/*

 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")

 *

 * SPDX-License-Identifier: MPL-2.0

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, you can obtain one at https://mozilla.org/MPL/2.0/.

 *

 * See the COPYRIGHT file distributed with this work for additional

 * information regarding copyright ownership.

 */

/*! \file */

#include <isc/async.h>

#include <isc/loop.h>

#include <dns/resolver.h>

#include <dns/view.h>

#include <dns/zone.h>

#include <dns/zonefetch.h>

#include "zone_p.h"

void

dns_zonefetch_run(void *arg) {

  dns_zonefetch_t *fetch = (dns_zonefetch_t *)arg;

  dns_zone_t *zone;

  dns_view_t *view;

  isc_loop_t *loop;

  isc_result_t result;

  dns_resolver_t *resolver = NULL;

  zone = fetch->zone;

  if (dns__zone_exiting(zone)) {

    result = ISC_R_SHUTTINGDOWN;

    goto cancel;

  }

  view = dns_zone_getview(zone);

  loop = dns_zone_getloop(zone);

  INSIST(view != NULL);

  INSIST(loop != NULL);

  fetch->fetchmethods.start_fetch(fetch);

  result = dns_view_getresolver(view, &resolver);

  if (result != ISC_R_SUCCESS) {

    goto cancel;

  }

  if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {

    char namebuf[DNS_NAME_FORMATSIZE];

    char typebuf[DNS_RDATATYPE_FORMATSIZE];

    dns_name_format(fetch->qname, namebuf, sizeof(namebuf));

    dns_rdatatype_format(fetch->qtype, typebuf, sizeof(typebuf));

    dns_zone_logc(zone, DNS_LOGCATEGORY_DNSSEC, ISC_LOG_DEBUG(3),

            "Do fetch for %s/%s request", namebuf, typebuf);

  }

  /*

   * Use of DNS_FETCHOPT_NOCACHED is essential here.  If it is not

   * set and the cache still holds a non-expired, validated version

   * of the RRset being queried for by the time the response is

   * received, the cached RRset will be passed to dns_zonefetch_done()

   * instead of the one received in the response as the latter will

   * have a lower trust level due to not being validated until

   * dns_zonefetch_done() is called.

   */

  INSIST((fetch->options & DNS_FETCHOPT_NOCACHED) != 0);

  result = dns_resolver_createfetch(

    resolver, fetch->qname, fetch->qtype, NULL, NULL, NULL, NULL, 0,

    fetch->options, 0, NULL, NULL, loop, dns_zonefetch_done, fetch,

    NULL, &fetch->rrset, &fetch->sigset, &fetch->fetch);

  dns_resolver_detach(&resolver);

cancel:

  if (result == ISC_R_SUCCESS) {

    return;

  } else if (result != ISC_R_SHUTTINGDOWN) {

    char namebuf[DNS_NAME_FORMATSIZE];

    char typebuf[DNS_RDATATYPE_FORMATSIZE];

    dns_name_format(fetch->qname, namebuf, sizeof(namebuf));

    dns_rdatatype_format(fetch->qtype, typebuf, sizeof(typebuf));

    dns_zone_log(zone, ISC_LOG_WARNING,

           "Failed fetch for %s/%s request", namebuf,

           typebuf);

  }

  /*

   * Fetch failed, cancel.

   */

  dns__zone_lock(zone);

  dns_name_t *zname = dns_fixedname_name(&fetch->name);

  isc_mem_t *mctx = dns_zone_getmctx(zone);

  bool free_needed;

  isc_refcount_decrement(dns__zone_irefs(zone));

  dns_name_free(zname, mctx);

  fetch->fetchmethods.cancel_fetch(fetch);

  isc_mem_putanddetach(&fetch->mctx, fetch, sizeof(*fetch));

  free_needed = dns__zone_free_check(zone);

  dns__zone_unlock(zone);

  if (free_needed) {

    dns__zone_free(zone);

  }

}

void

dns_zonefetch_done(void *arg) {

  dns_fetchresponse_t *resp = (dns_fetchresponse_t *)arg;

  isc_result_t result = ISC_R_NOMORE;

  isc_result_t eresult;

  dns_zonefetch_t *fetch = NULL;

  dns_zone_t *zone = NULL;

  dns_view_t *view = NULL;

  isc_mem_t *mctx = NULL;

  dns_name_t *zname = NULL;

  dns_rdataset_t *rrset = NULL;

  dns_rdataset_t *sigset = NULL;

  INSIST(resp != NULL);

  fetch = resp->arg;

  INSIST(fetch != NULL);

  mctx = fetch->mctx;

  zone = fetch->zone;

  zname = dns_fixedname_name(&fetch->name);

  rrset = &fetch->rrset;

  sigset = &fetch->sigset;

  view = dns_zone_getview(zone);

  eresult = resp->result;

  /* Free resources which are not of interest */

  if (resp->node != NULL) {

    dns_db_detachnode(&resp->node);

  }

  if (resp->db != NULL) {

    dns_db_detach(&resp->db);

  }

  dns_resolver_destroyfetch(&fetch->fetch);

  dns__zone_lock(zone);

  if (dns__zone_exiting(zone) || view == NULL) {

    goto cleanup;

  }

  result = fetch->fetchmethods.done_fetch(fetch, eresult);

cleanup:

  isc_refcount_decrement(dns__zone_irefs(zone));

  if (dns_rdataset_isassociated(rrset)) {

    dns_rdataset_disassociate(rrset);

  }

  if (dns_rdataset_isassociated(sigset)) {

    dns_rdataset_disassociate(sigset);

  }

  fetch->fetchmethods.cleanup_fetch(fetch);

  dns_resolver_freefresp(&resp);

  if (result == DNS_R_CONTINUE) {

    dns__zone_unlock(zone);

    fetch->fetchmethods.continue_fetch(fetch);

  } else {

    bool free_needed = false;

    dns_name_free(zname, mctx);

    isc_mem_putanddetach(&fetch->mctx, fetch,

             sizeof(dns_zonefetch_t));

    free_needed = dns__zone_free_check(zone);

    dns__zone_unlock(zone);

    if (free_needed) {

      dns__zone_free(zone);

    }

  }

}

static void

zonefetch_schedule(dns_zonefetch_t *fetch, dns_name_t *name) {

  dns_zone_t *zone = fetch->zone;

  isc_refcount_increment0(dns__zone_irefs(zone));

  if (name != NULL) {

    dns_name_t *fname = dns_fixedname_initname(&fetch->name);

    dns_name_dup(name, fetch->mctx, fname);

  }

  dns_rdataset_init(&fetch->rrset);

  dns_rdataset_init(&fetch->sigset);

  isc_async_run(dns_zone_getloop(zone), dns_zonefetch_run, fetch);

}

void

dns_zonefetch_schedule(dns_zonefetch_t *fetch, dns_name_t *name) {

  REQUIRE(fetch != NULL);

  REQUIRE(name != NULL);

  zonefetch_schedule(fetch, name);

}

void

dns_zonefetch_reschedule(dns_zonefetch_t *fetch) {

  REQUIRE(fetch != NULL);

  zonefetch_schedule(fetch, NULL);

}

isc_result_t

dns_zonefetch_verify(dns_zonefetch_t *fetch, isc_result_t eresult,

         dns_trust_t trust) {

  char namebuf[DNS_NAME_FORMATSIZE];

  char typebuf[DNS_RDATATYPE_FORMATSIZE];

  dns_rdataset_t *rrset = NULL;

  dns_rdataset_t *sigset = NULL;

  REQUIRE(fetch != NULL);

  rrset = &fetch->rrset;

  sigset = &fetch->sigset;

  dns_name_format(fetch->qname, namebuf, sizeof(namebuf));

  dns_rdatatype_format(fetch->qtype, typebuf, sizeof(typebuf));

  if (eresult != ISC_R_SUCCESS) {

    dns_zone_logc(fetch->zone, DNS_LOGCATEGORY_DNSSEC,

            ISC_LOG_WARNING, "Unable to fetch %s/%s: %s",

            namebuf, typebuf, isc_result_totext(eresult));

    return eresult;

  }

  /* No records found */

  if (!dns_rdataset_isassociated(rrset)) {

    dns_zone_logc(fetch->zone, DNS_LOGCATEGORY_DNSSEC,

            ISC_LOG_WARNING, "No %s records found for '%s'",

            typebuf, namebuf);

    return ISC_R_NOTFOUND;

  }

  /* No RRSIGs found */

  if (!dns_rdataset_isassociated(sigset)) {

    dns_zone_logc(fetch->zone, DNS_LOGCATEGORY_DNSSEC,

            ISC_LOG_WARNING, "No %s RRSIGs found for '%s'",

            typebuf, namebuf);

    return DNS_R_NOVALIDSIG;

  }

  /* Check trust level */

  if (rrset->trust < trust) {

    dns_zone_logc(fetch->zone, DNS_LOGCATEGORY_DNSSEC,

            ISC_LOG_WARNING,

            "Invalid %s RRset for '%s' trust level %u",

            typebuf, namebuf, rrset->trust);

    return DNS_R_NOVALIDSIG;

  }

  return ISC_R_SUCCESS;

}