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/*
*
* (C) 2003-2012 Anope Team
* Contact us at team@anope.org
*
* Please read COPYING and README for further details.
*
* Based on the original code of Epona by Lara.
* Based on the original code of Services by Andy Church.
*
*
*/
#ifndef DNS_H
#define DNS_H
#include "sockets.h"
#include "timers.h"
#include "extern.h"
#include "config.h"
/** Valid query types
*/
enum QueryType
{
/* Nothing */
DNS_QUERY_NONE,
/* A simple A lookup */
DNS_QUERY_A = 1,
/* A CNAME lookup */
DNS_QUERY_CNAME = 5,
/* Reverse DNS lookup */
DNS_QUERY_PTR = 12,
/* IPv6 AAAA lookup */
DNS_QUERY_AAAA = 28
};
/** Flags that can be AND'd into DNSPacket::flags to receive certain values
*/
enum
{
DNS_QUERYFLAGS_QR = 0x8000,
DNS_QUERYFLAGS_OPCODE = 0x7800,
DNS_QUERYFLAGS_AA = 0x400,
DBS_QUERYFLAGS_TC = 0x200,
DNS_QUERYFLAGS_RD = 0x100,
DNS_QUERYFLAGS_RA = 0x80,
DNS_QUERYFLAGS_Z = 0x70,
DNS_QUERYFLAGS_RCODE = 0xF
};
enum DNSError
{
DNS_ERROR_NONE,
DNS_ERROR_UNKNOWN,
DNS_ERROR_UNLOADED,
DNS_ERROR_TIMEOUT,
DNS_ERROR_NOT_AN_ANSWER,
DNS_ERROR_NONSTANDARD_QUERY,
DNS_ERROR_FORMAT_ERROR,
DNS_ERROR_SERVER_FAILURE,
DNS_ERROR_DOMAIN_NOT_FOUND,
DNS_ERROR_NOT_IMPLEMENTED,
DNS_ERROR_REFUSED,
DNS_ERROR_NO_RECORDS,
DNS_ERROR_INVALIDTYPE
};
struct CoreExport Question
{
Anope::string name;
QueryType type;
unsigned short qclass;
Question();
Question(const Anope::string &, QueryType, unsigned short = 1);
};
struct CoreExport ResourceRecord : public Question
{
unsigned int ttl;
Anope::string rdata;
time_t created;
ResourceRecord(const Anope::string &, QueryType, unsigned short = 1);
ResourceRecord(const Question &);
};
struct CoreExport DNSQuery
{
std::vector<Question> questions;
std::vector<ResourceRecord> answers, authorities, additional;
DNSError error;
DNSQuery();
DNSQuery(const Question &q);
DNSQuery(const DNSPacket &p);
};
/** The request
*/
class CoreExport DNSRequest : public Timer, public Question
{
/* Use result cache if available */
bool use_cache;
public:
/* Request id */
unsigned short id;
/* Creator of this request */
Module *creator;
DNSRequest(const Anope::string &addr, QueryType qt, bool cache = false, Module *c = NULL);
virtual ~DNSRequest();
void Process();
virtual void OnLookupComplete(const DNSQuery *r) = 0;
virtual void OnError(const DNSQuery *r);
void Tick(time_t) anope_override;
};
/** A full packet sent or recieved to/from the nameserver, may contain multiple queries
*/
class DNSPacket : public DNSQuery
{
static const int DNS_POINTER = 0xC0;
static const int DNS_LABEL = 0x3F;
void PackName(unsigned char *output, unsigned short output_size, unsigned short &pos, const Anope::string &name);
Anope::string UnpackName(const unsigned char *input, unsigned short input_size, unsigned short &pos);
Question UnpackQuestion(const unsigned char *input, unsigned short input_size, unsigned short &pos);
ResourceRecord UnpackResourceRecord(const unsigned char *input, unsigned short input_size, unsigned short &poss);
public:
static const int HEADER_LENGTH = 12;
/* Our 16-bit id for this header */
unsigned short id;
/* Flags on the query */
unsigned short flags;
DNSPacket();
void Fill(const unsigned char *input, const unsigned short len);
unsigned short Pack(unsigned char *output, unsigned short output_size);
};
/** DNS manager, manages all requests
*/
class CoreExport DNSManager : public Timer, public Socket
{
typedef std::multimap<Anope::string, ResourceRecord, ci::less> cache_map;
cache_map cache;
sockaddrs addrs;
public:
std::deque<DNSPacket *> packets;
std::map<unsigned short, DNSRequest *> requests;
static const int DNSPort = 53;
DNSManager(const Anope::string &nameserver, int port);
~DNSManager();
bool ProcessRead();
bool ProcessWrite();
/** Add a record to the dns cache
* @param r The record
*/
void AddCache(DNSQuery &r);
/** Check the DNS cache to see if request can be handled by a cached result
* @return true if a cached result was found.
*/
bool CheckCache(DNSRequest *request);
/** Tick this timer, used to clear the DNS cache.
*/
void Tick(time_t now) anope_override;
/** Cleanup all pending DNS queries for a module
* @param mod The module
*/
void Cleanup(Module *mod);
/** Does a BLOCKING DNS query and returns the first IP.
* Only use this if you know what you are doing. Unless you specifically
* need a blocking query use the DNSRequest system
*/
static DNSQuery BlockingQuery(const Anope::string &mask, QueryType qt);
};
extern DNSManager *DNSEngine;
#endif // DNS_H
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