xref: /illumos-gate/usr/src/lib/nsswitch/nis/common/getgrent.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
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  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * nis/getgrent.c -- "nis" backend for nsswitch "group" database
29  */
30 
31 #pragma ident	"%Z%%M%	%I%	%E% SMI"
32 
33 #include <grp.h>
34 #include <pwd.h>
35 #include "nis_common.h"
36 #include <ctype.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <rpc/auth.h>	/* for MAXNETNAMELEN */
40 
41 static nss_status_t netid_lookup(struct nss_groupsbymem *argp);
42 
43 static nss_status_t
44 getbyname(be, a)
45 	nis_backend_ptr_t	be;
46 	void			*a;
47 {
48 	nss_XbyY_args_t		*argp = (nss_XbyY_args_t *)a;
49 
50 	return (_nss_nis_lookup(be, argp, 0,
51 				"group.byname", argp->key.name, 0));
52 }
53 
54 static nss_status_t
55 getbygid(be, a)
56 	nis_backend_ptr_t	be;
57 	void			*a;
58 {
59 	nss_XbyY_args_t		*argp = (nss_XbyY_args_t *)a;
60 	char			gidstr[12];	/* More than enough */
61 
62 	sprintf(gidstr, "%d", argp->key.gid);
63 	return (_nss_nis_lookup(be, argp, 0, "group.bygid", gidstr, 0));
64 }
65 
66 static nss_status_t
67 getbymember(be, a)
68 	nis_backend_ptr_t	be;
69 	void			*a;
70 {
71 	struct nss_groupsbymem	*argp = (struct nss_groupsbymem *)a;
72 
73 	if (strcmp(argp->username, "root") == 0) {
74 		/*
75 		 * Assume that "root" can only sensibly be in /etc/group,
76 		 *   not in NIS or NIS+
77 		 * If we don't do this, a hung name-service may cause
78 		 *   a root login or su to hang.
79 		 */
80 		return (NSS_NOTFOUND);
81 	}
82 
83 	if (argp->force_slow_way != 1) {
84 		switch (netid_lookup(argp)) {
85 		case NSS_SUCCESS:
86 			/*
87 			 * Return SUCESS only if array is full. Explained
88 			 * in <nss_dbdefs.h>.
89 			 */
90 			return ((argp->numgids == argp->maxgids)
91 			    ? NSS_SUCCESS
92 			    : NSS_NOTFOUND);
93 		case NSS_NOTFOUND:
94 		case NSS_UNAVAIL:
95 			/*
96 			 * Failover to group map search if no luck with netid.
97 			 */
98 			break;
99 		case NSS_TRYAGAIN:
100 			return (NSS_TRYAGAIN);
101 		}
102 	}
103 
104 	return (_nss_nis_do_all(be, argp, argp->username,
105 				(nis_do_all_func_t)argp->process_cstr));
106 }
107 
108 static nis_backend_op_t group_ops[] = {
109 	_nss_nis_destr,
110 	_nss_nis_endent,
111 	_nss_nis_setent,
112 	_nss_nis_getent_rigid,
113 	getbyname,
114 	getbygid,
115 	getbymember
116 };
117 
118 /*ARGSUSED*/
119 nss_backend_t *
120 _nss_nis_group_constr(dummy1, dummy2, dummy3)
121 	const char	*dummy1, *dummy2, *dummy3;
122 {
123 	return (_nss_nis_constr(group_ops,
124 				sizeof (group_ops) / sizeof (group_ops[0]),
125 				"group.byname"));
126 }
127 
128 /*
129  * Add gid to gid_array if it's not already there. gid_array must have room
130  * for one more entry.  Return new size of array.
131  */
132 static int
133 add_gid(gid_t gid_array[], int numgids, gid_t gid)
134 {
135 	int i = 0;
136 
137 	for (i = 0; i < numgids; i++) {
138 		if (gid_array[i] == gid) {
139 			return (numgids);
140 		}
141 	}
142 	gid_array[numgids++] = gid;
143 	return (numgids);
144 }
145 
146 /*
147  * Given buf, a null-terminated string containing the result of a successful
148  * netid lookup, add the gids to the gid_array.  The string may contain extra
149  * whitesapce.  On parse error, the valid portion of the gid_array is not
150  * modified.
151  */
152 static int
153 parse_netid(const char *buf, gid_t gid_array[], int maxgids, int *numgids_ptr)
154 {
155 	int	numgids = *numgids_ptr;
156 	char	*buf_next;
157 	int	buflen = strlen(buf);
158 	gid_t	gid;
159 	long	value;
160 
161 	/* Scan past "<uid>:" */
162 	while (isspace(*buf) || isdigit(*buf)) {
163 		buf++;
164 	}
165 
166 	if (*buf++ != ':') {
167 		return (NSS_STR_PARSE_PARSE);
168 	}
169 
170 	/* buf should now point to a comma-separated list of gids */
171 	while (*buf != '\0' && *buf != '\n') {
172 		errno = 0;
173 		value = strtol(buf, &buf_next, 10);
174 
175 		if (buf == buf_next) {
176 			return (NSS_STR_PARSE_PARSE);
177 		} else if ((value == LONG_MAX && errno == ERANGE) ||
178 		    (ulong_t)value > INT_MAX) {
179 			return (NSS_STR_PARSE_ERANGE);
180 		}
181 
182 		gid = (gid_t)value;
183 		if (numgids < maxgids) {
184 			numgids = add_gid(gid_array, numgids, gid);
185 		}
186 		buf = buf_next;
187 		if (*buf == ',') {
188 			buf++;
189 		}
190 	}
191 	*numgids_ptr = numgids;
192 	return (NSS_STR_PARSE_SUCCESS);
193 }
194 
195 
196 /*
197  * Perform a lookup in the netid map.  Fill in the gid_array if successful.
198  * Return values are like those for _nss_nis_lookup().
199  */
200 static nss_status_t
201 netid_lookup(struct nss_groupsbymem *argp)
202 {
203 	const char	*domain = _nss_nis_domain();
204 	struct passwd	pw;
205 	char		pwbuf[NSS_BUFLEN_PASSWD];
206 	char		netname[MAXNETNAMELEN + 1];
207 	nss_status_t	res;
208 	char		*val;
209 	int		vallen;
210 	char		*comment;
211 	int		parse_res;
212 	char		*lasts;
213 
214 	/*
215 	 * Need to build up the netname for the user manually. Can't use
216 	 * user2netname() rpc library call, since that does all sorts of
217 	 * extra stuff based upon its own private name-service switch.
218 	 *
219 	 * Note that "root" has no user netname so return in error.
220 	 */
221 	if ((getpwnam_r(argp->username, &pw, pwbuf, sizeof (pwbuf)) == NULL) ||
222 	    (pw.pw_uid == 0)) {
223 		return (NSS_UNAVAIL);
224 	}
225 	if (snprintf(netname, MAXNETNAMELEN + 1, "unix.%d@%s",
226 	    pw.pw_uid, domain) < 0) {
227 		return (NSS_UNAVAIL);
228 	}
229 
230 	if ((res = _nss_nis_ypmatch(domain, "netid.byname", netname,
231 			&val, &vallen, 0)) != NSS_SUCCESS) {
232 		return (res);
233 	}
234 
235 	strtok_r(val, "#", &lasts);
236 
237 	parse_res = parse_netid(val, argp->gid_array, argp->maxgids,
238 			&argp->numgids);
239 	free(val);
240 	return ((parse_res == NSS_STR_PARSE_SUCCESS)
241 		? NSS_SUCCESS
242 		: NSS_NOTFOUND);
243 }
244