIRC");
 266         }
 267
 268         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 269         {
 270                 std::vector<std::string> identhosts;
 271                 std::vector<WebIRCHost> webirchosts;
 272
 273                 ConfigTagList tags = ServerInstance->Config->ConfTags("cgihost");
 274                 for (ConfigIter i = tags.first; i != tags.second; ++i)
 275                 {
 276                         ConfigTag* tag = i->second;
 277
 278                         // Ensure that we have the <cgihost:mask> parameter.
 279                         const std::string mask = tag->getString("mask");
 280                         if (mask.empty())
 281                                 throw ModuleException("<cgihost:mask> is a mandatory field, at " + tag->getTagLocation());
 282
 283                         // Determine what lookup type this host uses.
 284                         const std::string type = tag->getString("type");
 285                         if (stdalgo::string::equalsci(type, "ident"))
 286                         {
 287                                 // The IP address should be looked up from the hex IP address.
 288                                 identhosts.push_back(mask);
 289                         }
 290                         else if (stdalgo::string::equalsci(type, "webirc"))
 291                         {
 292                                 // The IP address will be received via the WEBIRC command.
 293                                 const std::string password = tag->getString("password");
 294
 295                                 // WebIRC blocks require a password.
 296                                 if (password.empty())
 297                                         throw ModuleException("When using <cgihost type=\"webirc\"> the password field is required, at " + tag->getTagLocation());
 298
 299                                 webirchosts.push_back(WebIRCHost(mask, password, tag->getString("hash")));
 300                         }
 301                         else
 302                         {
 303                                 throw ModuleException(type + " is an invalid <cgihost:mask> type, at " + tag->getTagLocation());
 304                         }
 305                 }
 306
 307                 // The host configuration was valid so we can apply it.
 308                 hosts.swap(identhosts);
 309                 cmd.hosts.swap(webirchosts);
 310
 311                 // Do we send an oper notice when a m_cgiirc client has their IP/host changed?
 312                 cmd.notify = ServerInstance->Config->ConfValue("cgiirc")->getBool("opernotice", true);
 313         }
 314
 315         ModResult OnCheckReady(LocalUser *user) CXX11_OVERRIDE
 316         {
 317                 if (waiting.get(user))
 318                         return MOD_RES_DENY;
 319
 320                 if (!cmd.realip.get(user))
 321                         return MOD_RES_PASSTHRU;
 322
 323                 RecheckClass(user);
 324                 if (user->quitting)
 325                         return MOD_RES_DENY;
 326
 327                 user->CheckLines(true);
 328                 if (user->quitting)
 329                         return MOD_RES_DENY;
 330
 331                 return MOD_RES_PASSTHRU;
 332         }
 333
 334         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE
 335         {
 336                 // If <connect:webirc> is not set then we have nothing to do.
 337                 const std::string webirc = myclass->config->getString("webirc");
 338                 if (webirc.empty())
 339                         return MOD_RES_PASSTHRU;
 340
 341                 // If the user is not connecting via a WebIRC gateway then they
 342                 // cannot match this connect class.
 343                 const std::string* gateway = cmd.gateway.get(user);
 344                 if (!gateway)
 345                         return MOD_RES_DENY;
 346
 347                 // If the gateway matches the <connect:webirc> constraint then
 348                 // allow the check to continue. Otherwise, reject it.
 349                 return InspIRCd::Match(*gateway, webirc) ? MOD_RES_PASSTHRU : MOD_RES_DENY;
 350         }
 351
 352         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
 353         {
 354                 for (std::vector<std::string>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 355                 {
 356                         if (!InspIRCd::Match(user->host, *iter, ascii_case_insensitive_map) && !InspIRCd::MatchCIDR(user->GetIPString(), *iter, ascii_case_insensitive_map))
 357                                 continue;
 358
 359                         CheckIdent(user); // Nothing on failure.
 360                         user->CheckLines(true);
 361                         break;
 362                 }
 363                 return MOD_RES_PASSTHRU;
 364         }
 365
 366         bool CheckIdent(LocalUser* user)
 367         {
 368                 const char* ident;
 369                 in_addr newip;
 370
 371                 if (user->ident.length() == 8)
 372                         ident = user->ident.c_str();
 373                 else if (user->ident.length() == 9 && user->ident[0] == '~')
 374                         ident = user->ident.c_str() + 1;
 375                 else
 376                         return false;
 377
 378                 errno = 0;
 379                 unsigned long ipaddr = strtoul(ident, NULL, 16);
 380                 if (errno)
 381                         return false;
 382                 newip.s_addr = htonl(ipaddr);
 383                 std::string newipstr(inet_ntoa(newip));
 384
 385                 user->ident = "~cgiirc";
 386                 HandleIdent(user, newipstr);
 387
 388                 return true;
 389         }
 390
 391         Version GetVersion() CXX11_OVERRIDE
 392         {
 393                 return Version("Change user's hosts connecting from known CGI:IRC hosts",VF_VENDOR);
 394         }
 395 };
 396
 397 MODULE_INIT(ModuleCgiIRC)