Commit Graph

143 Commits

Author SHA1 Message Date
Paul Eggert
dff8da6b3e Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
Joseph Myers
6d7e8eda9b Update copyright dates with scripts/update-copyrights 2023-01-06 21:14:39 +00:00
Florian Weimer
f282cdbe7f resolv: Implement no-aaaa stub resolver option
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-06-24 18:18:44 +02:00
John David Anglin
05dec22d7b resolv: Fix unaligned accesses to fields in HEADER struct
The structure HEADER is normally aligned to a word boundary but
sometimes it needs to be accessed when aligned on a byte boundary.
This change defines a new typedef, UHEADER, with alignment 1.
It is used to ensure the fields are accessed with byte loads and
stores when necessary.

V4: Change to res_mkquery.c deleted.  Small whitespace fix.

V5: Move UHEADER typedef to resolv/resolv-internal.h.  Replace all
HEADER usage with UHEADER in resolv/res_send.c.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-03-22 17:35:54 +00:00
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
b165c65c35 resolv: Move res_send, res_nsend into libc
Switch to public symbols without __ prefix (due to improved
namespace management).

__res_send, __res_nsend were moved using the script (with
--no-new-version).  res_send@@GLIBC_2.34 and res_nsend@@GLIBC_2.34
were added using make update-all-abi.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-19 07:56:45 +02:00
Florian Weimer
7131727c6b resolv: Move res_queriesmatch to its own file and into libc
And reformat it to GNU style.

The treatment of this function matches res_nameinquery, for the
reasons stated there.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-19 07:56:21 +02:00
Florian Weimer
72a51ac647 resolv: Move res_nameinquery to its own file and into libc
And reformat to GNU style.

This deprecated function is used in the implementation of the stub
resolver (for now).  Keep the public symbol in libresolv for now
(so that no new symbol version is needed), and add a forwarder to
libresolv.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-19 07:56:21 +02:00
Florian Weimer
762a2b2d34 resolv: Move ns_samename into its own file, and into libc
But only as an internal symbol, __libc_ns_samename.  The libresolv
ABI is preserved.  This is because the function is deprecated, and
it does not make sense to add new symbol versions for deprecated
functions.

Also reformat the implementation to GNU style.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-19 07:56:21 +02:00
Florian Weimer
17d0407a5c resolv: Move res_isourserver to its own file and reformat to GNU style
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-19 07:56:21 +02:00
Florian Weimer
9515126f90 resolv: Move __res_get_nsaddr to its own file and into libc
Eliminate the use of the EXT macro from it because it does not
add clarity.  The function was added to res_send.c in 2015, and
the copyright year reflects that.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-19 07:56:21 +02:00
Florian Weimer
640bbdf71c resolv: Move dn_expand to its own file and into libc
And reformat to GNU style.

This switches back to the dn_expand name for the ABI symbol and turns
__dn_expand into a compatibility symbol.  With the improved namespace
management in current glibc, it is no longer necessary to use a
private namespace symbol.  To avoid old code binding to a
GLIBC_PRIVATE symbol by accident, use __libc_dn_expand for the
internal symbol name.

The symbols dn_expand, __dnexpand were moved using
scripts/move-symbol-to-libc.py, followed by an adjustment to make
dn_expand the only GLIBC_2.34 symbol.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-19 07:56:21 +02:00
Florian Weimer
ee3639e0fe resolv: Remove unnecessary res_isourserver_p call from send_dg
As the comment indicates, the check is unnecessary due to the way the
UDP socket is set up.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-15 09:00:24 +02:00
Paul Eggert
2b778ceb40 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 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
2021-01-02 12:17:34 -08:00
Florian Weimer
f1f00c0721 resolv: Handle transaction ID collisions in parallel queries (bug 26600)
If the transaction IDs are equal, the old check attributed both
responses to the first query, not recognizing the second response.
This fixes bug 26600.
2020-10-14 10:54:39 +02:00
Stefan Liebler
aba12794dc Get rid of Werror=maybe-uninitialized in res_send.c.
The commit 446997ff14 introduced
this new usage of resplen. If build with gcc 9 -march>=z13 on s390x,
the following warning occurs:
res_send.c: In function ‘__res_context_send’:
res_send.c:539:6: error: ‘resplen’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  539 |   if (resplen > HFIXEDSZ)
      |      ^

Therefore this patch adds a further DIAG_IGNORE_NEEDS_COMMENT in the
same way as it was previously done for usages of resplen or n.
See commit d1bc2cbbed.
2020-01-20 10:57:08 +01:00
Joseph Myers
d614a75396 Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Florian Weimer
446997ff14 resolv: Implement trust-ad option for /etc/resolv.conf [BZ #20358]
This introduces a concept of trusted name servers, for which the
AD bit is passed through to applications.  For untrusted name
servers (the default), the AD bit in responses are cleared, to
provide a safe default.

This approach is very similar to the one suggested by Pavel Šimerda
in <https://bugzilla.redhat.com/show_bug.cgi?id=1164339#c15>.

The DNS test framework in support/ is enhanced with support for
setting the AD bit in responses.

Tested on x86_64-linux-gnu.

Change-Id: Ibfe0f7c73ea221c35979842c5c3b6ed486495ccc
2019-11-27 20:54:37 +01:00
Zack Weinberg
4a39c34c4f Change most internal uses of __gettimeofday to __clock_gettime.
Since gettimeofday will shortly be implemented in terms of
clock_gettime on all platforms, internal code should use clock_gettime
directly; in addition to removing a layer of indirection, this will
allow us to remove the PLT-bypass gunk for gettimeofday.  (We can't
quite do that yet, but it'll be coming later in this patch series.)
In many cases, the changed code does fewer conversions.

The changed code always assumes __clock_gettime (CLOCK_REALTIME)
cannot fail.  Most of the call sites were assuming gettimeofday could
not fail, but a few places were checking for errors.  POSIX says
clock_gettime can only fail if the clock constant is invalid or
unsupported, and CLOCK_REALTIME is the one and only clock constant
that's required to be supported.  For consistency I grepped the entire
source tree for any other places that checked for errors from
__clock_gettime (CLOCK_REALTIME), found one, and changed it too.

(For the record, POSIX also says gettimeofday can never fail.)

(It would be nice if we could declare that GNU systems will always
support CLOCK_MONOTONIC as well as CLOCK_REALTIME; there are several
places where we are using CLOCK_REALTIME where _MONOTONIC would be
more appropriate, and/or trying to use _MONOTONIC and then falling
back to _REALTIME.  But the Hurd doesn't support CLOCK_MONOTONIC yet,
and it looks like adding it would involve substantial changes to
gnumach's internals and API.  Oh well.)

A few Hurd-specific files were changed to use __host_get_time instead
of __clock_gettime, as this seemed tidier.  We also assume this cannot
fail.  Skimming the code in gnumach leads me to believe the only way
it could fail is if __mach_host_self also failed, and our
Hurd-specific code consistently assumes that can't happen, so I'm
going with that.

With the exception of support/support_test_main.c, test cases are not
modified, mainly because I didn't want to have to figure out which
test cases were testing gettimeofday specifically.

The definition of GETTIME in sysdeps/generic/memusage.h had a typo and
was not reading tv_sec at all.  I fixed this.  It appears nobody has been
generating malloc traces on a machine that doesn't have a superseding
definition.

There are a whole bunch of places where the code could be simplified
by factoring out timespec subtraction and/or comparison logic, but I
want to keep this patch as mechanical as possible.

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
2019-10-30 17:04:10 -03:00
Paul Eggert
5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 02:43:31 -07:00
Stefan Liebler
d1bc2cbbed Fix build warnings in resolv/res_send.c
This patch fixes the gcc warnings seen with gcc 9 -march>=z13 on s390x:
res_send.c: In function ‘__res_context_send’:
res_send.c:498:7: error: ‘resplen’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  498 |    if (n == 0 && (buf2 == NULL || *resplen2 == 0))
      |       ^

In this case send_vc is inlined into __res_context_send
and the maybe uninitialized resplen belongs to the one in send_vc.

In send_vc there is already a DIAG_IGNORE_NEEDS_COMMENT (5, "-Wmaybe-uninitialized")
and a comment which explains that this is a false-positive.
Note that resplen is used as return value.

This patch adds a further DIAG_IGNORE_NEEDS_COMMENT around the declaration of n
in __res_context_send and the comparison after n was set to the return value of send_vc.

ChangeLog:

	* resolv/res_send.c (__res_context_send): Disable maybe-uninitialized
	warning.
2019-07-02 14:07:44 +02:00
Florian Weimer
333221862e resolv: Remove RES_INSECURE1, RES_INSECURE2
Always perform the associated security checks.
2019-04-08 11:19:38 +02:00
Adhemerval Zanella
359653aaac Do not use HP_TIMING_NOW for random bits
This patch removes the HP_TIMING_BITS usage for fast random bits and replace
with clock_gettime (CLOCK_MONOTONIC).  It has unspecified starting time and
nano-second accuracy, so its randomness is significantly better than
gettimeofday.

Althoug it should incur in more overhead (specially for architecture that
support hp-timing), the symbol is also common implemented as a vDSO.

Checked on aarch64-linux-gnu, x86_64-linux-gnu, and i686-linux-gnu. I also
checked on a i686-gnu build.

	* include/random-bits.h: New file.
	* resolv/res_mkquery.c [HP_TIMING_AVAIL] (RANDOM_BITS,
	(__res_context_mkquery): Remove usage hp-timing usage and replace with
	random_bits.
	* resolv/res_send.c [HP_TIMING_AVAIL] (nameserver_offset): Likewise.
	* sysdeps/posix/tempname.c [HP_TIMING_AVAIL] (__gen_tempname):
	Likewise.
2019-03-22 17:30:39 -03:00
Florian Weimer
08504de718 resolv: Enable full ICMP errors for UDP DNS sockets [BZ #24047]
The Linux kernel suppresses some ICMP error messages by default for
UDP sockets.  This commit enables full ICMP error reporting,
hopefully resulting in faster failover to working name servers.
2019-03-12 11:40:47 +01:00
Joseph Myers
04277e02d7 Update copyright dates with scripts/update-copyrights.
* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.
2019-01-01 00:11:28 +00:00
Andreas Schwab
dae6c43c33 Remove unneeded setting of errno after malloc failure
The errno value has alread been set by malloc.
2018-05-17 15:47:25 +02:00
Florian Weimer
583a27d525 resolv: Fully initialize struct mmsghdr in send_dg [BZ #23037] 2018-04-09 10:08:16 +02:00
Andreas Schwab
f178e59fa5 Fix crash in resolver on memory allocation failure (bug 23005) 2018-03-27 17:26:32 +02:00
Joseph Myers
688903eb3e Update copyright dates with scripts/update-copyrights.
* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.
2018-01-01 00:32:25 +00:00
Florian Weimer
352f4ff9a2 resolv: Introduce struct resolv_context [BZ #21668]
struct resolv_context objects provide a temporary resolver context
which does not change during a name lookup operation.  Only when the
outmost context is created, the stub resolver configuration is
verified to be current (at present, only against previous res_init
calls).  Subsequent attempts to obtain the context will reuse the
result of the initial verification operation.

struct resolv_context can also be extended in the future to store
data which needs to be deallocated during thread cancellation.
2017-07-03 20:52:59 +02:00
Florian Weimer
ded603542a resolv: Move res_isourserver, res_send from res_data.c to res_send.c 2017-06-30 11:31:48 +02:00
Florian Weimer
09fbb56ad6 resolv: Remove DEBUG from resolv/res_send.c 2017-06-30 11:31:24 +02:00
Florian Weimer
5b757a51b5 resolv: Make RES_ROTATE start with a random name server [BZ #19570]
Do not copy the actual name server addresses to rotate them.  Use a
global rotation offset instead.
2017-06-30 10:43:33 +02:00
Florian Weimer
bee05c9d58 resolv: Replace __builtin_expect with __glibc_unlikely/__glibc_likely 2017-04-19 14:29:24 +02:00
Florian Weimer
2f83a7294d Create more sockets with SOCK_CLOEXEC [BZ #15722] 2017-04-19 07:45:04 +02:00
Florian Weimer
44500cbb25 resolv: Remove EDNS fallback [BZ #21369]
EDNS is disabled by default (so there is interoperability issue), and
the fallback code is problematic because it prevents an application
from obtaining DNSSEC data after a FORMERR response.
2017-04-13 13:22:51 +02:00
Florian Weimer
a7ff1da823 resolv: Remove internal and unused definitions from <resolv.h>
The RES_F_* constants are only used with the private _res._flags
member.  RES_EXHAUSTIVE is unused.  The removed function
declarations refer to functions not actually exported by glibc,
so they are unusable by applications.
2017-04-13 10:52:42 +02:00
Zack Weinberg
9090848d06 Narrowing the visibility of libc-internal.h even further.
posix/wordexp-test.c used libc-internal.h for PTR_ALIGN_DOWN; similar
to what was done with libc-diag.h, I have split the definitions of
cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and PTR_ALIGN_DOWN
to a new header, libc-pointer-arith.h.

It then occurred to me that the remaining declarations in libc-internal.h
are mostly to do with early initialization, and probably most of the
files including it, even in the core code, don't need it anymore.  Indeed,
only 19 files actually need what remains of libc-internal.h.  23 others
need libc-diag.h instead, and 12 need libc-pointer-arith.h instead.
No file needs more than one of them, and 16 don't need any of them!

So, with this patch, libc-internal.h stops including libc-diag.h as
well as losing the pointer arithmetic macros, and all including files
are adjusted.

        * include/libc-pointer-arith.h: New file.  Define
	cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and
        PTR_ALIGN_DOWN here.
        * include/libc-internal.h: Definitions of above macros
	moved from here.  Don't include libc-diag.h anymore either.
	* posix/wordexp-test.c: Include stdint.h and libc-pointer-arith.h.
        Don't include libc-internal.h.

	* debug/pcprofile.c, elf/dl-tunables.c, elf/soinit.c, io/openat.c
	* io/openat64.c, misc/ptrace.c, nptl/pthread_clock_gettime.c
	* nptl/pthread_clock_settime.c, nptl/pthread_cond_common.c
	* string/strcoll_l.c, sysdeps/nacl/brk.c
	* sysdeps/unix/clock_settime.c
	* sysdeps/unix/sysv/linux/i386/get_clockfreq.c
	* sysdeps/unix/sysv/linux/ia64/get_clockfreq.c
	* sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
	* sysdeps/unix/sysv/linux/sparc/sparc64/get_clockfreq.c:
	Don't include libc-internal.h.

	* elf/get-dynamic-info.h, iconv/loop.c
	* iconvdata/iso-2022-cn-ext.c, locale/weight.h, locale/weightwc.h
	* misc/reboot.c, nis/nis_table.c, nptl_db/thread_dbP.h
	* nscd/connections.c, resolv/res_send.c, soft-fp/fmadf4.c
	* soft-fp/fmasf4.c, soft-fp/fmatf4.c, stdio-common/vfscanf.c
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c
	* sysdeps/ieee754/dbl-64/k_rem_pio2.c
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c
	* sysdeps/ieee754/flt-32/k_rem_pio2f.c
	* sysdeps/ieee754/ldbl-128/k_tanl.c
	* sysdeps/ieee754/ldbl-128ibm/k_tanl.c
	* sysdeps/ieee754/ldbl-96/e_lgammal_r.c
	* sysdeps/ieee754/ldbl-96/k_tanl.c, sysdeps/nptl/futex-internal.h:
	Include libc-diag.h instead of libc-internal.h.

        * elf/dl-load.c, elf/dl-reloc.c, locale/programs/locarchive.c
        * nptl/nptl-init.c, string/strcspn.c, string/strspn.c
	* malloc/malloc.c, sysdeps/i386/nptl/tls.h
	* sysdeps/nacl/dl-map-segments.h, sysdeps/x86_64/atomic-machine.h
	* sysdeps/unix/sysv/linux/spawni.c
        * sysdeps/x86_64/nptl/tls.h:
        Include libc-pointer-arith.h instead of libc-internal.h.

	* elf/get-dynamic-info.h, sysdeps/nacl/dl-map-segments.h
	* sysdeps/x86_64/atomic-machine.h:
        Add multiple include guard.
2017-03-01 20:33:46 -05:00
Joseph Myers
bfff8b1bec Update copyright dates with scripts/update-copyrights. 2017-01-01 00:14:16 +00:00
Florian Weimer
bbe989ee87 resolv: Deprecate RES_BLAST 2016-12-31 19:08:39 +01:00
Dmitry V. Levin
12f1ae05c0 Fix typos in the spelling of "implementation"
Apply the following spelling fix:
$ git grep -El 'implemetn?ation' |
  xargs sed -ri 's/implemetn?ation/implementation/g'

[BZ #19514]
* resolv/res_send.c: Fix typo in comment.
* sysdeps/i386/i386-mcount.S: Likewise.
* sysdeps/s390/s390-32/s390-mcount.S: Likewise.
* sysdeps/s390/s390-64/s390x-mcount.S: Likewise.
* sysdeps/sparc/sparc-mcount.S: Likewise.
2016-12-27 20:13:35 +00:00
Carlos O'Donell
0cb9dcc8f2 Bug 20729: Fix build failures on ppc64 and other arches.
The changes to fix bug 20729 introduced an error which removed an
ignore diagnostic from -O2 by using the new -Os related macro.
This broke ppc64 builds. This commit fixes the mistake.

Tested on x86, x86_64, ppc64, ppc64le, arm, aarch64, and s390x.
2016-11-02 13:01:36 -04:00
Carlos O'Donell
93fe09cb5f Bug 20729: Fix building with -Os.
This commit adds a new DIAG_IGNORE_Os_NEEDS_COMMENT which is only
enabled when compiling with -Os. This allows developers working on
-Os enabled builds to mark false-positive warnings without impacting the
warnings emitted at -O2.

Then using the new DIAG_IGNORE_Os_NEEDS_COMMENT we fix 6 warnings
generated with GCC 5 to get -Os builds working again.
2016-10-29 23:50:56 -04:00
Florian Weimer
6815a33d53 resolv: Remove unsupported hook functions from the API [BZ #20016] 2016-09-21 16:30:27 +02:00
Florian Weimer
1f32be054b resolv: Remove SCCS and RCS keywords 2016-04-28 12:53:49 +02:00
Florian Weimer
b9bdfa7c8f resolv: Always set *resplen2 out parameter in send_vc [BZ #19825]
In various error scenarios (for example, if the server closes the
TCP connection before sending the full response), send_vc can return
without resetting the *resplen2 value.  This can pass uninitialized
or unexpected data to the caller.
2016-04-27 14:26:47 +02:00
Florian Weimer
b66d837bb5 resolv: Always set *resplen2 out parameter in send_dg [BZ #19791]
Since commit 44d20bca52 (Implement
second fallback mode for DNS requests), there is a code path which
returns early, before *resplen2 is initialized.  This happens if the
name server address is immediately recognized as invalid (because of
lack of protocol support, or if it is a broadcast address such
255.255.255.255, or another invalid address).

If this happens and *resplen2 was non-zero (which is the case if a
previous query resulted in a failure), __libc_res_nquery would reuse
an existing second answer buffer.  This answer has been previously
identified as unusable (for example, it could be an NXDOMAIN
response).  Due to the presence of a second answer, no name server
switching will occur.  The result is a name resolution failure,
although a successful resolution would have been possible if name
servers have been switched and queries had proceeded along the search
path.

The above paragraph still simplifies the situation.  Before glibc
2.23, if the second answer needed malloc, the stub resolver would
still attempt to reuse the second answer, but this is not possible
because __libc_res_nsearch has freed it, after the unsuccessful call
to __libc_res_nquerydomain, and set the buffer pointer to NULL.  This
eventually leads to an assertion failure in __libc_res_nquery:

	/* Make sure both hp and hp2 are defined */
	assert((hp != NULL) && (hp2 != NULL));

If assertions are disabled, the consequence is a NULL pointer
dereference on the next line.

Starting with glibc 2.23, as a result of commit
e9db92d3ac (CVE-2015-7547: getaddrinfo()
stack-based buffer overflow (Bug 18665)), the second answer is always
allocated with malloc.  This means that the assertion failure happens
with small responses as well because there is no buffer to reuse, as
soon as there is a name resolution failure which triggers a search for
an answer along the search path.

This commit addresses the issue by ensuring that *resplen2 is
initialized before the send_dg function returns.

This commit also addresses a bug where an invalid second reply is
incorrectly returned as a valid to the caller.
2016-03-25 11:49:52 +01:00
Carlos O'Donell
e9db92d3ac CVE-2015-7547: getaddrinfo() stack-based buffer overflow (Bug 18665).
* A stack-based buffer overflow was found in libresolv when invoked from
  libnss_dns, allowing specially crafted DNS responses to seize control
  of execution flow in the DNS client.  The buffer overflow occurs in
  the functions send_dg (send datagram) and send_vc (send TCP) for the
  NSS module libnss_dns.so.2 when calling getaddrinfo with AF_UNSPEC
  family.  The use of AF_UNSPEC triggers the low-level resolver code to
  send out two parallel queries for A and AAAA.  A mismanagement of the
  buffers used for those queries could result in the response of a query
  writing beyond the alloca allocated buffer created by
  _nss_dns_gethostbyname4_r.  Buffer management is simplified to remove
  the overflow.  Thanks to the Google Security Team and Red Hat for
  reporting the security impact of this issue, and Robert Holiday of
  Ciena for reporting the related bug 18665. (CVE-2015-7547)

See also:
https://sourceware.org/ml/libc-alpha/2016-02/msg00416.html
https://sourceware.org/ml/libc-alpha/2016-02/msg00418.html
2016-02-16 21:29:32 -05:00
Martin Sebor
f2b3078e6a Fix build failures with -DDEBUG.
[BZ #19443]
        * crypt/crypt_util.c [DEBUG] (_ufc_prbits): Correct format string.
        [DEBUG] (_ufc_set_bits): Declare used.
        * iconv/gconv_dl.c [DEBUG]: Add a missing include directive.
        [DEBUG] (print_all): Declare used.
        * resolv/res_send.c [DEBUG] (__libc_res_nsend): Explicitly convert
        operands of the ternary ?: expression to target type.
        * stdlib/rshift.c [DEBUG] (mpn_rshift): Use assert() instead of
        calling the undeclared abort.
        * time/mktime.c [DEBUG] (DEBUG): Rename to DEBUG_MKTIME.
2016-01-15 11:07:41 -07:00
Joseph Myers
f1d237df1e Remove GCC version conditionals on -Wmaybe-uninitialized pragmas.
One common case of __GNUC_PREREQ (4, 7) conditionals is use of
diagnostic control pragmas for -Wmaybe-uninitialized, an option
introduced in GCC 4.7 where older GCC needed -Wuninitialized to be
controlled instead if the warning appeared with older GCC.  This patch
removes such conditionals.

(There remain several older uses of -Wno-uninitialized in makefiles
that still need to be converted to diagnostic control pragmas if the
issue is still present with current sources and supported GCC
versions, and it's likely that in most cases those pragmas also will
end up controlling -Wmaybe-uninitialized.)

Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch, except for libresolv
since res_send.c contains assertions whose line numbers are changed by
the patch).

	* resolv/res_send.c (send_vc) [__GNUC_PREREQ (4, 7)]: Make code
	unconditional.
	* soft-fp/fmadf4.c [__GNUC_PREREQ (4, 7)]: Likewise.
	[!__GNUC_PREREQ (4, 7)]: Remove conditional code.
	* soft-fp/fmasf4.c [__GNUC_PREREQ (4, 7)]: Make code
	unconditional.
	[!__GNUC_PREREQ (4, 7)]: Remove conditional code.
	* soft-fp/fmatf4.c [__GNUC_PREREQ (4, 7)]: Make code
	unconditional.
	[!__GNUC_PREREQ (4, 7)]: Remove conditional code.
	* stdlib/setenv.c
	[((__GNUC__ << 16) + __GNUC_MINOR__) >= ((4 << 16) + 7)]: Make
	code unconditional.
	[!(((__GNUC__ << 16) + __GNUC_MINOR__) >= ((4 << 16) + 7))]:
	Remove conditional code.
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c
	(__ieee754_lgamma_r) [__GNUC_PREREQ (4, 7)]: Make code
	unconditional.
	(__ieee754_lgamma_r) [!__GNUC_PREREQ (4, 7)]: Remove conditional
	code.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c
	(__ieee754_lgammaf_r) [__GNUC_PREREQ (4, 7)]: Make code
	unconditional.
	(__ieee754_lgammaf_r) [!__GNUC_PREREQ (4, 7)]: Remove conditional
	code.
	* sysdeps/ieee754/ldbl-128/k_tanl.c
	(__kernel_tanl) [__GNUC_PREREQ (4, 7)]: Make code unconditional.
	(__kernel_tanl) [!__GNUC_PREREQ (4, 7)]: Remove conditional code.
	* sysdeps/ieee754/ldbl-128ibm/k_tanl.c
	(__kernel_tanl) [__GNUC_PREREQ (4, 7)]: Make code unconditional.
	(__kernel_tanl) [!__GNUC_PREREQ (4, 7)]: Remove conditional code.
	* sysdeps/ieee754/ldbl-96/e_lgammal_r.c
	(__ieee754_lgammal_r) [__GNUC_PREREQ (4, 7)]: Make code
	unconditional.
	(__ieee754_lgammal_r) [!__GNUC_PREREQ (4, 7)]: Remove conditional
	code.
	* sysdeps/ieee754/ldbl-96/k_tanl.c
	(__kernel_tanl) [__GNUC_PREREQ (4, 7)]: Make code unconditional.
	(__kernel_tanl) [!__GNUC_PREREQ (4, 7)]: Remove conditional code.
2015-10-27 23:42:20 +00:00