/*      $OpenBSD: asr.h,v 1.2 2019/10/24 05:57:41 otto Exp $    */
/*
 * Copyright (c) 2012-2014 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.
 */

/*
 * Expected fd conditions
 */
#define ASR_WANT_READ   1
#define ASR_WANT_WRITE  2

/*
 * Structure through which asynchronous query results are returned when
 * calling asr_run().
 */
struct asr_result {
        /* Fields set if the query is not done yet (asr_run returns 0) */
        int      ar_cond;       /* ASR_WANT_READ or ASR_WANT_WRITE */
        int      ar_fd;         /* the fd waiting for io condition */
        int      ar_timeout;    /* time to wait for in milliseconds */

        /* Error fields.  Depends on the query type. */
        int      ar_errno;
        int      ar_h_errno;
        int      ar_gai_errno;
        int      ar_rrset_errno;

        /* Result for res_*_async() calls */
        int      ar_count;      /* number of answers in the dns reply */
        int      ar_rcode;      /* response code in the dns reply */
        void    *ar_data;       /* raw reply packet (must be freed) */
        int      ar_datalen;    /* reply packet length */
        struct sockaddr_storage ar_ns; /* nameserver that responded */

        /* Result for other calls. Must be freed properly. */
        struct addrinfo  *ar_addrinfo;
        struct rrsetinfo *ar_rrsetinfo;
        struct hostent   *ar_hostent;
        struct netent    *ar_netent;
};

/*
 * Asynchronous query management.
 */

/* Forward declaration. The API uses opaque pointers as query handles. */
struct asr_query;

void *asr_resolver_from_string(const char *);
void asr_resolver_free(void *);
int asr_run(struct asr_query *, struct asr_result *);
int asr_run_sync(struct asr_query *, struct asr_result *);
void asr_abort(struct asr_query *);

/*
 * Asynchronous version of the resolver functions. Similar prototypes, with
 * an extra context parameter at the end which must currently be set to NULL.
 * All functions return a handle suitable for use with the management functions
 * above.
 */
struct asr_query *res_send_async(const unsigned char *, int, void *);
struct asr_query *res_query_async(const char *, int, int, void *);
struct asr_query *res_search_async(const char *, int, int, void *);

struct asr_query *getrrsetbyname_async(const char *, unsigned int, unsigned int,
    unsigned int, void *);

struct asr_query *gethostbyname_async(const char *, void *);
struct asr_query *gethostbyname2_async(const char *, int, void *);
struct asr_query *gethostbyaddr_async(const void *, socklen_t, int, void *);

struct asr_query *getnetbyname_async(const char *, void *);
struct asr_query *getnetbyaddr_async(in_addr_t, int, void *);

struct asr_query *getaddrinfo_async(const char *, const char *,
    const struct addrinfo *, void *);
struct asr_query *getnameinfo_async(const struct sockaddr *, socklen_t, char *,
    size_t, char *, size_t, int, void *);