Commit b998d95b authored by Daniel Stenberg's avatar Daniel Stenberg
Browse files

FTP: fix proxy connect race condition 

When using the multi interface, a SOCKS proxy, and a connection that
wouldn't immediately consider itself connected (which my Linux tests do
by default), libcurl would be tricked into doing _two_ connects to the
SOCKS proxy when it setup the data connection and then of course the
second attempt would fail miserably and cause error.

This problem is a regression that was introduced by commit
4a42e5cd that was introduced in the 7.21.7 release.

Bug: http://curl.haxx.se/mail/lib-2011-08/0199.html
Reported by: Fabian Keil
parent d4489650

lib/connect.c

+2 −2
Original line number Diff line number Diff line
@@ -659,7 +659,7 @@ CURLcode Curl_is_connected(struct connectdata *conn, 


  *connected = FALSE; /* a very negative world view is best */



  if(conn->bits.tcpconnect) {

  if(conn->bits.tcpconnect[sockindex]) {

    /* we are connected already! */

    *connected = TRUE;

    return CURLE_OK;
@@ -698,7 +698,7 @@ CURLcode Curl_is_connected(struct connectdata *conn, 
      if(code)

        return code;



      conn->bits.tcpconnect = TRUE;

      conn->bits.tcpconnect[sockindex] = TRUE;

      *connected = TRUE;

      Curl_pgrsTime(data, TIMER_CONNECT); /* connect done */

      Curl_verboseconnect(conn);

lib/ftp.c

+8 −4
Original line number Diff line number Diff line
@@ -1043,7 +1043,7 @@ static CURLcode ftp_state_use_port(struct connectdata *conn, 
     The *proper* fix is to make sure that the active connection from the

     server is done in a non-blocking way. Currently, it is still BLOCKING.

  */

  conn->bits.tcpconnect = TRUE;

  conn->bits.tcpconnect[SECONDARYSOCKET] = TRUE;



  state(conn, FTP_PORT);

  return result;
@@ -1703,7 +1703,7 @@ static CURLcode ftp_state_pasv_resp(struct connectdata *conn, 
  if(result)

    return result;



  conn->bits.tcpconnect = connected; /* simply TRUE or FALSE */

  conn->bits.tcpconnect[SECONDARYSOCKET] = connected;



  /*

   * When this is used from the multi interface, this might've returned with
@@ -1741,6 +1741,9 @@ static CURLcode ftp_state_pasv_resp(struct connectdata *conn, 
    break;

  }



  if(result)

    return result;



  if(conn->bits.tunnel_proxy && conn->bits.httpproxy) {

    /* FIX: this MUST wait for a proper connect first if 'connected' is

     * FALSE */
@@ -1763,10 +1766,11 @@ static CURLcode ftp_state_pasv_resp(struct connectdata *conn, 


    data->state.proto.ftp = ftp_save;



    if(CURLE_OK != result)

    if(result)

      return result;

  }



  conn->bits.tcpconnect[SECONDARYSOCKET] = TRUE;



  state(conn, FTP_STOP); /* this phase is completed */
@@ -3473,7 +3477,7 @@ CURLcode ftp_perform(struct connectdata *conn, 
    result = ftp_easy_statemach(conn);

    *dophase_done = TRUE; /* with the easy interface we are done here */

  }

  *connected = conn->bits.tcpconnect;

  *connected = conn->bits.tcpconnect[FIRSTSOCKET];



  if(*dophase_done)

    DEBUGF(infof(conn->data, "DO phase is complete\n"));

lib/url.c

+10 −7
Original line number Diff line number Diff line
@@ -3200,8 +3200,11 @@ static CURLcode ConnectPlease(struct SessionHandle *data, 
    /* All is cool, we store the current information */

    conn->ip_addr = addr;



    if(*connected)

    if(*connected) {

      result = Curl_connected_proxy(conn);

      if(!result)

        conn->bits.tcpconnect[FIRSTSOCKET] = TRUE;

    }

  }



  if(result)
@@ -3294,7 +3297,7 @@ CURLcode Curl_protocol_connect(struct connectdata *conn, 


  *protocol_done = FALSE;



  if(conn->bits.tcpconnect && conn->bits.protoconnstart) {

  if(conn->bits.tcpconnect[FIRSTSOCKET] && conn->bits.protoconnstart) {

    /* We already are connected, get back. This may happen when the connect

       worked fine in the first call, like when we connect to a local server

       or proxy. Note that we don't know if the protocol is actually done.
@@ -3307,7 +3310,7 @@ CURLcode Curl_protocol_connect(struct connectdata *conn, 
    return CURLE_OK;

  }



  if(!conn->bits.tcpconnect) {

  if(!conn->bits.tcpconnect[FIRSTSOCKET]) {



    Curl_pgrsTime(data, TIMER_CONNECT); /* connect done */

    Curl_verboseconnect(conn);
@@ -4870,7 +4873,7 @@ static CURLcode create_conn(struct SessionHandle *data, 
    /* Setup a "faked" transfer that'll do nothing */

    if(CURLE_OK == result) {

      conn->data = data;

      conn->bits.tcpconnect = TRUE; /* we are "connected */

      conn->bits.tcpconnect[FIRSTSOCKET] = TRUE; /* we are "connected */



      ConnectionStore(data, conn);
@@ -5064,10 +5067,10 @@ CURLcode Curl_setup_conn(struct connectdata *conn, 
      if(connected) {

        result = Curl_protocol_connect(conn, protocol_done);

        if(CURLE_OK == result)

          conn->bits.tcpconnect = TRUE;

          conn->bits.tcpconnect[FIRSTSOCKET] = TRUE;

      }

      else

        conn->bits.tcpconnect = FALSE;

        conn->bits.tcpconnect[FIRSTSOCKET] = FALSE;



      /* if the connection was closed by the server while exchanging

         authentication informations, retry with the new set
@@ -5086,7 +5089,7 @@ CURLcode Curl_setup_conn(struct connectdata *conn, 
    else {

      Curl_pgrsTime(data, TIMER_CONNECT); /* we're connected already */

      Curl_pgrsTime(data, TIMER_APPCONNECT); /* we're connected already */

      conn->bits.tcpconnect = TRUE;

      conn->bits.tcpconnect[FIRSTSOCKET] = TRUE;

      *protocol_done = TRUE;

      Curl_verboseconnect(conn);

      Curl_updateconninfo(conn, conn->sock[FIRSTSOCKET]);

lib/urldata.h

+1 −1
Original line number Diff line number Diff line
@@ -411,7 +411,7 @@ struct ConnectBits { 
  bool do_more; /* this is set TRUE if the ->curl_do_more() function is

                   supposed to be called, after ->curl_do() */



  bool tcpconnect;    /* the TCP layer (or similar) is connected, this is set

  bool tcpconnect[2]; /* the TCP layer (or similar) is connected, this is set

                         the first time on the first connect function call */

  bool protoconnstart;/* the protocol layer has STARTED its operation after

                         the TCP layer connect */