/* * 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" /* $ModDesc: Provides handling of DNS blacklists */ /* 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; long duration; 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) {} ~DNSBLConfEntry() { } }; /** Resolver for CGI:IRC hostnames encoded in ident/GECOS */ class DNSBLResolver : public Resolver { std::string theiruid; LocalStringExt& nameExt; LocalIntExt& countExt; reference ConfEntry; public: DNSBLResolver(Module *me, LocalStringExt& match, LocalIntExt& ctr, const std::string &hostname, LocalUser* u, reference conf, bool &cached) : Resolver(hostname, DNS_QUERY_A, cached, me), theiruid(u->uuid), nameExt(match), countExt(ctr), ConfEntry(conf) { } /* Note: This may be called multiple times for multiple A record results */ virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached) { /* Check the user still exists */ LocalUser* them = (LocalUser*)ServerInstance->FindUUID(theiruid); if (them) { int i = countExt.get(them); if (i) countExt.set(them, i - 1); // All replies should be in 127.0.0.0/8 if (result.compare(0, 4, "127.") == 0) { unsigned int bitmask = 0, record = 0; bool match = false; in_addr resultip; inet_aton(result.c_str(), &resultip); switch (ConfEntry->type) { case DNSBLConfEntry::A_BITMASK: // Now we calculate the bitmask: 256*(256*(256*a+b)+c)+d 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->WriteServ("304 " + them->nick + " :Your ident has been set to " + ConfEntry->ident + " because you matched " + reason); them->ChangeIdent(ConfEntry->ident.c_str()); } if (!ConfEntry->host.empty()) { them->WriteServ("304 " + them->nick + " :Your host has been set to " + ConfEntry->host + " because you matched " + reason); them->ChangeDisplayedHost(ConfEntry->host.c_str()); } 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 = ServerInstance->TimeString(kl->expiry); ServerInstance->SNO->WriteGlobalSno('x',"K:line added due to DNSBL match on *@%s to expire on %s: %s", them->GetIPString(), 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 = ServerInstance->TimeString(gl->expiry); ServerInstance->SNO->WriteGlobalSno('x',"G:line added due to DNSBL match on *@%s to expire on %s: %s", them->GetIPString(), 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 = ServerInstance->TimeString(zl->expiry); ServerInstance->SNO->WriteGlobalSno('x',"Z:line added due to DNSBL match on *@%s to expire on %s: %s", them->GetIPString(), timestr.c_str(), reason.c_str()); ServerInstance->XLines->ApplyLines(); } else { delete zl; return; } break; } case DNSBLConfEntry::I_UNKNOWN: { break; } break; } ServerInstance->SNO->WriteGlobalSno('a', "Connecting user %s%s detected as being on a DNS blacklist (%s) with result %d", them->nick.empty() ? "" : "", them->GetFullRealHost().c_str(), ConfEntry->domain.c_str(), (ConfEntry->type==DNSBLConfEntry::A_BITMASK) ? bitmask : record); } else ConfEntry->stats_misses++; } else { if (!result.empty()) ServerInstance->SNO->WriteGlobalSno('a', "DNSBL: %s returned address outside of acceptable subnet 127.0.0.0/8: %s", ConfEntry->domain.c_str(), result.c_str()); ConfEntry->stats_misses++; } } } virtual void OnError(ResolverError e, const std::string &errormessage) { LocalUser* them = (LocalUser*)ServerInstance->FindUUID(theiruid); if (them) { int i = countExt.get(them); if (i) countExt.set(them, i - 1); } } virtual ~DNSBLResolver() { } }; class ModuleDNSBL : public Module { std::vector > DNSBLConfEntries; 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() : nameExt("dnsbl_match", this), countExt("dnsbl_pending", this) { } void init() { ReadConf(); ServerInstance->Modules->AddService(nameExt); ServerInstance->Modules->AddService(countExt); Implementation eventlist[] = { I_OnRehash, I_OnSetUserIP, I_OnStats, I_OnSetConnectClass, I_OnCheckReady }; ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation)); } Version GetVersion() { return Version("Provides handling of DNS blacklists", VF_VENDOR); } /** Fill our conf vector with data */ void ReadConf() { DNSBLConfEntries.clear(); 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 (tag->getString("type") == "bitmask") { e->type = DNSBLConfEntry::A_BITMASK; e->bitmask = tag->getInt("bitmask"); } 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 = ServerInstance->Duration(tag->getString("duration", "60")); /* Use portparser for record replies */ /* yeah, logic here is a little messy */ if ((e->bitmask <= 0) && (DNSBLConfEntry::A_BITMASK == e->type)) { std::string location = tag->getTagLocation(); ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): invalid bitmask", location.c_str()); } else if (e->name.empty()) { std::string location = tag->getTagLocation(); ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid name", location.c_str()); } else if (e->domain.empty()) { std::string location = tag->getTagLocation(); ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid domain", location.c_str()); } else if (e->banaction == DNSBLConfEntry::I_UNKNOWN) { std::string location = tag->getTagLocation(); ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid banaction", location.c_str()); } else if (e->duration <= 0) { std::string location = tag->getTagLocation(); ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): Invalid duration", location.c_str()); } else { if (e->reason.empty()) { std::string location = tag->getTagLocation(); ServerInstance->SNO->WriteGlobalSno('a', "DNSBL(%s): empty reason, using defaults", location.c_str()); e->reason = "Your IP has been blacklisted."; } /* add it, all is ok */ DNSBLConfEntries.push_back(e); } } } void OnRehash(User* user) { ReadConf(); } void OnSetUserIP(LocalUser* user) { if ((user->exempt) || (user->client_sa.sa.sa_family != AF_INET)) return; if (user->MyClass) { if (!user->MyClass->config->getBool("usednsbl", true)) return; } else ServerInstance->Logs->Log("m_dnsbl", DEBUG, "User has no connect class in OnSetUserIP"); unsigned char a, b, c, d; char reversedipbuf[128]; std::string reversedip; d = (unsigned char) (user->client_sa.in4.sin_addr.s_addr >> 24) & 0xFF; c = (unsigned char) (user->client_sa.in4.sin_addr.s_addr >> 16) & 0xFF; b = (unsigned char) (user->client_sa.in4.sin_addr.s_addr >> 8) & 0xFF; a = (unsigned char) user->client_sa.in4.sin_addr.s_addr & 0xFF; snprintf(reversedipbuf, 128, "%d.%d.%d.%d", d, c, b, a); reversedip = std::string(reversedipbuf); countExt.set(user, DNSBLConfEntries.size()); // For each DNSBL, we will run through this lookup unsigned int i = 0; while (i < DNSBLConfEntries.size()) { // 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'. */ bool cached; DNSBLResolver *r = new DNSBLResolver(this, nameExt, countExt, hostname, user, DNSBLConfEntries[i], cached); ServerInstance->AddResolver(r, cached); if (user->quitting) break; i++; } } ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) { std::string dnsbl; if (!myclass->config->readString("dnsbl", dnsbl)) return MOD_RES_PASSTHRU; std::string* match = nameExt.get(user); std::string myname = match ? *match : ""; if (dnsbl == myname) return MOD_RES_PASSTHRU; return MOD_RES_DENY; } ModResult OnCheckReady(LocalUser *user) { if (countExt.get(user)) return MOD_RES_DENY; return MOD_RES_PASSTHRU; } ModResult OnStats(char symbol, User* user, string_list &results) { if (symbol != '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; results.push_back(ServerInstance->Config->ServerName + " 304 " + user->nick + " :DNSBLSTATS DNSbl \"" + (*i)->name + "\" had " + ConvToStr((*i)->stats_hits) + " hits and " + ConvToStr((*i)->stats_misses) + " misses"); } results.push_back(ServerInstance->Config->ServerName + " 304 " + user->nick + " :DNSBLSTATS Total hits: " + ConvToStr(total_hits)); results.push_back(ServerInstance->Config->ServerName + " 304 " + user->nick + " :DNSBLSTATS Total misses: " + ConvToStr(total_misses)); return MOD_RES_PASSTHRU; } }; MODULE_INIT(ModuleDNSBL)