login: Remove utmp backend jump tables [BZ #23518]

There is just one file-based implementation, so this dispatch
mechanism is unnecessary.  Instead of the vtable pointer
__libc_utmp_jump_table, use a non-negative file_fd as the indicator
that the backend is initialized.

1 files changed, 4 insertions, 104 deletions

diff --git a/login/getutent_r.c b/login/getutent_r.c
index 98ffc5d1c6..fd13be8a1e 100644
--- a/login/getutent_r.c
+++ b/login/getutent_r.c
@@ -23,115 +23,16 @@
 
 #include "utmp-private.h"
 
-
-/* Functions defined here.  */
-static int setutent_unknown (void);
-static int getutent_r_unknown (struct utmp *buffer, struct utmp **result);
-static int getutid_r_unknown (const struct utmp *line, struct utmp *buffer,
-			      struct utmp **result);
-static int getutline_r_unknown (const struct utmp *id, struct utmp *buffer,
-				struct utmp **result);
-static struct utmp *pututline_unknown (const struct utmp *data);
-static void endutent_unknown (void);
-
-/* Initial Jump table.  */
-const struct utfuncs __libc_utmp_unknown_functions =
-{
-  setutent_unknown,
-  getutent_r_unknown,
-  getutid_r_unknown,
-  getutline_r_unknown,
-  pututline_unknown,
-  endutent_unknown,
-  NULL
-};
-
-/* Currently selected backend.  */
-const struct utfuncs *__libc_utmp_jump_table = &__libc_utmp_unknown_functions;
-
 /* We need to protect the opening of the file.  */
 __libc_lock_define_initialized (, __libc_utmp_lock attribute_hidden)
 
 
-static int
-setutent_unknown (void)
-{
-  int result;
-
-  result = (*__libc_utmp_file_functions.setutent) ();
-  if (result)
-    __libc_utmp_jump_table = &__libc_utmp_file_functions;
-
-  return result;
-}
-
-
-static int
-getutent_r_unknown (struct utmp *buffer, struct utmp **result)
-{
-  /* The backend was not yet initialized.  */
-  if (setutent_unknown ())
-    return (*__libc_utmp_jump_table->getutent_r) (buffer, result);
-
-  /* Not available.  */
-  *result = NULL;
-  return -1;
-}
-
-
-static int
-getutid_r_unknown (const struct utmp *id, struct utmp *buffer,
-		   struct utmp **result)
-{
-  /* The backend was not yet initialized.  */
-  if (setutent_unknown ())
-    return (*__libc_utmp_jump_table->getutid_r) (id, buffer, result);
-
-  /* Not available.  */
-  *result = NULL;
-  return -1;
-}
-
-
-static int
-getutline_r_unknown (const struct utmp *line, struct utmp *buffer,
-		     struct utmp **result)
-{
-  /* The backend was not yet initialized.  */
-  if (setutent_unknown ())
-    return (*__libc_utmp_jump_table->getutline_r) (line, buffer, result);
-
-  /* Not available.  */
-  *result = NULL;
-  return -1;
-}
-
-
-static struct utmp *
-pututline_unknown (const struct utmp *data)
-{
-  /* The backend was not yet initialized.  */
-  if (setutent_unknown ())
-    return (*__libc_utmp_jump_table->pututline) (data);
-
-  /* Not available.  */
-  return NULL;
-}
-
-
-static void
-endutent_unknown (void)
-{
-  /* Nothing to do.  */
-}
-
-
 void
 __setutent (void)
 {
   __libc_lock_lock (__libc_utmp_lock);
 
-  (*__libc_utmp_jump_table->setutent) ();
+  __libc_setutent ();
 
   __libc_lock_unlock (__libc_utmp_lock);
 }
@@ -145,7 +46,7 @@ __getutent_r (struct utmp *buffer, struct utmp **result)
 
   __libc_lock_lock (__libc_utmp_lock);
 
-  retval = (*__libc_utmp_jump_table->getutent_r) (buffer, result);
+  retval = __libc_getutent_r (buffer, result);
 
   __libc_lock_unlock (__libc_utmp_lock);
 
@@ -162,7 +63,7 @@ __pututline (const struct utmp *data)
 
   __libc_lock_lock (__libc_utmp_lock);
 
-  buffer = (*__libc_utmp_jump_table->pututline) (data);
+  buffer = __libc_pututline (data);
 
   __libc_lock_unlock (__libc_utmp_lock);
 
@@ -177,8 +78,7 @@ __endutent (void)
 {
   __libc_lock_lock (__libc_utmp_lock);
 
-  (*__libc_utmp_jump_table->endutent) ();
-  __libc_utmp_jump_table = &__libc_utmp_unknown_functions;
+  __libc_endutent ();
 
   __libc_lock_unlock (__libc_utmp_lock);
 }