It replaces the internal usage of __{f,l}xstat{at}{64} with the
__{f,l}stat{at}{64}. It should not change the generate code since
sys/stat.h explicit defines redirections to internal calls back to
xstat* symbols.
Checked with a build for all affected ABIs. I also check on
x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
The symbol is deprecated by strerror since its usage imposes some issues
such as copy relocations.
Its internal name is also changed to _sys_errlist_internal to avoid
static linking usage. The compat code is also refactored by removing
the over enginered errlist-compat.c generation from manual entried and
extra comment token in linker script file. It disantangle the code
generation from manual and simplify both Linux and Hurd compat code.
The definitions from errlist.c are moved to errlist.h and a new test
is added to avoid a new errno entry without an associated one in manual.
Checked on x86_64-linux-gnu and i686-linux-gnu. I also run a check-abi
on all affected platforms.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The symbol was deprecated by strsignal and its usage imposes issues
such as copy relocations.
Its internal name is changed to __sys_siglist and __sys_sigabbrev to
avoid static linking usage. The compat code is also refactored, since
both Linux and Hurd usage the same strategy: export the same array with
different object sizes.
The libSegfault change avoids calling strsignal on the SIGFAULT signal
handler (the current usage is already sketchy, adding a call that
potentially issue locale internal function is even sketchier).
Checked on x86_64-linux-gnu and i686-linux-gnu. I also run a check-abi
on all affected platforms.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This patch adds the new TCP_TX_DELAY constant from Linux 5.3 to
sysdeps/gnu/netinet/tcp.h.
Tested for x86_64.
* sysdeps/gnu/netinet/tcp.h (TCP_TX_DELAY): New macro.
Commit 7532837d7b ("The
-Wstringop-truncation option new in GCC 8 detects common misuses")
added __attribute_nonstring__ to bits/utmp.h, but it did not update
the parallel bits/utmpx.h header. In struct utmp, the nonstring
attribute for ut_id was missing.
This patch adds constants from netinet/tcp.h in Linux 4.18, and an
associated struct tcp_zerocopy_receive, to sysdeps/gnu/netinet/tcp.h.
The new TCP_REPAIR_* constants seemed sufficiently related to those
already present to include them.
Note that this patch does not include additions to struct tcp_info;
there are many other elements in this structure in the Linux kernel
that are not included in the glibc version (which was last extended in
2007, it seems). Such additions to the end of the structure may be OK
with the expected way it is used (size passed explicitly to the kernel
with getsockopt), but in principle any change to the size of a type
provided by glibc is an ABI change for external applications /
libraries using that type in their ABIs, and has the associated risks
of such a change.
Tested for x86_64.
* sysdeps/gnu/netinet/tcp.h (TCP_ZEROCOPY_RECEIVE): New macro.
(TCP_INQ): Likewise.
(TCP_CM_INQ): Likewise.
(TCP_REPAIR_ON): Likewise.
(TCP_REPAIR_OFF): Likewise.
(TCP_REPAIR_OFF_NO_WP): Likewise.
(struct tcp_zerocopy_receive): New type.
Prevent random runtime crashes due to missing symbols caused by mixed
libnss_* versions.
[BZ #22766]
* include/dlfcn.h [__libc_dl_open]: Replace RTLD_LAZY with RTLD_NOW.
* sysdeps/gnu/unwind-resume.c (__lib_gcc_s_init): Replace
__libc_dlopen_mode() using RTLD_NOW with __libc_dlopen.
* sysdeps/nptl/unwind-forcedunwind.c: Likewise.
Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* bits/in.h [!__USE_MISC]: Do not define struct ip_opts.
* conform/data/netinet/in.h-data: Allow sin_ and sin6_ prefix.
* sysdeps/gnu/bits/msq.h (struct msqid_ds): Use __wait_queue struct
instead of wait_queue.
* sysdeps/gnu/bits/shm.h (struct shmid_ds): Use __vm_area_struct
instead of vm_area_struct.
* manual/errno.texi (EOWNERDEAD, ENOTRECOVERABLE): Remove errno
values from Linux-specific section now that it is in the GNU section.
* sysdeps/gnu/errlist.c: Regenerate.
This patch adds the TCP_FASTOPEN_KEY and TCP_FASTOPEN_NO_COOKIE macros
from Linux 4.15 to sysdeps/gnu/netinet/tcp.h.
Tested for x86_64.
* sysdeps/gnu/netinet/tcp.h (TCP_FASTOPEN_KEY): New macro.
(TCP_FASTOPEN_NO_COOKIE): Likewise.
The arguments of the LIBC_SLIBDIR_RTLDDIR macro are used both in unquoted
and single quoted context, so that neither shell nor makefile variable
references work. Consistently put them in single quotes so that they can
refer to makefile variables.
This follows ccf970c7a ('posix: Add compat glob symbol to not follow
dangling symbols') by adding to gnu/ the same compatibility as for Linux.
* sysdeps/gnu/glob64.c (__glob): Define macro instead of glob macro.
(__glob64): Define GLIBC_2_27 versioned symbol instead of glob64.
* sysdeps/gnu/glob-lstat-compat.c: New file.
* sysdeps/gnu/glob64-lstat-compat.c: New file.
of the strncat and strncpy function that may result in truncating
the copied string before the terminating NUL. To avoid false positive
warnings for correct code that intentionally creates sequences of
characters that aren't guaranteed to be NUL-terminated, arrays that
are intended to store such sequences should be decorated with a new
nonstring attribute. This change add this attribute to Glibc and
uses it to suppress such false positives.
ChangeLog:
* misc/sys/cdefs.h (__attribute_nonstring__): New macro.
* sysdeps/gnu/bits/utmp.h (struct utmp): Use it.
* sysdeps/unix/sysv/linux/s390/bits/utmp.h (struct utmp): Same.
from `freeaddrinfo'.
`getifaddrs' and `freeifaddrs' are not in POSIX, they should not be
exposed along `freeaddrinfo' (through `__check_pf') which is POSIX.
* include/ifaddrs.h (__getifaddrs, __freeifaddrs): New declarations,
and use libc_hidden_def on them.
* inet/ifaddrs.c (__getifaddrs, __freeifaddrs): Use libc_hidden_def on
them.
* sysdeps/gnu/ifaddrs.c (__getifaddrs, __freeifaddrs): Likewise.
* inet/check_pf.c (__check_pf): Use __getifaddrs and __freeifaddrs
instead of getifaddrs and freeifaddrs.
This patch syncs posix/glob.c implementation with gnulib version
b5ec983 (glob: simplify symlink detection). The only difference
to gnulib code is
* DT_UNKNOWN, DT_DIR, and DT_LNK definition in the case there
were not already defined. Gnulib code which uses
HAVE_STRUCT_DIRENT_D_TYPE will redefine them wrongly because
GLIBC does not define HAVE_STRUCT_DIRENT_D_TYPE. Instead
the patch check for each definition instead.
Also, the patch requires additional globfree and globfree64 files
for compatibility version on some architectures. Also the code
simplification leads to not macro simplification (not need for
NO_GLOB_PATTERN_P anymore).
Checked on x86_64-linux-gnu and on a build using build-many-glibcs.py
for all major architectures.
[BZ #1062]
* posix/Makefile (routines): Add globfree, globfree64, and
glob_pattern_p.
* posix/flexmember.h: New file.
* posix/glob_internal.h: Likewise.
* posix/glob_pattern_p.c: Likewise.
* posix/globfree.c: Likewise.
* posix/globfree64.c: Likewise.
* sysdeps/gnu/globfree64.c: Likewise.
* sysdeps/unix/sysv/linux/alpha/globfree.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/globfree64.c: Likewise.
* sysdeps/unix/sysv/linux/oldglob.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/globfree64.c: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/globfree.c: Likewise.
* sysdeps/wordsize-64/globfree.c: Likewise.
* sysdeps/wordsize-64/globfree64.c: Likewise.
* posix/glob.c (HAVE_CONFIG_H): Use !_LIBC instead.
[NDEBUG): Remove comments.
(GLOB_ONLY_P, _AMIGA, VMS): Remove define.
(dirent_type): New type. Use uint_fast8_t not
uint8_t, as C99 does not require uint8_t.
(DT_UNKNOWN, DT_DIR, DT_LNK): New macros.
(struct readdir_result): Use dirent_type. Do not define skip_entry
unless it is needed; this saves a byte on platforms lacking d_ino.
(readdir_result_type, readdir_result_skip_entry):
New functions, replacing ...
(readdir_result_might_be_symlink, readdir_result_might_be_dir):
these functions, which were removed. This makes the callers
easier to read. All callers changed.
(D_INO_TO_RESULT): Now empty if there is no d_ino.
(size_add_wrapv, glob_use_alloca): New static functions.
(glob, glob_in_dir): Check for size_t overflow in several places,
and fix some size_t checks that were not quite right.
Remove old code using SHELL since Bash no longer
uses this.
(glob, prefix_array): Separate MS code better.
(glob_in_dir): Remove old Amiga and VMS code.
(globfree, __glob_pattern_type, __glob_pattern_p): Move to
separate files.
(glob_in_dir): Do not rely on undefined behavior in accessing
struct members beyond their bounds. Use a flexible array member
instead
(link_stat): Rename from link_exists2_p and return -1/0 instead of
0/1. Caller changed.
(glob): Fix memory leaks.
* posix/glob64 (globfree64): Move to separate file.
* sysdeps/gnu/glob64.c (NO_GLOB_PATTERN_P): Remove define.
(globfree64): Remove hidden alias.
* sysdeps/unix/sysv/linux/Makefile (sysdeps_routines): Add
oldglob.
* sysdeps/unix/sysv/linux/alpha/glob.c (__new_globfree): Move to
separate file.
* sysdeps/unix/sysv/linux/i386/glob64.c (NO_GLOB_PATTERN_P): Remove
define.
Move compat code to separate file.
* sysdeps/wordsize-64/glob.c (globfree): Move definitions to
separate file.
This patch updates sysdeps/gnu/netinet/tcp.h to include new
definitions from include/uapi/linux/tcp.h in Linux 4.13.
Tested for x86_64.
* sysdeps/gnu/netinet/tcp.h (TCP_ULP): New macro.
(TCP_MD5SIG_EXT): Likewise.
(TCP_MD5SIG_FLAG_PREFIX): Likewise.
(struct tcp_md5sig): Replace __tcpm_pad1 by tcpm_flags and
tcpm_prefixlen. Rename __tcpm_pad2 to __tcpm_pad.
errno.texi documents error macros, their values, and error strings in
Texinfo @comments, some of which are also used for @standards. The
purpose of this commit is to separate the standards from the error
strings so that both the @standards conversion script picks up clean
@standards and the errno documentation framework is improved.
The error names, values, and messages are consolidated in a new custom
macro, @errno. It is not clear that scripts within the sources rely
on the special Texinfo @comment-based format to generate files used
throughout the library, so the definition of @errno in macros.texi now
provides a comment indicating the dependency. The dependent scripts
are updated to use @errno, which also simplifies them a bit. The
files those scripts generate were verified to be unchanged.
The @errno macro is not visibly rendered in any way at this time, but
it does use an @cindex command to add the error string to the Concept
Index, to facilitate searching on error messages.
* manual/errno.texi: Convert @comment-based errno
documentation to @errno.
* manual/macros.texi (@errno): New macro. Consolidate errors,
their values, and messages, adding the error string to the
Concept Index. Provide a warning in the comment about
external (to the manual) dependencies.
* sysdeps/gnu/errlist.awk: Use @errno instead of @comments.
* sysdeps/mach/hurd/errnos.awk: Likewise.
This patch adds the TCP_FASTOPEN_CONNECT macro from Linux 4.11 to
sysdeps/gnu/netinet/tcp.h.
Tested for x86-64.
* sysdeps/gnu/netinet/tcp.h (TCP_FASTOPEN_CONNECT): New macro.
Linux 4.8 adds TCP_REPAIR_WINDOW to include/uapi/linux/tcp.h. This
patch adds it to sysdeps/gnu/netinet/tcp.h accordingly, along with
struct tcp_repair_window as requested in
<https://sourceware.org/ml/libc-alpha/2016-10/msg00019.html>.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
* sysdeps/gnu/netinet/tcp.h (TCP_REPAIR_WINDOW): New macro.
(struct tcp_repair_window): New type.
The types u_char, u_short, u_int, u_long, ushort, uint, ulong, u_int8_t,
u_int16_t, u_int32_t, u_int64_t, quad_t, and u_quad_t are BSDisms that
have never been standardized. While glibc should continue to *provide*
these types for compatibility's sake, its public headers should not
use them.
The meat of this change was mechanically generated by the following
shell command:
perl -pi~ -e '
s/\b(__)?u_char\b/unsigned char/g;
s/\b(__)?u_?short\b/unsigned short/g;
s/\b(__)?u_?int\b/unsigned int/g;
s/\b(__)?u_?long\b/unsigned long/g;
s/\b(__)?u_int8_t\b/uint8_t/g;
s/\b(__)?u_int16_t\b/uint16_t/g;
s/\b(__)?u_int32_t\b/uint32_t/g;
s/\b(__)?u_int64_t\b/uint64_t/g;
s/\b(__)?u_quad_t\b/uint64_t/g;
s/\b(__)?quad_t\b/uint64_t/g;
' $(grep -lE -e '\<((__)?(quad_t|u(short|int|long|_(char|short|int([0-9]+_t)?|long|quad_t))))\>' \
$(grep -LE '\<(_(SYS|BITS)_TYPES_H|rpc/(rpc|rpc_msg|types|xdr)\.h)\>' \
$(find . \( -false $(sed 's/^/-o -name /' all-installed-headers) \
\) -printf '%P\n' | sort -u)))
where 'all-installed-headers' was a list of the basenames of all installed
header files, manually extracted from the Makefiles. Non-installed
wrapper headers in include/ are also adjusted, for consistency.
I then manually fixed up indentation and line-wrapping.
sys/types.h and bits/types.h are excluded because they must continue
to define the u_* types (under __USE_MISC) for compatibility with
applications. They do not use these types themselves.
All headers that (transitively) include rpc/types.h are also excluded,
for three reasons. First, the u_* types are defined by rpc/types.h,
unconditionally (not just under __USE_MISC) so they are logically part
of the SunRPC API. Second, many of those headers appear to be
machine-generated. Third, it's my understanding that we are getting
rid of as much of SunRPC as possible in the near future.
(The one file under sunrpc/ that's touched, sunrpc/rpc/rpc_des.h, does
*not* include rpc/types.h. This may itself be a bug.)
After changing from u_intNN_t to uintNN_t, a number of headers now
need to include stdint.h to pick up those types. It might be more
hygenic, namespace-wise, to use __uintNN_t instead, but none of these
headers are bound by ISO or POSIX to do so, and it's unlikely that
anyone using them will be bothered. (The two files that were using
__-prefixed versions of the u_types, sysdeps/mach/hurd/net/route.h and
sysdeps/unix/sysv/linux/net/route.h, both already also contained uses of
the unprefixed versions.)
Some of these files directly included features.h and/or sys/cdefs.h,
which I removed, as the style generally seems to be to let sys/types.h
do that for us. (This does not change the set of definitions exposed
by any header; sys/types.h unconditionally includes both features.h
and sys/cdefs.h.)
One file included asm/types.h unnecessarily.
* bits/in.h, gmon/sys/gmon.h, inet/netinet/igmp.h
* inet/protocols/routed.h, inet/protocols/talkd.h
* inet/protocols/timed.h, io/fts.h, nptl_db/thread_db.h
* resolv/arpa/nameser.h, resolv/resolv.h, sunrpc/rpc/rpc_des.h
* sysdeps/generic/netinet/if_ether.h
* sysdeps/generic/netinet/in_systm.h
* sysdeps/generic/netinet/ip.h, sysdeps/generic/netinet/tcp.h
* sysdeps/gnu/netinet/ip_icmp.h, sysdeps/gnu/netinet/tcp.h
* sysdeps/gnu/netinet/udp.h, sysdeps/mach/hurd/net/ethernet.h
* sysdeps/mach/hurd/net/if_arp.h
* sysdeps/mach/hurd/net/if_ppp.h
* sysdeps/mach/hurd/net/route.h, sysdeps/mach/sys/reboot.h
* sysdeps/unix/sysv/linux/bits/in.h
* sysdeps/unix/sysv/linux/net/ethernet.h
* sysdeps/unix/sysv/linux/net/if_arp.h
* sysdeps/unix/sysv/linux/net/if_ppp.h
* sysdeps/unix/sysv/linux/net/if_shaper.h
* sysdeps/unix/sysv/linux/net/route.h
* sysdeps/unix/sysv/linux/netinet/if_ether.h
* sysdeps/unix/sysv/linux/netinet/if_fddi.h
* sysdeps/unix/sysv/linux/netinet/if_tr.h
* sysdeps/unix/sysv/linux/netipx/ipx.h
* sysdeps/unix/sysv/linux/sys/acct.h
* include/arpa/nameser.h, include/resolv.h:
Change all uses of u_char to unsigned char,
u_short and ushort to unsigned short, u_int and uint to unsigned int,
u_long and ulong to unsigned long, u_int8_t to uint8_t,
u_int16_t to uint16_t, u_int32_t to uint32_t, quad_t to int64_t,
and u_int64_t and u_quad_t to uint64_t.
* mach/sys/reboot.h: Remove two casts of integer literals
to the types they already have.
* bits/in.h: Correct error in description of IP_MULTICAST_LOOP.
* sysdeps/unix/sysv/linux/bits/in.h: Likewise.
* sysdeps/unix/sysv/linux/netinet/if_ether.h: Change a comment
from referring to 'unsigned char' to 'uint8_t' for consistency with
the macro definition below.
* gmon/sys/gmon.h, inet/netinet/igmp.h, inet/protocols/talkd.h
* io/fts.h, resolv/arpa/nameser.h, resolv/resolv.h
* sunrpc/rpc/rpc_des.h, sysdeps/generic/netinet/ip.h
* sysdeps/gnu/netinet/tcp.h, sysdeps/gnu/netinet/udp.h
* sysdeps/mach/hurd/net/if_ppp.h, sysdeps/unix/sysv/linux/net/if_ppp.h
* sysdeps/unix/sysv/linux/sys/acct.h
* include/arpa/nameser.h, include/resolv.h:
Fix indentation disrupted by mechanical edits.
* inet/protocols/talkd.h, resolv/arpa/nameser.h
* sysdeps/generic/netinet/in_systm.h
* sysdeps/gnu/netinet/ip_icmp.h, sysdeps/gnu/netinet/tcp.h
* sysdeps/gnu/netinet/udp.h
* sysdeps/unix/sysv/linux/net/ethernet.h
* sysdeps/unix/sysv/linux/net/if_arp.h
* sysdeps/unix/sysv/linux/net/if_ppp.h
* sysdeps/unix/sysv/linux/net/if_shaper.h
* sysdeps/unix/sysv/linux/netinet/if_fddi.h
* sysdeps/unix/sysv/linux/netinet/if_tr.h
* sysdeps/unix/sysv/linux/netipx/ipx.h
* sysdeps/unix/sysv/linux/sys/acct.h
Include stdint.h for uintNN_t definitions.
Don't include sys/cdefs.h, features.h, or asm/types.h directly.
This patch adds the new UDP_ENCAP_GTP0 and UDP_ENCAP_GTP1U from Linux
4.7 to sysdeps/gnu/netinet/udp.h.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* sysdeps/gnu/netinet/udp.h (UDP_ENCAP_GTP0): New macro.
(UDP_ENCAP_GTP1U): Likewise.
In preparation to fix the --localedir configure argument we must
move the existing conflicting definition of localedir to a more
appropriate name. Given that all current internal uses of localedir
relate to the compiled locales we rename to complocaledir.
This patch adds move TCP_* values to sysdeps/gnu/netinet/tcp.h to
bring it up to date with Linux 4.2. TCP_SAVE_SYN and TCP_SAVED_SYN
are new in 4.2, TCP_NOTSENT_LOWAT and TCP_CC_INFO are older (Szabolcs
previously noted in
<https://sourceware.org/ml/libc-alpha/2015-06/msg00938.html> that this
header was out of date in glibc).
Tested for x86_64 (testsuite, and that installed stripped shared
libraries are unchanged by the patch).
* sysdeps/gnu/netinet/tcp.h (TCP_NOTSENT_LOWAT): New macro.
(TCP_CC_INFO): Likewise.
(TCP_SAVE_SYN): Likewise.
(TCP_SAVED_SYN): Likewise.
Various objects in glibc bring in ifaddrs.o (via references to
__netlink_*) and thereby getifaddrs and freeifaddrs, which are not
part of any standard supported by glibc. These should be weak aliases
of __getifaddrs and __freeifaddrs; this patch makes them so.
(The path by which these functions are brought in is Linux-specific,
but it seems less confusing to make all versions of these functions
weak aliases rather than only the Linux-specific versions that
definitely need it.)
Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by this patch).
[BZ #17668]
* inet/ifaddrs.c (getifaddrs): Rename to __getifaddrs and define
as weak alias of __getifaddrs. Use libc_hidden_weak.
(freeifaddrs): Rename to __freeifaddrs and define as weak alias of
__freeifaddrs. Use libc_hidden_weak.
* sysdeps/gnu/ifaddrs.c (getifaddrs): Rename to __getifaddrs and
define as weak alias of __getifaddrs. Use libc_hidden_weak.
(freeifaddrs): Rename to __freeifaddrs and define as weak alias of
__freeifaddrs. Use libc_hidden_weak.
* sysdeps/unix/sysv/linux/ifaddrs.c (getifaddrs): Rename to
__getifaddrs and define as weak alias of __getifaddrs. Use
libc_hidden_weak.
(freeifaddrs): Rename to __freeifaddrs and define as weak alias of
__freeifaddrs. Use libc_hidden_weak.
* conform/Makefile (test-xfail-XOPEN2K/net/if.h/linknamespace):
Remove variable.
(test-xfail-POSIX2008/net/if.h/linknamespace): Likewise.
(test-xfail-XOPEN2K8/net/if.h/linknamespace): Likewise.
The current scheme to identify which module a translation unit is
built in depends on defining multiple macros IS_IN_* and also defining
NOT_IN_libc if we're building a non-libc module. In addition, there
is an IN_LIB macro that does effectively the same thing, but for
different modules (notably the systemtap probes). This macro scheme
unifies both ideas to use just one macro IN_MODULE and assign it a
value depending on the module it is being built into. If the module
is not defined, it defaults to MODULE_libc.
Patches that follow will replace uses of IS_IN_* variables with the
IS_IN() macro. libc-symbols.h has been converted already to give an
example of how such a transition will look.
Verified that there are no relevant binary changes. One source change
that will crop up repeatedly is that of nscd_stat, since it uses the
build timestamp as a constant in its logic.
* Makeconfig (in-module): Get value of libof set for the
translation unit.
(CPPFLAGS): Use $(in-module).
* Makerules: Don't suffix routine names for nonlib.
* include/libc-modules.h: New file.
* include/libc-symbols.h: Include libc-modules.h
(IS_IN): New macro to replace IS_IN_* macros.
* elf/Makefile: Set libof-* for each routine.
* elf/rtld-Rules: Likewise.
* extra-modules.mk: Likewise.
* iconv/Makefile: Likewise.
* iconvdata/Makefile: Likewise.
* locale/Makefile: Likewise.
* malloc/Makefile: Likewise.
* nss/Makefile: Likewise.
* sysdeps/gnu/Makefile: Likewise.
* sysdeps/ieee754/ldbl-opt/Makefile: Likewise.
* sysdeps/unix/sysv/linux/Makefile: Likewise.
* sysdeps/s390/s390-64/Makefile: Likewise.
* nscd/Makefile: Set libof-* for each routine. Set CFLAGS and
CPPFLAGS for nscd instead of nonlib.
This patch adds the new constants UDP_NO_CHECK6_TX and
UDP_NO_CHECK6_RX from Linux 3.16 to sysdeps/gnu/netinet/udp.h. (I
believe the existing constants there are already Linux-specific,
possibly with the intention that other OSes should adopt the same
values if possible if adopting the features in question.)
Tested on x86_64.
* sysdeps/gnu/netinet/udp.h (UDP_NO_CHECK6_TX): New macro.
(UDP_NO_CHECK6_RX): Likewise.
