(if_indextoname): Correct error value for unknown interface.

diff --git a/sysdeps/unix/sysv/linux/if_index.c b/sysdeps/unix/sysv/linux/if_index.c
index 9922ced..76349bd 100644 (file)
--- a/sysdeps/unix/sysv/linux/if_index.c
+++ b/sysdeps/unix/sysv/linux/if_index.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1997,98,99,2000,2002,2003 Free Software Foundation, Inc.
+/* Copyright (C) 1997,98,99,2000,2002,2003,2004 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
@@ -211,18 +211,26 @@ if_indextoname (unsigned int ifindex, char *ifname)
 
       close_not_cancel_no_status (fd);
 
-#  if __ASSUME_SIOCGIFNAME == 0
       if (status  < 0)
        {
+#  if __ASSUME_SIOCGIFNAME == 0
          if (errno == EINVAL)
            siocgifname_works_not = 1; /* Don't make the same mistake twice. */
+         else
+#  endif
+           {
+             if (errno == ENODEV)
+               /* POSIX requires ENXIO.  */
+               __set_errno (ENXIO);
+
+             return NULL;
+           }
        }
       else
        return strncpy (ifname, ifr.ifr_name, IFNAMSIZ);
 
+#  if __ASSUME_SIOCGIFNAME == 0
       __set_errno (serrno);
-#  else
-      return status < 0 ? NULL : strncpy (ifname, ifr.ifr_name, IFNAMSIZ);
 #  endif
     }
 # endif
@@ -240,6 +248,9 @@ if_indextoname (unsigned int ifindex, char *ifname)
          }
 
       if_freenameindex (idx);
+
+      if (result == NULL)
+       __set_errno (ENXIO);
     }
   return result;
 # endif