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/*
* Anope IRC Services
*
* Copyright (C) 2012-2017 Anope Team <team@anope.org>
*
* This file is part of Anope. Anope 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 see <http://www.gnu.org/licenses/>.
*/
#ifndef DNS_H
#define DNS_H
namespace DNS
{
/** Valid query types
*/
enum QueryType
{
/* Nothing */
QUERY_NONE,
/* A simple A lookup */
QUERY_A = 1,
/* An authoritative name server */
QUERY_NS = 2,
/* A CNAME lookup */
QUERY_CNAME = 5,
/* Start of a zone of authority */
QUERY_SOA = 6,
/* Reverse DNS lookup */
QUERY_PTR = 12,
/* IPv6 AAAA lookup */
QUERY_AAAA = 28,
/* Zone transfer */
QUERY_AXFR = 252,
/* A lookup for any record */
QUERY_ANY = 255
};
/** Flags that can be AND'd into DNSPacket::flags to receive certain values
*/
enum
{
QUERYFLAGS_QR = 0x8000,
QUERYFLAGS_OPCODE = 0x7800,
QUERYFLAGS_OPCODE_NOTIFY = 0x2000,
QUERYFLAGS_AA = 0x400,
QUERYFLAGS_TC = 0x200,
QUERYFLAGS_RD = 0x100,
QUERYFLAGS_RA = 0x80,
QUERYFLAGS_Z = 0x70,
QUERYFLAGS_RCODE = 0xF
};
enum Error
{
ERROR_NONE,
ERROR_UNKNOWN,
ERROR_UNLOADED,
ERROR_TIMEDOUT,
ERROR_NOT_AN_ANSWER,
ERROR_NONSTANDARD_QUERY,
ERROR_FORMAT_ERROR,
ERROR_SERVER_FAILURE,
ERROR_DOMAIN_NOT_FOUND,
ERROR_NOT_IMPLEMENTED,
ERROR_REFUSED,
ERROR_NO_RECORDS,
ERROR_INVALIDTYPE
};
struct Question
{
Anope::string name;
QueryType type;
unsigned short qclass;
Question() : type(QUERY_NONE), qclass(0) { }
Question(const Anope::string &n, QueryType t, unsigned short c = 1) : name(n), type(t), qclass(c) { }
inline bool operator==(const Question & other) const { return name == other.name && type == other.type && qclass == other.qclass; }
struct hash
{
size_t operator()(const Question &q) const
{
return Anope::hash_ci()(q.name);
}
};
};
struct ResourceRecord : Question
{
unsigned int ttl;
Anope::string rdata;
time_t created;
ResourceRecord(const Anope::string &n, QueryType t, unsigned short c = 1) : Question(n, t, c), ttl(0), created(Anope::CurTime) { }
ResourceRecord(const Question &q) : Question(q), ttl(0), created(Anope::CurTime) { }
};
struct Query
{
std::vector<Question> questions;
std::vector<ResourceRecord> answers, authorities, additional;
Error error;
Query() : error(ERROR_NONE) { }
Query(const Question &q) : error(ERROR_NONE) { questions.push_back(q); }
};
class ReplySocket;
class Request;
/** DNS manager
*/
class Manager : public Service
{
public:
static constexpr const char *NAME = "dns/manager";
Manager(Module *creator) : Service(creator, NAME) { }
virtual ~Manager() { }
virtual void Process(Request *req) anope_abstract;
virtual void RemoveRequest(Request *req) anope_abstract;
virtual bool HandlePacket(ReplySocket *s, const unsigned char *const data, int len, sockaddrs *from) anope_abstract;
virtual void UpdateSerial() anope_abstract;
virtual void Notify(const Anope::string &zone) anope_abstract;
virtual uint32_t GetSerial() const anope_abstract;
};
/** A DNS query.
*/
class Request : public Timer, public Question
{
Manager *manager;
public:
/* Use result cache if available */
bool use_cache;
/* Request id */
unsigned short id;
/* Creator of this request */
Module *creator;
Request(Manager *mgr, Module *c, const Anope::string &addr, QueryType qt, bool cache = false) : Timer(0), Question(addr, qt), manager(mgr),
use_cache(cache), id(0), creator(c) { }
virtual ~Request()
{
manager->RemoveRequest(this);
}
/** Called when this request succeeds
* @param r The query sent back from the nameserver
*/
virtual void OnLookupComplete(const Query *r) anope_abstract;
/** Called when this request fails or times out.
* @param r The query sent back from the nameserver, check the error code.
*/
virtual void OnError(const Query *r) { }
/** Used to time out the query, xalls OnError and lets the TimerManager
* delete this request.
*/
void Tick(time_t) override
{
Anope::Logger.Debug2("Resolver: timeout for query {0}", this->name);
Query rr(*this);
rr.error = ERROR_TIMEDOUT;
this->OnError(&rr);
}
};
} // namespace DNS
namespace Event
{
struct CoreExport DnsRequest : Events
{
static constexpr const char *NAME = "dnsrequest";
using Events::Events;
/** Called when a DNS request (question) is recieved.
* @param req The dns request
* @param reply The reply that will be sent
*/
virtual void OnDnsRequest(DNS::Query &req, DNS::Query *reply) anope_abstract;
};
}
#endif // DNS_H
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