glibc/inet/gethstbyad_r.c
Joseph Myers 17c199ee92 Fix gethostbyaddr in6addr_any, in6addr_loopback namespace (bug 18532).
gethostbyaddr brings in references to in6addr_any and thereby
in6addr_loopback, which aren't in all the standards containing
gethostbyaddr (gethostbyaddr is in XPG4 and UNIX98, in6addr_any and
in6addr_loopback are new in POSIX.1:2001).  This patch fixes this by
making those symbols into weak aliases (safe in this case, unlike for
most data symbols, because these data symbols are const).

Tested for x86_64 and x86 (testsuite, and comparison of disassembly of
installed stripped shared libraries).  Disassembly is unchanged for
x86_64; for x86, I see some changes of stack offsets, but no other
code generation changes or code size differences.

	[BZ #18532]
	* inet/in6_addr.c (in6addr_any): Rename to __in6addr_any and
	define as weak alias of __in6addr_any.  Use libc_hidden_data_weak.
	(in6addr_loopback): Rename to __in6addr_loopback and define as
	weak alias of __in6addr_loopback.  Use libc_hidden_data_weak.
	* include/netinet/in.h (__in6addr_loopback): Declare.  Use
	libc_hidden_proto.
	(__in6addr_any): Likewise.
	* inet/gethstbyad_r.c (PREPROCESS): Use __in6addr_any instead of
	in6addr_any.
	* conform/Makefile (test-xfail-XPG4/netdb.h/linknamespace): Remove
	variable.
	(test-xfail-UNIX98/netdb.h/linknamespace): Likewise.
2015-06-17 20:08:22 +00:00

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1.9 KiB
C

/* Copyright (C) 1996-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <netdb.h>
#include <string.h>
#define LOOKUP_TYPE struct hostent
#define FUNCTION_NAME gethostbyaddr
#define DATABASE_NAME hosts
#define ADD_PARAMS const void *addr, socklen_t len, int type
#define ADD_VARIABLES addr, len, type
#define NEED_H_ERRNO 1
#define NEED__RES 1
#define NEED__RES_HCONF 1
/* If the addr parameter is the IPv6 unspecified address no query must
be performed. */
#define PREPROCESS \
if (len == sizeof (struct in6_addr) \
&& __builtin_expect (memcmp (&__in6addr_any, addr, \
sizeof (struct in6_addr)), 1) == 0) \
{ \
*h_errnop = HOST_NOT_FOUND; \
*result = NULL; \
return ENOENT; \
}
#define POSTPROCESS \
if (status == NSS_STATUS_SUCCESS) \
{ \
_res_hconf_reorder_addrs (resbuf); \
_res_hconf_trim_domains (resbuf); \
}
/* Special name for the lookup function. */
#define DB_LOOKUP_FCT __nss_hosts_lookup2
#include "../nss/getXXbyYY_r.c"