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_zalloc(sizeof(OPENSSL_STACK));
117 OPENSSL_STACK *OPENSSL_sk_new(OPENSSL_sk_compfunc c)
119 OPENSSL_STACK *ret = OPENSSL_sk_new_null();
127 * Calculate the array growth based on the target size.
129 * The growth fraction is a rational number and is defined by a numerator
130 * and a denominator. According to Andrew Koenig in his paper "Why Are
131 * Vectors Efficient?" from JOOP 11(5) 1998, this factor should be less
132 * than the golden ratio (1.618...).
134 * We use 3/2 = 1.5 for simplicity of calculation and overflow checking.
135 * Another option 8/5 = 1.6 allows for slightly faster growth, although safe
136 * computation is more difficult.
138 * The limit to avoid overflow is spot on. The modulo three correction term
139 * ensures that the limit is the largest number than can be expanded by the
140 * growth factor without exceeding the hard limit.
142 * Do not call it with |current| lower than 2, or it will infinitely loop.
144 static ossl_inline int compute_growth(int target, int current)
146 const int limit = (max_nodes / 3) * 2 + (max_nodes % 3 ? 1 : 0);
148 while (current < target) {
149 /* Check to see if we're at the hard limit */
150 if (current >= max_nodes)
153 /* Expand the size by a factor of 3/2 if it is within range */
154 current = current < limit ? current + current / 2 : max_nodes;
159 /* internal STACK storage allocation */
160 static int sk_reserve(OPENSSL_STACK *st, int n, int exact)
162 const void **tmpdata;
165 /* Check to see the reservation isn't exceeding the hard limit */
166 if (n > max_nodes - st->num)
169 /* Figure out the new size */
170 num_alloc = st->num + n;
171 if (num_alloc < min_nodes)
172 num_alloc = min_nodes;
174 /* If |st->data| allocation was postponed */
175 if (st->data == NULL) {
177 * At this point, |st->num_alloc| and |st->num| are 0;
178 * so |num_alloc| value is |n| or |min_nodes| if greater than |n|.
180 st->data = OPENSSL_zalloc(sizeof(void *) * num_alloc);
181 if (st->data == NULL)
183 st->num_alloc = num_alloc;
188 if (num_alloc <= st->num_alloc)
190 num_alloc = compute_growth(num_alloc, st->num_alloc);
193 } else if (num_alloc == st->num_alloc) {
197 tmpdata = OPENSSL_realloc((void *)st->data, sizeof(void *) * num_alloc);
202 st->num_alloc = num_alloc;
206 int OPENSSL_sk_reserve(OPENSSL_STACK *st, int n)
213 return sk_reserve(st, n, 1);
216 int OPENSSL_sk_insert(OPENSSL_STACK *st, const void *data, int loc)
218 if (st == NULL || st->num == max_nodes)
221 if (!sk_reserve(st, 1, 0))
224 if ((loc >= st->num) || (loc < 0)) {
225 st->data[st->num] = data;
227 memmove(&st->data[loc + 1], &st->data[loc],
228 sizeof(st->data[0]) * (st->num - loc));
229 st->data[loc] = data;
236 static ossl_inline void *internal_delete(OPENSSL_STACK *st, int loc)
238 const void *ret = st->data[loc];
240 if (loc != st->num - 1)
241 memmove(&st->data[loc], &st->data[loc + 1],
242 sizeof(st->data[0]) * (st->num - loc - 1));
248 void *OPENSSL_sk_delete_ptr(OPENSSL_STACK *st, const void *p)
252 for (i = 0; i < st->num; i++)
253 if (st->data[i] == p)
254 return internal_delete(st, i);
258 void *OPENSSL_sk_delete(OPENSSL_STACK *st, int loc)
260 if (st == NULL || loc < 0 || loc >= st->num)
263 return internal_delete(st, loc);
266 static int internal_find(OPENSSL_STACK *st, const void *data,
272 if (st == NULL || st->num == 0)
275 if (st->comp == NULL) {
276 for (i = 0; i < st->num; i++)
277 if (st->data[i] == data)
284 qsort(st->data, st->num, sizeof(void *), st->comp);
285 st->sorted = 1; /* empty or single-element stack is considered sorted */
289 r = OBJ_bsearch_ex_(&data, st->data, st->num, sizeof(void *), st->comp,
292 return r == NULL ? -1 : (int)((const void **)r - st->data);
295 int OPENSSL_sk_find(OPENSSL_STACK *st, const void *data)
297 return internal_find(st, data, OBJ_BSEARCH_FIRST_VALUE_ON_MATCH);
300 int OPENSSL_sk_find_ex(OPENSSL_STACK *st, const void *data)
302 return internal_find(st, data, OBJ_BSEARCH_VALUE_ON_NOMATCH);
305 int OPENSSL_sk_push(OPENSSL_STACK *st, const void *data)
309 return OPENSSL_sk_insert(st, data, st->num);
312 int OPENSSL_sk_unshift(OPENSSL_STACK *st, const void *data)
314 return OPENSSL_sk_insert(st, data, 0);
317 void *OPENSSL_sk_shift(OPENSSL_STACK *st)
319 if (st == NULL || st->num == 0)
321 return internal_delete(st, 0);
324 void *OPENSSL_sk_pop(OPENSSL_STACK *st)
326 if (st == NULL || st->num == 0)
328 return internal_delete(st, st->num - 1);
331 void OPENSSL_sk_zero(OPENSSL_STACK *st)
333 if (st == NULL || st->num == 0)
335 memset(st->data, 0, sizeof(*st->data) * st->num);
339 void OPENSSL_sk_pop_free(OPENSSL_STACK *st, OPENSSL_sk_freefunc func)
345 for (i = 0; i < st->num; i++)
346 if (st->data[i] != NULL)
347 func((char *)st->data[i]);
351 void OPENSSL_sk_free(OPENSSL_STACK *st)
355 OPENSSL_free(st->data);
359 int OPENSSL_sk_num(const OPENSSL_STACK *st)
361 return st == NULL ? -1 : st->num;
364 void *OPENSSL_sk_value(const OPENSSL_STACK *st, int i)
366 if (st == NULL || i < 0 || i >= st->num)
368 return (void *)st->data[i];
371 void *OPENSSL_sk_set(OPENSSL_STACK *st, int i, const void *data)
373 if (st == NULL || i < 0 || i >= st->num)
377 return (void *)st->data[i];
380 void OPENSSL_sk_sort(OPENSSL_STACK *st)
382 if (st != NULL && !st->sorted && st->comp != NULL) {
384 qsort(st->data, st->num, sizeof(void *), st->comp);
385 st->sorted = 1; /* empty or single-element stack is considered sorted */
389 int OPENSSL_sk_is_sorted(const OPENSSL_STACK *st)
391 return st == NULL ? 1 : st->sorted;