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
 100         CmdResult HandleLocal(const std::vector<std::string>& parameters, LocalUser* user) CXX11_OVERRIDE
 101         {
 102                 if (user->registered == REG_ALL)
 103                         return CMD_FAILURE;
 104
 105                 irc::sockets::sockaddrs ipaddr;
 106                 if (!irc::sockets::aptosa(parameters[3], 0, ipaddr))
 107                 {
 108                         user->CommandFloodPenalty += 5000;
 109                         ServerInstance->SNO->WriteGlobalSno('a', "Connecting user %s tried to use WEBIRC but gave an invalid IP address.", user->GetFullRealHost().c_str());
 110                         return CMD_FAILURE;
 111                 }
 112
 113                 // If the hostname is malformed then we use the IP address instead.
 114                 bool host_ok = (parameters[2].length() <= ServerInstance->Config->Limits.MaxHost) && (parameters[2].find_first_not_of("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-") == std::string::npos);
 115                 const std::string& newhost = (host_ok ? parameters[2] : parameters[3]);
 116
 117                 for (std::vector<WebIRCHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 118                 {
 119                         // If we don't match the host then skip to the next host.
 120                         if (!iter->Matches(user, parameters[0]))
 121                                 continue;
 122
 123                         // The user matched a WebIRC block!
 124                         gateway.set(user, parameters[1]);
 125                         realhost.set(user, user->host);
 126                         realip.set(user, user->GetIPString());
 127
 128                         if (notify)
 129                                 ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s is using a WebIRC gateway; changing their IP/host from %s/%s to %s/%s.",
 130                                         user->nick.c_str(), user->GetIPString().c_str(), user->host.c_str(), parameters[3].c_str(), newhost.c_str());
 131
 132                         // Set the IP address and hostname sent via WEBIRC.
 133                         ChangeIP(user, parameters[3]);
 134                         user->host = user->dhost = newhost;
 135                         user->InvalidateCache();
 136                         return CMD_SUCCESS;
 137                 }
 138
 139                 user->CommandFloodPenalty += 5000;
 140                 ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s tried to use WEBIRC but didn't match any configured WebIRC hosts.", user->GetFullRealHost().c_str());
 141                 return CMD_FAILURE;
 142         }
 143 };
 144
 145
 146 /** Resolver for CGI:IRC hostnames encoded in ident/GECOS
 147  */
 148 class CGIResolver : public DNS::Request
 149 {
 150         std::string theiruid;
 151         LocalIntExt& waiting;
 152         bool notify;
 153  public:
 154         CGIResolver(DNS::Manager* mgr, Module* me, bool NotifyOpers, const std::string &source, LocalUser* u, LocalIntExt& ext)
 155                 : DNS::Request(mgr, me, source, DNS::QUERY_PTR)
 156                 , theiruid(u->uuid)
 157                 , waiting(ext)
 158                 , notify(NotifyOpers)
 159         {
 160         }
 161
 162         void OnLookupComplete(const DNS::Query *r) CXX11_OVERRIDE
 163         {
 164                 /* Check the user still exists */
 165                 User* them = ServerInstance->FindUUID(theiruid);
 166                 if ((them) && (!them->quitting))
 167                 {
 168                         LocalUser* lu = IS_LOCAL(them);
 169                         if (!lu)
 170                                 return;
 171
 172                         const DNS::ResourceRecord &ans_record = r->answers[0];
 173                         if (ans_record.rdata.empty() || ans_record.rdata.length() > ServerInstance->Config->Limits.MaxHost)
 174                                 return;
 175
 176                         if (notify)
 177                                 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());
 178
 179                         them->host = them->dhost = ans_record.rdata;
 180                         them->InvalidateCache();
 181                         lu->CheckLines(true);
 182                 }
 183         }
 184
 185         void OnError(const DNS::Query *r) CXX11_OVERRIDE
 186         {
 187                 if (!notify)
 188                         return;
 189
 190                 User* them = ServerInstance->FindUUID(theiruid);
 191                 if ((them) && (!them->quitting))
 192                 {
 193                         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());
 194                 }
 195         }
 196
 197         ~CGIResolver()
 198         {
 199                 User* them = ServerInstance->FindUUID(theiruid);
 200                 if (!them)
 201                         return;
 202                 int count = waiting.get(them);
 203                 if (count)
 204                         waiting.set(them, count - 1);
 205         }
 206 };
 207
 208 class ModuleCgiIRC : public Module
 209 {
 210         CommandWebIRC cmd;
 211         LocalIntExt waiting;
 212         dynamic_reference<DNS::Manager> DNS;
 213         std::vector<std::string> hosts;
 214
 215         static void RecheckClass(LocalUser* user)
 216         {
 217                 user->MyClass = NULL;
 218                 user->SetClass();
 219                 user->CheckClass();
 220         }
 221
 222         void HandleIdent(LocalUser* user, const std::string& newip)
 223         {
 224                 cmd.realhost.set(user, user->host);
 225                 cmd.realip.set(user, user->GetIPString());
 226                 ChangeIP(user, newip);
 227                 user->host = user->dhost = user->GetIPString();
 228                 user->InvalidateCache();
 229                 RecheckClass(user);
 230
 231                 // Don't create the resolver if the core couldn't put the user in a connect class or when dns is disabled
 232                 if (user->quitting || !DNS || !user->MyClass->resolvehostnames)
 233                         return;
 234
 235                 CGIResolver* r = new CGIResolver(*this->DNS, this, cmd.notify, newip, user, waiting);
 236                 try
 237                 {
 238                         waiting.set(user, waiting.get(user) + 1);
 239                         this->DNS->Process(r);
 240                 }
 241                 catch (DNS::Exception &ex)
 242                 {
 243                         int count = waiting.get(user);
 244                         if (count)
 245                                 waiting.set(user, count - 1);
 246                         delete r;
 247                         if (cmd.notify)
 248                                  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());
 249                 }
 250         }
 251
 252 public:
 253         ModuleCgiIRC()
 254                 : cmd(this)
 255                 , waiting("cgiirc-delay", ExtensionItem::EXT_USER, this)
 256                 , DNS(this, "DNS")
 257         {
 258         }
 259
 260         void init() CXX11_OVERRIDE
 261         {
 262                 ServerInstance->SNO->EnableSnomask('w', "CGIIRC");
 263         }
 264
 265         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 266         {
 267                 std::vector<std::string> identhosts;
 268                 std::vector<WebIRCHost> webirchosts;
 269
 270                 ConfigTagList tags = ServerInstance->Config->ConfTags("cgihost");
 271                 for (ConfigIter i = tags.first; i != tags.second; ++i)
 272                 {
 273                         ConfigTag* tag = i->second;
 274
 275                         // Ensure that we have the <cgihost:mask> parameter.
 276                         const std::string mask = tag->getString("mask");
 277                         if (mask.empty())
 278                                 throw ModuleException("<cgihost:mask> is a mandatory field, at " + tag->getTagLocation());
 279
 280                         // Determine what lookup type this host uses.
 281                         const std::string type = tag->getString("type");
 282                         if (stdalgo::string::equalsci(type, "ident"))
 283                         {
 284                                 // The IP address should be looked up from the hex IP address.
 285                                 identhosts.push_back(mask);
 286                         }
 287                         else if (stdalgo::string::equalsci(type, "webirc"))
 288                         {
 289                                 // The IP address will be received via the WEBIRC command.
 290                                 const std::string password = tag->getString("password");
 291
 292                                 // WebIRC blocks require a password.
 293                                 if (password.empty())
 294                                         throw ModuleException("When using <cgihost type=\"webirc\"> the password field is required, at " + tag->getTagLocation());
 295
 296                                 webirchosts.push_back(WebIRCHost(mask, password, tag->getString("hash")));
 297                         }
 298                         else
 299                         {
 300                                 throw ModuleException(type + " is an invalid <cgihost:mask> type, at " + tag->getTagLocation());
 301                         }
 302                 }
 303
 304                 // The host configuration was valid so we can apply it.
 305                 hosts.swap(identhosts);
 306                 cmd.hosts.swap(webirchosts);
 307
 308                 // Do we send an oper notice when a m_cgiirc client has their IP/host changed?
 309                 cmd.notify = ServerInstance->Config->ConfValue("cgiirc")->getBool("opernotice", true);
 310         }
 311
 312         ModResult OnCheckReady(LocalUser *user) CXX11_OVERRIDE
 313         {
 314                 if (waiting.get(user))
 315                         return MOD_RES_DENY;
 316
 317                 if (!cmd.realip.get(user))
 318                         return MOD_RES_PASSTHRU;
 319
 320                 RecheckClass(user);
 321                 if (user->quitting)
 322                         return MOD_RES_DENY;
 323
 324                 user->CheckLines(true);
 325                 if (user->quitting)
 326                         return MOD_RES_DENY;
 327
 328                 return MOD_RES_PASSTHRU;
 329         }
 330
 331         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE
 332         {
 333                 // If <connect:webirc> is not set then we have nothing to do.
 334                 const std::string webirc = myclass->config->getString("webirc");
 335                 if (webirc.empty())
 336                         return MOD_RES_PASSTHRU;
 337
 338                 // If the user is not connecting via a WebIRC gateway then they
 339                 // cannot match this connect class.
 340                 const std::string* gateway = cmd.gateway.get(user);
 341                 if (!gateway)
 342                         return MOD_RES_DENY;
 343
 344                 // If the gateway matches the <connect:webirc> constraint then
 345                 // allow the check to continue. Otherwise, reject it.
 346                 return InspIRCd::Match(*gateway, webirc) ? MOD_RES_PASSTHRU : MOD_RES_DENY;
 347         }
 348
 349         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
 350         {
 351                 for (std::vector<std::string>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 352                 {
 353                         if (!InspIRCd::Match(user->host, *iter, ascii_case_insensitive_map) && !InspIRCd::MatchCIDR(user->GetIPString(), *iter, ascii_case_insensitive_map))
 354                                 continue;
 355
 356                         CheckIdent(user); // Nothing on failure.
 357                         user->CheckLines(true);
 358                         break;
 359                 }
 360                 return MOD_RES_PASSTHRU;
 361         }
 362
 363         bool CheckIdent(LocalUser* user)
 364         {
 365                 const char* ident;
 366                 in_addr newip;
 367
 368                 if (user->ident.length() == 8)
 369                         ident = user->ident.c_str();
 370                 else if (user->ident.length() == 9 && user->ident[0] == '~')
 371                         ident = user->ident.c_str() + 1;
 372                 else
 373                         return false;
 374
 375                 errno = 0;
 376                 unsigned long ipaddr = strtoul(ident, NULL, 16);
 377                 if (errno)
 378                         return false;
 379                 newip.s_addr = htonl(ipaddr);
 380                 std::string newipstr(inet_ntoa(newip));
 381
 382                 user->ident = "~cgiirc";
 383                 HandleIdent(user, newipstr);
 384
 385                 return true;
 386         }
 387
 388         Version GetVersion() CXX11_OVERRIDE
 389         {
 390                 return Version("Change user's hosts connecting from known CGI:IRC hosts",VF_VENDOR);
 391         }
 392 };
 393
 394 MODULE_INIT(ModuleCgiIRC)