[BZ #9955]

2009-04-23  Ulrich Drepper  <drepper@redhat.com>
	[BZ #9955]
	* gshadow/Makefile: New file.
	* gshadow/Versions: New file.
	* gshadow/fgetsgent.c: New file.
	* gshadow/fgetsgent_r.c: New file.
	* gshadow/getsgent.c: New file.
	* gshadow/getsgent_r.c: New file.
	* gshadow/getsgnam.c: New file.
	* gshadow/getsgnam_r.c: New file.
	* gshadow/gshadow.h: New file.
	* gshadow/putsgent.c: New file.
	* gshadow/sgetsgent.c: New file.
	* gshadow/sgetsgent_r.c: New file.
	* gshadow/tst-gshadow.c: New file.
	* include/gshadow.h: New file.
	* Makeconfig (all-subdirs): Add gshadow.
	* Makefile (installed-headers): Add gshadow/gshadow.h.
	* nss/Makefile (databases): Add sgrp.
	* nss/Versions: Add gshadow functions as private exports.
	* nss/nsswitch.conf: Add gshadow entry.
	* nss/sgrp-lookup.c: New file.
	* nss/nss_files/files-parse.c: Add STRING_LIST macro.  Rewrite
	parse_list to handle STRING_LIST and TRAILING_LIST_PARSER.
	* nss/nss_files/files-sgrp.c: New file.
	* sysdeps/generic/paths.h: Add _PATH_GSHADOW.
	* sysdeps/unix/sysv/linux/paths.h: Likewise.

13 files changed, 831 insertions, 0 deletions

diff --git a/gshadow/Makefile b/gshadow/Makefile
new file mode 100644
index 0000000..0c3d42b
--- /dev/null
+++ b/gshadow/Makefile
@@ -0,0 +1,38 @@
+# Copyright (C) 2009 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
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 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
+# Lesser General Public License for more details.
+
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, write to the Free
+# Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+# 02111-1307 USA.
+
+#
+#	Makefile for gshadow.
+#
+subdir	:= gshadow
+
+headers		= gshadow.h
+routines	= getsgent getsgnam sgetsgent fgetsgent putsgent \
+		  getsgent_r getsgnam_r sgetsgent_r fgetsgent_r
+
+tests = tst-gshadow
+
+CFLAGS-getsgent_r.c = -fexceptions
+CFLAGS-getsgent.c = -fexceptions
+CFLAGS-fgetsgent.c = -fexceptions
+CFLAGS-fgetsgent_r.c = -fexceptions -D_IO_MTSAFE_IO
+CFLAGS-putsgent.c = -fexceptions -D_IO_MTSAFE_IO
+CFLAGS-getsgnam.c = -fexceptions
+CFLAGS-getsgnam_r.c = -fexceptions
+
+include ../Rules
diff --git a/gshadow/Versions b/gshadow/Versions
new file mode 100644
index 0000000..00a410b
--- /dev/null
+++ b/gshadow/Versions
@@ -0,0 +1,21 @@
+libc {
+  GLIBC_2.10 {
+    # e*
+    endsgent;
+
+    # f*
+    fgetsgent; fgetsgent_r;
+
+    # g*
+    getsgent; getsgent_r; getsgnam; getsgnam_r; getsgent_r; getsgnam_r;
+
+    # p*
+    putsgent;
+
+    # s*
+    setsgent;
+
+    # s*
+    sgetsgent; sgetsgent_r;
+  }
+}
diff --git a/gshadow/fgetsgent.c b/gshadow/fgetsgent.c
new file mode 100644
index 0000000..098edfe
--- /dev/null
+++ b/gshadow/fgetsgent.c
@@ -0,0 +1,88 @@
+/* Copyright (C) 2009 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <bits/libc-lock.h>
+#include <gshadow.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+
+/* A reasonable size for a buffer to start with.  */
+#define BUFLEN_SPWD 1024
+
+/* We need to protect the dynamic buffer handling.  */
+__libc_lock_define_initialized (static, lock);
+
+libc_freeres_ptr (static char *buffer);
+
+/* Read one shadow entry from the given stream.  */
+struct sgrp *
+fgetsgent (FILE *stream)
+{
+  static size_t buffer_size;
+  static struct sgrp resbuf;
+  fpos_t pos;
+  struct sgrp *result;
+  int save;
+
+  if (fgetpos (stream, &pos) != 0)
+    return NULL;
+
+  /* Get lock.  */
+  __libc_lock_lock (lock);
+
+  /* Allocate buffer if not yet available.  */
+  if (buffer == NULL)
+    {
+      buffer_size = BUFLEN_SPWD;
+      buffer = malloc (buffer_size);
+    }
+
+  while (buffer != NULL
+	 && (__fgetsgent_r (stream, &resbuf, buffer, buffer_size, &result)
+	     == ERANGE))
+    {
+      char *new_buf;
+      buffer_size += BUFLEN_SPWD;
+      new_buf = realloc (buffer, buffer_size);
+      if (new_buf == NULL)
+	{
+	  /* We are out of memory.  Free the current buffer so that the
+	     process gets a chance for a normal termination.  */
+	  save = errno;
+	  free (buffer);
+	  __set_errno (save);
+	}
+      buffer = new_buf;
+
+      /* Reset the stream.  */
+      if (fsetpos (stream, &pos) != 0)
+	buffer = NULL;
+    }
+
+  if (buffer == NULL)
+    result = NULL;
+
+  /* Release lock.  Preserve error value.  */
+  save = errno;
+  __libc_lock_unlock (lock);
+  __set_errno (save);
+
+  return result;
+}
diff --git a/gshadow/fgetsgent_r.c b/gshadow/fgetsgent_r.c
new file mode 100644
index 0000000..25c05bf7
--- /dev/null
+++ b/gshadow/fgetsgent_r.c
@@ -0,0 +1,76 @@
+/* Copyright (C) 2009 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <ctype.h>
+#include <errno.h>
+#include <gshadow.h>
+#include <stdio.h>
+
+/* Define a line parsing function using the common code
+   used in the nss_files module.  */
+
+#define STRUCTURE	sgrp
+#define ENTNAME		sgent
+#define	EXTERN_PARSER	1
+struct sgent_data {};
+
+#include <nss/nss_files/files-parse.c>
+
+
+/* Read one shadow entry from the given stream.  */
+int
+__fgetsgent_r (FILE *stream, struct sgrp *resbuf, char *buffer, size_t buflen,
+	       struct sgrp **result)
+{
+  char *p;
+
+  _IO_flockfile (stream);
+  do
+    {
+      buffer[buflen - 1] = '\xff';
+      p = fgets_unlocked (buffer, buflen, stream);
+      if (p == NULL && feof_unlocked (stream))
+	{
+	  _IO_funlockfile (stream);
+	  *result = NULL;
+	  __set_errno (ENOENT);
+	  return errno;
+	}
+      if (p == NULL || buffer[buflen - 1] != '\xff')
+	{
+	  _IO_funlockfile (stream);
+	  *result = NULL;
+	  __set_errno (ERANGE);
+	  return errno;
+	}
+
+      /* Skip leading blanks.  */
+      while (isspace (*p))
+	++p;
+    } while (*p == '\0' || *p == '#' ||	/* Ignore empty and comment lines.  */
+	     /* Parse the line.  If it is invalid, loop to
+		get the next line of the file to parse.  */
+	     ! parse_line (buffer, (void *) resbuf, (void *) buffer, buflen,
+			   &errno));
+
+  _IO_funlockfile (stream);
+
+  *result = resbuf;
+  return 0;
+}
+weak_alias (__fgetsgent_r, fgetsgent_r)
diff --git a/gshadow/getsgent.c b/gshadow/getsgent.c
new file mode 100644
index 0000000..544227c
--- /dev/null
+++ b/gshadow/getsgent.c
@@ -0,0 +1,30 @@
+/* Copyright (C) 2009 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2009.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <gshadow.h>
+
+
+#define LOOKUP_TYPE	struct sgrp
+#define SETFUNC_NAME	setsgent
+#define	GETFUNC_NAME	getsgent
+#define	ENDFUNC_NAME	endsgent
+#define DATABASE_NAME	gshadow
+#define BUFLEN		1024
+
+#include "../nss/getXXent.c"
diff --git a/gshadow/getsgent_r.c b/gshadow/getsgent_r.c
new file mode 100644
index 0000000..336110e
--- /dev/null
+++ b/gshadow/getsgent_r.c
@@ -0,0 +1,30 @@
+/* Copyright (C) 2009 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2009.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <gshadow.h>
+
+
+#define LOOKUP_TYPE		struct sgrp
+#define SETFUNC_NAME		setsgent
+#define	GETFUNC_NAME		getsgent
+#define	ENDFUNC_NAME		endsgent
+#define DATABASE_NAME		gshadow
+#define BUFLEN			1024
+
+#include "../nss/getXXent_r.c"
diff --git a/gshadow/getsgnam.c b/gshadow/getsgnam.c
new file mode 100644
index 0000000..7cd5b44
--- /dev/null
+++ b/gshadow/getsgnam.c
@@ -0,0 +1,30 @@
+/* Copyright (C) 2009 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2009.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <gshadow.h>
+
+
+#define LOOKUP_TYPE	struct sgrp
+#define FUNCTION_NAME	getsgnam
+#define DATABASE_NAME	gshadow
+#define ADD_PARAMS	const char *name
+#define ADD_VARIABLES	name
+#define BUFLEN		1024
+
+#include "../nss/getXXbyYY.c"
diff --git a/gshadow/getsgnam_r.c b/gshadow/getsgnam_r.c
new file mode 100644
index 0000000..c89fb06
--- /dev/null
+++ b/gshadow/getsgnam_r.c
@@ -0,0 +1,30 @@
+/* Copyright (C) 2009 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2009.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <gshadow.h>
+
+
+#define LOOKUP_TYPE		struct sgrp
+#define FUNCTION_NAME		getsgnam
+#define DATABASE_NAME		gshadow
+#define ADD_PARAMS		const char *name
+#define ADD_VARIABLES		name
+#define BUFLEN			1024
+
+#include "../nss/getXXbyYY_r.c"
diff --git a/gshadow/gshadow.h b/gshadow/gshadow.h
new file mode 100644
index 0000000..d0b28ae
--- /dev/null
+++ b/gshadow/gshadow.h
@@ -0,0 +1,131 @@
+/* Copyright (C) 2009 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+/* Declaration of types and functions for shadow group suite.  */
+
+#ifndef _GSHADOW_H
+#define _GSHADOW_H	1
+
+#include <features.h>
+
+#include <paths.h>
+
+#define	__need_FILE
+#include <stdio.h>
+#define __need_size_t
+#include <stddef.h>
+
+/* Path to the user database files.  */
+#define	GSHADOW _PATH_GSHADOW
+
+
+__BEGIN_DECLS
+
+/* Structure of the group file.  */
+struct sgrp
+  {
+    char *sg_namp;		/* Group name.  */
+    char *sg_passwd;		/* Encrypted password.  */
+    char **sg_adm;		/* Group administrator list.  */
+    char **sg_mem;		/* Group member list.  */
+  };
+
+
+/* Open database for reading.
+
+   This function is not part of POSIX and therefore no official
+   cancellation point.  But due to similarity with an POSIX interface
+   or due to the implementation it is a cancellation point and
+   therefore not marked with __THROW.  */
+extern void setsgent (void);
+
+/* Close database.
+
+   This function is not part of POSIX and therefore no official
+   cancellation point.  But due to similarity with an POSIX interface
+   or due to the implementation it is a cancellation point and
+   therefore not marked with __THROW.  */
+extern void endsgent (void);
+
+/* Get next entry from database, perhaps after opening the file.
+
+   This function is not part of POSIX and therefore no official
+   cancellation point.  But due to similarity with an POSIX interface
+   or due to the implementation it is a cancellation point and
+   therefore not marked with __THROW.  */
+extern struct sgrp *getsgent (void);
+
+/* Get shadow entry matching NAME.
+
+   This function is not part of POSIX and therefore no official
+   cancellation point.  But due to similarity with an POSIX interface
+   or due to the implementation it is a cancellation point and
+   therefore not marked with __THROW.  */
+extern struct sgrp *getsgnam (__const char *__name);
+
+/* Read shadow entry from STRING.
+
+   This function is not part of POSIX and therefore no official
+   cancellation point.  But due to similarity with an POSIX interface
+   or due to the implementation it is a cancellation point and
+   therefore not marked with __THROW.  */
+extern struct sgrp *sgetsgent (__const char *__string);
+
+/* Read next shadow entry from STREAM.
+
+   This function is not part of POSIX and therefore no official
+   cancellation point.  But due to similarity with an POSIX interface
+   or due to the implementation it is a cancellation point and
+   therefore not marked with __THROW.  */
+extern struct sgrp *fgetsgent (FILE *__stream);
+
+/* Write line containing shadow password entry to stream.
+
+   This function is not part of POSIX and therefore no official
+   cancellation point.  But due to similarity with an POSIX interface
+   or due to the implementation it is a cancellation point and
+   therefore not marked with __THROW.  */
+extern int putsgent (__const struct sgrp *__g, FILE *__stream);
+
+
+#ifdef __USE_MISC
+/* Reentrant versions of some of the functions above.
+
+   These functions are not part of POSIX and therefore no official
+   cancellation point.  But due to similarity with an POSIX interface
+   or due to the implementation they are cancellation points and
+   therefore not marked with __THROW.  */
+extern int getsgent_r (struct sgrp *__result_buf, char *__buffer,
+		       size_t __buflen, struct sgrp **__result);
+
+extern int getsgnam_r (__const char *__name, struct sgrp *__result_buf,
+		       char *__buffer, size_t __buflen,
+		       struct sgrp **__result);
+
+extern int sgetsgent_r (__const char *__string, struct sgrp *__result_buf,
+			char *__buffer, size_t __buflen,
+			struct sgrp **__result);
+
+extern int fgetsgent_r (FILE *__stream, struct sgrp *__result_buf,
+			char *__buffer, size_t __buflen,
+			struct sgrp **__result);
+#endif	/* misc */
+
+__END_DECLS
+
+#endif /* gshadow.h */
diff --git a/gshadow/putsgent.c b/gshadow/putsgent.c
new file mode 100644
index 0000000..938a713
--- /dev/null
+++ b/gshadow/putsgent.c
@@ -0,0 +1,71 @@
+/* Copyright (C) 2009 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <gshadow.h>
+
+#define _S(x)	x ? x : ""
+
+
+/* Write an entry to the given stream.
+   This must know the format of the group file.  */
+int
+putsgent (const struct sgrp *g, FILE *stream)
+{
+  int errors = 0;
+
+  _IO_flockfile (stream);
+
+  if (fprintf (stream, "%s:%s:", g->sg_namp, _S (g->sg_passwd)) < 0)
+    ++errors;
+
+  bool first = true;
+  char **sp = g->sg_adm;
+  if (sp != NULL)
+    while (*sp != NULL)
+      {
+	if (fprintf (stream, "%s%s", first ? "" : ",", *sp++) < 0)
+	  {
+	    ++errors;
+	    break;
+	  }
+	first = false;
+      }
+  if (putc_unlocked (':', stream) == EOF)
+    ++errors;
+
+  first = true;
+  sp = g->sg_mem;
+  if (sp != NULL)
+    while (*sp != NULL)
+      {
+	if (fprintf (stream, "%s%s", first ? "" : ",", *sp++) < 0)
+	  {
+	    ++errors;
+	    break;
+	  }
+	first = false;
+      }
+  if (putc_unlocked ('\n', stream) == EOF)
+    ++errors;
+
+  _IO_funlockfile (stream);
+
+  return errors ? -1 : 0;
+}
diff --git a/gshadow/sgetsgent.c b/gshadow/sgetsgent.c
new file mode 100644
index 0000000..94e1315
--- /dev/null
+++ b/gshadow/sgetsgent.c
@@ -0,0 +1,78 @@
+/* Copyright (C) 2009 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <bits/libc-lock.h>
+#include <gshadow.h>
+#include <stdlib.h>
+
+
+/* A reasonable size for a buffer to start with.  */
+#define BUFLEN_SPWD 1024
+
+/* We need to protect the dynamic buffer handling.  */
+__libc_lock_define_initialized (static, lock);
+
+/* Read one shadow entry from the given stream.  */
+struct sgrp *
+sgetsgent (const char *string)
+{
+  static char *buffer;
+  static size_t buffer_size;
+  static struct sgrp resbuf;
+  struct sgrp *result;
+  int save;
+
+  /* Get lock.  */
+  __libc_lock_lock (lock);
+
+  /* Allocate buffer if not yet available.  */
+  if (buffer == NULL)
+    {
+      buffer_size = BUFLEN_SPWD;
+      buffer = malloc (buffer_size);
+    }
+
+  while (buffer != NULL
+	 && __sgetsgent_r (string, &resbuf, buffer, buffer_size, &result) != 0
+	 && errno == ERANGE)
+    {
+      char *new_buf;
+      buffer_size += BUFLEN_SPWD;
+      new_buf = realloc (buffer, buffer_size);
+      if (new_buf == NULL)
+	{
+	  /* We are out of memory.  Free the current buffer so that the
+	     process gets a chance for a normal termination.  */
+	  save = errno;
+	  free (buffer);
+	  __set_errno (save);
+	}
+      buffer = new_buf;
+    }
+
+  if (buffer == NULL)
+    result = NULL;
+
+  /* Release lock.  Preserve error value.  */
+  save = errno;
+  __libc_lock_unlock (lock);
+  __set_errno (save);
+
+  return result;
+}
diff --git a/gshadow/sgetsgent_r.c b/gshadow/sgetsgent_r.c
new file mode 100644
index 0000000..72c51fe
--- /dev/null
+++ b/gshadow/sgetsgent_r.c
@@ -0,0 +1,70 @@
+/* Copyright (C) 2009 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <ctype.h>
+#include <errno.h>
+#include <gshadow.h>
+#include <stdio.h>
+#include <string.h>
+
+/* Define a line parsing function using the common code
+   used in the nss_files module.  */
+
+#define STRUCTURE	sgrp
+#define ENTNAME		sgent
+struct sgent_data {};
+
+
+#define TRAILING_LIST_MEMBER		sg_mem
+#define TRAILING_LIST_SEPARATOR_P(c)	((c) == ',')
+#include <nss/nss_files/files-parse.c>
+LINE_PARSER
+(,
+ STRING_FIELD (result->sg_namp, ISCOLON, 0);
+ if (line[0] == '\0'
+     && (result->sg_namp[0] == '+' || result->sg_namp[0] == '-'))
+   {
+     result->sg_passwd = NULL;
+     result->sg_adm = NULL;
+     result->sg_mem = NULL;
+   }
+ else
+   {
+     STRING_FIELD (result->sg_passwd, ISCOLON, 0);
+     STRING_LIST (result->sg_adm, ':');
+   }
+ )
+
+
+/* Read one shadow entry from the given stream.  */
+int
+__sgetsgent_r (const char *string, struct sgrp *resbuf, char *buffer,
+	       size_t buflen, struct sgrp **result)
+{
+  char *sp;
+  if (string < buffer || string >= buffer + buflen)
+    sp = strncpy (buffer, string, buflen);
+  else
+    sp = (char *) string;
+
+  int parse_result = parse_line (sp, resbuf, (void *) buffer, buflen, &errno);
+  *result = parse_result > 0 ? resbuf : NULL;
+
+  return *result == NULL ? errno : 0;
+}
+weak_alias (__sgetsgent_r, sgetsgent_r)
diff --git a/gshadow/tst-gshadow.c b/gshadow/tst-gshadow.c
new file mode 100644
index 0000000..8c26a48
--- /dev/null
+++ b/gshadow/tst-gshadow.c
@@ -0,0 +1,138 @@
+#include <gshadow.h>
+#include <stdio.h>
+#include <string.h>
+
+
+static const struct sgrp data[] =
+  {
+    { (char *) "one", (char *) "pwdone",
+      (char *[]) { (char *) "admoneone", (char *) "admonetwo",
+		  (char *) "admonethree", NULL },
+      (char *[]) { (char *) "memoneone", (char *) "memonetwo",
+		  (char *) "memonethree", NULL } },
+    { (char *) "two", (char *) "pwdtwo",
+      (char *[]) { (char *) "admtwoone", (char *) "admtwotwo", NULL },
+      (char *[]) { (char *) "memtwoone", (char *) "memtwotwo",
+		  (char *) "memtwothree", NULL } },
+    { (char *) "three", (char *) "pwdthree",
+      (char *[]) { (char *) "admthreeone", (char *) "admthreetwo", NULL },
+      (char *[]) { (char *) "memthreeone", (char *) "memthreetwo", NULL } },
+    { (char *) "four", (char *) "pwdfour",
+      (char *[]) { (char *) "admfourone", (char *) "admfourtwo", NULL },
+      (char *[]) { NULL } },
+    { (char *) "five", (char *) "pwdfive",
+      (char *[]) { NULL },
+      (char *[]) { (char *) "memfiveone", (char *) "memfivetwo", NULL } },
+  };
+#define ndata (sizeof (data) / sizeof (data[0]))
+
+
+int
+main (void)
+{
+  FILE *fp = fopen ("/tmp/aaa", "w+");//tmpfile ();
+  if (fp == NULL)
+    {
+      puts ("cannot open temporary file");
+      return 1;
+    }
+
+  for (size_t i = 0; i < ndata; ++i)
+    if (putsgent (&data[i], fp) != 0)
+      {
+	printf ("putsgent call %zu failed\n", i + 1);
+	return 1;
+      }
+
+  rewind (fp);
+
+  int result = 0;
+  int seen = -1;
+  struct sgrp *g;
+  while ((g = fgetsgent (fp)) != NULL)
+    {
+      ++seen;
+      if (strcmp (g->sg_namp, data[seen].sg_namp) != 0)
+	{
+	  printf ("sg_namp of entry %d does not match: %s vs %s\n",
+		  seen + 1, g->sg_namp, data[seen].sg_namp);
+	  result = 1;
+	}
+      if (strcmp (g->sg_passwd, data[seen].sg_passwd) != 0)
+	{
+	  printf ("sg_passwd of entry %d does not match: %s vs %s\n",
+		  seen + 1, g->sg_passwd, data[seen].sg_passwd);
+	  result = 1;
+	}
+      if (g->sg_adm == NULL)
+	{
+	  printf ("sg_adm of entry %d is NULL\n", seen + 1);
+	  result = 1;
+	}
+      else
+	{
+	  int i = 1;
+	  char **sp1 = g->sg_adm;
+	  char **sp2 = data[seen].sg_adm;
+	  while (*sp1 != NULL && *sp2 != NULL)
+	    {
+	      if (strcmp (*sp1, *sp2) != 0)
+		{
+		  printf ("sg_adm[%d] of entry %d does not match: %s vs %s\n",
+			  i, seen + 1, *sp1, *sp2);
+		  result = 1;
+		}
+	      ++sp1;
+	      ++sp2;
+	      ++i;
+	    }
+	  if (*sp1 == NULL && *sp2 != NULL)
+	    {
+	      printf ("sg_adm of entry %d has too few entries\n", seen + 1);
+	      result = 1;
+	    }
+	  else if (*sp1 != NULL && *sp2 == NULL)
+	    {
+	      printf ("sg_adm of entry %d has too many entries\n", seen + 1);
+	      result = 1;
+	    }
+	}
+      if (g->sg_mem == NULL)
+	{
+	  printf ("sg_mem of entry %d is NULL\n", seen + 1);
+	  result = 1;
+	}
+      else
+	{
+	  int i = 1;
+	  char **sp1 = g->sg_mem;
+	  char **sp2 = data[seen].sg_mem;
+	  while (*sp1 != NULL && *sp2 != NULL)
+	    {
+	      if (strcmp (*sp1, *sp2) != 0)
+		{
+		  printf ("sg_mem[%d] of entry %d does not match: %s vs %s\n",
+			  i, seen + 1, *sp1, *sp2);
+		  result = 1;
+		}
+	      ++sp1;
+	      ++sp2;
+	      ++i;
+	    }
+	  if (*sp1 == NULL && *sp2 != NULL)
+	    {
+	      printf ("sg_mem of entry %d has too few entries\n", seen + 1);
+	      result = 1;
+	    }
+	  else if (*sp1 != NULL && *sp2 == NULL)
+	    {
+	      printf ("sg_mem of entry %d has too many entries\n", seen + 1);
+	      result = 1;
+	    }
+	}
+    }
+
+  fclose (fp);
+
+  return result;
+}