92 lines
3.5 KiB
Groff
92 lines
3.5 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_ALTSVC_CTRL 3 "5 Feb 2019" libcurl libcurl
|
|
.SH NAME
|
|
CURLOPT_ALTSVC_CTRL \- control alt-svc behavior
|
|
.SH SYNOPSIS
|
|
.nf
|
|
#include <curl/curl.h>
|
|
|
|
#define CURLALTSVC_READONLYFILE (1<<2)
|
|
#define CURLALTSVC_H1 (1<<3)
|
|
#define CURLALTSVC_H2 (1<<4)
|
|
#define CURLALTSVC_H3 (1<<5)
|
|
|
|
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ALTSVC_CTRL, long bitmask);
|
|
.fi
|
|
.SH DESCRIPTION
|
|
Populate the long \fIbitmask\fP with the correct set of features to instruct
|
|
libcurl how to handle Alt-Svc for the transfers using this handle.
|
|
|
|
libcurl only accepts Alt-Svc headers over a secure transport, meaning
|
|
HTTPS. It also only completes a request to an alternative origin if that
|
|
origin is properly hosted over HTTPS. These requirements are there to make
|
|
sure both the source and the destination are legitimate.
|
|
|
|
Alternative services are only used when setting up new connections. If there
|
|
exists an existing connection to the host in the connection pool, then that is
|
|
preferred.
|
|
|
|
Setting any bit enables the alt-svc engine.
|
|
.IP "CURLALTSVC_READONLYFILE"
|
|
Do not write the alt-svc cache back to the file specified with
|
|
\fICURLOPT_ALTSVC(3)\fP even if it gets updated. By default a file specified
|
|
with that option is read and written to as deemed necessary.
|
|
.IP "CURLALTSVC_H1"
|
|
Accept alternative services offered over HTTP/1.1.
|
|
.IP "CURLALTSVC_H2"
|
|
Accept alternative services offered over HTTP/2. This is only used if libcurl
|
|
was also built to actually support HTTP/2, otherwise this bit is ignored.
|
|
.IP "CURLALTSVC_H3"
|
|
Accept alternative services offered over HTTP/3. This is only used if libcurl
|
|
was also built to actually support HTTP/3, otherwise this bit is ignored.
|
|
.SH DEFAULT
|
|
Alt-Svc handling is disabled by default. If \fICURLOPT_ALTSVC(3)\fP is set,
|
|
\fICURLOPT_ALTSVC_CTRL(3)\fP has a default value corresponding to
|
|
CURLALTSVC_H1 | CURLALTSVC_H2 | CURLALTSVC_H3 - the HTTP/2 and HTTP/3 bits are
|
|
only set if libcurl was built with support for those versions.
|
|
.SH PROTOCOLS
|
|
HTTPS
|
|
.SH EXAMPLE
|
|
.nf
|
|
int main(void)
|
|
{
|
|
CURL *curl = curl_easy_init();
|
|
if(curl) {
|
|
curl_easy_setopt(curl, CURLOPT_ALTSVC_CTRL, (long)CURLALTSVC_H1);
|
|
curl_easy_setopt(curl, CURLOPT_ALTSVC, "altsvc-cache.txt");
|
|
curl_easy_perform(curl);
|
|
}
|
|
}
|
|
.fi
|
|
.SH AVAILABILITY
|
|
Added in 7.64.1
|
|
.SH RETURN VALUE
|
|
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
|
|
.SH "SEE ALSO"
|
|
.BR CURLOPT_ALTSVC (3),
|
|
.BR CURLOPT_CONNECT_TO (3),
|
|
.BR CURLOPT_RESOLVE (3)
|