/*      $OpenBSD: common.h,v 1.2 2018/12/15 15:16:12 eric Exp $ */
/*
 * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#include <sys/types.h>
#include <sys/socket.h>

#include <arpa/nameser.h>

#include <netinet/in.h>

#include <netdb.h>


#define unpack_rr               __unpack_rr
#define unpack_header           __unpack_header
#define packed_init             __packed_init
#define unpack_query            __unpack_query
#define sockaddr_from_str       __sockaddr_from_str
#define print_addr              __print_addr

extern int long_err;
extern int gai_errno;
extern int rrset_errno;

const char *classtostr(uint16_t);
const char *typetostr(uint16_t);
const char *rcodetostr(uint16_t);

uint16_t strtotype(const char*);
uint16_t strtoclass(const char*);
int strtoresopt(const char*);
void parseresopt(const char*);

void    print_rrsetinfo(struct rrsetinfo *);
void    print_addrinfo(struct addrinfo *);
void    print_errors(void);
void    print_hostent(struct hostent *);
void    print_netent(struct netent *);

int     sockaddr_from_str(struct sockaddr *, int, const char *);
int     addr_from_str(char *, int *, int *, const char *);
char*   gethostarg(char *);

#define QR_MASK         (0x1 << 15)
#define OPCODE_MASK     (0xf << 11)
#define AA_MASK         (0x1 << 10)
#define TC_MASK         (0x1 <<  9)
#define RD_MASK         (0x1 <<  8)
#define RA_MASK         (0x1 <<  7)
#define Z_MASK          (0x7 <<  4)
#define RCODE_MASK      (0xf)

#define OPCODE(v)       ((v) & OPCODE_MASK)
#define RCODE(v)        ((v) & RCODE_MASK)


struct packed {
        char            *data;
        size_t           len;
        size_t           offset;
        const char      *err;
};

struct header {
        uint16_t        id;
        uint16_t        flags;
        uint16_t        qdcount;
        uint16_t        ancount;
        uint16_t        nscount;
        uint16_t        arcount;
};

struct query {
        char            q_dname[MAXDNAME];
        uint16_t        q_type;
        uint16_t        q_class;
};

struct rr {
        char            rr_dname[MAXDNAME];
        uint16_t        rr_type;
        uint16_t        rr_class;
        uint32_t        rr_ttl;
        union {
                struct {
                        char    cname[MAXDNAME];
                } cname;
                struct {
                        uint16_t        preference;
                        char            exchange[MAXDNAME];
                } mx;
                struct {
                        char    nsname[MAXDNAME];
                } ns;
                struct {
                        char    ptrname[MAXDNAME];
                } ptr;
                struct {
                        char            mname[MAXDNAME];
                        char            rname[MAXDNAME];
                        uint32_t        serial;
                        uint32_t        refresh;
                        uint32_t        retry;
                        uint32_t        expire;
                        uint32_t        minimum;
                } soa;
                struct {
                        struct in_addr  addr;
                } in_a;
                struct {
                        struct in6_addr addr6;
                } in_aaaa;
                struct {
                        uint16_t         rdlen;
                        const void      *rdata;
                } other;
        } rr;
};

void    packed_init(struct packed*, char*, size_t);
int     pack_header(struct packed*, const struct header*);
int     pack_query(struct packed*, uint16_t, uint16_t, const char*);
int     unpack_header(struct packed*, struct header*);
int     unpack_query(struct packed*, struct query*);
int     unpack_rr(struct packed*, struct rr*);