Fix resolver if_* namespace (bug 17717).

Resolver code, brought in by pthreads (at least), uses if_* interfaces
that weren't in POSIX before 2001, resulting in linknamespace
failures.  This patch changes those interfaces to be weak aliases of
__if_* and makes the resolver use __if_* directly.

Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by this patch).

	[BZ #17717]
	* inet/if_index.c (if_nametoindex): Rename to __if_nametoindex and
	define as weak alias of __if_nametoindex.  Use libc_hidden_weak.
	(if_indextoname): Rename to __if_indextoname and define as weak
	alias of __if_indextoname.  Use libc_hidden_weak.
	(if_freenameindex): Rename to __if_freenameindex and define as
	weak alias of __if_freenameindex.
	(if_nameindex): Rename to __if_nameindex and define as weak alias
	of __if_nameindex.
	* sysdeps/mach/hurd/if_index.c (if_nametoindex): Rename to
	__if_nametoindex and define as weak alias of __if_nametoindex.
	Use libc_hidden_weak.
	(if_freenameindex): Rename to __if_freenameindex and define as
	weak alias of __if_freenameindex.
	(if_nameindex): Rename to __if_nameindex and define as weak alias
	of __if_nameindex.
	(if_indextoname): Rename to __if_indextoname and define as weak
	alias of __if_indextoname.  Use libc_hidden_weak.
	* sysdeps/unix/sysv/linux/if_index.c (if_nametoindex): Rename to
	__if_nametoindex and define as weak alias of __if_nametoindex.
	Use libc_hidden_weak.
	(if_freenameindex): Rename to __if_freenameindex and define as
	weak alias of __if_freenameindex.  Use libc_hidden_weak.
	(if_nameindex_netlink): Use __if_freenameindex instead of
	if_freenameindex.
	(if_nameindex): Rename to __if_nameindex and define as weak alias
	of __if_nameindex.  Use libc_hidden_weak.
	(if_indextoname): Rename to __if_indextoname and define as weak
	alias of __if_indextoname.  Use libc_hidden_weak.
	* include/net/if.h [!_ISOMAC] (__if_nametoindex): Declare and use
	libc_hidden_proto.
	[!_ISOMAC] (__if_freenameindex): Likewise.
	* resolv/res_init.c (__res_vinit): Use __if_nametoindex instead of
	if_nametoindex.
	* conform/Makefile (test-xfail-XPG4/grp.h/linknamespace): Remove
	variable.
	(test-xfail-XPG4/pwd.h/linknamespace): Likewise.
	(test-xfail-UNIX98/aio.h/linknamespace): Likewise.
	(test-xfail-UNIX98/grp.h/linknamespace): Likewise.
	(test-xfail-UNIX98/pthread.h/linknamespace): Likewise.
	(test-xfail-UNIX98/pwd.h/linknamespace): Likewise.
	(test-xfail-UNIX98/sched.h/linknamespace): Likewise.
	(test-xfail-UNIX98/time.h/linknamespace): Likewise.

1 files changed, 11 insertions, 6 deletions

diff --git a/sysdeps/mach/hurd/if_index.c b/sysdeps/mach/hurd/if_index.c
index 9d0ca62fa1..11d21146ae 100644
--- a/sysdeps/mach/hurd/if_index.c
+++ b/sysdeps/mach/hurd/if_index.c
@@ -29,7 +29,7 @@
 /* Return the interface index corresponding to interface IFNAME.
    On error, return 0.  */
 unsigned int
-if_nametoindex (const char *ifname)
+__if_nametoindex (const char *ifname)
 {
   struct ifreq ifr;
   int fd = __opensock ();
@@ -49,11 +49,13 @@ if_nametoindex (const char *ifname)
   __close (fd);
   return ifr.ifr_ifindex;
 }
-libc_hidden_def (if_nametoindex)
+libc_hidden_def (__if_nametoindex)
+weak_alias (__if_nametoindex, if_nametoindex)
+libc_hidden_weak (if_nametoindex)
 
 /* Free the structure IFN returned by if_nameindex.  */
 void
-if_freenameindex (struct if_nameindex *ifn)
+__if_freenameindex (struct if_nameindex *ifn)
 {
   struct if_nameindex *ptr = ifn;
   while (ptr->if_name || ptr->if_index)
@@ -63,12 +65,13 @@ if_freenameindex (struct if_nameindex *ifn)
     }
   free (ifn);
 }
+weak_alias (__if_freenameindex, if_freenameindex)
 
 /* Return an array of if_nameindex structures, one for each network
    interface present, plus one indicating the end of the array.  On
    error, return NULL.  */
 struct if_nameindex *
-if_nameindex (void)
+__if_nameindex (void)
 {
   error_t err = 0;
   char data[2048];
@@ -148,12 +151,13 @@ if_nameindex (void)
   __set_errno (err);
   return idx;
 }
+weak_alias (__if_nameindex, if_nameindex)
 
 /* Store the name of the interface corresponding to index IFINDEX in
    IFNAME (which has space for at least IFNAMSIZ characters).  Return
    IFNAME, or NULL on error.  */
 char *
-if_indextoname (unsigned int ifindex, char *ifname)
+__if_indextoname (unsigned int ifindex, char *ifname)
 {
   struct ifreq ifr;
   int fd = __opensock ();
@@ -175,7 +179,8 @@ if_indextoname (unsigned int ifindex, char *ifname)
   __close (fd);
   return strncpy (ifname, ifr.ifr_name, IFNAMSIZ);
 }
-libc_hidden_def (if_indextoname)
+weak_alias (__if_indextoname, if_indextoname)
+libc_hidden_weak (if_indextoname)
 
 #if 0
 void