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/*
* Copyright (c) 1995
* Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Bill Paul.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: hash.c,v 1.3 1996/06/24 22:48:50 wpaul Exp $
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include "hash.h"
#ifndef lint
static const char rcsid[] = "$Id: hash.c,v 1.3 1996/06/24 22:48:50 wpaul Exp $";
#endif
/*
* This hash function is stolen directly from the
* Berkeley DB package. It already exists inside libc, but
* it's declared static which prevents us from calling it
* from here.
*/
/*
* OZ's original sdbm hash
*/
u_int32_t
hash(keyarg, len)
const void *keyarg;
register size_t len;
{
register const u_char *key;
register size_t loop;
register u_int32_t h;
#define HASHC h = *key++ + 65599 * h
h = 0;
key = keyarg;
if (len > 0) {
loop = (len + 8 - 1) >> 3;
switch (len & (8 - 1)) {
case 0:
do {
HASHC;
/* FALLTHROUGH */
case 7:
HASHC;
/* FALLTHROUGH */
case 6:
HASHC;
/* FALLTHROUGH */
case 5:
HASHC;
/* FALLTHROUGH */
case 4:
HASHC;
/* FALLTHROUGH */
case 3:
HASHC;
/* FALLTHROUGH */
case 2:
HASHC;
/* FALLTHROUGH */
case 1:
HASHC;
} while (--loop);
}
}
return (h);
}
/*
* Generate a hash value for a given key (character string).
* We mask off all but the lower 8 bits since our table array
* can only hole 256 elements.
*/
u_int32_t hashkey(key)
char *key;
{
if (key == NULL)
return (-1);
return(hash((void *)key, strlen(key)) & HASH_MASK);
}
/* Find an entry in the hash table (may be hanging off a linked list). */
struct grouplist *lookup(table, key)
struct member_entry *table[];
char *key;
{
struct member_entry *cur;
cur = table[hashkey(key)];
while (cur) {
if (!strcmp(cur->key, key))
return(cur->groups);
cur = cur->next;
}
return(NULL);
}
struct grouplist dummy = { 99999, NULL };
/*
* Store an group member entry and/or update its grouplist.
*/
void mstore (table, key, gid, dup)
struct member_entry *table[];
char *key;
int gid;
int dup;
{
struct member_entry *cur, *new;
struct grouplist *tmp;
u_int32_t i;
i = hashkey(key);
cur = table[i];
if (!dup) {
tmp = (struct grouplist *)malloc(sizeof(struct grouplist));
tmp->groupid = gid;
tmp->next = NULL;
}
/* Check if all we have to do is insert a new groupname. */
while (cur) {
if (!dup && !strcmp(cur->key, key)) {
tmp->next = cur->groups;
cur->groups = tmp;
return;
}
cur = cur->next;
}
/* Didn't find a match -- add the whole mess to the table. */
new = (struct member_entry *)malloc(sizeof(struct member_entry));
new->key = strdup(key);
if (!dup)
new->groups = tmp;
else
new->groups = (struct grouplist *)&dummy;
new->next = table[i];
table[i] = new;
return;
}
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