/*
* 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"
#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<DNSBLConfEntry> ConfEntry;
public:
DNSBLResolver(DNS::Manager *mgr, Module *me, LocalStringExt& match, LocalIntExt& ctr, const std::string &hostname, LocalUser* u, reference<DNSBLConfEntry> 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))
{
ServerInstance->SNO->WriteGlobalSno('x', "K-line added due to DNSBL match on *@%s to expire in %s (on %s): %s",
them->GetIPString().c_str(), InspIRCd::DurationString(kl->duration).c_str(),
InspIRCd::TimeString(kl->expiry).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))
{
ServerInstance->SNO->WriteGlobalSno('x', "G-line added due to DNSBL match on *@%s to expire in %s (on %s): %s",
them->GetIPString().c_str(), InspIRCd::DurationString(gl->duration).c_str(),
InspIRCd::TimeString(gl->expiry).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))
{
ServerInstance->SNO->WriteGlobalSno('x', "Z-line added due to DNSBL match on %s to expire in %s (on %s): %s",
them->GetIPString().c_str(), InspIRCd::DurationString(zl->duration).c_str(),
InspIRCd::TimeString(zl->expiry).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<reference<DNSBLConfEntry> > DNSBLConfList;
class ModuleDNSBL : public Module, public Stats::EventListener
{
DNSBLConfList DNSBLConfEntries;
dynamic_reference<DNS::Manager> 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<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 (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 <dnsbl:bitmask> at " + tag->getTagLocation());
}
else if (e->name.empty())
{
throw ModuleException("Empty <dnsbl:name> at " + tag->getTagLocation());
}
else if (e->domain.empty())
{
throw ModuleException("Empty <dnsbl:domain> at " + tag->getTagLocation());
}
else if (e->banaction == DNSBLConfEntry::I_UNKNOWN)
{
throw ModuleException("Unknown <dnsbl:action> 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<reference<DNSBLConfEntry> >::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)
