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 | |
32 | libnss_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 | |
55 | enum 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 | |
156 | enum 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 | } |
166 | libnss_files_hidden_def (_nss_files_endnetgrent) |
167 | |
168 | static char * |
169 | strip_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 | |
187 | enum 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 | } |
281 | libnss_files_hidden_def (_nss_netgroup_parseline) |
282 | |
283 | |
284 | enum 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 | |