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authorUlrich Drepper <drepper@redhat.com>1998-04-20 18:41:05 +0000
committerUlrich Drepper <drepper@redhat.com>1998-04-20 18:41:05 +0000
commit8619129f3f0d5a9db6208be5bae6c2a8c9ce61a5 (patch)
tree033b6528f39a85f12db9d0859dbd1b90c2906eee /sysdeps/generic/utmp_file.c
parentf1fa8b68f3e7623a3ef86dcd0c7d090ccf0389f5 (diff)
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Update.
1998-04-20 18:00  Ulrich Drepper  <drepper@cygnus.com>

	* libc.map: Add __dgettext to GLIBC_2.0 and __libc_longjmp, and
	__libc_siglongjmp to GLIBC_2.1.

	* elf/dl-minimal.c (__assert_perror_fail): Don't use strerror, use
	__strerror_r.

	* iconv/Makefile: Don't run tests now.

	* iconv/iconv_prog.c (process_block): If loop is repeated, call iconv
	with correct output buffer.

	Major rewrite of the low-level gconv functionality.
	* iconv/gconv.c: Rewritten.
	* iconv/gconv.h: Likewise.
	* iconv/gconv_builtin.c: Likewise.
	* iconv/gconv_builtin.h: Likewise.
	* iconv/gconv_conf.c: Likewise.
	* iconv/gconv_int.h: Likewise.
	* iconv/gconv_open.c: Likewise.
	* iconv/gconv_simple.c: Likewise.
	* iconv/iconv.c: Likewise.
	* iconvdata/8bit-gap.c: Likewise.
	* iconvdata/8bit-generic.c: Likewise.
	* iconvdata/Makefile: Likewise.
	* iconvdata/big5.c: Likewise.
	* iconvdata/cns11643.c: Likewise.
	* iconvdata/cns11643.h: Likewise.
	* iconvdata/cns11643l1.c: Likewise.
	* iconvdata/cns11643l1.h: Likewise.
	* iconvdata/ebcdic-at-de-a.c: Likewise.
	* iconvdata/ebcdic-at-de.c: Likewise.
	* iconvdata/ebcdic-ca-fr.c: Likewise.
	* iconvdata/euccn.c: Likewise.
	* iconvdata/eucjp.c: Likewise.
	* iconvdata/euckr.c: Likewise.
	* iconvdata/euctw.c: Likewise.
	* iconvdata/gb2312.c: Likewise.
	* iconvdata/gb2312.h: Likewise.
	* iconvdata/hp-roman8.c: Likewise.
	* iconvdata/iso646.c: Likewise.
	* iconvdata/iso6937.c: Likewise.
	* iconvdata/iso8859-1.c: Likewise.
	* iconvdata/iso8859-10.c: Likewise.
	* iconvdata/iso8859-2.c: Likewise.
	* iconvdata/iso8859-3.c: Likewise.
	* iconvdata/iso8859-4.c: Likewise.
	* iconvdata/iso8859-5.c: Likewise.
	* iconvdata/iso8859-6.c: Likewise.
	* iconvdata/iso8859-7.c: Likewise.
	* iconvdata/iso8859-8.c: Likewise.
	* iconvdata/iso8859-9.c: Likewise.
	* iconvdata/jis0201.c: Likewise.
	* iconvdata/jis0201.h: Likewise.
	* iconvdata/jis0208.c: Likewise.
	* iconvdata/jis0208.h: Likewise.
	* iconvdata/jis0212.c: Likewise.
	* iconvdata/jis0212.h: Likewise.
	* iconvdata/johab.c: Likewise.
	* iconvdata/koi-8.c: Likewise.
	* iconvdata/koi8-r.c: Likewise.
	* iconvdata/ksc5601.c: Likewise.
	* iconvdata/ksc5601.h: Likewise.
	* iconvdata/latin-greek-1.c: Likewise.
	* iconvdata/latin-greek.c: Likewise.
	* iconvdata/run-iconv-test.sh: Likewise.
	* iconvdata/sjis.c: Likewise.
	* iconvdata/t61.c: Likewise.
	* iconvdata/uhc.c: Likewise.
	* wcsmbs/btowc.c: Likewise.
	* wcsmbs/mbrtowc.c: Likewise.
	* wcsmbs/mbsnrtowcs.c: Likewise.
	* wcsmbs/mbsrtowcs.c: Likewise.
	* wcsmbs/wcrtomb.c: Likewise.
	* wcsmbs/wcsmbsload.c: Likewise.
	* wcsmbs/wcsnrtombs.c: Likewise.
	* wcsmbs/wcsrtombs.c: Likewise.
	* wcsmbs/wctob.c: Likewise.
	* iconv/loop.c: New file.
	* iconv/skeleton.c: New file.

	* stdlib/mblen.c: Handle empty input string correctly.
	* stdlib/mbtowc.c: Likewise.

	* posix/getopt.c: Various cleanups.

	* sysdeps/arm/bits/setjmp.h: Add copyright text.
	* sysdeps/i386/bits/setjmp.h: Likewise.
	* sysdeps/m68k/bits/setjmp.h: Likewise.
	* sysdeps/powerpc/bits/setjmp.h: Likewise.
	* sysdeps/sparc/sparc32/bits/setjmp.h: Likewise.

	* sysdeps/generic/longjmp.c: Rename function to __libc_siglongjmp
	and make longjmp weak alias.

1998-04-18 20:29  Philip Blundell  <Philip.Blundell@pobox.com>

	* iconv/Makefile (routines): Only include gconv_dl if building for
	an ELF system - dynamic linking is not available on a.out.
	(CFLAGS-gconv_conf.c): Define STATIC_GCONV if omitting gconv_dl
	due to above check.
	* iconv/gconv_db.c: If STATIC_GCONV defined, don't try to call
	routines from gconv_dl.

1998-04-17  Gordon Matzigkeit  <gord@profitpress.com>

	* csu/init.c (_IO_stdin_used): Protect with USE_IN_LIBIO so that
	we can compile without libio.

1998-04-20 16:28  Ulrich Drepper  <drepper@cygnus.com>

	* sysdeps/mach/hurd/Subdirs: Remove login.

1998-04-11  Gordon Matzigkeit  <gord@profitpress.com>

	* db2/compat.h: Include <errno.h>, to make sure we get the
	definition of EFTYPE before we define it ourselves.

1998-04-10  Gordon Matzigkeit  <gord@profitpress.com>

	* sysdeps/generic/bits/socket.h: Protect against multiple inclusion.
	* sysdeps/mach/hurd/bits/ioctls.h: Likewise.
	Fix typo to allow inclusion from sys/ioctl.h again.

1998-04-16  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* iconvdata/*.[ch]: Clean up namespace.  Optimize character lookup.

1998-04-16  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* libc.map: Export __strerror_r.  Remove _strerror_internal.

1998-04-16  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/generic/strcasestr.c: Undefine strcasestr, not strstr.
	Also undefine __strcasestr.

1998-04-16  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* posix/regex.c: Rename __re_max_failures back to re_max_failures,
	aliases do not work with global variables due to copy relocations.

1998-04-20 15:12  Ulrich Drepper  <drepper@cygnus.com>

	* manual/creature.texi: Fix type.  Patch by Andreas Schwab.

1998-04-20 13:47  Ulrich Drepper  <drepper@cygnus.com>

	* signal/sighold.c: Include stddef.h for NULL definition.
	* signal/sigrelse.c: Likewise.
	* sysdeps/posix/sigignore.c: Likewise.
	* sysdeps/posix/sigset.c: Likewise.
	* sysdeps/posix/waitid.c: Likewise.
	* sysdeps/unix/sysv/linux/rt_sigsuspend.c: Likewise.
	* sysdeps/unix/sysv/linux/rt_sigtimedwait.c: Likewise.
	* sysdeps/unix/sysv/linux/sigwaitinfo.c: Likewise.
	* wcsmbs/mbsrtowcs.c: Include stdlib.h for MB_CUR_MAX.
	Patch by Franz Sirl <Franz.Sirl-kernel@lauterbach.com>.

1998-04-13  Mark Kettenis  <kettenis@phys.uva.nl>

	* login/Makefile (headers): Remove utmpx.h and bits/utmpx.h.
	* login/getutent.c (getutxent): Remove alias.
	* login/getutent_r.c (setutxent, pututxline, endutxent):
	Remove aliases.
	* login/getutid.c (getutxid): Remove alias.
	* login/getutline.c (getutxline): Remove alias.
	* login/utmp.h: Add prototypes for __updwtmp, __getutent,
	__getutid, __getutline and __pututline.
	* login/utmpx.h: Moved to ...
	* sysdeps/gnu/utmpx.h: ... here.  [__USE_GNU]: Define UTMPX_FILE,
	UTMPX_FILENAME, WTMPX_FILE and WTMPX_FILENAME, declare utmpxname
	and updwtmpx.
	* login/updwtmp.c: Moved to ...
	* sysdeps/generic/updwtmp.c: ... here.  (updwtmp): Generalized by
	allowing file name transformation.
	* sysdeps/gnu/updwtmp.c: New file.  Use generic implementation with
	additional file name transformation.
	* sysdeps/unix/sysv/linux/updwtmp.c: Likewise.
	* login/utmp_file.c: Moved to ...
	* sysdeps/generic/utmp_file.c: ... here.  (setutent_file):
	Generalized by allowing file name transformation.  Do not
	print error message.  Library functions should not print them.
	Reported by Jim Meyering.
	* sysdeps/gnu/utmp_file.c: New file.  Use generic implementation
	with additional file name transformation.
	* sysdeps/unix/sysv/linux/utmp_file.c: Likewise.
	* sysdeps/gnu/Makefile [$(subdir)=login] (sysdep_routines): Add
	setutxent, getutxent, endutxent, getutxid, getutxid, getutxline,
	pututxline, utmpxname and updwtmpx.  (sysdep_headers): Add utmpx.h
	and bits/utmpx.h.
	* sysdeps/gnu/bits/utmpx.h [__USE_GNU] Include paths.h.
	(_PATH_UTMPX): Define to _PATH_UTMP.  (_PATH_WTMPX): Define to
	_PATH_WTMPX.  (RUN_LVL): Define only if __USE_GNU.  (ACCOUNTING):
	Define if __USE_GNU.
	* sysdeps/gnu/setutxent.c: New file.
	* sysdeps/gnu/getutxent.c: New file.
	* sysdeps/gnu/endutxent.c: New file.
	* sysdeps/gnu/getutxid.c: New file.
	* sysdeps/gnu/getutxline.c: New file.
	* sysdeps/gnu/pututxline.c: New file.
	* sysdeps/gnu/utmpxname.c: New file.
	* sysdeps/gnu/updwtmpx.c: New file.
	* sysdeps/unix/sysv/linux/paths.h (_PATH_UTMP_DB): Remove.
	* sysdeps/generic/bits/utmpx.h: Remove.

1998-04-20  Ulrich Drepper  <drepper@cygnus.com>

	* posix/wordexp-test.c (main): Initialize ifs element of ts for
	~root test.

1998-04-17 07:53  H.J. Lu  <hjl@gnu.org>

	* sysdeps/unix/sysv/linux/i386/s_pread64.S: Fix a typo.

1998-04-17 11:32  Ulrich Drepper  <drepper@cygnus.com>

	* libio/oldfileops.c (_IO_old_file_seekoff): Define temporary st
	variable using _G_stat64.
	* libio/fileops.c: Remove macro definition of fstat, it is in the
	global header.
	Reported by Thorsten Kukuk <kukuk@weber.uni-paderborn.de>.

1998-04-17  Philip Blundell  <pb@nexus.co.uk>

	* sysdeps/arm/strlen.S: New file, based on code by Matthew Wilcox
	<willy@odie.barnet.ac.uk>.

1998-04-16  Philip Blundell  <Philip.Blundell@pobox.com>

	* inet/netinet/in.h (IN6_IS_ADDR_MC_NODELOCAL): New macro,
	required by IPv6 Basic API.
	(IN6_IS_ADDR_MC_LINKLOCAL): Likewise.
	(IN6_IS_ADDR_MC_SITELOCAL): Likewise.
	(IN6_IS_ADDR_MC_ORGLOCAL): Likewise.
	(IN6_IS_ADDR_MC_GLOBAL): Likewise.
Diffstat (limited to 'sysdeps/generic/utmp_file.c')
-rw-r--r--sysdeps/generic/utmp_file.c472
1 files changed, 472 insertions, 0 deletions
diff --git a/sysdeps/generic/utmp_file.c b/sysdeps/generic/utmp_file.c
new file mode 100644
index 0000000000..08675185ce
--- /dev/null
+++ b/sysdeps/generic/utmp_file.c
@@ -0,0 +1,472 @@
+/* Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>
+   and Paul Janzen <pcj@primenet.com>, 1996.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <utmp.h>
+
+#include "utmp-private.h"
+
+
+/* Descriptor for the file and position.  */
+static int file_fd = -1;
+static off_t file_offset;
+
+/* Cache for the last read entry.  */
+static struct utmp last_entry;
+
+
+/* Functions defined here.  */
+static int setutent_file (void);
+static int getutent_r_file (struct utmp *buffer, struct utmp **result);
+static int getutid_r_file (const struct utmp *key, struct utmp *buffer,
+			   struct utmp **result);
+static int getutline_r_file (const struct utmp *key, struct utmp *buffer,
+			     struct utmp **result);
+static struct utmp *pututline_file (const struct utmp *data);
+static void endutent_file (void);
+static int updwtmp_file (const char *file, const struct utmp *utmp);
+
+/* Jump table for file functions.  */
+struct utfuncs __libc_utmp_file_functions =
+{
+  setutent_file,
+  getutent_r_file,
+  getutid_r_file,
+  getutline_r_file,
+  pututline_file,
+  endutent_file,
+  updwtmp_file
+};
+
+
+#ifndef TRANSFORM_UTMP_FILE_NAME
+# define TRANSFORM_UTMP_FILE_NAME(file_name) (file_name)
+#endif
+
+static int
+setutent_file (void)
+{
+  if (file_fd < 0)
+    {
+      const char *file_name;
+
+      file_name = TRANSFORM_UTMP_FILE_NAME (__libc_utmp_file_name);
+
+      file_fd = open (file_name, O_RDWR);
+      if (file_fd == -1)
+	{
+	  /* Hhm, read-write access did not work.  Try read-only.  */
+	  file_fd = open (file_name, O_RDONLY);
+	  if (file_fd == -1)
+	    return 0;
+	}
+    }
+
+  lseek (file_fd, 0, SEEK_SET);
+  file_offset = 0;
+
+#if _HAVE_UT_TYPE - 0
+  /* Make sure the entry won't match.  */
+  last_entry.ut_type = -1;
+#endif
+
+  return 1;
+}
+
+
+static int
+getutent_r_file (struct utmp *buffer, struct utmp **result)
+{
+  ssize_t nbytes;
+  struct flock fl;			/* Information struct for locking.  */
+
+  assert (file_fd >= 0);
+
+  if (file_offset == -1l)
+    {
+      /* Not available.  */
+      *result = NULL;
+      return -1;
+    }
+
+  /* XXX The following is not perfect.  Instead of locking the file itself
+     Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl> suggests to
+     use an extra locking file.  */
+  /* XXX I think using an extra locking file does not solve the
+     problems.  Instead we should set an alarm, which causes fcntl to
+     fail, as in ../nis/lckcache.c.
+     Mark Kettenis <kettenis@phys.uva.nl>.  */
+
+  /* Try to get the lock.  */
+  memset (&fl, '\0', sizeof (struct flock));
+  fl.l_type = F_RDLCK;
+  fl.l_whence = SEEK_SET;
+  fcntl (file_fd, F_SETLK, &fl);
+
+  /* Read the next entry.  */
+  nbytes = read (file_fd, &last_entry, sizeof (struct utmp));
+
+  /* And unlock the file.  */
+  fl.l_type = F_UNLCK;
+  fcntl (file_fd, F_SETLKW, &fl);
+
+  if (nbytes != sizeof (struct utmp))
+    {
+      file_offset = -1l;
+      *result = NULL;
+      return -1;
+    }
+
+  /* Update position pointer.  */
+  file_offset += sizeof (struct utmp);
+
+  memcpy (buffer, &last_entry, sizeof (struct utmp));
+  *result = buffer;
+
+  return 0;
+}
+
+
+static int
+proc_utmp_eq (const struct utmp *entry, const struct utmp *match)
+{
+  return
+    (
+#if _HAVE_UT_TYPE - 0
+     (entry->ut_type == INIT_PROCESS
+      || entry->ut_type == LOGIN_PROCESS
+      || entry->ut_type == USER_PROCESS
+      || entry->ut_type == DEAD_PROCESS)
+     &&
+     (match->ut_type == INIT_PROCESS
+      || match->ut_type == LOGIN_PROCESS
+      || match->ut_type == USER_PROCESS
+      || match->ut_type == DEAD_PROCESS)
+     &&
+#endif
+#if _HAVE_UT_ID - 0
+     (entry->ut_id[0] && match->ut_id[0]
+      ? strncmp (entry->ut_id, match->ut_id, sizeof match->ut_id) == 0
+      : strncmp (entry->ut_line, match->ut_line, sizeof match->ut_line) == 0)
+#else
+     strncmp (entry->ut_line, match->ut_line, sizeof match->ut_line) == 0
+#endif
+     );
+}
+
+static int
+internal_getut_r (const struct utmp *id, struct utmp *buffer)
+{
+  int result = -1;
+  struct flock fl;
+
+  /* Try to get the lock.  */
+  memset (&fl, '\0', sizeof (struct flock));
+  fl.l_type = F_RDLCK;
+  fl.l_whence = SEEK_SET;
+  fcntl (file_fd, F_SETLKW, &fl);
+
+#if _HAVE_UT_TYPE - 0
+  if (id->ut_type == RUN_LVL || id->ut_type == BOOT_TIME
+      || id->ut_type == OLD_TIME || id->ut_type == NEW_TIME)
+    {
+      /* Search for next entry with type RUN_LVL, BOOT_TIME,
+	 OLD_TIME, or NEW_TIME.  */
+
+      while (1)
+	{
+	  /* Read the next entry.  */
+	  if (read (file_fd, buffer, sizeof (struct utmp))
+	      != sizeof (struct utmp))
+	    {
+	      __set_errno (ESRCH);
+	      file_offset = -1l;
+	      goto unlock_return;
+	    }
+	  file_offset += sizeof (struct utmp);
+
+	  if (id->ut_type == buffer->ut_type)
+	    break;
+	}
+    }
+  else
+#endif /* _HAVE_UT_TYPE */
+    {
+      /* Search for the next entry with the specified ID and with type
+	 INIT_PROCESS, LOGIN_PROCESS, USER_PROCESS, or DEAD_PROCESS.  */
+
+      while (1)
+	{
+	  /* Read the next entry.  */
+	  if (read (file_fd, buffer, sizeof (struct utmp))
+	      != sizeof (struct utmp))
+	    {
+	      __set_errno (ESRCH);
+	      file_offset = -1l;
+	      goto unlock_return;
+	    }
+	  file_offset += sizeof (struct utmp);
+
+	  if (proc_utmp_eq (buffer, id))
+	    break;
+	}
+    }
+
+  result = 0;
+
+unlock_return:
+  /* And unlock the file.  */
+  fl.l_type = F_UNLCK;
+  fcntl (file_fd, F_SETLK, &fl);
+
+  return result;
+}
+
+
+/* For implementing this function we don't use the getutent_r function
+   because we can avoid the reposition on every new entry this way.  */
+static int
+getutid_r_file (const struct utmp *id, struct utmp *buffer,
+		struct utmp **result)
+{
+  assert (file_fd >= 0);
+
+  if (file_offset == -1l)
+    {
+      *result = NULL;
+      return -1;
+    }
+
+  if (internal_getut_r (id, &last_entry) < 0)
+    {
+      *result = NULL;
+      return -1;
+    }
+
+  memcpy (buffer, &last_entry, sizeof (struct utmp));
+  *result = buffer;
+
+  return 0;
+}
+
+
+/* For implementing this function we don't use the getutent_r function
+   because we can avoid the reposition on every new entry this way.  */
+static int
+getutline_r_file (const struct utmp *line, struct utmp *buffer,
+		  struct utmp **result)
+{
+  struct flock fl;
+
+  assert (file_fd >= 0);
+
+  if (file_offset == -1l)
+    {
+      *result = NULL;
+      return -1;
+    }
+
+  /* Try to get the lock.  */
+  memset (&fl, '\0', sizeof (struct flock));
+  fl.l_type = F_RDLCK;
+  fl.l_whence = SEEK_SET;
+  fcntl (file_fd, F_SETLKW, &fl);
+
+  while (1)
+    {
+      /* Read the next entry.  */
+      if (read (file_fd, &last_entry, sizeof (struct utmp))
+	  != sizeof (struct utmp))
+	{
+	  __set_errno (ESRCH);
+	  file_offset = -1l;
+	  *result = NULL;
+	  goto unlock_return;
+	}
+      file_offset += sizeof (struct utmp);
+
+      /* Stop if we found a user or login entry.  */
+      if (
+#if _HAVE_UT_TYPE - 0
+	  (last_entry.ut_type == USER_PROCESS
+	   || last_entry.ut_type == LOGIN_PROCESS)
+	  &&
+#endif
+	  !strncmp (line->ut_line, last_entry.ut_line, sizeof line->ut_line))
+	break;
+    }
+
+  memcpy (buffer, &last_entry, sizeof (struct utmp));
+  *result = buffer;
+
+unlock_return:
+  /* And unlock the file.  */
+  fl.l_type = F_UNLCK;
+  fcntl (file_fd, F_SETLK, &fl);
+
+  return ((*result == NULL) ? -1 : 0);
+}
+
+
+static struct utmp *
+pututline_file (const struct utmp *data)
+{
+  struct flock fl;			/* Information struct for locking.  */
+  struct utmp buffer;
+  struct utmp *pbuf;
+  int found;
+
+  assert (file_fd >= 0);
+
+  /* Find the correct place to insert the data.  */
+  if (file_offset > 0
+      && (
+#if _HAVE_UT_TYPE - 0
+	  (last_entry.ut_type == data->ut_type
+	   && (last_entry.ut_type == RUN_LVL
+	       || last_entry.ut_type == BOOT_TIME
+	       || last_entry.ut_type == OLD_TIME
+	       || last_entry.ut_type == NEW_TIME))
+	  ||
+#endif
+	  proc_utmp_eq (&last_entry, data)))
+    found = 1;
+  else
+    found = internal_getut_r (data, &buffer);
+
+  /* Try to lock the file.  */
+  memset (&fl, '\0', sizeof (struct flock));
+  fl.l_type = F_WRLCK;
+  fl.l_whence = SEEK_SET;
+  fcntl (file_fd, F_SETLK, &fl);
+
+  if (found < 0)
+    {
+      /* We append the next entry.  */
+      file_offset = lseek (file_fd, 0, SEEK_END);
+      if (file_offset % sizeof (struct utmp) != 0)
+	{
+	  file_offset -= file_offset % sizeof (struct utmp);
+	  __ftruncate (file_fd, file_offset);
+
+	  if (lseek (file_fd, 0, SEEK_END) < 0)
+	    {
+	      pbuf = NULL;
+	      goto unlock_return;
+	    }
+	}
+    }
+  else
+    {
+      /* We replace the just read entry.  */
+      file_offset -= sizeof (struct utmp);
+      lseek (file_fd, file_offset, SEEK_SET);
+    }
+
+  /* Write the new data.  */
+  if (write (file_fd, data, sizeof (struct utmp)) != sizeof (struct utmp))
+    {
+      /* If we appended a new record this is only partially written.
+	 Remove it.  */
+      if (found < 0)
+	(void) __ftruncate (file_fd, file_offset);
+      pbuf = NULL;
+    }
+  else
+    {
+      file_offset += sizeof (struct utmp);
+      pbuf = (struct utmp *) data;
+    }
+
+ unlock_return:
+   /* And unlock the file.  */
+  fl.l_type = F_UNLCK;
+  fcntl (file_fd, F_SETLK, &fl);
+
+  return pbuf;
+}
+
+
+static void
+endutent_file (void)
+{
+  assert (file_fd >= 0);
+
+  close (file_fd);
+  file_fd = -1;
+}
+
+
+static int
+updwtmp_file (const char *file, const struct utmp *utmp)
+{
+  int result = -1;
+  struct flock fl;
+  off_t offset;
+  int fd;
+
+  /* Open WTMP file.  */
+  fd = open (file, O_WRONLY);
+  if (fd < 0)
+    return -1;
+
+  /* Try to get the lock.  */
+  memset (&fl, '\0', sizeof (struct flock));
+  fl.l_type = F_WRLCK;
+  fl.l_whence = SEEK_SET;
+  fcntl (fd, F_SETLK, &fl);
+
+  /* Remember original size of log file.  */
+  offset = lseek (fd, 0, SEEK_END);
+  if (offset % sizeof (struct utmp) != 0)
+    {
+      offset -= offset % sizeof (struct utmp);
+      __ftruncate (fd, offset);
+
+      if (lseek (fd, 0, SEEK_END) < 0)
+	goto unlock_return;
+    }
+
+  /* Write the entry.  If we can't write all the bytes, reset the file
+     size back to the original size.  That way, no partial entries
+     will remain.  */
+  if (write (fd, utmp, sizeof (struct utmp)) != sizeof (struct utmp))
+    {
+      __ftruncate (fd, offset);
+      goto unlock_return;
+    }
+
+  result = 0;
+
+unlock_return:
+  /* And unlock the file.  */
+  fl.l_type = F_UNLCK;
+  fcntl (fd, F_SETLKW, &fl);
+
+  /* Close WTMP file.  */
+  close (fd);
+
+  return result;
+}