1 /* $OpenBSD: lhash.c,v 1.19 2019/05/12 00:09:59 beck Exp $ */
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
101 #include <openssl/opensslconf.h>
102
103 #include <openssl/crypto.h>
104 #include <openssl/lhash.h>
105
106 #undef MIN_NODES
107 #define MIN_NODES 16
108 #define UP_LOAD (2*LH_LOAD_MULT) /* load times 256 (default 2) */
109 #define DOWN_LOAD (LH_LOAD_MULT) /* load times 256 (default 1) */
110
111 static void expand(_LHASH *lh);
112 static void contract(_LHASH *lh);
113 static LHASH_NODE **getrn(_LHASH *lh, const void *data, unsigned long *rhash);
114
115 _LHASH *
lh_new(LHASH_HASH_FN_TYPE h,LHASH_COMP_FN_TYPE c)116 lh_new(LHASH_HASH_FN_TYPE h, LHASH_COMP_FN_TYPE c)
117 {
118 _LHASH *ret;
119
120 if ((ret = calloc(1, sizeof(_LHASH))) == NULL)
121 return NULL;
122 if ((ret->b = calloc(MIN_NODES, sizeof(LHASH_NODE *))) == NULL) {
123 free(ret);
124 return NULL;
125 }
126 ret->comp = ((c == NULL) ? (LHASH_COMP_FN_TYPE)strcmp : c);
127 ret->hash = ((h == NULL) ? (LHASH_HASH_FN_TYPE)lh_strhash : h);
128 ret->num_nodes = MIN_NODES / 2;
129 ret->num_alloc_nodes = MIN_NODES;
130 ret->pmax = MIN_NODES / 2;
131 ret->up_load = UP_LOAD;
132 ret->down_load = DOWN_LOAD;
133
134 return (ret);
135 }
136
137 void
lh_free(_LHASH * lh)138 lh_free(_LHASH *lh)
139 {
140 unsigned int i;
141 LHASH_NODE *n, *nn;
142
143 if (lh == NULL)
144 return;
145
146 for (i = 0; i < lh->num_nodes; i++) {
147 n = lh->b[i];
148 while (n != NULL) {
149 nn = n->next;
150 free(n);
151 n = nn;
152 }
153 }
154 free(lh->b);
155 free(lh);
156 }
157
158 void *
lh_insert(_LHASH * lh,void * data)159 lh_insert(_LHASH *lh, void *data)
160 {
161 unsigned long hash;
162 LHASH_NODE *nn, **rn;
163 void *ret;
164
165 lh->error = 0;
166 if (lh->up_load <= (lh->num_items * LH_LOAD_MULT / lh->num_nodes))
167 expand(lh);
168
169 rn = getrn(lh, data, &hash);
170
171 if (*rn == NULL) {
172 if ((nn = malloc(sizeof(LHASH_NODE))) == NULL) {
173 lh->error++;
174 return (NULL);
175 }
176 nn->data = data;
177 nn->next = NULL;
178 #ifndef OPENSSL_NO_HASH_COMP
179 nn->hash = hash;
180 #endif
181 *rn = nn;
182 ret = NULL;
183 lh->num_insert++;
184 lh->num_items++;
185 }
186 else /* replace same key */
187 {
188 ret = (*rn)->data;
189 (*rn)->data = data;
190 lh->num_replace++;
191 }
192 return (ret);
193 }
194
195 void *
lh_delete(_LHASH * lh,const void * data)196 lh_delete(_LHASH *lh, const void *data)
197 {
198 unsigned long hash;
199 LHASH_NODE *nn, **rn;
200 void *ret;
201
202 lh->error = 0;
203 rn = getrn(lh, data, &hash);
204
205 if (*rn == NULL) {
206 lh->num_no_delete++;
207 return (NULL);
208 } else {
209 nn= *rn;
210 *rn = nn->next;
211 ret = nn->data;
212 free(nn);
213 lh->num_delete++;
214 }
215
216 lh->num_items--;
217 if ((lh->num_nodes > MIN_NODES) &&
218 (lh->down_load >= (lh->num_items * LH_LOAD_MULT / lh->num_nodes)))
219 contract(lh);
220
221 return (ret);
222 }
223
224 void *
lh_retrieve(_LHASH * lh,const void * data)225 lh_retrieve(_LHASH *lh, const void *data)
226 {
227 unsigned long hash;
228 LHASH_NODE **rn;
229 void *ret;
230
231 lh->error = 0;
232 rn = getrn(lh, data, &hash);
233
234 if (*rn == NULL) {
235 lh->num_retrieve_miss++;
236 return (NULL);
237 } else {
238 ret = (*rn)->data;
239 lh->num_retrieve++;
240 }
241 return (ret);
242 }
243
244 static void
doall_util_fn(_LHASH * lh,int use_arg,LHASH_DOALL_FN_TYPE func,LHASH_DOALL_ARG_FN_TYPE func_arg,void * arg)245 doall_util_fn(_LHASH *lh, int use_arg, LHASH_DOALL_FN_TYPE func,
246 LHASH_DOALL_ARG_FN_TYPE func_arg, void *arg)
247 {
248 int i;
249 LHASH_NODE *a, *n;
250
251 if (lh == NULL)
252 return;
253
254 /* reverse the order so we search from 'top to bottom'
255 * We were having memory leaks otherwise */
256 for (i = lh->num_nodes - 1; i >= 0; i--) {
257 a = lh->b[i];
258 while (a != NULL) {
259 /* 28/05/91 - eay - n added so items can be deleted
260 * via lh_doall */
261 /* 22/05/08 - ben - eh? since a is not passed,
262 * this should not be needed */
263 n = a->next;
264 if (use_arg)
265 func_arg(a->data, arg);
266 else
267 func(a->data);
268 a = n;
269 }
270 }
271 }
272
273 void
lh_doall(_LHASH * lh,LHASH_DOALL_FN_TYPE func)274 lh_doall(_LHASH *lh, LHASH_DOALL_FN_TYPE func)
275 {
276 doall_util_fn(lh, 0, func, (LHASH_DOALL_ARG_FN_TYPE)0, NULL);
277 }
278
279 void
lh_doall_arg(_LHASH * lh,LHASH_DOALL_ARG_FN_TYPE func,void * arg)280 lh_doall_arg(_LHASH *lh, LHASH_DOALL_ARG_FN_TYPE func, void *arg)
281 {
282 doall_util_fn(lh, 1, (LHASH_DOALL_FN_TYPE)0, func, arg);
283 }
284
285 static void
expand(_LHASH * lh)286 expand(_LHASH *lh)
287 {
288 LHASH_NODE **n, **n1, **n2, *np;
289 unsigned int p, i, j;
290 unsigned long hash, nni;
291
292 lh->num_nodes++;
293 lh->num_expands++;
294 p = (int)lh->p++;
295 n1 = &(lh->b[p]);
296 n2 = &(lh->b[p + (int)lh->pmax]);
297 *n2 = NULL; /* 27/07/92 - eay - undefined pointer bug */
298 nni = lh->num_alloc_nodes;
299
300 for (np = *n1; np != NULL; ) {
301 #ifndef OPENSSL_NO_HASH_COMP
302 hash = np->hash;
303 #else
304 hash = lh->hash(np->data);
305 lh->num_hash_calls++;
306 #endif
307 if ((hash % nni) != p) { /* move it */
308 *n1 = (*n1)->next;
309 np->next= *n2;
310 *n2 = np;
311 } else
312 n1 = &((*n1)->next);
313 np= *n1;
314 }
315
316 if ((lh->p) >= lh->pmax) {
317 j = (int)lh->num_alloc_nodes * 2;
318 n = reallocarray(lh->b, j, sizeof(LHASH_NODE *));
319 if (n == NULL) {
320 /* fputs("realloc error in lhash", stderr); */
321 lh->error++;
322 lh->p = 0;
323 return;
324 }
325 /* else */
326 for (i = (int)lh->num_alloc_nodes; i < j; i++)/* 26/02/92 eay */
327 n[i] = NULL; /* 02/03/92 eay */
328 lh->pmax = lh->num_alloc_nodes;
329 lh->num_alloc_nodes = j;
330 lh->num_expand_reallocs++;
331 lh->p = 0;
332 lh->b = n;
333 }
334 }
335
336 static void
contract(_LHASH * lh)337 contract(_LHASH *lh)
338 {
339 LHASH_NODE **n, *n1, *np;
340
341 np = lh->b[lh->p + lh->pmax - 1];
342 lh->b[lh->p+lh->pmax - 1] = NULL; /* 24/07-92 - eay - weird but :-( */
343 if (lh->p == 0) {
344 n = reallocarray(lh->b, lh->pmax, sizeof(LHASH_NODE *));
345 if (n == NULL) {
346 /* fputs("realloc error in lhash", stderr); */
347 lh->error++;
348 return;
349 }
350 lh->num_contract_reallocs++;
351 lh->num_alloc_nodes /= 2;
352 lh->pmax /= 2;
353 lh->p = lh->pmax - 1;
354 lh->b = n;
355 } else
356 lh->p--;
357
358 lh->num_nodes--;
359 lh->num_contracts++;
360
361 n1 = lh->b[(int)lh->p];
362 if (n1 == NULL)
363 lh->b[(int)lh->p] = np;
364 else {
365 while (n1->next != NULL)
366 n1 = n1->next;
367 n1->next = np;
368 }
369 }
370
getrn(_LHASH * lh,const void * data,unsigned long * rhash)371 static LHASH_NODE **getrn(_LHASH *lh, const void *data, unsigned long *rhash)
372 {
373 LHASH_NODE **ret, *n1;
374 unsigned long hash, nn;
375 LHASH_COMP_FN_TYPE cf;
376
377 hash = (*(lh->hash))(data);
378 lh->num_hash_calls++;
379 *rhash = hash;
380
381 nn = hash % lh->pmax;
382 if (nn < lh->p)
383 nn = hash % lh->num_alloc_nodes;
384
385 cf = lh->comp;
386 ret = &(lh->b[(int)nn]);
387 for (n1 = *ret; n1 != NULL; n1 = n1->next) {
388 #ifndef OPENSSL_NO_HASH_COMP
389 lh->num_hash_comps++;
390 if (n1->hash != hash) {
391 ret = &(n1->next);
392 continue;
393 }
394 #endif
395 lh->num_comp_calls++;
396 if (cf(n1->data, data) == 0)
397 break;
398 ret = &(n1->next);
399 }
400 return (ret);
401 }
402
403 /* The following hash seems to work very well on normal text strings
404 * no collisions on /usr/dict/words and it distributes on %2^n quite
405 * well, not as good as MD5, but still good.
406 */
407 unsigned long
lh_strhash(const char * c)408 lh_strhash(const char *c)
409 {
410 unsigned long ret = 0;
411 unsigned long n, v;
412 unsigned int r;
413
414 if (c == NULL || *c == '\0')
415 return ret;
416
417 n = 0x100;
418 while (*c) {
419 v = n | *c;
420 n += 0x100;
421 if ((r = ((v >> 2) ^ v) & 0x0f) != 0)
422 ret = (ret << r) | (ret >> (32 - r));
423 ret &= 0xFFFFFFFFUL;
424 ret ^= v * v;
425 c++;
426 }
427 return (ret >> 16) ^ ret;
428 }
429
430 unsigned long
lh_num_items(const _LHASH * lh)431 lh_num_items(const _LHASH *lh)
432 {
433 return lh ? lh->num_items : 0;
434 }
435