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 CGItype { PASS, IDENT, PASSFIRST, IDENTFIRST, WEBIRC };
  31
  32 // We need this method up here so that it can be accessed from anywhere
  33 static void ChangeIP(User* user, const std::string& newip)
  34 {
  35         ServerInstance->Users->RemoveCloneCounts(user);
  36         user->SetClientIP(newip.c_str());
  37         ServerInstance->Users->AddClone(user);
  38 }
  39
  40 /** Holds a CGI site's details
  41  */
  42 class CGIhost
  43 {
  44 public:
  45         std::string hostmask;
  46         CGItype type;
  47         std::string password;
  48
  49         CGIhost(const std::string &mask, CGItype t, const std::string &spassword)
  50         : hostmask(mask), type(t), password(spassword)
  51         {
  52         }
  53 };
  54 typedef std::vector<CGIhost> CGIHostlist;
  55
  56 /*
  57  * WEBIRC
  58  *  This is used for the webirc method of CGIIRC auth, and is (really) the best way to do these things.
  59  *  Syntax: WEBIRC password gateway hostname ip
  60  *  Where password is a shared key, gateway is the name of the WebIRC gateway and version (e.g. cgiirc), hostname
  61  *  is the resolved host of the client issuing the command and IP is the real IP of the client.
  62  *
  63  * How it works:
  64  *  To tie in with the rest of cgiirc module, and to avoid race conditions, /webirc is only processed locally
  65  *  and simply sets metadata on the user, which is later decoded on full connect to give something meaningful.
  66  */
  67 class CommandWebirc : public Command
  68 {
  69  public:
  70         bool notify;
  71         StringExtItem gateway;
  72         StringExtItem realhost;
  73         StringExtItem realip;
  74
  75         CGIHostlist Hosts;
  76         CommandWebirc(Module* Creator)
  77                 : Command(Creator, "WEBIRC", 4)
  78                 , gateway("cgiirc_gateway", ExtensionItem::EXT_USER, Creator)
  79                 , realhost("cgiirc_realhost", ExtensionItem::EXT_USER, Creator)
  80                 , realip("cgiirc_realip", ExtensionItem::EXT_USER, Creator)
  81                 {
  82                         works_before_reg = true;
  83                         this->syntax = "password gateway hostname ip";
  84                 }
  85                 CmdResult Handle(const std::vector<std::string> &parameters, User *user)
  86                 {
  87                         if(user->registered == REG_ALL)
  88                                 return CMD_FAILURE;
  89
  90                         for(CGIHostlist::iterator iter = Hosts.begin(); iter != Hosts.end(); iter++)
  91                         {
  92                                 if(InspIRCd::Match(user->host, iter->hostmask, ascii_case_insensitive_map) || InspIRCd::MatchCIDR(user->GetIPString(), iter->hostmask, ascii_case_insensitive_map))
  93                                 {
  94                                         if(iter->type == WEBIRC && parameters[0] == iter->password)
  95                                         {
  96                                                 gateway.set(user, parameters[1]);
  97                                                 realhost.set(user, user->host);
  98                                                 realip.set(user, user->GetIPString());
  99
 100                                                 // 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
 101                                                 bool host_ok = (parameters[2].length() <= ServerInstance->Config->Limits.MaxHost);
 102                                                 const std::string& newhost = (host_ok ? parameters[2] : parameters[3]);
 103
 104                                                 if (notify)
 105                                                         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());
 106
 107                                                 // Where the magic happens - change their IP
 108                                                 ChangeIP(user, parameters[3]);
 109                                                 // And follow this up by changing their host
 110                                                 user->host = user->dhost = newhost;
 111                                                 user->InvalidateCache();
 112
 113                                                 return CMD_SUCCESS;
 114                                         }
 115                                 }
 116                         }
 117
 118                         ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s tried to use WEBIRC, but didn't match any configured webirc blocks.", user->GetFullRealHost().c_str());
 119                         return CMD_FAILURE;
 120                 }
 121 };
 122
 123
 124 /** Resolver for CGI:IRC hostnames encoded in ident/GECOS
 125  */
 126 class CGIResolver : public DNS::Request
 127 {
 128         std::string typ;
 129         std::string theiruid;
 130         LocalIntExt& waiting;
 131         bool notify;
 132  public:
 133         CGIResolver(DNS::Manager *mgr, Module* me, bool NotifyOpers, const std::string &source, LocalUser* u,
 134                         const std::string &ttype, LocalIntExt& ext)
 135                 : DNS::Request(mgr, me, source, DNS::QUERY_PTR), typ(ttype), theiruid(u->uuid),
 136                 waiting(ext), notify(NotifyOpers)
 137         {
 138         }
 139
 140         void OnLookupComplete(const DNS::Query *r) CXX11_OVERRIDE
 141         {
 142                 /* Check the user still exists */
 143                 User* them = ServerInstance->FindUUID(theiruid);
 144                 if ((them) && (!them->quitting))
 145                 {
 146                         LocalUser* lu = IS_LOCAL(them);
 147                         if (!lu)
 148                                 return;
 149
 150                         const DNS::ResourceRecord &ans_record = r->answers[0];
 151                         if (ans_record.rdata.empty() || ans_record.rdata.length() > ServerInstance->Config->Limits.MaxHost)
 152                                 return;
 153
 154                         if (notify)
 155                                 ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s detected as using CGI:IRC (%s), changing real host to %s from %s", them->nick.c_str(), them->host.c_str(), ans_record.rdata.c_str(), typ.c_str());
 156
 157                         them->host = them->dhost = ans_record.rdata;
 158                         them->InvalidateCache();
 159                         lu->CheckLines(true);
 160                 }
 161         }
 162
 163         void OnError(const DNS::Query *r) CXX11_OVERRIDE
 164         {
 165                 if (!notify)
 166                         return;
 167
 168                 User* them = ServerInstance->FindUUID(theiruid);
 169                 if ((them) && (!them->quitting))
 170                 {
 171                         ServerInstance->SNO->WriteToSnoMask('w', "Connecting user %s detected as using CGI:IRC (%s), but their host can't be resolved from their %s!", them->nick.c_str(), them->host.c_str(), typ.c_str());
 172                 }
 173         }
 174
 175         ~CGIResolver()
 176         {
 177                 User* them = ServerInstance->FindUUID(theiruid);
 178                 if (!them)
 179                         return;
 180                 int count = waiting.get(them);
 181                 if (count)
 182                         waiting.set(them, count - 1);
 183         }
 184 };
 185
 186 class ModuleCgiIRC : public Module
 187 {
 188         CommandWebirc cmd;
 189         LocalIntExt waiting;
 190         dynamic_reference<DNS::Manager> DNS;
 191
 192         static void RecheckClass(LocalUser* user)
 193         {
 194                 user->MyClass = NULL;
 195                 user->SetClass();
 196                 user->CheckClass();
 197         }
 198
 199         void HandleIdentOrPass(LocalUser* user, const std::string& newip, bool was_pass)
 200         {
 201                 cmd.realhost.set(user, user->host);
 202                 cmd.realip.set(user, user->GetIPString());
 203                 ChangeIP(user, newip);
 204                 user->host = user->dhost = user->GetIPString();
 205                 user->InvalidateCache();
 206                 RecheckClass(user);
 207
 208                 // Don't create the resolver if the core couldn't put the user in a connect class or when dns is disabled
 209                 if (user->quitting || !DNS || !user->MyClass->resolvehostnames)
 210                         return;
 211
 212                 CGIResolver* r = new CGIResolver(*this->DNS, this, cmd.notify, newip, user, (was_pass ? "PASS" : "IDENT"), waiting);
 213                 try
 214                 {
 215                         waiting.set(user, waiting.get(user) + 1);
 216                         this->DNS->Process(r);
 217                 }
 218                 catch (DNS::Exception &ex)
 219                 {
 220                         int count = waiting.get(user);
 221                         if (count)
 222                                 waiting.set(user, count - 1);
 223                         delete r;
 224                         if (cmd.notify)
 225                                  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());
 226                 }
 227         }
 228
 229 public:
 230         ModuleCgiIRC()
 231                 : cmd(this)
 232                 , waiting("cgiirc-delay", ExtensionItem::EXT_USER, this)
 233                 , DNS(this, "DNS")
 234         {
 235         }
 236
 237         void init() CXX11_OVERRIDE
 238         {
 239                 ServerInstance->SNO->EnableSnomask('w', "CGIIRC");
 240         }
 241
 242         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 243         {
 244                 cmd.Hosts.clear();
 245
 246                 // Do we send an oper notice when a CGI:IRC has their host changed?
 247                 cmd.notify = ServerInstance->Config->ConfValue("cgiirc")->getBool("opernotice", true);
 248
 249                 ConfigTagList tags = ServerInstance->Config->ConfTags("cgihost");
 250                 for (ConfigIter i = tags.first; i != tags.second; ++i)
 251                 {
 252                         ConfigTag* tag = i->second;
 253                         std::string hostmask = tag->getString("mask"); // An allowed CGI:IRC host
 254                         std::string type = tag->getString("type"); // What type of user-munging we do on this host.
 255                         std::string password = tag->getString("password");
 256
 257                         if(hostmask.length())
 258                         {
 259                                 if (type == "webirc" && password.empty())
 260                                 {
 261                                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Missing password in config: %s", hostmask.c_str());
 262                                 }
 263                                 else
 264                                 {
 265                                         CGItype cgitype;
 266                                         if (type == "pass")
 267                                                 cgitype = PASS;
 268                                         else if (type == "ident")
 269                                                 cgitype = IDENT;
 270                                         else if (type == "passfirst")
 271                                                 cgitype = PASSFIRST;
 272                                         else if (type == "webirc")
 273                                                 cgitype = WEBIRC;
 274                                         else
 275                                         {
 276                                                 cgitype = PASS;
 277                                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Invalid <cgihost:type> value in config: %s, setting it to \"pass\"", type.c_str());
 278                                         }
 279
 280                                         cmd.Hosts.push_back(CGIhost(hostmask, cgitype, password));
 281                                 }
 282                         }
 283                         else
 284                         {
 285                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Invalid <cgihost:mask> value in config: %s", hostmask.c_str());
 286                                 continue;
 287                         }
 288                 }
 289         }
 290
 291         ModResult OnCheckReady(LocalUser *user) CXX11_OVERRIDE
 292         {
 293                 if (waiting.get(user))
 294                         return MOD_RES_DENY;
 295
 296                 if (!cmd.realip.get(user))
 297                         return MOD_RES_PASSTHRU;
 298
 299                 RecheckClass(user);
 300                 if (user->quitting)
 301                         return MOD_RES_DENY;
 302
 303                 user->CheckLines(true);
 304                 if (user->quitting)
 305                         return MOD_RES_DENY;
 306
 307                 return MOD_RES_PASSTHRU;
 308         }
 309
 310         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE
 311         {
 312                 // If <connect:webirc> is not set then we have nothing to do.
 313                 const std::string webirc = myclass->config->getString("webirc");
 314                 if (webirc.empty())
 315                         return MOD_RES_PASSTHRU;
 316
 317                 // If the user is not connecting via a WebIRC gateway then they
 318                 // cannot match this connect class.
 319                 const std::string* gateway = cmd.gateway.get(user);
 320                 if (!gateway)
 321                         return MOD_RES_DENY;
 322
 323                 // If the gateway matches the <connect:webirc> constraint then
 324                 // allow the check to continue. Otherwise, reject it.
 325                 return InspIRCd::Match(*gateway, webirc) ? MOD_RES_PASSTHRU : MOD_RES_DENY;
 326         }
 327
 328         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
 329         {
 330                 for(CGIHostlist::iterator iter = cmd.Hosts.begin(); iter != cmd.Hosts.end(); iter++)
 331                 {
 332                         if(InspIRCd::Match(user->host, iter->hostmask, ascii_case_insensitive_map) || InspIRCd::MatchCIDR(user->GetIPString(), iter->hostmask, ascii_case_insensitive_map))
 333                         {
 334                                 // Deal with it...
 335                                 if(iter->type == PASS)
 336                                 {
 337                                         CheckPass(user); // We do nothing if it fails so...
 338                                         user->CheckLines(true);
 339                                 }
 340                                 else if(iter->type == PASSFIRST && !CheckPass(user))
 341                                 {
 342                                         // If the password lookup failed, try the ident
 343                                         CheckIdent(user);       // If this fails too, do nothing
 344                                         user->CheckLines(true);
 345                                 }
 346                                 else if(iter->type == IDENT)
 347                                 {
 348                                         CheckIdent(user); // Nothing on failure.
 349                                         user->CheckLines(true);
 350                                 }
 351                                 else if(iter->type == IDENTFIRST && !CheckIdent(user))
 352                                 {
 353                                         // If the ident lookup fails, try the password.
 354                                         CheckPass(user);
 355                                         user->CheckLines(true);
 356                                 }
 357                                 else if(iter->type == WEBIRC)
 358                                 {
 359                                         // We don't need to do anything here
 360                                 }
 361                                 return MOD_RES_PASSTHRU;
 362                         }
 363                 }
 364                 return MOD_RES_PASSTHRU;
 365         }
 366
 367         bool CheckPass(LocalUser* user)
 368         {
 369                 if(IsValidHost(user->password))
 370                 {
 371                         HandleIdentOrPass(user, user->password, true);
 372                         user->password.clear();
 373                         return true;
 374                 }
 375
 376                 return false;
 377         }
 378
 379         bool CheckIdent(LocalUser* user)
 380         {
 381                 const char* ident;
 382                 in_addr newip;
 383
 384                 if (user->ident.length() == 8)
 385                         ident = user->ident.c_str();
 386                 else if (user->ident.length() == 9 && user->ident[0] == '~')
 387                         ident = user->ident.c_str() + 1;
 388                 else
 389                         return false;
 390
 391                 errno = 0;
 392                 unsigned long ipaddr = strtoul(ident, NULL, 16);
 393                 if (errno)
 394                         return false;
 395                 newip.s_addr = htonl(ipaddr);
 396                 std::string newipstr(inet_ntoa(newip));
 397
 398                 user->ident = "~cgiirc";
 399                 HandleIdentOrPass(user, newipstr, false);
 400
 401                 return true;
 402         }
 403
 404         bool IsValidHost(const std::string &host)
 405         {
 406                 if(!host.size() || host.size() > ServerInstance->Config->Limits.MaxHost)
 407                         return false;
 408
 409                 for(unsigned int i = 0; i < host.size(); i++)
 410                 {
 411                         if(     ((host[i] >= '0') && (host[i] <= '9')) ||
 412                                         ((host[i] >= 'A') && (host[i] <= 'Z')) ||
 413                                         ((host[i] >= 'a') && (host[i] <= 'z')) ||
 414                                         ((host[i] == '-') && (i > 0) && (i+1 < host.size()) && (host[i-1] != '.') && (host[i+1] != '.')) ||
 415                                         ((host[i] == '.') && (i > 0) && (i+1 < host.size())) )
 416
 417                                 continue;
 418                         else
 419                                 return false;
 420                 }
 421
 422                 return true;
 423         }
 424
 425         Version GetVersion() CXX11_OVERRIDE
 426         {
 427                 return Version("Change user's hosts connecting from known CGI:IRC hosts",VF_VENDOR);
 428         }
 429 };
 430
 431 MODULE_INIT(ModuleCgiIRC)