summaryrefslogtreecommitdiff
path: root/nss/nss_files/files-netgrp.c
blob: 9cc678b38e569986648e01570e17fa43b65fc9d2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
/* Netgroup file parser in nss_files modules.
   Copyright (C) 1996-2013 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 (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_UNAVAIL;
    }
  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;
}