2 * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 #include "internal/cryptlib.h"
12 #include "internal/numbers.h"
13 #include <openssl/stack.h>
14 #include <openssl/objects.h>
16 #include <openssl/e_os2.h> /* For ossl_inline */
19 * The initial number of nodes in the array.
21 static const int min_nodes = 4;
22 static const int max_nodes = SIZE_MAX / sizeof(void *) < INT_MAX
23 ? (int)(SIZE_MAX / sizeof(void *))
31 OPENSSL_sk_compfunc comp;
34 OPENSSL_sk_compfunc OPENSSL_sk_set_cmp_func(OPENSSL_STACK *sk, OPENSSL_sk_compfunc c)
36 OPENSSL_sk_compfunc old = sk->comp;
45 OPENSSL_STACK *OPENSSL_sk_dup(const OPENSSL_STACK *sk)
49 if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL)
52 /* direct structure assignment */
56 /* postpone |ret->data| allocation */
61 /* duplicate |sk->data| content */
62 if ((ret->data = OPENSSL_malloc(sizeof(*ret->data) * sk->num_alloc)) == NULL)
64 memcpy(ret->data, sk->data, sizeof(void *) * sk->num);
71 OPENSSL_STACK *OPENSSL_sk_deep_copy(const OPENSSL_STACK *sk,
72 OPENSSL_sk_copyfunc copy_func,
73 OPENSSL_sk_freefunc free_func)
78 if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL)
81 /* direct structure assignment */
85 /* postpone |ret| data allocation */
91 ret->num_alloc = sk->num > min_nodes ? sk->num : min_nodes;
92 ret->data = OPENSSL_zalloc(sizeof(*ret->data) * ret->num_alloc);
93 if (ret->data == NULL) {
98 for (i = 0; i < ret->num; ++i) {
99 if (sk->data[i] == NULL)
101 if ((ret->data[i] = copy_func(sk->data[i])) == NULL) {
103 if (ret->data[i] != NULL)
104 free_func((void *)ret->data[i]);
105 OPENSSL_sk_free(ret);
112 OPENSSL_STACK *OPENSSL_sk_new_null(void)
114 return OPENSSL_sk_new_reserve(NULL, 0);
117 OPENSSL_STACK *OPENSSL_sk_new(OPENSSL_sk_compfunc c)
119 return OPENSSL_sk_new_reserve(c, 0);
123 * Calculate the array growth based on the target size.
125 * The growth fraction is a rational number and is defined by a numerator
126 * and a denominator. According to Andrew Koenig in his paper "Why Are
127 * Vectors Efficient?" from JOOP 11(5) 1998, this factor should be less
128 * than the golden ratio (1.618...).
130 * We use 3/2 = 1.5 for simplicity of calculation and overflow checking.
131 * Another option 8/5 = 1.6 allows for slightly faster growth, although safe
132 * computation is more difficult.
134 * The limit to avoid overflow is spot on. The modulo three correction term
135 * ensures that the limit is the largest number than can be expanded by the
136 * growth factor without exceeding the hard limit.
138 * Do not call it with |current| lower than 2, or it will infinitely loop.
140 static ossl_inline int compute_growth(int target, int current)
142 const int limit = (max_nodes / 3) * 2 + (max_nodes % 3 ? 1 : 0);
144 while (current < target) {
145 /* Check to see if we're at the hard limit */
146 if (current >= max_nodes)
149 /* Expand the size by a factor of 3/2 if it is within range */
150 current = current < limit ? current + current / 2 : max_nodes;
155 /* internal STACK storage allocation */
156 static int sk_reserve(OPENSSL_STACK *st, int n, int exact)
158 const void **tmpdata;
161 /* Check to see the reservation isn't exceeding the hard limit */
162 if (n > max_nodes - st->num)
165 /* Figure out the new size */
166 num_alloc = st->num + n;
167 if (num_alloc < min_nodes)
168 num_alloc = min_nodes;
170 /* If |st->data| allocation was postponed */
171 if (st->data == NULL) {
173 * At this point, |st->num_alloc| and |st->num| are 0;
174 * so |num_alloc| value is |n| or |min_nodes| if greater than |n|.
176 st->data = OPENSSL_zalloc(sizeof(void *) * num_alloc);
177 if (st->data == NULL)
179 st->num_alloc = num_alloc;
184 if (num_alloc <= st->num_alloc)
186 num_alloc = compute_growth(num_alloc, st->num_alloc);
189 } else if (num_alloc == st->num_alloc) {
193 tmpdata = OPENSSL_realloc((void *)st->data, sizeof(void *) * num_alloc);
198 st->num_alloc = num_alloc;
202 OPENSSL_STACK *OPENSSL_sk_new_reserve(OPENSSL_sk_compfunc c, int n)
204 OPENSSL_STACK *st = OPENSSL_zalloc(sizeof(OPENSSL_STACK));
214 if (!sk_reserve(st, n, 1)) {
222 int OPENSSL_sk_reserve(OPENSSL_STACK *st, int n)
229 return sk_reserve(st, n, 1);
232 int OPENSSL_sk_insert(OPENSSL_STACK *st, const void *data, int loc)
234 if (st == NULL || st->num == max_nodes)
237 if (!sk_reserve(st, 1, 0))
240 if ((loc >= st->num) || (loc < 0)) {
241 st->data[st->num] = data;
243 memmove(&st->data[loc + 1], &st->data[loc],
244 sizeof(st->data[0]) * (st->num - loc));
245 st->data[loc] = data;
252 static ossl_inline void *internal_delete(OPENSSL_STACK *st, int loc)
254 const void *ret = st->data[loc];
256 if (loc != st->num - 1)
257 memmove(&st->data[loc], &st->data[loc + 1],
258 sizeof(st->data[0]) * (st->num - loc - 1));
264 void *OPENSSL_sk_delete_ptr(OPENSSL_STACK *st, const void *p)
268 for (i = 0; i < st->num; i++)
269 if (st->data[i] == p)
270 return internal_delete(st, i);
274 void *OPENSSL_sk_delete(OPENSSL_STACK *st, int loc)
276 if (st == NULL || loc < 0 || loc >= st->num)
279 return internal_delete(st, loc);
282 static int internal_find(OPENSSL_STACK *st, const void *data,
288 if (st == NULL || st->num == 0)
291 if (st->comp == NULL) {
292 for (i = 0; i < st->num; i++)
293 if (st->data[i] == data)
300 qsort(st->data, st->num, sizeof(void *), st->comp);
301 st->sorted = 1; /* empty or single-element stack is considered sorted */
305 r = OBJ_bsearch_ex_(&data, st->data, st->num, sizeof(void *), st->comp,
308 return r == NULL ? -1 : (int)((const void **)r - st->data);
311 int OPENSSL_sk_find(OPENSSL_STACK *st, const void *data)
313 return internal_find(st, data, OBJ_BSEARCH_FIRST_VALUE_ON_MATCH);
316 int OPENSSL_sk_find_ex(OPENSSL_STACK *st, const void *data)
318 return internal_find(st, data, OBJ_BSEARCH_VALUE_ON_NOMATCH);
321 int OPENSSL_sk_push(OPENSSL_STACK *st, const void *data)
325 return OPENSSL_sk_insert(st, data, st->num);
328 int OPENSSL_sk_unshift(OPENSSL_STACK *st, const void *data)
330 return OPENSSL_sk_insert(st, data, 0);
333 void *OPENSSL_sk_shift(OPENSSL_STACK *st)
335 if (st == NULL || st->num == 0)
337 return internal_delete(st, 0);
340 void *OPENSSL_sk_pop(OPENSSL_STACK *st)
342 if (st == NULL || st->num == 0)
344 return internal_delete(st, st->num - 1);
347 void OPENSSL_sk_zero(OPENSSL_STACK *st)
349 if (st == NULL || st->num == 0)
351 memset(st->data, 0, sizeof(*st->data) * st->num);
355 void OPENSSL_sk_pop_free(OPENSSL_STACK *st, OPENSSL_sk_freefunc func)
361 for (i = 0; i < st->num; i++)
362 if (st->data[i] != NULL)
363 func((char *)st->data[i]);
367 void OPENSSL_sk_free(OPENSSL_STACK *st)
371 OPENSSL_free(st->data);
375 int OPENSSL_sk_num(const OPENSSL_STACK *st)
377 return st == NULL ? -1 : st->num;
380 void *OPENSSL_sk_value(const OPENSSL_STACK *st, int i)
382 if (st == NULL || i < 0 || i >= st->num)
384 return (void *)st->data[i];
387 void *OPENSSL_sk_set(OPENSSL_STACK *st, int i, const void *data)
389 if (st == NULL || i < 0 || i >= st->num)
393 return (void *)st->data[i];
396 void OPENSSL_sk_sort(OPENSSL_STACK *st)
398 if (st != NULL && !st->sorted && st->comp != NULL) {
400 qsort(st->data, st->num, sizeof(void *), st->comp);
401 st->sorted = 1; /* empty or single-element stack is considered sorted */
405 int OPENSSL_sk_is_sorted(const OPENSSL_STACK *st)
407 return st == NULL ? 1 : st->sorted;