1 |
|
|
/* $OpenBSD: hash.c,v 1.8 2017/02/13 19:13:14 krw Exp $ */ |
2 |
|
|
|
3 |
|
|
/* Routines for manipulating hash tables... */ |
4 |
|
|
|
5 |
|
|
/* |
6 |
|
|
* Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium. |
7 |
|
|
* All rights reserved. |
8 |
|
|
* |
9 |
|
|
* Redistribution and use in source and binary forms, with or without |
10 |
|
|
* modification, are permitted provided that the following conditions |
11 |
|
|
* are met: |
12 |
|
|
* |
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. |
21 |
|
|
* |
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 |
34 |
|
|
* SUCH DAMAGE. |
35 |
|
|
* |
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''. |
41 |
|
|
*/ |
42 |
|
|
|
43 |
|
|
#include <sys/types.h> |
44 |
|
|
#include <sys/socket.h> |
45 |
|
|
|
46 |
|
|
#include <net/if.h> |
47 |
|
|
|
48 |
|
|
#include <netinet/in.h> |
49 |
|
|
|
50 |
|
|
#include <stdio.h> |
51 |
|
|
#include <stdlib.h> |
52 |
|
|
#include <string.h> |
53 |
|
|
|
54 |
|
|
#include "dhcp.h" |
55 |
|
|
#include "tree.h" |
56 |
|
|
#include "dhcpd.h" |
57 |
|
|
#include "log.h" |
58 |
|
|
|
59 |
|
|
static int do_hash(unsigned char *, int, int); |
60 |
|
|
|
61 |
|
|
struct hash_table * |
62 |
|
|
new_hash(void) |
63 |
|
|
{ |
64 |
|
|
struct hash_table *rv; |
65 |
|
|
|
66 |
|
|
rv = calloc(1, sizeof(struct hash_table)); |
67 |
|
|
if (!rv) |
68 |
|
|
log_warnx("No memory for new hash."); |
69 |
|
|
else |
70 |
|
|
rv->hash_count = DEFAULT_HASH_SIZE; |
71 |
|
|
|
72 |
|
|
return (rv); |
73 |
|
|
} |
74 |
|
|
|
75 |
|
|
static int |
76 |
|
|
do_hash(unsigned char *name, int len, int size) |
77 |
|
|
{ |
78 |
|
|
int accum = 0; |
79 |
|
|
unsigned char *s = name; |
80 |
|
|
int i = len; |
81 |
|
|
|
82 |
|
|
while (i--) { |
83 |
|
|
/* Add the character in... */ |
84 |
|
|
accum += *s++; |
85 |
|
|
/* Add carry back in... */ |
86 |
|
|
while (accum > 255) |
87 |
|
|
accum = (accum & 255) + (accum >> 8); |
88 |
|
|
} |
89 |
|
|
return (accum % size); |
90 |
|
|
} |
91 |
|
|
|
92 |
|
|
void add_hash(struct hash_table *table, unsigned char *name, int len, |
93 |
|
|
unsigned char *pointer) |
94 |
|
|
{ |
95 |
|
|
int hashno; |
96 |
|
|
struct hash_bucket *bp; |
97 |
|
|
|
98 |
|
|
if (!table) |
99 |
|
|
return; |
100 |
|
|
if (!len) |
101 |
|
|
len = strlen((char *)name); |
102 |
|
|
|
103 |
|
|
hashno = do_hash(name, len, table->hash_count); |
104 |
|
|
bp = calloc(1, sizeof(struct hash_bucket)); |
105 |
|
|
if (!bp) { |
106 |
|
|
log_warnx("Can't add %s to hash table.", name); |
107 |
|
|
return; |
108 |
|
|
} |
109 |
|
|
bp->name = name; |
110 |
|
|
bp->value = pointer; |
111 |
|
|
bp->next = table->buckets[hashno]; |
112 |
|
|
bp->len = len; |
113 |
|
|
table->buckets[hashno] = bp; |
114 |
|
|
} |
115 |
|
|
|
116 |
|
|
void |
117 |
|
|
delete_hash_entry(struct hash_table *table, unsigned char *name, int len) |
118 |
|
|
{ |
119 |
|
|
int hashno; |
120 |
|
|
struct hash_bucket *bp, *pbp = NULL; |
121 |
|
|
|
122 |
|
|
if (!table) |
123 |
|
|
return; |
124 |
|
|
if (!len) |
125 |
|
|
len = strlen((char *)name); |
126 |
|
|
|
127 |
|
|
hashno = do_hash(name, len, table->hash_count); |
128 |
|
|
|
129 |
|
|
/* |
130 |
|
|
* Go through the list looking for an entry that matches; if we |
131 |
|
|
* find it, delete it. |
132 |
|
|
*/ |
133 |
|
|
for (bp = table->buckets[hashno]; bp; bp = bp->next) { |
134 |
|
|
if ((!bp->len && |
135 |
|
|
!strcmp((char *)bp->name, (char *)name)) || |
136 |
|
|
(bp->len == len && !memcmp(bp->name, name, len))) { |
137 |
|
|
if (pbp) |
138 |
|
|
pbp->next = bp->next; |
139 |
|
|
else |
140 |
|
|
table->buckets[hashno] = bp->next; |
141 |
|
|
free(bp); |
142 |
|
|
break; |
143 |
|
|
} |
144 |
|
|
pbp = bp; /* jwg, 9/6/96 - nice catch! */ |
145 |
|
|
} |
146 |
|
|
} |
147 |
|
|
|
148 |
|
|
unsigned char * |
149 |
|
|
hash_lookup(struct hash_table *table, unsigned char *name, int len) |
150 |
|
|
{ |
151 |
|
|
int hashno; |
152 |
|
|
struct hash_bucket *bp; |
153 |
|
|
|
154 |
|
|
if (!table) |
155 |
|
|
return (NULL); |
156 |
|
|
|
157 |
|
|
if (!len) |
158 |
|
|
len = strlen((char *)name); |
159 |
|
|
|
160 |
|
|
hashno = do_hash(name, len, table->hash_count); |
161 |
|
|
|
162 |
|
|
for (bp = table->buckets[hashno]; bp; bp = bp->next) |
163 |
|
|
if (len == bp->len && !memcmp(bp->name, name, len)) |
164 |
|
|
return (bp->value); |
165 |
|
|
|
166 |
|
|
return (NULL); |
167 |
|
|
} |