85 lines
2.2 KiB
C
85 lines
2.2 KiB
C
/* Copyright (C) 1991-2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <grp.h>
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#include <bits/libc-lock.h>
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#include <stdio.h>
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#include <stdlib.h>
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/* We need to protect the dynamic buffer handling. */
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__libc_lock_define_initialized (static, lock);
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libc_freeres_ptr (static char *buffer);
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/* Read one entry from the given stream. */
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struct group *
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fgetgrent (FILE *stream)
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{
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static size_t buffer_size;
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static struct group resbuf;
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fpos_t pos;
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struct group *result;
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int save;
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if (__builtin_expect (fgetpos (stream, &pos), 0) != 0)
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return NULL;
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/* Get lock. */
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__libc_lock_lock (lock);
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/* Allocate buffer if not yet available. */
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if (buffer == NULL)
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{
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buffer_size = NSS_BUFLEN_GROUP;
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buffer = malloc (buffer_size);
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}
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while (buffer != NULL
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&& (__fgetgrent_r (stream, &resbuf, buffer, buffer_size, &result)
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== ERANGE))
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{
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char *new_buf;
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buffer_size += NSS_BUFLEN_GROUP;
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new_buf = realloc (buffer, buffer_size);
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if (__glibc_unlikely (new_buf == NULL))
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{
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/* We are out of memory. Free the current buffer so that the
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process gets a chance for a normal termination. */
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save = errno;
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free (buffer);
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__set_errno (save);
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}
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buffer = new_buf;
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/* Reset the stream. */
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if (fsetpos (stream, &pos) != 0)
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buffer = NULL;
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}
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if (buffer == NULL)
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result = NULL;
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/* Release lock. Preserve error value. */
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save = errno;
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__libc_lock_unlock (lock);
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__set_errno (save);
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return result;
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}
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