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 } 178