src/modules/m_dnsbl.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2007 InspIRCd Development Team
   6  * See: http://www.inspircd.org/wiki/index.php/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 #include "dns.h"
  17 #include "users.h"
  18 #include "channels.h"
  19 #include "modules.h"
  20
  21 #ifndef WINDOWS
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24 #include <netinet/in.h>
  25 #include <arpa/inet.h>
  26 #include <stdint.h>
  27 #endif
  28
  29 /* $ModDesc: Provides handling of DNS blacklists */
  30
  31 /* Class holding data for a single entry */
  32 class DNSBLConfEntry
  33 {
  34         public:
  35                 enum EnumBanaction { I_UNKNOWN, I_KILL, I_ZLINE, I_KLINE, I_GLINE };
  36                 std::string name, domain, reason;
  37                 EnumBanaction banaction;
  38                 long duration;
  39                 int bitmask;
  40                 unsigned long stats_hits, stats_misses;
  41                 DNSBLConfEntry(): duration(86400),bitmask(0),stats_hits(0), stats_misses(0) {}
  42                 ~DNSBLConfEntry() { }
  43 };
  44
  45
  46 /** Resolver for CGI:IRC hostnames encoded in ident/GECOS
  47  */
  48 class DNSBLResolver : public Resolver
  49 {
  50         int theirfd;
  51         userrec* them;
  52         DNSBLConfEntry *ConfEntry;
  53
  54  public:
  55
  56         DNSBLResolver(Module *me, InspIRCd *ServerInstance, const std::string &hostname, userrec* u, int userfd, DNSBLConfEntry *conf, bool &cached)
  57                 : Resolver(ServerInstance, hostname, DNS_QUERY_A, cached, me)
  58         {
  59                 theirfd = userfd;
  60                 them = u;
  61                 ConfEntry = conf;
  62         }
  63
  64         virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached)
  65         {
  66                 /* Check the user still exists */
  67                 if ((them) && (them == ServerInstance->SE->GetRef(theirfd)))
  68                 {
  69                         // Now we calculate the bitmask: 256*(256*(256*a+b)+c)+d
  70                         if(result.length())
  71                         {
  72                                 unsigned int bitmask = 0;
  73                                 bool show = false;
  74                                 in_addr resultip;
  75
  76                                 /* Convert the result to an in_addr (we can gaurantee we got ipv4)
  77                                  * Whoever did the loop that was here before, I AM CONFISCATING
  78                                  * YOUR CRACKPIPE. you know who you are. -- Brain
  79                                  */
  80                                 inet_aton(result.c_str(), &resultip);
  81                                 bitmask = resultip.s_addr >> 24; /* Last octet (network byte order */
  82
  83                                 bitmask &= ConfEntry->bitmask;
  84
  85                                 if (bitmask != 0)
  86                                 {
  87                                         std::string reason = ConfEntry->reason;
  88                                         std::string::size_type x = reason.find("%ip%");
  89                                         while (x != std::string::npos)
  90                                         {
  91                                                 reason.erase(x, 4);
  92                                                 reason.insert(x, them->GetIPString());
  93                                                 x = reason.find("%ip%");
  94                                         }
  95
  96                                         ConfEntry->stats_hits++;
  97
  98                                         switch (ConfEntry->banaction)
  99                                         {
 100                                                 case DNSBLConfEntry::I_KILL:
 101                                                 {
 102                                                         userrec::QuitUser(ServerInstance, them, std::string("Killed (") + reason + ")");
 103                                                         break;
 104                                                 }
 105                                                 case DNSBLConfEntry::I_KLINE:
 106                                                 {
 107                                                         std::string ban = std::string("*@") + them->GetIPString();
 108                                                         show = ServerInstance->XLines->add_kline(ConfEntry->duration, ServerInstance->Config->ServerName, reason.c_str(), ban.c_str());
 109                                                         FOREACH_MOD(I_OnAddKLine,OnAddKLine(ConfEntry->duration, NULL, reason, ban));
 110                                                         break;
 111                                                 }
 112                                                 case DNSBLConfEntry::I_GLINE:
 113                                                 {
 114                                                         std::string ban = std::string("*@") + them->GetIPString();
 115                                                         show = ServerInstance->XLines->add_gline(ConfEntry->duration, ServerInstance->Config->ServerName, reason.c_str(), ban.c_str());
 116                                                         FOREACH_MOD(I_OnAddGLine,OnAddGLine(ConfEntry->duration, NULL, reason, ban));
 117                                                         break;
 118                                                 }
 119                                                 case DNSBLConfEntry::I_ZLINE:
 120                                                 {
 121                                                         show = ServerInstance->XLines->add_zline(ConfEntry->duration, ServerInstance->Config->ServerName, reason.c_str(), them->GetIPString());
 122                                                         FOREACH_MOD(I_OnAddZLine,OnAddZLine(ConfEntry->duration, NULL, reason, them->GetIPString()));
 123                                                         break;
 124                                                 }
 125                                                 case DNSBLConfEntry::I_UNKNOWN:
 126                                                 {
 127                                                         break;
 128                                                 }
 129                                                 break;
 130                                         }
 131
 132                                         if (show)
 133                                                 ServerInstance->WriteOpers("*** Connecting user %s detected as being on a DNS blacklist (%s) with result %d", them->GetFullRealHost(), ConfEntry->name.c_str(), bitmask);
 134                                 }
 135                                 else
 136                                         ConfEntry->stats_misses++;
 137                         }
 138                         else
 139                                 ConfEntry->stats_misses++;
 140                 }
 141         }
 142
 143         virtual void OnError(ResolverError e, const std::string &errormessage)
 144         {
 145         }
 146
 147         virtual ~DNSBLResolver()
 148         {
 149         }
 150 };
 151
 152 class ModuleDNSBL : public Module
 153 {
 154  private:
 155         std::vector<DNSBLConfEntry *> DNSBLConfEntries;
 156
 157         /*
 158          *      Convert a string to EnumBanaction
 159          */
 160         DNSBLConfEntry::EnumBanaction str2banaction(const std::string &action)
 161         {
 162                 if(action.compare("KILL")==0)
 163                         return DNSBLConfEntry::I_KILL;
 164                 if(action.compare("KLINE")==0)
 165                         return DNSBLConfEntry::I_KLINE;
 166                 if(action.compare("ZLINE")==0)
 167                         return DNSBLConfEntry::I_ZLINE;
 168                 if(action.compare("GLINE")==0)
 169                         return DNSBLConfEntry::I_GLINE;
 170
 171                 return DNSBLConfEntry::I_UNKNOWN;
 172         }
 173  public:
 174         ModuleDNSBL(InspIRCd *Me) : Module(Me)
 175         {
 176                 ReadConf();
 177         }
 178
 179         virtual ~ModuleDNSBL()
 180         {
 181                 ClearEntries();
 182         }
 183
 184         virtual Version GetVersion()
 185         {
 186                 return Version(2, 0, 0, 1, VF_VENDOR, API_VERSION);
 187         }
 188
 189         void Implements(char* List)
 190         {
 191                 List[I_OnRehash] = List[I_OnUserRegister] = List[I_OnStats] = 1;
 192         }
 193
 194         /** Clear entries and free the mem it was using
 195          */
 196         void ClearEntries()
 197         {
 198                 std::vector<DNSBLConfEntry *>::iterator i;
 199                 for (std::vector<DNSBLConfEntry *>::iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); i++)
 200                         delete *i;
 201                 DNSBLConfEntries.clear();
 202         }
 203
 204         /** Fill our conf vector with data
 205          */
 206         virtual void ReadConf()
 207         {
 208                 ConfigReader *MyConf = new ConfigReader(ServerInstance);
 209                 ClearEntries();
 210
 211                 for (int i=0; i< MyConf->Enumerate("dnsbl"); i++)
 212                 {
 213                         DNSBLConfEntry *e = new DNSBLConfEntry();
 214
 215                         e->name = MyConf->ReadValue("dnsbl", "name", i);
 216                         e->reason = MyConf->ReadValue("dnsbl", "reason", i);
 217                         e->domain = MyConf->ReadValue("dnsbl", "domain", i);
 218                         e->banaction = str2banaction(MyConf->ReadValue("dnsbl", "action", i));
 219                         e->duration = ServerInstance->Duration(MyConf->ReadValue("dnsbl", "duration", i).c_str());
 220                         e->bitmask = MyConf->ReadInteger("dnsbl", "bitmask", i, false);
 221
 222                         /* yeah, logic here is a little messy */
 223                         if (e->bitmask <= 0)
 224                         {
 225                                 ServerInstance->WriteOpers("*** DNSBL(#%d): invalid bitmask",i);
 226                         }
 227                         else if (e->name == "")
 228                         {
 229                                 ServerInstance->WriteOpers("*** DNSBL(#%d): Invalid name",i);
 230                         }
 231                         else if (e->domain == "")
 232                         {
 233                                 ServerInstance->WriteOpers("*** DNSBL(#%d): Invalid domain",i);
 234                         }
 235                         else if (e->banaction == DNSBLConfEntry::I_UNKNOWN)
 236                         {
 237                                 ServerInstance->WriteOpers("*** DNSBL(#%d): Invalid banaction", i);
 238                         }
 239                         else
 240                         {
 241                                 if (e->reason == "")
 242                                 {
 243                                         ServerInstance->WriteOpers("*** DNSBL(#%d): empty reason, using defaults",i);
 244                                         e->reason = "Your IP has been blacklisted.";
 245                                 }
 246
 247                                 /* add it, all is ok */
 248                                 DNSBLConfEntries.push_back(e);
 249                                 continue;
 250                         }
 251
 252                         /* delete and drop it, error somewhere */
 253                         delete e;
 254                 }
 255
 256                 delete MyConf;
 257         }
 258
 259         virtual void OnRehash(userrec* user, const std::string &parameter)
 260         {
 261                 ReadConf();
 262         }
 263
 264         virtual int OnUserRegister(userrec* user)
 265         {
 266                 /* only do lookups on local users */
 267                 if (IS_LOCAL(user))
 268                 {
 269                         /* following code taken from bopm, reverses an IP address. */
 270                         struct in_addr in;
 271                         unsigned char a, b, c, d;
 272                         char reversedipbuf[128];
 273                         std::string reversedip;
 274                         bool success = false;
 275
 276                         if (!inet_aton(user->GetIPString(), &in))
 277                         {
 278 #ifdef IPV6
 279                                 /* We could have an ipv6 address here */
 280                                 std::string x = user->GetIPString();
 281                                 /* Is it a 4in6 address? (Compensate for this kernel kludge that people love) */
 282                                 if (x.find("0::ffff:") == 0)
 283                                 {
 284                                         x.erase(x.begin(), x.begin() + 8);
 285                                         if (inet_aton(x.c_str(), &in))
 286                                                 success = true;
 287                                 }
 288 #endif
 289                         }
 290                         else
 291                         {
 292                                 success = true;
 293                         }
 294
 295                         if (!success)
 296                                 return 0;
 297
 298                         d = (unsigned char) (in.s_addr >> 24) & 0xFF;
 299                         c = (unsigned char) (in.s_addr >> 16) & 0xFF;
 300                         b = (unsigned char) (in.s_addr >> 8) & 0xFF;
 301                         a = (unsigned char) in.s_addr & 0xFF;
 302
 303                         snprintf(reversedipbuf, 128, "%d.%d.%d.%d", d, c, b, a);
 304                         reversedip = std::string(reversedipbuf);
 305
 306                         // For each DNSBL, we will run through this lookup
 307                         for (std::vector<DNSBLConfEntry *>::iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); i++)
 308                         {
 309                                 // Fill hostname with a dnsbl style host (d.c.b.a.domain.tld)
 310                                 std::string hostname = reversedip + "." + (*i)->domain;
 311
 312                                 /* now we'd need to fire off lookups for `hostname'. */
 313                                 bool cached;
 314                                 DNSBLResolver *r = new DNSBLResolver(this, ServerInstance, hostname, user, user->GetFd(), *i, cached);
 315                                 ServerInstance->AddResolver(r, cached);
 316                         }
 317                 }
 318
 319                 /* don't do anything with this hot potato */
 320                 return 0;
 321         }
 322
 323         virtual int OnStats(char symbol, userrec* user, string_list &results)
 324         {
 325                 if (symbol != 'd')
 326                         return 0;
 327
 328                 unsigned long total_hits = 0, total_misses = 0;
 329
 330                 for (std::vector<DNSBLConfEntry*>::iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); i++)
 331                 {
 332                         total_hits += (*i)->stats_hits;
 333                         total_misses += (*i)->stats_misses;
 334
 335                         results.push_back(std::string(ServerInstance->Config->ServerName) + " 304 " + user->nick + " :DNSBLSTATS DNSbl \"" + (*i)->name + "\" had " +
 336                                         ConvToStr((*i)->stats_hits) + " hits and " + ConvToStr((*i)->stats_misses) + " misses");
 337                 }
 338
 339                 results.push_back(std::string(ServerInstance->Config->ServerName) + " 304 " + user->nick + " :DNSBLSTATS Total hits: " + ConvToStr(total_hits));
 340                 results.push_back(std::string(ServerInstance->Config->ServerName) + " 304 " + user->nick + " :DNSBLSTATS Total misses: " + ConvToStr(total_misses));
 341
 342                 return 0;
 343         }
 344 };
 345
 346 // stuff down here is the module-factory stuff.
 347
 348 class ModuleDNSBLFactory : public ModuleFactory
 349 {
 350  public:
 351         ModuleDNSBLFactory()
 352         {
 353         }
 354
 355         ~ModuleDNSBLFactory()
 356         {
 357         }
 358
 359         virtual Module *CreateModule(InspIRCd *Me)
 360         {
 361                 return new ModuleDNSBL(Me);
 362         }
 363
 364 };
 365
 366
 367 extern "C" DllExport void * init_module( void )
 368 {
 369         return new ModuleDNSBLFactory;
 370 }