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