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f6903667 AK |
1 | /* |
2 | * nonlocal-group.c | |
3 | * group database for nss_nonlocal proxy | |
4 | * | |
96a1ee0f AK |
5 | * Copyright © 2007–2010 Anders Kaseorg <andersk@mit.edu> and Tim |
6 | * Abbott <tabbott@mit.edu> | |
f6903667 | 7 | * |
96a1ee0f | 8 | * This file is part of nss_nonlocal. |
f6903667 | 9 | * |
96a1ee0f AK |
10 | * nss_nonlocal is free software; you can redistribute it and/or |
11 | * modify it under the terms of the GNU Lesser General Public License | |
12 | * as published by the Free Software Foundation; either version 2.1 of | |
13 | * the License, or (at your option) any later version. | |
f6903667 | 14 | * |
96a1ee0f AK |
15 | * nss_nonlocal is distributed in the hope that it will be useful, but |
16 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * Lesser General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU Lesser General Public | |
21 | * License along with nss_nonlocal; if not, write to the Free Software | |
22 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
23 | * 02110-1301 USA | |
f6903667 AK |
24 | */ |
25 | ||
26 | #define _GNU_SOURCE | |
27 | #include <sys/types.h> | |
28 | #include <unistd.h> | |
29 | #include <stdlib.h> | |
30 | #include <stdint.h> | |
31 | #include <string.h> | |
32 | #include <dlfcn.h> | |
33 | #include <stdio.h> | |
34 | #include <syslog.h> | |
35 | #include <errno.h> | |
36 | #include <grp.h> | |
37 | #include <nss.h> | |
38 | #include "nsswitch-internal.h" | |
39 | #include "nonlocal.h" | |
40 | ||
48479fc7 TA |
41 | #define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users" |
42 | #define MAGIC_LOCAL_GROUPNAME "nss-local-users" | |
f7293a54 | 43 | |
f6903667 | 44 | |
c1812233 AK |
45 | enum nss_status |
46 | _nss_nonlocal_getgrnam_r(const char *name, struct group *grp, | |
47 | char *buffer, size_t buflen, int *errnop); | |
48 | ||
49 | enum nss_status | |
50 | _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp, | |
51 | char *buffer, size_t buflen, int *errnop); | |
52 | ||
53 | ||
cbb0e3ea AK |
54 | static service_user *__nss_group_nonlocal_database; |
55 | ||
56 | static int | |
57 | internal_function | |
58 | __nss_group_nonlocal_lookup(service_user **ni, const char *fct_name, | |
59 | void **fctp) | |
f6903667 | 60 | { |
cbb0e3ea AK |
61 | if (__nss_group_nonlocal_database == NULL |
62 | && __nss_database_lookup("group_nonlocal", NULL, NULL, | |
63 | &__nss_group_nonlocal_database) < 0) | |
64 | return -1; | |
65 | ||
66 | *ni = __nss_group_nonlocal_database; | |
48479fc7 | 67 | |
cbb0e3ea AK |
68 | *fctp = __nss_lookup_function(*ni, fct_name); |
69 | return 0; | |
f6903667 AK |
70 | } |
71 | ||
72 | ||
f6903667 AK |
73 | enum nss_status |
74 | check_nonlocal_gid(const char *user, gid_t gid, int *errnop) | |
75 | { | |
30fb3957 | 76 | enum nss_status status; |
f7293a54 | 77 | struct group gbuf; |
cbb0e3ea | 78 | char *buf; |
8870ee9c | 79 | size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX); |
cbb0e3ea AK |
80 | const struct walk_nss w = { |
81 | .lookup = &__nss_group_lookup, .fct_name = "getgrgid_r", | |
82 | .status = &status, .errnop = errnop, .buf = &buf, .buflen = &buflen | |
83 | }; | |
84 | const __typeof__(&_nss_nonlocal_getgrgid_r) self = &_nss_nonlocal_getgrgid_r; | |
85 | #define args (gid, &gbuf, buf, buflen, errnop) | |
86 | #include "walk_nss.h" | |
87 | #undef args | |
30fb3957 AK |
88 | |
89 | if (status == NSS_STATUS_SUCCESS) { | |
21b6ddd9 | 90 | syslog(LOG_DEBUG, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user); |
cbb0e3ea | 91 | free(buf); |
f6903667 | 92 | status = NSS_STATUS_NOTFOUND; |
30fb3957 AK |
93 | } else if (status != NSS_STATUS_TRYAGAIN) { |
94 | status = NSS_STATUS_SUCCESS; | |
f6903667 | 95 | } |
30fb3957 | 96 | |
f6903667 AK |
97 | return status; |
98 | } | |
99 | ||
cf338316 AK |
100 | enum nss_status |
101 | check_nonlocal_group(const char *user, struct group *grp, int *errnop) | |
102 | { | |
a07a7616 AK |
103 | enum nss_status status = NSS_STATUS_SUCCESS; |
104 | int old_errno = errno; | |
105 | char *end; | |
106 | unsigned long gid; | |
107 | ||
108 | errno = 0; | |
109 | gid = strtoul(grp->gr_name, &end, 10); | |
f4061d47 AK |
110 | if (errno == 0 && *end == '\0' && (gid_t)gid == gid) { |
111 | errno = old_errno; | |
a07a7616 | 112 | status = check_nonlocal_gid(user, gid, errnop); |
f4061d47 AK |
113 | } else |
114 | errno = old_errno; | |
a07a7616 AK |
115 | if (status != NSS_STATUS_SUCCESS) |
116 | return status; | |
117 | ||
cf338316 AK |
118 | return check_nonlocal_gid(user, grp->gr_gid, errnop); |
119 | } | |
120 | ||
48479fc7 | 121 | enum nss_status |
8aa9014e | 122 | get_local_group(const char *name, struct group *grp, char **buffer, int *errnop) |
48479fc7 | 123 | { |
30fb3957 | 124 | enum nss_status status; |
cbb0e3ea AK |
125 | size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX); |
126 | const struct walk_nss w = { | |
127 | .lookup = &__nss_group_lookup, .fct_name = "getgrnam_r", | |
128 | .status = &status, .errnop = errnop, .buf = buffer, .buflen = &buflen | |
129 | }; | |
130 | const __typeof__(&_nss_nonlocal_getgrnam_r) self = &_nss_nonlocal_getgrnam_r; | |
131 | #define args (name, grp, *buffer, buflen, errnop) | |
132 | #include "walk_nss.h" | |
133 | #undef args | |
48479fc7 TA |
134 | return status; |
135 | } | |
f6903667 | 136 | |
cbb0e3ea | 137 | static service_user *grent_startp, *grent_nip; |
f6903667 AK |
138 | static void *grent_fct_start; |
139 | static union { | |
140 | enum nss_status (*l)(struct group *grp, char *buffer, size_t buflen, | |
141 | int *errnop); | |
142 | void *ptr; | |
143 | } grent_fct; | |
144 | static const char *grent_fct_name = "getgrent_r"; | |
145 | ||
146 | enum nss_status | |
147 | _nss_nonlocal_setgrent(int stayopen) | |
148 | { | |
f6903667 | 149 | enum nss_status status; |
cbb0e3ea AK |
150 | const struct walk_nss w = { |
151 | .lookup = &__nss_group_nonlocal_lookup, .fct_name = "setgrent", | |
152 | .status = &status | |
153 | }; | |
154 | const __typeof__(&_nss_nonlocal_setgrent) self = NULL; | |
155 | #define args (stayopen) | |
156 | #include "walk_nss.h" | |
157 | #undef args | |
f6903667 AK |
158 | if (status != NSS_STATUS_SUCCESS) |
159 | return status; | |
160 | ||
f6903667 | 161 | if (grent_fct_start == NULL) |
cbb0e3ea AK |
162 | __nss_group_nonlocal_lookup(&grent_startp, grent_fct_name, |
163 | &grent_fct_start); | |
164 | grent_nip = grent_startp; | |
f6903667 AK |
165 | grent_fct.ptr = grent_fct_start; |
166 | return NSS_STATUS_SUCCESS; | |
167 | } | |
168 | ||
169 | enum nss_status | |
170 | _nss_nonlocal_endgrent(void) | |
171 | { | |
f6903667 | 172 | enum nss_status status; |
cbb0e3ea AK |
173 | const struct walk_nss w = { |
174 | .lookup = &__nss_group_nonlocal_lookup, .fct_name = "endgrent", | |
175 | .status = &status | |
176 | }; | |
177 | const __typeof__(&_nss_nonlocal_endgrent) self = NULL; | |
f6903667 AK |
178 | |
179 | grent_nip = NULL; | |
180 | ||
cbb0e3ea AK |
181 | #define args () |
182 | #include "walk_nss.h" | |
183 | #undef args | |
f6903667 AK |
184 | return status; |
185 | } | |
186 | ||
187 | enum nss_status | |
188 | _nss_nonlocal_getgrent_r(struct group *grp, char *buffer, size_t buflen, | |
189 | int *errnop) | |
190 | { | |
191 | enum nss_status status; | |
a360549e TA |
192 | |
193 | char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV); | |
c1812233 | 194 | if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0') |
a360549e TA |
195 | return NSS_STATUS_UNAVAIL; |
196 | ||
f6903667 AK |
197 | if (grent_nip == NULL) { |
198 | status = _nss_nonlocal_setgrent(0); | |
199 | if (status != NSS_STATUS_SUCCESS) | |
200 | return status; | |
201 | } | |
202 | do { | |
203 | if (grent_fct.ptr == NULL) | |
204 | status = NSS_STATUS_UNAVAIL; | |
205 | else { | |
206 | int nonlocal_errno; | |
207 | do | |
208 | status = DL_CALL_FCT(grent_fct.l, (grp, buffer, buflen, errnop)); | |
209 | while (status == NSS_STATUS_SUCCESS && | |
cf338316 | 210 | check_nonlocal_group("(unknown)", grp, &nonlocal_errno) != NSS_STATUS_SUCCESS); |
f6903667 AK |
211 | } |
212 | if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) | |
213 | return status; | |
214 | ||
215 | if (status == NSS_STATUS_SUCCESS) | |
216 | return NSS_STATUS_SUCCESS; | |
217 | } while (__nss_next(&grent_nip, grent_fct_name, &grent_fct.ptr, status, 0) == 0); | |
218 | ||
219 | grent_nip = NULL; | |
220 | return NSS_STATUS_NOTFOUND; | |
221 | } | |
222 | ||
223 | ||
224 | enum nss_status | |
225 | _nss_nonlocal_getgrnam_r(const char *name, struct group *grp, | |
226 | char *buffer, size_t buflen, int *errnop) | |
227 | { | |
f6903667 | 228 | enum nss_status status; |
cbb0e3ea AK |
229 | const struct walk_nss w = { |
230 | .lookup = &__nss_group_nonlocal_lookup, .fct_name = "getgrnam_r", | |
231 | .status = &status, .errnop = errnop | |
232 | }; | |
233 | const __typeof__(&_nss_nonlocal_getgrnam_r) self = NULL; | |
f6903667 | 234 | |
a360549e | 235 | char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV); |
c1812233 | 236 | if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0') |
48479fc7 TA |
237 | return NSS_STATUS_UNAVAIL; |
238 | ||
cbb0e3ea AK |
239 | #define args (name, grp, buffer, buflen, errnop) |
240 | #include "walk_nss.h" | |
241 | #undef args | |
f6903667 AK |
242 | if (status != NSS_STATUS_SUCCESS) |
243 | return status; | |
244 | ||
22562df0 AK |
245 | if (strcmp(name, grp->gr_name) != 0) { |
246 | syslog(LOG_ERR, "nss_nonlocal: discarding group %s from lookup for group %s\n", grp->gr_name, name); | |
247 | return NSS_STATUS_NOTFOUND; | |
248 | } | |
249 | ||
cf338316 | 250 | return check_nonlocal_group(name, grp, errnop); |
f6903667 AK |
251 | } |
252 | ||
253 | enum nss_status | |
254 | _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp, | |
255 | char *buffer, size_t buflen, int *errnop) | |
256 | { | |
f6903667 | 257 | enum nss_status status; |
cbb0e3ea AK |
258 | const struct walk_nss w = { |
259 | .lookup = &__nss_group_nonlocal_lookup, .fct_name = "getgrgid_r", | |
260 | .status = &status, .errnop = errnop | |
261 | }; | |
262 | const __typeof__(&_nss_nonlocal_getgrgid_r) self = NULL; | |
f6903667 | 263 | |
a360549e | 264 | char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV); |
c1812233 | 265 | if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0') |
f6903667 AK |
266 | return NSS_STATUS_UNAVAIL; |
267 | ||
cbb0e3ea AK |
268 | #define args (gid, grp, buffer, buflen, errnop) |
269 | #include "walk_nss.h" | |
270 | #undef args | |
f6903667 AK |
271 | if (status != NSS_STATUS_SUCCESS) |
272 | return status; | |
273 | ||
8027fdc4 AK |
274 | if (gid != grp->gr_gid) { |
275 | syslog(LOG_ERR, "nss_nonlocal: discarding gid %d from lookup for gid %d\n", grp->gr_gid, gid); | |
276 | return NSS_STATUS_NOTFOUND; | |
277 | } | |
278 | ||
cf338316 | 279 | return check_nonlocal_group(grp->gr_name, grp, errnop); |
f6903667 AK |
280 | } |
281 | ||
dfc6e292 AK |
282 | static bool |
283 | add_group(gid_t group, long int *start, long int *size, gid_t **groupsp, | |
284 | long int limit, int *errnop, enum nss_status *status) | |
285 | { | |
286 | int i, old_errno = errno; | |
287 | for (i = 0; i < *start; ++i) | |
288 | if ((*groupsp)[i] == group) | |
289 | return true; | |
290 | if (*start + 1 > *size) { | |
291 | gid_t *newgroups; | |
292 | long int newsize = 2 * *size; | |
293 | if (limit > 0) { | |
294 | if (*size >= limit) { | |
295 | *status = NSS_STATUS_SUCCESS; | |
296 | return false; | |
297 | } | |
298 | if (newsize > limit) | |
299 | newsize = limit; | |
300 | } | |
301 | newgroups = realloc(*groupsp, newsize * sizeof((*groupsp)[0])); | |
302 | errno = old_errno; | |
303 | if (newgroups == NULL) { | |
304 | *errnop = ENOMEM; | |
305 | *status = NSS_STATUS_TRYAGAIN; | |
306 | return false; | |
307 | } | |
308 | *groupsp = newgroups; | |
309 | *size = newsize; | |
310 | } | |
311 | (*groupsp)[(*start)++] = group; | |
312 | return true; | |
313 | } | |
314 | ||
f6903667 AK |
315 | enum nss_status |
316 | _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, | |
317 | long int *size, gid_t **groupsp, long int limit, | |
318 | int *errnop) | |
319 | { | |
f6903667 | 320 | enum nss_status status; |
cbb0e3ea AK |
321 | const struct walk_nss w = { |
322 | .lookup = &__nss_group_nonlocal_lookup, .fct_name = "initgroups_dyn", | |
323 | .status = &status, .errnop = errnop | |
324 | }; | |
325 | const __typeof__(&_nss_nonlocal_initgroups_dyn) self = NULL; | |
1e78305d AK |
326 | |
327 | struct group local_users_group, nonlocal_users_group; | |
b3831d60 | 328 | bool is_nonlocal = true; |
1e78305d | 329 | char *buffer; |
d7bf1d11 | 330 | int in, out, i; |
48479fc7 | 331 | |
1e78305d | 332 | /* Check that the user is a nonlocal user before adding any groups. */ |
48479fc7 | 333 | status = check_nonlocal_user(user, errnop); |
3010a54b | 334 | if (status == NSS_STATUS_TRYAGAIN) { |
48479fc7 | 335 | return status; |
3010a54b | 336 | } else if (status != NSS_STATUS_SUCCESS) { |
b3831d60 | 337 | is_nonlocal = false; |
48479fc7 | 338 | |
3010a54b AK |
339 | status = get_local_group(MAGIC_LOCAL_GROUPNAME, |
340 | &local_users_group, &buffer, errnop); | |
341 | if (status == NSS_STATUS_SUCCESS) { | |
342 | free(buffer); | |
343 | if (!add_group(local_users_group.gr_gid, start, size, groupsp, | |
344 | limit, errnop, &status)) | |
345 | return status; | |
346 | } else if (status == NSS_STATUS_TRYAGAIN) { | |
dfc6e292 | 347 | return status; |
3010a54b AK |
348 | } else { |
349 | syslog(LOG_WARNING, | |
350 | "nss_nonlocal: Group %s does not exist locally!", | |
351 | MAGIC_LOCAL_GROUPNAME); | |
352 | } | |
1e78305d | 353 | } else { |
1e78305d | 354 | status = get_local_group(MAGIC_NONLOCAL_GROUPNAME, |
8aa9014e | 355 | &nonlocal_users_group, &buffer, errnop); |
5879a696 | 356 | if (status == NSS_STATUS_SUCCESS) { |
dc94c928 | 357 | free(buffer); |
dfc6e292 AK |
358 | if (!add_group(nonlocal_users_group.gr_gid, start, size, groupsp, |
359 | limit, errnop, &status)) | |
360 | return status; | |
8aa9014e | 361 | } else if (status == NSS_STATUS_TRYAGAIN) { |
5879a696 AK |
362 | return status; |
363 | } else { | |
1e78305d AK |
364 | syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!", |
365 | MAGIC_NONLOCAL_GROUPNAME); | |
1e78305d | 366 | } |
48479fc7 | 367 | } |
f6903667 | 368 | |
b3831d60 | 369 | if (!is_nonlocal) |
1e78305d AK |
370 | return NSS_STATUS_SUCCESS; |
371 | ||
d7bf1d11 | 372 | in = out = *start; |
1e78305d | 373 | |
cbb0e3ea AK |
374 | #define args (user, group, start, size, groupsp, limit, errnop) |
375 | #include "walk_nss.h" | |
376 | #undef args | |
f6903667 AK |
377 | if (status != NSS_STATUS_SUCCESS) |
378 | return status; | |
379 | ||
380 | for (; in < *start; ++in) { | |
381 | int nonlocal_errno = *errnop; | |
382 | ||
383 | for (i = 0; i < out; ++i) | |
384 | if ((*groupsp)[i] == (*groupsp)[in]) | |
385 | break; | |
386 | if (i < out) | |
387 | continue; | |
388 | ||
389 | status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno); | |
390 | if (status == NSS_STATUS_SUCCESS) { | |
1e78305d | 391 | (*groupsp)[out++] = (*groupsp)[in]; |
5879a696 | 392 | } else if (status == NSS_STATUS_TRYAGAIN) { |
f6903667 AK |
393 | *start = out; |
394 | *errnop = nonlocal_errno; | |
395 | return status; | |
396 | } | |
397 | } | |
398 | ||
399 | *start = out; | |
400 | return NSS_STATUS_SUCCESS; | |
401 | } |