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
  33 /** Holds a CGI site's details
  34  */
  35 class CGIhost
  36 {
  37 public:
  38         std::string hostmask;
  39         CGItype type;
  40         std::string password;
  41
  42         CGIhost(const std::string &mask, CGItype t, const std::string &spassword)
  43         : hostmask(mask), type(t), password(spassword)
  44         {
  45         }
  46 };
  47 typedef std::vector<CGIhost> CGIHostlist;
  48
  49 /*
  50  * WEBIRC
  51  *  This is used for the webirc method of CGIIRC auth, and is (really) the best way to do these things.
  52  *  Syntax: WEBIRC password client hostname ip
  53  *  Where password is a shared key, client is the name of the "client" and version (e.g. cgiirc), hostname
  54  *  is the resolved host of the client issuing the command and IP is the real IP of the client.
  55  *
  56  * How it works:
  57  *  To tie in with the rest of cgiirc module, and to avoid race conditions, /webirc is only processed locally
  58  *  and simply sets metadata on the user, which is later decoded on full connect to give something meaningful.
  59  */
  60 class CommandWebirc : public Command
  61 {
  62  public:
  63         bool notify;
  64         StringExtItem realhost;
  65         StringExtItem realip;
  66         LocalStringExt webirc_hostname;
  67         LocalStringExt webirc_ip;
  68
  69         CGIHostlist Hosts;
  70         CommandWebirc(Module* Creator)
  71                 : Command(Creator, "WEBIRC", 4),
  72                   realhost("cgiirc_realhost", Creator), realip("cgiirc_realip", Creator),
  73                   webirc_hostname("cgiirc_webirc_hostname", Creator), webirc_ip("cgiirc_webirc_ip", Creator)
  74                 {
  75                         works_before_reg = true;
  76                         this->syntax = "password client hostname ip";
  77                 }
  78                 CmdResult Handle(const std::vector<std::string> &parameters, User *user)
  79                 {
  80                         if(user->registered == REG_ALL)
  81                                 return CMD_FAILURE;
  82
  83                         for(CGIHostlist::iterator iter = Hosts.begin(); iter != Hosts.end(); iter++)
  84                         {
  85                                 if(InspIRCd::Match(user->host, iter->hostmask, ascii_case_insensitive_map) || InspIRCd::MatchCIDR(user->GetIPString(), iter->hostmask, ascii_case_insensitive_map))
  86                                 {
  87                                         if(iter->type == WEBIRC && parameters[0] == iter->password)
  88                                         {
  89                                                 realhost.set(user, user->host);
  90                                                 realip.set(user, user->GetIPString());
  91
  92                                                 bool host_ok = (parameters[2].length() <= ServerInstance->Config->Limits.MaxHost);
  93                                                 const std::string& newhost = (host_ok ? parameters[2] : parameters[3]);
  94
  95                                                 if (notify)
  96                                                         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());
  97
  98                                                 // 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
  99                                                 if (host_ok)
 100                                                         webirc_hostname.set(user, parameters[2]);
 101                                                 else
 102                                                         webirc_hostname.unset(user);
 103
 104                                                 webirc_ip.set(user, parameters[3]);
 105                                                 return CMD_SUCCESS;
 106                                         }
 107                                 }
 108                         }
 109
 110                         ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s tried to use WEBIRC, but didn't match any configured webirc blocks.", user->GetFullRealHost().c_str());
 111                         return CMD_FAILURE;
 112                 }
 113 };
 114
 115
 116 /** Resolver for CGI:IRC hostnames encoded in ident/GECOS
 117  */
 118 class CGIResolver : public DNS::Request
 119 {
 120         std::string typ;
 121         std::string theiruid;
 122         LocalIntExt& waiting;
 123         bool notify;
 124  public:
 125         CGIResolver(DNS::Manager *mgr, Module* me, bool NotifyOpers, const std::string &source, LocalUser* u,
 126                         const std::string &ttype, LocalIntExt& ext)
 127                 : DNS::Request(mgr, me, source, DNS::QUERY_PTR), typ(ttype), theiruid(u->uuid),
 128                 waiting(ext), notify(NotifyOpers)
 129         {
 130         }
 131
 132         void OnLookupComplete(const DNS::Query *r) CXX11_OVERRIDE
 133         {
 134                 /* Check the user still exists */
 135                 User* them = ServerInstance->FindUUID(theiruid);
 136                 if ((them) && (!them->quitting))
 137                 {
 138                         LocalUser* lu = IS_LOCAL(them);
 139                         if (!lu)
 140                                 return;
 141
 142                         const DNS::ResourceRecord &ans_record = r->answers[0];
 143                         if (ans_record.rdata.empty() || ans_record.rdata.length() > ServerInstance->Config->Limits.MaxHost)
 144                                 return;
 145
 146                         if (notify)
 147                                 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());
 148
 149                         them->host = them->dhost = ans_record.rdata;
 150                         them->InvalidateCache();
 151                         lu->CheckLines(true);
 152                 }
 153         }
 154
 155         void OnError(const DNS::Query *r) CXX11_OVERRIDE
 156         {
 157                 if (!notify)
 158                         return;
 159
 160                 User* them = ServerInstance->FindUUID(theiruid);
 161                 if ((them) && (!them->quitting))
 162                 {
 163                         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());
 164                 }
 165         }
 166
 167         ~CGIResolver()
 168         {
 169                 User* them = ServerInstance->FindUUID(theiruid);
 170                 if (!them)
 171                         return;
 172                 int count = waiting.get(them);
 173                 if (count)
 174                         waiting.set(them, count - 1);
 175         }
 176 };
 177
 178 class ModuleCgiIRC : public Module
 179 {
 180         CommandWebirc cmd;
 181         LocalIntExt waiting;
 182         dynamic_reference<DNS::Manager> DNS;
 183
 184         static void RecheckClass(LocalUser* user)
 185         {
 186                 user->MyClass = NULL;
 187                 user->SetClass();
 188                 user->CheckClass();
 189         }
 190
 191         static void ChangeIP(LocalUser* user, const std::string& newip)
 192         {
 193                 ServerInstance->Users->RemoveCloneCounts(user);
 194                 user->SetClientIP(newip.c_str());
 195                 ServerInstance->Users->AddLocalClone(user);
 196                 ServerInstance->Users->AddGlobalClone(user);
 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", 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("CONFIG", LOG_DEFAULT, "m_cgiirc: 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("CONFIG", 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("CONFIG", 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                 std::string *webirc_ip = cmd.webirc_ip.get(user);
 297                 if (!webirc_ip)
 298                         return MOD_RES_PASSTHRU;
 299
 300                 ChangeIP(user, *webirc_ip);
 301
 302                 std::string* webirc_hostname = cmd.webirc_hostname.get(user);
 303                 user->host = user->dhost = (webirc_hostname ? *webirc_hostname : user->GetIPString());
 304
 305                 RecheckClass(user);
 306                 if (user->quitting)
 307                         return MOD_RES_DENY;
 308
 309                 user->CheckLines(true);
 310                 if (user->quitting)
 311                         return MOD_RES_DENY;
 312
 313                 cmd.webirc_hostname.unset(user);
 314                 cmd.webirc_ip.unset(user);
 315
 316                 return MOD_RES_PASSTHRU;
 317         }
 318
 319         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
 320         {
 321                 for(CGIHostlist::iterator iter = cmd.Hosts.begin(); iter != cmd.Hosts.end(); iter++)
 322                 {
 323                         if(InspIRCd::Match(user->host, iter->hostmask, ascii_case_insensitive_map) || InspIRCd::MatchCIDR(user->GetIPString(), iter->hostmask, ascii_case_insensitive_map))
 324                         {
 325                                 // Deal with it...
 326                                 if(iter->type == PASS)
 327                                 {
 328                                         CheckPass(user); // We do nothing if it fails so...
 329                                         user->CheckLines(true);
 330                                 }
 331                                 else if(iter->type == PASSFIRST && !CheckPass(user))
 332                                 {
 333                                         // If the password lookup failed, try the ident
 334                                         CheckIdent(user);       // If this fails too, do nothing
 335                                         user->CheckLines(true);
 336                                 }
 337                                 else if(iter->type == IDENT)
 338                                 {
 339                                         CheckIdent(user); // Nothing on failure.
 340                                         user->CheckLines(true);
 341                                 }
 342                                 else if(iter->type == IDENTFIRST && !CheckIdent(user))
 343                                 {
 344                                         // If the ident lookup fails, try the password.
 345                                         CheckPass(user);
 346                                         user->CheckLines(true);
 347                                 }
 348                                 else if(iter->type == WEBIRC)
 349                                 {
 350                                         // We don't need to do anything here
 351                                 }
 352                                 return MOD_RES_PASSTHRU;
 353                         }
 354                 }
 355                 return MOD_RES_PASSTHRU;
 356         }
 357
 358         bool CheckPass(LocalUser* user)
 359         {
 360                 if(IsValidHost(user->password))
 361                 {
 362                         HandleIdentOrPass(user, user->password, true);
 363                         user->password.clear();
 364                         return true;
 365                 }
 366
 367                 return false;
 368         }
 369
 370         bool CheckIdent(LocalUser* user)
 371         {
 372                 const char* ident;
 373                 in_addr newip;
 374
 375                 if (user->ident.length() == 8)
 376                         ident = user->ident.c_str();
 377                 else if (user->ident.length() == 9 && user->ident[0] == '~')
 378                         ident = user->ident.c_str() + 1;
 379                 else
 380                         return false;
 381
 382                 errno = 0;
 383                 unsigned long ipaddr = strtoul(ident, NULL, 16);
 384                 if (errno)
 385                         return false;
 386                 newip.s_addr = htonl(ipaddr);
 387                 std::string newipstr(inet_ntoa(newip));
 388
 389                 user->ident = "~cgiirc";
 390                 HandleIdentOrPass(user, newipstr, false);
 391
 392                 return true;
 393         }
 394
 395         bool IsValidHost(const std::string &host)
 396         {
 397                 if(!host.size() || host.size() > ServerInstance->Config->Limits.MaxHost)
 398                         return false;
 399
 400                 for(unsigned int i = 0; i < host.size(); i++)
 401                 {
 402                         if(     ((host[i] >= '0') && (host[i] <= '9')) ||
 403                                         ((host[i] >= 'A') && (host[i] <= 'Z')) ||
 404                                         ((host[i] >= 'a') && (host[i] <= 'z')) ||
 405                                         ((host[i] == '-') && (i > 0) && (i+1 < host.size()) && (host[i-1] != '.') && (host[i+1] != '.')) ||
 406                                         ((host[i] == '.') && (i > 0) && (i+1 < host.size())) )
 407
 408                                 continue;
 409                         else
 410                                 return false;
 411                 }
 412
 413                 return true;
 414         }
 415
 416         Version GetVersion() CXX11_OVERRIDE
 417         {
 418                 return Version("Change user's hosts connecting from known CGI:IRC hosts",VF_VENDOR);
 419         }
 420 };
 421
 422 MODULE_INIT(ModuleCgiIRC)