/***************************************************************************

 *                                  _   _ ____  _

 *  Project                     ___| | | |  _ \| |

 *                             / __| | | | |_) | |

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.

 *

 * This software is licensed as described in the file COPYING, which

 * you should have received as part of this distribution. The terms

 * are also available at https://curl.se/docs/copyright.html.

 *

 * You may opt to use, copy, modify, merge, publish, distribute and/or sell

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

 * furnished to do so, under the terms of the COPYING file.

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY

 * KIND, either express or implied.

 *

 * SPDX-License-Identifier: curl

 *

 ***************************************************************************/

#include "curl_setup.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 __VMS

#include <in.h>

#include <inet.h>

#endif

#ifdef USE_ARES

#include <ares.h>

#endif

#include "urldata.h"

#include "connect.h"

#include "curl_trc.h"

#include "hostip.h"

#include "multiif.h"

#include "progress.h"

#include "select.h"

#include "url.h"

/***********************************************************************

 * Only for builds using asynchronous name resolves

 **********************************************************************/

#ifdef CURLRES_ASYNCH

timediff_t Curl_async_timeleft_ms(struct Curl_easy *data,

                                  struct Curl_resolv_async *async)

{

  if(async->timeout_ms) {

    timediff_t elapsed_ms =

      curlx_ptimediff_ms(Curl_pgrs_now(data), &async->start);

    return async->timeout_ms - elapsed_ms;

  }

  return Curl_timeleft_ms(data);

}

#ifdef USE_ARES

#if ARES_VERSION < 0x011000

#error "requires c-ares 1.16.0 or newer"

#endif

/*

 * Curl_ares_pollset() is called when the outside world (using

 * curl_multi_fdset()) wants to get our fd_set setup and we are talking with

 * ares. The caller must make sure that this function is only called when we

 * have a working ares channel.

 *

 * Returns: sockets-in-use-bitmap

 */

CURLcode Curl_ares_pollset(struct Curl_easy *data,

                           ares_channel channel,

                           struct easy_pollset *ps)

{

  curl_socket_t sockets[16];  /* ARES documented limit */

  unsigned int bitmap, i;

  CURLcode result = CURLE_OK;

  DEBUGASSERT(channel);

  if(!channel)

    return CURLE_FAILED_INIT;

  bitmap = ares_getsock(channel, (ares_socket_t *)sockets,

                        CURL_ARRAYSIZE(sockets));

  for(i = 0; i < CURL_ARRAYSIZE(sockets); ++i) {

    int flags = 0;

    if(ARES_GETSOCK_READABLE(bitmap, i))

      flags |= CURL_POLL_IN;

    if(ARES_GETSOCK_WRITABLE(bitmap, i))

      flags |= CURL_POLL_OUT;

    if(!flags)

      break;

    result = Curl_pollset_change(data, ps, sockets[i], flags, 0);

    if(result)

      return result;

  }

  return result;

}

timediff_t Curl_ares_timeout_ms(struct Curl_easy *data,

                                struct Curl_resolv_async *async,

                                ares_channel channel)

{

  timediff_t async_timeout_ms;

  DEBUGASSERT(channel);

  if(!channel)

    return -1;

  async_timeout_ms = Curl_async_timeleft_ms(data, async);

  if((async_timeout_ms > 0) && (async_timeout_ms < INT_MAX)) {

    struct timeval timebuf;

    struct timeval *timeout;

    struct timeval end = { (int)async_timeout_ms / 1000,

                           ((int)async_timeout_ms % 1000) * 1000 };

    timeout = ares_timeout(channel, &end, &timebuf);

    if(timeout)

      return curlx_tvtoms(timeout);

  }

  return async_timeout_ms;

}

/*

 * Curl_ares_perform()

 *

 * 1) Ask ares what sockets it currently plays with, then

 * 2) wait for the timeout period to check for action on ares' sockets.

 * 3) tell ares to act on all the sockets marked as "with action"

 *

 * return number of sockets it worked on, or -1 on error

 */

int Curl_ares_perform(ares_channel channel, timediff_t timeout_ms)

{

  int nfds;

  int bitmask;

  ares_socket_t socks[ARES_GETSOCK_MAXNUM];

  struct pollfd pfd[ARES_GETSOCK_MAXNUM];

  int i;

  int num = 0;

  if(!channel)

    return 0;

  bitmask = ares_getsock(channel, socks, ARES_GETSOCK_MAXNUM);

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

    pfd[i].events = 0;

    pfd[i].revents = 0;

    if(ARES_GETSOCK_READABLE(bitmask, i)) {

      pfd[i].fd = socks[i];

      pfd[i].events |= POLLRDNORM | POLLIN;

    }

    if(ARES_GETSOCK_WRITABLE(bitmask, i)) {

      pfd[i].fd = socks[i];

      pfd[i].events |= POLLWRNORM | POLLOUT;

    }

    if(pfd[i].events)

      num++;

    else

      break;

  }

  if(num) {

    nfds = Curl_poll(pfd, (unsigned int)num, timeout_ms);

    if(nfds < 0)

      return -1;

  }

  else

    nfds = 0;

  if(!nfds)

    /* Call ares_process() unconditionally here, even if we timed out

       above, as otherwise the ares name resolve will not timeout! */

    ares_process_fd(channel, ARES_SOCKET_BAD, ARES_SOCKET_BAD);

  else {

    /* move through the descriptors and ask for processing on them */

    for(i = 0; i < num; i++)

      ares_process_fd(channel,

                      (pfd[i].revents & (POLLRDNORM | POLLIN)) ?

                      pfd[i].fd : ARES_SOCKET_BAD,

                      (pfd[i].revents & (POLLWRNORM | POLLOUT)) ?

                      pfd[i].fd : ARES_SOCKET_BAD);

  }

  return nfds;

}

#endif /* USE_ARES */

#endif /* CURLRES_ASYNCH */

#ifdef USE_CURL_ASYNC

#include "doh.h"

void Curl_async_shutdown(struct Curl_easy *data,

                         struct Curl_resolv_async *async)

{

  if(async) {

    CURL_TRC_DNS(data, "[%u] shutdown async", async->id);

    async->shutdown = TRUE;

#ifdef USE_RESOLV_ARES

    Curl_async_ares_shutdown(data, async);

#endif

#ifdef USE_RESOLV_THREADED

    Curl_async_thrdd_shutdown(data, async);

#endif

#ifndef CURL_DISABLE_DOH

    Curl_doh_cleanup(data, async);

#endif

  }

}

void Curl_async_destroy(struct Curl_easy *data,

                        struct Curl_resolv_async *async)

{

  if(async) {

    CURL_TRC_DNS(data, "[%u] destroy async", async->id);

    async->shutdown = TRUE;

#ifdef USE_RESOLV_ARES

    Curl_async_ares_destroy(data, async);

#endif

#ifdef USE_RESOLV_THREADED

    Curl_async_thrdd_destroy(data, async);

#endif

#ifndef CURL_DISABLE_DOH

    Curl_doh_cleanup(data, async);

#endif

    curlx_safefree(async);

  }

}

CURLcode Curl_async_failed(struct Curl_easy *data,

                           struct Curl_resolv_async *async,

                           const char *detail)

{

  const char *host_or_proxy = "host";

  CURLcode result = CURLE_COULDNT_RESOLVE_HOST;

#ifndef CURL_DISABLE_PROXY

  if(async->for_proxy) {

    host_or_proxy = "proxy";

    result = CURLE_COULDNT_RESOLVE_PROXY;

  }

#endif

  failf(data, "Could not resolve %s: %s%s%s%s",

        host_or_proxy, async->hostname,

        detail ? " (" : "", detail ? detail : "", detail ? ")" : "");

  return result;

}

#endif /* USE_CURL_ASYNC */