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| author | Florian Weimer <fweimer@redhat.com> | 2021-12-17 12:01:20 +0100 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2021-12-17 12:01:25 +0100 |
| commit | b99b0f93ee8762fe53ff65802deb6f00700b9924 (patch) | |
| tree | e8d5ed3899507030413f48489daee39aead1b713 | |
| parent | ce1e5b11229f19820b86f8b19d651f16009552b0 (diff) | |
| download | glibc-b99b0f93ee8762fe53ff65802deb6f00700b9924.zip glibc-b99b0f93ee8762fe53ff65802deb6f00700b9924.tar.gz glibc-b99b0f93ee8762fe53ff65802deb6f00700b9924.tar.bz2 | |
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>
| -rw-r--r-- | manual/nss.texi | 5 | ||||
| -rw-r--r-- | nss/XXX-lookup.c | 2 | ||||
| -rw-r--r-- | 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: |