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/* Copyright (C) 1996-2019 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, see
<https://www.gnu.org/licenses/>. */
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>
#include <libc-lock.h>
#include <libnsl.h>
/* Path of the file. */
static const char default_nss[] = "/etc/default/nss";
/* Flags once read from the file. */
static int default_nss_flags;
/* Code to make sure we call 'init' once. */
__libc_once_define (static, once);
/* Table of the recognized variables. */
static const struct
{
char name[23];
unsigned int len;
int flag;
} vars[] =
{
#define STRNLEN(s) s, sizeof (s) - 1
{ STRNLEN ("NETID_AUTHORITATIVE"), NSS_FLAG_NETID_AUTHORITATIVE },
{ STRNLEN ("SERVICES_AUTHORITATIVE"), NSS_FLAG_SERVICES_AUTHORITATIVE },
{ STRNLEN ("SETENT_BATCH_READ"), NSS_FLAG_SETENT_BATCH_READ },
{ STRNLEN ("ADJUNCT_AS_SHADOW"), NSS_FLAG_ADJUNCT_AS_SHADOW },
};
#define nvars (sizeof (vars) / sizeof (vars[0]))
static void
init (void)
{
int saved_errno = errno;
FILE *fp = fopen (default_nss, "rce");
if (fp != NULL)
{
char *line = NULL;
size_t linelen = 0;
__fsetlocking (fp, FSETLOCKING_BYCALLER);
while (!feof_unlocked (fp))
{
ssize_t n = getline (&line, &linelen, fp);
if (n <= 0)
break;
/* Recognize only
<THE-VARIABLE> = TRUE
with arbitrary white spaces. */
char *cp = line;
while (isspace (*cp))
++cp;
/* Recognize comment lines. */
if (*cp == '#')
continue;
int idx;
for (idx = 0; idx < nvars; ++idx)
if (strncmp (cp, vars[idx].name, vars[idx].len) == 0)
break;
if (idx == nvars)
continue;
cp += vars[idx].len;
while (isspace (*cp))
++cp;
if (*cp++ != '=')
continue;
while (isspace (*cp))
++cp;
if (strncmp (cp, "TRUE", 4) != 0)
continue;
cp += 4;
while (isspace (*cp))
++cp;
if (*cp == '\0')
default_nss_flags |= vars[idx].flag;
}
free (line);
fclose (fp);
}
__set_errno (saved_errno);
}
int
_nsl_default_nss (void)
{
/* If we have not yet read the file yet do it now. */
__libc_once (once, init);
return default_nss_flags;
}
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