xref: /titanic_41/usr/src/lib/nsswitch/compat/common/getgrent.c (revision 45916cd2fec6e79bca5dee0421bd39e3c2910d1e)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  *	getgrent.c
24  *
25  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
26  * Use is subject to license terms.
27  *
28  * lib/nsswitch/compat/getgrent.c -- name-service-switch backend for getgrnam()
29  *   et al that does 4.x compatibility.  It looks in /etc/group; if it finds
30  *   group entries there that begin with "+" or "-", it consults other
31  *   services.  By default it uses NIS (YP), but the user can override this
32  *   with a "group_compat" entry in /etc/nsswitch.conf, e.g.
33  *			group_compat: nisplus
34  *
35  * This code tries to produce the same results as the 4.x code, even when
36  *   the latter seems ill thought-out.  Bug-compatible, in other words.
37  *   Though we do try to be more reasonable about the format of "+" and "-"
38  *   entries here, i.e. you don't have to pad them with spurious colons and
39  *   bogus uid/gid values.
40  *
41  * Caveats:
42  *    -	More than one source may be specified, with the usual switch semantics,
43  *	but having multiple sources here is definitely odd.
44  *    -	People who recursively specify "compat" deserve what they get.
45  */
46 
47 #pragma ident	"%Z%%M%	%I%	%E% SMI"
48 
49 #include <grp.h>
50 #include <stdlib.h>
51 #include <unistd.h>		/* for GF_PATH */
52 #include <strings.h>
53 #include "compat_common.h"
54 
55 static DEFINE_NSS_DB_ROOT(db_root);
56 
57 static void
58 _nss_initf_group_compat(p)
59 	nss_db_params_t	*p;
60 {
61 	p->name		  = NSS_DBNAM_GROUP;
62 	p->config_name	  = NSS_DBNAM_GROUP_COMPAT;
63 	p->default_config = NSS_DEFCONF_GROUP_COMPAT;
64 }
65 
66 static const char *
67 get_grname(argp)
68 	nss_XbyY_args_t		*argp;
69 {
70 	struct group		*g = (struct group *)argp->returnval;
71 
72 	return (g->gr_name);
73 }
74 
75 static int
76 check_grname(argp)
77 	nss_XbyY_args_t		*argp;
78 {
79 	struct group		*g = (struct group *)argp->returnval;
80 
81 	return (strcmp(g->gr_name, argp->key.name) == 0);
82 }
83 
84 static nss_status_t
85 getbyname(be, a)
86 	compat_backend_ptr_t	be;
87 	void			*a;
88 {
89 	nss_XbyY_args_t		*argp = (nss_XbyY_args_t *)a;
90 
91 	return (_nss_compat_XY_all(be, argp, check_grname,
92 				NSS_DBOP_GROUP_BYNAME));
93 }
94 
95 static int
96 check_grgid(argp)
97 	nss_XbyY_args_t		*argp;
98 {
99 	struct group		*g = (struct group *)argp->returnval;
100 
101 	return (g->gr_gid == argp->key.gid);
102 }
103 
104 static nss_status_t
105 getbygid(be, a)
106 	compat_backend_ptr_t	be;
107 	void			*a;
108 {
109 	nss_XbyY_args_t		*argp = (nss_XbyY_args_t *)a;
110 
111 	return (_nss_compat_XY_all(be, argp, check_grgid,
112 				NSS_DBOP_GROUP_BYGID));
113 }
114 
115 static nss_status_t
116 getbymember(be, a)
117 	compat_backend_ptr_t	be;
118 	void			*a;
119 {
120 	struct nss_groupsbymem	*argp = (struct nss_groupsbymem *)a;
121 	int			numgids = argp->numgids;
122 	int			maxgids = argp->maxgids;
123 	gid_t			*gid_array = argp->gid_array;
124 	struct nss_XbyY_args	grargs;
125 	struct group		*g;
126 	nss_XbyY_buf_t	*gb = NULL, *b = NULL;
127 
128 	/*
129 	 * Generic implementation:  enumerate using getent(), then check each
130 	 *   group returned by getent() to see whether it contains the user.
131 	 *   There are much faster ways, but at least this one gets the right
132 	 *   answer.
133 	 */
134 	if (numgids >= maxgids) {
135 		/* full gid_array;  nobody should have bothered to call us */
136 		return (NSS_SUCCESS);
137 	}
138 
139 	b = NSS_XbyY_ALLOC(&gb, sizeof (struct group), NSS_BUFLEN_GROUP);
140 	if (b == 0)
141 		return (NSS_UNAVAIL);
142 
143 	NSS_XbyY_INIT(&grargs, gb->result, gb->buffer, gb->buflen,
144 		argp->str2ent);
145 	g = (struct group *)gb->result;
146 
147 	(void) _nss_compat_setent(be, 0);
148 	while (_nss_compat_getent(be, &grargs) == NSS_SUCCESS) {
149 		char		**mem;
150 
151 		if (grargs.returnval == 0) {
152 			continue;
153 		}
154 		for (mem = g->gr_mem;  *mem != 0;  mem++) {
155 			if (strcmp(*mem, argp->username) == 0) {
156 				int	gid = g->gr_gid;
157 				int	i;
158 				for (i = 0;  i < numgids;  i++) {
159 					if (gid == gid_array[i]) {
160 						break;
161 					}
162 				}
163 				if (i == numgids) {
164 					gid_array[numgids++] = gid;
165 					argp->numgids = numgids;
166 					if (numgids >= maxgids) {
167 						/* filled the gid_array */
168 						(void) _nss_compat_endent(be,
169 								0);
170 						NSS_XbyY_FREE(&gb);
171 						return (NSS_SUCCESS);
172 					}
173 					/* Done with this group, try next */
174 					break;
175 				}
176 			}
177 		}
178 	}
179 	(void) _nss_compat_endent(be, 0);
180 	NSS_XbyY_FREE(&gb);
181 	return (NSS_NOTFOUND);	/* Really means "gid_array not full yet" */
182 }
183 
184 /*ARGSUSED*/
185 static int
186 merge_grents(be, argp, fields)
187 	compat_backend_ptr_t	be;
188 	nss_XbyY_args_t		*argp;
189 	const char		**fields;
190 {
191 	struct group		*g	= (struct group *)argp->buf.result;
192 	char			*buf;
193 	char			*s;
194 	int			parsestat;
195 
196 	/*
197 	 * We're allowed to override the passwd (has anyone ever actually used
198 	 *   the passwd in a group entry?) and the membership list, but not
199 	 *   the groupname or the gid.
200 	 * That's what the SunOS 4.x code did;  who are we to question it...
201 	 *
202 	 * Efficiency is heartlessly abandoned in the quest for simplicity.
203 	 */
204 	if (fields[1] == 0 && fields[3] == 0) {
205 		/* No legal overrides, leave *argp unscathed */
206 		return (NSS_STR_PARSE_SUCCESS);
207 	}
208 	if ((buf = malloc(NSS_LINELEN_GROUP)) == 0) {
209 		return (NSS_STR_PARSE_PARSE);
210 		/* Really "out of memory", but PARSE_PARSE will have to do */
211 	}
212 	s = buf;
213 	(void) snprintf(s, NSS_LINELEN_GROUP, "%s:%s:%d:",
214 		g->gr_name,
215 		fields[1] != 0 ? fields[1] : g->gr_passwd,
216 		g->gr_gid);
217 	s += strlen(s);
218 	if (fields[3] != 0) {
219 		strcpy(s, fields[3]);
220 		s += strlen(s);
221 	} else {
222 		char	**memp;
223 
224 		for (memp = g->gr_mem;  *memp != 0;  memp++) {
225 			size_t	len = strlen(*memp);
226 			if (s + len + 1 <= buf + NSS_LINELEN_GROUP) {
227 				if (memp != g->gr_mem) {
228 					*s++ = ',';
229 				}
230 				(void) memcpy(s, *memp, len);
231 				s += len;
232 			} else {
233 				free(buf);
234 				return (NSS_STR_PARSE_ERANGE);
235 			}
236 		}
237 	}
238 	parsestat = (*argp->str2ent)(buf, s - buf,
239 				    argp->buf.result,
240 				    argp->buf.buffer,
241 				    argp->buf.buflen);
242 	free(buf);
243 	return (parsestat);
244 }
245 
246 static compat_backend_op_t group_ops[] = {
247 	_nss_compat_destr,
248 	_nss_compat_endent,
249 	_nss_compat_setent,
250 	_nss_compat_getent,
251 	getbyname,
252 	getbygid,
253 	getbymember
254 };
255 
256 /*ARGSUSED*/
257 nss_backend_t *
258 _nss_compat_group_constr(dummy1, dummy2, dummy3)
259 	const char	*dummy1, *dummy2, *dummy3;
260 {
261 	return (_nss_compat_constr(group_ops,
262 				sizeof (group_ops) / sizeof (group_ops[0]),
263 				GF_PATH,
264 				NSS_LINELEN_GROUP,
265 				&db_root,
266 				_nss_initf_group_compat,
267 				0,
268 				get_grname,
269 				merge_grents));
270 }
271