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