1 /*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (c) 1995
5 * Bill Paul <[email protected]>. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by Bill Paul.
18 * 4. Neither the name of the author nor the names of any co-contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <sys/types.h>
39 #include "hash.h"
40
41 #ifndef lint
42 static const char rcsid[] =
43 "$FreeBSD$";
44 #endif /* not lint */
45
46 /*
47 * This hash function is stolen directly from the
48 * Berkeley DB package. It already exists inside libc, but
49 * it's declared static which prevents us from calling it
50 * from here.
51 */
52 /*
53 * OZ's original sdbm hash
54 */
55 u_int32_t
hash(const void * keyarg,size_t len)56 hash(const void *keyarg, size_t len)
57 {
58 const u_char *key;
59 size_t loop;
60 u_int32_t h;
61
62 #define HASHC h = *key++ + 65599 * h
63
64 h = 0;
65 key = keyarg;
66 if (len > 0) {
67 loop = (len + 8 - 1) >> 3;
68
69 switch (len & (8 - 1)) {
70 case 0:
71 do {
72 HASHC;
73 /* FALLTHROUGH */
74 case 7:
75 HASHC;
76 /* FALLTHROUGH */
77 case 6:
78 HASHC;
79 /* FALLTHROUGH */
80 case 5:
81 HASHC;
82 /* FALLTHROUGH */
83 case 4:
84 HASHC;
85 /* FALLTHROUGH */
86 case 3:
87 HASHC;
88 /* FALLTHROUGH */
89 case 2:
90 HASHC;
91 /* FALLTHROUGH */
92 case 1:
93 HASHC;
94 } while (--loop);
95 }
96 }
97 return (h);
98 }
99
100 /*
101 * Generate a hash value for a given key (character string).
102 * We mask off all but the lower 8 bits since our table array
103 * can only hole 256 elements.
104 */
hashkey(char * key)105 u_int32_t hashkey(char *key)
106 {
107
108 if (key == NULL)
109 return (-1);
110 return(hash((void *)key, strlen(key)) & HASH_MASK);
111 }
112
113 /* Find an entry in the hash table (may be hanging off a linked list). */
lookup(struct member_entry * table[],char * key)114 struct grouplist *lookup(struct member_entry *table[], char *key)
115 {
116 struct member_entry *cur;
117
118 cur = table[hashkey(key)];
119
120 while (cur) {
121 if (!strcmp(cur->key, key))
122 return(cur->groups);
123 cur = cur->next;
124 }
125
126 return(NULL);
127 }
128
129 struct grouplist dummy = { 99999, NULL };
130
131 /*
132 * Store a group member entry and/or update its grouplist.
133 */
mstore(struct member_entry * table[],char * key,int gid,int dup)134 void mstore (struct member_entry *table[], char *key, int gid, int dup)
135 {
136 struct member_entry *cur, *new;
137 struct grouplist *tmp;
138 u_int32_t i;
139
140 i = hashkey(key);
141 cur = table[i];
142
143 if (!dup) {
144 tmp = (struct grouplist *)malloc(sizeof(struct grouplist));
145 tmp->groupid = gid;
146 tmp->next = NULL;
147 }
148
149 /* Check if all we have to do is insert a new groupname. */
150 while (cur) {
151 if (!dup && !strcmp(cur->key, key)) {
152 tmp->next = cur->groups;
153 cur->groups = tmp;
154 return;
155 }
156 cur = cur->next;
157 }
158
159 /* Didn't find a match -- add the whole mess to the table. */
160 new = (struct member_entry *)malloc(sizeof(struct member_entry));
161 new->key = strdup(key);
162 if (!dup)
163 new->groups = tmp;
164 else
165 new->groups = (struct grouplist *)&dummy;
166 new->next = table[i];
167 table[i] = new;
168
169 return;
170 }
171