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/*
* InspIRCd -- Internet Relay Chat Daemon
*
* Copyright (C) 2017, 2019 Sadie Powell <sadie@witchery.services>
* Copyright (C) 2014-2015 Attila Molnar <attilamolnar@hush.com>
* Copyright (C) 2013, 2015-2016 Adam <Adam@anope.org>
*
* 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/>.
*/
#pragma once
namespace DNS
{
/** Valid query types
*/
enum QueryType
{
/* Nothing */
QUERY_NONE,
/* A simple A lookup */
QUERY_A = 1,
/* A CNAME lookup */
QUERY_CNAME = 5,
/* Reverse DNS lookup */
QUERY_PTR = 12,
/* TXT */
QUERY_TXT = 16,
/* IPv6 AAAA lookup */
QUERY_AAAA = 28
};
/** Flags that can be AND'd into DNSPacket::flags to receive certain values
*/
enum
{
QUERYFLAGS_QR = 0x8000,
QUERYFLAGS_OPCODE = 0x7800,
QUERYFLAGS_AA = 0x400,
QUERYFLAGS_TC = 0x200,
QUERYFLAGS_RD = 0x100,
QUERYFLAGS_RA = 0x80,
QUERYFLAGS_Z = 0x70,
QUERYFLAGS_RCODE = 0xF
};
enum Error
{
ERROR_NONE,
ERROR_DISABLED,
ERROR_UNKNOWN,
ERROR_UNLOADED,
ERROR_TIMEDOUT,
ERROR_MALFORMED,
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
};
typedef uint16_t RequestId;
const int PORT = 53;
class Exception : public ModuleException
{
public:
Exception(const std::string& message) : ModuleException(message) { }
};
struct Question
{
std::string name;
QueryType type;
Question() : type(QUERY_NONE) { }
Question(const std::string& n, QueryType t) : name(n), type(t) { }
bool operator==(const Question& other) const { return ((name == other.name) && (type == other.type)); }
bool operator!=(const Question& other) const { return (!(*this == other)); }
struct hash
{
size_t operator()(const Question& question) const
{
return irc::insensitive()(question.name);
}
};
};
struct ResourceRecord : Question
{
unsigned int ttl;
std::string rdata;
time_t created;
ResourceRecord(const std::string& n, QueryType t) : Question(n, t), ttl(0), created(ServerInstance->Time()) { }
ResourceRecord(const Question& question) : Question(question), ttl(0), created(ServerInstance->Time()) { }
};
struct Query
{
Question question;
std::vector<ResourceRecord> answers;
Error error;
bool cached;
Query() : error(ERROR_NONE), cached(false) { }
Query(const Question& q) : question(q), error(ERROR_NONE), cached(false) { }
const ResourceRecord* FindAnswerOfType(QueryType qtype) const
{
for (std::vector<DNS::ResourceRecord>::const_iterator i = answers.begin(); i != answers.end(); ++i)
{
const DNS::ResourceRecord& rr = *i;
if (rr.type == qtype)
return &rr;
}
return NULL;
}
};
class ReplySocket;
class Request;
/** DNS manager
*/
class Manager : public DataProvider
{
public:
Manager(Module* mod) : DataProvider(mod, "DNS") { }
virtual void Process(Request* req) = 0;
virtual void RemoveRequest(Request* req) = 0;
virtual std::string GetErrorStr(Error) = 0;
virtual std::string GetTypeStr(QueryType) = 0;
};
/** A DNS query.
*/
class Request : public Timer
{
protected:
Manager* const manager;
public:
Question question;
/* Use result cache if available */
bool use_cache;
/* Request id */
RequestId id;
/* Creator of this request */
Module* const creator;
Request(Manager* mgr, Module* mod, const std::string& addr, QueryType qt, bool usecache = true)
: Timer(ServerInstance->Config->ConfValue("dns")->getDuration("timeout", 5, 1))
, manager(mgr)
, question(addr, qt)
, use_cache(usecache)
, id(0)
, creator(mod)
{
}
virtual ~Request()
{
manager->RemoveRequest(this);
}
/** Called when this request succeeds
* @param r The query sent back from the nameserver
*/
virtual void OnLookupComplete(const Query* req) = 0;
/** 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* req) { }
/** Used to time out the query, calls OnError and asks the TimerManager
* to delete this request
*/
bool Tick(time_t now) CXX11_OVERRIDE
{
Query rr(this->question);
rr.error = ERROR_TIMEDOUT;
this->OnError(&rr);
delete this;
return false;
}
};
} // namespace DNS
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