/*      $OpenBSD: res_mkquery.c,v 1.14 2021/11/22 20:18:27 jca 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 <netinet/in.h>
#include <arpa/nameser.h> /* for MAXDNAME */
#include <netdb.h>

#include <asr.h>
#include <errno.h>
#include <resolv.h>
#include <string.h>

#include "asr_private.h"

/* This function is apparently needed by some ports. */
int
res_mkquery(int op, const char *dname, int class, int type,
    const unsigned char *data, int datalen, const unsigned char *newrr,
    unsigned char *buf, int buflen)
{
        struct asr_ctx          *ac;
        struct asr_pack          p;
        struct asr_dns_header    h;
        char                     fqdn[MAXDNAME];
        char                     dn[MAXDNAME];

        /* we currently only support QUERY */
        if (op != QUERY || data)
                return (-1);

        if (dname[0] == '\0' || dname[strlen(dname) - 1] != '.') {
                if (strlcpy(fqdn, dname, sizeof(fqdn)) >= sizeof(fqdn) ||
                    strlcat(fqdn, ".", sizeof(fqdn)) >= sizeof(fqdn))
                        return (-1);
                dname = fqdn;
        }

        if (_asr_dname_from_fqdn(dname, dn, sizeof(dn)) == -1)
                return (-1);

        ac = _asr_use_resolver(NULL);

        memset(&h, 0, sizeof h);
        h.id = res_randomid();
        if (ac->ac_options & RES_RECURSE)
                h.flags |= RD_MASK;
        if (ac->ac_options & RES_USE_CD)
                h.flags |= CD_MASK;
        if (ac->ac_options & RES_TRUSTAD)
                h.flags |= AD_MASK;
        h.qdcount = 1;
        if (ac->ac_options & (RES_USE_EDNS0 | RES_USE_DNSSEC))
                h.arcount = 1;

        _asr_pack_init(&p, buf, buflen);
        _asr_pack_header(&p, &h);
        _asr_pack_query(&p, type, class, dn);
        if (ac->ac_options & (RES_USE_EDNS0 | RES_USE_DNSSEC))
                _asr_pack_edns0(&p, MAXPACKETSZ,
                    ac->ac_options & RES_USE_DNSSEC);

        _asr_ctx_unref(ac);

        if (p.err)
                return (-1);

        return (p.offset);
}

/*
 * This function is not documented, but used by sendmail.
 * Put here because it uses asr_private.h too.
 */
int
res_querydomain(const char *name,
    const char *domain,
    int class,
    int type,
    u_char *answer,
    int anslen)
{
        char    fqdn[MAXDNAME], ndom[MAXDNAME];
        size_t  n;

        /* we really want domain to end with a dot for now */
        if (domain && ((n = strlen(domain)) == 0 || domain[n - 1 ] != '.')) {
                if (strlcpy(ndom, domain, sizeof(ndom)) >= sizeof(ndom) ||
                    strlcat(ndom, ".", sizeof(ndom)) >= sizeof(ndom)) {
                        h_errno = NETDB_INTERNAL;
                        errno = EINVAL;
                        return (-1);
                }
                domain = ndom;
        }

        if (_asr_make_fqdn(name, domain, fqdn, sizeof fqdn) == 0) {
                h_errno = NETDB_INTERNAL;
                errno = EINVAL;
                return (-1);
        }

        return (res_query(fqdn, class, type, answer, anslen));
}