diff options
| author | Lucas Clemente Vella <lvella@gmail.com> | 2021-04-24 20:04:53 +0100 |
|---|---|---|
| committer | Daniel Stenberg <daniel@haxx.se> | 2021-05-20 16:58:31 +0200 |
| commit | 84d2839740ca78041ac7419d9aaeac55c1e1c729 (patch) | |
| tree | aee6202a7815b0cce0e1a2b9179c3b4421e7fb9a /docs/libcurl/opts | |
| parent | ac54b10933749d4c17d9568532ff2f1ed64c119a (diff) | |
| download | curl-84d2839740ca78041ac7419d9aaeac55c1e1c729.tar.gz | |
CURLOPT_IPRESOLVE: preventing wrong IP version from being used
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
Diffstat (limited to 'docs/libcurl/opts')
| -rw-r--r-- | docs/libcurl/opts/CURLOPT_IPRESOLVE.3 | 13 | ||||
| -rw-r--r-- | docs/libcurl/opts/CURLOPT_RESOLVE.3 | 4 |
2 files changed, 9 insertions, 8 deletions
diff --git a/docs/libcurl/opts/CURLOPT_IPRESOLVE.3 b/docs/libcurl/opts/CURLOPT_IPRESOLVE.3 index 4bdd8b2fe..6d534da9e 100644 --- a/docs/libcurl/opts/CURLOPT_IPRESOLVE.3 +++ b/docs/libcurl/opts/CURLOPT_IPRESOLVE.3 @@ -29,14 +29,15 @@ CURLOPT_IPRESOLVE \- specify which IP protocol version to use CURLcode curl_easy_setopt(CURL *handle, CURLOPT_IPRESOLVE, long resolve); .SH DESCRIPTION Allows an application to select what kind of IP addresses to use when -resolving host names. This is only interesting when using host names that -resolve addresses using more than one version of IP. The allowed values are: +establishing a connection or choosing one from the connection pool. This is +interesting when using host names that resolve addresses using more than +one version of IP. The allowed values are: .IP CURL_IPRESOLVE_WHATEVER -Default, resolves addresses to all IP versions that your system allows. +Default, can use addresses of all IP versions that your system allows. .IP CURL_IPRESOLVE_V4 -Resolve to IPv4 addresses. +Uses only IPv4 addresses. .IP CURL_IPRESOLVE_V6 -Resolve to IPv6 addresses. +Uses only IPv6 addresses. .SH DEFAULT CURL_IPRESOLVE_WHATEVER .SH PROTOCOLS @@ -47,7 +48,7 @@ CURL *curl = curl_easy_init(); if(curl) { curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin"); - /* resolve host name using IPv6-names only */ + /* of all addresses example.com resolves to, only IPv6 ones are used */ curl_easy_setopt(curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V6); ret = curl_easy_perform(curl); diff --git a/docs/libcurl/opts/CURLOPT_RESOLVE.3 b/docs/libcurl/opts/CURLOPT_RESOLVE.3 index 20ee69b0c..57a5401e4 100644 --- a/docs/libcurl/opts/CURLOPT_RESOLVE.3 +++ b/docs/libcurl/opts/CURLOPT_RESOLVE.3 @@ -57,8 +57,8 @@ 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. -The provided ADDRESS set by this option will be used even if -\fICURLOPT_IPRESOLVE(3)\fP is set to make libcurl use another IP version. +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 |