xref: /openbsd-src/lib/libc/gen/getgrouplist.c (revision 850e275390052b330d93020bf619a739a3c277ac)
1 /*	$OpenBSD: getgrouplist.c,v 1.15 2008/08/23 10:08:02 chl Exp $ */
2 /*
3  * Copyright (c) 1991, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 /*
32  * get credential
33  */
34 #include <sys/types.h>
35 #include <sys/limits.h>
36 #include <string.h>
37 #include <unistd.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <grp.h>
41 #include <pwd.h>
42 
43 #include <rpc/rpc.h>
44 #include <rpcsvc/yp.h>
45 #include <rpcsvc/ypclnt.h>
46 
47 int
48 getgrouplist(const char *uname, gid_t agroup, gid_t *groups, int *grpcnt)
49 {
50 	int i, ngroups = 0, ret = 0, maxgroups = *grpcnt, bail;
51 	int needyp = 0, foundyp = 0;
52 	extern struct group *_getgrent_yp(int *);
53 	struct group *grp;
54 
55 	/*
56 	 * install primary group
57 	 */
58 	if (ngroups >= maxgroups) {
59 		*grpcnt = ngroups;
60 		return (-1);
61 	}
62 	groups[ngroups++] = agroup;
63 
64 	/*
65 	 * Scan the group file to find additional groups.
66 	 */
67 	setgrent();
68 	while ((grp = _getgrent_yp(&foundyp)) || foundyp) {
69 		if (foundyp) {
70 			needyp = 1;
71 			foundyp = 0;
72 			continue;
73 		}
74 		if (grp->gr_gid == agroup)
75 			continue;
76 		for (bail = 0, i = 0; bail == 0 && i < ngroups; i++)
77 			if (groups[i] == grp->gr_gid)
78 				bail = 1;
79 		if (bail)
80 			continue;
81 		for (i = 0; grp->gr_mem[i]; i++) {
82 			if (!strcmp(grp->gr_mem[i], uname)) {
83 				if (ngroups >= maxgroups) {
84 					ret = -1;
85 					goto out;
86 				}
87 				groups[ngroups++] = grp->gr_gid;
88 				break;
89 			}
90 		}
91 	}
92 
93 #ifdef YP
94 	/*
95 	 * If we were told that there is a YP marker, look there now.
96 	 */
97 	if (needyp) {
98 		char buf[1024], *ypdata = NULL, *key, *p;
99 		const char *errstr = NULL;
100 		static char *__ypdomain;
101 		struct passwd pwstore;
102 		int r, ypdatalen;
103 		gid_t gid;
104 		uid_t uid;
105 
106 		if (!__ypdomain) {
107 			if (_yp_check(&__ypdomain) == 0) {
108 				goto ypout;
109 			}
110 		}
111 
112 		if (getpwnam_r(uname, &pwstore, buf, sizeof buf, NULL))
113 			goto ypout;
114 
115 		asprintf(&key, "unix.%u@%s", pwstore.pw_uid, __ypdomain);
116 		if (key == NULL)
117 			goto ypout;
118 		r = yp_match(__ypdomain, "netid.byname", key,
119 		    (int)strlen(key), &ypdata, &ypdatalen);
120 		free(key);
121 		if (r != 0)
122 			goto ypout;
123 
124 		/* Parse the "uid:gid[,gid,gid[,...]]" string. */
125 		p = strchr(ypdata, ':');
126 		if (!p)
127 			goto ypout;
128 		*p++ = '\0';
129 		uid = (uid_t)strtonum(ypdata, 0, UID_MAX, &errstr);
130 		if (errstr || uid != pwstore.pw_uid)
131 			goto ypout;
132 		while (p && *p) {
133 			char *start = p;
134 
135 			p = strchr(start, ',');
136 			if (p)
137 				*p++ = '\0';
138 			gid = (uid_t)strtonum(start, 0, GID_MAX, &errstr);
139 			if (errstr)
140 				goto ypout;
141 
142 			/* Add new groups to the group list */
143 			for (i = 0; i < ngroups; i++) {
144 				if (groups[i] == gid)
145 					break;
146 			}
147 			if (i == ngroups) {
148 				if (ngroups >= maxgroups) {
149 					ret = -1;
150 					goto ypout;
151 				}
152 				groups[ngroups++] = gid;
153 			}
154 		}
155 ypout:
156 		if (ypdata)
157 			free(ypdata);
158 		goto out;
159 	}
160 #endif /* YP */
161 
162 out:
163 	endgrent();
164 	*grpcnt = ngroups;
165 	return (ret);
166 }
167