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