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 "$FreeBSD$"; 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(const void *keyarg, size_t len) 55 { 56 const u_char *key; 57 size_t loop; 58 u_int32_t h; 59 60 #define HASHC h = *key++ + 65599 * h 61 62 h = 0; 63 key = keyarg; 64 if (len > 0) { 65 loop = (len + 8 - 1) >> 3; 66 67 switch (len & (8 - 1)) { 68 case 0: 69 do { 70 HASHC; 71 /* FALLTHROUGH */ 72 case 7: 73 HASHC; 74 /* FALLTHROUGH */ 75 case 6: 76 HASHC; 77 /* FALLTHROUGH */ 78 case 5: 79 HASHC; 80 /* FALLTHROUGH */ 81 case 4: 82 HASHC; 83 /* FALLTHROUGH */ 84 case 3: 85 HASHC; 86 /* FALLTHROUGH */ 87 case 2: 88 HASHC; 89 /* FALLTHROUGH */ 90 case 1: 91 HASHC; 92 } while (--loop); 93 } 94 } 95 return (h); 96 } 97 98 /* 99 * Generate a hash value for a given key (character string). 100 * We mask off all but the lower 8 bits since our table array 101 * can only hole 256 elements. 102 */ 103 u_int32_t hashkey(char *key) 104 { 105 106 if (key == NULL) 107 return (-1); 108 return(hash((void *)key, strlen(key)) & HASH_MASK); 109 } 110 111 /* Find an entry in the hash table (may be hanging off a linked list). */ 112 struct grouplist *lookup(struct member_entry *table[], char *key) 113 { 114 struct member_entry *cur; 115 116 cur = table[hashkey(key)]; 117 118 while (cur) { 119 if (!strcmp(cur->key, key)) 120 return(cur->groups); 121 cur = cur->next; 122 } 123 124 return(NULL); 125 } 126 127 struct grouplist dummy = { 99999, NULL }; 128 129 /* 130 * Store a group member entry and/or update its grouplist. 131 */ 132 void mstore (struct member_entry *table[], char *key, int gid, int dup) 133 { 134 struct member_entry *cur, *new; 135 struct grouplist *tmp; 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 } 169