/* MIT License

 *

 * Copyright (c) 2019 Andrew Selivanov

 * Copyright (c) 2023 Brad House

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice (including the next

 * paragraph) shall be included in all copies or substantial portions of the

 * Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE.

 *

 * SPDX-License-Identifier: MIT

 */

#include "ares_private.h"

#ifdef HAVE_NETINET_IN_H

#  include <netinet/in.h>

#endif

#ifdef HAVE_NETDB_H

#  include <netdb.h>

#endif

#ifdef HAVE_ARPA_INET_H

#  include <arpa/inet.h>

#endif

#ifdef HAVE_STRINGS_H

#  include <strings.h>

#endif

#ifdef HAVE_LIMITS_H

#  include <limits.h>

#endif

ares_status_t ares_parse_into_addrinfo(const ares_dns_record_t *dnsrec,

                                       ares_bool_t    cname_only_is_enodata,

                                       unsigned short port,

                                       struct ares_addrinfo *ai)

{

  ares_status_t               status;

  size_t                      i;

  size_t                      ancount;

  const char                 *hostname  = NULL;

  ares_bool_t                 got_a     = ARES_FALSE;

  ares_bool_t                 got_aaaa  = ARES_FALSE;

  ares_bool_t                 got_cname = ARES_FALSE;

  struct ares_addrinfo_cname *cnames    = NULL;

  struct ares_addrinfo_node  *nodes     = NULL;

  /* Save question hostname */

  status = ares_dns_record_query_get(dnsrec, 0, &hostname, NULL, NULL);

  if (status != ARES_SUCCESS) {

    goto done; /* LCOV_EXCL_LINE: DefensiveCoding */

  }

  ancount = ares_dns_record_rr_cnt(dnsrec, ARES_SECTION_ANSWER);

  if (ancount == 0) {

    status = ARES_ENODATA;

    goto done;

  }

  for (i = 0; i < ancount; i++) {

    ares_dns_rec_type_t  rtype;

    const ares_dns_rr_t *rr =

      ares_dns_record_rr_get_const(dnsrec, ARES_SECTION_ANSWER, i);

    if (ares_dns_rr_get_class(rr) != ARES_CLASS_IN) {

      continue;

    }

    rtype = ares_dns_rr_get_type(rr);

    /* Issue #683

     * Old code did this hostname sanity check, however it appears this is

     * flawed logic.  Other resolvers don't do this sanity check.  Leaving

     * this code commented out for future reference.

     *

     * rname = ares_dns_rr_get_name(rr);

     * if ((rtype == ARES_REC_TYPE_A || rtype == ARES_REC_TYPE_AAAA) &&

     *     !ares_strcaseeq(rname, hostname)) {

     *   continue;

     * }

     */

    if (rtype == ARES_REC_TYPE_CNAME) {

      struct ares_addrinfo_cname *cname;

      got_cname = ARES_TRUE;

      /* replace hostname with data from cname */

      hostname = ares_dns_rr_get_str(rr, ARES_RR_CNAME_CNAME);

      cname = ares_append_addrinfo_cname(&cnames);

      if (cname == NULL) {

        status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */

        goto done;            /* LCOV_EXCL_LINE: OutOfMemory */

      }

      cname->ttl   = (int)ares_dns_rr_get_ttl(rr);

      cname->alias = ares_strdup(ares_dns_rr_get_name(rr));

      if (cname->alias == NULL) {

        status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */

        goto done;            /* LCOV_EXCL_LINE: OutOfMemory */

      }

      cname->name = ares_strdup(hostname);

      if (cname->name == NULL) {

        status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */

        goto done;            /* LCOV_EXCL_LINE: OutOfMemory */

      }

    } else if (rtype == ARES_REC_TYPE_A) {

      got_a = ARES_TRUE;

      status =

        ares_append_ai_node(AF_INET, port, ares_dns_rr_get_ttl(rr),

                            ares_dns_rr_get_addr(rr, ARES_RR_A_ADDR), &nodes);

      if (status != ARES_SUCCESS) {

        goto done; /* LCOV_EXCL_LINE: OutOfMemory */

      }

    } else if (rtype == ARES_REC_TYPE_AAAA) {

      got_aaaa = ARES_TRUE;

      status   = ares_append_ai_node(AF_INET6, port, ares_dns_rr_get_ttl(rr),

                                     ares_dns_rr_get_addr6(rr, ARES_RR_AAAA_ADDR),

                                     &nodes);

      if (status != ARES_SUCCESS) {

        goto done; /* LCOV_EXCL_LINE: OutOfMemory */

      }

    } else {

      continue;

    }

  }

  if (!got_a && !got_aaaa &&

      (!got_cname || (got_cname && cname_only_is_enodata))) {

    status = ARES_ENODATA;

    goto done;

  }

  /* save the hostname as ai->name */

  if (ai->name == NULL || !ares_strcaseeq(ai->name, hostname)) {

    ares_free(ai->name);

    ai->name = ares_strdup(hostname);

    if (ai->name == NULL) {

      status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */

      goto done;            /* LCOV_EXCL_LINE: OutOfMemory */

    }

  }

  if (got_a || got_aaaa) {

    ares_addrinfo_cat_nodes(&ai->nodes, nodes);

    nodes = NULL;

  }

  if (got_cname) {

    ares_addrinfo_cat_cnames(&ai->cnames, cnames);

    cnames = NULL;

  }

done:

  ares_freeaddrinfo_cnames(cnames);

  ares_freeaddrinfo_nodes(nodes);

  /* compatibility */

  if (status == ARES_EBADNAME) {

    status = ARES_EBADRESP;

  }

  return status;

}