commit dc9b69d5331dcdca4547c0490cb9fefbd89e40f6
Author: Florian Weimer <fweimer@redhat.com>
Date: Fri Dec 17 12:01:20 2021 +0100
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>
(cherry picked from commit b99b0f93ee8762fe53ff65802deb6f00700b9924)
diff --git a/manual/nss.texi b/manual/nss.texi
index 3aaa7786f8cf3168..524d22ad1e7f8ca0 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 f1c97f7c8e9d7378..dbc87868dd408d9f 100644
--- a/nss/XXX-lookup.c
+++ b/nss/XXX-lookup.c
@@ -29,7 +29,7 @@
|* 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 ab121cb371c087e9..54561f03287db2e4 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: