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 #include "modules/dns.h"
  27
  28 /* Class holding data for a single entry */
  29 class DNSBLConfEntry : public refcountbase
  30 {
  31         public:
  32                 enum EnumBanaction { I_UNKNOWN, I_KILL, I_ZLINE, I_KLINE, I_GLINE, I_MARK };
  33                 enum EnumType { A_RECORD, A_BITMASK };
  34                 std::string name, ident, host, domain, reason;
  35                 EnumBanaction banaction;
  36                 EnumType type;
  37                 long duration;
  38                 int bitmask;
  39                 unsigned char records[256];
  40                 unsigned long stats_hits, stats_misses;
  41                 DNSBLConfEntry(): type(A_BITMASK),duration(86400),bitmask(0),stats_hits(0), stats_misses(0) {}
  42 };
  43
  44
  45 /** Resolver for CGI:IRC hostnames encoded in ident/GECOS
  46  */
  47 class DNSBLResolver : public DNS::Request
  48 {
  49         std::string theiruid;
  50         LocalStringExt& nameExt;
  51         LocalIntExt& countExt;
  52         reference<DNSBLConfEntry> ConfEntry;
  53
  54  public:
  55
  56         DNSBLResolver(DNS::Manager *mgr, Module *me, LocalStringExt& match, LocalIntExt& ctr, const std::string &hostname, LocalUser* u, reference<DNSBLConfEntry> conf)
  57                 : DNS::Request(mgr, me, hostname, DNS::QUERY_A, true), theiruid(u->uuid), nameExt(match), countExt(ctr), ConfEntry(conf)
  58         {
  59         }
  60
  61         /* Note: This may be called multiple times for multiple A record results */
  62         void OnLookupComplete(const DNS::Query *r) CXX11_OVERRIDE
  63         {
  64                 /* Check the user still exists */
  65                 LocalUser* them = (LocalUser*)ServerInstance->FindUUID(theiruid);
  66                 if (!them)
  67                         return;
  68
  69                 const DNS::ResourceRecord &ans_record = r->answers[0];
  70
  71                 int i = countExt.get(them);
  72                 if (i)
  73                         countExt.set(them, i - 1);
  74
  75                 // Now we calculate the bitmask: 256*(256*(256*a+b)+c)+d
  76
  77                 unsigned int bitmask = 0, record = 0;
  78                 bool match = false;
  79                 in_addr resultip;
  80
  81                 inet_aton(ans_record.rdata.c_str(), &resultip);
  82
  83                 switch (ConfEntry->type)
  84                 {
  85                         case DNSBLConfEntry::A_BITMASK:
  86                                 bitmask = resultip.s_addr >> 24; /* Last octet (network byte order) */
  87                                 bitmask &= ConfEntry->bitmask;
  88                                 match = (bitmask != 0);
  89                         break;
  90                         case DNSBLConfEntry::A_RECORD:
  91                                 record = resultip.s_addr >> 24; /* Last octet */
  92                                 match = (ConfEntry->records[record] == 1);
  93                         break;
  94                 }
  95
  96                 if (match)
  97                 {
  98                         std::string reason = ConfEntry->reason;
  99                         std::string::size_type x = reason.find("%ip%");
 100                         while (x != std::string::npos)
 101                         {
 102                                 reason.erase(x, 4);
 103                                 reason.insert(x, them->GetIPString());
 104                                 x = reason.find("%ip%");
 105                         }
 106
 107                         ConfEntry->stats_hits++;
 108
 109                         switch (ConfEntry->banaction)
 110                         {
 111                                 case DNSBLConfEntry::I_KILL:
 112                                 {
 113                                         ServerInstance->Users->QuitUser(them, "Killed (" + reason + ")");
 114                                         break;
 115                                 }
 116                                 case DNSBLConfEntry::I_MARK:
 117                                 {
 118                                         if (!ConfEntry->ident.empty())
 119                                         {
 120                                                 them->WriteNumeric(304, ":Your ident has been set to " + ConfEntry->ident + " because you matched " + reason);
 121                                                 them->ChangeIdent(ConfEntry->ident);
 122                                         }
 123
 124                                         if (!ConfEntry->host.empty())
 125                                         {
 126                                                 them->WriteNumeric(304, ":Your host has been set to " + ConfEntry->host + " because you matched " + reason);
 127                                                 them->ChangeDisplayedHost(ConfEntry->host);
 128                                         }
 129
 130                                         nameExt.set(them, ConfEntry->name);
 131                                         break;
 132                                 }
 133                                 case DNSBLConfEntry::I_KLINE:
 134                                 {
 135                                         KLine* kl = new KLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(),
 136                                                         "*", them->GetIPString());
 137                                         if (ServerInstance->XLines->AddLine(kl,NULL))
 138                                         {
 139                                                 std::string timestr = InspIRCd::TimeString(kl->expiry);
 140                                                 ServerInstance->SNO->WriteGlobalSno('x',"K:line added due to DNSBL match on *@%s to expire on %s: %s",
 141                                                         them->GetIPString().c_str(), timestr.c_str(), reason.c_str());
 142                                                 ServerInstance->XLines->ApplyLines();
 143                                         }
 144                                         else
 145                                         {
 146                                                 delete kl;
 147                                                 return;
 148                                         }
 149                                         break;
 150                                 }
 151                                 case DNSBLConfEntry::I_GLINE:
 152                                 {
 153                                         GLine* gl = new GLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(),
 154                                                         "*", them->GetIPString());
 155                                         if (ServerInstance->XLines->AddLine(gl,NULL))
 156                                         {
 157                                                 std::string timestr = InspIRCd::TimeString(gl->expiry);
 158                                                 ServerInstance->SNO->WriteGlobalSno('x',"G:line added due to DNSBL match on *@%s to expire on %s: %s",
 159                                                         them->GetIPString().c_str(), timestr.c_str(), reason.c_str());
 160                                                 ServerInstance->XLines->ApplyLines();
 161                                         }
 162                                         else
 163                                         {
 164                                                 delete gl;
 165                                                 return;
 166                                         }
 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 = InspIRCd::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().c_str(), timestr.c_str(), reason.c_str());
 178                                                 ServerInstance->XLines->ApplyLines();
 179                                         }
 180                                         else
 181                                         {
 182                                                 delete zl;
 183                                                 return;
 184                                         }
 185                                         break;
 186                                 }
 187                                 case DNSBLConfEntry::I_UNKNOWN:
 188                                 default:
 189                                         break;
 190                         }
 191
 192                         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);
 193                 }
 194                 else
 195                         ConfEntry->stats_misses++;
 196         }
 197
 198         void OnError(const DNS::Query *q) CXX11_OVERRIDE
 199         {
 200                 LocalUser* them = (LocalUser*)ServerInstance->FindUUID(theiruid);
 201                 if (!them)
 202                         return;
 203
 204                 int i = countExt.get(them);
 205                 if (i)
 206                         countExt.set(them, i - 1);
 207
 208                 if (q->error == DNS::ERROR_NO_RECORDS || q->error == DNS::ERROR_DOMAIN_NOT_FOUND)
 209                         ConfEntry->stats_misses++;
 210         }
 211 };
 212
 213 class ModuleDNSBL : public Module
 214 {
 215         std::vector<reference<DNSBLConfEntry> > DNSBLConfEntries;
 216         dynamic_reference<DNS::Manager> DNS;
 217         LocalStringExt nameExt;
 218         LocalIntExt countExt;
 219
 220         /*
 221          *      Convert a string to EnumBanaction
 222          */
 223         DNSBLConfEntry::EnumBanaction str2banaction(const std::string &action)
 224         {
 225                 if(action.compare("KILL")==0)
 226                         return DNSBLConfEntry::I_KILL;
 227                 if(action.compare("KLINE")==0)
 228                         return DNSBLConfEntry::I_KLINE;
 229                 if(action.compare("ZLINE")==0)
 230                         return DNSBLConfEntry::I_ZLINE;
 231                 if(action.compare("GLINE")==0)
 232                         return DNSBLConfEntry::I_GLINE;
 233                 if(action.compare("MARK")==0)
 234                         return DNSBLConfEntry::I_MARK;
 235
 236                 return DNSBLConfEntry::I_UNKNOWN;
 237         }
 238  public:
 239         ModuleDNSBL() : DNS(this, "DNS"), nameExt("dnsbl_match", this), countExt("dnsbl_pending", this) { }
 240
 241         Version GetVersion() CXX11_OVERRIDE
 242         {
 243                 return Version("Provides handling of DNS blacklists", VF_VENDOR);
 244         }
 245
 246         /** Fill our conf vector with data
 247          */
 248         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 249         {
 250                 DNSBLConfEntries.clear();
 251
 252                 ConfigTagList dnsbls = ServerInstance->Config->ConfTags("dnsbl");
 253                 for(ConfigIter i = dnsbls.first; i != dnsbls.second; ++i)
 254                 {
 255                         ConfigTag* tag = i->second;
 256                         reference<DNSBLConfEntry> e = new DNSBLConfEntry();
 257
 258                         e->name = tag->getString("name");
 259                         e->ident = tag->getString("ident");
 260                         e->host = tag->getString("host");
 261                         e->reason = tag->getString("reason");
 262                         e->domain = tag->getString("domain");
 263
 264                         if (tag->getString("type") == "bitmask")
 265                         {
 266                                 e->type = DNSBLConfEntry::A_BITMASK;
 267                                 e->bitmask = tag->getInt("bitmask");
 268                         }
 269                         else
 270                         {
 271                                 memset(e->records, 0, sizeof(e->records));
 272                                 e->type = DNSBLConfEntry::A_RECORD;
 273                                 irc::portparser portrange(tag->getString("records"), false);
 274                                 long item = -1;
 275                                 while ((item = portrange.GetToken()))
 276                                         e->records[item] = 1;
 277                         }
 278
 279                         e->banaction = str2banaction(tag->getString("action"));
 280                         e->duration = tag->getDuration("duration", 60, 1);
 281
 282                         /* Use portparser for record replies */
 283
 284                         /* yeah, logic here is a little messy */
 285                         if ((e->bitmask <= 0) && (DNSBLConfEntry::A_BITMASK == e->type))
 286                         {
 287                                 std::string location = tag->getTagLocation();
 288                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): invalid bitmask", location.c_str());
 289                         }
 290                         else if (e->name.empty())
 291                         {
 292                                 std::string location = tag->getTagLocation();
 293                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid name", location.c_str());
 294                         }
 295                         else if (e->domain.empty())
 296                         {
 297                                 std::string location = tag->getTagLocation();
 298                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid domain", location.c_str());
 299                         }
 300                         else if (e->banaction == DNSBLConfEntry::I_UNKNOWN)
 301                         {
 302                                 std::string location = tag->getTagLocation();
 303                                 ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid banaction", location.c_str());
 304                         }
 305                         else
 306                         {
 307                                 if (e->reason.empty())
 308                                 {
 309                                         std::string location = tag->getTagLocation();
 310                                         ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): empty reason, using defaults", location.c_str());
 311                                         e->reason = "Your IP has been blacklisted.";
 312                                 }
 313
 314                                 /* add it, all is ok */
 315                                 DNSBLConfEntries.push_back(e);
 316                         }
 317                 }
 318         }
 319
 320         void OnSetUserIP(LocalUser* user) CXX11_OVERRIDE
 321         {
 322                 if ((user->exempt) || (user->client_sa.sa.sa_family != AF_INET) || !DNS)
 323                         return;
 324
 325                 if (user->MyClass)
 326                 {
 327                         if (!user->MyClass->config->getBool("usednsbl", true))
 328                                 return;
 329                 }
 330                 else
 331                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "User has no connect class in OnSetUserIP");
 332
 333                 unsigned int a, b, c, d;
 334                 d = (unsigned int) (user->client_sa.in4.sin_addr.s_addr >> 24) & 0xFF;
 335                 c = (unsigned int) (user->client_sa.in4.sin_addr.s_addr >> 16) & 0xFF;
 336                 b = (unsigned int) (user->client_sa.in4.sin_addr.s_addr >> 8) & 0xFF;
 337                 a = (unsigned int) user->client_sa.in4.sin_addr.s_addr & 0xFF;
 338
 339                 const std::string reversedip = ConvToStr(d) + "." + ConvToStr(c) + "." + ConvToStr(b) + "." + ConvToStr(a);
 340
 341                 countExt.set(user, DNSBLConfEntries.size());
 342
 343                 // For each DNSBL, we will run through this lookup
 344                 for (unsigned i = 0; i < DNSBLConfEntries.size(); ++i)
 345                 {
 346                         // Fill hostname with a dnsbl style host (d.c.b.a.domain.tld)
 347                         std::string hostname = reversedip + "." + DNSBLConfEntries[i]->domain;
 348
 349                         /* now we'd need to fire off lookups for `hostname'. */
 350                         DNSBLResolver *r = new DNSBLResolver(*this->DNS, this, nameExt, countExt, hostname, user, DNSBLConfEntries[i]);
 351                         try
 352                         {
 353                                 this->DNS->Process(r);
 354                         }
 355                         catch (DNS::Exception &ex)
 356                         {
 357                                 delete r;
 358                                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, ex.GetReason());
 359                         }
 360
 361                         if (user->quitting)
 362                                 break;
 363                 }
 364         }
 365
 366         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE
 367         {
 368                 std::string dnsbl;
 369                 if (!myclass->config->readString("dnsbl", dnsbl))
 370                         return MOD_RES_PASSTHRU;
 371                 std::string* match = nameExt.get(user);
 372                 std::string myname = match ? *match : "";
 373                 if (dnsbl == myname)
 374                         return MOD_RES_PASSTHRU;
 375                 return MOD_RES_DENY;
 376         }
 377
 378         ModResult OnCheckReady(LocalUser *user) CXX11_OVERRIDE
 379         {
 380                 if (countExt.get(user))
 381                         return MOD_RES_DENY;
 382                 return MOD_RES_PASSTHRU;
 383         }
 384
 385         ModResult OnStats(char symbol, User* user, string_list &results) CXX11_OVERRIDE
 386         {
 387                 if (symbol != 'd')
 388                         return MOD_RES_PASSTHRU;
 389
 390                 unsigned long total_hits = 0, total_misses = 0;
 391
 392                 for (std::vector<reference<DNSBLConfEntry> >::const_iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); ++i)
 393                 {
 394                         total_hits += (*i)->stats_hits;
 395                         total_misses += (*i)->stats_misses;
 396
 397                         results.push_back(ServerInstance->Config->ServerName + " 304 " + user->nick + " :DNSBLSTATS DNSbl \"" + (*i)->name + "\" had " +
 398                                         ConvToStr((*i)->stats_hits) + " hits and " + ConvToStr((*i)->stats_misses) + " misses");
 399                 }
 400
 401                 results.push_back(ServerInstance->Config->ServerName + " 304 " + user->nick + " :DNSBLSTATS Total hits: " + ConvToStr(total_hits));
 402                 results.push_back(ServerInstance->Config->ServerName + " 304 " + user->nick + " :DNSBLSTATS Total misses: " + ConvToStr(total_misses));
 403
 404                 return MOD_RES_PASSTHRU;
 405         }
 406 };
 407
 408 MODULE_INIT(ModuleDNSBL)