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                         allow_empty_last_param = false;
  83                         works_before_reg = true;
  84                         this->syntax = "password gateway hostname ip";
  85                 }
  86                 CmdResult Handle(const std::vector<std::string> &parameters, User *user)
  87                 {
  88                         if(user->registered == REG_ALL)
  89                                 return CMD_FAILURE;
  90
  91                         irc::sockets::sockaddrs ipaddr;
  92                         if (!irc::sockets::aptosa(parameters[3], 0, ipaddr))
  93                         {
  94                                 IS_LOCAL(user)->CommandFloodPenalty += 5000;
  95                                 ServerInstance->SNO->WriteGlobalSno('a', "Connecting user %s tried to use WEBIRC but gave an invalid IP address.", user->GetFullRealHost().c_str());
  96                                 return CMD_FAILURE;
  97                         }
  98
  99                         for(CGIHostlist::iterator iter = Hosts.begin(); iter != Hosts.end(); iter++)
 100                         {
 101                                 if(InspIRCd::Match(user->host, iter->hostmask, ascii_case_insensitive_map) || InspIRCd::MatchCIDR(user->GetIPString(), iter->hostmask, ascii_case_insensitive_map))
 102                                 {
 103                                         if(iter->type == WEBIRC && parameters[0] == iter->password)
 104                                         {
 105                                                 gateway.set(user, parameters[1]);
 106                                                 realhost.set(user, user->host);
 107                                                 realip.set(user, user->GetIPString());
 108
 109                                                 // 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
 110                                                 bool host_ok = (parameters[2].length() <= ServerInstance->Config->Limits.MaxHost);
 111                                                 const std::string& newhost = (host_ok ? parameters[2] : parameters[3]);
 112
 113                                                 if (notify)
 114                                                         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());
 115
 116                                                 // Where the magic happens - change their IP
 117                                                 ChangeIP(user, parameters[3]);
 118                                                 // And follow this up by changing their host
 119                                                 user->host = user->dhost = newhost;
 120                                                 user->InvalidateCache();
 121
 122                                                 return CMD_SUCCESS;
 123                                         }
 124                                 }
 125                         }
 126
 127                         IS_LOCAL(user)->CommandFloodPenalty += 5000;
 128                         ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s tried to use WEBIRC, but didn't match any configured webirc blocks.", user->GetFullRealHost().c_str());
 129                         return CMD_FAILURE;
 130                 }
 131 };
 132
 133
 134 /** Resolver for CGI:IRC hostnames encoded in ident/GECOS
 135  */
 136 class CGIResolver : public DNS::Request
 137 {
 138         std::string typ;
 139         std::string theiruid;
 140         LocalIntExt& waiting;
 141         bool notify;
 142  public:
 143         CGIResolver(DNS::Manager *mgr, Module* me, bool NotifyOpers, const std::string &source, LocalUser* u,
 144                         const std::string &ttype, LocalIntExt& ext)
 145                 : DNS::Request(mgr, me, source, DNS::QUERY_PTR), typ(ttype), theiruid(u->uuid),
 146                 waiting(ext), notify(NotifyOpers)
 147         {
 148         }
 149
 150         void OnLookupComplete(const DNS::Query *r) CXX11_OVERRIDE
 151         {
 152                 /* Check the user still exists */
 153                 User* them = ServerInstance->FindUUID(theiruid);
 154                 if ((them) && (!them->quitting))
 155                 {
 156                         LocalUser* lu = IS_LOCAL(them);
 157                         if (!lu)
 158                                 return;
 159
 160                         const DNS::ResourceRecord &ans_record = r->answers[0];
 161                         if (ans_record.rdata.empty() || ans_record.rdata.length() > ServerInstance->Config->Limits.MaxHost)
 162                                 return;
 163
 164                         if (notify)
 165                                 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());
 166
 167                         them->host = them->dhost = ans_record.rdata;
 168                         them->InvalidateCache();
 169                         lu->CheckLines(true);
 170                 }
 171         }
 172
 173         void OnError(const DNS::Query *r) CXX11_OVERRIDE
 174         {
 175                 if (!notify)
 176                         return;
 177
 178                 User* them = ServerInstance->FindUUID(theiruid);
 179                 if ((them) && (!them->quitting))
 180                 {
 181                         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());
 182                 }
 183         }
 184
 185         ~CGIResolver()
 186         {
 187                 User* them = ServerInstance->FindUUID(theiruid);
 188                 if (!them)
 189                         return;
 190                 int count = waiting.get(them);
 191                 if (count)
 192                         waiting.set(them, count - 1);
 193         }
 194 };
 195
 196 class ModuleCgiIRC : public Module
 197 {
 198         CommandWebirc cmd;
 199         LocalIntExt waiting;
 200         dynamic_reference<DNS::Manager> DNS;
 201
 202         static void RecheckClass(LocalUser* user)
 203         {
 204                 user->MyClass = NULL;
 205                 user->SetClass();
 206                 user->CheckClass();
 207         }
 208
 209         void HandleIdentOrPass(LocalUser* user, const std::string& newip, bool was_pass)
 210         {
 211                 cmd.realhost.set(user, user->host);
 212                 cmd.realip.set(user, user->GetIPString());
 213                 ChangeIP(user, newip);
 214                 user->host = user->dhost = user->GetIPString();
 215                 user->InvalidateCache();
 216                 RecheckClass(user);
 217
 218                 // Don't create the resolver if the core couldn't put the user in a connect class or when dns is disabled
 219                 if (user->quitting || !DNS || !user->MyClass->resolvehostnames)
 220                         return;
 221
 222                 CGIResolver* r = new CGIResolver(*this->DNS, this, cmd.notify, newip, user, (was_pass ? "PASS" : "IDENT"), waiting);
 223                 try
 224                 {
 225                         waiting.set(user, waiting.get(user) + 1);
 226                         this->DNS->Process(r);
 227                 }
 228                 catch (DNS::Exception &ex)
 229                 {
 230                         int count = waiting.get(user);
 231                         if (count)
 232                                 waiting.set(user, count - 1);
 233                         delete r;
 234                         if (cmd.notify)
 235                                  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());
 236                 }
 237         }
 238
 239 public:
 240         ModuleCgiIRC()
 241                 : cmd(this)
 242                 , waiting("cgiirc-delay", ExtensionItem::EXT_USER, this)
 243                 , DNS(this, "DNS")
 244         {
 245         }
 246
 247         void init() CXX11_OVERRIDE
 248         {
 249                 ServerInstance->SNO->EnableSnomask('w', "CGIIRC");
 250         }
 251
 252         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 253         {
 254                 cmd.Hosts.clear();
 255
 256                 // Do we send an oper notice when a CGI:IRC has their host changed?
 257                 cmd.notify = ServerInstance->Config->ConfValue("cgiirc")->getBool("opernotice", true);
 258
 259                 ConfigTagList tags = ServerInstance->Config->ConfTags("cgihost");
 260                 for (ConfigIter i = tags.first; i != tags.second; ++i)
 261                 {
 262                         ConfigTag* tag = i->second;
 263                         std::string hostmask = tag->getString("mask"); // An allowed CGI:IRC host
 264                         std::string type = tag->getString("type"); // What type of user-munging we do on this host.
 265                         std::string password = tag->getString("password");
 266
 267                         if(hostmask.length())
 268                         {
 269                                 if (type == "webirc" && password.empty())
 270                                 {
 271                                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Missing password in config: %s", hostmask.c_str());
 272                                 }
 273                                 else
 274                                 {
 275                                         CGItype cgitype;
 276                                         if (type == "pass")
 277                                                 cgitype = PASS;
 278                                         else if (type == "ident")
 279                                                 cgitype = IDENT;
 280                                         else if (type == "passfirst")
 281                                                 cgitype = PASSFIRST;
 282                                         else if (type == "webirc")
 283                                                 cgitype = WEBIRC;
 284                                         else
 285                                         {
 286                                                 cgitype = PASS;
 287                                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Invalid <cgihost:type> value in config: %s, setting it to \"pass\"", type.c_str());
 288                                         }
 289
 290                                         cmd.Hosts.push_back(CGIhost(hostmask, cgitype, password));
 291                                 }
 292                         }
 293                         else
 294                         {
 295                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Invalid <cgihost:mask> value in config: %s", hostmask.c_str());
 296                                 continue;
 297                         }
 298                 }
 299         }
 300
 301         ModResult OnCheckReady(LocalUser *user) CXX11_OVERRIDE
 302         {
 303                 if (waiting.get(user))
 304                         return MOD_RES_DENY;
 305
 306                 if (!cmd.realip.get(user))
 307                         return MOD_RES_PASSTHRU;
 308
 309                 RecheckClass(user);
 310                 if (user->quitting)
 311                         return MOD_RES_DENY;
 312
 313                 user->CheckLines(true);
 314                 if (user->quitting)
 315                         return MOD_RES_DENY;
 316
 317                 return MOD_RES_PASSTHRU;
 318         }
 319
 320         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE
 321         {
 322                 // If <connect:webirc> is not set then we have nothing to do.
 323                 const std::string webirc = myclass->config->getString("webirc");
 324                 if (webirc.empty())
 325                         return MOD_RES_PASSTHRU;
 326
 327                 // If the user is not connecting via a WebIRC gateway then they
 328                 // cannot match this connect class.
 329                 const std::string* gateway = cmd.gateway.get(user);
 330                 if (!gateway)
 331                         return MOD_RES_DENY;
 332
 333                 // If the gateway matches the <connect:webirc> constraint then
 334                 // allow the check to continue. Otherwise, reject it.
 335                 return InspIRCd::Match(*gateway, webirc) ? MOD_RES_PASSTHRU : MOD_RES_DENY;
 336         }
 337
 338         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
 339         {
 340                 for(CGIHostlist::iterator iter = cmd.Hosts.begin(); iter != cmd.Hosts.end(); iter++)
 341                 {
 342                         if(InspIRCd::Match(user->host, iter->hostmask, ascii_case_insensitive_map) || InspIRCd::MatchCIDR(user->GetIPString(), iter->hostmask, ascii_case_insensitive_map))
 343                         {
 344                                 // Deal with it...
 345                                 if(iter->type == PASS)
 346                                 {
 347                                         CheckPass(user); // We do nothing if it fails so...
 348                                         user->CheckLines(true);
 349                                 }
 350                                 else if(iter->type == PASSFIRST && !CheckPass(user))
 351                                 {
 352                                         // If the password lookup failed, try the ident
 353                                         CheckIdent(user);       // If this fails too, do nothing
 354                                         user->CheckLines(true);
 355                                 }
 356                                 else if(iter->type == IDENT)
 357                                 {
 358                                         CheckIdent(user); // Nothing on failure.
 359                                         user->CheckLines(true);
 360                                 }
 361                                 else if(iter->type == IDENTFIRST && !CheckIdent(user))
 362                                 {
 363                                         // If the ident lookup fails, try the password.
 364                                         CheckPass(user);
 365                                         user->CheckLines(true);
 366                                 }
 367                                 else if(iter->type == WEBIRC)
 368                                 {
 369                                         // We don't need to do anything here
 370                                 }
 371                                 return MOD_RES_PASSTHRU;
 372                         }
 373                 }
 374                 return MOD_RES_PASSTHRU;
 375         }
 376
 377         bool CheckPass(LocalUser* user)
 378         {
 379                 if(IsValidHost(user->password))
 380                 {
 381                         HandleIdentOrPass(user, user->password, true);
 382                         user->password.clear();
 383                         return true;
 384                 }
 385
 386                 return false;
 387         }
 388
 389         bool CheckIdent(LocalUser* user)
 390         {
 391                 const char* ident;
 392                 in_addr newip;
 393
 394                 if (user->ident.length() == 8)
 395                         ident = user->ident.c_str();
 396                 else if (user->ident.length() == 9 && user->ident[0] == '~')
 397                         ident = user->ident.c_str() + 1;
 398                 else
 399                         return false;
 400
 401                 errno = 0;
 402                 unsigned long ipaddr = strtoul(ident, NULL, 16);
 403                 if (errno)
 404                         return false;
 405                 newip.s_addr = htonl(ipaddr);
 406                 std::string newipstr(inet_ntoa(newip));
 407
 408                 user->ident = "~cgiirc";
 409                 HandleIdentOrPass(user, newipstr, false);
 410
 411                 return true;
 412         }
 413
 414         bool IsValidHost(const std::string &host)
 415         {
 416                 if(!host.size() || host.size() > ServerInstance->Config->Limits.MaxHost)
 417                         return false;
 418
 419                 for(unsigned int i = 0; i < host.size(); i++)
 420                 {
 421                         if(     ((host[i] >= '0') && (host[i] <= '9')) ||
 422                                         ((host[i] >= 'A') && (host[i] <= 'Z')) ||
 423                                         ((host[i] >= 'a') && (host[i] <= 'z')) ||
 424                                         ((host[i] == '-') && (i > 0) && (i+1 < host.size()) && (host[i-1] != '.') && (host[i+1] != '.')) ||
 425                                         ((host[i] == '.') && (i > 0) && (i+1 < host.size())) )
 426
 427                                 continue;
 428                         else
 429                                 return false;
 430                 }
 431
 432                 return true;
 433         }
 434
 435         Version GetVersion() CXX11_OVERRIDE
 436         {
 437                 return Version("Change user's hosts connecting from known CGI:IRC hosts",VF_VENDOR);
 438         }
 439 };
 440
 441 MODULE_INIT(ModuleCgiIRC)