mirror of
https://github.com/curl/curl.git
synced 2024-12-27 06:59:43 +08:00
5b060a4108
... instead of using future tense. + numerous cleanups and improvements + stick to "reuse" not "re-use" + fewer contractions Closes #11713
128 lines
4.7 KiB
Groff
128 lines
4.7 KiB
Groff
.\" **************************************************************************
|
|
.\" * _ _ ____ _
|
|
.\" * Project ___| | | | _ \| |
|
|
.\" * / __| | | | |_) | |
|
|
.\" * | (__| |_| | _ <| |___
|
|
.\" * \___|\___/|_| \_\_____|
|
|
.\" *
|
|
.\" * Copyright (C) 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.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.
|
|
.\" *
|
|
.\" * SPDX-License-Identifier: curl
|
|
.\" *
|
|
.\" **************************************************************************
|
|
.\"
|
|
.TH CURLOPT_OPENSOCKETFUNCTION 3 "16 Jun 2014" libcurl libcurl
|
|
.SH NAME
|
|
CURLOPT_OPENSOCKETFUNCTION \- callback for opening socket
|
|
.SH SYNOPSIS
|
|
.nf
|
|
#include <curl/curl.h>
|
|
|
|
typedef enum {
|
|
CURLSOCKTYPE_IPCXN, /* socket created for a specific IP connection */
|
|
} curlsocktype;
|
|
|
|
struct curl_sockaddr {
|
|
int family;
|
|
int socktype;
|
|
int protocol;
|
|
unsigned int addrlen;
|
|
struct sockaddr addr;
|
|
};
|
|
|
|
curl_socket_t opensocket_callback(void *clientp,
|
|
curlsocktype purpose,
|
|
struct curl_sockaddr *address);
|
|
|
|
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_OPENSOCKETFUNCTION, opensocket_callback);
|
|
.SH DESCRIPTION
|
|
Pass a pointer to your callback function, which should match the prototype
|
|
shown above.
|
|
|
|
This callback function gets called by libcurl instead of the \fIsocket(2)\fP
|
|
call. The callback's \fIpurpose\fP argument identifies the exact purpose for
|
|
this particular socket. \fICURLSOCKTYPE_IPCXN\fP is for IP based connections
|
|
and is the only purpose currently used in libcurl. Future versions of libcurl
|
|
may support more purposes.
|
|
|
|
The \fIclientp\fP pointer contains whatever user-defined value set using the
|
|
\fICURLOPT_OPENSOCKETDATA(3)\fP function.
|
|
|
|
The callback gets the resolved peer address as the \fIaddress\fP argument and
|
|
is allowed to modify the address or refuse to connect completely. The callback
|
|
function should return the newly created socket or \fICURL_SOCKET_BAD\fP in
|
|
case no connection could be established or another error was detected. Any
|
|
additional \fIsetsockopt(2)\fP calls can of course be done on the socket at
|
|
the user's discretion. A \fICURL_SOCKET_BAD\fP return value from the callback
|
|
function signals an unrecoverable error to libcurl and it returns
|
|
\fICURLE_COULDNT_CONNECT\fP from the function that triggered this callback.
|
|
This return code can be used for IP address block listing.
|
|
|
|
If you want to pass in a socket with an already established connection, pass
|
|
the socket back with this callback and then use
|
|
\fICURLOPT_SOCKOPTFUNCTION(3)\fP to signal that it already is connected.
|
|
.SH DEFAULT
|
|
The default behavior is the equivalent of this:
|
|
.nf
|
|
return socket(addr->family, addr->socktype, addr->protocol);
|
|
.fi
|
|
.SH PROTOCOLS
|
|
All
|
|
.SH EXAMPLE
|
|
.nf
|
|
/* 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;
|
|
}
|
|
|
|
curl = curl_easy_init();
|
|
if(curl) {
|
|
/* 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);
|
|
}
|
|
.fi
|
|
.SH AVAILABILITY
|
|
Added in 7.17.1.
|
|
.SH RETURN VALUE
|
|
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
|
|
.SH "SEE ALSO"
|
|
.BR CURLOPT_OPENSOCKETDATA "(3), " CURLOPT_SOCKOPTFUNCTION "(3), "
|
|
.BR CURLOPT_CLOSESOCKETFUNCTION "(3), "
|