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Merge branch 'dns_resolver-docs-formatting-cleanup'

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Bagas Sanjaya says:

====================
dns_resolver docs formatting cleanup

Here are reST cleanups for DNS Resolver Module documentation.
====================

Link: https://patch.msgid.link/20250924020626.17073-1-bagasdotme@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski 2025-09-26 15:21:40 -07:00
commit 793adf57e2
1 changed files with 25 additions and 27 deletions
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52
Documentation/networking/dns_resolver.rst
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@ -25,11 +25,11 @@ These routines must be supported by userspace tools dns.upcall, cifs.upcall and
request-key. It is under development and does not yet provide the full feature
set. The features it does support include:
(*) Implements the dns_resolver key_type to contact userspace.
* Implements the dns_resolver key_type to contact userspace.
It does not yet support the following AFS features:
(*) Dns query support for AFSDB resource record.
* DNS query support for AFSDB resource record.
This code is extracted from the CIFS filesystem.
@ -64,44 +64,42 @@ before the more general line given above as the first match is the one taken::
Usage
=====
To make use of this facility, one of the following functions that are
implemented in the module can be called after doing::
To make use of this facility, first ``dns_resolver.h`` must be included::
#include <linux/dns_resolver.h>
::
Then queries may be made by calling::
int dns_query(const char *type, const char *name, size_t namelen,
const char *options, char **_result, time_t *_expiry);
This is the basic access function. It looks for a cached DNS query and if
it doesn't find it, it upcalls to userspace to make a new DNS query, which
may then be cached. The key description is constructed as a string of the
form::
This is the basic access function. It looks for a cached DNS query and if
it doesn't find it, it upcalls to userspace to make a new DNS query, which
may then be cached. The key description is constructed as a string of the
form::
[<type>:]<name>
where <type> optionally specifies the particular upcall program to invoke,
and thus the type of query to do, and <name> specifies the string to be
looked up. The default query type is a straight hostname to IP address
set lookup.
where <type> optionally specifies the particular upcall program to invoke,
and thus the type of query, and <name> specifies the string to be looked up.
The default query type is a straight hostname to IP address set lookup.
The name parameter is not required to be a NUL-terminated string, and its
length should be given by the namelen argument.
The name parameter is not required to be a NUL-terminated string, and its
length should be given by the namelen argument.
The options parameter may be NULL or it may be a set of options
appropriate to the query type.
The options parameter may be NULL or it may be a set of options
appropriate to the query type.
The return value is a string appropriate to the query type. For instance,
for the default query type it is just a list of comma-separated IPv4 and
IPv6 addresses. The caller must free the result.
The return value is a string appropriate to the query type. For instance,
for the default query type it is just a list of comma-separated IPv4 and
IPv6 addresses. The caller must free the result.
The length of the result string is returned on success, and a negative
error code is returned otherwise. -EKEYREJECTED will be returned if the
DNS lookup failed.
The length of the result string is returned on success, and a negative
error code is returned otherwise. -EKEYREJECTED will be returned if the
DNS lookup failed.
If _expiry is non-NULL, the expiry time (TTL) of the result will be
returned also.
If _expiry is non-NULL, the expiry time (TTL) of the result will be
returned also.
The kernel maintains an internal keyring in which it caches looked up keys.
This can be cleared by any process that has the CAP_SYS_ADMIN capability by
@ -142,8 +140,8 @@ the key will be discarded and recreated when the data it holds has expired.
dns_query() returns a copy of the value attached to the key, or an error if
that is indicated instead.
See <file:Documentation/security/keys/request-key.rst> for further
information about request-key function.
See Documentation/security/keys/request-key.rst for further information about
request-key function.
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