3 * group database for nss_nonlocal proxy
5 * Copyright © 2007 Anders Kaseorg <andersk@mit.edu> and Tim Abbott
8 * Permission is hereby granted, free of charge, to any person
9 * obtaining a copy of this software and associated documentation
10 * files (the "Software"), to deal in the Software without
11 * restriction, including without limitation the rights to use, copy,
12 * modify, merge, publish, distribute, sublicense, and/or sell copies
13 * of the Software, and to permit persons to whom the Software is
14 * furnished to do so, subject to the following conditions:
16 * The above copyright notice and this permission notice shall be
17 * included in all copies or substantial portions of the Software.
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
23 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
24 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
25 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 #include <sys/types.h>
41 #include "nsswitch-internal.h"
44 #define MAGIC_LOCAL_GR_BUFLEN (sysconf(_SC_GETGR_R_SIZE_MAX) + 7)
45 #define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users"
46 #define MAGIC_LOCAL_GROUPNAME "nss-local-users"
50 nss_group_nonlocal_database(void)
52 static service_user *nip = NULL;
54 __nss_database_lookup("group_nonlocal", NULL, "", &nip);
61 check_nonlocal_gid(const char *user, gid_t gid, int *errnop)
63 enum nss_status status = NSS_STATUS_SUCCESS;
65 struct group *gbufp = &gbuf;
67 int old_errno = errno;
68 int buflen = MAGIC_LOCAL_GR_BUFLEN;
69 char *buf = malloc(buflen);
73 return NSS_STATUS_TRYAGAIN;
76 ret = getgrgid_r(gid, gbufp, buf, buflen, &gbufp);
79 status = NSS_STATUS_TRYAGAIN;
80 } else if (gbufp != NULL) {
81 syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
82 status = NSS_STATUS_NOTFOUND;
90 get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen, int *errnop)
92 enum nss_status status = NSS_STATUS_NOTFOUND;
94 struct group *gbufp = &gbuf;
96 int old_errno = errno;
97 int len = MAGIC_LOCAL_GR_BUFLEN;
98 char *buf = malloc(len);
102 return NSS_STATUS_TRYAGAIN;
105 ret = getgrnam_r(name, gbufp, buf, len, &gbufp);
108 status = NSS_STATUS_TRYAGAIN;
109 } else if (gbufp != NULL) {
110 status = NSS_STATUS_SUCCESS;
111 grp->gr_name = strncpy(buffer, gbufp->gr_name, buflen);
112 buffer = buffer + strlen(grp->gr_name);
113 buflen = buflen - strlen(grp->gr_name);
114 grp->gr_passwd = strncpy(buffer, gbufp->gr_passwd, buflen);
115 buffer = buffer + strlen(grp->gr_passwd);
116 buflen = buflen - strlen(grp->gr_passwd);
117 grp->gr_gid = gbufp->gr_gid;
118 if (buflen < sizeof(void *)) {
120 status = NSS_STATUS_TRYAGAIN;
123 grp->gr_mem = memset(buffer, 0, sizeof(void *));
131 static service_user *grent_nip = NULL;
132 static void *grent_fct_start;
134 enum nss_status (*l)(struct group *grp, char *buffer, size_t buflen,
138 static const char *grent_fct_name = "getgrent_r";
141 _nss_nonlocal_setgrent(int stayopen)
143 static const char *fct_name = "setgrent";
144 static void *fct_start = NULL;
145 enum nss_status status;
148 enum nss_status (*l)(int stayopen);
152 nip = nss_group_nonlocal_database();
154 return NSS_STATUS_UNAVAIL;
155 if (fct_start == NULL)
156 fct_start = __nss_lookup_function(nip, fct_name);
160 status = NSS_STATUS_UNAVAIL;
162 status = DL_CALL_FCT(fct.l, (stayopen));
163 } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
164 if (status != NSS_STATUS_SUCCESS)
168 if (grent_fct_start == NULL)
169 grent_fct_start = __nss_lookup_function(nip, grent_fct_name);
170 grent_fct.ptr = grent_fct_start;
171 return NSS_STATUS_SUCCESS;
175 _nss_nonlocal_endgrent(void)
177 static const char *fct_name = "endgrent";
178 static void *fct_start = NULL;
179 enum nss_status status;
182 enum nss_status (*l)(void);
188 nip = nss_group_nonlocal_database();
190 return NSS_STATUS_UNAVAIL;
191 if (fct_start == NULL)
192 fct_start = __nss_lookup_function(nip, fct_name);
196 status = NSS_STATUS_UNAVAIL;
198 status = DL_CALL_FCT(fct.l, ());
199 } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
204 _nss_nonlocal_getgrent_r(struct group *grp, char *buffer, size_t buflen,
207 enum nss_status status;
208 if (grent_nip == NULL) {
209 status = _nss_nonlocal_setgrent(0);
210 if (status != NSS_STATUS_SUCCESS)
214 if (grent_fct.ptr == NULL)
215 status = NSS_STATUS_UNAVAIL;
219 status = DL_CALL_FCT(grent_fct.l, (grp, buffer, buflen, errnop));
220 while (status == NSS_STATUS_SUCCESS &&
221 check_nonlocal_gid("(unknown)", grp->gr_gid, &nonlocal_errno) != NSS_STATUS_SUCCESS);
223 if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
226 if (status == NSS_STATUS_SUCCESS)
227 return NSS_STATUS_SUCCESS;
228 } while (__nss_next(&grent_nip, grent_fct_name, &grent_fct.ptr, status, 0) == 0);
231 return NSS_STATUS_NOTFOUND;
236 _nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
237 char *buffer, size_t buflen, int *errnop)
239 static const char *fct_name = "getgrnam_r";
240 static void *fct_start = NULL;
241 enum nss_status status;
244 enum nss_status (*l)(const char *name, struct group *grp,
245 char *buffer, size_t buflen, int *errnop);
249 if (buflen == MAGIC_LOCAL_GR_BUFLEN)
250 return NSS_STATUS_UNAVAIL;
252 nip = nss_group_nonlocal_database();
254 return NSS_STATUS_UNAVAIL;
255 if (fct_start == NULL)
256 fct_start = __nss_lookup_function(nip, fct_name);
260 status = NSS_STATUS_UNAVAIL;
262 status = DL_CALL_FCT(fct.l, (name, grp, buffer, buflen, errnop));
263 if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
265 } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
266 if (status != NSS_STATUS_SUCCESS)
269 return check_nonlocal_gid(name, grp->gr_gid, errnop);
273 _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
274 char *buffer, size_t buflen, int *errnop)
276 static const char *fct_name = "getgrgid_r";
277 static void *fct_start = NULL;
278 enum nss_status status;
281 enum nss_status (*l)(gid_t gid, struct group *grp,
282 char *buffer, size_t buflen, int *errnop);
286 if (buflen == MAGIC_LOCAL_GR_BUFLEN)
287 return NSS_STATUS_UNAVAIL;
289 nip = nss_group_nonlocal_database();
291 return NSS_STATUS_UNAVAIL;
292 if (fct_start == NULL)
293 fct_start = __nss_lookup_function(nip, fct_name);
297 status = NSS_STATUS_UNAVAIL;
299 status = DL_CALL_FCT(fct.l, (gid, grp, buffer, buflen, errnop));
300 if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
302 } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
303 if (status != NSS_STATUS_SUCCESS)
306 return check_nonlocal_gid(grp->gr_name, grp->gr_gid, errnop);
310 _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
311 long int *size, gid_t **groupsp, long int limit,
314 static const char *fct_name = "initgroups_dyn";
315 static void *fct_start = NULL;
316 enum nss_status status;
319 enum nss_status (*l)(const char *user, gid_t group, long int *start,
320 long int *size, gid_t **groupsp, long int limit,
324 int in = *start, out = *start, i;
325 gid_t local_users_gid;
328 // Check that the user is a nonlocal user before adding any groups
329 status = check_nonlocal_user(user, errnop);
330 if (status == NSS_STATUS_NOTFOUND) {
333 else if (status != NSS_STATUS_SUCCESS) {
337 int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
338 char *buffer = malloc(buflen);
339 if (buffer == NULL) {
341 return NSS_STATUS_TRYAGAIN;
343 struct group local_users_group;
344 status = get_local_group(MAGIC_LOCAL_GROUPNAME,
345 &local_users_group, buffer, buflen, errnop);
347 if (status == NSS_STATUS_NOTFOUND) {
348 syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
349 MAGIC_LOCAL_GROUPNAME);
352 else if (status == NSS_STATUS_SUCCESS) {
354 // add the (local) user to the magic local users group, and finish
355 (*groupsp)[out++] = local_users_group.gr_gid;
356 syslog(LOG_DEBUG, "nss_nonlocal: Added %s to special group %s",
357 user, MAGIC_LOCAL_GROUPNAME);
359 return NSS_STATUS_SUCCESS;
362 local_users_gid = local_users_group.gr_gid;
369 nip = nss_group_nonlocal_database();
371 return NSS_STATUS_UNAVAIL;
372 if (fct_start == NULL)
373 fct_start = __nss_lookup_function(nip, fct_name);
378 status = NSS_STATUS_UNAVAIL;
380 status = DL_CALL_FCT(fct.l, (user, group, start, size, groupsp, limit, errnop));
381 if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
383 } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
384 if (status != NSS_STATUS_SUCCESS)
387 for (; in < *start; ++in) {
388 int nonlocal_errno = *errnop;
390 for (i = 0; i < out; ++i)
391 if ((*groupsp)[i] == (*groupsp)[in])
396 status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
397 if (status == NSS_STATUS_SUCCESS) {
398 // Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons.
399 if ((*groupsp)[in] == local_users_gid) {
400 syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s",
401 user, MAGIC_LOCAL_GROUPNAME);
404 (*groupsp)[out++] = (*groupsp)[in];
406 } else if (status != NSS_STATUS_NOTFOUND) {
408 *errnop = nonlocal_errno;
413 // add the (nonlocal) user to the magic nonlocal users group
414 buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
415 buffer = malloc(buflen);
416 if (buffer == NULL) {
418 return NSS_STATUS_TRYAGAIN;
420 struct group nonlocal_users_group;
421 status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
422 &nonlocal_users_group, buffer, buflen, errnop);
423 if (status == NSS_STATUS_NOTFOUND) {
424 syslog(LOG_WARNING, "nss_nonlocal: (local) group %s does not exist!",
425 MAGIC_NONLOCAL_GROUPNAME);
427 else if (status == NSS_STATUS_SUCCESS) {
428 (*groupsp)[out++] = nonlocal_users_group.gr_gid;
429 syslog(LOG_DEBUG, "nss_nonlocal: Added %s to special group %s",
430 user, MAGIC_NONLOCAL_GROUPNAME);
435 return NSS_STATUS_SUCCESS;