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