inet: Make IN6_IS_ADDR_UNSPECIFIED etc. usable with POSIX [BZ #16421]

Previously, under some feature test macros and compilers, the
macros were defined, but references undefined struct members
in their implementation.

4 files changed, 49 insertions, 27 deletions

diff --git a/inet/Makefile b/inet/Makefile
index 1c30932997..c82ad924aa 100644
--- a/inet/Makefile
+++ b/inet/Makefile
@@ -51,8 +51,8 @@ aux := check_pf check_native ifreq
 
 tests := htontest test_ifindex tst-ntoa tst-ether_aton tst-network \
 	 tst-gethnm test-ifaddrs bug-if1 test-inet6_opt tst-ether_line \
-	 tst-getni1 tst-getni2 tst-inet6_rth tst-checks tst-sockaddr \
-	 tst-inet6_scopeid_pton
+	 tst-getni1 tst-getni2 tst-inet6_rth tst-checks tst-checks-posix \
+	 tst-sockaddr tst-inet6_scopeid_pton
 
 include ../Rules
 
@@ -86,6 +86,7 @@ CFLAGS-either_hton.c = -fexceptions
 CFLAGS-getnetgrent.c = -fexceptions
 CFLAGS-getnetgrent_r.c = -fexceptions
 
+CFLAGS-tst-checks-posix.c = -std=c99
 CFLAGS-tst-sockaddr.c = -fno-strict-aliasing
 
 endif
diff --git a/inet/netinet/in.h b/inet/netinet/in.h
index c801593b32..01594c6aec 100644
--- a/inet/netinet/in.h
+++ b/inet/netinet/in.h
@@ -213,10 +213,8 @@ struct in6_addr
     union
       {
 	uint8_t	__u6_addr8[16];
-#ifdef __USE_MISC
 	uint16_t __u6_addr16[8];
 	uint32_t __u6_addr32[4];
-#endif
       } __in6_u;
 #define s6_addr			__in6_u.__u6_addr8
 #ifdef __USE_MISC
@@ -411,52 +409,52 @@ extern uint16_t htons (uint16_t __hostshort)
 # define IN6_IS_ADDR_UNSPECIFIED(a) \
   (__extension__							      \
    ({ const struct in6_addr *__a = (const struct in6_addr *) (a);	      \
-      __a->s6_addr32[0] == 0						      \
-      && __a->s6_addr32[1] == 0						      \
-      && __a->s6_addr32[2] == 0						      \
-      && __a->s6_addr32[3] == 0; }))
+      __a->__in6_u.__u6_addr32[0] == 0					      \
+      && __a->__in6_u.__u6_addr32[1] == 0				      \
+      && __a->__in6_u.__u6_addr32[2] == 0				      \
+      && __a->__in6_u.__u6_addr32[3] == 0; }))
 
 # define IN6_IS_ADDR_LOOPBACK(a) \
   (__extension__							      \
    ({ const struct in6_addr *__a = (const struct in6_addr *) (a);	      \
-      __a->s6_addr32[0] == 0						      \
-      && __a->s6_addr32[1] == 0						      \
-      && __a->s6_addr32[2] == 0						      \
-      && __a->s6_addr32[3] == htonl (1); }))
+      __a->__in6_u.__u6_addr32[0] == 0					      \
+      && __a->__in6_u.__u6_addr32[1] == 0				      \
+      && __a->__in6_u.__u6_addr32[2] == 0				      \
+      && __a->__in6_u.__u6_addr32[3] == htonl (1); }))
 
 # define IN6_IS_ADDR_LINKLOCAL(a) \
   (__extension__							      \
    ({ const struct in6_addr *__a = (const struct in6_addr *) (a);	      \
-      (__a->s6_addr32[0] & htonl (0xffc00000)) == htonl (0xfe800000); }))
+      (__a->__in6_u.__u6_addr32[0] & htonl (0xffc00000)) == htonl (0xfe800000); }))
 
 # define IN6_IS_ADDR_SITELOCAL(a) \
   (__extension__							      \
    ({ const struct in6_addr *__a = (const struct in6_addr *) (a);	      \
-      (__a->s6_addr32[0] & htonl (0xffc00000)) == htonl (0xfec00000); }))
+      (__a->__in6_u.__u6_addr32[0] & htonl (0xffc00000)) == htonl (0xfec00000); }))
 
 # define IN6_IS_ADDR_V4MAPPED(a) \
   (__extension__							      \
    ({ const struct in6_addr *__a = (const struct in6_addr *) (a);	      \
-      __a->s6_addr32[0] == 0						      \
-      && __a->s6_addr32[1] == 0						      \
-      && __a->s6_addr32[2] == htonl (0xffff); }))
+      __a->__in6_u.__u6_addr32[0] == 0					      \
+      && __a->__in6_u.__u6_addr32[1] == 0				      \
+      && __a->__in6_u.__u6_addr32[2] == htonl (0xffff); }))
 
 # define IN6_IS_ADDR_V4COMPAT(a) \
   (__extension__							      \
    ({ const struct in6_addr *__a = (const struct in6_addr *) (a);	      \
-      __a->s6_addr32[0] == 0						      \
-      && __a->s6_addr32[1] == 0						      \
-      && __a->s6_addr32[2] == 0						      \
-      && ntohl (__a->s6_addr32[3]) > 1; }))
+      __a->__in6_u.__u6_addr32[0] == 0					      \
+      && __a->__in6_u.__u6_addr32[1] == 0				      \
+      && __a->__in6_u.__u6_addr32[2] == 0				      \
+      && ntohl (__a->__in6_u.__u6_addr32[3]) > 1; }))
 
 # define IN6_ARE_ADDR_EQUAL(a,b) \
   (__extension__							      \
    ({ const struct in6_addr *__a = (const struct in6_addr *) (a);	      \
       const struct in6_addr *__b = (const struct in6_addr *) (b);	      \
-      __a->s6_addr32[0] == __b->s6_addr32[0]				      \
-      && __a->s6_addr32[1] == __b->s6_addr32[1]				      \
-      && __a->s6_addr32[2] == __b->s6_addr32[2]				      \
-      && __a->s6_addr32[3] == __b->s6_addr32[3]; }))
+      __a->__in6_u.__u6_addr32[0] == __b->__in6_u.__u6_addr32[0]	      \
+      && __a->__in6_u.__u6_addr32[1] == __b->__in6_u.__u6_addr32[1]	      \
+      && __a->__in6_u.__u6_addr32[2] == __b->__in6_u.__u6_addr32[2]	      \
+      && __a->__in6_u.__u6_addr32[3] == __b->__in6_u.__u6_addr32[3]; }))
 #else
 # define IN6_IS_ADDR_UNSPECIFIED(a) \
 	(((const uint32_t *) (a))[0] == 0				      \
diff --git a/inet/tst-checks-posix.c b/inet/tst-checks-posix.c
new file mode 100644
index 0000000000..c41a180bf5
--- /dev/null
+++ b/inet/tst-checks-posix.c
@@ -0,0 +1,24 @@
+/* Test IPv6 classification macros in POSIX mode.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+/* Process tst-checks.c in POSIX mode.  */
+#undef _GNU_SOURCE
+#define _POSIX_C_SOURCE 200112L
+#define _ISOMAC
+
+#include "tst-checks.c"
diff --git a/inet/tst-checks.c b/inet/tst-checks.c
index 5d97564cd6..1a4785d96e 100644
--- a/inet/tst-checks.c
+++ b/inet/tst-checks.c
@@ -169,5 +169,4 @@ do_test (void)
   return result;
 }
 
-#define TEST_FUNCTION do_test ()
-#include "../test-skeleton.c"
+#include <support/test-driver.c>