NAME

CURLOPT_OPENSOCKETDATA - pointer passed to open socket callback

SYNOPSIS

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_OPENSOCKETDATA, void *pointer);

DESCRIPTION

Pass a pointer that is untouched by libcurl and passed as the first argument in the open socket callback set with CURLOPT_OPENSOCKETFUNCTION(3).

DEFAULT

The default value of this parameter is NULL.

PROTOCOLS

All

EXAMPLE

/* make libcurl use the already established socket 'sockfd' */
static curl_socket_t opensocket(void *clientp,


                                curlsocktype purpose,


                                struct curl_sockaddr *address)
{


  curl_socket_t sockfd;


  sockfd = *(curl_socket_t *)clientp;


  /* the actual externally set socket is passed in via the OPENSOCKETDATA


     option */


  return sockfd;
}
static int sockopt_callback(void *clientp, curl_socket_t curlfd,


                            curlsocktype purpose)
{


  /* This return code was added in libcurl 7.21.5 */


  return CURL_SOCKOPT_ALREADY_CONNECTED;
}
int main(void)
{


  CURL *curl = curl_easy_init();


  if(curl) {


    CURLcode res;


    extern int sockfd; /* the already connected one */


    /* libcurl thinks that you connect to the host


     * and port that you specify in the URL option. */


    curl_easy_setopt(curl, CURLOPT_URL, "http://99.99.99.99:9999");


    /* call this function to get a socket */


    curl_easy_setopt(curl, CURLOPT_OPENSOCKETFUNCTION, opensocket);


    curl_easy_setopt(curl, CURLOPT_OPENSOCKETDATA, &sockfd);


    /* call this function to set options for the socket */


    curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);


    res = curl_easy_perform(curl);


    curl_easy_cleanup(curl);


  }
}

AVAILABILITY

Added in 7.17.1

RETURN VALUE

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.