1/*
2 * Copyright (c) 2000-2001,2011,2014 Apple Inc. All Rights Reserved.
3 *
4 * The contents of this file constitute Original Code as defined in and are
5 * subject to the Apple Public Source License Version 1.2 (the 'License').
6 * You may not use this file except in compliance with the License. Please obtain
7 * a copy of the License at http://www.apple.com/publicsource and read it before
8 * using this file.
9 *
10 * This Original Code and all software distributed under the License are
11 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
12 * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
13 * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
14 * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
15 * specific language governing rights and limitations under the License.
16 */
17
18
19/* crypto/lhash/lhash.c */
20/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
21 * All rights reserved.
22 *
23 * This package is an SSL implementation written
24 * by Eric Young (eay@cryptsoft.com).
25 * The implementation was written so as to conform with Netscapes SSL.
26 *
27 * This library is free for commercial and non-commercial use as long as
28 * the following conditions are aheared to.  The following conditions
29 * apply to all code found in this distribution, be it the RC4, RSA,
30 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
31 * included with this distribution is covered by the same copyright terms
32 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
33 *
34 * Copyright remains Eric Young's, and as such any Copyright notices in
35 * the code are not to be removed.
36 * If this package is used in a product, Eric Young should be given attribution
37 * as the author of the parts of the library used.
38 * This can be in the form of a textual message at program startup or
39 * in documentation (online or textual) provided with the package.
40 *
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
43 * are met:
44 * 1. Redistributions of source code must retain the copyright
45 *    notice, this list of conditions and the following disclaimer.
46 * 2. Redistributions in binary form must reproduce the above copyright
47 *    notice, this list of conditions and the following disclaimer in the
48 *    documentation and/or other materials provided with the distribution.
49 * 3. All advertising materials mentioning features or use of this software
50 *    must display the following acknowledgement:
51 *    "This product includes cryptographic software written by
52 *     Eric Young (eay@cryptsoft.com)"
53 *    The word 'cryptographic' can be left out if the rouines from the library
54 *    being used are not cryptographic related :-).
55 * 4. If you include any Windows specific code (or a derivative thereof) from
56 *    the apps directory (application code) you must include an acknowledgement:
57 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
58 *
59 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
62 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69 * SUCH DAMAGE.
70 *
71 * The licence and distribution terms for any publically available version or
72 * derivative of this code cannot be changed.  i.e. this code cannot simply be
73 * copied and put under another distribution licence
74 * [including the GNU Public Licence.]
75 */
76
77/* Code for dynamic hash table routines
78 * Author - Eric Young v 2.0
79 *
80 * 2.2 eay - added #include "crypto.h" so the memory leak checking code is
81 *	     present. eay 18-Jun-98
82 *
83 * 2.1 eay - Added an 'error in last operation' flag. eay 6-May-98
84 *
85 * 2.0 eay - Fixed a bug that occurred when using lh_delete
86 *	     from inside lh_doall().  As entries were deleted,
87 *	     the 'table' was 'contract()ed', making some entries
88 *	     jump from the end of the table to the start, there by
89 *	     skipping the lh_doall() processing. eay - 4/12/95
90 *
91 * 1.9 eay - Fixed a memory leak in lh_free, the LHASH_NODEs
92 *	     were not being free()ed. 21/11/95
93 *
94 * 1.8 eay - Put the stats routines into a separate file, lh_stats.c
95 *	     19/09/95
96 *
97 * 1.7 eay - Removed the fputs() for realloc failures - the code
98 *           should silently tolerate them.  I have also fixed things
99 *           lint complained about 04/05/95
100 *
101 * 1.6 eay - Fixed an invalid pointers in contract/expand 27/07/92
102 *
103 * 1.5 eay - Fixed a misuse of realloc in expand 02/03/1992
104 *
105 * 1.4 eay - Fixed lh_doall so the function can call lh_delete 28/05/91
106 *
107 * 1.3 eay - Fixed a few lint problems 19/3/1991
108 *
109 * 1.2 eay - Fixed lh_doall problem 13/3/1991
110 *
111 * 1.1 eay - Added lh_doall
112 *
113 * 1.0 eay - First version
114 */
115#include <stdio.h>
116#include <string.h>
117#include <stdlib.h>
118#include <openssl/crypto.h>
119#include <openssl/lhash.h>
120
121const char *lh_version="lhash" OPENSSL_VERSION_PTEXT;
122
123#undef MIN_NODES
124#define MIN_NODES	16
125#define UP_LOAD		(2*LH_LOAD_MULT) /* load times 256  (default 2) */
126#define DOWN_LOAD	(LH_LOAD_MULT)   /* load times 256  (default 1) */
127
128static void expand(LHASH *lh);
129static void contract(LHASH *lh);
130static LHASH_NODE **getrn(LHASH *lh, void *data, unsigned long *rhash);
131
132LHASH *lh_new(unsigned long (*h)(), int (*c)())
133	{
134	LHASH *ret;
135	int i;
136
137	if ((ret=(LHASH *)Malloc(sizeof(LHASH))) == NULL)
138		goto err0;
139	if ((ret->b=(LHASH_NODE **)Malloc(sizeof(LHASH_NODE *)*MIN_NODES)) == NULL)
140		goto err1;
141	for (i=0; i<MIN_NODES; i++)
142		ret->b[i]=NULL;
143	ret->comp=((c == NULL)?(int (*)())strcmp:c);
144	ret->hash=((h == NULL)?(unsigned long (*)())lh_strhash:h);
145	ret->num_nodes=MIN_NODES/2;
146	ret->num_alloc_nodes=MIN_NODES;
147	ret->p=0;
148	ret->pmax=MIN_NODES/2;
149	ret->up_load=UP_LOAD;
150	ret->down_load=DOWN_LOAD;
151	ret->num_items=0;
152
153	ret->num_expands=0;
154	ret->num_expand_reallocs=0;
155	ret->num_contracts=0;
156	ret->num_contract_reallocs=0;
157	ret->num_hash_calls=0;
158	ret->num_comp_calls=0;
159	ret->num_insert=0;
160	ret->num_replace=0;
161	ret->num_delete=0;
162	ret->num_no_delete=0;
163	ret->num_retrieve=0;
164	ret->num_retrieve_miss=0;
165	ret->num_hash_comps=0;
166
167	ret->error=0;
168	return(ret);
169err1:
170	Free(ret);
171err0:
172	return(NULL);
173	}
174
175void lh_free(LHASH *lh)
176	{
177	unsigned int i;
178	LHASH_NODE *n,*nn;
179
180	if (lh == NULL)
181	    return;
182
183	for (i=0; i<lh->num_nodes; i++)
184		{
185		n=lh->b[i];
186		while (n != NULL)
187			{
188			nn=n->next;
189			Free(n);
190			n=nn;
191			}
192		}
193	Free(lh->b);
194	Free(lh);
195	}
196
197void *lh_insert(LHASH *lh, void *data)
198	{
199	unsigned long hash;
200	LHASH_NODE *nn,**rn;
201	void *ret;
202
203	lh->error=0;
204	if (lh->up_load <= (lh->num_items*LH_LOAD_MULT/lh->num_nodes))
205		expand(lh);
206
207	rn=getrn(lh,data,&hash);
208
209	if (*rn == NULL)
210		{
211		if ((nn=(LHASH_NODE *)Malloc(sizeof(LHASH_NODE))) == NULL)
212			{
213			lh->error++;
214			return(NULL);
215			}
216		nn->data=data;
217		nn->next=NULL;
218#ifndef NO_HASH_COMP
219		nn->hash=hash;
220#endif
221		*rn=nn;
222		ret=NULL;
223		lh->num_insert++;
224		lh->num_items++;
225		}
226	else /* replace same key */
227		{
228		ret= (*rn)->data;
229		(*rn)->data=data;
230		lh->num_replace++;
231		}
232	return(ret);
233	}
234
235void *lh_delete(LHASH *lh, void *data)
236	{
237	unsigned long hash;
238	LHASH_NODE *nn,**rn;
239	void *ret;
240
241	lh->error=0;
242	rn=getrn(lh,data,&hash);
243
244	if (*rn == NULL)
245		{
246		lh->num_no_delete++;
247		return(NULL);
248		}
249	else
250		{
251		nn= *rn;
252		*rn=nn->next;
253		ret=nn->data;
254		Free(nn);
255		lh->num_delete++;
256		}
257
258	lh->num_items--;
259	if ((lh->num_nodes > MIN_NODES) &&
260		(lh->down_load >= (lh->num_items*LH_LOAD_MULT/lh->num_nodes)))
261		contract(lh);
262
263	return(ret);
264	}
265
266void *lh_retrieve(LHASH *lh, void *data)
267	{
268	unsigned long hash;
269	LHASH_NODE **rn;
270	void *ret;
271
272	lh->error=0;
273	rn=getrn(lh,data,&hash);
274
275	if (*rn == NULL)
276		{
277		lh->num_retrieve_miss++;
278		return(NULL);
279		}
280	else
281		{
282		ret= (*rn)->data;
283		lh->num_retrieve++;
284		}
285	return(ret);
286	}
287
288void lh_doall(LHASH *lh, void (*func)())
289	{
290	lh_doall_arg(lh,func,NULL);
291	}
292
293void lh_doall_arg(LHASH *lh, void (*func)(), void *arg)
294	{
295	int i;
296	LHASH_NODE *a,*n;
297
298	/* reverse the order so we search from 'top to bottom'
299	 * We were having memory leaks otherwise */
300	for (i=lh->num_nodes-1; i>=0; i--)
301		{
302		a=lh->b[i];
303		while (a != NULL)
304			{
305			/* 28/05/91 - eay - n added so items can be deleted
306			 * via lh_doall */
307			n=a->next;
308			func(a->data,arg);
309			a=n;
310			}
311		}
312	}
313
314static void expand(LHASH *lh)
315	{
316	LHASH_NODE **n,**n1,**n2,*np;
317	unsigned int p,i,j;
318	unsigned long hash,nni;
319
320	lh->num_nodes++;
321	lh->num_expands++;
322	p=(int)lh->p++;
323	n1= &(lh->b[p]);
324	n2= &(lh->b[p+(int)lh->pmax]);
325	*n2=NULL;        /* 27/07/92 - eay - undefined pointer bug */
326	nni=lh->num_alloc_nodes;
327
328	for (np= *n1; np != NULL; )
329		{
330#ifndef NO_HASH_COMP
331		hash=np->hash;
332#else
333		hash=(*(lh->hash))(np->data);
334		lh->num_hash_calls++;
335#endif
336		if ((hash%nni) != p)
337			{ /* move it */
338			*n1= (*n1)->next;
339			np->next= *n2;
340			*n2=np;
341			}
342		else
343			n1= &((*n1)->next);
344		np= *n1;
345		}
346
347	if ((lh->p) >= lh->pmax)
348		{
349		j=(int)lh->num_alloc_nodes*2;
350		n=(LHASH_NODE **)Realloc(lh->b,
351			(unsigned int)sizeof(LHASH_NODE *)*j);
352		if (n == NULL)
353			{
354/*			fputs("realloc error in lhash",stderr); */
355			lh->error++;
356			lh->p=0;
357			return;
358			}
359		/* else */
360		for (i=(int)lh->num_alloc_nodes; i<j; i++)/* 26/02/92 eay */
361			n[i]=NULL;			  /* 02/03/92 eay */
362		lh->pmax=lh->num_alloc_nodes;
363		lh->num_alloc_nodes=j;
364		lh->num_expand_reallocs++;
365		lh->p=0;
366		lh->b=n;
367		}
368	}
369
370static void contract(LHASH *lh)
371	{
372	LHASH_NODE **n,*n1,*np;
373
374	np=lh->b[lh->p+lh->pmax-1];
375	lh->b[lh->p+lh->pmax-1]=NULL; /* 24/07-92 - eay - weird but :-( */
376	if (lh->p == 0)
377		{
378		n=(LHASH_NODE **)Realloc(lh->b,
379			(unsigned int)(sizeof(LHASH_NODE *)*lh->pmax));
380		if (n == NULL)
381			{
382/*			fputs("realloc error in lhash",stderr); */
383			lh->error++;
384			return;
385			}
386		lh->num_contract_reallocs++;
387		lh->num_alloc_nodes/=2;
388		lh->pmax/=2;
389		lh->p=lh->pmax-1;
390		lh->b=n;
391		}
392	else
393		lh->p--;
394
395	lh->num_nodes--;
396	lh->num_contracts++;
397
398	n1=lh->b[(int)lh->p];
399	if (n1 == NULL)
400		lh->b[(int)lh->p]=np;
401	else
402		{
403		while (n1->next != NULL)
404			n1=n1->next;
405		n1->next=np;
406		}
407	}
408
409static LHASH_NODE **getrn(LHASH *lh, void *data, unsigned long *rhash)
410	{
411	LHASH_NODE **ret,*n1;
412	unsigned long hash,nn;
413	int (*cf)();
414
415	hash=(*(lh->hash))(data);
416	lh->num_hash_calls++;
417	*rhash=hash;
418
419	nn=hash%lh->pmax;
420	if (nn < lh->p)
421		nn=hash%lh->num_alloc_nodes;
422
423	cf=lh->comp;
424	ret= &(lh->b[(int)nn]);
425	for (n1= *ret; n1 != NULL; n1=n1->next)
426		{
427#ifndef NO_HASH_COMP
428		lh->num_hash_comps++;
429		if (n1->hash != hash)
430			{
431			ret= &(n1->next);
432			continue;
433			}
434#endif
435		lh->num_comp_calls++;
436		if ((*cf)(n1->data,data) == 0)
437			break;
438		ret= &(n1->next);
439		}
440	return(ret);
441	}
442
443/* The following hash seems to work very well on normal text strings
444 * no collisions on /usr/dict/words and it distributes on %2^n quite
445 * well, not as good as MD5, but still good.
446 */
447unsigned long lh_strhash(const char *c)
448	{
449	unsigned long ret=0;
450	long n;
451	unsigned long v;
452	int r;
453
454	if ((c == NULL) || (*c == '\0'))
455		return(ret);
456/*
457	unsigned char b[16];
458	MD5(c,strlen(c),b);
459	return(b[0]|(b[1]<<8)|(b[2]<<16)|(b[3]<<24));
460*/
461
462	n=0x100;
463	while (*c)
464		{
465		v=n|(*c);
466		n+=0x100;
467		r= (int)((v>>2)^v)&0x0f;
468		ret=(ret<<r)|(ret>>(32-r));
469		ret&=0xFFFFFFFFL;
470		ret^=v*v;
471		c++;
472		}
473	return((ret>>16)^ret);
474	}
475
476unsigned long lh_num_items(LHASH *lh)
477	{
478	return lh ? lh->num_items : 0;
479	}
480