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From b99b0f93ee8762fe53ff65802deb6f00700b9924 Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Fri, 17 Dec 2021 12:01:20 +0100
Subject: [PATCH] nss: Use "files dns" as the default for the hosts database
(bug 28700)
This matches what is currently in nss/nsswitch.conf. The new ordering
matches what most distributions use in their installed configuration
files.
It is common to add localhost to /etc/hosts because the name does not
exist in the DNS, but is commonly used as a host name.
With the built-in "dns [!UNAVAIL=return] files" default, dns is
searched first and provides an answer for "localhost" (NXDOMAIN).
We never look at the files database as a result, so the contents of
/etc/hosts is ignored. This means that "getent hosts localhost"
fail without a /etc/nsswitch.conf file, even though the host name
is listed in /etc/hosts.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
---
manual/nss.texi | 5 ++---
nss/XXX-lookup.c | 2 +-
nss/nss_database.c | 4 ++--
3 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/manual/nss.texi b/manual/nss.texi
index 3aaa778..524d22a 100644
--- a/manual/nss.texi
+++ b/manual/nss.texi
@@ -324,9 +324,8 @@ missing.
@cindex default value, and NSS
For the @code{hosts} and @code{networks} databases the default value is
-@code{dns [!UNAVAIL=return] files}. I.e., the system is prepared for
-the DNS service not to be available but if it is available the answer it
-returns is definitive.
+@code{files dns}. I.e., local configuration will override the contents
+of the domain name system (DNS).
The @code{passwd}, @code{group}, and @code{shadow} databases was
traditionally handled in a special way. The appropriate files in the
diff --git a/nss/XXX-lookup.c b/nss/XXX-lookup.c
index 302c636..e129f69 100644
--- a/nss/XXX-lookup.c
+++ b/nss/XXX-lookup.c
@@ -28,7 +28,7 @@
|* ALTERNATE_NAME - name of another service which is examined in *|
|* case DATABASE_NAME is not found *|
|* *|
-|* DEFAULT_CONFIG - string for default conf (e.g. "dns files") *|
+|* DEFAULT_CONFIG - string for default conf (e.g. "files dns") *|
|* *|
\*******************************************************************/
diff --git a/nss/nss_database.c b/nss/nss_database.c
index ab121cb..54561f0 100644
--- a/nss/nss_database.c
+++ b/nss/nss_database.c
@@ -80,7 +80,7 @@ enum nss_database_default
{
nss_database_default_defconfig = 0, /* "nis [NOTFOUND=return] files". */
nss_database_default_compat, /* "compat [NOTFOUND=return] files". */
- nss_database_default_dns, /* "dns [!UNAVAIL=return] files". */
+ nss_database_default_dns, /* "files dns". */
nss_database_default_files, /* "files". */
nss_database_default_nis, /* "nis". */
nss_database_default_nis_nisplus, /* "nis nisplus". */
@@ -133,7 +133,7 @@ nss_database_select_default (struct nss_database_default_cache *cache,
#endif
case nss_database_default_dns:
- line = "dns [!UNAVAIL=return] files";
+ line = "files dns";
break;
case nss_database_default_files:
--
1.8.3.1
|
