Commit 8ab137b2 authored by Tommie Gannert's avatar Tommie Gannert Committed by Daniel Stenberg
Browse files

ares: ask for both IPv4 and IPv6 addresses 

Make the c-ares resolver code ask for both IPv4 and IPv6 addresses when
IPv6 is enabled.

This is a workaround for the missing ares_getaddrinfo() and is a lot
easier to implement.

Note that as long as c-ares returns IPv4 addresses when IPv6 addresses
were requested but missing, this will cause a host's IPv4 addresses to
occur twice in the DNS cache.

URL: http://curl.haxx.se/mail/lib-2010-12/0041.html
parent bcfb9ea3

lib/hostares.c

+23 −6
Original line number Diff line number Diff line
@@ -401,10 +401,27 @@ Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn, 
    conn->async.done = FALSE;   /* not done */

    conn->async.status = 0;     /* clear */

    conn->async.dns = NULL;     /* clear */

    conn->async.temp_ai = NULL; /* clear */



#ifdef ENABLE_IPV6 /* CURLRES_IPV6 */

    if(family == PF_UNSPEC) {

      conn->async.num_pending = 2;



      /* areschannel is already setup in the Curl_open() function */

      ares_gethostbyname(data->state.areschannel, hostname, PF_INET,

                         ares_query_completed_cb, conn);

      ares_gethostbyname(data->state.areschannel, hostname, PF_INET6,

                         ares_query_completed_cb, conn);

    }

    else

#endif /* CURLRES_IPV6 */

    {

      conn->async.num_pending = 1;



      /* areschannel is already setup in the Curl_open() function */

      ares_gethostbyname(data->state.areschannel, hostname, family,

                       (ares_host_callback)ares_query_completed_cb, conn);

                         ares_query_completed_cb, conn);

    }



    *waitp = 1; /* expect asynchronous response */

  }

lib/hostasyn.c

+55 −2
Original line number Diff line number Diff line
@@ -5,7 +5,7 @@ 
 *                            | (__| |_| |  _ <| |___

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

 *

 * Copyright (C) 1998 - 2009, Daniel Stenberg, <daniel@haxx.se>, et al.

 * Copyright (C) 1998 - 2010, 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
@@ -95,6 +95,20 @@ CURLcode Curl_addrinfo_callback(struct connectdata * conn, 
    if(ai) {

      struct SessionHandle *data = conn->data;



#if defined(ENABLE_IPV6) && defined(CURLRES_ARES) /* CURLRES_IPV6 */

      Curl_addrinfo *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 = conn->async.temp_ai;

      conn->async.temp_ai = ai;



      if(--conn->async.num_pending > 0)

        /* We are not done yet. Just return. */

        return CURLE_OK;

#endif

      if(data->share)

        Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
@@ -110,10 +124,49 @@ CURLcode Curl_addrinfo_callback(struct connectdata * conn, 
      if(data->share)

        Curl_share_unlock(data, CURL_LOCK_DATA_DNS);

    }

    else {

#if defined(ENABLE_IPV6) && defined(CURLRES_ARES) /* CURLRES_IPV6 */

      if(--conn->async.num_pending > 0) {

        /* We are not done yet. Clean up and return.

	   This function will be called again. */

        if(conn->async.temp_ai)

          Curl_freeaddrinfo(conn->async.temp_ai);

        return CURLE_OUT_OF_MEMORY;

      }

#endif

      rc = CURLE_OUT_OF_MEMORY;

    }

  }

#if defined(ENABLE_IPV6) && defined(CURLRES_ARES) /* CURLRES_IPV6 */

  else

  {

      if(--conn->async.num_pending > 0)

        /* We are not done yet. Just return. */

        return CURLE_OK;



      if(conn->async.temp_ai) {

        /* We are done, and while this latest request

           failed, some previous results exist. */

        struct SessionHandle *data = conn->data;



        if(data->share)

          Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);



        dns = Curl_cache_addr(data, conn->async.temp_ai,

                              conn->async.hostname,

                              conn->async.port);

        if(!dns) {

          /* failed to store, cleanup and return error */

          Curl_freeaddrinfo(conn->async.temp_ai);

          rc = CURLE_OUT_OF_MEMORY;

        }



        if(data->share)

          Curl_share_unlock(data, CURL_LOCK_DATA_DNS);

      }

  }

#endif



  conn->async.dns = dns;



 /* Set async.done TRUE last in this function since it may be used multi-

lib/urldata.h

+2 −0
Original line number Diff line number Diff line
@@ -479,6 +479,8 @@ struct Curl_async { 
  bool done;  /* set TRUE when the lookup is complete */

  int status; /* if done is TRUE, this is the status from the callback */

  void *os_specific;  /* 'struct thread_data' for Windows */

  int num_pending; /* number of ares_gethostbyname() requests */

  Curl_addrinfo *temp_ai; /* intermediary result while fetching c-ares parts */

};

#endif