Commit 82245eaa authored by Isaac Boukris's avatar Isaac Boukris Committed by Michael Kaufmann
Browse files

Curl_getconnectinfo: avoid checking if the connection is closed 

It doesn't benefit us much as the connection could get closed at
any time, and also by checking we lose the ability to determine
if the socket was closed by reading zero bytes.

Reported-by: Michael Kaufmann

Closes https://github.com/curl/curl/pull/1134
parent 6bc10516

lib/connect.c

+27 −18
Original line number Diff line number Diff line
@@ -1247,29 +1247,38 @@ curl_socket_t Curl_getconnectinfo(struct Curl_easy *data, 
      /* only store this if the caller cares for it */

      *connp = c;

    sockfd = c->sock[FIRSTSOCKET];

    /* we have a socket connected, let's determine if the server shut down */

    /* determine if ssl */

    if(c->ssl[FIRSTSOCKET].use) {

  }

  else

    return CURL_SOCKET_BAD;



  return sockfd;

}



/*

 * Check if a connection seems to be alive.

 */

bool Curl_connalive(struct connectdata *conn)

{

  /* First determine if ssl */

  if(conn->ssl[FIRSTSOCKET].use) {

    /* use the SSL context */

      if(!Curl_ssl_check_cxn(c))

        return CURL_SOCKET_BAD;   /* FIN received */

    if(!Curl_ssl_check_cxn(conn))

      return false;   /* FIN received */

  }

/* Minix 3.1 doesn't support any flags on recv; just assume socket is OK */

#ifdef MSG_PEEK

    else if(sockfd != CURL_SOCKET_BAD) {

  else if(conn->sock[FIRSTSOCKET] == CURL_SOCKET_BAD)

    return false;

  else {

    /* use the socket */

    char buf;

      if(recv((RECV_TYPE_ARG1)sockfd, (RECV_TYPE_ARG2)&buf,

    if(recv((RECV_TYPE_ARG1)conn->sock[FIRSTSOCKET], (RECV_TYPE_ARG2)&buf,

            (RECV_TYPE_ARG3)1, (RECV_TYPE_ARG4)MSG_PEEK) == 0) {

        return CURL_SOCKET_BAD;   /* FIN received */

      return false;   /* FIN received */

    }

  }

#endif

  }

  else

    return CURL_SOCKET_BAD;



  return sockfd;

  return true;

}



/*

lib/connect.h

+5 −0
Original line number Diff line number Diff line
@@ -52,6 +52,11 @@ time_t Curl_timeleft(struct Curl_easy *data, 
curl_socket_t Curl_getconnectinfo(struct Curl_easy *data,

                                  struct connectdata **connp);



/*

 * Check if a connection seems to be alive.

 */

bool Curl_connalive(struct connectdata *conn);



#ifdef USE_WINSOCK

/* When you run a program that uses the Windows Sockets API, you may

   experience slow performance when you copy data to a TCP server.

lib/rtsp.c

+4 −7
Original line number Diff line number Diff line
@@ -140,7 +140,7 @@ static CURLcode rtsp_setup_connection(struct connectdata *conn) 
 * want to block the application forever while receiving a stream. Therefore,

 * we cannot assume that an RTSP socket is dead just because it is readable.

 *

 * Instead, if it is readable, run Curl_getconnectinfo() to peek at the socket

 * Instead, if it is readable, run Curl_connalive() to peek at the socket

 * and distinguish between closed and data.

 */

bool Curl_rtsp_connisdead(struct connectdata *check)
@@ -157,12 +157,9 @@ bool Curl_rtsp_connisdead(struct connectdata *check) 
    /* socket is in an error state */

    ret_val = TRUE;

  }

  else if((sval & CURL_CSELECT_IN) && check->data) {

    /* readable with no error. could be closed or could be alive but we can

       only check if we have a proper Curl_easy for the connection */

    curl_socket_t connectinfo = Curl_getconnectinfo(check->data, &check);

    if(connectinfo != CURL_SOCKET_BAD)

      ret_val = FALSE;

  else if(sval & CURL_CSELECT_IN) {

    /* readable with no error. could still be closed */

    ret_val = !Curl_connalive(check);

  }



  return ret_val;