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>
(cherry picked from commit 9bdf92c79d)
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>
(cherry picked from commit aefc79ab5a)
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 b99b0f93ee)
When a local resolver like unbound is listening on the IPv4 loopback
address 127.0.0.1, the nss/tst-nss-files-hosts-long test fails. This is
due to:
- the default resolver in the absence of resolv.conf being 127.0.0.1
- the default DNS NSS database configuration in the absence of
nsswitch.conf being 'hosts: dns [!UNAVAIL=return] file'
This causes the requests for 'test4' and 'test6' to first be sent to the
local resolver, which responds with NXDOMAIN in the likely case those
records do no exist. In turn that causes the access to /etc/hosts to be
skipped, which is the purpose of that test.
Fix that by providing a simple nsswitch.conf file forcing access to
/etc/hosts for that test. I have tested that the only changed result in
the testsuite is that test.
(cherry picked from commit 2738480a4b)
This partially fixes static-only NSS support (bug 27959): The dns
module no longer needs dlopen. Support for disabling dlopen altogher
remains to be added.
This commit introduces module_load_builtin into nss/nss_module.c, which
handles the common parts of loading the built-in nss_files and nss_dns
modules.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
The error is as follows:
nss_module.c: In function 'module_load_nss_files':
nss_module.c:117:7: error: 'is_nscd' undeclared (first use in this function)
117 | if (is_nscd)
| ^~~~~~~
nss_module.c:117:7: note: each undeclared identifier is reported only once for each function it appears in
nss_module.c:119:51: error: 'nscd_init_cb' undeclared (first use in this function); did you mean 'nscd_init'?
119 | void (*cb) (size_t, struct traced_file *) = nscd_init_cb;
| ^~~~~~~~~~~~
| nscd_init
Sometimes the test nss/tst-nss-files-hosts-long is failing as getent
fails with exit-code 2.
This happens if tst-reload1 was run just before this test:
make t=nss/tst-reload1 test
make t=nss/tst-nss-files-hosts-long test
Then the test fails as /etc/nsswitch.conf contains "hosts: test2"
and the hosts are not searched in /etc/hosts at all.
Thus this patch just requests a post cleanup after nss/tst-reload1
has run.
This partially fixes static-only NSS support (bug 27959): The files
module no longer needs dlopen. Support for the dns module remains
to be added, and also support for disabling dlopen altogether.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This is only needed if nss_files is loaded by nscd.
Before:
text data bss dec hex filename
767 0 24952 25719 6477 nss/files-init.os
After:
text data bss dec hex filename
666 0 0 666 29a nss/files-init.os
Using PATH_MAX bytes unconditionally for the directory name
is wasteful, but fixing that would constitute another break
of this semi-public ABI. (The other issue is that with
symbolic links, an arbitrary set of parent directories may need
watching, not just a single one.)
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
For the legacy ABI with supports 32-bit time_t it calls the 64-bit
time directly, since the LFS symbols calls the 64-bit time_t ones
internally.
Checked on i686-linux-gnu and x86_64-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
This commit removes the ELF constructor and internal variables from
dlfcn/dlfcn.c. The file now serves the same purpose as
nptl/libpthread-compat.c, so it is renamed to dlfcn/libdl-compat.c.
The use of libdl-shared-only-routines ensures that libdl.a is empty.
This commit adjusts the test suite not to use $(libdl). The libdl.so
symbolic link is no longer installed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This change continues the improvements to compile-time out of bounds
checking by decorating more APIs with either attribute access, or by
explicitly providing the array bound in APIs such as tmpnam() that
expect arrays of some minimum size as arguments. (The latter feature
is new in GCC 11.)
The only effects of the attribute and/or the array bound is to check
and diagnose calls to the functions that fail to provide a sufficient
number of elements, and the definitions of the functions that access
elements outside the specified bounds. (There is no interplay with
_FORTIFY_SOURCE here yet.)
Tested with GCC 7 through 11 on x86_64-linux.
__nss_database_lookup2's extra arguments were left unused in the
nsswitch reloading patch set; this broke compat (default config
ignored) and shadow files (secondary name ignored) which relies on
these fallbacks.
This patch adds in the previous behavior by correcting the
initialization of the database list to reflect the fallbacks. This
means that the nss_database_lookup2 interface no longer needs to be
passed the fallback info, so API and callers were adjusted.
Since all callers needed to be edited anyway, the calls were changed
from __nss_database_lookup2 to the faster __nss_database_get. This
was an intended optimization which was deferred during the initial
lookup changes to avoid touching so many files.
The test case verifies that compat targets work (passwd) and that the
default configuration works (group). Tested on x86-64.
The glibc 2.33 release enabled /etc/nsswitch.conf reloading,
and to prevent potential security issues like CVE-2019-14271
the re-loading of nsswitch.conf and all mdoules was disabled
when the root filesystem changes (see bug 27077).
Unfortunately php-lpfm and openldap both require the ability
to continue to load NSS modules after chroot. The packages
do not exec after the chroot, and so do not cause the
protections to be reset. The only solution is to re-enable
only NSS module loading (not nsswitch.conf reloading) and so
get back the previous glibc behaviour.
In the future we may introduce a way to harden applications
so they do not reload NSS modules once the root filesystem
changes, or that only files/dns are available pre-loaded
(or builtin).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Before the change nss_database_check_reload_and_get() did not populate
the '*result' value when it returned success in a case of chroot
detection. This caused initgroups() to use garage pointer in the
following test (extracted from unbound):
```
int main() {
// load some NSS modules
struct passwd * pw = getpwnam("root");
chdir("/tmp");
chroot("/tmp");
chdir("/");
// access nsswitch.conf in a chroot
initgroups("root", 0);
}
```
Reviewed-by: DJ Delorie <dj@redhat.com>
https://sourceware.org/bugzilla/show_bug.cgi?id=27077
Before reloading nsswitch.conf, verify that the root directory
hasn't changed - if it has, it's likely that we've entered a
container and should not trust the nsswitch inside the container
nor load any shared objects therein.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
I've updated copyright dates in glibc for 2021. 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 2021 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).
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 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
Some internal functions need to know if a database has a nonzero
list of actions; success getting the database does not guarantee
that. Add checks for such as needed.
Skip the ":" in each nsswitch.conf line so as not to add a dummy
action libnss_:.so
See also https://bugzilla.redhat.com/show_bug.cgi?id=1906066
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Starting with recent commits, I get 43 conform/.../linknamespace FAILs:
- nss: Introduce <nss_module.h>
- <nss_action.h>: New abstraction for combining NSS modules and NSS actions
- nss: Implement <nss_database.h> (see nss/nss_database.c)
- nsswitch: use new internal API (core)
- nsswitch: user new internal API (tests)
- nsswitch: use new internal API (callers)
e.g. conform/XPG42/wordexp.h/linknamespace.out
[initial] wordexp -> [libc.a(wordexp.o)] __getpwnam_r -> [libc.a(getpwnam_r.o)] __nss_database_custom -> [libc.a(nsswitch.o)] __nss_database_get -> [libc.a(nss_database.o)] feof_unlocked
[initial] wordexp -> [libc.a(wordexp.o)] __getpwnam_r -> [libc.a(getpwnam_r.o)] __nss_database_custom -> [libc.a(nsswitch.o)] __nss_database_get -> [libc.a(nss_database.o)] ferror_unlocked
This patch is just using __ferror_unlocked and __feof_unlocked instead of the
non "__" prefixed ones.
Reviewed-by: DJ Delorie <dj@redhat.com>
This code manages the mappings of the available databases in NSS
(i.e. passwd, hosts, netgroup, etc) with the actions that should
be taken to do a query on those databases.
This is the main API between query functions scattered throughout
glibc and the underlying code (actions, modules, etc).
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
nss_action manages a set of lists of actions; these are the portions
of the lines in nsswitch.conf to the right of the colons, like
"dns [!UNAVAIL=return] files". Each permutation of actions and
conditionals is cached for reuse, which limits memory growth, and
refers to the static list of modules managed by nss_modules.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
This provides the struct nss_module type, which combines the old
struct service_library type with the known_function tree, by
statically allocating space for all function pointers.
struct nss_module is fairly large (536 bytes), but it will be
shared across NSS databases. The old known_function handling
had non-some per-function overhead (at least 32 bytes per looked-up
function, but more for long function anmes), so overall, this is not
too bad. Resolving all functions at load time simplifies locking,
and the repeated lookups should be fast because the caches are hot
at this point.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
The tls.h inclusion is not really required and limits possible
definition on more arch specific headers.
This is a cleanup to allow inline functions on sysdep.h, more
specifically on i386 and ia64 which requires to access some tls
definitions its own.
No semantic changes expected, checked with a build against all
affected ABIs.
The SELinux API deprecated several symbols in its 3.1 release, including
security_context_t, matchpathcon, avc_init, and sidput, which are used in
makedb and nscd. While the usage of these should eventually be replaced by
newer interfaces, this commit disables GCC warnings due to the use of the
above symbols.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
And helper functions __nss_readline, __nss_readline_seek,
__nss_parse_line_result.
This consolidates common code for handling overlong lines and
parse files. Use the new functionality in internal_getent
in nss/nss_files/files-XXX.c.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
As a result, all parse_line functions have the same prototype, except
for that producing struct hostent. This change is ABI-compatible, so
it does not alter the internal GLIBC_PRIVATE ABI (otherwise we should
probably have renamed the exported functions).
A future change will use this to implement a generict fget*ent_r
function.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
These functions should eventually have the same type, so it makes
sense to declare them together.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This avoids crashes in case the files are truncated for some reason.
For typically file sizes, it is also going to be slightly faster.
Using __nss_files_fopen instead mirrors what nss_files does.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
this means that *always* libnsl is only built as shared library for
backward compatibility and the NSS modules libnss_nis and libnss_nisplus
are not built at all, libnsl's headers aren't installed.
This compatibility is kept only for architectures and ABIs that have
been added in or before version 2.28.
Replacement implementations based on TIRPC, which additionally support
IPv6, are available from <https://github.com/thkukuk/>.
This change does not affect libnss_compat which does not depended
on libnsl since 2.27 and thus can be used without NIS.
libnsl code depends on Sun RPC, e.g. on --enable-obsolete-rpc (installed
libnsl headers use installed Sun RPC headers), which will be removed in
the following commit.
The interface has hard-coded buffer sizes and is therefore tied to
DES. It also does not match current practice where different
services on the same host use different key material.
This change simplifies removal of the sunrpc code.
During cleanup, before returning from get*_r functions, the end*ent
calls must not change errno. Otherwise, an ERANGE error from the
underlying implementation can be hidden, causing unexpected lookup
failures. This commit introduces an internal_end*ent_noerror
function which saves and restore errno, and marks the original
internal_end*ent function as warn_unused_result, so that it is used
only in contexts were errors from it can be handled explicitly.
Reviewed-by: DJ Delorie <dj@redhat.com>
I've updated copyright dates in glibc for 2020. 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 libc.texinfo which
previously had to be handled manually but is now successfully updated
by update-copyrights), there is a fix to
sysdeps/unix/sysv/linux/powerpc/bits/termios-c_lflag.h where a typo in
the copyright notice meant it failed to be updated automatically.
Please remember to include 2020 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).
