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 2007 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
26 /* All Rights Reserved */
27
28
29 #pragma ident "%Z%%M% %I% %E% SMI" /* SVr4.0 1.5 */
30
31 #include <sys/types.h>
32 #include <stdio.h>
33 #include <userdefs.h>
34
35 #include <sys/param.h>
36 #ifndef MAXUID
37 #include <limits.h>
38 #ifdef UID_MAX
39 #define MAXUID UID_MAX
40 #else
41 #define MAXUID 60000
42 #endif
43 #endif
44
45 /*
46 * Check to see that the gid is not a reserved gid
47 * -- nobody, noaccess or nogroup
48 */
49 static int
isvalidgid(gid_t gid)50 isvalidgid(gid_t gid)
51 {
52 return (gid != 60001 && gid != 60002 && gid != 65534);
53 }
54
55 gid_t
findnextgid()56 findnextgid()
57 {
58 FILE *fptr;
59 gid_t last, next;
60 gid_t gid;
61
62 /*
63 * Sort the used GIDs in decreasing order to return MAXUSED + 1
64 */
65 if ((fptr = popen("exec sh -c "
66 "\"getent group|cut -f3 -d:|sort -nr|uniq \" 2>/dev/null",
67 "r")) == NULL)
68 return (-1);
69
70 if (fscanf(fptr, "%u\n", &next) == EOF) {
71 (void) pclose(fptr);
72 return (DEFRID + 1);
73 }
74
75 /*
76 * 'next' is now the highest allocated gid.
77 *
78 * The simplest allocation is where we just add one, and obtain
79 * a valid gid. If this fails look for a hole in the gid range ..
80 */
81
82 last = MAXUID; /* upper limit */
83 gid = -1; /* start invalid */
84 do {
85 if (!isvalidgid(next))
86 continue;
87
88 if (next <= DEFRID) {
89 if (last != DEFRID + 1)
90 gid = DEFRID + 1;
91 break;
92 }
93
94 if ((gid = next + 1) != last) {
95 while (!isvalidgid(gid))
96 gid++;
97 if (gid > 0 && gid < last)
98 break;
99 }
100
101 gid = -1;
102 last = next;
103
104 } while (fscanf(fptr, "%u\n", &next) != EOF);
105
106 (void) pclose(fptr);
107
108 return (gid);
109 }
110