/*
 * Copyright (C) 1996-2023 The Squid Software Foundation and contributors
 *
 * Squid software is distributed under GPLv2+ license and includes
 * contributions from numerous individuals and organizations.
 * Please see the COPYING and CONTRIBUTORS files for details.
 */

#ifndef SQUID_SRC_DNS_RFC1035_H
#define SQUID_SRC_DNS_RFC1035_H

#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#if HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#include "rfc2181.h"

/**
 \par RFC 1035 Section 3.1:
 *  To simplify implementations, the total length of a domain name (i.e.,
 *  label octets and label length octets) is restricted to 255 octets or
 *  less.
 *\par
 *  Clarified by RFC 2181 Section 11. (RFC2181_MAXHOSTNAMELEN)
 */
#define RFC1035_MAXHOSTNAMESZ RFC2181_MAXHOSTNAMELEN

#define RFC1035_DEFAULT_PACKET_SZ 512

class rfc1035_rr
{
public:
    char name[RFC1035_MAXHOSTNAMESZ];
    unsigned short type;
    unsigned short _class;
    unsigned int ttl;
    unsigned short rdlength;
    char *rdata;
};

typedef struct _rfc1035_query rfc1035_query;
struct _rfc1035_query {
    char name[RFC1035_MAXHOSTNAMESZ];
    unsigned short qtype;
    unsigned short qclass;
};

typedef struct _rfc1035_message rfc1035_message;
struct _rfc1035_message {
    unsigned short id;
    unsigned int qr:1;
    unsigned int opcode:4;
    unsigned int aa:1;
    unsigned int tc:1;
    unsigned int rd:1;
    unsigned int ra:1;
    unsigned int rcode:4;
    unsigned short qdcount;
    unsigned short ancount;
    unsigned short nscount;
    unsigned short arcount;
    rfc1035_query *query;
    rfc1035_rr *answer;
};

SQUIDCEXTERN ssize_t rfc1035BuildAQuery(const char *hostname,
                                        char *buf,
                                        size_t sz,
                                        unsigned short qid,
                                        rfc1035_query * query,
                                        ssize_t edns_sz);
SQUIDCEXTERN ssize_t rfc1035BuildPTRQuery(const struct in_addr,
        char *buf,
        size_t sz,
        unsigned short qid,
        rfc1035_query * query,
        ssize_t edns_sz);
SQUIDCEXTERN void rfc1035SetQueryID(char *, unsigned short qid);
SQUIDCEXTERN int rfc1035MessageUnpack(const char *buf,
                                      size_t sz,
                                      rfc1035_message ** answer);
SQUIDCEXTERN int rfc1035QueryCompare(const rfc1035_query *, const rfc1035_query *);
SQUIDCEXTERN void rfc1035RRDestroy(rfc1035_rr ** rr, int n);
SQUIDCEXTERN void rfc1035MessageDestroy(rfc1035_message ** message);
SQUIDCEXTERN const char * rfc1035ErrorMessage(int n);

#define RFC1035_TYPE_A 1
#define RFC1035_TYPE_CNAME 5
#define RFC1035_TYPE_PTR 12
#define RFC1035_CLASS_IN 1

/* Child Library RFC3596 Depends on some otherwise internal functions */
SQUIDCEXTERN int rfc1035HeaderPack(char *buf,
                                   size_t sz,
                                   rfc1035_message * hdr);
SQUIDCEXTERN int rfc1035HeaderUnpack(const char *buf,
                                     size_t sz,
                                     unsigned int *off,
                                     rfc1035_message * h);
SQUIDCEXTERN int rfc1035QuestionPack(char *buf,
                                     size_t sz,
                                     const char *name,
                                     const unsigned short type,
                                     const unsigned short _class);
SQUIDCEXTERN int rfc1035RRPack(char *buf, size_t sz, const rfc1035_rr * RR);

#endif /* SQUID_SRC_DNS_RFC1035_H */

