xref: /illumos-gate/usr/src/lib/libsec/common/aclsort.c (revision 9164a50bf932130cbb5097a16f6986873ce0e6e5)
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 /*
24  * Copyright (c) 1993-1997 by Sun Microsystems, Inc.
25  * All rights reserved
26  */
27 
28 /*LINTLIBRARY*/
29 
30 /*
31  * aclsort():
32  *	Sort an ACL by entry type according to the following order:
33  *	USER_OBJ, USER, GROUP_OBJ, GROUP, CLASS_OBJ, OTHER_OBJ
34  *	DEF_USER_OBJ, DEF_USER, DEF_GROUP_OBJ, DEF_GROUP, DEF_CLASS_OBJ,
35  *	DEF_OTHER_OBJ.
36  *	For USER, GROUP, DEF_USER, and DEF_GROUP entries, the entries
37  *	are further sorted by ids.
38  */
39 
40 #include <stdlib.h>
41 #include <sys/acl.h>
42 
43 #define	TOTAL_ENTRY_TYPES	12
44 
45 /*
46  * This maps the entry defined value to a value for sorting.
47  * These values may not be the same. It is easier to add an
48  * entry type with this map.
49  *
50  * Because the defines and sorting order are not the same,
51  * the following map_to_sort table is needed.
52  */
53 struct map {
54 	int	sort_order;
55 	int	entry_type;
56 };
57 
58 static struct map map_to_sort[] = {
59 		{0, 0}, /* UNUSED */
60 		{1,	USER_OBJ},
61 		{2,	USER},
62 		{3, 	GROUP_OBJ},
63 		{4,	GROUP},
64 		{5,	CLASS_OBJ},
65 		{6, 	OTHER_OBJ},
66 		{7, 	DEF_USER_OBJ},
67 		{8, 	DEF_USER},
68 		{9, 	DEF_GROUP_OBJ},
69 		{10,	DEF_GROUP},
70 		{11,	DEF_CLASS_OBJ},
71 		{12,	DEF_OTHER_OBJ},
72 };
73 
74 static int entrycmp(const aclent_t *, const aclent_t *);
75 static int idcmp(const aclent_t *, const aclent_t *);
76 static void sortid(aclent_t *, int, int);
77 
78 int
79 aclsort(int nentries, int calcmask, aclent_t *aclbufp)
80 {
81 	aclent_t		*tp;
82 	unsigned int		newmask = 0;
83 	int			which;
84 	int			i;
85 	int			k;
86 
87 	/* check validity first before sorting */
88 	if (aclcheck(aclbufp, nentries, &which) != 0)
89 		return (-1);
90 
91 	/*
92 	 * Performance enhancement:
93 	 * We change entry type to sort order in the ACL, do the sorting.
94 	 * We then change sort order back to entry type.
95 	 * This makes entrycmp() very "light" and thus improves performance.
96 	 * Contrast to original implementation that had to find out
97 	 * the sorting order each time it is called.
98 	 */
99 	for (tp = aclbufp, i = 0; i < nentries; tp++, i++) {
100 		for (k = 1; k <= TOTAL_ENTRY_TYPES; k++) {
101 			if (tp->a_type == map_to_sort[k].entry_type) {
102 				tp->a_type = map_to_sort[k].sort_order;
103 				break;
104 			}
105 		}
106 	}
107 
108 	/* typecast to remove incompatible type warning */
109 	qsort(aclbufp, nentries, sizeof (aclent_t),
110 	    (int (*)(const void *, const void *))entrycmp);
111 
112 	for (tp = aclbufp, i = 0; i < nentries; tp++, i++) {
113 		for (k = 1; k <= TOTAL_ENTRY_TYPES; k++) {
114 			if (tp->a_type == map_to_sort[k].sort_order) {
115 				tp->a_type = map_to_sort[k].entry_type;
116 				break;
117 			}
118 		}
119 	}
120 
121 	/*
122 	 * Start sorting id within USER and GROUP
123 	 * sortid() could return a pointer and entries left
124 	 * so that we dont have to search from the beginning
125 	 *  every time it calls
126 	 */
127 	sortid(aclbufp, nentries, USER);
128 	sortid(aclbufp, nentries, GROUP);
129 	sortid(aclbufp, nentries, DEF_USER);
130 	sortid(aclbufp, nentries, DEF_GROUP);
131 
132 	/*
133 	 * Recalculate mask entry
134 	 */
135 	if (calcmask != 0) {
136 		/*
137 		 * At this point, ACL is valid and sorted. We may find a
138 		 * CLASS_OBJ entry and stop. Because of the case of minimum ACL,
139 		 * we still have to check till OTHER_OBJ entry is shown.
140 		 */
141 		for (tp = aclbufp; tp->a_type != OTHER_OBJ; tp++) {
142 			if (tp->a_type == USER || tp->a_type == GROUP ||
143 			    tp->a_type == GROUP_OBJ)
144 				newmask |= tp->a_perm;
145 			if (tp->a_type == CLASS_OBJ)
146 				break;
147 		}
148 		if (tp->a_type == CLASS_OBJ)
149 			tp->a_perm = (unsigned char)newmask;
150 	}
151 	return (0);
152 }
153 
154 /*
155  * sortid() sorts the ids with the same entry type in increasing order
156  */
157 static void
158 sortid(aclent_t *ap, int cnt, int type)
159 {
160 	aclent_t	*tp;
161 	aclent_t	*startp; /* start of the desired entry type */
162 	int		howmany;
163 
164 	for (tp = ap; cnt-- > 0; tp++) {
165 		if (tp->a_type != type)
166 			continue;
167 		startp = tp;
168 		howmany = 1;
169 		for (tp++, cnt--; cnt > 0 && tp->a_type == type; tp++, cnt--)
170 			howmany++;
171 		/* typecast to remove incompatible type warning */
172 		qsort(startp, howmany, sizeof (aclent_t),
173 		    (int (*)(const void*, const void*))idcmp);
174 	}
175 }
176 
177 /*
178  * compare the field a_type
179  */
180 static int
181 entrycmp(const aclent_t *i, const aclent_t *j)
182 {
183 	return ((int)(i->a_type) - (int)(j->a_type));
184 }
185 
186 /*
187  * compare the field a_id
188  */
189 static int
190 idcmp(const aclent_t *i, const aclent_t *j)
191 {
192 	return ((int)(i->a_id) - (int)(j->a_id));
193 }
194