+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ * Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
+ * Copyright (C) 2006-2008 Robin Burchell <robin+git@viroteck.net>
+ * Copyright (C) 2007 Craig Edwards <craigedwards@brainbox.cc>
+ * Copyright (C) 2006-2007 Dennis Friis <peavey@inspircd.org>
+ * Copyright (C) 2007 John Brooks <john.brooks@dereferenced.net>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+
+#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<DNSBLConfEntry> ConfEntry;
+
+ public:
+
+ DNSBLResolver(Module *me, LocalStringExt& match, LocalIntExt& ctr, const std::string &hostname, LocalUser* u, reference<DNSBLConfEntry> 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);
+ // Now we calculate the bitmask: 256*(256*(256*a+b)+c)+d
+ if(result.length())
+ {
+ 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:
+ 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;
+ 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;
+ 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;
+ 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() ? "<unknown>" : "", them->GetFullRealHost().c_str(), ConfEntry->domain.c_str(), (ConfEntry->type==DNSBLConfEntry::A_BITMASK) ? bitmask : record);
+ }
+ else
+ ConfEntry->stats_misses++;
+ }
+ else
+ 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<reference<DNSBLConfEntry> > 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<DNSBLConfEntry> 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<reference<DNSBLConfEntry> >::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)