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->AddClone(user);
 196         }
 197
 198         void HandleIdentOrPass(LocalUser* user, const std::string& newip, bool was_pass)
 199         {
 200                 cmd.realhost.set(user, user->host);
 201                 cmd.realip.set(user, user->GetIPString());
 202                 ChangeIP(user, newip);
 203                 user->host = user->dhost = user->GetIPString();
 204                 user->InvalidateCache();
 205                 RecheckClass(user);
 206
 207                 // Don't create the resolver if the core couldn't put the user in a connect class or when dns is disabled
 208                 if (user->quitting || !DNS || !user->MyClass->resolvehostnames)
 209                         return;
 210
 211                 CGIResolver* r = new CGIResolver(*this->DNS, this, cmd.notify, newip, user, (was_pass ? "PASS" : "IDENT"), waiting);
 212                 try
 213                 {
 214                         waiting.set(user, waiting.get(user) + 1);
 215                         this->DNS->Process(r);
 216                 }
 217                 catch (DNS::Exception &ex)
 218                 {
 219                         int count = waiting.get(user);
 220                         if (count)
 221                                 waiting.set(user, count - 1);
 222                         delete r;
 223                         if (cmd.notify)
 224                                  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());
 225                 }
 226         }
 227
 228 public:
 229         ModuleCgiIRC()
 230                 : cmd(this)
 231                 , waiting("cgiirc-delay", this)
 232                 , DNS(this, "DNS")
 233         {
 234         }
 235
 236         void init() CXX11_OVERRIDE
 237         {
 238                 ServerInstance->SNO->EnableSnomask('w', "CGIIRC");
 239         }
 240
 241         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 242         {
 243                 cmd.Hosts.clear();
 244
 245                 // Do we send an oper notice when a CGI:IRC has their host changed?
 246                 cmd.notify = ServerInstance->Config->ConfValue("cgiirc")->getBool("opernotice", true);
 247
 248                 ConfigTagList tags = ServerInstance->Config->ConfTags("cgihost");
 249                 for (ConfigIter i = tags.first; i != tags.second; ++i)
 250                 {
 251                         ConfigTag* tag = i->second;
 252                         std::string hostmask = tag->getString("mask"); // An allowed CGI:IRC host
 253                         std::string type = tag->getString("type"); // What type of user-munging we do on this host.
 254                         std::string password = tag->getString("password");
 255
 256                         if(hostmask.length())
 257                         {
 258                                 if (type == "webirc" && password.empty())
 259                                 {
 260                                         ServerInstance->Logs->Log("CONFIG", LOG_DEFAULT, "m_cgiirc: Missing password in config: %s", hostmask.c_str());
 261                                 }
 262                                 else
 263                                 {
 264                                         CGItype cgitype;
 265                                         if (type == "pass")
 266                                                 cgitype = PASS;
 267                                         else if (type == "ident")
 268                                                 cgitype = IDENT;
 269                                         else if (type == "passfirst")
 270                                                 cgitype = PASSFIRST;
 271                                         else if (type == "webirc")
 272                                                 cgitype = WEBIRC;
 273                                         else
 274                                         {
 275                                                 cgitype = PASS;
 276                                                 ServerInstance->Logs->Log("CONFIG", LOG_DEFAULT, "Invalid <cgihost:type> value in config: %s, setting it to \"pass\"", type.c_str());
 277                                         }
 278
 279                                         cmd.Hosts.push_back(CGIhost(hostmask, cgitype, password));
 280                                 }
 281                         }
 282                         else
 283                         {
 284                                 ServerInstance->Logs->Log("CONFIG", LOG_DEFAULT, "Invalid <cgihost:mask> value in config: %s", hostmask.c_str());
 285                                 continue;
 286                         }
 287                 }
 288         }
 289
 290         ModResult OnCheckReady(LocalUser *user) CXX11_OVERRIDE
 291         {
 292                 if (waiting.get(user))
 293                         return MOD_RES_DENY;
 294
 295                 std::string *webirc_ip = cmd.webirc_ip.get(user);
 296                 if (!webirc_ip)
 297                         return MOD_RES_PASSTHRU;
 298
 299                 ChangeIP(user, *webirc_ip);
 300
 301                 std::string* webirc_hostname = cmd.webirc_hostname.get(user);
 302                 user->host = user->dhost = (webirc_hostname ? *webirc_hostname : user->GetIPString());
 303
 304                 RecheckClass(user);
 305                 if (user->quitting)
 306                         return MOD_RES_DENY;
 307
 308                 user->CheckLines(true);
 309                 if (user->quitting)
 310                         return MOD_RES_DENY;
 311
 312                 cmd.webirc_hostname.unset(user);
 313                 cmd.webirc_ip.unset(user);
 314
 315                 return MOD_RES_PASSTHRU;
 316         }
 317
 318         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
 319         {
 320                 for(CGIHostlist::iterator iter = cmd.Hosts.begin(); iter != cmd.Hosts.end(); iter++)
 321                 {
 322                         if(InspIRCd::Match(user->host, iter->hostmask, ascii_case_insensitive_map) || InspIRCd::MatchCIDR(user->GetIPString(), iter->hostmask, ascii_case_insensitive_map))
 323                         {
 324                                 // Deal with it...
 325                                 if(iter->type == PASS)
 326                                 {
 327                                         CheckPass(user); // We do nothing if it fails so...
 328                                         user->CheckLines(true);
 329                                 }
 330                                 else if(iter->type == PASSFIRST && !CheckPass(user))
 331                                 {
 332                                         // If the password lookup failed, try the ident
 333                                         CheckIdent(user);       // If this fails too, do nothing
 334                                         user->CheckLines(true);
 335                                 }
 336                                 else if(iter->type == IDENT)
 337                                 {
 338                                         CheckIdent(user); // Nothing on failure.
 339                                         user->CheckLines(true);
 340                                 }
 341                                 else if(iter->type == IDENTFIRST && !CheckIdent(user))
 342                                 {
 343                                         // If the ident lookup fails, try the password.
 344                                         CheckPass(user);
 345                                         user->CheckLines(true);
 346                                 }
 347                                 else if(iter->type == WEBIRC)
 348                                 {
 349                                         // We don't need to do anything here
 350                                 }
 351                                 return MOD_RES_PASSTHRU;
 352                         }
 353                 }
 354                 return MOD_RES_PASSTHRU;
 355         }
 356
 357         bool CheckPass(LocalUser* user)
 358         {
 359                 if(IsValidHost(user->password))
 360                 {
 361                         HandleIdentOrPass(user, user->password, true);
 362                         user->password.clear();
 363                         return true;
 364                 }
 365
 366                 return false;
 367         }
 368
 369         bool CheckIdent(LocalUser* user)
 370         {
 371                 const char* ident;
 372                 in_addr newip;
 373
 374                 if (user->ident.length() == 8)
 375                         ident = user->ident.c_str();
 376                 else if (user->ident.length() == 9 && user->ident[0] == '~')
 377                         ident = user->ident.c_str() + 1;
 378                 else
 379                         return false;
 380
 381                 errno = 0;
 382                 unsigned long ipaddr = strtoul(ident, NULL, 16);
 383                 if (errno)
 384                         return false;
 385                 newip.s_addr = htonl(ipaddr);
 386                 std::string newipstr(inet_ntoa(newip));
 387
 388                 user->ident = "~cgiirc";
 389                 HandleIdentOrPass(user, newipstr, false);
 390
 391                 return true;
 392         }
 393
 394         bool IsValidHost(const std::string &host)
 395         {
 396                 if(!host.size() || host.size() > ServerInstance->Config->Limits.MaxHost)
 397                         return false;
 398
 399                 for(unsigned int i = 0; i < host.size(); i++)
 400                 {
 401                         if(     ((host[i] >= '0') && (host[i] <= '9')) ||
 402                                         ((host[i] >= 'A') && (host[i] <= 'Z')) ||
 403                                         ((host[i] >= 'a') && (host[i] <= 'z')) ||
 404                                         ((host[i] == '-') && (i > 0) && (i+1 < host.size()) && (host[i-1] != '.') && (host[i+1] != '.')) ||
 405                                         ((host[i] == '.') && (i > 0) && (i+1 < host.size())) )
 406
 407                                 continue;
 408                         else
 409                                 return false;
 410                 }
 411
 412                 return true;
 413         }
 414
 415         Version GetVersion() CXX11_OVERRIDE
 416         {
 417                 return Version("Change user's hosts connecting from known CGI:IRC hosts",VF_VENDOR);
 418         }
 419 };
 420
 421 MODULE_INIT(ModuleCgiIRC)