1/* crypto/lhash/lhash.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59/* Code for dynamic hash table routines
60 * Author - Eric Young v 2.0
61 *
62 * 2.2 eay - added #include "crypto.h" so the memory leak checking code is
63 *	     present. eay 18-Jun-98
64 *
65 * 2.1 eay - Added an 'error in last operation' flag. eay 6-May-98
66 *
67 * 2.0 eay - Fixed a bug that occurred when using lh_delete
68 *	     from inside lh_doall().  As entries were deleted,
69 *	     the 'table' was 'contract()ed', making some entries
70 *	     jump from the end of the table to the start, there by
71 *	     skipping the lh_doall() processing. eay - 4/12/95
72 *
73 * 1.9 eay - Fixed a memory leak in lh_free, the LHASH_NODEs
74 *	     were not being free()ed. 21/11/95
75 *
76 * 1.8 eay - Put the stats routines into a separate file, lh_stats.c
77 *	     19/09/95
78 *
79 * 1.7 eay - Removed the fputs() for realloc failures - the code
80 *           should silently tolerate them.  I have also fixed things
81 *           lint complained about 04/05/95
82 *
83 * 1.6 eay - Fixed an invalid pointers in contract/expand 27/07/92
84 *
85 * 1.5 eay - Fixed a misuse of realloc in expand 02/03/1992
86 *
87 * 1.4 eay - Fixed lh_doall so the function can call lh_delete 28/05/91
88 *
89 * 1.3 eay - Fixed a few lint problems 19/3/1991
90 *
91 * 1.2 eay - Fixed lh_doall problem 13/3/1991
92 *
93 * 1.1 eay - Added lh_doall
94 *
95 * 1.0 eay - First version
96 */
97#include <stdio.h>
98#include <string.h>
99#include <stdlib.h>
100#include <openssl/crypto.h>
101#include <openssl/lhash.h>
102
103const char *lh_version="lhash" OPENSSL_VERSION_PTEXT;
104
105#undef MIN_NODES
106#define MIN_NODES	16
107#define UP_LOAD		(2*LH_LOAD_MULT) /* load times 256  (default 2) */
108#define DOWN_LOAD	(LH_LOAD_MULT)   /* load times 256  (default 1) */
109
110static void expand(LHASH *lh);
111static void contract(LHASH *lh);
112static LHASH_NODE **getrn(LHASH *lh, const void *data, unsigned long *rhash);
113
114LHASH *lh_new(LHASH_HASH_FN_TYPE h, LHASH_COMP_FN_TYPE c)
115	{
116	LHASH *ret;
117	int i;
118
119	if ((ret=(LHASH *)OPENSSL_malloc(sizeof(LHASH))) == NULL)
120		goto err0;
121	if ((ret->b=(LHASH_NODE **)OPENSSL_malloc(sizeof(LHASH_NODE *)*MIN_NODES)) == NULL)
122		goto err1;
123	for (i=0; i<MIN_NODES; i++)
124		ret->b[i]=NULL;
125	ret->comp=((c == NULL)?(LHASH_COMP_FN_TYPE)strcmp:c);
126	ret->hash=((h == NULL)?(LHASH_HASH_FN_TYPE)lh_strhash:h);
127	ret->num_nodes=MIN_NODES/2;
128	ret->num_alloc_nodes=MIN_NODES;
129	ret->p=0;
130	ret->pmax=MIN_NODES/2;
131	ret->up_load=UP_LOAD;
132	ret->down_load=DOWN_LOAD;
133	ret->num_items=0;
134
135	ret->num_expands=0;
136	ret->num_expand_reallocs=0;
137	ret->num_contracts=0;
138	ret->num_contract_reallocs=0;
139	ret->num_hash_calls=0;
140	ret->num_comp_calls=0;
141	ret->num_insert=0;
142	ret->num_replace=0;
143	ret->num_delete=0;
144	ret->num_no_delete=0;
145	ret->num_retrieve=0;
146	ret->num_retrieve_miss=0;
147	ret->num_hash_comps=0;
148
149	ret->error=0;
150	return(ret);
151err1:
152	OPENSSL_free(ret);
153err0:
154	return(NULL);
155	}
156
157void lh_free(LHASH *lh)
158	{
159	unsigned int i;
160	LHASH_NODE *n,*nn;
161
162	if (lh == NULL)
163	    return;
164
165	for (i=0; i<lh->num_nodes; i++)
166		{
167		n=lh->b[i];
168		while (n != NULL)
169			{
170			nn=n->next;
171			OPENSSL_free(n);
172			n=nn;
173			}
174		}
175	OPENSSL_free(lh->b);
176	OPENSSL_free(lh);
177	}
178
179void *lh_insert(LHASH *lh, const void *data)
180	{
181	unsigned long hash;
182	LHASH_NODE *nn,**rn;
183	const void *ret;
184
185	lh->error=0;
186	if (lh->up_load <= (lh->num_items*LH_LOAD_MULT/lh->num_nodes))
187		expand(lh);
188
189	rn=getrn(lh,data,&hash);
190
191	if (*rn == NULL)
192		{
193		if ((nn=(LHASH_NODE *)OPENSSL_malloc(sizeof(LHASH_NODE))) == NULL)
194			{
195			lh->error++;
196			return(NULL);
197			}
198		nn->data=data;
199		nn->next=NULL;
200#ifndef OPENSSL_NO_HASH_COMP
201		nn->hash=hash;
202#endif
203		*rn=nn;
204		ret=NULL;
205		lh->num_insert++;
206		lh->num_items++;
207		}
208	else /* replace same key */
209		{
210		ret= (*rn)->data;
211		(*rn)->data=data;
212		lh->num_replace++;
213		}
214	return((void *)ret);
215	}
216
217void *lh_delete(LHASH *lh, const void *data)
218	{
219	unsigned long hash;
220	LHASH_NODE *nn,**rn;
221	const void *ret;
222
223	lh->error=0;
224	rn=getrn(lh,data,&hash);
225
226	if (*rn == NULL)
227		{
228		lh->num_no_delete++;
229		return(NULL);
230		}
231	else
232		{
233		nn= *rn;
234		*rn=nn->next;
235		ret=nn->data;
236		OPENSSL_free(nn);
237		lh->num_delete++;
238		}
239
240	lh->num_items--;
241	if ((lh->num_nodes > MIN_NODES) &&
242		(lh->down_load >= (lh->num_items*LH_LOAD_MULT/lh->num_nodes)))
243		contract(lh);
244
245	return((void *)ret);
246	}
247
248void *lh_retrieve(LHASH *lh, const void *data)
249	{
250	unsigned long hash;
251	LHASH_NODE **rn;
252	const void *ret;
253
254	lh->error=0;
255	rn=getrn(lh,data,&hash);
256
257	if (*rn == NULL)
258		{
259		lh->num_retrieve_miss++;
260		return(NULL);
261		}
262	else
263		{
264		ret= (*rn)->data;
265		lh->num_retrieve++;
266		}
267	return((void *)ret);
268	}
269
270static void doall_util_fn(LHASH *lh, int use_arg, LHASH_DOALL_FN_TYPE func,
271			  LHASH_DOALL_ARG_FN_TYPE func_arg, void *arg)
272	{
273	int i;
274	LHASH_NODE *a,*n;
275
276	/* reverse the order so we search from 'top to bottom'
277	 * We were having memory leaks otherwise */
278	for (i=lh->num_nodes-1; i>=0; i--)
279		{
280		a=lh->b[i];
281		while (a != NULL)
282			{
283			/* 28/05/91 - eay - n added so items can be deleted
284			 * via lh_doall */
285			n=a->next;
286			if(use_arg)
287				func_arg(a->data,arg);
288			else
289				func(a->data);
290			a=n;
291			}
292		}
293	}
294
295void lh_doall(LHASH *lh, LHASH_DOALL_FN_TYPE func)
296	{
297	doall_util_fn(lh, 0, func, (LHASH_DOALL_ARG_FN_TYPE)0, NULL);
298	}
299
300void lh_doall_arg(LHASH *lh, LHASH_DOALL_ARG_FN_TYPE func, void *arg)
301	{
302	doall_util_fn(lh, 1, (LHASH_DOALL_FN_TYPE)0, func, arg);
303	}
304
305static void expand(LHASH *lh)
306	{
307	LHASH_NODE **n,**n1,**n2,*np;
308	unsigned int p,i,j;
309	unsigned long hash,nni;
310
311	lh->num_nodes++;
312	lh->num_expands++;
313	p=(int)lh->p++;
314	n1= &(lh->b[p]);
315	n2= &(lh->b[p+(int)lh->pmax]);
316	*n2=NULL;        /* 27/07/92 - eay - undefined pointer bug */
317	nni=lh->num_alloc_nodes;
318
319	for (np= *n1; np != NULL; )
320		{
321#ifndef OPENSSL_NO_HASH_COMP
322		hash=np->hash;
323#else
324		hash=lh->hash(np->data);
325		lh->num_hash_calls++;
326#endif
327		if ((hash%nni) != p)
328			{ /* move it */
329			*n1= (*n1)->next;
330			np->next= *n2;
331			*n2=np;
332			}
333		else
334			n1= &((*n1)->next);
335		np= *n1;
336		}
337
338	if ((lh->p) >= lh->pmax)
339		{
340		j=(int)lh->num_alloc_nodes*2;
341		n=(LHASH_NODE **)OPENSSL_realloc(lh->b,
342			(unsigned int)sizeof(LHASH_NODE *)*j);
343		if (n == NULL)
344			{
345/*			fputs("realloc error in lhash",stderr); */
346			lh->error++;
347			lh->p=0;
348			return;
349			}
350		/* else */
351		for (i=(int)lh->num_alloc_nodes; i<j; i++)/* 26/02/92 eay */
352			n[i]=NULL;			  /* 02/03/92 eay */
353		lh->pmax=lh->num_alloc_nodes;
354		lh->num_alloc_nodes=j;
355		lh->num_expand_reallocs++;
356		lh->p=0;
357		lh->b=n;
358		}
359	}
360
361static void contract(LHASH *lh)
362	{
363	LHASH_NODE **n,*n1,*np;
364
365	np=lh->b[lh->p+lh->pmax-1];
366	lh->b[lh->p+lh->pmax-1]=NULL; /* 24/07-92 - eay - weird but :-( */
367	if (lh->p == 0)
368		{
369		n=(LHASH_NODE **)OPENSSL_realloc(lh->b,
370			(unsigned int)(sizeof(LHASH_NODE *)*lh->pmax));
371		if (n == NULL)
372			{
373/*			fputs("realloc error in lhash",stderr); */
374			lh->error++;
375			return;
376			}
377		lh->num_contract_reallocs++;
378		lh->num_alloc_nodes/=2;
379		lh->pmax/=2;
380		lh->p=lh->pmax-1;
381		lh->b=n;
382		}
383	else
384		lh->p--;
385
386	lh->num_nodes--;
387	lh->num_contracts++;
388
389	n1=lh->b[(int)lh->p];
390	if (n1 == NULL)
391		lh->b[(int)lh->p]=np;
392	else
393		{
394		while (n1->next != NULL)
395			n1=n1->next;
396		n1->next=np;
397		}
398	}
399
400static LHASH_NODE **getrn(LHASH *lh, const void *data, unsigned long *rhash)
401	{
402	LHASH_NODE **ret,*n1;
403	unsigned long hash,nn;
404	int (*cf)();
405
406	hash=(*(lh->hash))(data);
407	lh->num_hash_calls++;
408	*rhash=hash;
409
410	nn=hash%lh->pmax;
411	if (nn < lh->p)
412		nn=hash%lh->num_alloc_nodes;
413
414	cf=lh->comp;
415	ret= &(lh->b[(int)nn]);
416	for (n1= *ret; n1 != NULL; n1=n1->next)
417		{
418#ifndef OPENSSL_NO_HASH_COMP
419		lh->num_hash_comps++;
420		if (n1->hash != hash)
421			{
422			ret= &(n1->next);
423			continue;
424			}
425#endif
426		lh->num_comp_calls++;
427		if(cf(n1->data,data) == 0)
428			break;
429		ret= &(n1->next);
430		}
431	return(ret);
432	}
433
434/* The following hash seems to work very well on normal text strings
435 * no collisions on /usr/dict/words and it distributes on %2^n quite
436 * well, not as good as MD5, but still good.
437 */
438unsigned long lh_strhash(const char *c)
439	{
440	unsigned long ret=0;
441	long n;
442	unsigned long v;
443	int r;
444
445	if ((c == NULL) || (*c == '\0'))
446		return(ret);
447/*
448	unsigned char b[16];
449	MD5(c,strlen(c),b);
450	return(b[0]|(b[1]<<8)|(b[2]<<16)|(b[3]<<24));
451*/
452
453	n=0x100;
454	while (*c)
455		{
456		v=n|(*c);
457		n+=0x100;
458		r= (int)((v>>2)^v)&0x0f;
459		ret=(ret<<r)|(ret>>(32-r));
460		ret&=0xFFFFFFFFL;
461		ret^=v*v;
462		c++;
463		}
464	return((ret>>16)^ret);
465	}
466
467unsigned long lh_num_items(const LHASH *lh)
468	{
469	return lh ? lh->num_items : 0;
470	}
471