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