src/modules/m_dnsbl.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2006-2008 Robin Burchell <robin+git@viroteck.net>
   6  *   Copyright (C) 2007 Craig Edwards <craigedwards@brainbox.cc>
   7  *   Copyright (C) 2006-2007 Dennis Friis <peavey@inspircd.org>
   8  *   Copyright (C) 2007 John Brooks <john.brooks@dereferenced.net>
   9  *
  10  * This file is part of InspIRCd.  InspIRCd is free software: you can
  11  * redistribute it and/or modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation, version 2.
  13  *
  14  * This program is distributed in the hope that it will be useful, but WITHOUT
  15  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  16  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23
  24 #include "inspircd.h"
  25 #include "xline.h"
  26
  27 #ifndef WINDOWS
  28 #include <sys/types.h>
  29 #include <sys/socket.h>
  30 #include <netinet/in.h>
  31 #include <arpa/inet.h>
  32 #endif
  33
  34 /* $ModDesc: Provides handling of DNS blacklists */
  35
  36 /* Class holding data for a single entry */
  37 class DNSBLConfEntry
  38 {
  39         public:
  40                 enum EnumBanaction { I_UNKNOWN, I_KILL, I_ZLINE, I_KLINE, I_GLINE, I_MARK };
  41                 enum EnumType { A_RECORD, A_BITMASK };
  42                 std::string name, ident, host, domain, reason;
  43                 EnumBanaction banaction;
  44                 EnumType type;
  45                 long duration;
  46                 int bitmask;
  47                 unsigned char records[256];
  48                 unsigned long stats_hits, stats_misses;
  49                 DNSBLConfEntry(): type(A_BITMASK),duration(86400),bitmask(0),stats_hits(0), stats_misses(0) {}
  50                 ~DNSBLConfEntry() { }
  51 };
  52
  53
  54 /** Resolver for CGI:IRC hostnames encoded in ident/GECOS
  55  */
  56 class DNSBLResolver : public Resolver
  57 {
  58         std::string theiruid;
  59         LocalStringExt& nameExt;
  60         LocalIntExt& countExt;
  61         DNSBLConfEntry *ConfEntry;
  62
  63  public:
  64
  65         DNSBLResolver(Module *me, LocalStringExt& match, LocalIntExt& ctr, const std::string &hostname, LocalUser* u, DNSBLConfEntry *conf, bool &cached)
  66                 : Resolver(hostname, DNS_QUERY_A, cached, me), theiruid(u->uuid), nameExt(match), countExt(ctr), ConfEntry(conf)
  67         {
  68         }
  69
  70         /* Note: This may be called multiple times for multiple A record results */
  71         virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached)
  72         {
  73                 /* Check the user still exists */
  74                 LocalUser* them = (LocalUser*)ServerInstance->FindUUID(theiruid);
  75                 if (them)
  76                 {
  77                         int i = countExt.get(them);
  78                         if (i)
  79                                 countExt.set(them, i - 1);
  80                         // Now we calculate the bitmask: 256*(256*(256*a+b)+c)+d
  81                         if(result.length())
  82                         {
  83                                 unsigned int bitmask = 0, record = 0;
  84                                 bool match = false;
  85                                 in_addr resultip;
  86
  87                                 inet_aton(result.c_str(), &resultip);
  88
  89                                 switch (ConfEntry->type)
  90                                 {
  91                                         case DNSBLConfEntry::A_BITMASK:
  92                                                 bitmask = resultip.s_addr >> 24; /* Last octet (network byte order) */
  93                                                 bitmask &= ConfEntry->bitmask;
  94                                                 match = (bitmask != 0);
  95                                         break;
  96                                         case DNSBLConfEntry::A_RECORD:
  97                                                 record = resultip.s_addr >> 24; /* Last octet */
  98                                                 match = (ConfEntry->records[record] == 1);
  99                                         break;
 100                                 }
 101
 102                                 if (match)
 103                                 {
 104                                         std::string reason = ConfEntry->reason;
 105                                         std::string::size_type x = reason.find("%ip%");
 106                                         while (x != std::string::npos)
 107                                         {
 108                                                 reason.erase(x, 4);
 109                                                 reason.insert(x, them->GetIPString());
 110                                                 x = reason.find("%ip%");
 111                                         }
 112
 113                                         ConfEntry->stats_hits++;
 114
 115                                         switch (ConfEntry->banaction)
 116                                         {
 117                                                 case DNSBLConfEntry::I_KILL:
 118                                                 {
 119                                                         ServerInstance->Users->QuitUser(them, "Killed (" + reason + ")");
 120                                                         break;
 121                                                 }
 122                                                 case DNSBLConfEntry::I_MARK:
 123                                                 {
 124                                                         if (!ConfEntry->ident.empty())
 125                                                         {
 126                                                                 them->WriteServ("304 " + them->nick + " :Your ident has been set to " + ConfEntry->ident + " because you matched " + reason);
 127                                                                 them->ChangeIdent(ConfEntry->ident.c_str());
 128                                                         }
 129
 130                                                         if (!ConfEntry->host.empty())
 131                                                         {
 132                                                                 them->WriteServ("304 " + them->nick + " :Your host has been set to " + ConfEntry->host + " because you matched " + reason);
 133                                                                 them->ChangeDisplayedHost(ConfEntry->host.c_str());
 134                                                         }
 135
 136                                                         nameExt.set(them, ConfEntry->name);
 137                                                         break;
 138                                                 }
 139                                                 case DNSBLConfEntry::I_KLINE:
 140                                                 {
 141                                                         KLine* kl = new KLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(),
 142                                                                         "*", them->GetIPString());
 143                                                         if (ServerInstance->XLines->AddLine(kl,NULL))
 144                                                         {
 145                                                                 std::string timestr = ServerInstance->TimeString(kl->expiry);
 146                                                                 ServerInstance->SNO->WriteGlobalSno('x',"K:line added due to DNSBL match on *@%s to expire on %s: %s",
 147                                                                         them->GetIPString(), timestr.c_str(), reason.c_str());
 148                                                                 ServerInstance->XLines->ApplyLines();
 149                                                         }
 150                                                         else
 151                                                                 delete kl;
 152                                                         break;
 153                                                 }
 154                                                 case DNSBLConfEntry::I_GLINE:
 155                                                 {
 156                                                         GLine* gl = new GLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(),
 157                                                                         "*", them->GetIPString());
 158                                                         if (ServerInstance->XLines->AddLine(gl,NULL))
 159                                                         {
 160                                                                 std::string timestr = ServerInstance->TimeString(gl->expiry);
 161                                                                 ServerInstance->SNO->WriteGlobalSno('x',"G:line added due to DNSBL match on *@%s to expire on %s: %s",
 162                                                                         them->GetIPString(), timestr.c_str(), reason.c_str());
 163                                                                 ServerInstance->XLines->ApplyLines();
 164                                                         }
 165                                                         else
 166                                                                 delete gl;
 167                                                         break;
 168                                                 }
 169                                                 case DNSBLConfEntry::I_ZLINE:
 170                                                 {
 171                                                         ZLine* zl = new ZLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(),
 172                                                                         them->GetIPString());
 173                                                         if (ServerInstance->XLines->AddLine(zl,NULL))
 174                                                         {
 175                                                                 std::string timestr = ServerInstance->TimeString(zl->expiry);
 176                                                                 ServerInstance->SNO->WriteGlobalSno('x',"Z:line added due to DNSBL match on *@%s to expire on %s: %s",
 177                                                                         them->GetIPString(), timestr.c_str(), reason.c_str());
 178                                                                 ServerInstance->XLines->ApplyLines();
 179                                                         }
 180                                                         else
 181                                                                 delete zl;
 182                                                         break;
 183                                                 }
 184                                                 case DNSBLConfEntry::I_UNKNOWN:
 185                                                 {
 186                                                         break;
 187                                                 }
 188                                                 break;
 189                                         }
 190
 191                                         ServerInstance->SNO->WriteGlobalSno('a', "Connecting user %s%s detected as being on a DNS blacklist (%s) with result %d", them->nick.empty() ? "<unknown>" : "", them->GetFullRealHost().c_str(), ConfEntry->domain.c_str(), (ConfEntry->type==DNSBLConfEntry::A_BITMASK) ? bitmask : record);
 192                                 }
 193                                 else
 194                                         ConfEntry->stats_misses++;
 195                         }
 196                         else
 197                                 ConfEntry->stats_misses++;
 198                 }
 199         }
 200
 201         virtual void OnError(ResolverError e, const std::string &errormessage)
 202         {
 203                 LocalUser* them = (LocalUser*)ServerInstance->FindUUID(theiruid);
 204                 if (them)
 205                 {
 206                         int i = countExt.get(them);
 207                         if (i)
 208                                 countExt.set(them, i - 1);
 209                 }
 210         }
 211
 212         virtual ~DNSBLResolver()
 213         {
 214         }
 215 };
 216
 217 class ModuleDNSBL : public Module
 218 {
 219         std::vector<DNSBLConfEntry *> DNSBLConfEntries;
 220         LocalStringExt nameExt;
 221         LocalIntExt countExt;
 222
 223         /*
 224          *      Convert a string to EnumBanaction
 225          */
 226         DNSBLConfEntry::EnumBanaction str2banaction(const std::string &action)
 227         {
 228                 if(action.compare("KILL")==0)
 229                         return DNSBLConfEntry::I_KILL;
 230                 if(action.compare("KLINE")==0)
 231                         return DNSBLConfEntry::I_KLINE;
 232                 if(action.compare("ZLINE")==0)
 233                         return DNSBLConfEntry::I_ZLINE;
 234                 if(action.compare("GLINE")==0)
 235                         return DNSBLConfEntry::I_GLINE;
 236                 if(action.compare("MARK")==0)
 237                         return DNSBLConfEntry::I_MARK;
 238
 239                 return DNSBLConfEntry::I_UNKNOWN;
 240         }
 241  public:
 242         ModuleDNSBL() : nameExt("dnsbl_match", this), countExt("dnsbl_pending", this) { }
 243
 244         void init()
 245         {
 246                 ReadConf();
 247                 ServerInstance->Modules->AddService(nameExt);
 248                 ServerInstance->Modules->AddService(countExt);
 249                 Implementation eventlist[] = { I_OnRehash, I_OnSetUserIP, I_OnStats, I_OnSetConnectClass, I_OnCheckReady };
 250                 ServerInstance->Modules->Attach(eventlist, this, 5);
 251         }
 252
 253         virtual ~ModuleDNSBL()
 254         {
 255                 ClearEntries();
 256         }
 257
 258         Version GetVersion()
 259         {
 260                 return Version("Provides handling of DNS blacklists", VF_VENDOR);
 261         }
 262
 263         /** Clear entries and free the mem it was using
 264          */
 265         void ClearEntries()
 266         {
 267                 for (std::vector<DNSBLConfEntry *>::iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); i++)
 268                         delete *i;
 269                 DNSBLConfEntries.clear();
 270         }
 271
 272         /** Fill our conf vector with data
 273          */
 274         void ReadConf()
 275         {
 276                 ClearEntries();
 277
 278                 ConfigTagList dnsbls = ServerInstance->Config->ConfTags("dnsbl");
 279                 for(ConfigIter i = dnsbls.first; i != dnsbls.second; ++i)
 280                 {
 281                         ConfigTag* tag = i->second;
 282                         DNSBLConfEntry *e = new DNSBLConfEntry();
 283
 284                         e->name = tag->getString("name");
 285                         e->ident = tag->getString("ident");
 286                         e->host = tag->getString("host");
 287                         e->reason = tag->getString("reason");
 288                         e->domain = tag->getString("domain");
 289
 290                         if (tag->getString("type") == "bitmask")
 291                         {
 292                                 e->type = DNSBLConfEntry::A_BITMASK;
 293                                 e->bitmask = tag->getInt("bitmask");
 294                         }
 295                         else
 296                         {
 297                                 memset(e->records, 0, sizeof(e->records));
 298                                 e->type = DNSBLConfEntry::A_RECORD;
 299                                 irc::portparser portrange(tag->getString("records"), false);
 300                                 long item = -1;
 301                                 while ((item = portrange.GetToken()))
 302                                         e->records[item] = 1;
 303                         }
 304
 305                         e->banaction = str2banaction(tag->getString("action"));
 306                         e->duration = ServerInstance->Duration(tag->getString("duration", "60"));
 307
 308                         /* Use portparser for record replies */
 309
 310                         /* yeah, logic here is a little messy */
 311                         if ((e->bitmask <= 0) && (DNSBLConfEntry::A_BITMASK == e->type))
 312                         {
 313                                 std::string location = tag->getTagLocation();
 314                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): invalid bitmask", location.c_str());
 315                         }
 316                         else if (e->name.empty())
 317                         {
 318                                 std::string location = tag->getTagLocation();
 319                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid name", location.c_str());
 320                         }
 321                         else if (e->domain.empty())
 322                         {
 323                                 std::string location = tag->getTagLocation();
 324                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid domain", location.c_str());
 325                         }
 326                         else if (e->banaction == DNSBLConfEntry::I_UNKNOWN)
 327                         {
 328                                 std::string location = tag->getTagLocation();
 329                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid banaction", location.c_str());
 330                         }
 331                         else if (e->duration <= 0)
 332                         {
 333                                 std::string location = tag->getTagLocation();
 334                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid duration", location.c_str());
 335                         }
 336                         else
 337                         {
 338                                 if (e->reason.empty())
 339                                 {
 340                                         std::string location = tag->getTagLocation();
 341                                         ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): empty reason, using defaults", location.c_str());
 342                                         e->reason = "Your IP has been blacklisted.";
 343                                 }
 344
 345                                 /* add it, all is ok */
 346                                 DNSBLConfEntries.push_back(e);
 347                                 continue;
 348                         }
 349
 350                         /* delete and drop it, error somewhere */
 351                         delete e;
 352                 }
 353         }
 354
 355         void OnRehash(User* user)
 356         {
 357                 ReadConf();
 358         }
 359
 360         void OnSetUserIP(LocalUser* user)
 361         {
 362                 if (user->exempt)
 363                         return;
 364
 365                 unsigned char a, b, c, d;
 366                 char reversedipbuf[128];
 367                 std::string reversedip;
 368
 369                 if (user->client_sa.sa.sa_family != AF_INET)
 370                         return;
 371
 372                 d = (unsigned char) (user->client_sa.in4.sin_addr.s_addr >> 24) & 0xFF;
 373                 c = (unsigned char) (user->client_sa.in4.sin_addr.s_addr >> 16) & 0xFF;
 374                 b = (unsigned char) (user->client_sa.in4.sin_addr.s_addr >> 8) & 0xFF;
 375                 a = (unsigned char) user->client_sa.in4.sin_addr.s_addr & 0xFF;
 376
 377                 snprintf(reversedipbuf, 128, "%d.%d.%d.%d", d, c, b, a);
 378                 reversedip = std::string(reversedipbuf);
 379
 380                 // For each DNSBL, we will run through this lookup
 381                 unsigned int i = 0;
 382                 while (i < DNSBLConfEntries.size())
 383                 {
 384                         // Fill hostname with a dnsbl style host (d.c.b.a.domain.tld)
 385                         std::string hostname = reversedip + "." + DNSBLConfEntries[i]->domain;
 386
 387                         /* now we'd need to fire off lookups for `hostname'. */
 388                         bool cached;
 389                         DNSBLResolver *r = new DNSBLResolver(this, nameExt, countExt, hostname, user, DNSBLConfEntries[i], cached);
 390                         ServerInstance->AddResolver(r, cached);
 391                         i++;
 392                 }
 393                 countExt.set(user, i);
 394         }
 395
 396         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass)
 397         {
 398                 std::string dnsbl;
 399                 if (!myclass->config->readString("dnsbl", dnsbl))
 400                         return MOD_RES_PASSTHRU;
 401                 std::string* match = nameExt.get(user);
 402                 std::string myname = match ? *match : "";
 403                 if (dnsbl == myname)
 404                         return MOD_RES_PASSTHRU;
 405                 return MOD_RES_DENY;
 406         }
 407
 408         ModResult OnCheckReady(LocalUser *user)
 409         {
 410                 if (countExt.get(user))
 411                         return MOD_RES_DENY;
 412                 return MOD_RES_PASSTHRU;
 413         }
 414
 415         ModResult OnStats(char symbol, User* user, string_list &results)
 416         {
 417                 if (symbol != 'd')
 418                         return MOD_RES_PASSTHRU;
 419
 420                 unsigned long total_hits = 0, total_misses = 0;
 421
 422                 for (std::vector<DNSBLConfEntry*>::iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); i++)
 423                 {
 424                         total_hits += (*i)->stats_hits;
 425                         total_misses += (*i)->stats_misses;
 426
 427                         results.push_back(std::string(ServerInstance->Config->ServerName.c_str()) + " 304 " + user->nick + " :DNSBLSTATS DNSbl \"" + (*i)->name + "\" had " +
 428                                         ConvToStr((*i)->stats_hits) + " hits and " + ConvToStr((*i)->stats_misses) + " misses");
 429                 }
 430
 431                 results.push_back(std::string(ServerInstance->Config->ServerName.c_str()) + " 304 " + user->nick + " :DNSBLSTATS Total hits: " + ConvToStr(total_hits));
 432                 results.push_back(std::string(ServerInstance->Config->ServerName.c_str()) + " 304 " + user->nick + " :DNSBLSTATS Total misses: " + ConvToStr(total_misses));
 433
 434                 return MOD_RES_PASSTHRU;
 435         }
 436 };
 437
 438 MODULE_INIT(ModuleDNSBL)