--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/lib/asyn-ares.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,828 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2019, 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.haxx.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.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+/***********************************************************************
+ * Only for ares-enabled builds
+ * And only for functions that fulfill the asynch resolver backend API
+ * as defined in asyn.h, nothing else belongs in this file!
+ **********************************************************************/
+
+#ifdef CURLRES_ARES
+
+#include <limits.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 HAVE_PROCESS_H
+#include <process.h>
+#endif
+
+#if (defined(NETWARE) && defined(__NOVELL_LIBC__))
+#undef in_addr_t
+#define in_addr_t unsigned long
+#endif
+
+#include "urldata.h"
+#include "sendf.h"
+#include "hostip.h"
+#include "hash.h"
+#include "share.h"
+#include "strerror.h"
+#include "url.h"
+#include "multiif.h"
+#include "inet_pton.h"
+#include "connect.h"
+#include "select.h"
+#include "progress.h"
+
+#  if defined(CURL_STATICLIB) && !defined(CARES_STATICLIB) && \
+     (defined(WIN32) || defined(__SYMBIAN32__))
+#    define CARES_STATICLIB
+#  endif
+#  include <ares.h>
+#  include <ares_version.h> /* really old c-ares didn't include this by
+                               itself */
+
+#if ARES_VERSION >= 0x010500
+/* c-ares 1.5.0 or later, the callback proto is modified */
+#define HAVE_CARES_CALLBACK_TIMEOUTS 1
+#endif
+
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+
+struct ResolverResults {
+  int num_pending; /* number of ares_gethostbyname() requests */
+  Curl_addrinfo *temp_ai; /* intermediary result while fetching c-ares parts */
+  int last_status;
+  struct curltime happy_eyeballs_dns_time; /* when this timer started, or 0 */
+};
+
+/* How long we are willing to wait for additional parallel responses after
+   obtaining a "definitive" one.
+
+   This is intended to equal the c-ares default timeout.  cURL always uses that
+   default value.  Unfortunately, c-ares doesn't expose its default timeout in
+   its API, but it is officially documented as 5 seconds.
+
+   See query_completed_cb() for an explanation of how this is used.
+ */
+#define HAPPY_EYEBALLS_DNS_TIMEOUT 5000
+
+/*
+ * Curl_resolver_global_init() - the generic low-level asynchronous name
+ * resolve API.  Called from curl_global_init() to initialize global resolver
+ * environment.  Initializes ares library.
+ */
+int Curl_resolver_global_init(void)
+{
+#ifdef CARES_HAVE_ARES_LIBRARY_INIT
+  if(ares_library_init(ARES_LIB_INIT_ALL)) {
+    return CURLE_FAILED_INIT;
+  }
+#endif
+  return CURLE_OK;
+}
+
+/*
+ * Curl_resolver_global_cleanup()
+ *
+ * Called from curl_global_cleanup() to destroy global resolver environment.
+ * Deinitializes ares library.
+ */
+void Curl_resolver_global_cleanup(void)
+{
+#ifdef CARES_HAVE_ARES_LIBRARY_CLEANUP
+  ares_library_cleanup();
+#endif
+}
+
+
+static void Curl_ares_sock_state_cb(void *data, ares_socket_t socket_fd,
+                                    int readable, int writable)
+{
+  struct Curl_easy *easy = data;
+  if(!readable && !writable) {
+    DEBUGASSERT(easy);
+    Curl_multi_closed(easy, socket_fd);
+  }
+}
+
+/*
+ * Curl_resolver_init()
+ *
+ * Called from curl_easy_init() -> Curl_open() to initialize resolver
+ * URL-state specific environment ('resolver' member of the UrlState
+ * structure).  Fills the passed pointer by the initialized ares_channel.
+ */
+CURLcode Curl_resolver_init(struct Curl_easy *easy, void **resolver)
+{
+  int status;
+  struct ares_options options;
+  int optmask = ARES_OPT_SOCK_STATE_CB;
+  options.sock_state_cb = Curl_ares_sock_state_cb;
+  options.sock_state_cb_data = easy;
+  status = ares_init_options((ares_channel*)resolver, &options, optmask);
+  if(status != ARES_SUCCESS) {
+    if(status == ARES_ENOMEM)
+      return CURLE_OUT_OF_MEMORY;
+    else
+      return CURLE_FAILED_INIT;
+  }
+  return CURLE_OK;
+  /* make sure that all other returns from this function should destroy the
+     ares channel before returning error! */
+}
+
+/*
+ * Curl_resolver_cleanup()
+ *
+ * Called from curl_easy_cleanup() -> Curl_close() to cleanup resolver
+ * URL-state specific environment ('resolver' member of the UrlState
+ * structure).  Destroys the ares channel.
+ */
+void Curl_resolver_cleanup(void *resolver)
+{
+  ares_destroy((ares_channel)resolver);
+}
+
+/*
+ * Curl_resolver_duphandle()
+ *
+ * Called from curl_easy_duphandle() to duplicate resolver URL-state specific
+ * environment ('resolver' member of the UrlState structure).  Duplicates the
+ * 'from' ares channel and passes the resulting channel to the 'to' pointer.
+ */
+CURLcode Curl_resolver_duphandle(struct Curl_easy *easy, void **to, void *from)
+{
+  (void)from;
+  /*
+   * it would be better to call ares_dup instead, but right now
+   * it is not possible to set 'sock_state_cb_data' outside of
+   * ares_init_options
+   */
+  return Curl_resolver_init(easy, to);
+}
+
+static void destroy_async_data(struct Curl_async *async);
+
+/*
+ * Cancel all possibly still on-going resolves for this connection.
+ */
+void Curl_resolver_cancel(struct connectdata *conn)
+{
+  if(conn->data && conn->data->state.resolver)
+    ares_cancel((ares_channel)conn->data->state.resolver);
+  destroy_async_data(&conn->async);
+}
+
+/*
+ * We're equivalent to Curl_resolver_cancel() for the c-ares resolver.  We
+ * never block.
+ */
+void Curl_resolver_kill(struct connectdata *conn)
+{
+  /* We don't need to check the resolver state because we can be called safely
+     at any time and we always do the same thing. */
+  Curl_resolver_cancel(conn);
+}
+
+/*
+ * destroy_async_data() cleans up async resolver data.
+ */
+static void destroy_async_data(struct Curl_async *async)
+{
+  free(async->hostname);
+
+  if(async->os_specific) {
+    struct ResolverResults *res = (struct ResolverResults *)async->os_specific;
+    if(res) {
+      if(res->temp_ai) {
+        Curl_freeaddrinfo(res->temp_ai);
+        res->temp_ai = NULL;
+      }
+      free(res);
+    }
+    async->os_specific = NULL;
+  }
+
+  async->hostname = NULL;
+}
+
+/*
+ * Curl_resolver_getsock() is called when someone from the outside world
+ * (using curl_multi_fdset()) wants to get our fd_set setup and we're 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
+ */
+
+int Curl_resolver_getsock(struct connectdata *conn,
+                          curl_socket_t *socks)
+{
+  struct timeval maxtime;
+  struct timeval timebuf;
+  struct timeval *timeout;
+  long milli;
+  int max = ares_getsock((ares_channel)conn->data->state.resolver,
+                         (ares_socket_t *)socks, MAX_SOCKSPEREASYHANDLE);
+
+  maxtime.tv_sec = CURL_TIMEOUT_RESOLVE;
+  maxtime.tv_usec = 0;
+
+  timeout = ares_timeout((ares_channel)conn->data->state.resolver, &maxtime,
+                         &timebuf);
+  milli = (timeout->tv_sec * 1000) + (timeout->tv_usec/1000);
+  if(milli == 0)
+    milli += 10;
+  Curl_expire(conn->data, milli, EXPIRE_ASYNC_NAME);
+
+  return max;
+}
+
+/*
+ * waitperform()
+ *
+ * 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
+ */
+
+static int waitperform(struct connectdata *conn, int timeout_ms)
+{
+  struct Curl_easy *data = conn->data;
+  int nfds;
+  int bitmask;
+  ares_socket_t socks[ARES_GETSOCK_MAXNUM];
+  struct pollfd pfd[ARES_GETSOCK_MAXNUM];
+  int i;
+  int num = 0;
+
+  bitmask = ares_getsock((ares_channel)data->state.resolver, 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 != 0)
+      num++;
+    else
+      break;
+  }
+
+  if(num)
+    nfds = Curl_poll(pfd, num, timeout_ms);
+  else
+    nfds = 0;
+
+  if(!nfds)
+    /* Call ares_process() unconditonally here, even if we simply timed out
+       above, as otherwise the ares name resolve won't timeout! */
+    ares_process_fd((ares_channel)data->state.resolver, 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((ares_channel)data->state.resolver,
+                      (pfd[i].revents & (POLLRDNORM|POLLIN))?
+                      pfd[i].fd:ARES_SOCKET_BAD,
+                      (pfd[i].revents & (POLLWRNORM|POLLOUT))?
+                      pfd[i].fd:ARES_SOCKET_BAD);
+  }
+  return nfds;
+}
+
+/*
+ * Curl_resolver_is_resolved() is called repeatedly to check if a previous
+ * name resolve request has completed. It should also make sure to time-out if
+ * the operation seems to take too long.
+ *
+ * Returns normal CURLcode errors.
+ */
+CURLcode Curl_resolver_is_resolved(struct connectdata *conn,
+                                   struct Curl_dns_entry **dns)
+{
+  struct Curl_easy *data = conn->data;
+  struct ResolverResults *res = (struct ResolverResults *)
+    conn->async.os_specific;
+  CURLcode result = CURLE_OK;
+
+  if(dns)
+    *dns = NULL;
+
+  waitperform(conn, 0);
+
+  /* Now that we've checked for any last minute results above, see if there are
+     any responses still pending when the EXPIRE_HAPPY_EYEBALLS_DNS timer
+     expires. */
+  if(res
+     && res->num_pending
+     /* This is only set to non-zero if the timer was started. */
+     && (res->happy_eyeballs_dns_time.tv_sec
+         || res->happy_eyeballs_dns_time.tv_usec)
+     && (Curl_timediff(Curl_now(), res->happy_eyeballs_dns_time)
+         >= HAPPY_EYEBALLS_DNS_TIMEOUT)) {
+    /* Remember that the EXPIRE_HAPPY_EYEBALLS_DNS timer is no longer
+       running. */
+    memset(
+      &res->happy_eyeballs_dns_time, 0, sizeof(res->happy_eyeballs_dns_time));
+
+    /* Cancel the raw c-ares request, which will fire query_completed_cb() with
+       ARES_ECANCELLED synchronously for all pending responses.  This will
+       leave us with res->num_pending == 0, which is perfect for the next
+       block. */
+    ares_cancel((ares_channel)data->state.resolver);
+    DEBUGASSERT(res->num_pending == 0);
+  }
+
+  if(res && !res->num_pending) {
+    if(dns) {
+      (void)Curl_addrinfo_callback(conn, res->last_status, res->temp_ai);
+      /* temp_ai ownership is moved to the connection, so we need not free-up
+         them */
+      res->temp_ai = NULL;
+    }
+    if(!conn->async.dns) {
+      failf(data, "Could not resolve: %s (%s)",
+            conn->async.hostname, ares_strerror(conn->async.status));
+      result = conn->bits.proxy?CURLE_COULDNT_RESOLVE_PROXY:
+        CURLE_COULDNT_RESOLVE_HOST;
+    }
+    else if(dns)
+      *dns = conn->async.dns;
+
+    destroy_async_data(&conn->async);
+  }
+
+  return result;
+}
+
+/*
+ * Curl_resolver_wait_resolv()
+ *
+ * Waits for a resolve to finish. This function should be avoided since using
+ * this risk getting the multi interface to "hang".
+ *
+ * If 'entry' is non-NULL, make it point to the resolved dns entry
+ *
+ * Returns CURLE_COULDNT_RESOLVE_HOST if the host was not resolved,
+ * CURLE_OPERATION_TIMEDOUT if a time-out occurred, or other errors.
+ */
+CURLcode Curl_resolver_wait_resolv(struct connectdata *conn,
+                                   struct Curl_dns_entry **entry)
+{
+  CURLcode result = CURLE_OK;
+  struct Curl_easy *data = conn->data;
+  timediff_t timeout;
+  struct curltime now = Curl_now();
+  struct Curl_dns_entry *temp_entry;
+
+  if(entry)
+    *entry = NULL; /* clear on entry */
+
+  timeout = Curl_timeleft(data, &now, TRUE);
+  if(timeout < 0) {
+    /* already expired! */
+    connclose(conn, "Timed out before name resolve started");
+    return CURLE_OPERATION_TIMEDOUT;
+  }
+  if(!timeout)
+    timeout = CURL_TIMEOUT_RESOLVE * 1000; /* default name resolve timeout */
+
+  /* Wait for the name resolve query to complete. */
+  while(!result) {
+    struct timeval *tvp, tv, store;
+    int itimeout;
+    int timeout_ms;
+
+    itimeout = (timeout > (long)INT_MAX) ? INT_MAX : (int)timeout;
+
+    store.tv_sec = itimeout/1000;
+    store.tv_usec = (itimeout%1000)*1000;
+
+    tvp = ares_timeout((ares_channel)data->state.resolver, &store, &tv);
+
+    /* use the timeout period ares returned to us above if less than one
+       second is left, otherwise just use 1000ms to make sure the progress
+       callback gets called frequent enough */
+    if(!tvp->tv_sec)
+      timeout_ms = (int)(tvp->tv_usec/1000);
+    else
+      timeout_ms = 1000;
+
+    waitperform(conn, timeout_ms);
+    result = Curl_resolver_is_resolved(conn, entry?&temp_entry:NULL);
+
+    if(result || conn->async.done)
+      break;
+
+    if(Curl_pgrsUpdate(conn))
+      result = CURLE_ABORTED_BY_CALLBACK;
+    else {
+      struct curltime now2 = Curl_now();
+      timediff_t timediff = Curl_timediff(now2, now); /* spent time */
+      if(timediff <= 0)
+        timeout -= 1; /* always deduct at least 1 */
+      else if(timediff > timeout)
+        timeout = -1;
+      else
+        timeout -= (long)timediff;
+      now = now2; /* for next loop */
+    }
+    if(timeout < 0)
+      result = CURLE_OPERATION_TIMEDOUT;
+  }
+  if(result)
+    /* failure, so we cancel the ares operation */
+    ares_cancel((ares_channel)data->state.resolver);
+
+  /* Operation complete, if the lookup was successful we now have the entry
+     in the cache. */
+  if(entry)
+    *entry = conn->async.dns;
+
+  if(result)
+    /* close the connection, since we can't return failure here without
+       cleaning up this connection properly. */
+    connclose(conn, "c-ares resolve failed");
+
+  return result;
+}
+
+/* Connects results to the list */
+static void compound_results(struct ResolverResults *res,
+                             Curl_addrinfo *ai)
+{
+  Curl_addrinfo *ai_tail;
+  if(!ai)
+    return;
+  ai_tail = ai;
+
+  while(ai_tail->ai_next)
+    ai_tail = ai_tail->ai_next;
+
+  /* Add the new results to the list of old results. */
+  ai_tail->ai_next = res->temp_ai;
+  res->temp_ai = ai;
+}
+
+/*
+ * ares_query_completed_cb() is the callback that ares will call when
+ * the host query initiated by ares_gethostbyname() from Curl_getaddrinfo(),
+ * when using ares, is completed either successfully or with failure.
+ */
+static void query_completed_cb(void *arg,  /* (struct connectdata *) */
+                               int status,
+#ifdef HAVE_CARES_CALLBACK_TIMEOUTS
+                               int timeouts,
+#endif
+                               struct hostent *hostent)
+{
+  struct connectdata *conn = (struct connectdata *)arg;
+  struct ResolverResults *res;
+
+#ifdef HAVE_CARES_CALLBACK_TIMEOUTS
+  (void)timeouts; /* ignored */
+#endif
+
+  if(ARES_EDESTRUCTION == status)
+    /* when this ares handle is getting destroyed, the 'arg' pointer may not
+       be valid so only defer it when we know the 'status' says its fine! */
+    return;
+
+  res = (struct ResolverResults *)conn->async.os_specific;
+  if(res) {
+    res->num_pending--;
+
+    if(CURL_ASYNC_SUCCESS == status) {
+      Curl_addrinfo *ai = Curl_he2ai(hostent, conn->async.port);
+      if(ai) {
+        compound_results(res, ai);
+      }
+    }
+    /* A successful result overwrites any previous error */
+    if(res->last_status != ARES_SUCCESS)
+      res->last_status = status;
+
+    /* If there are responses still pending, we presume they must be the
+       complementary IPv4 or IPv6 lookups that we started in parallel in
+       Curl_resolver_getaddrinfo() (for Happy Eyeballs).  If we've got a
+       "definitive" response from one of a set of parallel queries, we need to
+       think about how long we're willing to wait for more responses. */
+    if(res->num_pending
+       /* Only these c-ares status values count as "definitive" for these
+          purposes.  For example, ARES_ENODATA is what we expect when there is
+          no IPv6 entry for a domain name, and that's not a reason to get more
+          aggressive in our timeouts for the other response.  Other errors are
+          either a result of bad input (which should affect all parallel
+          requests), local or network conditions, non-definitive server
+          responses, or us cancelling the request. */
+       && (status == ARES_SUCCESS || status == ARES_ENOTFOUND)) {
+      /* Right now, there can only be up to two parallel queries, so don't
+         bother handling any other cases. */
+      DEBUGASSERT(res->num_pending == 1);
+
+      /* It's possible that one of these parallel queries could succeed
+         quickly, but the other could always fail or timeout (when we're
+         talking to a pool of DNS servers that can only successfully resolve
+         IPv4 address, for example).
+
+         It's also possible that the other request could always just take
+         longer because it needs more time or only the second DNS server can
+         fulfill it successfully.  But, to align with the philosophy of Happy
+         Eyeballs, we don't want to wait _too_ long or users will think
+         requests are slow when IPv6 lookups don't actually work (but IPv4 ones
+         do).
+
+         So, now that we have a usable answer (some IPv4 addresses, some IPv6
+         addresses, or "no such domain"), we start a timeout for the remaining
+         pending responses.  Even though it is typical that this resolved
+         request came back quickly, that needn't be the case.  It might be that
+         this completing request didn't get a result from the first DNS server
+         or even the first round of the whole DNS server pool.  So it could
+         already be quite some time after we issued the DNS queries in the
+         first place.  Without modifying c-ares, we can't know exactly where in
+         its retry cycle we are.  We could guess based on how much time has
+         gone by, but it doesn't really matter.  Happy Eyeballs tells us that,
+         given usable information in hand, we simply don't want to wait "too
+         much longer" after we get a result.
+
+         We simply wait an additional amount of time equal to the default
+         c-ares query timeout.  That is enough time for a typical parallel
+         response to arrive without being "too long".  Even on a network
+         where one of the two types of queries is failing or timing out
+         constantly, this will usually mean we wait a total of the default
+         c-ares timeout (5 seconds) plus the round trip time for the successful
+         request, which seems bearable.  The downside is that c-ares might race
+         with us to issue one more retry just before we give up, but it seems
+         better to "waste" that request instead of trying to guess the perfect
+         timeout to prevent it.  After all, we don't even know where in the
+         c-ares retry cycle each request is.
+      */
+      res->happy_eyeballs_dns_time = Curl_now();
+      Curl_expire(
+        conn->data, HAPPY_EYEBALLS_DNS_TIMEOUT, EXPIRE_HAPPY_EYEBALLS_DNS);
+    }
+  }
+}
+
+/*
+ * Curl_resolver_getaddrinfo() - when using ares
+ *
+ * Returns name information about the given hostname and port number. If
+ * successful, the 'hostent' is returned and the forth argument will point to
+ * memory we need to free after use. That memory *MUST* be freed with
+ * Curl_freeaddrinfo(), nothing else.
+ */
+Curl_addrinfo *Curl_resolver_getaddrinfo(struct connectdata *conn,
+                                         const char *hostname,
+                                         int port,
+                                         int *waitp)
+{
+  char *bufp;
+  struct Curl_easy *data = conn->data;
+  struct in_addr in;
+  int family = PF_INET;
+#ifdef ENABLE_IPV6 /* CURLRES_IPV6 */
+  struct in6_addr in6;
+#endif /* CURLRES_IPV6 */
+
+  *waitp = 0; /* default to synchronous response */
+
+  /* First check if this is an IPv4 address string */
+  if(Curl_inet_pton(AF_INET, hostname, &in) > 0) {
+    /* This is a dotted IP address 123.123.123.123-style */
+    return Curl_ip2addr(AF_INET, &in, hostname, port);
+  }
+
+#ifdef ENABLE_IPV6 /* CURLRES_IPV6 */
+  /* Otherwise, check if this is an IPv6 address string */
+  if(Curl_inet_pton (AF_INET6, hostname, &in6) > 0)
+    /* This must be an IPv6 address literal.  */
+    return Curl_ip2addr(AF_INET6, &in6, hostname, port);
+
+  switch(conn->ip_version) {
+  default:
+#if ARES_VERSION >= 0x010601
+    family = PF_UNSPEC; /* supported by c-ares since 1.6.1, so for older
+                           c-ares versions this just falls through and defaults
+                           to PF_INET */
+    break;
+#endif
+  case CURL_IPRESOLVE_V4:
+    family = PF_INET;
+    break;
+  case CURL_IPRESOLVE_V6:
+    family = PF_INET6;
+    break;
+  }
+#endif /* CURLRES_IPV6 */
+
+  bufp = strdup(hostname);
+  if(bufp) {
+    struct ResolverResults *res = NULL;
+    free(conn->async.hostname);
+    conn->async.hostname = bufp;
+    conn->async.port = port;
+    conn->async.done = FALSE;   /* not done */
+    conn->async.status = 0;     /* clear */
+    conn->async.dns = NULL;     /* clear */
+    res = calloc(sizeof(struct ResolverResults), 1);
+    if(!res) {
+      free(conn->async.hostname);
+      conn->async.hostname = NULL;
+      return NULL;
+    }
+    conn->async.os_specific = res;
+
+    /* initial status - failed */
+    res->last_status = ARES_ENOTFOUND;
+#ifdef ENABLE_IPV6 /* CURLRES_IPV6 */
+    if(family == PF_UNSPEC) {
+      if(Curl_ipv6works()) {
+        res->num_pending = 2;
+
+        /* areschannel is already setup in the Curl_open() function */
+        ares_gethostbyname((ares_channel)data->state.resolver, hostname,
+                            PF_INET, query_completed_cb, conn);
+        ares_gethostbyname((ares_channel)data->state.resolver, hostname,
+                            PF_INET6, query_completed_cb, conn);
+      }
+      else {
+        res->num_pending = 1;
+
+        /* areschannel is already setup in the Curl_open() function */
+        ares_gethostbyname((ares_channel)data->state.resolver, hostname,
+                            PF_INET, query_completed_cb, conn);
+      }
+    }
+    else
+#endif /* CURLRES_IPV6 */
+    {
+      res->num_pending = 1;
+
+      /* areschannel is already setup in the Curl_open() function */
+      ares_gethostbyname((ares_channel)data->state.resolver, hostname, family,
+                         query_completed_cb, conn);
+    }
+
+    *waitp = 1; /* expect asynchronous response */
+  }
+  return NULL; /* no struct yet */
+}
+
+CURLcode Curl_set_dns_servers(struct Curl_easy *data,
+                              char *servers)
+{
+  CURLcode result = CURLE_NOT_BUILT_IN;
+  int ares_result;
+
+  /* If server is NULL or empty, this would purge all DNS servers
+   * from ares library, which will cause any and all queries to fail.
+   * So, just return OK if none are configured and don't actually make
+   * any changes to c-ares.  This lets c-ares use it's defaults, which
+   * it gets from the OS (for instance from /etc/resolv.conf on Linux).
+   */
+  if(!(servers && servers[0]))
+    return CURLE_OK;
+
+#if (ARES_VERSION >= 0x010704)
+#if (ARES_VERSION >= 0x010b00)
+  ares_result = ares_set_servers_ports_csv(data->state.resolver, servers);
+#else
+  ares_result = ares_set_servers_csv(data->state.resolver, servers);
+#endif
+  switch(ares_result) {
+  case ARES_SUCCESS:
+    result = CURLE_OK;
+    break;
+  case ARES_ENOMEM:
+    result = CURLE_OUT_OF_MEMORY;
+    break;
+  case ARES_ENOTINITIALIZED:
+  case ARES_ENODATA:
+  case ARES_EBADSTR:
+  default:
+    result = CURLE_BAD_FUNCTION_ARGUMENT;
+    break;
+  }
+#else /* too old c-ares version! */
+  (void)data;
+  (void)(ares_result);
+#endif
+  return result;
+}
+
+CURLcode Curl_set_dns_interface(struct Curl_easy *data,
+                                const char *interf)
+{
+#if (ARES_VERSION >= 0x010704)
+  if(!interf)
+    interf = "";
+
+  ares_set_local_dev((ares_channel)data->state.resolver, interf);
+
+  return CURLE_OK;
+#else /* c-ares version too old! */
+  (void)data;
+  (void)interf;
+  return CURLE_NOT_BUILT_IN;
+#endif
+}
+
+CURLcode Curl_set_dns_local_ip4(struct Curl_easy *data,
+                                const char *local_ip4)
+{
+#if (ARES_VERSION >= 0x010704)
+  struct in_addr a4;
+
+  if((!local_ip4) || (local_ip4[0] == 0)) {
+    a4.s_addr = 0; /* disabled: do not bind to a specific address */
+  }
+  else {
+    if(Curl_inet_pton(AF_INET, local_ip4, &a4) != 1) {
+      return CURLE_BAD_FUNCTION_ARGUMENT;
+    }
+  }
+
+  ares_set_local_ip4((ares_channel)data->state.resolver, ntohl(a4.s_addr));
+
+  return CURLE_OK;
+#else /* c-ares version too old! */
+  (void)data;
+  (void)local_ip4;
+  return CURLE_NOT_BUILT_IN;
+#endif
+}
+
+CURLcode Curl_set_dns_local_ip6(struct Curl_easy *data,
+                                const char *local_ip6)
+{
+#if (ARES_VERSION >= 0x010704) && defined(ENABLE_IPV6)
+  unsigned char a6[INET6_ADDRSTRLEN];
+
+  if((!local_ip6) || (local_ip6[0] == 0)) {
+    /* disabled: do not bind to a specific address */
+    memset(a6, 0, sizeof(a6));
+  }
+  else {
+    if(Curl_inet_pton(AF_INET6, local_ip6, a6) != 1) {
+      return CURLE_BAD_FUNCTION_ARGUMENT;
+    }
+  }
+
+  ares_set_local_ip6((ares_channel)data->state.resolver, a6);
+
+  return CURLE_OK;
+#else /* c-ares version too old! */
+  (void)data;
+  (void)local_ip6;
+  return CURLE_NOT_BUILT_IN;
+#endif
+}
+#endif /* CURLRES_ARES */