1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1995 5 * Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Bill Paul. 18 * 4. Neither the name of the author nor the names of any co-contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 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[] = 43 "$FreeBSD$"; 44 #endif /* not lint */ 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(const void *keyarg, size_t len) 57 { 58 const u_char *key; 59 size_t loop; 60 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(char *key) 106 { 107 108 if (key == NULL) 109 return (-1); 110 return(hash((void *)key, strlen(key)) & HASH_MASK); 111 } 112 113 /* Find an entry in the hash table (may be hanging off a linked list). */ 114 struct grouplist *lookup(struct member_entry *table[], char *key) 115 { 116 struct member_entry *cur; 117 118 cur = table[hashkey(key)]; 119 120 while (cur) { 121 if (!strcmp(cur->key, key)) 122 return(cur->groups); 123 cur = cur->next; 124 } 125 126 return(NULL); 127 } 128 129 struct grouplist dummy = { 99999, NULL }; 130 131 /* 132 * Store a group member entry and/or update its grouplist. 133 */ 134 void mstore (struct member_entry *table[], char *key, int gid, int dup) 135 { 136 struct member_entry *cur, *new; 137 struct grouplist *tmp; 138 u_int32_t i; 139 140 i = hashkey(key); 141 cur = table[i]; 142 143 if (!dup) { 144 tmp = (struct grouplist *)malloc(sizeof(struct grouplist)); 145 tmp->groupid = gid; 146 tmp->next = NULL; 147 } 148 149 /* Check if all we have to do is insert a new groupname. */ 150 while (cur) { 151 if (!dup && !strcmp(cur->key, key)) { 152 tmp->next = cur->groups; 153 cur->groups = tmp; 154 return; 155 } 156 cur = cur->next; 157 } 158 159 /* Didn't find a match -- add the whole mess to the table. */ 160 new = (struct member_entry *)malloc(sizeof(struct member_entry)); 161 new->key = strdup(key); 162 if (!dup) 163 new->groups = tmp; 164 else 165 new->groups = (struct grouplist *)&dummy; 166 new->next = table[i]; 167 table[i] = new; 168 169 return; 170 } 171