xref: /titanic_52/usr/src/lib/nsswitch/nis/common/getgrent.c (revision d51e90740114c60620c0febffd4d3ce6e280a107)
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 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * nis/getgrent.c -- "nis" backend for nsswitch "group" database
28  */
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include <grp.h>
33 #include <pwd.h>
34 #include "nis_common.h"
35 #include <ctype.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <rpc/auth.h>	/* for MAXNETNAMELEN */
39 
40 static nss_status_t netid_lookup(struct nss_groupsbymem *argp);
41 
42 static nss_status_t
43 getbyname(be, a)
44 	nis_backend_ptr_t	be;
45 	void			*a;
46 {
47 	nss_XbyY_args_t		*argp = (nss_XbyY_args_t *)a;
48 
49 	return (_nss_nis_lookup(be, argp, 0,
50 				"group.byname", argp->key.name, 0));
51 }
52 
53 static nss_status_t
54 getbygid(be, a)
55 	nis_backend_ptr_t	be;
56 	void			*a;
57 {
58 	nss_XbyY_args_t		*argp = (nss_XbyY_args_t *)a;
59 	char			gidstr[12];	/* More than enough */
60 
61 	(void) snprintf(gidstr, 12, "%d", argp->key.gid);
62 	return (_nss_nis_lookup(be, argp, 0, "group.bygid", gidstr, 0));
63 }
64 
65 static nss_status_t
66 getbymember(be, a)
67 	nis_backend_ptr_t	be;
68 	void			*a;
69 {
70 	struct nss_groupsbymem	*argp = (struct nss_groupsbymem *)a;
71 
72 	if (strcmp(argp->username, "root") == 0) {
73 		/*
74 		 * Assume that "root" can only sensibly be in /etc/group,
75 		 *   not in NIS or NIS+
76 		 * If we don't do this, a hung name-service may cause
77 		 *   a root login or su to hang.
78 		 */
79 		return (NSS_NOTFOUND);
80 	}
81 
82 	if (argp->force_slow_way != 1) {
83 		switch (netid_lookup(argp)) {
84 		case NSS_SUCCESS:
85 			/*
86 			 * Return SUCESS only if array is full. Explained
87 			 * in <nss_dbdefs.h>.
88 			 */
89 			return ((argp->numgids == argp->maxgids)
90 			    ? NSS_SUCCESS
91 			    : NSS_NOTFOUND);
92 		case NSS_NOTFOUND:
93 		case NSS_UNAVAIL:
94 			/*
95 			 * Failover to group map search if no luck with netid.
96 			 */
97 			break;
98 		case NSS_TRYAGAIN:
99 			return (NSS_TRYAGAIN);
100 		}
101 	}
102 
103 	return (_nss_nis_do_all(be, argp, argp->username,
104 				(nis_do_all_func_t)argp->process_cstr));
105 }
106 
107 static nis_backend_op_t group_ops[] = {
108 	_nss_nis_destr,
109 	_nss_nis_endent,
110 	_nss_nis_setent,
111 	_nss_nis_getent_rigid,
112 	getbyname,
113 	getbygid,
114 	getbymember
115 };
116 
117 /*ARGSUSED*/
118 nss_backend_t *
119 _nss_nis_group_constr(dummy1, dummy2, dummy3)
120 	const char	*dummy1, *dummy2, *dummy3;
121 {
122 	return (_nss_nis_constr(group_ops,
123 				sizeof (group_ops) / sizeof (group_ops[0]),
124 				"group.byname"));
125 }
126 
127 /*
128  * Add gid to gid_array if it's not already there. gid_array must have room
129  * for one more entry.  Return new size of array.
130  */
131 static int
132 add_gid(gid_t gid_array[], int numgids, gid_t gid)
133 {
134 	int i = 0;
135 
136 	for (i = 0; i < numgids; i++) {
137 		if (gid_array[i] == gid) {
138 			return (numgids);
139 		}
140 	}
141 	gid_array[numgids++] = gid;
142 	return (numgids);
143 }
144 
145 /*
146  * Given buf, a null-terminated string containing the result of a successful
147  * netid lookup, add the gids to the gid_array.  The string may contain extra
148  * whitesapce.  On parse error, the valid portion of the gid_array is not
149  * modified.
150  */
151 static int
152 parse_netid(const char *buf, gid_t gid_array[], int maxgids, int *numgids_ptr)
153 {
154 	int	numgids = *numgids_ptr;
155 	char	*buf_next;
156 	gid_t	gid;
157 	long	value;
158 
159 	/* Scan past "<uid>:" */
160 	while (isspace(*buf) || isdigit(*buf)) {
161 		buf++;
162 	}
163 
164 	if (*buf++ != ':') {
165 		return (NSS_STR_PARSE_PARSE);
166 	}
167 
168 	/* buf should now point to a comma-separated list of gids */
169 	while (*buf != '\0' && *buf != '\n') {
170 		errno = 0;
171 		value = strtol(buf, &buf_next, 10);
172 
173 		if (buf == buf_next) {
174 			return (NSS_STR_PARSE_PARSE);
175 		} else if ((value == LONG_MAX && errno == ERANGE) ||
176 		    (ulong_t)value > INT_MAX) {
177 			return (NSS_STR_PARSE_ERANGE);
178 		}
179 
180 		gid = (gid_t)value;
181 		if (numgids < maxgids) {
182 			numgids = add_gid(gid_array, numgids, gid);
183 		}
184 		buf = buf_next;
185 		if (*buf == ',') {
186 			buf++;
187 		}
188 	}
189 	*numgids_ptr = numgids;
190 	return (NSS_STR_PARSE_SUCCESS);
191 }
192 
193 
194 /*
195  * Perform a lookup in the netid map.  Fill in the gid_array if successful.
196  * Return values are like those for _nss_nis_lookup().
197  */
198 static nss_status_t
199 netid_lookup(struct nss_groupsbymem *argp)
200 {
201 	const char	*domain = _nss_nis_domain();
202 	struct passwd	pw;
203 	char		pwbuf[NSS_BUFLEN_PASSWD];
204 	char		netname[MAXNETNAMELEN + 1];
205 	nss_status_t	res;
206 	char		*val;
207 	int		vallen;
208 	int		parse_res;
209 	char		*lasts;
210 
211 	/*
212 	 * Need to build up the netname for the user manually. Can't use
213 	 * user2netname() rpc library call, since that does all sorts of
214 	 * extra stuff based upon its own private name-service switch.
215 	 *
216 	 * Note that "root" has no user netname so return in error.
217 	 */
218 	if ((getpwnam_r(argp->username, &pw, pwbuf, sizeof (pwbuf)) == NULL) ||
219 	    (pw.pw_uid == 0)) {
220 		return (NSS_UNAVAIL);
221 	}
222 	if (snprintf(netname, MAXNETNAMELEN + 1, "unix.%d@%s",
223 	    pw.pw_uid, domain) < 0) {
224 		return (NSS_UNAVAIL);
225 	}
226 
227 	if ((res = _nss_nis_ypmatch(domain, "netid.byname", netname,
228 			&val, &vallen, 0)) != NSS_SUCCESS) {
229 		return (res);
230 	}
231 
232 	(void) strtok_r(val, "#", &lasts);
233 
234 	parse_res = parse_netid(val, argp->gid_array, argp->maxgids,
235 			&argp->numgids);
236 	free(val);
237 	return ((parse_res == NSS_STR_PARSE_SUCCESS)
238 		? NSS_SUCCESS
239 		: NSS_NOTFOUND);
240 }
241