1 /* $OpenBSD: hash.c,v 1.9 2004/05/10 15:30:47 deraadt Exp $ */
3 /* Routines for manipulating hash tables... */
6 * Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of The Internet Software Consortium nor the names
19 * of its contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
23 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
24 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26 * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
27 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
29 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
30 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
31 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
32 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
33 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * This software has been written for the Internet Software Consortium
37 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
38 * Enterprises. To learn more about the Internet Software Consortium,
39 * see ``http://www.vix.com/isc''. To learn more about Vixie
40 * Enterprises, see ``http://www.vix.com''.
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
48 static int do_hash(unsigned char *, int, int);
53 struct hash_table *rv = new_hash_table(DEFAULT_HASH_SIZE);
57 memset(&rv->buckets[0], 0,
58 DEFAULT_HASH_SIZE * sizeof(struct hash_bucket *));
63 do_hash(unsigned char *name, int len, int size)
65 unsigned char *s = name;
66 int accum = 0, i = len;
69 /* Add the character in... */
71 /* Add carry back in... */
73 accum = (accum & 255) + (accum >> 8);
75 return (accum % size);
78 void add_hash(struct hash_table *table, unsigned char *name, int len,
79 unsigned char *pointer)
81 struct hash_bucket *bp;
87 len = strlen((char *)name);
89 hashno = do_hash(name, len, table->hash_count);
90 bp = new_hash_bucket();
93 warning("Can't add %s to hash table.", name);
98 bp->next = table->buckets[hashno];
100 table->buckets[hashno] = bp;
104 hash_lookup(struct hash_table *table, unsigned char *name, int len)
106 struct hash_bucket *bp;
113 len = strlen((char *)name);
115 hashno = do_hash(name, len, table->hash_count);
117 for (bp = table->buckets[hashno]; bp; bp = bp->next)
118 if (len == bp->len && !memcmp(bp->name, name, len))