Commit Graph

610 Commits

Author SHA1 Message Date
Paul Eggert
dff8da6b3e Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
Florian Weimer
61bac1a9d2 nss: Remove unused allocation from get_nscd_addresses in getaddrinfo
No bug because this is not visible if glibc is built with
optimization.  Otherwise this would be a critical resource leak.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-12-20 16:14:33 +01:00
Arjun Shankar
2f1c6652d7 Move getnameinfo from 'inet' to 'nss'
getnameinfo is an entry points for nss functionality.  This commit moves
it from the 'inet' subdirectory to 'nss'.  The corresponding Versions
entry is also moved from 'posix' into 'nss'.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:31:00 +02:00
Arjun Shankar
7f602256ab Move getaddrinfo from 'posix' into 'nss'
getaddrinfo is an entry point for nss functionality.  This commit moves
it from 'sysdeps/posix' to 'nss', gets rid of the stub in 'posix', and
moves all associated tests as well.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:31:00 +02:00
Arjun Shankar
1d74d2f042 Move 'services' routines from 'inet' into 'nss'
The getservby* and getservent* routines are entry points for nss
functionality.  This commit moves them from the 'inet' subdirectory to
'nss'.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:31:00 +02:00
Arjun Shankar
9b63a8ac40 Move 'rpc' routines from 'inet' into 'nss'
The getrpcby* and getrpcent* routines are entry points for nss
functionality.  This commit moves them from the 'inet' subdirectory to
'nss'.  The Versions entries for these routines along with a test,
located in the 'sunrpc' subdirectory, are also moved into 'nss'.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:31:00 +02:00
Arjun Shankar
a25a060c35 Move 'protocols' routines from 'inet' into 'nss'
The getprotoby* and getprotoent* routines are entry points for nss
functionality.  This commit moves them from the 'inet' subdirectory to
'nss'.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar
5a6e784e64 Move 'networks' routines from 'inet' into 'nss'
The getnetby* and getnetent* routines are entry points for nss
functionality.  This commit moves them from the 'inet' subdirectory to
'nss'.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar
3f7c7ac887 Move 'netgroup' routines from 'inet' into 'nss'
These netgroup routines are entry points for nss functionality.
This commit moves them along with netgroup.h from the 'inet'
subdirectory to 'nss', and adjusts any references accordingly.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar
a7e8d0b90b Move 'hosts' routines from 'inet' into 'nss'
The gethostby* and gethostent* routines are entry points for nss
functionality.  This commit moves them from the 'inet' subdirectory to
'nss'.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar
1c40266328 Move 'ethers' routines from 'inet' into 'nss'
ether_hostton and ether_ntohost are entry points for nss functionality.
This commit moves them from the 'inet' subdirectory to 'nss', and
adjusts any references accordingly.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar
4298586619 Move 'aliases' routines from 'inet' into 'nss'
The aliases routines are entry points for nss functionality.  This
commit moves aliases.h and the aliases routines from the 'inet'
subdirectory to 'nss', and adjusts any external references.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar
c6b577caef Remove 'shadow' and merge into 'nss'
The majority of shadow routines are entry points for nss functionality.
This commit removes the 'shadow' subdirectory and moves all
functionality and tests to 'nss'.  References to shadow/ are accordingly
changed.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar
0ac35d181e Remove 'pwd' and merge into 'nss'
The majority of pwd routines are entry points for nss functionality.
This commit removes the 'pwd' subdirectory and moves all functionality
and tests to 'nss'.  References to pwd/ are accordingly changed.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar
98b107e308 Remove 'gshadow' and merge into 'nss'
The majority of gshadow routines are entry points for nss functionality.
This commit removes the 'gshadow' subdirectory and moves all
functionality and tests to 'nss'.  References to gshadow/ are
accordingly changed.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Arjun Shankar
b121fdc552 Remove 'grp' and merge into 'nss' and 'posix'
The majority of grp routines are entry points for nss functionality.
This commit removes the 'grp' subdirectory and moves all nss-relevant
functionality and all tests to 'nss', and the 'setgroups' stub into
'posix' (alongside the 'getgroups' stub).  References to grp/ are
accordingly changed.  In addition, compat-initgroups.c, a fallback
implementation of initgroups is renamed to initgroups-fallback.c so that
the build system does not confuse it for nss_compat/compat-initgroups.c.

Build time improves very slightly; e.g. down from an average of 45.5s to
44.5s on an 8-thread mobile x86_64 CPU.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00
Joe Simmons-Talbott
820948edd9 nss: Get rid of alloca usage in makedb's write_output.
Replace alloca usage with a scratch_buffer.

Reviewed-by: Arjun Shankar <arjun@redhat.com>
2023-10-04 18:18:02 +00:00
Arjun Shankar
751850cf5a nss: Rearrange and sort Makefile variables
Rearrange lists of routines, tests, etc. into one-per-line in
nss/Makefile and sort them using scripts/sort-makefile-lines.py.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-10-04 12:09:18 +02:00
Romain Geissler
ec6b95c330 Fix leak in getaddrinfo introduced by the fix for CVE-2023-4806 [BZ #30843]
This patch fixes a very recently added leak in getaddrinfo.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-09-25 01:21:51 +01:00
Siddhesh Poyarekar
973fe93a56 getaddrinfo: Fix use after free in getcanonname (CVE-2023-4806)
When an NSS plugin only implements the _gethostbyname2_r and
_getcanonname_r callbacks, getaddrinfo could use memory that was freed
during tmpbuf resizing, through h_name in a previous query response.

The backing store for res->at->name when doing a query with
gethostbyname3_r or gethostbyname2_r is tmpbuf, which is reallocated in
gethosts during the query.  For AF_INET6 lookup with AI_ALL |
AI_V4MAPPED, gethosts gets called twice, once for a v6 lookup and second
for a v4 lookup.  In this case, if the first call reallocates tmpbuf
enough number of times, resulting in a malloc, th->h_name (that
res->at->name refers to) ends up on a heap allocated storage in tmpbuf.
Now if the second call to gethosts also causes the plugin callback to
return NSS_STATUS_TRYAGAIN, tmpbuf will get freed, resulting in a UAF
reference in res->at->name.  This then gets dereferenced in the
getcanonname_r plugin call, resulting in the use after free.

Fix this by copying h_name over and freeing it at the end.  This
resolves BZ #30843, which is assigned CVE-2023-4806.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-09-15 14:38:28 -04:00
Andreas Schwab
c437631485 Restore lookup of IPv4 mapped addresses in files database (bug 25457)
This was broken by commit 9c02d0784d ("nss_files: Remove RES_USE_INET6
from hosts processing"), which removed too much.
2023-07-24 13:16:24 +02:00
Frédéric Bérat
8022fc7d51 tests: replace system by xsystem
With fortification enabled, system calls return result needs to be checked,
has it gets the __wur macro enabled.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-06-19 09:15:05 -04:00
Frédéric Bérat
f6a532fbd0 tests: Replace various function calls with their x variant
With fortification enabled, few function calls return result need to be
checked, has they get the __wur macro enabled.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-06-06 08:23:53 -04:00
Paul Pluzhnikov
7f0d9e61f4 Fix all the remaining misspellings -- BZ 25337 2023-06-02 01:39:48 +00:00
Arjun Shankar
bea1a4a773 nss: Reconcile conditional declaration and use of `is_nscd'
This change harmonizes the declaration and use of `is_nscd' and fixes a
build failure with the "--enable-static-nss --enable-nscd"
configuration options due to `is_nscd' being used undeclared.

The purpose of `is_nscd' is to avoid (nss <-> nscd) recursion in
dynamically linked libc (SHARED) that is nscd-aware (USE_NSCD), and so
its declaration and use should be guarded by the definition of those
macros.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-05-16 11:40:10 +02:00
Adhemerval Zanella Netto
88677348b4 Move libc_freeres_ptrs and libc_subfreeres to hidden/weak functions
They are both used by __libc_freeres to free all library malloc
allocated resources to help tooling like mtrace or valgrind with
memory leak tracking.

The current scheme uses assembly markers and linker script entries
to consolidate the free routine function pointers in the RELRO segment
and to be freed buffers in BSS.

This patch changes it to use specific free functions for
libc_freeres_ptrs buffers and call the function pointer array directly
with call_function_static_weak.

It allows the removal of both the internal macros and the linker
script sections.

Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-03-27 13:57:55 -03:00
Qihao Chencao
cc4d6614b5 Use uintptr_t instead of performing pointer subtraction with a null pointer
Signed-off-by: Qihao Chencao <twose@qq.com>

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-02-17 17:07:44 -03:00
Wilco Dijkstra
32c7acd464 Replace rawmemchr (s, '\0') with strchr
Almost all uses of rawmemchr find the end of a string.  Since most targets use
a generic implementation, replacing it with strchr is better since that is
optimized by compilers into strlen (s) + s.  Also fix the generic rawmemchr
implementation to use a cast to unsigned char in the if statement.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-02-06 16:16:19 +00:00
Joseph Myers
ae612c45ef Update copyright dates not handled by scripts/update-copyrights
I've updated copyright dates in glibc for 2023.  This is the patch for
the changes not generated by scripts/update-copyrights and subsequent
build / regeneration of generated files.
2023-01-06 21:45:36 +00:00
Joseph Myers
6d7e8eda9b Update copyright dates with scripts/update-copyrights 2023-01-06 21:14:39 +00:00
Florian Weimer
58548b9d68 Use PTR_MANGLE and PTR_DEMANGLE unconditionally in C sources
In the future, this will result in a compilation failure if the
macros are unexpectedly undefined (due to header inclusion ordering
or header inclusion missing altogether).

Assembler sources are more difficult to convert.  In many cases,
they are hand-optimized for the mangling and no-mangling variants,
which is why they are not converted.

sysdeps/s390/s390-32/__longjmp.c and sysdeps/s390/s390-64/__longjmp.c
are special: These are C sources, but most of the implementation is
in assembler, so the PTR_DEMANGLE macro has to be undefined in some
cases, to match the assembler style.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-10-18 17:04:10 +02:00
Florian Weimer
88f4b6929c Introduce <pointer_guard.h>, extracted from <sysdep.h>
This allows us to define a generic no-op version of PTR_MANGLE and
PTR_DEMANGLE.  In the future, we can use PTR_MANGLE and PTR_DEMANGLE
unconditionally in C sources, avoiding an unintended loss of hardening
due to missing include files or unlucky header inclusion ordering.

In i386 and x86_64, we can avoid a <tls.h> dependency in the C
code by using the computed constant from <tcb-offsets.h>.  <sysdep.h>
no longer includes these definitions, so there is no cyclic dependency
anymore when computing the <tcb-offsets.h> constants.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-10-18 17:03:55 +02:00
Florian Weimer
c02e29a0ba nss: Use shared prefix in IPv4 address in tst-reload1
Otherwise, sorting based on the longest-matching prefix in
getaddrinfo can reorder the addresses in ways the test does not
expect, depending on the IPv4 address of the host.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-09-23 19:30:57 +02:00
Florian Weimer
fecf481f0f nss: Enhance tst-reload1 coverage and logging
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-09-23 19:30:57 +02:00
Florian Weimer
c75d20b5b2 nss: Fix tst-nss-files-hosts-long on single-stack hosts (bug 24816)
getent implicitly passes AI_ADDRCONFIG to getaddrinfo by default.
Use --no-addrconfig to suppress that, so that both IPv4 and IPv6
lookups succeed even if the address family is not supported by the
host.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-09-20 13:09:55 +02:00
Florian Weimer
a623f13adf nss: Implement --no-addrconfig option for getent
The ahosts, ahostsv4, ahostsv6 commands unconditionally pass
AI_ADDRCONFIG to getaddrinfo, which is not always desired.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-09-20 13:09:25 +02:00
Aurelien Jarno
f278835f59 makedb: fix build with libselinux >= 3.1 (Bug 26233)
glibc doesn't build with libselinux 3.1 that has been released recently
due to new deprecations introduced in that version and the fact that
glibc is built with -Werror by default:

| makedb.c: In function ‘set_file_creation_context’:
| makedb.c:849:3: error: ‘security_context_t’ is deprecated [-Werror=deprecated-declarations]
|   849 |   security_context_t ctx;
|       |   ^~~~~~~~~~~~~~~~~~
| makedb.c:863:3: error: ‘matchpathcon’ is deprecated: Use selabel_lookup instead [-Werror=deprecated-declarations]
|   863 |   if (matchpathcon (outname, S_IFREG | mode, &ctx) == 0 && ctx != NULL)
|       |   ^~
| In file included from makedb.c:50:
| /usr/include/selinux/selinux.h:500:12: note: declared here
|   500 | extern int matchpathcon(const char *path,
|       |            ^~~~~~~~~~~~
| cc1: all warnings being treated as errors

This patch fixes the makedb half of bug 26233 by moving to the new
SELinux APIs and removes the existing compiler pragmas as no longer
required. Upstream API usage feedback gathered by Arjun is integrated
into this version of the fix.

The built makedb was tested and operates as expected on x86_64 with
SELinu in enforcing mode.

No regressions on x86_64 with libselinux 3.3.

Co-authored-by: Arjun Shankar <arjun@redhat.com>
Co-authored-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-09-12 18:26:49 -04:00
Sam James
ace9e3edbc nss: handle stat failure in check_reload_and_get (BZ #28752)
Skip the chroot test if the database isn't loaded
correctly (because the chroot test uses some
existing DB state).

The __stat64_time64 -> fstatat call can fail if
running under an (aggressive) seccomp filter,
like Firefox seems to use.

This manifested in a crash when using glib built
with FAM support with such a Firefox build.

Suggested-by: DJ Delorie <dj@redhat.com>
Signed-off-by: Sam James <sam@gentoo.org>
Reviewed-by: DJ Delorie <dj@redhat.com>
2022-06-08 21:29:39 -04:00
Sam James
3fdf0a205b nss: add assert to DB_LOOKUP_FCT (BZ #28752)
It's interesting if we have a null action list,
so an assert is worthwhile.

Suggested-by: DJ Delorie <dj@redhat.com>
Signed-off-by: Sam James <sam@gentoo.org>
Reviewed-by: DJ Delorie <dj@redhat.com>
2022-06-08 21:29:39 -04:00
Noah Goldstein
3d155d4b6c nss: Optimize nss_hash in nss_hash.c
The prior unrolling didn't really do much as it left the dependency
chain between iterations. Unrolled the loop for 4 so 4x multiplies
could be pipelined in out-of-order machines.

Results for __nss_hash
Benchmarked on Tigerlake: 11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz

Time as Geometric Mean of N=25 runs
Geometric of all benchmark New / Old: 0.845
  type, length, New Time, Old Time, New Time / Old Time
 fixed,      0,    4.019,    3.729,               1.078
 fixed,      1,     4.95,    5.707,               0.867
 fixed,      2,    5.152,    5.657,               0.911
 fixed,      3,    4.641,    5.721,               0.811
 fixed,      4,    5.551,     5.81,               0.955
 fixed,      5,    6.525,    6.552,               0.996
 fixed,      6,    6.711,    6.561,               1.023
 fixed,      7,    6.715,    6.767,               0.992
 fixed,      8,    7.874,    7.915,               0.995
 fixed,      9,    8.888,    9.767,                0.91
 fixed,     10,    8.959,    9.762,               0.918
 fixed,     11,    9.188,    9.987,                0.92
 fixed,     12,    9.708,   10.618,               0.914
 fixed,     13,   10.393,    11.14,               0.933
 fixed,     14,   10.628,   12.097,               0.879
 fixed,     15,   10.982,   12.965,               0.847
 fixed,     16,   11.851,   14.429,               0.821
 fixed,     32,   24.334,   34.414,               0.707
 fixed,     64,   55.618,   86.688,               0.642
 fixed,    128,  118.261,   224.36,               0.527
 fixed,    256,  256.183,  538.629,               0.476
random,      2,   11.194,   11.556,               0.969
random,      4,   17.516,   17.205,               1.018
random,      8,   23.501,   20.985,                1.12
random,     16,   28.131,   29.212,               0.963
random,     32,   35.436,   38.662,               0.917
random,     64,    45.74,   58.868,               0.777
random,    128,   75.394,  121.963,               0.618
random,    256,  139.524,  260.726,               0.535
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-05-23 10:38:40 -05:00
Noah Goldstein
5f2f0f6977 nss: Add tests for the nss_hash in nss_hash.h
If we want to further optimize the function tests are needed.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-05-23 10:38:40 -05:00
Samuel Thibault
67ab66541d hurd: Fix arbitrary error code
ELIBBAD is Linux-specific.
2022-04-12 22:15:48 +02:00
DJ Delorie
2fe64148a8 Allow for unpriviledged nested containers
If the build itself is run in a container, we may not be able to
fully set up a nested container for test-container testing.
Notably is the mounting of /proc, since it's critical that it
be mounted from within the same PID namespace as its users, and
thus cannot be bind mounted from outside the container like other
mounts.

This patch defaults to using the parent's PID namespace instead of
creating a new one, as this is more likely to be allowed.

If the test needs an isolated PID namespace, it should add the "pidns"
command to its init script.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-04-04 14:17:08 -04:00
Siddhesh Poyarekar
1c37b8022e Simplify allocations and fix merge and continue actions [BZ #28931]
Allocations for address tuples is currently a bit confusing because of
the pointer chasing through PAT, making it hard to observe the sequence
in which allocations have been made.  Narrow scope of the pointer
chasing through PAT so that it is only used where necessary.

This also tightens actions behaviour with the hosts database in
getaddrinfo to comply with the manual text.  The "continue" action
discards previous results and the "merge" action results in an immedate
lookup failure.  Consequently, chaining of allocations across modules is
no longer necessary, thus opening up cleanup opportunities.

A test has been added that checks some combinations to ensure that they
work correctly.

Resolves: BZ #28931

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: DJ Delorie <dj@redhat.com>
2022-03-22 19:38:36 +05:30
Siddhesh Poyarekar
e2f68b54e8 nss: Sort tests and tests-container and put one test per line
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-03-17 11:16:57 +05:30
Florian Weimer
9bdf92c79d nss: Protect against errno changes in function lookup (bug 28953)
dlopen may clobber errno.  The nss_test_errno module uses an ELF
constructor to achieve that, but there could be internal errors
during dlopen that cause this, too.  Therefore, the NSS framework
has to guard against such errno clobbers.

__nss_module_get_function is currently the only function that calls
__nss_module_load, so it is sufficient to save and restore errno
around this call.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-03-11 08:24:19 +01:00
Florian Weimer
aefc79ab5a nss: Do not mention NSS test modules in <gnu/lib-names.h>
They are not actually installed.  Use the nss_files version instead
in nss/Makefile, similar to how __nss_shlib_revision is derived
from LIBNSS_FILES_SO.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-03-11 08:24:04 +01:00
Paul Eggert
634b5ebac6 Update copyright dates not handled by scripts/update-copyrights.
I've updated copyright dates in glibc for 2022.  This is the patch for
the changes not generated by scripts/update-copyrights and subsequent
build / regeneration of generated files.  As well as the usual annual
updates, mainly dates in --version output (minus csu/version.c which
previously had to be handled manually but is now successfully updated
by update-copyrights), there is a small change to the copyright notice
in NEWS which should let NEWS get updated automatically next year.

Please remember to include 2022 in the dates for any new files added
in future (which means updating any existing uncommitted patches you
have that add new files to use the new copyright dates in them).
2022-01-01 11:42:26 -08:00
Paul Eggert
581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00
Florian Weimer
b99b0f93ee 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>
2021-12-17 12:01:25 +01:00