src/modules/m_dnsbl.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2010 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *            the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 #include "inspircd.h"
  15 #include "xline.h"
  16
  17 #ifndef WINDOWS
  18 #include <sys/types.h>
  19 #include <sys/socket.h>
  20 #include <netinet/in.h>
  21 #include <arpa/inet.h>
  22 #endif
  23
  24 /* $ModDesc: Provides handling of DNS blacklists */
  25
  26 /* Class holding data for a single entry */
  27 class DNSBLConfEntry
  28 {
  29         public:
  30                 enum EnumBanaction { I_UNKNOWN, I_KILL, I_ZLINE, I_KLINE, I_GLINE, I_MARK };
  31                 enum EnumType { A_RECORD, A_BITMASK };
  32                 std::string name, ident, host, domain, reason;
  33                 EnumBanaction banaction;
  34                 EnumType type;
  35                 long duration;
  36                 int bitmask;
  37                 unsigned char records[256];
  38                 unsigned long stats_hits, stats_misses;
  39                 DNSBLConfEntry(): type(A_BITMASK),duration(86400),bitmask(0),stats_hits(0), stats_misses(0) {}
  40                 ~DNSBLConfEntry() { }
  41 };
  42
  43
  44 /** Resolver for CGI:IRC hostnames encoded in ident/GECOS
  45  */
  46 class DNSBLResolver : public Resolver
  47 {
  48         std::string theiruid;
  49         LocalStringExt& nameExt;
  50         LocalIntExt& countExt;
  51         DNSBLConfEntry *ConfEntry;
  52
  53  public:
  54
  55         DNSBLResolver(Module *me, LocalStringExt& match, LocalIntExt& ctr, const std::string &hostname, LocalUser* u, DNSBLConfEntry *conf, bool &cached)
  56                 : Resolver(hostname, DNS_QUERY_A, cached, me), theiruid(u->uuid), nameExt(match), countExt(ctr), ConfEntry(conf)
  57         {
  58         }
  59
  60         /* Note: This may be called multiple times for multiple A record results */
  61         virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached)
  62         {
  63                 /* Check the user still exists */
  64                 LocalUser* them = (LocalUser*)ServerInstance->FindUUID(theiruid);
  65                 if (them)
  66                 {
  67                         int i = countExt.get(them);
  68                         if (i)
  69                                 countExt.set(them, i - 1);
  70                         // Now we calculate the bitmask: 256*(256*(256*a+b)+c)+d
  71                         if(result.length())
  72                         {
  73                                 unsigned int bitmask = 0, record = 0;
  74                                 bool match = false;
  75                                 in_addr resultip;
  76
  77                                 inet_aton(result.c_str(), &resultip);
  78
  79                                 switch (ConfEntry->type)
  80                                 {
  81                                         case DNSBLConfEntry::A_BITMASK:
  82                                                 bitmask = resultip.s_addr >> 24; /* Last octet (network byte order) */
  83                                                 bitmask &= ConfEntry->bitmask;
  84                                                 match = (bitmask != 0);
  85                                         break;
  86                                         case DNSBLConfEntry::A_RECORD:
  87                                                 record = resultip.s_addr >> 24; /* Last octet */
  88                                                 match = (ConfEntry->records[record] == 1);
  89                                         break;
  90                                 }
  91
  92                                 if (match)
  93                                 {
  94                                         std::string reason = ConfEntry->reason;
  95                                         std::string::size_type x = reason.find("%ip%");
  96                                         while (x != std::string::npos)
  97                                         {
  98                                                 reason.erase(x, 4);
  99                                                 reason.insert(x, them->GetIPString());
 100                                                 x = reason.find("%ip%");
 101                                         }
 102
 103                                         ConfEntry->stats_hits++;
 104
 105                                         switch (ConfEntry->banaction)
 106                                         {
 107                                                 case DNSBLConfEntry::I_KILL:
 108                                                 {
 109                                                         ServerInstance->Users->QuitUser(them, std::string("Killed (") + reason + ")");
 110                                                         break;
 111                                                 }
 112                                                 case DNSBLConfEntry::I_MARK:
 113                                                 {
 114                                                         if (!ConfEntry->ident.empty())
 115                                                         {
 116                                                                 them->WriteServ("304 " + them->nick + " :Your ident has been set to " + ConfEntry->ident + " because you matched " + reason);
 117                                                                 them->ChangeIdent(ConfEntry->ident.c_str());
 118                                                         }
 119
 120                                                         if (!ConfEntry->host.empty())
 121                                                         {
 122                                                                 them->WriteServ("304 " + them->nick + " :Your host has been set to " + ConfEntry->host + " because you matched " + reason);
 123                                                                 them->ChangeDisplayedHost(ConfEntry->host.c_str());
 124                                                         }
 125
 126                                                         nameExt.set(them, ConfEntry->name);
 127                                                         break;
 128                                                 }
 129                                                 case DNSBLConfEntry::I_KLINE:
 130                                                 {
 131                                                         KLine* kl = new KLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(),
 132                                                                         "*", them->GetIPString());
 133                                                         if (ServerInstance->XLines->AddLine(kl,NULL))
 134                                                         {
 135                                                                 ServerInstance->SNO->WriteGlobalSno('x',"K:line added due to DNSBL match on *@%s to expire on %s: %s",
 136                                                                         them->GetIPString(), ServerInstance->TimeString(kl->expiry).c_str(), reason.c_str());
 137                                                                 ServerInstance->XLines->ApplyLines();
 138                                                         }
 139                                                         else
 140                                                                 delete kl;
 141                                                         break;
 142                                                 }
 143                                                 case DNSBLConfEntry::I_GLINE:
 144                                                 {
 145                                                         GLine* gl = new GLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(),
 146                                                                         "*", them->GetIPString());
 147                                                         if (ServerInstance->XLines->AddLine(gl,NULL))
 148                                                         {
 149                                                                 ServerInstance->SNO->WriteGlobalSno('x',"G:line added due to DNSBL match on *@%s to expire on %s: %s",
 150                                                                         them->GetIPString(), ServerInstance->TimeString(gl->expiry).c_str(), reason.c_str());
 151                                                                 ServerInstance->XLines->ApplyLines();
 152                                                         }
 153                                                         else
 154                                                                 delete gl;
 155                                                         break;
 156                                                 }
 157                                                 case DNSBLConfEntry::I_ZLINE:
 158                                                 {
 159                                                         ZLine* zl = new ZLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(),
 160                                                                         them->GetIPString());
 161                                                         if (ServerInstance->XLines->AddLine(zl,NULL))
 162                                                         {
 163                                                                 ServerInstance->SNO->WriteGlobalSno('x',"Z:line added due to DNSBL match on *@%s to expire on %s: %s",
 164                                                                         them->GetIPString(), ServerInstance->TimeString(zl->expiry).c_str(), reason.c_str());
 165                                                                 ServerInstance->XLines->ApplyLines();
 166                                                         }
 167                                                         else
 168                                                                 delete zl;
 169                                                         break;
 170                                                 }
 171                                                 case DNSBLConfEntry::I_UNKNOWN:
 172                                                 {
 173                                                         break;
 174                                                 }
 175                                                 break;
 176                                         }
 177
 178                                         ServerInstance->SNO->WriteGlobalSno('a', "Connecting user %s detected as being on a DNS blacklist (%s) with result %d", them->GetFullRealHost().c_str(), ConfEntry->domain.c_str(), (ConfEntry->type==DNSBLConfEntry::A_BITMASK) ? bitmask : record);
 179                                 }
 180                                 else
 181                                         ConfEntry->stats_misses++;
 182                         }
 183                         else
 184                                 ConfEntry->stats_misses++;
 185                 }
 186         }
 187
 188         virtual void OnError(ResolverError e, const std::string &errormessage)
 189         {
 190                 LocalUser* them = (LocalUser*)ServerInstance->FindUUID(theiruid);
 191                 if (them)
 192                 {
 193                         int i = countExt.get(them);
 194                         if (i)
 195                                 countExt.set(them, i - 1);
 196                 }
 197         }
 198
 199         virtual ~DNSBLResolver()
 200         {
 201         }
 202 };
 203
 204 class ModuleDNSBL : public Module
 205 {
 206         std::vector<DNSBLConfEntry *> DNSBLConfEntries;
 207         LocalStringExt nameExt;
 208         LocalIntExt countExt;
 209
 210         /*
 211          *      Convert a string to EnumBanaction
 212          */
 213         DNSBLConfEntry::EnumBanaction str2banaction(const std::string &action)
 214         {
 215                 if(action.compare("KILL")==0)
 216                         return DNSBLConfEntry::I_KILL;
 217                 if(action.compare("KLINE")==0)
 218                         return DNSBLConfEntry::I_KLINE;
 219                 if(action.compare("ZLINE")==0)
 220                         return DNSBLConfEntry::I_ZLINE;
 221                 if(action.compare("GLINE")==0)
 222                         return DNSBLConfEntry::I_GLINE;
 223                 if(action.compare("MARK")==0)
 224                         return DNSBLConfEntry::I_MARK;
 225
 226                 return DNSBLConfEntry::I_UNKNOWN;
 227         }
 228  public:
 229         ModuleDNSBL() : nameExt("dnsbl_match", this), countExt("dnsbl_pending", this) { }
 230
 231         void init()
 232         {
 233                 ReadConf();
 234                 ServerInstance->Modules->AddService(nameExt);
 235                 ServerInstance->Modules->AddService(countExt);
 236                 Implementation eventlist[] = { I_OnRehash, I_OnUserInit, I_OnStats, I_OnSetConnectClass, I_OnCheckReady };
 237                 ServerInstance->Modules->Attach(eventlist, this, 5);
 238         }
 239
 240         virtual ~ModuleDNSBL()
 241         {
 242                 ClearEntries();
 243         }
 244
 245         Version GetVersion()
 246         {
 247                 return Version("Provides handling of DNS blacklists", VF_VENDOR);
 248         }
 249
 250         /** Clear entries and free the mem it was using
 251          */
 252         void ClearEntries()
 253         {
 254                 for (std::vector<DNSBLConfEntry *>::iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); i++)
 255                         delete *i;
 256                 DNSBLConfEntries.clear();
 257         }
 258
 259         /** Fill our conf vector with data
 260          */
 261         void ReadConf()
 262         {
 263                 ClearEntries();
 264
 265                 ConfigTagList dnsbls = ServerInstance->Config->ConfTags("dnsbl");
 266                 for(ConfigIter i = dnsbls.first; i != dnsbls.second; ++i)
 267                 {
 268                         ConfigTag* tag = i->second;
 269                         DNSBLConfEntry *e = new DNSBLConfEntry();
 270
 271                         e->name = tag->getString("name");
 272                         e->ident = tag->getString("ident");
 273                         e->host = tag->getString("host");
 274                         e->reason = tag->getString("reason");
 275                         e->domain = tag->getString("domain");
 276
 277                         if (tag->getString("type") == "bitmask")
 278                         {
 279                                 e->type = DNSBLConfEntry::A_BITMASK;
 280                                 e->bitmask = tag->getInt("bitmask");
 281                         }
 282                         else
 283                         {
 284                                 memset(e->records, 0, sizeof(e->records));
 285                                 e->type = DNSBLConfEntry::A_RECORD;
 286                                 irc::portparser portrange(tag->getString("records"), false);
 287                                 long item = -1;
 288                                 while ((item = portrange.GetToken()))
 289                                         e->records[item] = 1;
 290                         }
 291
 292                         e->banaction = str2banaction(tag->getString("action"));
 293                         e->duration = ServerInstance->Duration(tag->getString("duration", "60"));
 294
 295                         /* Use portparser for record replies */
 296
 297                         /* yeah, logic here is a little messy */
 298                         if ((e->bitmask <= 0) && (DNSBLConfEntry::A_BITMASK == e->type))
 299                         {
 300                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): invalid bitmask",tag->getTagLocation().c_str());
 301                         }
 302                         else if (e->name.empty())
 303                         {
 304                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid name",tag->getTagLocation().c_str());
 305                         }
 306                         else if (e->domain.empty())
 307                         {
 308                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid domain",tag->getTagLocation().c_str());
 309                         }
 310                         else if (e->banaction == DNSBLConfEntry::I_UNKNOWN)
 311                         {
 312                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid banaction",tag->getTagLocation().c_str());
 313                         }
 314                         else if (e->duration <= 0)
 315                         {
 316                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid duration",tag->getTagLocation().c_str());
 317                         }
 318                         else
 319                         {
 320                                 if (e->reason.empty())
 321                                 {
 322                                         ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): empty reason, using defaults",tag->getTagLocation().c_str());
 323                                         e->reason = "Your IP has been blacklisted.";
 324                                 }
 325
 326                                 /* add it, all is ok */
 327                                 DNSBLConfEntries.push_back(e);
 328                                 continue;
 329                         }
 330
 331                         /* delete and drop it, error somewhere */
 332                         delete e;
 333                 }
 334         }
 335
 336         void OnRehash(User* user)
 337         {
 338                 ReadConf();
 339         }
 340
 341         void OnUserInit(LocalUser* user)
 342         {
 343                 if (user->exempt)
 344                         return;
 345
 346                 /* following code taken from bopm, reverses an IP address. */
 347                 struct in_addr in;
 348                 unsigned char a, b, c, d;
 349                 char reversedipbuf[128];
 350                 std::string reversedip;
 351                 bool success;
 352
 353                 success = inet_aton(user->GetIPString(), &in);
 354
 355                 if (!success)
 356                         return;
 357
 358                 d = (unsigned char) (in.s_addr >> 24) & 0xFF;
 359                 c = (unsigned char) (in.s_addr >> 16) & 0xFF;
 360                 b = (unsigned char) (in.s_addr >> 8) & 0xFF;
 361                 a = (unsigned char) in.s_addr & 0xFF;
 362
 363                 snprintf(reversedipbuf, 128, "%d.%d.%d.%d", d, c, b, a);
 364                 reversedip = std::string(reversedipbuf);
 365
 366                 // For each DNSBL, we will run through this lookup
 367                 unsigned int i = 0;
 368                 while (i < DNSBLConfEntries.size())
 369                 {
 370                         // Fill hostname with a dnsbl style host (d.c.b.a.domain.tld)
 371                         std::string hostname = reversedip + "." + DNSBLConfEntries[i]->domain;
 372
 373                         /* now we'd need to fire off lookups for `hostname'. */
 374                         bool cached;
 375                         DNSBLResolver *r = new DNSBLResolver(this, nameExt, countExt, hostname, user, DNSBLConfEntries[i], cached);
 376                         ServerInstance->AddResolver(r, cached);
 377                         i++;
 378                 }
 379                 countExt.set(user, i);
 380         }
 381
 382         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass)
 383         {
 384                 std::string dnsbl;
 385                 if (!myclass->config->readString("dnsbl", dnsbl))
 386                         return MOD_RES_PASSTHRU;
 387                 std::string* match = nameExt.get(user);
 388                 std::string myname = match ? *match : "";
 389                 if (dnsbl == myname)
 390                         return MOD_RES_PASSTHRU;
 391                 return MOD_RES_DENY;
 392         }
 393
 394         ModResult OnCheckReady(LocalUser *user)
 395         {
 396                 if (countExt.get(user))
 397                         return MOD_RES_DENY;
 398                 return MOD_RES_PASSTHRU;
 399         }
 400
 401         ModResult OnStats(char symbol, User* user, string_list &results)
 402         {
 403                 if (symbol != 'd')
 404                         return MOD_RES_PASSTHRU;
 405
 406                 unsigned long total_hits = 0, total_misses = 0;
 407
 408                 for (std::vector<DNSBLConfEntry*>::iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); i++)
 409                 {
 410                         total_hits += (*i)->stats_hits;
 411                         total_misses += (*i)->stats_misses;
 412
 413                         results.push_back(std::string(ServerInstance->Config->ServerName.c_str()) + " 304 " + user->nick + " :DNSBLSTATS DNSbl \"" + (*i)->name + "\" had " +
 414                                         ConvToStr((*i)->stats_hits) + " hits and " + ConvToStr((*i)->stats_misses) + " misses");
 415                 }
 416
 417                 results.push_back(std::string(ServerInstance->Config->ServerName.c_str()) + " 304 " + user->nick + " :DNSBLSTATS Total hits: " + ConvToStr(total_hits));
 418                 results.push_back(std::string(ServerInstance->Config->ServerName.c_str()) + " 304 " + user->nick + " :DNSBLSTATS Total misses: " + ConvToStr(total_misses));
 419
 420                 return MOD_RES_PASSTHRU;
 421         }
 422 };
 423
 424 MODULE_INIT(ModuleDNSBL)