xref: /illumos-gate/usr/src/lib/nsswitch/ldap/common/getgrent.c (revision 5328fc53d11d7151861fa272e4fb0248b8f0e145)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  *
25  * Copyright 2017 Nexenta Systems, Inc.  All rights reserved.
26  */
27 
28 #include <grp.h>
29 #include "ldap_common.h"
30 #include <string.h>
31 
32 /* String which may need to be removed from beginning of group password */
33 #define	_CRYPT		"{CRYPT}"
34 #define	_NO_PASSWD_VAL	""
35 
36 /* Group attributes filters */
37 #define	_G_NAME		"cn"
38 #define	_G_GID		"gidnumber"
39 #define	_G_PASSWD	"userpassword"
40 #define	_G_MEMUID	"memberuid"
41 #define	_G_MEM_DN	"member"	/* DN */
42 
43 #define	_F_GETGRNAM	"(&(objectClass=posixGroup)(cn=%s))"
44 #define	_F_GETGRNAM_SSD	"(&(%%s)(cn=%s))"
45 #define	_F_GETGRGID	"(&(objectClass=posixGroup)(gidNumber=%u))"
46 #define	_F_GETGRGID_SSD	"(&(%%s)(gidNumber=%u))"
47 
48 /*
49  * When searching for groups in which a specified user is a member,
50  * there are a few different membership schema that might be in use.
51  * We'll use a filter that should work with an of the common ones:
52  * "memberUid=NAME", or "member=DN" (try uniquemember too?)
53  * The first parameter in the filter string is replaced by username,
54  * and the remaining ones by the full DN.
55  */
56 #define	_F_GETGRMEM "(&(objectClass=posixGroup)" \
57 	"(|(memberUid=%s)(member=%s)))"
58 #define	_F_GETGRMEM_SSD	"(&(%%s)" \
59 	"(|(memberUid=%s)(member=%s)))"
60 
61 static const char *gr_attrs[] = {
62 	_G_NAME,
63 	_G_GID,
64 	_G_PASSWD,
65 	_G_MEMUID,
66 	_G_MEM_DN,
67 	(char *)NULL
68 };
69 
70 static int
71 getmembers_UID(char **bufpp, int *lenp, ns_ldap_attr_t *members);
72 static int
73 getmembers_DN(char **bufpp, int *lenp, ns_ldap_attr_t *members);
74 
75 
76 /*
77  * _nss_ldap_group2str is the data marshaling method for the group getXbyY
78  * (e.g., getgrnam(), getgrgid(), getgrent()) backend processes. This method
79  * is called after a successful ldap search has been performed. This method
80  * will parse the ldap search values into the file format.
81  * e.g.
82  *
83  * adm::4:root,adm,daemon
84  *
85  */
86 
87 static int
88 _nss_ldap_group2str(ldap_backend_ptr be, nss_XbyY_args_t *argp)
89 {
90 	int		i;
91 	int		nss_result;
92 	int		buflen = 0, len;
93 	char		*buffer = NULL;
94 	ns_ldap_result_t	*result = be->result;
95 	char		**gname, **passwd, **gid, *password, *end;
96 	char		gid_nobody[NOBODY_STR_LEN];
97 	char		*gid_nobody_v[1];
98 	ns_ldap_attr_t	*members;
99 
100 	(void) snprintf(gid_nobody, sizeof (gid_nobody), "%u", GID_NOBODY);
101 	gid_nobody_v[0] = gid_nobody;
102 
103 	if (result == NULL)
104 		return (NSS_STR_PARSE_PARSE);
105 	buflen = argp->buf.buflen;
106 
107 	if (argp->buf.result != NULL) {
108 		if ((be->buffer = calloc(1, buflen)) == NULL) {
109 			nss_result = NSS_STR_PARSE_PARSE;
110 			goto result_grp2str;
111 		}
112 		buffer = be->buffer;
113 	} else
114 		buffer = argp->buf.buffer;
115 
116 	nss_result = NSS_STR_PARSE_SUCCESS;
117 	(void) memset(buffer, 0, buflen);
118 
119 	gname = __ns_ldap_getAttr(result->entry, _G_NAME);
120 	if (gname == NULL || gname[0] == NULL || (strlen(gname[0]) < 1)) {
121 		nss_result = NSS_STR_PARSE_PARSE;
122 		goto result_grp2str;
123 	}
124 	passwd = __ns_ldap_getAttr(result->entry, _G_PASSWD);
125 	if (passwd == NULL || passwd[0] == NULL || (strlen(passwd[0]) == 0)) {
126 		/* group password could be NULL, replace it with "" */
127 		password = _NO_PASSWD_VAL;
128 	} else {
129 		/*
130 		 * Preen "{crypt}" if necessary.
131 		 * If the password does not include the {crypt} prefix
132 		 * then the password may be plain text.  And thus
133 		 * perhaps crypt(3c) should be used to encrypt it.
134 		 * Currently the password is copied verbatim.
135 		 */
136 		if (strncasecmp(passwd[0], _CRYPT, strlen(_CRYPT)) == 0)
137 			password = passwd[0] + strlen(_CRYPT);
138 		else
139 			password = passwd[0];
140 	}
141 	gid = __ns_ldap_getAttr(result->entry, _G_GID);
142 	if (gid == NULL || gid[0] == NULL || (strlen(gid[0]) < 1)) {
143 		nss_result = NSS_STR_PARSE_PARSE;
144 		goto result_grp2str;
145 	}
146 	/* Validate GID */
147 	if (strtoul(gid[0], &end, 10) > MAXUID)
148 		gid = gid_nobody_v;
149 	len = snprintf(buffer, buflen, "%s:%s:%s:", gname[0], password, gid[0]);
150 	TEST_AND_ADJUST(len, buffer, buflen, result_grp2str);
151 
152 	members = __ns_ldap_getAttrStruct(result->entry, _G_MEMUID);
153 	if (members != NULL && members->attrvalue != NULL) {
154 		nss_result = getmembers_UID(&buffer, &buflen, members);
155 		if (nss_result != 0)
156 			goto result_grp2str;
157 	}
158 
159 	members = __ns_ldap_getAttrStruct(result->entry, _G_MEM_DN);
160 	if (members != NULL && members->attrvalue != NULL) {
161 		nss_result = getmembers_DN(&buffer, &buflen, members);
162 		if (nss_result != 0)
163 			goto result_grp2str;
164 	}
165 
166 	/* The front end marshaller doesn't need the trailing nulls */
167 	if (argp->buf.result != NULL)
168 		be->buflen = strlen(be->buffer);
169 result_grp2str:
170 	(void) __ns_ldap_freeResult(&be->result);
171 	return (nss_result);
172 }
173 
174 /*
175  * Process the list values from the "memberUid" attribute of the
176  * current group.  Note that this list is often empty, and we
177  * get the real list of members via getmember_DN (see below).
178  */
179 static int
180 getmembers_UID(char **bufpp, int *lenp, ns_ldap_attr_t *members)
181 {
182 	char	*member_str, *strtok_state;
183 	char	*buffer;
184 	int	buflen;
185 	int	i, len;
186 	int	nss_result = 0;
187 	int	firsttime;
188 
189 	buffer = *bufpp;
190 	buflen = *lenp;
191 	firsttime = (buffer[-1] == ':');
192 
193 	for (i = 0; i < members->value_count; i++) {
194 		member_str = members->attrvalue[i];
195 		if (member_str == NULL)
196 			goto out;
197 
198 #ifdef DEBUG
199 		(void) fprintf(stdout, "getmembers_UID: uid=<%s>\n",
200 		    member_str);
201 #endif
202 		/*
203 		 * If not a valid Unix user name, or
204 		 * not valid in ldap, just skip.
205 		 */
206 		if (member_str[0] == '\0' ||
207 		    strpbrk(member_str, " ,:=") != NULL)
208 			continue;
209 
210 		if (firsttime) {
211 			len = snprintf(buffer, buflen, "%s", member_str);
212 			firsttime = 0;
213 		} else {
214 			len = snprintf(buffer, buflen, ",%s", member_str);
215 		}
216 		TEST_AND_ADJUST(len, buffer, buflen, out);
217 	}
218 
219 out:
220 	*bufpp = buffer;
221 	*lenp = buflen;
222 	return (nss_result);
223 }
224 
225 /*
226  * Process the list values from the "member" attribute of the
227  * current group.  Note that this list is ONLY one that can be
228  * assumed to be non-empty.  The problem here is that this list
229  * contains the list of members as "distinguished names" (DN),
230  * and we want the Unix names (known here as "uid").  We must
231  * lookup the "uid" for each DN in the member list.  Example:
232  * CN=Doe\, John,OU=Users,DC=contoso,DC=com => john.doe
233  */
234 static int
235 getmembers_DN(char **bufpp, int *lenp, ns_ldap_attr_t *members)
236 {
237 	ns_ldap_error_t *error = NULL;
238 	char	*member_dn, *member_uid;
239 	char	*buffer;
240 	int	buflen;
241 	int	i, len;
242 	int	nss_result = 0;
243 	int	firsttime;
244 
245 	buffer = *bufpp;
246 	buflen = *lenp;
247 	firsttime = (buffer[-1] == ':');
248 
249 	for (i = 0; i < members->value_count; i++) {
250 		member_dn = members->attrvalue[i];
251 		if (member_dn == NULL)
252 			goto out;
253 
254 		/*
255 		 * The attribute name was "member", so these should be
256 		 * full distinguished names (DNs).  We need to loookup
257 		 * the Unix UID (name) for each.
258 		 */
259 #ifdef DEBUG
260 		(void) fprintf(stdout, "getmembers_DN: dn=%s\n",
261 		    member_dn);
262 #endif
263 		if (member_dn[0] == '\0')
264 			continue;
265 
266 		nss_result = __ns_ldap_dn2uid(member_dn,
267 		    &member_uid, NULL, &error);
268 		if (nss_result != NS_LDAP_SUCCESS) {
269 			(void) __ns_ldap_freeError(&error);
270 			error = NULL;
271 			continue;
272 		}
273 #ifdef DEBUG
274 		(void) fprintf(stdout, "getmembers_DN: uid=<%s>\n",
275 		    member_uid);
276 #endif
277 		/* Skip invalid names. */
278 		if (member_uid[0] == '\0' ||
279 		    strpbrk(member_uid, " ,:=") != NULL) {
280 			free(member_uid);
281 			continue;
282 		}
283 
284 		if (firsttime) {
285 			len = snprintf(buffer, buflen, "%s", member_uid);
286 			firsttime = 0;
287 		} else {
288 			len = snprintf(buffer, buflen, ",%s", member_uid);
289 		}
290 		free(member_uid);
291 		TEST_AND_ADJUST(len, buffer, buflen, out);
292 	}
293 
294 out:
295 	*bufpp = buffer;
296 	*lenp = buflen;
297 	return (nss_result);
298 }
299 
300 /*
301  * getbynam gets a group entry by name. This function constructs an ldap
302  * search filter using the name invocation parameter and the getgrnam search
303  * filter defined. Once the filter is constructed, we searche for a matching
304  * entry and marshal the data results into struct group for the frontend
305  * process. The function _nss_ldap_group2ent performs the data marshaling.
306  */
307 
308 static nss_status_t
309 getbynam(ldap_backend_ptr be, void *a)
310 {
311 	nss_XbyY_args_t	*argp = (nss_XbyY_args_t *)a;
312 	char		searchfilter[SEARCHFILTERLEN];
313 	char		userdata[SEARCHFILTERLEN];
314 	char		groupname[SEARCHFILTERLEN];
315 	int		ret;
316 
317 	if (_ldap_filter_name(groupname, argp->key.name, sizeof (groupname)) !=
318 	    0)
319 		return ((nss_status_t)NSS_NOTFOUND);
320 
321 	ret = snprintf(searchfilter, sizeof (searchfilter),
322 	    _F_GETGRNAM, groupname);
323 	if (ret >= sizeof (searchfilter) || ret < 0)
324 		return ((nss_status_t)NSS_NOTFOUND);
325 
326 	ret = snprintf(userdata, sizeof (userdata), _F_GETGRNAM_SSD, groupname);
327 	if (ret >= sizeof (userdata) || ret < 0)
328 		return ((nss_status_t)NSS_NOTFOUND);
329 
330 	return ((nss_status_t)_nss_ldap_lookup(be, argp,
331 	    _GROUP, searchfilter, NULL, _merge_SSD_filter, userdata));
332 }
333 
334 
335 /*
336  * getbygid gets a group entry by number. This function constructs an ldap
337  * search filter using the name invocation parameter and the getgrgid search
338  * filter defined. Once the filter is constructed, we searche for a matching
339  * entry and marshal the data results into struct group for the frontend
340  * process. The function _nss_ldap_group2ent performs the data marshaling.
341  */
342 
343 static nss_status_t
344 getbygid(ldap_backend_ptr be, void *a)
345 {
346 	nss_XbyY_args_t	*argp = (nss_XbyY_args_t *)a;
347 	char searchfilter[SEARCHFILTERLEN];
348 	char userdata[SEARCHFILTERLEN];
349 	int ret;
350 
351 	if (argp->key.uid > MAXUID)
352 		return ((nss_status_t)NSS_NOTFOUND);
353 
354 	ret = snprintf(searchfilter, sizeof (searchfilter),
355 	    _F_GETGRGID, argp->key.uid);
356 	if (ret >= sizeof (searchfilter) || ret < 0)
357 		return ((nss_status_t)NSS_NOTFOUND);
358 
359 	ret = snprintf(userdata, sizeof (userdata),
360 	    _F_GETGRGID_SSD, argp->key.uid);
361 	if (ret >= sizeof (userdata) || ret < 0)
362 		return ((nss_status_t)NSS_NOTFOUND);
363 
364 	return ((nss_status_t)_nss_ldap_lookup(be, argp,
365 	    _GROUP, searchfilter, NULL, _merge_SSD_filter, userdata));
366 
367 }
368 
369 
370 /*
371  * Use a custom attributes list for getbymember, because the LDAP
372  * query for this requests a list of groups, and the result can be
373  * very large if it includes the list of members with each group.
374  * We don't need or want the list of members in this case.
375  */
376 static const char *grbymem_attrs[] = {
377 	_G_NAME,	/* cn */
378 	_G_GID,		/* gidnumber */
379 	(char *)NULL
380 };
381 
382 /*
383  * getbymember returns all groups a user is defined in. This function
384  * uses different architectural procedures than the other group backend
385  * system calls because it's a private interface. This function constructs
386  * an ldap search filter using the name invocation parameter. Once the
387  * filter is constructed, we search for all matching groups counting
388  * and storing each group name, gid, etc. Data marshaling is used for
389  * group processing. The function _nss_ldap_group2ent() performs the
390  * data marshaling.
391  *
392  * (const char *)argp->username;	(size_t)strlen(argp->username);
393  * (gid_t)argp->gid_array;		(int)argp->maxgids;
394  * (int)argp->numgids;
395  */
396 
397 static nss_status_t
398 getbymember(ldap_backend_ptr be, void *a)
399 {
400 	ns_ldap_error_t		*error = NULL;
401 	int			i, j, k;
402 	int			gcnt = (int)0;
403 	char			**groupvalue;
404 	nss_status_t		lstat;
405 	struct nss_groupsbymem	*argp = (struct nss_groupsbymem *)a;
406 	char			searchfilter[SEARCHFILTERLEN];
407 	char			userdata[SEARCHFILTERLEN];
408 	char			name[SEARCHFILTERLEN];
409 	char			escdn[SEARCHFILTERLEN];
410 	ns_ldap_result_t	*result;
411 	ns_ldap_entry_t		*curEntry;
412 	char			*dn;
413 	gid_t			gid;
414 	int			ret1, ret2;
415 
416 	if (strcmp(argp->username, "") == 0 ||
417 	    strcmp(argp->username, "root") == 0)
418 		return ((nss_status_t)NSS_NOTFOUND);
419 
420 	if (_ldap_filter_name(name, argp->username, sizeof (name)) != 0)
421 		return ((nss_status_t)NSS_NOTFOUND);
422 
423 	/*
424 	 * Look up the user DN in ldap. If it's not found, search solely by
425 	 * username.
426 	 */
427 	lstat = __ns_ldap_uid2dn(name, &dn, NULL, &error);
428 	if (lstat != (nss_status_t)NS_LDAP_SUCCESS) {
429 		/* Can't get DN.  Use bare name */
430 		(void) __ns_ldap_freeError(&error);
431 		dn = name;
432 	}
433 	/* Note: must free dn if != name */
434 
435 	/*
436 	 * Compose filter patterns
437 	 */
438 	ret1 = snprintf(searchfilter, sizeof (searchfilter),
439 	    _F_GETGRMEM, name, dn);
440 	ret2 = snprintf(userdata, sizeof (userdata),
441 	    _F_GETGRMEM_SSD, name, dn);
442 	if (dn != name)
443 		free(dn);
444 	if (ret1 >= sizeof (searchfilter) || ret1 < 0)
445 		return ((nss_status_t)NSS_NOTFOUND);
446 	if (ret2 >= sizeof (userdata) || ret2 < 0)
447 		return ((nss_status_t)NSS_NOTFOUND);
448 
449 	/*
450 	 * Query for groups matching the filter.
451 	 */
452 	lstat = (nss_status_t)_nss_ldap_nocb_lookup(be, NULL,
453 	    _GROUP, searchfilter, grbymem_attrs,
454 	    _merge_SSD_filter, userdata);
455 	if (lstat != (nss_status_t)NS_LDAP_SUCCESS)
456 		return ((nss_status_t)lstat);
457 	if (be->result == NULL)
458 		return (NSS_NOTFOUND);
459 
460 	/*
461 	 * Walk the query result, collecting GIDs.
462 	 */
463 	result = (ns_ldap_result_t *)be->result;
464 	curEntry = (ns_ldap_entry_t *)result->entry;
465 	gcnt = (int)argp->numgids;
466 	for (i = 0; i < result->entries_count; i++) {
467 
468 		/*
469 		 * Does this group have a gidNumber attr?
470 		 */
471 		groupvalue = __ns_ldap_getAttr(curEntry, _G_GID);
472 		if (groupvalue == NULL || groupvalue[0] == NULL) {
473 			/* Drop this group from the list */
474 			goto next_group;
475 		}
476 
477 		/*
478 		 * Convert it to a numeric GID
479 		 */
480 		errno = 0;
481 		gid = (gid_t)strtol(groupvalue[0], (char **)NULL, 10);
482 		if (errno != 0)
483 			goto next_group;
484 
485 		/*
486 		 * If we don't already have this GID, add it.
487 		 */
488 		if (argp->numgids < argp->maxgids) {
489 			for (k = 0; k < argp->numgids; k++) {
490 				if (argp->gid_array[k] == gid) {
491 					/* already have it */
492 					goto next_group;
493 				}
494 			}
495 			argp->gid_array[argp->numgids++] = gid;
496 		}
497 
498 	next_group:
499 		curEntry = curEntry->next;
500 	}
501 
502 	(void) __ns_ldap_freeResult((ns_ldap_result_t **)&be->result);
503 	if (gcnt == argp->numgids)
504 		return ((nss_status_t)NSS_NOTFOUND);
505 
506 	/*
507 	 * Return NSS_SUCCESS only if array is full.
508 	 * Explained in <nss_dbdefs.h>.
509 	 */
510 	return ((nss_status_t)((argp->numgids == argp->maxgids)
511 	    ? NSS_SUCCESS
512 	    : NSS_NOTFOUND));
513 }
514 
515 static ldap_backend_op_t gr_ops[] = {
516 	_nss_ldap_destr,
517 	_nss_ldap_endent,
518 	_nss_ldap_setent,
519 	_nss_ldap_getent,
520 	getbynam,
521 	getbygid,
522 	getbymember
523 };
524 
525 
526 /*ARGSUSED0*/
527 nss_backend_t *
528 _nss_ldap_group_constr(const char *dummy1, const char *dummy2,
529     const char *dummy3)
530 {
531 
532 	return ((nss_backend_t *)_nss_ldap_constr(gr_ops,
533 	    sizeof (gr_ops)/sizeof (gr_ops[0]), _GROUP, gr_attrs,
534 	    _nss_ldap_group2str));
535 }
536