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