/* * InspIRCd -- Internet Relay Chat Daemon * * Copyright (C) 2009-2010 Daniel De Graaf * Copyright (C) 2006-2008 Robin Burchell * Copyright (C) 2007 Craig Edwards * Copyright (C) 2006-2007 Dennis Friis * Copyright (C) 2007 John Brooks * * This file is part of InspIRCd. InspIRCd is free software: you can * redistribute it and/or modify it under the terms of the GNU General Public * License as published by the Free Software Foundation, version 2. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #include "inspircd.h" #include "xline.h" #include "modules/dns.h" #include "modules/stats.h" /* Class holding data for a single entry */ class DNSBLConfEntry : public refcountbase { public: enum EnumBanaction { I_UNKNOWN, I_KILL, I_ZLINE, I_KLINE, I_GLINE, I_MARK }; enum EnumType { A_RECORD, A_BITMASK }; std::string name, ident, host, domain, reason; EnumBanaction banaction; EnumType type; unsigned long duration; unsigned int bitmask; unsigned char records[256]; unsigned long stats_hits, stats_misses; DNSBLConfEntry(): type(A_BITMASK),duration(86400),bitmask(0),stats_hits(0), stats_misses(0) {} }; /** Resolver for CGI:IRC hostnames encoded in ident/real name */ class DNSBLResolver : public DNS::Request { std::string theiruid; LocalStringExt& nameExt; LocalIntExt& countExt; reference ConfEntry; public: DNSBLResolver(DNS::Manager *mgr, Module *me, LocalStringExt& match, LocalIntExt& ctr, const std::string &hostname, LocalUser* u, reference conf) : DNS::Request(mgr, me, hostname, DNS::QUERY_A, true), theiruid(u->uuid), nameExt(match), countExt(ctr), ConfEntry(conf) { } /* Note: This may be called multiple times for multiple A record results */ void OnLookupComplete(const DNS::Query *r) CXX11_OVERRIDE { /* Check the user still exists */ LocalUser* them = (LocalUser*)ServerInstance->FindUUID(theiruid); if (!them) return; const DNS::ResourceRecord* const ans_record = r->FindAnswerOfType(DNS::QUERY_A); if (!ans_record) return; // All replies should be in 127.0.0.0/8 if (ans_record->rdata.compare(0, 4, "127.") != 0) { ServerInstance->SNO->WriteGlobalSno('d', "DNSBL: %s returned address outside of acceptable subnet 127.0.0.0/8: %s", ConfEntry->domain.c_str(), ans_record->rdata.c_str()); ConfEntry->stats_misses++; return; } int i = countExt.get(them); if (i) countExt.set(them, i - 1); // Now we calculate the bitmask: 256*(256*(256*a+b)+c)+d unsigned int bitmask = 0, record = 0; bool match = false; in_addr resultip; inet_pton(AF_INET, ans_record->rdata.c_str(), &resultip); switch (ConfEntry->type) { case DNSBLConfEntry::A_BITMASK: bitmask = resultip.s_addr >> 24; /* Last octet (network byte order) */ bitmask &= ConfEntry->bitmask; match = (bitmask != 0); break; case DNSBLConfEntry::A_RECORD: record = resultip.s_addr >> 24; /* Last octet */ match = (ConfEntry->records[record] == 1); break; } if (match) { std::string reason = ConfEntry->reason; std::string::size_type x = reason.find("%ip%"); while (x != std::string::npos) { reason.erase(x, 4); reason.insert(x, them->GetIPString()); x = reason.find("%ip%"); } ConfEntry->stats_hits++; switch (ConfEntry->banaction) { case DNSBLConfEntry::I_KILL: { ServerInstance->Users->QuitUser(them, "Killed (" + reason + ")"); break; } case DNSBLConfEntry::I_MARK: { if (!ConfEntry->ident.empty()) { them->WriteNotice("Your ident has been set to " + ConfEntry->ident + " because you matched " + reason); them->ChangeIdent(ConfEntry->ident); } if (!ConfEntry->host.empty()) { them->WriteNotice("Your host has been set to " + ConfEntry->host + " because you matched " + reason); them->ChangeDisplayedHost(ConfEntry->host); } nameExt.set(them, ConfEntry->name); break; } case DNSBLConfEntry::I_KLINE: { KLine* kl = new KLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(), "*", them->GetIPString()); if (ServerInstance->XLines->AddLine(kl,NULL)) { std::string timestr = InspIRCd::TimeString(kl->expiry); ServerInstance->SNO->WriteGlobalSno('x', "K-line added due to DNSBL match on *@%s to expire on %s: %s", them->GetIPString().c_str(), timestr.c_str(), reason.c_str()); ServerInstance->XLines->ApplyLines(); } else { delete kl; return; } break; } case DNSBLConfEntry::I_GLINE: { GLine* gl = new GLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(), "*", them->GetIPString()); if (ServerInstance->XLines->AddLine(gl,NULL)) { std::string timestr = InspIRCd::TimeString(gl->expiry); ServerInstance->SNO->WriteGlobalSno('x', "G-line added due to DNSBL match on *@%s to expire on %s: %s", them->GetIPString().c_str(), timestr.c_str(), reason.c_str()); ServerInstance->XLines->ApplyLines(); } else { delete gl; return; } break; } case DNSBLConfEntry::I_ZLINE: { ZLine* zl = new ZLine(ServerInstance->Time(), ConfEntry->duration, ServerInstance->Config->ServerName.c_str(), reason.c_str(), them->GetIPString()); if (ServerInstance->XLines->AddLine(zl,NULL)) { std::string timestr = InspIRCd::TimeString(zl->expiry); ServerInstance->SNO->WriteGlobalSno('x', "Z-line added due to DNSBL match on %s to expire on %s: %s", them->GetIPString().c_str(), timestr.c_str(), reason.c_str()); ServerInstance->XLines->ApplyLines(); } else { delete zl; return; } break; } case DNSBLConfEntry::I_UNKNOWN: default: break; } ServerInstance->SNO->WriteGlobalSno('d', "Connecting user %s (%s) detected as being on the '%s' DNS blacklist with result %d", them->GetFullRealHost().c_str(), them->GetIPString().c_str(), ConfEntry->name.c_str(), (ConfEntry->type==DNSBLConfEntry::A_BITMASK) ? bitmask : record); } else ConfEntry->stats_misses++; } void OnError(const DNS::Query *q) CXX11_OVERRIDE { LocalUser* them = (LocalUser*)ServerInstance->FindUUID(theiruid); if (!them) return; int i = countExt.get(them); if (i) countExt.set(them, i - 1); if (q->error == DNS::ERROR_NO_RECORDS || q->error == DNS::ERROR_DOMAIN_NOT_FOUND) { ConfEntry->stats_misses++; return; } ServerInstance->SNO->WriteGlobalSno('d', "An error occurred whilst checking whether %s (%s) is on the '%s' DNS blacklist: %s", them->GetFullRealHost().c_str(), them->GetIPString().c_str(), ConfEntry->name.c_str(), this->manager->GetErrorStr(q->error).c_str()); } }; typedef std::vector > DNSBLConfList; class ModuleDNSBL : public Module, public Stats::EventListener { DNSBLConfList DNSBLConfEntries; dynamic_reference DNS; LocalStringExt nameExt; LocalIntExt countExt; /* * Convert a string to EnumBanaction */ DNSBLConfEntry::EnumBanaction str2banaction(const std::string &action) { if(action.compare("KILL")==0) return DNSBLConfEntry::I_KILL; if(action.compare("KLINE")==0) return DNSBLConfEntry::I_KLINE; if(action.compare("ZLINE")==0) return DNSBLConfEntry::I_ZLINE; if(action.compare("GLINE")==0) return DNSBLConfEntry::I_GLINE; if(action.compare("MARK")==0) return DNSBLConfEntry::I_MARK; return DNSBLConfEntry::I_UNKNOWN; } public: ModuleDNSBL() : Stats::EventListener(this) , DNS(this, "DNS") , nameExt("dnsbl_match", ExtensionItem::EXT_USER, this) , countExt("dnsbl_pending", ExtensionItem::EXT_USER, this) { } void init() CXX11_OVERRIDE { ServerInstance->SNO->EnableSnomask('d', "DNSBL"); } Version GetVersion() CXX11_OVERRIDE { return Version("Provides handling of DNS blacklists", VF_VENDOR); } /** Fill our conf vector with data */ void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE { DNSBLConfList newentries; ConfigTagList dnsbls = ServerInstance->Config->ConfTags("dnsbl"); for(ConfigIter i = dnsbls.first; i != dnsbls.second; ++i) { ConfigTag* tag = i->second; reference e = new DNSBLConfEntry(); e->name = tag->getString("name"); e->ident = tag->getString("ident"); e->host = tag->getString("host"); e->reason = tag->getString("reason"); e->domain = tag->getString("domain"); if (stdalgo::string::equalsci(tag->getString("type"), "bitmask")) { e->type = DNSBLConfEntry::A_BITMASK; e->bitmask = tag->getUInt("bitmask", 0, 0, UINT_MAX); } else { memset(e->records, 0, sizeof(e->records)); e->type = DNSBLConfEntry::A_RECORD; irc::portparser portrange(tag->getString("records"), false); long item = -1; while ((item = portrange.GetToken())) e->records[item] = 1; } e->banaction = str2banaction(tag->getString("action")); e->duration = tag->getDuration("duration", 60, 1); /* Use portparser for record replies */ /* yeah, logic here is a little messy */ if ((e->bitmask <= 0) && (DNSBLConfEntry::A_BITMASK == e->type)) { throw ModuleException("Invalid at " + tag->getTagLocation()); } else if (e->name.empty()) { throw ModuleException("Empty at " + tag->getTagLocation()); } else if (e->domain.empty()) { throw ModuleException("Empty at " + tag->getTagLocation()); } else if (e->banaction == DNSBLConfEntry::I_UNKNOWN) { throw ModuleException("Unknown at " + tag->getTagLocation()); } else { if (e->reason.empty()) { std::string location = tag->getTagLocation(); ServerInstance->SNO->WriteGlobalSno('d', "DNSBL(%s): empty reason, using defaults", location.c_str()); e->reason = "Your IP has been blacklisted."; } /* add it, all is ok */ newentries.push_back(e); } } DNSBLConfEntries.swap(newentries); } void OnSetUserIP(LocalUser* user) CXX11_OVERRIDE { if ((user->exempt) || !DNS) return; // Clients can't be in a DNSBL if they aren't connected via IPv4 or IPv6. if (user->client_sa.family() != AF_INET && user->client_sa.family() != AF_INET6) return; if (user->MyClass) { if (!user->MyClass->config->getBool("usednsbl", true)) return; } else ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "User has no connect class in OnSetUserIP"); std::string reversedip; if (user->client_sa.family() == AF_INET) { unsigned int a, b, c, d; d = (unsigned int) (user->client_sa.in4.sin_addr.s_addr >> 24) & 0xFF; c = (unsigned int) (user->client_sa.in4.sin_addr.s_addr >> 16) & 0xFF; b = (unsigned int) (user->client_sa.in4.sin_addr.s_addr >> 8) & 0xFF; a = (unsigned int) user->client_sa.in4.sin_addr.s_addr & 0xFF; reversedip = ConvToStr(d) + "." + ConvToStr(c) + "." + ConvToStr(b) + "." + ConvToStr(a); } else if (user->client_sa.family() == AF_INET6) { const unsigned char* ip = user->client_sa.in6.sin6_addr.s6_addr; std::string buf = BinToHex(ip, 16); for (std::string::const_reverse_iterator it = buf.rbegin(); it != buf.rend(); ++it) { reversedip.push_back(*it); reversedip.push_back('.'); } } else return; ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Reversed IP %s -> %s", user->GetIPString().c_str(), reversedip.c_str()); countExt.set(user, DNSBLConfEntries.size()); // For each DNSBL, we will run through this lookup for (unsigned i = 0; i < DNSBLConfEntries.size(); ++i) { // Fill hostname with a dnsbl style host (d.c.b.a.domain.tld) std::string hostname = reversedip + "." + DNSBLConfEntries[i]->domain; /* now we'd need to fire off lookups for `hostname'. */ DNSBLResolver *r = new DNSBLResolver(*this->DNS, this, nameExt, countExt, hostname, user, DNSBLConfEntries[i]); try { this->DNS->Process(r); } catch (DNS::Exception &ex) { delete r; ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, ex.GetReason()); } if (user->quitting) break; } } ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE { std::string dnsbl; if (!myclass->config->readString("dnsbl", dnsbl)) return MOD_RES_PASSTHRU; std::string* match = nameExt.get(user); if (!match) return MOD_RES_PASSTHRU; if (InspIRCd::Match(*match, dnsbl)) return MOD_RES_PASSTHRU; return MOD_RES_DENY; } ModResult OnCheckReady(LocalUser *user) CXX11_OVERRIDE { if (countExt.get(user)) return MOD_RES_DENY; return MOD_RES_PASSTHRU; } ModResult OnStats(Stats::Context& stats) CXX11_OVERRIDE { if (stats.GetSymbol() != 'd') return MOD_RES_PASSTHRU; unsigned long total_hits = 0, total_misses = 0; for (std::vector >::const_iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); ++i) { total_hits += (*i)->stats_hits; total_misses += (*i)->stats_misses; stats.AddRow(304, "DNSBLSTATS DNSbl \"" + (*i)->name + "\" had " + ConvToStr((*i)->stats_hits) + " hits and " + ConvToStr((*i)->stats_misses) + " misses"); } stats.AddRow(304, "DNSBLSTATS Total hits: " + ConvToStr(total_hits)); stats.AddRow(304, "DNSBLSTATS Total misses: " + ConvToStr(total_misses)); return MOD_RES_PASSTHRU; } }; MODULE_INIT(ModuleDNSBL)