/*-
 * SPDX-License-Identifier: (ISC AND BSD-3-Clause)
 *
 * Portions Copyright (C) 2004, 2005, 2008, 2009  Internet Systems Consortium, Inc. ("ISC")
 * Portions Copyright (C) 1995-2003  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC 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.
 */

/*
 * Copyright (c) 1983, 1987, 1989
 *    The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*%
 *      $Id: resolv.h,v 1.30 2009/03/03 01:52:48 each Exp $
 */

#ifndef _RESOLV_H_
#define _RESOLV_H_

#include <sys/param.h>
#include <sys/types.h>
#include <sys/cdefs.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/nameser.h>

/*%
 * Revision information.  This is the release date in YYYYMMDD format.
 * It can change every day so the right thing to do with it is use it
 * in preprocessor commands such as "#if (__RES > 19931104)".  Do not
 * compare for equality; rather, use it to determine whether your resolver
 * is new enough to contain a certain feature.
 */

#define __RES   20090302

/*%
 * This used to be defined in res_query.c, now it's in herror.c.
 * [XXX no it's not.  It's in irs/irs_data.c]
 * It was
 * never extern'd by any *.h file before it was placed here.  For thread
 * aware programs, the last h_errno value set is stored in res->h_errno.
 *
 * XXX: There doesn't seem to be a good reason for exposing RES_SET_H_ERRNO
 *      (and __h_errno_set) to the public via <resolv.h>.
 * XXX: __h_errno_set is really part of IRS, not part of the resolver.
 *      If somebody wants to build and use a resolver that doesn't use IRS,
 *      what do they do?  Perhaps something like
 *              #ifdef WANT_IRS
 *              # define RES_SET_H_ERRNO(r,x) __h_errno_set(r,x)
 *              #else
 *              # define RES_SET_H_ERRNO(r,x) (h_errno = (r)->res_h_errno = (x))
 *              #endif
 */

#define RES_SET_H_ERRNO(r,x) __h_errno_set(r,x)
struct __res_state; /*%< forward */
__BEGIN_DECLS
void __h_errno_set(struct __res_state *, int);
__END_DECLS

/*%
 * Resolver configuration file.
 * Normally not present, but may contain the address of the
 * initial name server(s) to query and the domain search list.
 */

#ifndef _PATH_RESCONF
#define _PATH_RESCONF        "/etc/resolv.conf"
#endif

typedef enum { res_goahead, res_nextns, res_modified, res_done, res_error }
        res_sendhookact;

typedef res_sendhookact (*res_send_qhook)(struct sockaddr * const *,
                                          const u_char **, int *,
                                          u_char *, int, int *);

typedef res_sendhookact (*res_send_rhook)(const struct sockaddr *,
                                          const u_char *, int, u_char *,
                                          int, int *);

struct res_sym {
        int             number;    /*%< Identifying number, like T_MX */
        const char *    name;      /*%< Its symbolic name, like "MX" */
        const char *    humanname; /*%< Its fun name, like "mail exchanger" */
};

/*%
 * Global defines and variables for resolver stub.
 */
#define MAXNS                   3       /*%< max # name servers we'll track */
#define MAXDFLSRCH              3       /*%< # default domain levels to try */
#define MAXDNSRCH               6       /*%< max # domains in search path */
#define LOCALDOMAINPARTS        2       /*%< min levels in name that is "local" */
#define RES_TIMEOUT             5       /*%< min. seconds between retries */
#define MAXRESOLVSORT           10      /*%< number of net to sort on */
#define RES_MAXNDOTS            15      /*%< should reflect bit field size */
#define RES_MAXRETRANS          30      /*%< only for resolv.conf/RES_OPTIONS */
#define RES_MAXRETRY            5       /*%< only for resolv.conf/RES_OPTIONS */
#define RES_DFLRETRY            2       /*%< Default #/tries. */
#define RES_MAXTIME             65535   /*%< Infinity, in milliseconds. */
struct __res_state_ext;

struct __res_state {
        int     retrans;                /*%< retransmission time interval */
        int     retry;                  /*%< number of times to retransmit */
        /*
         * XXX: If `sun' is defined, `options' and `pfcode' are
         * defined as u_int in original BIND9 distribution.  However,
         * it breaks binary backward compatibility against FreeBSD's
         * resolver.  So, we changed not to see `sun'.
         */
#if defined(sun) && 0
        u_int   options;                /*%< option flags - see below. */
#else
        u_long  options;                /*%< option flags - see below. */
#endif
        int     nscount;                /*%< number of name servers */
        struct sockaddr_in
                nsaddr_list[MAXNS];     /*%< address of name server */
#define nsaddr  nsaddr_list[0]          /*%< for backward compatibility */
        u_short id;                     /*%< current message id */
        char    *dnsrch[MAXDNSRCH+1];   /*%< components of domain to search */
        char    defdname[256];          /*%< default domain (deprecated) */
#if defined(sun) && 0
        u_int   pfcode;                 /*%< RES_PRF_ flags - see below. */
#else
        u_long  pfcode;                 /*%< RES_PRF_ flags - see below. */
#endif
        unsigned ndots:4;               /*%< threshold for initial abs. query */
        unsigned nsort:4;               /*%< number of elements in sort_list[] */
        char    unused[3];
        struct {
                struct in_addr  addr;
                u_int32_t       mask;
        } sort_list[MAXRESOLVSORT];
        res_send_qhook qhook;           /*%< query hook */
        res_send_rhook rhook;           /*%< response hook */
        int     res_h_errno;            /*%< last one set for this context */
        int     _vcsock;                /*%< PRIVATE: for res_send VC i/o */
        u_int   _flags;                 /*%< PRIVATE: see below */
        u_int   _pad;                   /*%< make _u 64 bit aligned */
        union {
                /* On an 32-bit arch this means 512b total. */
                char    pad[72 - 4*sizeof (int) - 3*sizeof (void *)];
                struct {
                        u_int16_t               nscount;
                        u_int16_t               nstimes[MAXNS]; /*%< ms. */
                        int                     nssocks[MAXNS];
                        struct __res_state_ext *ext;    /*%< extension for IPv6 */
                } _ext;
        } _u;
        u_char  *_rnd;                  /*%< PRIVATE: random state (unused) */
};

typedef struct __res_state *res_state;

union res_sockaddr_union {
        struct sockaddr_in      sin;
#ifdef IN6ADDR_ANY_INIT
        struct sockaddr_in6     sin6;
#endif
#ifdef ISC_ALIGN64
        int64_t                 __align64;      /*%< 64bit alignment */
#else
        int32_t                 __align32;      /*%< 32bit alignment */
#endif
        char                    __space[128];   /*%< max size */
};

/*%
 * Resolver flags (used to be discrete per-module statics ints).
 */
#define RES_F_VC        0x00000001      /*%< socket is TCP */
#define RES_F_CONN      0x00000002      /*%< socket is connected */
#define RES_F_EDNS0ERR  0x00000004      /*%< EDNS0 caused errors */
#define RES_F__UNUSED   0x00000008      /*%< (unused) */
#define RES_F_LASTMASK  0x000000F0      /*%< ordinal server of last res_nsend */
#define RES_F_LASTSHIFT 4               /*%< bit position of LASTMASK "flag" */
#define RES_GETLAST(res) (((res)._flags & RES_F_LASTMASK) >> RES_F_LASTSHIFT)

/* res_findzonecut2() options */
#define RES_EXHAUSTIVE  0x00000001      /*%< always do all queries */
#define RES_IPV4ONLY    0x00000002      /*%< IPv4 only */
#define RES_IPV6ONLY    0x00000004      /*%< IPv6 only */

/*%
 * Resolver options (keep these in synch with res_debug.c, please)
 */
#define RES_INIT        0x00000001      /*%< address initialized */
#define RES_DEBUG       0x00000002      /*%< print debug messages */
#define RES_AAONLY      0x00000004      /*%< authoritative answers only (!IMPL)*/
#define RES_USEVC       0x00000008      /*%< use virtual circuit */
#define RES_PRIMARY     0x00000010      /*%< query primary server only (!IMPL) */
#define RES_IGNTC       0x00000020      /*%< ignore truncation errors */
#define RES_RECURSE     0x00000040      /*%< recursion desired */
#define RES_DEFNAMES    0x00000080      /*%< use default domain name */
#define RES_STAYOPEN    0x00000100      /*%< Keep TCP socket open */
#define RES_DNSRCH      0x00000200      /*%< search up local domain tree */
#define RES_INSECURE1   0x00000400      /*%< type 1 security disabled */
#define RES_INSECURE2   0x00000800      /*%< type 2 security disabled */
#define RES_NOALIASES   0x00001000      /*%< shuts off HOSTALIASES feature */
#define RES_USE_INET6   0x00002000      /*%< use/map IPv6 in gethostbyname() */
#define RES_ROTATE      0x00004000      /*%< rotate ns list after each query */
#define RES_NOCHECKNAME 0x00008000      /*%< do not check names for sanity. */
#define RES_KEEPTSIG    0x00010000      /*%< do not strip TSIG records */
#define RES_BLAST       0x00020000      /*%< blast all recursive servers */
#define RES_NSID        0x00040000      /*%< request name server ID */
#define RES_NOTLDQUERY  0x00100000      /*%< don't unqualified name as a tld */
#define RES_USE_DNSSEC  0x00200000      /*%< use DNSSEC using OK bit in OPT */
/* #define RES_DEBUG2   0x00400000 */   /* nslookup internal */
/* KAME extensions: use higher bit to avoid conflict with ISC use */
#define RES_USE_DNAME   0x10000000      /*%< use DNAME */
#define RES_USE_EDNS0   0x40000000      /*%< use EDNS0 if configured */
#define RES_NO_NIBBLE2  0x80000000      /*%< disable alternate nibble lookup */

#define RES_DEFAULT     (RES_RECURSE | RES_DEFNAMES | \
                         RES_DNSRCH | RES_NO_NIBBLE2)

/*%
 * Resolver "pfcode" values.  Used by dig.
 */
#define RES_PRF_STATS   0x00000001
#define RES_PRF_UPDATE  0x00000002
#define RES_PRF_CLASS   0x00000004
#define RES_PRF_CMD     0x00000008
#define RES_PRF_QUES    0x00000010
#define RES_PRF_ANS     0x00000020
#define RES_PRF_AUTH    0x00000040
#define RES_PRF_ADD     0x00000080
#define RES_PRF_HEAD1   0x00000100
#define RES_PRF_HEAD2   0x00000200
#define RES_PRF_TTLID   0x00000400
#define RES_PRF_HEADX   0x00000800
#define RES_PRF_QUERY   0x00001000
#define RES_PRF_REPLY   0x00002000
#define RES_PRF_INIT    0x00004000
#define RES_PRF_TRUNC   0x00008000
/*                      0x00010000      */

/* Things involving an internal (static) resolver context. */
__BEGIN_DECLS
extern struct __res_state *__res_state(void);
__END_DECLS
#define _res (*__res_state())

#ifndef __BIND_NOSTATIC
#define fp_nquery               __fp_nquery
#define fp_query                __fp_query
#define hostalias               __hostalias
#define p_query                 __p_query
#define res_close               __res_close
#define res_init                __res_init
#define res_isourserver         __res_isourserver
#define res_mkquery             __res_mkquery
#define res_opt                 __res_opt
#define res_query               __res_query
#define res_querydomain         __res_querydomain
#define res_search              __res_search
#define res_send                __res_send
#define res_sendsigned          __res_sendsigned

__BEGIN_DECLS
void            fp_nquery(const u_char *, int, FILE *);
void            fp_query(const u_char *, FILE *);
const char *    hostalias(const char *);
void            p_query(const u_char *);
void            res_close(void);
int             res_init(void);
int             res_isourserver(const struct sockaddr_in *);
int             res_mkquery(int, const char *, int, int, const u_char *,
                                 int, const u_char *, u_char *, int);
int             res_opt(int, u_char *, int, int);
int             res_query(const char *, int, int, u_char *, int);
int             res_querydomain(const char *, const char *, int, int,
                                     u_char *, int);
int             res_search(const char *, int, int, u_char *, int);
int             res_send(const u_char *, int, u_char *, int);
int             res_sendsigned(const u_char *, int, ns_tsig_key *,
                                    u_char *, int);
__END_DECLS
#endif

#if !defined(SHARED_LIBBIND) || defined(LIB)
/*
 * If libbind is a shared object (well, DLL anyway)
 * these externs break the linker when resolv.h is
 * included by a lib client (like named)
 * Make them go away if a client is including this
 *
 */
extern const struct res_sym __p_key_syms[];
extern const struct res_sym __p_cert_syms[];
extern const struct res_sym __p_class_syms[];
extern const struct res_sym __p_type_syms[];
extern const struct res_sym __p_rcode_syms[];
#endif /* SHARED_LIBBIND */

#define b64_ntop                __b64_ntop
#define b64_pton                __b64_pton
#define dn_comp                 __dn_comp
#define dn_count_labels         __dn_count_labels
#define dn_expand               __dn_expand
#define dn_skipname             __dn_skipname
#define fp_resstat              __fp_resstat
#define loc_aton                __loc_aton
#define loc_ntoa                __loc_ntoa
#define p_cdname                __p_cdname
#define p_cdnname               __p_cdnname
#define p_class                 __p_class
#define p_fqname                __p_fqname
#define p_fqnname               __p_fqnname
#define p_option                __p_option
#define p_secstodate            __p_secstodate
#define p_section               __p_section
#define p_time                  __p_time
#define p_type                  __p_type
#define p_rcode                 __p_rcode
#define p_sockun                __p_sockun
#define putlong                 __putlong
#define putshort                __putshort
#define res_dnok                __res_dnok
#if 0
#define res_findzonecut         __res_findzonecut
#endif
#define res_findzonecut2        __res_findzonecut2
#define res_hnok                __res_hnok
#define res_hostalias           __res_hostalias
#define res_mailok              __res_mailok
#define res_nameinquery         __res_nameinquery
#define res_nclose              __res_nclose
#define res_ninit               __res_ninit
#define res_nmkquery            __res_nmkquery
#define res_pquery              __res_pquery
#define res_nquery              __res_nquery
#define res_nquerydomain        __res_nquerydomain
#define res_nsearch             __res_nsearch
#define res_nsend               __res_nsend
#if 0
#define res_nsendsigned         __res_nsendsigned
#endif
#define res_nisourserver        __res_nisourserver
#define res_ownok               __res_ownok
#define res_queriesmatch        __res_queriesmatch
#define res_randomid            __res_randomid
#define res_nrandomid           __res_nrandomid
#define sym_ntop                __sym_ntop
#define sym_ntos                __sym_ntos
#define sym_ston                __sym_ston
#define res_nopt                __res_nopt
#define res_nopt_rdata          __res_nopt_rdata
#define res_ndestroy            __res_ndestroy
#define res_nametoclass         __res_nametoclass
#define res_nametotype          __res_nametotype
#define res_setservers          __res_setservers
#define res_getservers          __res_getservers
#if 0
#define res_buildprotolist      __res_buildprotolist
#define res_destroyprotolist    __res_destroyprotolist
#define res_destroyservicelist  __res_destroyservicelist
#define res_get_nibblesuffix    __res_get_nibblesuffix
#define res_get_nibblesuffix2   __res_get_nibblesuffix2
#endif
#define res_ourserver_p         __res_ourserver_p
#if 0
#define res_protocolname        __res_protocolname
#define res_protocolnumber      __res_protocolnumber
#endif
#define res_send_setqhook       __res_send_setqhook
#define res_send_setrhook       __res_send_setrhook
#if 0
#define res_servicename         __res_servicename
#define res_servicenumber       __res_servicenumber
#endif
__BEGIN_DECLS
int             res_hnok(const char *);
int             res_ownok(const char *);
int             res_mailok(const char *);
int             res_dnok(const char *);
int             sym_ston(const struct res_sym *, const char *, int *);
const char *    sym_ntos(const struct res_sym *, int, int *);
const char *    sym_ntop(const struct res_sym *, int, int *);
int             b64_ntop(u_char const *, size_t, char *, size_t);
int             b64_pton(char const *, u_char *, size_t);
int             loc_aton(const char *, u_char *);
const char *    loc_ntoa(const u_char *, char *);
int             dn_skipname(const u_char *, const u_char *);
void            putlong(u_int32_t, u_char *);
void            putshort(u_int16_t, u_char *);
#ifndef __ultrix__
u_int16_t       _getshort(const u_char *);
u_int32_t       _getlong(const u_char *);
#endif
const char *    p_class(int);
const char *    p_time(u_int32_t);
const char *    p_type(int);
const char *    p_rcode(int);
const char *    p_sockun(union res_sockaddr_union, char *, size_t);
const u_char *  p_cdnname(const u_char *, const u_char *, int, FILE *);
const u_char *  p_cdname(const u_char *, const u_char *, FILE *);
const u_char *  p_fqnname(const u_char *, const u_char *, int, char *, int);
const u_char *  p_fqname(const u_char *, const u_char *, FILE *);
const char *    p_option(u_long);
char *          p_secstodate(u_long);
int             dn_count_labels(const char *);
int             dn_comp(const char *, u_char *, int, u_char **, u_char **);
int             dn_expand(const u_char *, const u_char *, const u_char *,
                          char *, int);
u_int           res_randomid(void);
u_int           res_nrandomid(res_state);
int             res_nameinquery(const char *, int, int, const u_char *,
                                const u_char *);
int             res_queriesmatch(const u_char *, const u_char *,
                                 const u_char *, const u_char *);
const char *    p_section(int, int);
/* Things involving a resolver context. */
int             res_ninit(res_state);
int             res_nisourserver(const res_state, const struct sockaddr_in *);
void            fp_resstat(const res_state, FILE *);
void            res_pquery(const res_state, const u_char *, int, FILE *);
const char *    res_hostalias(const res_state, const char *, char *, size_t);
int             res_nquery(res_state, const char *, int, int, u_char *, int);
int             res_nsearch(res_state, const char *, int, int, u_char *, int);
int             res_nquerydomain(res_state, const char *, const char *,
                                 int, int, u_char *, int);
int             res_nmkquery(res_state, int, const char *, int, int,
                             const u_char *, int, const u_char *,
                             u_char *, int);
int             res_nsend(res_state, const u_char *, int, u_char *, int);
#if 0
int             res_nsendsigned(res_state, const u_char *, int,
                                ns_tsig_key *, u_char *, int);
int             res_findzonecut(res_state, const char *, ns_class, int,
                                char *, size_t, struct in_addr *, int);
#endif
int             res_findzonecut2(res_state, const char *, ns_class, int,
                                 char *, size_t,
                                 union res_sockaddr_union *, int);
void            res_nclose(res_state);
int             res_nopt(res_state, int, u_char *, int, int);
int             res_nopt_rdata(res_state, int, u_char *, int, u_char *,
                               u_short, u_short, u_char *);
void            res_send_setqhook(res_send_qhook);
void            res_send_setrhook(res_send_rhook);
int             __res_vinit(res_state, int);
#if 0
void            res_destroyservicelist(void);
const char *    res_servicename(u_int16_t, const char *);
const char *    res_protocolname(int);
void            res_destroyprotolist(void);
void            res_buildprotolist(void);
const char *    res_get_nibblesuffix(res_state);
const char *    res_get_nibblesuffix2(res_state);
#endif
void            res_ndestroy(res_state);
u_int16_t       res_nametoclass(const char *, int *);
u_int16_t       res_nametotype(const char *, int *);
void            res_setservers(res_state, const union res_sockaddr_union *,
                               int);
int             res_getservers(res_state, union res_sockaddr_union *, int);
__END_DECLS

#endif /* !_RESOLV_H_ */
/*! \file */