glibc/nss/nss_files/files-netgrp.c

295 lines
7.3 KiB
C

/* Netgroup file parser in nss_files modules.
Copyright (C) 1996-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
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
<http://www.gnu.org/licenses/>. */
#include <ctype.h>
#include <errno.h>
#include <netdb.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>
#include "nsswitch.h"
#include "netgroup.h"
#define DATAFILE "/etc/netgroup"
libnss_files_hidden_proto (_nss_files_endnetgrent)
#define EXPAND(needed) \
do \
{ \
size_t old_cursor = result->cursor - result->data; \
void *old_data = result->data; \
\
result->data_size += 512 > 2 * needed ? 512 : 2 * needed; \
result->data = realloc (result->data, result->data_size); \
\
if (result->data == NULL) \
{ \
free (old_data); \
status = NSS_STATUS_UNAVAIL; \
goto the_end; \
} \
\
result->cursor = result->data + old_cursor; \
} \
while (0)
enum nss_status
_nss_files_setnetgrent (const char *group, struct __netgrent *result)
{
FILE *fp;
enum nss_status status;
if (group[0] == '\0')
return NSS_STATUS_UNAVAIL;
/* Find the netgroups file and open it. */
fp = fopen (DATAFILE, "rce");
if (fp == NULL)
status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
else
{
/* Read the file line by line and try to find the description
GROUP. We must take care for long lines. */
char *line = NULL;
size_t line_len = 0;
const ssize_t group_len = strlen (group);
status = NSS_STATUS_NOTFOUND;
result->cursor = result->data;
__fsetlocking (fp, FSETLOCKING_BYCALLER);
while (!feof_unlocked (fp))
{
ssize_t curlen = getline (&line, &line_len, fp);
int found;
if (curlen < 0)
{
status = NSS_STATUS_NOTFOUND;
break;
}
found = (curlen > group_len && strncmp (line, group, group_len) == 0
&& isspace (line[group_len]));
/* Read the whole line (including continuation) and store it
if FOUND in nonzero. Otherwise we don't need it. */
if (found)
{
/* Store the data from the first line. */
EXPAND (curlen - group_len);
memcpy (result->cursor, &line[group_len + 1],
curlen - group_len);
result->cursor += (curlen - group_len) - 1;
}
while (curlen > 1 && line[curlen - 1] == '\n'
&& line[curlen - 2] == '\\')
{
/* Yes, we have a continuation line. */
if (found)
/* Remove these characters from the stored line. */
result->cursor -= 2;
/* Get next line. */
curlen = getline (&line, &line_len, fp);
if (curlen <= 0)
break;
if (found)
{
/* Make sure we have enough room. */
EXPAND (1 + curlen + 1);
/* Add separator in case next line starts immediately. */
*result->cursor++ = ' ';
/* Copy new line. */
memcpy (result->cursor, line, curlen + 1);
result->cursor += curlen;
}
}
if (found)
{
/* Now we have read the line. */
status = NSS_STATUS_SUCCESS;
result->cursor = result->data;
result->first = 1;
break;
}
}
the_end:
/* We don't need the file and the line buffer anymore. */
free (line);
fclose (fp);
if (status != NSS_STATUS_SUCCESS)
_nss_files_endnetgrent (result);
}
return status;
}
enum nss_status
_nss_files_endnetgrent (struct __netgrent *result)
{
/* Free allocated memory for data if some is present. */
free (result->data);
result->data = NULL;
result->data_size = 0;
result->cursor = NULL;
return NSS_STATUS_SUCCESS;
}
libnss_files_hidden_def (_nss_files_endnetgrent)
static char *
strip_whitespace (char *str)
{
char *cp = str;
/* Skip leading spaces. */
while (isspace (*cp))
cp++;
str = cp;
while (*cp != '\0' && ! isspace(*cp))
cp++;
/* Null-terminate, stripping off any trailing spaces. */
*cp = '\0';
return *str == '\0' ? NULL : str;
}
enum nss_status
_nss_netgroup_parseline (char **cursor, struct __netgrent *result,
char *buffer, size_t buflen, int *errnop)
{
enum nss_status status;
const char *host, *user, *domain;
char *cp = *cursor;
/* Some sanity checks. */
if (cp == NULL)
return NSS_STATUS_NOTFOUND;
/* First skip leading spaces. */
while (isspace (*cp))
++cp;
if (*cp != '(')
{
/* We have a list of other netgroups. */
char *name = cp;
while (*cp != '\0' && ! isspace (*cp))
++cp;
if (name != cp)
{
/* It is another netgroup name. */
int last = *cp == '\0';
result->type = group_val;
result->val.group = name;
*cp = '\0';
if (! last)
++cp;
*cursor = cp;
result->first = 0;
return NSS_STATUS_SUCCESS;
}
return result->first ? NSS_STATUS_NOTFOUND : NSS_STATUS_RETURN;
}
/* Match host name. */
host = ++cp;
while (*cp != ',')
if (*cp++ == '\0')
return result->first ? NSS_STATUS_NOTFOUND : NSS_STATUS_RETURN;
/* Match user name. */
user = ++cp;
while (*cp != ',')
if (*cp++ == '\0')
return result->first ? NSS_STATUS_NOTFOUND : NSS_STATUS_RETURN;
/* Match domain name. */
domain = ++cp;
while (*cp != ')')
if (*cp++ == '\0')
return result->first ? NSS_STATUS_NOTFOUND : NSS_STATUS_RETURN;
++cp;
/* When we got here we have found an entry. Before we can copy it
to the private buffer we have to make sure it is big enough. */
if (cp - host > buflen)
{
*errnop = ERANGE;
status = NSS_STATUS_TRYAGAIN;
}
else
{
memcpy (buffer, host, cp - host);
result->type = triple_val;
buffer[(user - host) - 1] = '\0'; /* Replace ',' with '\0'. */
result->val.triple.host = strip_whitespace (buffer);
buffer[(domain - host) - 1] = '\0'; /* Replace ',' with '\0'. */
result->val.triple.user = strip_whitespace (buffer + (user - host));
buffer[(cp - host) - 1] = '\0'; /* Replace ')' with '\0'. */
result->val.triple.domain = strip_whitespace (buffer + (domain - host));
status = NSS_STATUS_SUCCESS;
/* Remember where we stopped reading. */
*cursor = cp;
result->first = 0;
}
return status;
}
libnss_files_hidden_def (_nss_netgroup_parseline)
enum nss_status
_nss_files_getnetgrent_r (struct __netgrent *result, char *buffer,
size_t buflen, int *errnop)
{
enum nss_status status;
status = _nss_netgroup_parseline (&result->cursor, result, buffer, buflen,
errnop);
return status;
}