ref: bfe9da47cfa2f51ebef78c59332b5ba2deba306d
dir: /third_party/boringssl/src/crypto/stack/stack.c/
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.] */
#include <openssl/stack.h>
#include <assert.h>
#include <openssl/mem.h>
#include "../internal.h"
// kMinSize is the number of pointers that will be initially allocated in a new
// stack.
static const size_t kMinSize = 4;
_STACK *sk_new(stack_cmp_func comp) {
_STACK *ret = OPENSSL_malloc(sizeof(_STACK));
if (ret == NULL) {
return NULL;
}
OPENSSL_memset(ret, 0, sizeof(_STACK));
ret->data = OPENSSL_malloc(sizeof(void *) * kMinSize);
if (ret->data == NULL) {
goto err;
}
OPENSSL_memset(ret->data, 0, sizeof(void *) * kMinSize);
ret->comp = comp;
ret->num_alloc = kMinSize;
return ret;
err:
OPENSSL_free(ret);
return NULL;
}
_STACK *sk_new_null(void) { return sk_new(NULL); }
size_t sk_num(const _STACK *sk) {
if (sk == NULL) {
return 0;
}
return sk->num;
}
void sk_zero(_STACK *sk) {
if (sk == NULL || sk->num == 0) {
return;
}
OPENSSL_memset(sk->data, 0, sizeof(void*) * sk->num);
sk->num = 0;
sk->sorted = 0;
}
void *sk_value(const _STACK *sk, size_t i) {
if (!sk || i >= sk->num) {
return NULL;
}
return sk->data[i];
}
void *sk_set(_STACK *sk, size_t i, void *value) {
if (!sk || i >= sk->num) {
return NULL;
}
return sk->data[i] = value;
}
void sk_free(_STACK *sk) {
if (sk == NULL) {
return;
}
OPENSSL_free(sk->data);
OPENSSL_free(sk);
}
void sk_pop_free_ex(_STACK *sk, void (*call_free_func)(stack_free_func, void *),
stack_free_func free_func) {
if (sk == NULL) {
return;
}
for (size_t i = 0; i < sk->num; i++) {
if (sk->data[i] != NULL) {
call_free_func(free_func, sk->data[i]);
}
}
sk_free(sk);
}
// Historically, |sk_pop_free| called the function as |stack_free_func|
// directly. This is undefined in C. Some callers called |sk_pop_free| directly,
// so we must maintain a compatibility version for now.
static void call_free_func_legacy(stack_free_func func, void *ptr) {
func(ptr);
}
void sk_pop_free(_STACK *sk, stack_free_func free_func) {
sk_pop_free_ex(sk, call_free_func_legacy, free_func);
}
size_t sk_insert(_STACK *sk, void *p, size_t where) {
if (sk == NULL) {
return 0;
}
if (sk->num_alloc <= sk->num + 1) {
// Attempt to double the size of the array.
size_t new_alloc = sk->num_alloc << 1;
size_t alloc_size = new_alloc * sizeof(void *);
void **data;
// If the doubling overflowed, try to increment.
if (new_alloc < sk->num_alloc || alloc_size / sizeof(void *) != new_alloc) {
new_alloc = sk->num_alloc + 1;
alloc_size = new_alloc * sizeof(void *);
}
// If the increment also overflowed, fail.
if (new_alloc < sk->num_alloc || alloc_size / sizeof(void *) != new_alloc) {
return 0;
}
data = OPENSSL_realloc(sk->data, alloc_size);
if (data == NULL) {
return 0;
}
sk->data = data;
sk->num_alloc = new_alloc;
}
if (where >= sk->num) {
sk->data[sk->num] = p;
} else {
OPENSSL_memmove(&sk->data[where + 1], &sk->data[where],
sizeof(void *) * (sk->num - where));
sk->data[where] = p;
}
sk->num++;
sk->sorted = 0;
return sk->num;
}
void *sk_delete(_STACK *sk, size_t where) {
void *ret;
if (!sk || where >= sk->num) {
return NULL;
}
ret = sk->data[where];
if (where != sk->num - 1) {
OPENSSL_memmove(&sk->data[where], &sk->data[where + 1],
sizeof(void *) * (sk->num - where - 1));
}
sk->num--;
return ret;
}
void *sk_delete_ptr(_STACK *sk, const void *p) {
if (sk == NULL) {
return NULL;
}
for (size_t i = 0; i < sk->num; i++) {
if (sk->data[i] == p) {
return sk_delete(sk, i);
}
}
return NULL;
}
int sk_find(const _STACK *sk, size_t *out_index, const void *p,
int (*call_cmp_func)(stack_cmp_func, const void **,
const void **)) {
if (sk == NULL) {
return 0;
}
if (sk->comp == NULL) {
// Use pointer equality when no comparison function has been set.
for (size_t i = 0; i < sk->num; i++) {
if (sk->data[i] == p) {
if (out_index) {
*out_index = i;
}
return 1;
}
}
return 0;
}
if (p == NULL) {
return 0;
}
if (!sk_is_sorted(sk)) {
for (size_t i = 0; i < sk->num; i++) {
const void *elem = sk->data[i];
if (call_cmp_func(sk->comp, &p, &elem) == 0) {
if (out_index) {
*out_index = i;
}
return 1;
}
}
return 0;
}
// The stack is sorted, so binary search to find the element.
//
// |lo| and |hi| maintain a half-open interval of where the answer may be. All
// indices such that |lo <= idx < hi| are candidates.
size_t lo = 0, hi = sk->num;
while (lo < hi) {
// Bias |mid| towards |lo|. See the |r == 0| case below.
size_t mid = lo + (hi - lo - 1) / 2;
assert(lo <= mid && mid < hi);
const void *elem = sk->data[mid];
int r = call_cmp_func(sk->comp, &p, &elem);
if (r > 0) {
lo = mid + 1; // |mid| is too low.
} else if (r < 0) {
hi = mid; // |mid| is too high.
} else {
// |mid| matches. However, this function returns the earliest match, so we
// can only return if the range has size one.
if (hi - lo == 1) {
if (out_index != NULL) {
*out_index = mid;
}
return 1;
}
// The sample is biased towards |lo|. |mid| can only be |hi - 1| if
// |hi - lo| was one, so this makes forward progress.
assert(mid + 1 < hi);
hi = mid + 1;
}
}
assert(lo == hi);
return 0; // Not found.
}
void *sk_shift(_STACK *sk) {
if (sk == NULL) {
return NULL;
}
if (sk->num == 0) {
return NULL;
}
return sk_delete(sk, 0);
}
size_t sk_push(_STACK *sk, void *p) { return (sk_insert(sk, p, sk->num)); }
void *sk_pop(_STACK *sk) {
if (sk == NULL) {
return NULL;
}
if (sk->num == 0) {
return NULL;
}
return sk_delete(sk, sk->num - 1);
}
_STACK *sk_dup(const _STACK *sk) {
if (sk == NULL) {
return NULL;
}
_STACK *ret = OPENSSL_malloc(sizeof(_STACK));
if (ret == NULL) {
return NULL;
}
OPENSSL_memset(ret, 0, sizeof(_STACK));
ret->data = OPENSSL_malloc(sizeof(void *) * sk->num_alloc);
if (ret->data == NULL) {
goto err;
}
ret->num = sk->num;
OPENSSL_memcpy(ret->data, sk->data, sizeof(void *) * sk->num);
ret->sorted = sk->sorted;
ret->num_alloc = sk->num_alloc;
ret->comp = sk->comp;
return ret;
err:
sk_free(ret);
return NULL;
}
void sk_sort(_STACK *sk) {
if (sk == NULL || sk->comp == NULL || sk->sorted) {
return;
}
// sk->comp is a function that takes pointers to pointers to elements, but
// qsort take a comparison function that just takes pointers to elements.
// However, since we're passing an array of pointers to qsort, we can just
// cast the comparison function and everything works.
//
// TODO(davidben): This is undefined behavior, but the call is in libc so,
// e.g., CFI does not notice. Unfortunately, |qsort| is missing a void*
// parameter in its callback and |qsort_s| / |qsort_r| are a mess of
// incompatibility.
if (sk->num >= 2) {
int (*comp_func)(const void *, const void *) =
(int (*)(const void *, const void *))(sk->comp);
qsort(sk->data, sk->num, sizeof(void *), comp_func);
}
sk->sorted = 1;
}
int sk_is_sorted(const _STACK *sk) {
if (!sk) {
return 1;
}
return sk->sorted;
}
stack_cmp_func sk_set_cmp_func(_STACK *sk, stack_cmp_func comp) {
stack_cmp_func old = sk->comp;
if (sk->comp != comp) {
sk->sorted = 0;
}
sk->comp = comp;
return old;
}
_STACK *sk_deep_copy(const _STACK *sk,
void *(*call_copy_func)(stack_copy_func, void *),
stack_copy_func copy_func,
void (*call_free_func)(stack_free_func, void *),
stack_free_func free_func) {
_STACK *ret = sk_dup(sk);
if (ret == NULL) {
return NULL;
}
for (size_t i = 0; i < ret->num; i++) {
if (ret->data[i] == NULL) {
continue;
}
ret->data[i] = call_copy_func(copy_func, ret->data[i]);
if (ret->data[i] == NULL) {
for (size_t j = 0; j < i; j++) {
if (ret->data[j] != NULL) {
call_free_func(free_func, ret->data[j]);
}
}
sk_free(ret);
return NULL;
}
}
return ret;
}