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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 | |
dc397f8f | 27 | |
f6903667 | 28 | #include <sys/types.h> |
f6903667 | 29 | #include <dlfcn.h> |
f6903667 AK |
30 | #include <errno.h> |
31 | #include <grp.h> | |
32 | #include <nss.h> | |
dc397f8f AK |
33 | #include <pwd.h> |
34 | #include <stdbool.h> | |
35 | #include <stddef.h> | |
36 | #include <stdlib.h> | |
37 | #include <string.h> | |
38 | #include <syslog.h> | |
39 | #include <unistd.h> | |
40 | ||
f6903667 AK |
41 | #include "nsswitch-internal.h" |
42 | #include "nonlocal.h" | |
43 | ||
6ca16423 AK |
44 | /* |
45 | * If the MAGIC_NONLOCAL_GROUPNAME local group exists, then nonlocal | |
34cfeb28 AK |
46 | * users will be automatically added to it. Furthermore, if a local |
47 | * user is added to this group, then that user will inherit any | |
775f7dc3 AK |
48 | * nonlocal gids from a nonlocal user of the same name, as |
49 | * supplementary gids. | |
6ca16423 | 50 | */ |
48479fc7 | 51 | #define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users" |
6ca16423 AK |
52 | |
53 | /* | |
54 | * If the MAGIC_LOCAL_GROUPNAME local group exists, then local users | |
55 | * will be automatically added to it. | |
56 | */ | |
48479fc7 | 57 | #define MAGIC_LOCAL_GROUPNAME "nss-local-users" |
f7293a54 | 58 | |
25468b96 AK |
59 | /* |
60 | * If the MAGIC_NONLOCAL_USERNAME local user is added to a local | |
61 | * group, then the local group will inherit the nonlocal membership of | |
62 | * a group of the same gid. | |
63 | */ | |
64 | #define MAGIC_NONLOCAL_USERNAME "nss-nonlocal-users" | |
65 | ||
f6903667 | 66 | |
c1812233 AK |
67 | enum nss_status |
68 | _nss_nonlocal_getgrnam_r(const char *name, struct group *grp, | |
69 | char *buffer, size_t buflen, int *errnop); | |
70 | ||
71 | enum nss_status | |
72 | _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp, | |
73 | char *buffer, size_t buflen, int *errnop); | |
74 | ||
75 | ||
cbb0e3ea AK |
76 | static service_user *__nss_group_nonlocal_database; |
77 | ||
78 | static int | |
79 | internal_function | |
80 | __nss_group_nonlocal_lookup(service_user **ni, const char *fct_name, | |
81 | void **fctp) | |
f6903667 | 82 | { |
cbb0e3ea AK |
83 | if (__nss_group_nonlocal_database == NULL |
84 | && __nss_database_lookup("group_nonlocal", NULL, NULL, | |
85 | &__nss_group_nonlocal_database) < 0) | |
86 | return -1; | |
87 | ||
88 | *ni = __nss_group_nonlocal_database; | |
48479fc7 | 89 | |
cbb0e3ea AK |
90 | *fctp = __nss_lookup_function(*ni, fct_name); |
91 | return 0; | |
f6903667 AK |
92 | } |
93 | ||
94 | ||
f6903667 | 95 | enum nss_status |
25468b96 | 96 | check_nonlocal_gid(const char *user, const char *group, gid_t gid, int *errnop) |
f6903667 | 97 | { |
30fb3957 | 98 | enum nss_status status; |
f7293a54 | 99 | struct group gbuf; |
cbb0e3ea | 100 | char *buf; |
8870ee9c | 101 | size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX); |
cbb0e3ea AK |
102 | const struct walk_nss w = { |
103 | .lookup = &__nss_group_lookup, .fct_name = "getgrgid_r", | |
104 | .status = &status, .errnop = errnop, .buf = &buf, .buflen = &buflen | |
105 | }; | |
106 | const __typeof__(&_nss_nonlocal_getgrgid_r) self = &_nss_nonlocal_getgrgid_r; | |
107 | #define args (gid, &gbuf, buf, buflen, errnop) | |
108 | #include "walk_nss.h" | |
109 | #undef args | |
30fb3957 | 110 | |
25468b96 AK |
111 | if (status == NSS_STATUS_TRYAGAIN) |
112 | return status; | |
113 | else if (status != NSS_STATUS_SUCCESS) | |
114 | return NSS_STATUS_SUCCESS; | |
115 | ||
116 | if (group == NULL || strcmp(gbuf.gr_name, group) == 0) { | |
117 | char *const *mem; | |
118 | for (mem = gbuf.gr_mem; *mem != NULL; mem++) | |
119 | if (strcmp(*mem, MAGIC_NONLOCAL_USERNAME) == 0) { | |
120 | status = check_nonlocal_user(*mem, errnop); | |
121 | if (status == NSS_STATUS_TRYAGAIN) { | |
122 | free(buf); | |
123 | return status; | |
124 | } else if (status == NSS_STATUS_NOTFOUND) { | |
125 | free(buf); | |
126 | return NSS_STATUS_SUCCESS; | |
127 | } | |
128 | break; | |
129 | } | |
f6903667 | 130 | } |
30fb3957 | 131 | |
25468b96 AK |
132 | syslog(LOG_DEBUG, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user); |
133 | free(buf); | |
134 | return NSS_STATUS_NOTFOUND; | |
f6903667 AK |
135 | } |
136 | ||
cf338316 AK |
137 | enum nss_status |
138 | check_nonlocal_group(const char *user, struct group *grp, int *errnop) | |
139 | { | |
a07a7616 AK |
140 | enum nss_status status = NSS_STATUS_SUCCESS; |
141 | int old_errno = errno; | |
142 | char *end; | |
143 | unsigned long gid; | |
144 | ||
145 | errno = 0; | |
146 | gid = strtoul(grp->gr_name, &end, 10); | |
f4061d47 AK |
147 | if (errno == 0 && *end == '\0' && (gid_t)gid == gid) { |
148 | errno = old_errno; | |
25468b96 | 149 | status = check_nonlocal_gid(user, grp->gr_name, gid, errnop); |
f4061d47 AK |
150 | } else |
151 | errno = old_errno; | |
a07a7616 AK |
152 | if (status != NSS_STATUS_SUCCESS) |
153 | return status; | |
154 | ||
25468b96 | 155 | return check_nonlocal_gid(user, grp->gr_name, grp->gr_gid, errnop); |
cf338316 AK |
156 | } |
157 | ||
48479fc7 | 158 | enum nss_status |
8aa9014e | 159 | get_local_group(const char *name, struct group *grp, char **buffer, int *errnop) |
48479fc7 | 160 | { |
30fb3957 | 161 | enum nss_status status; |
cbb0e3ea AK |
162 | size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX); |
163 | const struct walk_nss w = { | |
164 | .lookup = &__nss_group_lookup, .fct_name = "getgrnam_r", | |
165 | .status = &status, .errnop = errnop, .buf = buffer, .buflen = &buflen | |
166 | }; | |
167 | const __typeof__(&_nss_nonlocal_getgrnam_r) self = &_nss_nonlocal_getgrnam_r; | |
168 | #define args (name, grp, *buffer, buflen, errnop) | |
169 | #include "walk_nss.h" | |
170 | #undef args | |
48479fc7 TA |
171 | return status; |
172 | } | |
f6903667 | 173 | |
48939704 | 174 | static bool grent_initialized = false; |
cbb0e3ea | 175 | static service_user *grent_startp, *grent_nip; |
f6903667 AK |
176 | static void *grent_fct_start; |
177 | static union { | |
178 | enum nss_status (*l)(struct group *grp, char *buffer, size_t buflen, | |
179 | int *errnop); | |
180 | void *ptr; | |
181 | } grent_fct; | |
182 | static const char *grent_fct_name = "getgrent_r"; | |
183 | ||
184 | enum nss_status | |
185 | _nss_nonlocal_setgrent(int stayopen) | |
186 | { | |
f6903667 | 187 | enum nss_status status; |
cbb0e3ea AK |
188 | const struct walk_nss w = { |
189 | .lookup = &__nss_group_nonlocal_lookup, .fct_name = "setgrent", | |
190 | .status = &status | |
191 | }; | |
192 | const __typeof__(&_nss_nonlocal_setgrent) self = NULL; | |
193 | #define args (stayopen) | |
194 | #include "walk_nss.h" | |
195 | #undef args | |
f6903667 AK |
196 | if (status != NSS_STATUS_SUCCESS) |
197 | return status; | |
198 | ||
48939704 | 199 | if (!grent_initialized) { |
cbb0e3ea AK |
200 | __nss_group_nonlocal_lookup(&grent_startp, grent_fct_name, |
201 | &grent_fct_start); | |
48939704 AK |
202 | __sync_synchronize(); |
203 | grent_initialized = true; | |
204 | } | |
cbb0e3ea | 205 | grent_nip = grent_startp; |
f6903667 AK |
206 | grent_fct.ptr = grent_fct_start; |
207 | return NSS_STATUS_SUCCESS; | |
208 | } | |
209 | ||
210 | enum nss_status | |
211 | _nss_nonlocal_endgrent(void) | |
212 | { | |
f6903667 | 213 | enum nss_status status; |
cbb0e3ea AK |
214 | const struct walk_nss w = { |
215 | .lookup = &__nss_group_nonlocal_lookup, .fct_name = "endgrent", | |
23ca0ded | 216 | .status = &status, .all_values = 1, |
cbb0e3ea AK |
217 | }; |
218 | const __typeof__(&_nss_nonlocal_endgrent) self = NULL; | |
f6903667 AK |
219 | |
220 | grent_nip = NULL; | |
221 | ||
cbb0e3ea AK |
222 | #define args () |
223 | #include "walk_nss.h" | |
224 | #undef args | |
f6903667 AK |
225 | return status; |
226 | } | |
227 | ||
228 | enum nss_status | |
229 | _nss_nonlocal_getgrent_r(struct group *grp, char *buffer, size_t buflen, | |
230 | int *errnop) | |
231 | { | |
232 | enum nss_status status; | |
a360549e TA |
233 | |
234 | char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV); | |
c1812233 | 235 | if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0') |
a360549e TA |
236 | return NSS_STATUS_UNAVAIL; |
237 | ||
f6903667 AK |
238 | if (grent_nip == NULL) { |
239 | status = _nss_nonlocal_setgrent(0); | |
240 | if (status != NSS_STATUS_SUCCESS) | |
241 | return status; | |
242 | } | |
243 | do { | |
244 | if (grent_fct.ptr == NULL) | |
245 | status = NSS_STATUS_UNAVAIL; | |
246 | else { | |
247 | int nonlocal_errno; | |
248 | do | |
249 | status = DL_CALL_FCT(grent_fct.l, (grp, buffer, buflen, errnop)); | |
250 | while (status == NSS_STATUS_SUCCESS && | |
cf338316 | 251 | check_nonlocal_group("(unknown)", grp, &nonlocal_errno) != NSS_STATUS_SUCCESS); |
f6903667 AK |
252 | } |
253 | if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) | |
254 | return status; | |
255 | ||
256 | if (status == NSS_STATUS_SUCCESS) | |
257 | return NSS_STATUS_SUCCESS; | |
258 | } while (__nss_next(&grent_nip, grent_fct_name, &grent_fct.ptr, status, 0) == 0); | |
259 | ||
260 | grent_nip = NULL; | |
261 | return NSS_STATUS_NOTFOUND; | |
262 | } | |
263 | ||
264 | ||
265 | enum nss_status | |
266 | _nss_nonlocal_getgrnam_r(const char *name, struct group *grp, | |
267 | char *buffer, size_t buflen, int *errnop) | |
268 | { | |
f6903667 | 269 | enum nss_status status; |
cbb0e3ea AK |
270 | const struct walk_nss w = { |
271 | .lookup = &__nss_group_nonlocal_lookup, .fct_name = "getgrnam_r", | |
272 | .status = &status, .errnop = errnop | |
273 | }; | |
274 | const __typeof__(&_nss_nonlocal_getgrnam_r) self = NULL; | |
f6903667 | 275 | |
a360549e | 276 | char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV); |
c1812233 | 277 | if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0') |
48479fc7 TA |
278 | return NSS_STATUS_UNAVAIL; |
279 | ||
cbb0e3ea AK |
280 | #define args (name, grp, buffer, buflen, errnop) |
281 | #include "walk_nss.h" | |
282 | #undef args | |
f6903667 AK |
283 | if (status != NSS_STATUS_SUCCESS) |
284 | return status; | |
285 | ||
22562df0 AK |
286 | if (strcmp(name, grp->gr_name) != 0) { |
287 | syslog(LOG_ERR, "nss_nonlocal: discarding group %s from lookup for group %s\n", grp->gr_name, name); | |
288 | return NSS_STATUS_NOTFOUND; | |
289 | } | |
290 | ||
cf338316 | 291 | return check_nonlocal_group(name, grp, errnop); |
f6903667 AK |
292 | } |
293 | ||
294 | enum nss_status | |
295 | _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp, | |
296 | char *buffer, size_t buflen, int *errnop) | |
297 | { | |
f6903667 | 298 | enum nss_status status; |
cbb0e3ea AK |
299 | const struct walk_nss w = { |
300 | .lookup = &__nss_group_nonlocal_lookup, .fct_name = "getgrgid_r", | |
301 | .status = &status, .errnop = errnop | |
302 | }; | |
303 | const __typeof__(&_nss_nonlocal_getgrgid_r) self = NULL; | |
f6903667 | 304 | |
a360549e | 305 | char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV); |
c1812233 | 306 | if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0') |
f6903667 AK |
307 | return NSS_STATUS_UNAVAIL; |
308 | ||
cbb0e3ea AK |
309 | #define args (gid, grp, buffer, buflen, errnop) |
310 | #include "walk_nss.h" | |
311 | #undef args | |
f6903667 AK |
312 | if (status != NSS_STATUS_SUCCESS) |
313 | return status; | |
314 | ||
8027fdc4 AK |
315 | if (gid != grp->gr_gid) { |
316 | syslog(LOG_ERR, "nss_nonlocal: discarding gid %d from lookup for gid %d\n", grp->gr_gid, gid); | |
317 | return NSS_STATUS_NOTFOUND; | |
318 | } | |
319 | ||
cf338316 | 320 | return check_nonlocal_group(grp->gr_name, grp, errnop); |
f6903667 AK |
321 | } |
322 | ||
dfc6e292 AK |
323 | static bool |
324 | add_group(gid_t group, long int *start, long int *size, gid_t **groupsp, | |
325 | long int limit, int *errnop, enum nss_status *status) | |
326 | { | |
327 | int i, old_errno = errno; | |
328 | for (i = 0; i < *start; ++i) | |
329 | if ((*groupsp)[i] == group) | |
330 | return true; | |
331 | if (*start + 1 > *size) { | |
332 | gid_t *newgroups; | |
333 | long int newsize = 2 * *size; | |
334 | if (limit > 0) { | |
335 | if (*size >= limit) { | |
336 | *status = NSS_STATUS_SUCCESS; | |
337 | return false; | |
338 | } | |
339 | if (newsize > limit) | |
340 | newsize = limit; | |
341 | } | |
342 | newgroups = realloc(*groupsp, newsize * sizeof((*groupsp)[0])); | |
343 | errno = old_errno; | |
344 | if (newgroups == NULL) { | |
345 | *errnop = ENOMEM; | |
346 | *status = NSS_STATUS_TRYAGAIN; | |
347 | return false; | |
348 | } | |
349 | *groupsp = newgroups; | |
350 | *size = newsize; | |
351 | } | |
352 | (*groupsp)[(*start)++] = group; | |
353 | return true; | |
354 | } | |
355 | ||
f6903667 AK |
356 | enum nss_status |
357 | _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, | |
358 | long int *size, gid_t **groupsp, long int limit, | |
359 | int *errnop) | |
360 | { | |
f6903667 | 361 | enum nss_status status; |
cbb0e3ea AK |
362 | const struct walk_nss w = { |
363 | .lookup = &__nss_group_nonlocal_lookup, .fct_name = "initgroups_dyn", | |
23ca0ded | 364 | .status = &status, .all_values = 1, .errnop = errnop |
cbb0e3ea AK |
365 | }; |
366 | const __typeof__(&_nss_nonlocal_initgroups_dyn) self = NULL; | |
1e78305d AK |
367 | |
368 | struct group local_users_group, nonlocal_users_group; | |
b3831d60 | 369 | bool is_nonlocal = true; |
1e78305d | 370 | char *buffer; |
d7bf1d11 | 371 | int in, out, i; |
48479fc7 | 372 | |
34cfeb28 AK |
373 | /* Check that the user is a nonlocal user, or a member of the |
374 | * MAGIC_NONLOCAL_GROUPNAME group, before adding any groups. */ | |
48479fc7 | 375 | status = check_nonlocal_user(user, errnop); |
3010a54b | 376 | if (status == NSS_STATUS_TRYAGAIN) { |
48479fc7 | 377 | return status; |
3010a54b | 378 | } else if (status != NSS_STATUS_SUCCESS) { |
b3831d60 | 379 | is_nonlocal = false; |
48479fc7 | 380 | |
3010a54b AK |
381 | status = get_local_group(MAGIC_LOCAL_GROUPNAME, |
382 | &local_users_group, &buffer, errnop); | |
383 | if (status == NSS_STATUS_SUCCESS) { | |
384 | free(buffer); | |
385 | if (!add_group(local_users_group.gr_gid, start, size, groupsp, | |
386 | limit, errnop, &status)) | |
387 | return status; | |
388 | } else if (status == NSS_STATUS_TRYAGAIN) { | |
dfc6e292 | 389 | return status; |
3010a54b AK |
390 | } else { |
391 | syslog(LOG_WARNING, | |
392 | "nss_nonlocal: Group %s does not exist locally!", | |
393 | MAGIC_LOCAL_GROUPNAME); | |
394 | } | |
a4e1e153 AK |
395 | } |
396 | ||
397 | status = get_local_group(MAGIC_NONLOCAL_GROUPNAME, | |
398 | &nonlocal_users_group, &buffer, errnop); | |
399 | if (status == NSS_STATUS_SUCCESS) { | |
400 | free(buffer); | |
401 | if (is_nonlocal) { | |
dfc6e292 AK |
402 | if (!add_group(nonlocal_users_group.gr_gid, start, size, groupsp, |
403 | limit, errnop, &status)) | |
404 | return status; | |
34cfeb28 AK |
405 | } else { |
406 | int i; | |
407 | for (i = 0; i < *start; ++i) { | |
408 | if ((*groupsp)[i] == nonlocal_users_group.gr_gid) { | |
409 | is_nonlocal = true; | |
410 | break; | |
411 | } | |
412 | } | |
775f7dc3 AK |
413 | |
414 | if (is_nonlocal) { | |
415 | struct passwd pwbuf; | |
416 | char *buf; | |
417 | int nonlocal_errno = *errnop; | |
418 | status = get_nonlocal_passwd(user, &pwbuf, &buf, errnop); | |
419 | ||
420 | if (status == NSS_STATUS_SUCCESS) { | |
421 | nonlocal_errno = *errnop; | |
25468b96 | 422 | status = check_nonlocal_gid(user, NULL, pwbuf.pw_gid, |
775f7dc3 AK |
423 | &nonlocal_errno); |
424 | free(buf); | |
425 | } | |
426 | ||
427 | if (status == NSS_STATUS_SUCCESS) { | |
428 | if (!add_group(pwbuf.pw_gid, start, size, groupsp, limit, | |
429 | errnop, &status)) | |
430 | return status; | |
431 | } else if (status == NSS_STATUS_TRYAGAIN) { | |
432 | *errnop = nonlocal_errno; | |
433 | return status; | |
434 | } | |
435 | } | |
1e78305d | 436 | } |
a4e1e153 AK |
437 | } else if (status == NSS_STATUS_TRYAGAIN) { |
438 | if (is_nonlocal) | |
439 | return status; | |
440 | } else { | |
441 | syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!", | |
442 | MAGIC_NONLOCAL_GROUPNAME); | |
48479fc7 | 443 | } |
f6903667 | 444 | |
b3831d60 | 445 | if (!is_nonlocal) |
1e78305d AK |
446 | return NSS_STATUS_SUCCESS; |
447 | ||
d7bf1d11 | 448 | in = out = *start; |
1e78305d | 449 | |
cbb0e3ea AK |
450 | #define args (user, group, start, size, groupsp, limit, errnop) |
451 | #include "walk_nss.h" | |
452 | #undef args | |
18c6e9c7 AK |
453 | if (status == NSS_STATUS_NOTFOUND || status == NSS_STATUS_UNAVAIL) |
454 | return NSS_STATUS_SUCCESS; | |
455 | else if (status != NSS_STATUS_SUCCESS) | |
f6903667 AK |
456 | return status; |
457 | ||
458 | for (; in < *start; ++in) { | |
459 | int nonlocal_errno = *errnop; | |
460 | ||
461 | for (i = 0; i < out; ++i) | |
462 | if ((*groupsp)[i] == (*groupsp)[in]) | |
463 | break; | |
464 | if (i < out) | |
465 | continue; | |
466 | ||
25468b96 AK |
467 | status = check_nonlocal_gid(user, NULL, (*groupsp)[in], |
468 | &nonlocal_errno); | |
f6903667 | 469 | if (status == NSS_STATUS_SUCCESS) { |
1e78305d | 470 | (*groupsp)[out++] = (*groupsp)[in]; |
5879a696 | 471 | } else if (status == NSS_STATUS_TRYAGAIN) { |
f6903667 AK |
472 | *start = out; |
473 | *errnop = nonlocal_errno; | |
474 | return status; | |
475 | } | |
476 | } | |
477 | ||
478 | *start = out; | |
479 | return NSS_STATUS_SUCCESS; | |
480 | } |