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