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 * $Id$ 33 */ 34 35 #include <stdio.h> 36 #include <stdlib.h> 37 #include <string.h> 38 #include <sys/types.h> 39 #include "hash.h" 40 41 #ifndef lint 42 static const char rcsid[] = "$Id$"; 43 #endif 44 45 46 /* 47 * This hash function is stolen directly from the 48 * Berkeley DB package. It already exists inside libc, but 49 * it's declared static which prevents us from calling it 50 * from here. 51 */ 52 /* 53 * OZ's original sdbm hash 54 */ 55 u_int32_t 56 hash(keyarg, len) 57 const void *keyarg; 58 register size_t len; 59 { 60 register const u_char *key; 61 register size_t loop; 62 register u_int32_t h; 63 64 #define HASHC h = *key++ + 65599 * h 65 66 h = 0; 67 key = keyarg; 68 if (len > 0) { 69 loop = (len + 8 - 1) >> 3; 70 71 switch (len & (8 - 1)) { 72 case 0: 73 do { 74 HASHC; 75 /* FALLTHROUGH */ 76 case 7: 77 HASHC; 78 /* FALLTHROUGH */ 79 case 6: 80 HASHC; 81 /* FALLTHROUGH */ 82 case 5: 83 HASHC; 84 /* FALLTHROUGH */ 85 case 4: 86 HASHC; 87 /* FALLTHROUGH */ 88 case 3: 89 HASHC; 90 /* FALLTHROUGH */ 91 case 2: 92 HASHC; 93 /* FALLTHROUGH */ 94 case 1: 95 HASHC; 96 } while (--loop); 97 } 98 } 99 return (h); 100 } 101 102 /* 103 * Generate a hash value for a given key (character string). 104 * We mask off all but the lower 8 bits since our table array 105 * can only hole 256 elements. 106 */ 107 u_int32_t hashkey(key) 108 char *key; 109 { 110 111 if (key == NULL) 112 return (-1); 113 return(hash((void *)key, strlen(key)) & HASH_MASK); 114 } 115 116 /* Find an entry in the hash table (may be hanging off a linked list). */ 117 struct grouplist *lookup(table, key) 118 struct member_entry *table[]; 119 char *key; 120 { 121 struct member_entry *cur; 122 123 cur = table[hashkey(key)]; 124 125 while (cur) { 126 if (!strcmp(cur->key, key)) 127 return(cur->groups); 128 cur = cur->next; 129 } 130 131 return(NULL); 132 } 133 134 struct grouplist dummy = { 99999, NULL }; 135 136 /* 137 * Store an group member entry and/or update its grouplist. 138 */ 139 void mstore (table, key, gid, dup) 140 struct member_entry *table[]; 141 char *key; 142 int gid; 143 int dup; 144 { 145 struct member_entry *cur, *new; 146 struct grouplist *tmp; 147 u_int32_t i; 148 149 i = hashkey(key); 150 cur = table[i]; 151 152 if (!dup) { 153 tmp = (struct grouplist *)malloc(sizeof(struct grouplist)); 154 tmp->groupid = gid; 155 tmp->next = NULL; 156 } 157 158 /* Check if all we have to do is insert a new groupname. */ 159 while (cur) { 160 if (!dup && !strcmp(cur->key, key)) { 161 tmp->next = cur->groups; 162 cur->groups = tmp; 163 return; 164 } 165 cur = cur->next; 166 } 167 168 /* Didn't find a match -- add the whole mess to the table. */ 169 new = (struct member_entry *)malloc(sizeof(struct member_entry)); 170 new->key = strdup(key); 171 if (!dup) 172 new->groups = tmp; 173 else 174 new->groups = (struct grouplist *)&dummy; 175 new->next = table[i]; 176 table[i] = new; 177 178 return; 179 } 180