Commit | Line | Data |
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984263bc MD |
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. | |
1de703da MD |
31 | * |
32 | * $FreeBSD: src/libexec/mknetid/hash.c,v 1.5 1999/08/28 00:09:40 peter Exp $ | |
984263bc MD |
33 | */ |
34 | ||
35 | #include <stdio.h> | |
36 | #include <stdlib.h> | |
37 | #include <string.h> | |
38 | #include <sys/types.h> | |
39 | #include "hash.h" | |
40 | ||
984263bc MD |
41 | /* |
42 | * This hash function is stolen directly from the | |
43 | * Berkeley DB package. It already exists inside libc, but | |
44 | * it's declared static which prevents us from calling it | |
45 | * from here. | |
46 | */ | |
47 | /* | |
48 | * OZ's original sdbm hash | |
49 | */ | |
06a0ed23 SW |
50 | static u_int32_t |
51 | hash(const void *keyarg, size_t len) | |
984263bc | 52 | { |
06a0ed23 SW |
53 | const u_char *key; |
54 | size_t loop; | |
55 | u_int32_t h; | |
984263bc MD |
56 | |
57 | #define HASHC h = *key++ + 65599 * h | |
58 | ||
59 | h = 0; | |
60 | key = keyarg; | |
61 | if (len > 0) { | |
62 | loop = (len + 8 - 1) >> 3; | |
63 | ||
64 | switch (len & (8 - 1)) { | |
65 | case 0: | |
66 | do { | |
67 | HASHC; | |
68 | /* FALLTHROUGH */ | |
69 | case 7: | |
70 | HASHC; | |
71 | /* FALLTHROUGH */ | |
72 | case 6: | |
73 | HASHC; | |
74 | /* FALLTHROUGH */ | |
75 | case 5: | |
76 | HASHC; | |
77 | /* FALLTHROUGH */ | |
78 | case 4: | |
79 | HASHC; | |
80 | /* FALLTHROUGH */ | |
81 | case 3: | |
82 | HASHC; | |
83 | /* FALLTHROUGH */ | |
84 | case 2: | |
85 | HASHC; | |
86 | /* FALLTHROUGH */ | |
87 | case 1: | |
88 | HASHC; | |
89 | } while (--loop); | |
90 | } | |
91 | } | |
92 | return (h); | |
93 | } | |
94 | ||
95 | /* | |
96 | * Generate a hash value for a given key (character string). | |
97 | * We mask off all but the lower 8 bits since our table array | |
98 | * can only hole 256 elements. | |
99 | */ | |
06a0ed23 SW |
100 | static u_int32_t |
101 | hashkey(char *key) | |
984263bc MD |
102 | { |
103 | ||
104 | if (key == NULL) | |
105 | return (-1); | |
4e1af74f | 106 | return(hash(key, strlen(key)) & HASH_MASK); |
984263bc MD |
107 | } |
108 | ||
109 | /* Find an entry in the hash table (may be hanging off a linked list). */ | |
06a0ed23 SW |
110 | struct grouplist * |
111 | lookup(struct member_entry *table[], char *key) | |
984263bc MD |
112 | { |
113 | struct member_entry *cur; | |
114 | ||
115 | cur = table[hashkey(key)]; | |
116 | ||
117 | while (cur) { | |
118 | if (!strcmp(cur->key, key)) | |
119 | return(cur->groups); | |
120 | cur = cur->next; | |
121 | } | |
122 | ||
123 | return(NULL); | |
124 | } | |
125 | ||
126 | struct grouplist dummy = { 99999, NULL }; | |
127 | ||
128 | /* | |
129 | * Store an group member entry and/or update its grouplist. | |
130 | */ | |
06a0ed23 SW |
131 | void |
132 | mstore(struct member_entry *table[], char *key, int gid, int dup) | |
984263bc MD |
133 | { |
134 | struct member_entry *cur, *new; | |
06a0ed23 | 135 | struct grouplist *tmp = NULL; |
984263bc MD |
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 | } |