Fix resolver if_* namespace (bug 17717)

[Joseph Myers <joseph at codesourcery dot com>]

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).

2014-12-16  Joseph Myers  <joseph@codesourcery.com>

	[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.

diff --git a/conform/Makefile b/conform/Makefile
index 1933565..e0412de 100644
--- a/conform/Makefile
+++ b/conform/Makefile
@@ -359,10 +359,8 @@ test-xfail-XPG4/ctype.h/linknamespace = yes
 test-xfail-XPG4/fmtmsg.h/linknamespace = yes
 test-xfail-XPG4/fnmatch.h/linknamespace = yes
 test-xfail-XPG4/glob.h/linknamespace = yes
-test-xfail-XPG4/grp.h/linknamespace = yes
 test-xfail-XPG4/libgen.h/linknamespace = yes
 test-xfail-XPG4/netdb.h/linknamespace = yes
-test-xfail-XPG4/pwd.h/linknamespace = yes
 test-xfail-XPG4/regex.h/linknamespace = yes
 test-xfail-XPG4/search.h/linknamespace = yes
 test-xfail-XPG4/stdio.h/linknamespace = yes
@@ -381,24 +379,18 @@ test-xfail-POSIX/semaphore.h/linknamespace = yes
 test-xfail-POSIX/time.h/linknamespace = yes
 test-xfail-POSIX/unistd.h/linknamespace = yes
 test-xfail-POSIX/wordexp.h/linknamespace = yes
-test-xfail-UNIX98/aio.h/linknamespace = yes
 test-xfail-UNIX98/ctype.h/linknamespace = yes
 test-xfail-UNIX98/fmtmsg.h/linknamespace = yes
 test-xfail-UNIX98/fnmatch.h/linknamespace = yes
 test-xfail-UNIX98/glob.h/linknamespace = yes
-test-xfail-UNIX98/grp.h/linknamespace = yes
 test-xfail-UNIX98/libgen.h/linknamespace = yes
 test-xfail-UNIX98/mqueue.h/linknamespace = yes
 test-xfail-UNIX98/netdb.h/linknamespace = yes
-test-xfail-UNIX98/pthread.h/linknamespace = yes
-test-xfail-UNIX98/pwd.h/linknamespace = yes
 test-xfail-UNIX98/regex.h/linknamespace = yes
-test-xfail-UNIX98/sched.h/linknamespace = yes
 test-xfail-UNIX98/search.h/linknamespace = yes
 test-xfail-UNIX98/stdio.h/linknamespace = yes
 test-xfail-UNIX98/stdlib.h/linknamespace = yes
 test-xfail-UNIX98/syslog.h/linknamespace = yes
-test-xfail-UNIX98/time.h/linknamespace = yes
 test-xfail-UNIX98/unistd.h/linknamespace = yes
 test-xfail-UNIX98/wchar.h/linknamespace = yes
 test-xfail-UNIX98/wordexp.h/linknamespace = yes
diff --git a/include/net/if.h b/include/net/if.h
index 1d86226..6c4cbc9 100644
--- a/include/net/if.h
+++ b/include/net/if.h
@@ -4,9 +4,13 @@
 
 #ifndef _ISOMAC
 libc_hidden_proto (if_nametoindex)
+extern __typeof (if_nametoindex) __if_nametoindex;
+libc_hidden_proto (__if_nametoindex)
 libc_hidden_proto (if_indextoname)
 libc_hidden_proto (if_nameindex)
 libc_hidden_proto (if_freenameindex)
+extern __typeof (if_freenameindex) __if_freenameindex;
+libc_hidden_proto (__if_freenameindex)
 #endif
 
 #endif
diff --git a/inet/if_index.c b/inet/if_index.c
index 98b01d1..8b30d01 100644
--- a/inet/if_index.c
+++ b/inet/if_index.c
@@ -20,35 +20,40 @@
 #include <stddef.h>
 
 unsigned int
-if_nametoindex (const char *ifname)
+__if_nametoindex (const char *ifname)
 {
   __set_errno (ENOSYS);
   return 0;
 }
-libc_hidden_def (if_nametoindex)
+libc_hidden_def (__if_nametoindex)
+weak_alias (__if_nametoindex, if_nametoindex)
+libc_hidden_weak (if_nametoindex)
 stub_warning (if_nametoindex)
 
 char *
-if_indextoname (unsigned int ifindex, char *ifname)
+__if_indextoname (unsigned int ifindex, char *ifname)
 {
   __set_errno (ENOSYS);
   return NULL;
 }
-libc_hidden_def (if_indextoname)
+weak_alias (__if_indextoname, if_indextoname)
+libc_hidden_weak (if_indextoname)
 stub_warning (if_indextoname)
 
 void
-if_freenameindex (struct if_nameindex *ifn)
+__if_freenameindex (struct if_nameindex *ifn)
 {
 }
+weak_alias (__if_freenameindex, if_freenameindex)
 stub_warning (if_freenameindex)
 
 struct if_nameindex *
-if_nameindex (void)
+__if_nameindex (void)
 {
   __set_errno (ENOSYS);
   return NULL;
 }
+weak_alias (__if_nameindex, if_nameindex)
 stub_warning (if_nameindex)
 
 #if 0
diff --git a/resolv/res_init.c b/resolv/res_init.c
index 90760ec..6eddcdd 100644
--- a/resolv/res_init.c
+++ b/resolv/res_init.c
@@ -341,7 +341,7 @@ __res_vinit(res_state statp, int preinit) {
 				    if (IN6_IS_ADDR_LINKLOCAL (&a6)
 					|| IN6_IS_ADDR_MC_LINKLOCAL (&a6)) {
 					sa6->sin6_scope_id
-					  = if_nametoindex (el + 1);
+					  = __if_nametoindex (el + 1);
 					if (sa6->sin6_scope_id != 0)
 					    try_numericscope = 0;
 				    }
diff --git a/sysdeps/mach/hurd/if_index.c b/sysdeps/mach/hurd/if_index.c
index 9d0ca62..11d2114 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
diff --git a/sysdeps/unix/sysv/linux/if_index.c b/sysdeps/unix/sysv/linux/if_index.c
index 0fac763..b0644f2 100644
--- a/sysdeps/unix/sysv/linux/if_index.c
+++ b/sysdeps/unix/sysv/linux/if_index.c
@@ -31,7 +31,7 @@
 
 
 unsigned int
-if_nametoindex (const char *ifname)
+__if_nametoindex (const char *ifname)
 {
 #ifndef SIOCGIFINDEX
   __set_errno (ENOSYS);
@@ -56,11 +56,13 @@ if_nametoindex (const char *ifname)
   return ifr.ifr_ifindex;
 #endif
 }
-libc_hidden_def (if_nametoindex)
+libc_hidden_def (__if_nametoindex)
+weak_alias (__if_nametoindex, if_nametoindex)
+libc_hidden_weak (if_nametoindex)
 
 
 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)
@@ -70,7 +72,9 @@ if_freenameindex (struct if_nameindex *ifn)
     }
   free (ifn);
 }
-libc_hidden_def (if_freenameindex)
+libc_hidden_def (__if_freenameindex)
+weak_alias (__if_freenameindex, if_freenameindex)
+libc_hidden_weak (if_freenameindex)
 
 
 static struct if_nameindex *
@@ -162,7 +166,7 @@ if_nameindex_netlink (void)
 		      if (idx[nifs].if_name == NULL)
 			{
 			  idx[nifs].if_index = 0;
-			  if_freenameindex (idx);
+			  __if_freenameindex (idx);
 			  idx = NULL;
 			  goto nomem;
 			}
@@ -189,7 +193,7 @@ if_nameindex_netlink (void)
 
 
 struct if_nameindex *
-if_nameindex (void)
+__if_nameindex (void)
 {
 #ifndef SIOCGIFINDEX
   __set_errno (ENOSYS);
@@ -199,11 +203,12 @@ if_nameindex (void)
   return result;
 #endif
 }
-libc_hidden_def (if_nameindex)
+weak_alias (__if_nameindex, if_nameindex)
+libc_hidden_weak (if_nameindex)
 
 
 char *
-if_indextoname (unsigned int ifindex, char *ifname)
+__if_indextoname (unsigned int ifindex, char *ifname)
 {
   /* We may be able to do the conversion directly, rather than searching a
      list.  This ioctl is not present in kernels before version 2.1.50.  */
@@ -232,4 +237,5 @@ if_indextoname (unsigned int ifindex, char *ifname)
   else
     return strncpy (ifname, ifr.ifr_name, IFNAMSIZ);
 }
-libc_hidden_def (if_indextoname)
+weak_alias (__if_indextoname, if_indextoname)
+libc_hidden_weak (if_indextoname)

-- 
Joseph S. Myers
joseph@codesourcery.com