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         DNSBLConfEntry *ConfEntry;
  50
  51  public:
  52
  53         DNSBLResolver(Module *me, const std::string &hostname, LocalUser* u, DNSBLConfEntry *conf, bool &cached)
  54                 : Resolver(hostname, DNS_QUERY_A, cached, me)
  55         {
  56                 theiruid = u->uuid;
  57                 ConfEntry = conf;
  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                 User* them = ServerInstance->FindUUID(theiruid);
  65                 if (them)
  66                 {
  67                         // Now we calculate the bitmask: 256*(256*(256*a+b)+c)+d
  68                         if(result.length())
  69                         {
  70                                 unsigned int bitmask = 0, record = 0;
  71                                 bool match = false;
  72                                 in_addr resultip;
  73
  74                                 inet_aton(result.c_str(), &resultip);
  75
  76                                 switch (ConfEntry->type)
  77                                 {
  78                                         case DNSBLConfEntry::A_BITMASK:
  79                                                 bitmask = resultip.s_addr >> 24; /* Last octet (network byte order) */
  80                                                 bitmask &= ConfEntry->bitmask;
  81                                                 match = (bitmask != 0);
  82                                         break;
  83                                         case DNSBLConfEntry::A_RECORD:
  84                                                 record = resultip.s_addr >> 24; /* Last octet */
  85                                                 match = (ConfEntry->records[record] == 1);
  86                                         break;
  87                                 }
  88
  89                                 if (match)
  90                                 {
  91                                         std::string reason = ConfEntry->reason;
  92                                         std::string::size_type x = reason.find("%ip%");
  93                                         while (x != std::string::npos)
  94                                         {
  95                                                 reason.erase(x, 4);
  96                                                 reason.insert(x, them->GetIPString());
  97                                                 x = reason.find("%ip%");
  98                                         }
  99
 100                                         ConfEntry->stats_hits++;
 101
 102                                         switch (ConfEntry->banaction)
 103                                         {
 104                                                 case DNSBLConfEntry::I_KILL:
 105                                                 {
 106                                                         ServerInstance->Users->QuitUser(them, std::string("Killed (") + reason + ")");
 107                                                         break;
 108                                                 }
 109                                                 case DNSBLConfEntry::I_MARK:
 110                                                 {
 111                                                         if (!ConfEntry->ident.empty())
 112                                                         {
 113                                                                 them->WriteServ("304 " + them->nick + " :Your ident has been set to " + ConfEntry->ident + " because you matched " + reason);
 114                                                                 them->ChangeIdent(ConfEntry->ident.c_str());
 115                                                         }
 116
 117                                                         if (!ConfEntry->host.empty())
 118                                                         {
 119                                                                 them->WriteServ("304 " + them->nick + " :Your host has been set to " + ConfEntry->host + " because you matched " + reason);
 120                                                                 them->ChangeDisplayedHost(ConfEntry->host.c_str());
 121                                                         }
 122
 123                                                         break;
 124                                                 }
 125                                                 case DNSBLConfEntry::I_KLINE:
 126                                                 {
 127                                                         KLine* kl = new KLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(),
 128                                                                         "*", them->GetIPString());
 129                                                         if (ServerInstance->XLines->AddLine(kl,NULL))
 130                                                         {
 131                                                                 ServerInstance->SNO->WriteGlobalSno('x',"K:line added due to DNSBL match on *@%s to expire on %s: %s",
 132                                                                         them->GetIPString(), ServerInstance->TimeString(kl->expiry).c_str(), reason.c_str());
 133                                                                 ServerInstance->XLines->ApplyLines();
 134                                                         }
 135                                                         else
 136                                                                 delete kl;
 137                                                         break;
 138                                                 }
 139                                                 case DNSBLConfEntry::I_GLINE:
 140                                                 {
 141                                                         GLine* gl = new GLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(),
 142                                                                         "*", them->GetIPString());
 143                                                         if (ServerInstance->XLines->AddLine(gl,NULL))
 144                                                         {
 145                                                                 ServerInstance->SNO->WriteGlobalSno('x',"G:line added due to DNSBL match on *@%s to expire on %s: %s",
 146                                                                         them->GetIPString(), ServerInstance->TimeString(gl->expiry).c_str(), reason.c_str());
 147                                                                 ServerInstance->XLines->ApplyLines();
 148                                                         }
 149                                                         else
 150                                                                 delete gl;
 151                                                         break;
 152                                                 }
 153                                                 case DNSBLConfEntry::I_ZLINE:
 154                                                 {
 155                                                         ZLine* zl = new ZLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(),
 156                                                                         them->GetIPString());
 157                                                         if (ServerInstance->XLines->AddLine(zl,NULL))
 158                                                         {
 159                                                                 ServerInstance->SNO->WriteGlobalSno('x',"Z:line added due to DNSBL match on *@%s to expire on %s: %s",
 160                                                                         them->GetIPString(), ServerInstance->TimeString(zl->expiry).c_str(), reason.c_str());
 161                                                                 ServerInstance->XLines->ApplyLines();
 162                                                         }
 163                                                         else
 164                                                                 delete zl;
 165                                                         break;
 166                                                 }
 167                                                 case DNSBLConfEntry::I_UNKNOWN:
 168                                                 {
 169                                                         break;
 170                                                 }
 171                                                 break;
 172                                         }
 173
 174                                         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);
 175                                 }
 176                                 else
 177                                         ConfEntry->stats_misses++;
 178                         }
 179                         else
 180                                 ConfEntry->stats_misses++;
 181                 }
 182         }
 183
 184         virtual void OnError(ResolverError e, const std::string &errormessage)
 185         {
 186         }
 187
 188         virtual ~DNSBLResolver()
 189         {
 190         }
 191 };
 192
 193 class ModuleDNSBL : public Module
 194 {
 195  private:
 196         std::vector<DNSBLConfEntry *> DNSBLConfEntries;
 197
 198         /*
 199          *      Convert a string to EnumBanaction
 200          */
 201         DNSBLConfEntry::EnumBanaction str2banaction(const std::string &action)
 202         {
 203                 if(action.compare("KILL")==0)
 204                         return DNSBLConfEntry::I_KILL;
 205                 if(action.compare("KLINE")==0)
 206                         return DNSBLConfEntry::I_KLINE;
 207                 if(action.compare("ZLINE")==0)
 208                         return DNSBLConfEntry::I_ZLINE;
 209                 if(action.compare("GLINE")==0)
 210                         return DNSBLConfEntry::I_GLINE;
 211                 if(action.compare("MARK")==0)
 212                         return DNSBLConfEntry::I_MARK;
 213
 214                 return DNSBLConfEntry::I_UNKNOWN;
 215         }
 216  public:
 217         ModuleDNSBL()   {
 218                 ReadConf();
 219                 Implementation eventlist[] = { I_OnRehash, I_OnUserRegister, I_OnStats };
 220                 ServerInstance->Modules->Attach(eventlist, this, 3);
 221         }
 222
 223         virtual ~ModuleDNSBL()
 224         {
 225                 ClearEntries();
 226         }
 227
 228         virtual Version GetVersion()
 229         {
 230                 return Version("Provides handling of DNS blacklists", VF_VENDOR);
 231         }
 232
 233
 234         /** Clear entries and free the mem it was using
 235          */
 236         void ClearEntries()
 237         {
 238                 for (std::vector<DNSBLConfEntry *>::iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); i++)
 239                         delete *i;
 240                 DNSBLConfEntries.clear();
 241         }
 242
 243         /** Fill our conf vector with data
 244          */
 245         virtual void ReadConf()
 246         {
 247                 ConfigReader MyConf;
 248                 ClearEntries();
 249
 250                 for (int i=0; i< MyConf.Enumerate("dnsbl"); i++)
 251                 {
 252                         DNSBLConfEntry *e = new DNSBLConfEntry();
 253
 254                         e->name = MyConf.ReadValue("dnsbl", "name", i);
 255                         e->ident = MyConf.ReadValue("dnsbl", "ident", i);
 256                         e->host = MyConf.ReadValue("dnsbl", "host", i);
 257                         e->reason = MyConf.ReadValue("dnsbl", "reason", i);
 258                         e->domain = MyConf.ReadValue("dnsbl", "domain", i);
 259
 260                         if (MyConf.ReadValue("dnsbl", "type", i) == "bitmask")
 261                         {
 262                                 e->type = DNSBLConfEntry::A_BITMASK;
 263                                 e->bitmask = MyConf.ReadInteger("dnsbl", "bitmask", i, false);
 264                         }
 265                         else
 266                         {
 267                                 memset(e->records, 0, sizeof(e->records));
 268                                 e->type = DNSBLConfEntry::A_RECORD;
 269                                 irc::portparser portrange(MyConf.ReadValue("dnsbl", "records", i), false);
 270                                 long item = -1;
 271                                 while ((item = portrange.GetToken()))
 272                                         e->records[item] = 1;
 273                         }
 274
 275                         e->banaction = str2banaction(MyConf.ReadValue("dnsbl", "action", i));
 276                         e->duration = ServerInstance->Duration(MyConf.ReadValue("dnsbl", "duration", "60", i));
 277
 278                         /* Use portparser for record replies */
 279
 280                         /* yeah, logic here is a little messy */
 281                         if ((e->bitmask <= 0) && (DNSBLConfEntry::A_BITMASK == e->type))
 282                         {
 283                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(#%d): invalid bitmask",i);
 284                         }
 285                         else if (e->name.empty())
 286                         {
 287                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(#%d): Invalid name",i);
 288                         }
 289                         else if (e->domain.empty())
 290                         {
 291                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(#%d): Invalid domain",i);
 292                         }
 293                         else if (e->banaction == DNSBLConfEntry::I_UNKNOWN)
 294                         {
 295                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(#%d): Invalid banaction", i);
 296                         }
 297                         else if (e->duration <= 0)
 298                         {
 299                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(#%d): Invalid duration", i);
 300                         }
 301                         else
 302                         {
 303                                 if (e->reason.empty())
 304                                 {
 305                                         ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(#%d): empty reason, using defaults",i);
 306                                         e->reason = "Your IP has been blacklisted.";
 307                                 }
 308
 309                                 /* add it, all is ok */
 310                                 DNSBLConfEntries.push_back(e);
 311                                 continue;
 312                         }
 313
 314                         /* delete and drop it, error somewhere */
 315                         delete e;
 316                 }
 317         }
 318
 319         virtual void OnRehash(User* user)
 320         {
 321                 ReadConf();
 322         }
 323
 324         virtual ModResult OnUserRegister(LocalUser* user)
 325         {
 326                 /* following code taken from bopm, reverses an IP address. */
 327                 struct in_addr in;
 328                 unsigned char a, b, c, d;
 329                 char reversedipbuf[128];
 330                 std::string reversedip;
 331                 bool success;
 332
 333                 success = inet_aton(user->GetIPString(), &in);
 334
 335                 if (!success)
 336                         return MOD_RES_PASSTHRU;
 337
 338                 d = (unsigned char) (in.s_addr >> 24) & 0xFF;
 339                 c = (unsigned char) (in.s_addr >> 16) & 0xFF;
 340                 b = (unsigned char) (in.s_addr >> 8) & 0xFF;
 341                 a = (unsigned char) in.s_addr & 0xFF;
 342
 343                 snprintf(reversedipbuf, 128, "%d.%d.%d.%d", d, c, b, a);
 344                 reversedip = std::string(reversedipbuf);
 345
 346                 // For each DNSBL, we will run through this lookup
 347                 for (std::vector<DNSBLConfEntry *>::iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); i++)
 348                 {
 349                         // Fill hostname with a dnsbl style host (d.c.b.a.domain.tld)
 350                         std::string hostname = reversedip + "." + (*i)->domain;
 351
 352                         /* now we'd need to fire off lookups for `hostname'. */
 353                         bool cached;
 354                         DNSBLResolver *r = new DNSBLResolver(this, hostname, user, *i, cached);
 355                         ServerInstance->AddResolver(r, cached);
 356                 }
 357
 358                 /* don't do anything with this hot potato */
 359                 return MOD_RES_PASSTHRU;
 360         }
 361
 362         virtual ModResult OnStats(char symbol, User* user, string_list &results)
 363         {
 364                 if (symbol != 'd')
 365                         return MOD_RES_PASSTHRU;
 366
 367                 unsigned long total_hits = 0, total_misses = 0;
 368
 369                 for (std::vector<DNSBLConfEntry*>::iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); i++)
 370                 {
 371                         total_hits += (*i)->stats_hits;
 372                         total_misses += (*i)->stats_misses;
 373
 374                         results.push_back(std::string(ServerInstance->Config->ServerName.c_str()) + " 304 " + user->nick + " :DNSBLSTATS DNSbl \"" + (*i)->name + "\" had " +
 375                                         ConvToStr((*i)->stats_hits) + " hits and " + ConvToStr((*i)->stats_misses) + " misses");
 376                 }
 377
 378                 results.push_back(std::string(ServerInstance->Config->ServerName.c_str()) + " 304 " + user->nick + " :DNSBLSTATS Total hits: " + ConvToStr(total_hits));
 379                 results.push_back(std::string(ServerInstance->Config->ServerName.c_str()) + " 304 " + user->nick + " :DNSBLSTATS Total misses: " + ConvToStr(total_misses));
 380
 381                 return MOD_RES_PASSTHRU;
 382         }
 383 };
 384
 385 MODULE_INIT(ModuleDNSBL)