xref: /titanic_41/usr/src/lib/nsswitch/nis/common/getgrent.c (revision 7ff178cd8db129d385d3177eb20744d3b6efc59b)
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 2009 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 #include <grp.h>
31 #include <pwd.h>
32 #include "nis_common.h"
33 #include <ctype.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <rpc/auth.h>	/* for MAXNETNAMELEN */
37 
38 static nss_status_t netid_lookup(struct nss_groupsbymem *argp);
39 
40 static nss_status_t
41 getbyname(be, a)
42 	nis_backend_ptr_t	be;
43 	void			*a;
44 {
45 	nss_XbyY_args_t		*argp = (nss_XbyY_args_t *)a;
46 
47 	return (_nss_nis_lookup(be, argp, 0,
48 				"group.byname", argp->key.name, 0));
49 }
50 
51 static nss_status_t
52 getbygid(be, a)
53 	nis_backend_ptr_t	be;
54 	void			*a;
55 {
56 	nss_XbyY_args_t		*argp = (nss_XbyY_args_t *)a;
57 	char			gidstr[12];	/* More than enough */
58 
59 	if (argp->key.gid > MAXUID)
60 		return (NSS_NOTFOUND);
61 	(void) snprintf(gidstr, 12, "%d", argp->key.gid);
62 	return (_nss_nis_lookup(be, argp, 0, "group.bygid", gidstr, 0));
63 }
64 
65 /*
66  * Validates group entry replacing gid > MAXUID by GID_NOBODY.
67  */
68 int
69 validate_group_ids(char **linepp, int *linelenp, int allocbuf)
70 {
71 	char	*linep, *limit, *gidp, *newline;
72 	ulong_t	gid;
73 	int	oldgidlen, idlen;
74 	int	linelen = *linelenp, newlinelen;
75 
76 	linep = *linepp;
77 	limit = linep + linelen;
78 
79 	/* +/- entries valid for compat source only */
80 	if (linelen == 0 || *linep == '+' || *linep == '-')
81 		return (NSS_STR_PARSE_SUCCESS);
82 
83 	while (linep < limit && *linep++ != ':') /* skip groupname */
84 		continue;
85 	while (linep < limit && *linep++ != ':') /* skip password */
86 		continue;
87 	if (linep == limit)
88 		return (NSS_STR_PARSE_PARSE);
89 
90 	gidp = linep;
91 	gid = strtoul(gidp, (char **)&linep, 10); /* grab gid */
92 	oldgidlen = linep - gidp;
93 	if (linep >= limit || oldgidlen == 0)
94 		return (NSS_STR_PARSE_PARSE);
95 
96 	if (gid <= MAXUID)
97 		return (NSS_STR_PARSE_SUCCESS);
98 
99 	idlen = snprintf(NULL, 0, "%u", GID_NOBODY);
100 	newlinelen = linelen + idlen - oldgidlen;
101 	if (newlinelen > linelen) {
102 		/* need a larger buffer */
103 		if (!allocbuf || (newline = malloc(newlinelen + 1)) == NULL)
104 			return (NSS_STR_PARSE_ERANGE);
105 		/* Replace ephemeral ids by ID_NOBODY in the new buffer */
106 		*(gidp - 1) = '\0';
107 		(void) snprintf(newline, newlinelen + 1, "%s:%u%s",
108 		    *linepp, GID_NOBODY, linep);
109 		free(*linepp);
110 		*linepp = newline;
111 		*linelenp = newlinelen;
112 		return (NSS_STR_PARSE_SUCCESS);
113 	}
114 
115 	/* Replace ephemeral gid by GID_NOBODY in the same buffer */
116 	(void) bcopy(linep, gidp + idlen, limit - linep + 1);
117 	(void) snprintf(gidp, idlen + 1, "%u", GID_NOBODY);
118 	*(gidp + idlen) = ':';
119 	*linelenp = newlinelen;
120 	return (NSS_STR_PARSE_SUCCESS);
121 }
122 
123 static nss_status_t
124 getbymember(be, a)
125 	nis_backend_ptr_t	be;
126 	void			*a;
127 {
128 	struct nss_groupsbymem	*argp = (struct nss_groupsbymem *)a;
129 
130 	if (strcmp(argp->username, "root") == 0) {
131 		/*
132 		 * Assume that "root" can only sensibly be in /etc/group,
133 		 *   not in NIS
134 		 * If we don't do this, a hung name-service may cause
135 		 *   a root login or su to hang.
136 		 */
137 		return (NSS_NOTFOUND);
138 	}
139 
140 	if (argp->force_slow_way != 1) {
141 		switch (netid_lookup(argp)) {
142 		case NSS_SUCCESS:
143 			/*
144 			 * Return SUCESS only if array is full. Explained
145 			 * in <nss_dbdefs.h>.
146 			 */
147 			return ((argp->numgids == argp->maxgids)
148 			    ? NSS_SUCCESS
149 			    : NSS_NOTFOUND);
150 		case NSS_NOTFOUND:
151 		case NSS_UNAVAIL:
152 			/*
153 			 * Failover to group map search if no luck with netid.
154 			 */
155 			break;
156 		case NSS_TRYAGAIN:
157 			return (NSS_TRYAGAIN);
158 		}
159 	}
160 
161 	return (_nss_nis_do_all(be, argp, argp->username,
162 				(nis_do_all_func_t)argp->process_cstr));
163 }
164 
165 static nis_backend_op_t group_ops[] = {
166 	_nss_nis_destr,
167 	_nss_nis_endent,
168 	_nss_nis_setent,
169 	_nss_nis_getent_rigid,
170 	getbyname,
171 	getbygid,
172 	getbymember
173 };
174 
175 /*ARGSUSED*/
176 nss_backend_t *
177 _nss_nis_group_constr(dummy1, dummy2, dummy3)
178 	const char	*dummy1, *dummy2, *dummy3;
179 {
180 	return (_nss_nis_constr(group_ops,
181 				sizeof (group_ops) / sizeof (group_ops[0]),
182 				"group.byname"));
183 }
184 
185 /*
186  * Add gid to gid_array if it's not already there. gid_array must have room
187  * for one more entry.  Return new size of array.
188  */
189 static int
190 add_gid(gid_t gid_array[], int numgids, gid_t gid)
191 {
192 	int i = 0;
193 
194 	for (i = 0; i < numgids; i++) {
195 		if (gid_array[i] == gid) {
196 			return (numgids);
197 		}
198 	}
199 	gid_array[numgids++] = gid;
200 	return (numgids);
201 }
202 
203 /*
204  * Given buf, a null-terminated string containing the result of a successful
205  * netid lookup, add the gids to the gid_array.  The string may contain extra
206  * whitesapce.  On parse error, the valid portion of the gid_array is not
207  * modified.
208  */
209 static int
210 parse_netid(const char *buf, gid_t gid_array[], int maxgids, int *numgids_ptr)
211 {
212 	int	numgids = *numgids_ptr;
213 	char	*buf_next;
214 	gid_t	gid;
215 	long	value;
216 
217 	/* Scan past "<uid>:" */
218 	while (isspace(*buf) || isdigit(*buf)) {
219 		buf++;
220 	}
221 
222 	if (*buf++ != ':') {
223 		return (NSS_STR_PARSE_PARSE);
224 	}
225 
226 	/* buf should now point to a comma-separated list of gids */
227 	while (*buf != '\0' && *buf != '\n') {
228 		errno = 0;
229 		value = strtol(buf, &buf_next, 10);
230 
231 		if (buf == buf_next) {
232 			return (NSS_STR_PARSE_PARSE);
233 		} else if ((value == LONG_MAX && errno == ERANGE) ||
234 		    (ulong_t)value > INT_MAX) {
235 			return (NSS_STR_PARSE_ERANGE);
236 		}
237 
238 		gid = (gid_t)value;
239 		if (numgids < maxgids) {
240 			numgids = add_gid(gid_array, numgids, gid);
241 		}
242 		buf = buf_next;
243 		if (*buf == ',') {
244 			buf++;
245 		}
246 	}
247 	*numgids_ptr = numgids;
248 	return (NSS_STR_PARSE_SUCCESS);
249 }
250 
251 
252 /*
253  * Perform a lookup in the netid map.  Fill in the gid_array if successful.
254  * Return values are like those for _nss_nis_lookup().
255  */
256 static nss_status_t
257 netid_lookup(struct nss_groupsbymem *argp)
258 {
259 	const char	*domain = _nss_nis_domain();
260 	struct passwd	pw;
261 	char		pwbuf[NSS_BUFLEN_PASSWD];
262 	char		netname[MAXNETNAMELEN + 1];
263 	nss_status_t	res;
264 	char		*val;
265 	int		vallen;
266 	int		parse_res;
267 	char		*lasts;
268 
269 	/*
270 	 * Need to build up the netname for the user manually. Can't use
271 	 * user2netname() rpc library call, since that does all sorts of
272 	 * extra stuff based upon its own private name-service switch.
273 	 *
274 	 * Note that "root" has no user netname so return in error.
275 	 */
276 	if ((getpwnam_r(argp->username, &pw, pwbuf, sizeof (pwbuf)) == NULL) ||
277 	    (pw.pw_uid == 0)) {
278 		return (NSS_UNAVAIL);
279 	}
280 	if (snprintf(netname, MAXNETNAMELEN + 1, "unix.%d@%s",
281 	    pw.pw_uid, domain) < 0) {
282 		return (NSS_UNAVAIL);
283 	}
284 
285 	if ((res = _nss_nis_ypmatch(domain, "netid.byname", netname,
286 	    &val, &vallen, 0)) != NSS_SUCCESS) {
287 		return (res);
288 	}
289 
290 	(void) strtok_r(val, "#", &lasts);
291 
292 	parse_res = parse_netid(val, argp->gid_array, argp->maxgids,
293 	    &argp->numgids);
294 	free(val);
295 	return ((parse_res == NSS_STR_PARSE_SUCCESS)
296 	    ? NSS_SUCCESS : NSS_NOTFOUND);
297 }
298