netsukuku/src/dnslib.h

				 /**************************************
                *     AUTHOR: Federico Tomassini        *
               *     Copyright (C) Federico Tomassini    *
              *     Contact effetom@gmail.com             *
             ***********************************************
             *******          BEGIN 3/2006          ********
*************************************************************************
*                                                                       *
*  This program 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; either version 2 of the License, or    *
*  (at your option) any later version.                                  *
*                                                                       *
*  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.                         *
*                                                                       *
************************************************************************/
#ifndef DNSLIB_H
#define DNSLIB_H

#include <string.h>
#include <stdint.h>
#include <sys/socket.h>
#include <arpa/inet.h>

#define LBL_PTR_MASK		0xC0	/* Network byte order */
#define LBL_PTR_OFF_MASK	0x3f	/* N.b. order */
#define LBL_PTR(c)		((c)&LBL_PTR_MASK)	/* AND whith 0xC000 */

#define MAX_RECURSION_PTR	20

/* PREFIXES FOR PTR QUERY */
#define DNS_INV_PREFIX          ".IN-ADDR.ARPA"
#define DNS_INV_PREFIX6         ".IP6.ARPA"
#define OLD_DNS_INV_PREFIX6     ".IP6.INT"	/* For backward compatibility */

/* DNS QUERY-TYPE: others type will be discarded */

#define T_AAAA  28				/* h->ip IPV6  */
#define T_A     1				/* h->ip IPV4 */
#define T_PTR   12				/* ip->h */
#define T_MX    15				/* h->mx */
/* RCODES */
#define DNS_RCODE_NOERR     0	/* No error */
#define DNS_RCODE_EINTRPRT  1	/* Intepret error */
#define DNS_RCODE_ESRVFAIL  2	/* Server failure */
#define DNS_RCODE_ENSDMN    3	/* No such domain */
#define DNS_RCODE_ENIMPL    4	/* Not implemented */
#define DNS_RCODE_ERFSD     5	/* Refused */

/* INET CLASS */
#define C_IN    1

/* RFC */
#define DNS_MAX_SZ		512
#define DNS_HDR_SZ		12
#define DNS_MAX_LABELS		63
#define DNS_MAX_HNAME_LEN	255
#define DNS_TTL 86400;

#define min(x,y)		((x)<(y))?(x):(y)

typedef struct dns_pkt_hdr {
	uint16_t id;
	uint8_t qr;
	uint8_t opcode;
	uint8_t aa;
	uint8_t tc;
	uint8_t rd;
	uint8_t ra;
	uint8_t z;
	uint8_t rcode;
	uint8_t qdcount;
	uint8_t ancount;
	uint8_t nscount;
	uint8_t arcount;
} dns_pkt_hdr;
#define DNS_PKT_HDR_SZ sizeof(dns_pkt_hdr)

/* DNS_PKT_HDR MACROS */
#define DP_QDCOUNT(dp)  ((dp)->pkt_hdr).qdcount
#define DP_ANCOUNT(dp)  ((dp)->pkt_hdr).ancount
#define DP_NSCOUNT(dp)  ((dp)->pkt_hdr).nscount
#define DP_ARCOUNT(dp)  ((dp)->pkt_hdr).arcount


struct dns_pkt_qst {
	char qname[DNS_MAX_HNAME_LEN];
	uint16_t qtype;
	uint16_t qclass;
	struct dns_pkt_qst *next;
};
typedef struct dns_pkt_qst dns_pkt_qst;
#define DNS_PKT_QST_SZ sizeof(dns_pkt_qst)

struct dns_pkt_a {
	char name[DNS_MAX_HNAME_LEN];
	uint16_t type;
	uint16_t cl;
	uint32_t ttl;
	uint16_t rdlength;
	char rdata[DNS_MAX_HNAME_LEN];
	struct dns_pkt_a *next;
};
typedef struct dns_pkt_a dns_pkt_a;
#define DNS_PKT_A_SZ sizeof(dns_pkt_a)

typedef struct dns_pkt {
	dns_pkt_hdr pkt_hdr;
	dns_pkt_qst *pkt_qst;
	dns_pkt_a *pkt_answ;
	dns_pkt_a *pkt_auth;
	dns_pkt_a *pkt_add;
} dns_pkt;
#define DNS_PKT_SZ sizeof(dns_pkt)

/* USER MACRO */
#define DNS_GET_ID(dp)		(dp)->pkt_hdr.id
#define DNS_GET_QR(dp)		(dp)->pkt_hdr.qr
#define DNS_GET_OPCODE(dp)	(dp)->pkt_hdr.opcode
#define DNS_GET_AA(dp)		(dp)->pkt_hdr.aa
#define DNS_GET_TC(dp)		(dp)->pkt_hdr.tc
#define DNS_GET_RD(dp)		(dp)->pkt_hdr.rd
#define DNS_GET_RA(dp)		(dp)->pkt_hdr.ra
#define DNS_GET_Z(dp)		(dp)->pkt_hdr.z
#define DNS_GET_RCODE(dp)	(dp)->pkt_hdr.rcode
#define DNS_GET_QDCOUNT(dp)	(dp)->pkt_hdr.qdcount
#define DNS_GET_ANCOUNT(dp)	(dp)->pkt_hdr.ancount
#define DNS_GET_NSCOUNT(dp)	(dp)->pkt_hdr.nscount
#define DNS_GET_ARCOUNT(dp)	(dp)->pkt_hdr.arcount

#define DNS_SET_ID(dp,x)	(dp)->pkt_hdr.id=x
#define DNS_SET_QR(dp,x)	(dp)->pkt_hdr.qr=x
#define DNS_SET_OPCODE(dp,x)	(dp)->pkt_hdr.opcode=x
#define DNS_SET_AA(dp,x)	(dp)->pkt_hdr.aa=x
#define DNS_SET_TC(dp,x)	(dp)->pkt_hdr.tc=x
#define DNS_SET_RD(dp,x)	(dp)->pkt_hdr.rd=x
#define DNS_SET_RA(dp,x)	(dp)->pkt_hdr.ra=x
#define DNS_SET_Z(dp,x)		(dp)->pkt_hdr.z=x
#define DNS_SET_RCODE(dp,x)	(dp)->pkt_hdr.rcode=x
#define DNS_SET_QDCOUNT(dp,x)	(dp)->pkt_hdr.qdcount=x
#define DNS_SET_ANCOUNT(dp,x)	(dp)->pkt_hdr.ancount=x
#define DNS_SET_NSCOUNT(dp,x)	(dp)->pkt_hdr.nscount=x
#define DNS_SET_ARCOUNT(dp,x)	(dp)->pkt_hdr.arcount=x

#define DP_ADD_ANSWER(dp)       dns_add_a(&((dp)->pkt_answ));DP_ANCOUNT(dp)+=1;
#define DP_ADD_AUTH(dp)         dns_add_a(&((dp)->pkt_auth));DP_NSCOUNT(dp)+=1;
#define DP_ADD_ADD(dp)          dns_add_a(&((dp)->pkt_add));DP_ARCOUNT(dp)+=1;


	/* Functions */
int getlblptr(char *buf);
int read_label_octet(const char *src, char *dst, int limit);
int lbltoname(char *buf, char *start_pkt, char *dst, int limit);
int swap_straddr(char *src, char *dst);
int swap_straddr6(char *src, char *dst);
int rm_inv_prefix(char *src, char *dst);
int add_inv_prefix(char *s, int family);
int swapped_straddr(char *src, char *dst);
int swapped_straddr_pref(char *src, char *dst, int family);
int nametolbl(char *name, char *dst);
int d_hdr_u(char *buf, dns_pkt_hdr * dph);
int d_qst_u(char *start_buf, char *buf, dns_pkt * dp, int limit_len);
int d_qsts_u(char *start_buf, char *buf, dns_pkt * dp, int limit_len);
int d_a_u(char *start_buf, char *buf, dns_pkt_a ** dpa_orig,
		  int limit_len);
int d_as_u(char *start_buf, char *buf, dns_pkt_a ** dpa, int limit_len,
		   int count);
int d_u(char *buf, int pktlen, dns_pkt ** dpp);
int d_hdr_p(dns_pkt * dp, char *buf);
int d_qst_p(dns_pkt_qst * dpq, char *buf, int limitlen);
int d_qsts_p(dns_pkt * dp, char *buf, int limitlen);
int d_a_p(dns_pkt_a * dpa, char *buf, int limitlen);
int d_as_p(dns_pkt_a * dpa, char *buf, int limitlen, int count);
int d_p(dns_pkt * dp, char *buf);
dns_pkt *create_dns_pkt(void);
dns_pkt_qst *create_dns_pkt_qst(void);
dns_pkt_a *create_dns_pkt_a(void);
dns_pkt_qst *dns_add_qst(dns_pkt * dp);
void dns_del_last_qst(dns_pkt * dp);
dns_pkt_a *dns_add_a(dns_pkt_a ** dpa);
void dns_a_default_fill(dns_pkt * dp, dns_pkt_a * dpa);
void destroy_dns_pkt(dns_pkt * dp);


#endif							/* DNSLIB_H */