| 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 |
| 40 | static const char rcsid[] = |
| 41 | "$FreeBSD: src/libexec/mknetid/hash.c,v 1.5 1999/08/28 00:09:40 peter Exp $"; |
| 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 | */ |
| 53 | u_int32_t |
| 54 | hash(keyarg, len) |
| 55 | const void *keyarg; |
| 56 | register size_t len; |
| 57 | { |
| 58 | register const u_char *key; |
| 59 | register size_t loop; |
| 60 | register 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 | */ |
| 105 | u_int32_t hashkey(key) |
| 106 | char *key; |
| 107 | { |
| 108 | |
| 109 | if (key == NULL) |
| 110 | return (-1); |
| 111 | return(hash((void *)key, strlen(key)) & HASH_MASK); |
| 112 | } |
| 113 | |
| 114 | /* Find an entry in the hash table (may be hanging off a linked list). */ |
| 115 | struct grouplist *lookup(table, key) |
| 116 | struct member_entry *table[]; |
| 117 | char *key; |
| 118 | { |
| 119 | struct member_entry *cur; |
| 120 | |
| 121 | cur = table[hashkey(key)]; |
| 122 | |
| 123 | while (cur) { |
| 124 | if (!strcmp(cur->key, key)) |
| 125 | return(cur->groups); |
| 126 | cur = cur->next; |
| 127 | } |
| 128 | |
| 129 | return(NULL); |
| 130 | } |
| 131 | |
| 132 | struct grouplist dummy = { 99999, NULL }; |
| 133 | |
| 134 | /* |
| 135 | * Store an group member entry and/or update its grouplist. |
| 136 | */ |
| 137 | void mstore (table, key, gid, dup) |
| 138 | struct member_entry *table[]; |
| 139 | char *key; |
| 140 | int gid; |
| 141 | int dup; |
| 142 | { |
| 143 | struct member_entry *cur, *new; |
| 144 | struct grouplist *tmp; |
| 145 | u_int32_t i; |
| 146 | |
| 147 | i = hashkey(key); |
| 148 | cur = table[i]; |
| 149 | |
| 150 | if (!dup) { |
| 151 | tmp = (struct grouplist *)malloc(sizeof(struct grouplist)); |
| 152 | tmp->groupid = gid; |
| 153 | tmp->next = NULL; |
| 154 | } |
| 155 | |
| 156 | /* Check if all we have to do is insert a new groupname. */ |
| 157 | while (cur) { |
| 158 | if (!dup && !strcmp(cur->key, key)) { |
| 159 | tmp->next = cur->groups; |
| 160 | cur->groups = tmp; |
| 161 | return; |
| 162 | } |
| 163 | cur = cur->next; |
| 164 | } |
| 165 | |
| 166 | /* Didn't find a match -- add the whole mess to the table. */ |
| 167 | new = (struct member_entry *)malloc(sizeof(struct member_entry)); |
| 168 | new->key = strdup(key); |
| 169 | if (!dup) |
| 170 | new->groups = tmp; |
| 171 | else |
| 172 | new->groups = (struct grouplist *)&dummy; |
| 173 | new->next = table[i]; |
| 174 | table[i] = new; |
| 175 | |
| 176 | return; |
| 177 | } |