1/* Netgroup file parser in nss_files modules.
2 Copyright (C) 1996-2017 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
19
20#include <ctype.h>
21#include <errno.h>
22#include <netdb.h>
23#include <stdio.h>
24#include <stdio_ext.h>
25#include <stdlib.h>
26#include <string.h>
27#include "nsswitch.h"
28#include "netgroup.h"
29
30#define DATAFILE "/etc/netgroup"
31
32libnss_files_hidden_proto (_nss_files_endnetgrent)
33
34#define EXPAND(needed) \
35 do \
36 { \
37 size_t old_cursor = result->cursor - result->data; \
38 void *old_data = result->data; \
39 \
40 result->data_size += 512 > 2 * needed ? 512 : 2 * needed; \
41 result->data = realloc (result->data, result->data_size); \
42 \
43 if (result->data == NULL) \
44 { \
45 free (old_data); \
46 status = NSS_STATUS_UNAVAIL; \
47 goto the_end; \
48 } \
49 \
50 result->cursor = result->data + old_cursor; \
51 } \
52 while (0)
53
54
55enum nss_status
56_nss_files_setnetgrent (const char *group, struct __netgrent *result)
57{
58 FILE *fp;
59 enum nss_status status;
60
61 if (group[0] == '\0')
62 return NSS_STATUS_UNAVAIL;
63
64 /* Find the netgroups file and open it. */
65 fp = fopen (DATAFILE, "rce");
66 if (fp == NULL)
67 status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
68 else
69 {
70 /* Read the file line by line and try to find the description
71 GROUP. We must take care for long lines. */
72 char *line = NULL;
73 size_t line_len = 0;
74 const ssize_t group_len = strlen (group);
75
76 status = NSS_STATUS_NOTFOUND;
77 result->cursor = result->data;
78
79 __fsetlocking (fp, FSETLOCKING_BYCALLER);
80
81 while (!feof_unlocked (fp))
82 {
83 ssize_t curlen = getline (&line, &line_len, fp);
84 int found;
85
86 if (curlen < 0)
87 {
88 status = NSS_STATUS_NOTFOUND;
89 break;
90 }
91
92 found = (curlen > group_len && strncmp (line, group, group_len) == 0
93 && isspace (line[group_len]));
94
95 /* Read the whole line (including continuation) and store it
96 if FOUND in nonzero. Otherwise we don't need it. */
97 if (found)
98 {
99 /* Store the data from the first line. */
100 EXPAND (curlen - group_len);
101 memcpy (result->cursor, &line[group_len + 1],
102 curlen - group_len);
103 result->cursor += (curlen - group_len) - 1;
104 }
105
106 while (curlen > 1 && line[curlen - 1] == '\n'
107 && line[curlen - 2] == '\\')
108 {
109 /* Yes, we have a continuation line. */
110 if (found)
111 /* Remove these characters from the stored line. */
112 result->cursor -= 2;
113
114 /* Get next line. */
115 curlen = getline (&line, &line_len, fp);
116 if (curlen <= 0)
117 break;
118
119 if (found)
120 {
121 /* Make sure we have enough room. */
122 EXPAND (1 + curlen + 1);
123
124 /* Add separator in case next line starts immediately. */
125 *result->cursor++ = ' ';
126
127 /* Copy new line. */
128 memcpy (result->cursor, line, curlen + 1);
129 result->cursor += curlen;
130 }
131 }
132
133 if (found)
134 {
135 /* Now we have read the line. */
136 status = NSS_STATUS_SUCCESS;
137 result->cursor = result->data;
138 result->first = 1;
139 break;
140 }
141 }
142
143 the_end:
144 /* We don't need the file and the line buffer anymore. */
145 free (line);
146 fclose (fp);
147
148 if (status != NSS_STATUS_SUCCESS)
149 _nss_files_endnetgrent (result);
150 }
151
152 return status;
153}
154
155
156enum nss_status
157_nss_files_endnetgrent (struct __netgrent *result)
158{
159 /* Free allocated memory for data if some is present. */
160 free (result->data);
161 result->data = NULL;
162 result->data_size = 0;
163 result->cursor = NULL;
164 return NSS_STATUS_SUCCESS;
165}
166libnss_files_hidden_def (_nss_files_endnetgrent)
167
168static char *
169strip_whitespace (char *str)
170{
171 char *cp = str;
172
173 /* Skip leading spaces. */
174 while (isspace (*cp))
175 cp++;
176
177 str = cp;
178 while (*cp != '\0' && ! isspace(*cp))
179 cp++;
180
181 /* Null-terminate, stripping off any trailing spaces. */
182 *cp = '\0';
183
184 return *str == '\0' ? NULL : str;
185}
186
187enum nss_status
188_nss_netgroup_parseline (char **cursor, struct __netgrent *result,
189 char *buffer, size_t buflen, int *errnop)
190{
191 enum nss_status status;
192 const char *host, *user, *domain;
193 char *cp = *cursor;
194
195 /* Some sanity checks. */
196 if (cp == NULL)
197 return NSS_STATUS_NOTFOUND;
198
199 /* First skip leading spaces. */
200 while (isspace (*cp))
201 ++cp;
202
203 if (*cp != '(')
204 {
205 /* We have a list of other netgroups. */
206 char *name = cp;
207
208 while (*cp != '\0' && ! isspace (*cp))
209 ++cp;
210
211 if (name != cp)
212 {
213 /* It is another netgroup name. */
214 int last = *cp == '\0';
215
216 result->type = group_val;
217 result->val.group = name;
218 *cp = '\0';
219 if (! last)
220 ++cp;
221 *cursor = cp;
222 result->first = 0;
223
224 return NSS_STATUS_SUCCESS;
225 }
226
227 return result->first ? NSS_STATUS_NOTFOUND : NSS_STATUS_RETURN;
228 }
229
230 /* Match host name. */
231 host = ++cp;
232 while (*cp != ',')
233 if (*cp++ == '\0')
234 return result->first ? NSS_STATUS_NOTFOUND : NSS_STATUS_RETURN;
235
236 /* Match user name. */
237 user = ++cp;
238 while (*cp != ',')
239 if (*cp++ == '\0')
240 return result->first ? NSS_STATUS_NOTFOUND : NSS_STATUS_RETURN;
241
242 /* Match domain name. */
243 domain = ++cp;
244 while (*cp != ')')
245 if (*cp++ == '\0')
246 return result->first ? NSS_STATUS_NOTFOUND : NSS_STATUS_RETURN;
247 ++cp;
248
249
250 /* When we got here we have found an entry. Before we can copy it
251 to the private buffer we have to make sure it is big enough. */
252 if (cp - host > buflen)
253 {
254 *errnop = ERANGE;
255 status = NSS_STATUS_TRYAGAIN;
256 }
257 else
258 {
259 memcpy (buffer, host, cp - host);
260 result->type = triple_val;
261
262 buffer[(user - host) - 1] = '\0'; /* Replace ',' with '\0'. */
263 result->val.triple.host = strip_whitespace (buffer);
264
265 buffer[(domain - host) - 1] = '\0'; /* Replace ',' with '\0'. */
266 result->val.triple.user = strip_whitespace (buffer + (user - host));
267
268 buffer[(cp - host) - 1] = '\0'; /* Replace ')' with '\0'. */
269 result->val.triple.domain = strip_whitespace (buffer + (domain - host));
270
271 status = NSS_STATUS_SUCCESS;
272
273 /* Remember where we stopped reading. */
274 *cursor = cp;
275
276 result->first = 0;
277 }
278
279 return status;
280}
281libnss_files_hidden_def (_nss_netgroup_parseline)
282
283
284enum nss_status
285_nss_files_getnetgrent_r (struct __netgrent *result, char *buffer,
286 size_t buflen, int *errnop)
287{
288 enum nss_status status;
289
290 status = _nss_netgroup_parseline (&result->cursor, result, buffer, buflen,
291 errnop);
292
293 return status;
294}
295