mirror of
https://github.com/curl/curl.git
synced 2024-12-15 06:40:09 +08:00
84d2839740
In some situations, it was possible that a transfer was setup to use an specific IP version, but due do DNS caching or connection reuse, it ended up using a different IP version from requested. This commit changes the effect of CURLOPT_IPRESOLVE from simply restricting address resolution to preventing the wrong connection type being used, when choosing a connection from the pool, and to restricting what addresses could be used when establishing a new connection. It is important that all addresses versions are resolved, even if not used in that transfer in particular, because the result is cached, and could be useful for a different transfer with a different CURLOPT_IPRESOLVE setting. Closes #6853
103 lines
4.1 KiB
Groff
103 lines
4.1 KiB
Groff
.\" **************************************************************************
|
|
.\" * _ _ ____ _
|
|
.\" * Project ___| | | | _ \| |
|
|
.\" * / __| | | | |_) | |
|
|
.\" * | (__| |_| | _ <| |___
|
|
.\" * \___|\___/|_| \_\_____|
|
|
.\" *
|
|
.\" * Copyright (C) 1998 - 2021, 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.
|
|
.\" *
|
|
.\" **************************************************************************
|
|
.\"
|
|
.TH CURLOPT_RESOLVE 3 "19 Jun 2014" "libcurl 7.37.0" "curl_easy_setopt options"
|
|
.SH NAME
|
|
CURLOPT_RESOLVE \- provide custom host name to IP address resolves
|
|
.SH SYNOPSIS
|
|
.nf
|
|
#include <curl/curl.h>
|
|
|
|
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_RESOLVE,
|
|
struct curl_slist *hosts);
|
|
.SH DESCRIPTION
|
|
Pass a pointer to a linked list of strings with host name resolve information
|
|
to use for requests with this handle. The linked list should be a fully valid
|
|
list of \fBstruct curl_slist\fP structs properly filled in. Use
|
|
\fIcurl_slist_append(3)\fP to create the list and \fIcurl_slist_free_all(3)\fP
|
|
to clean up an entire list.
|
|
|
|
Each single name resolve string should be written using the format
|
|
[+]HOST:PORT:ADDRESS[,ADDRESS]... where HOST is the name libcurl will try
|
|
to resolve, PORT is the port number of the service where libcurl wants
|
|
to connect to the HOST and ADDRESS is one or more numerical IP
|
|
addresses. If you specify multiple ip addresses they need to be
|
|
separated by comma. If libcurl is built to support IPv6, each of the
|
|
ADDRESS entries can of course be either IPv4 or IPv6 style addressing.
|
|
|
|
This option effectively pre-populates the DNS cache with entries for the
|
|
host+port pair so redirects and everything that operations against the
|
|
HOST+PORT will instead use your provided ADDRESS.
|
|
|
|
The optional leading "+" signifies whether the new entry should time-out or
|
|
not. Entries added with "HOST:..." will never time-out whereas entries added
|
|
with "+HOST:..." will time-out just like ordinary DNS cache entries.
|
|
|
|
If the DNS cache already has an entry for the given host+port pair, then
|
|
this entry will be removed and a new entry will be created. This is because
|
|
the old entry may have have different addresses or a different time-out
|
|
setting.
|
|
|
|
An ADDRESS provided by this option will only be use if not restricted by
|
|
the setting of \fICURLOPT_IPRESOLVE(3)\fP to a different IP version.
|
|
|
|
Remove names from the DNS cache again, to stop providing these fake resolves,
|
|
by including a string in the linked list that uses the format
|
|
\&"-HOST:PORT". The host name must be prefixed with a dash, and the host name
|
|
and port number must exactly match what was already added previously.
|
|
|
|
Support for providing the ADDRESS within [brackets] was added in 7.57.0.
|
|
|
|
Support for providing multiple IP addresses per entry was added in 7.59.0.
|
|
|
|
Support for adding non-permanent entries by using the "+" prefix was added in
|
|
7.75.0.
|
|
.SH DEFAULT
|
|
NULL
|
|
.SH PROTOCOLS
|
|
All
|
|
.SH EXAMPLE
|
|
.nf
|
|
CURL *curl;
|
|
struct curl_slist *host = NULL;
|
|
host = curl_slist_append(NULL, "example.com:80:127.0.0.1");
|
|
|
|
curl = curl_easy_init();
|
|
if(curl) {
|
|
curl_easy_setopt(curl, CURLOPT_RESOLVE, host);
|
|
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
|
|
|
|
curl_easy_perform(curl);
|
|
|
|
/* always cleanup */
|
|
curl_easy_cleanup(curl);
|
|
}
|
|
|
|
curl_slist_free_all(host);
|
|
.fi
|
|
.SH AVAILABILITY
|
|
Added in 7.21.3. Removal support added in 7.42.0.
|
|
.SH RETURN VALUE
|
|
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
|
|
.SH "SEE ALSO"
|
|
.BR CURLOPT_IPRESOLVE "(3), " CURLOPT_DNS_CACHE_TIMEOUT "(3), " CURLOPT_CONNECT_TO "(3), "
|