ref: 127dfcfefaec2397cb462ef797befd0b3611864e
dir: /third_party/boringssl/src/include/openssl/stack.h/
/* 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.] */
#ifndef OPENSSL_HEADER_STACK_H
#define OPENSSL_HEADER_STACK_H
#include <openssl/base.h>
#include <openssl/type_check.h>
#if defined(__cplusplus)
extern "C" {
#endif
// A stack, in OpenSSL, is an array of pointers. They are the most commonly
// used collection object.
//
// This file defines macros for type safe use of the stack functions. A stack
// of a specific type of object has type |STACK_OF(type)|. This can be defined
// (once) with |DEFINE_STACK_OF(type)| and declared where needed with
// |DECLARE_STACK_OF(type)|. For example:
//
// typedef struct foo_st {
// int bar;
// } FOO;
//
// DEFINE_STACK_OF(FOO)
//
// Although note that the stack will contain /pointers/ to |FOO|.
//
// A macro will be defined for each of the sk_* functions below. For
// STACK_OF(FOO), the macros would be sk_FOO_new, sk_FOO_pop etc.
// stack_free_func is a function that frees an element in a stack. Note its
// actual type is void (*)(T *) for some T. Low-level |sk_*| functions will be
// passed a type-specific wrapper to call it correctly.
typedef void (*stack_free_func)(void *ptr);
// stack_copy_func is a function that copies an element in a stack. Note its
// actual type is T *(*)(T *) for some T. Low-level |sk_*| functions will be
// passed a type-specific wrapper to call it correctly.
typedef void *(*stack_copy_func)(void *ptr);
// stack_cmp_func is a comparison function that returns a value < 0, 0 or > 0
// if |*a| is less than, equal to or greater than |*b|, respectively. Note the
// extra indirection - the function is given a pointer to a pointer to the
// element. This differs from the usual qsort/bsearch comparison function.
//
// Note its actual type is int (*)(const T **, const T **). Low-level |sk_*|
// functions will be passed a type-specific wrapper to call it correctly.
typedef int (*stack_cmp_func)(const void **a, const void **b);
// stack_st contains an array of pointers. It is not designed to be used
// directly, rather the wrapper macros should be used.
typedef struct stack_st {
// num contains the number of valid pointers in |data|.
size_t num;
void **data;
// sorted is non-zero if the values pointed to by |data| are in ascending
// order, based on |comp|.
int sorted;
// num_alloc contains the number of pointers allocated in the buffer pointed
// to by |data|, which may be larger than |num|.
size_t num_alloc;
// comp is an optional comparison function.
stack_cmp_func comp;
} _STACK;
#define STACK_OF(type) struct stack_st_##type
#define DECLARE_STACK_OF(type) STACK_OF(type);
// These are the raw stack functions, you shouldn't be using them. Rather you
// should be using the type stack macros implemented above.
// sk_new creates a new, empty stack with the given comparison function, which
// may be zero. It returns the new stack or NULL on allocation failure.
OPENSSL_EXPORT _STACK *sk_new(stack_cmp_func comp);
// sk_new_null creates a new, empty stack. It returns the new stack or NULL on
// allocation failure.
OPENSSL_EXPORT _STACK *sk_new_null(void);
// sk_num returns the number of elements in |s|.
OPENSSL_EXPORT size_t sk_num(const _STACK *sk);
// sk_zero resets |sk| to the empty state but does nothing to free the
// individual elements themselves.
OPENSSL_EXPORT void sk_zero(_STACK *sk);
// sk_value returns the |i|th pointer in |sk|, or NULL if |i| is out of
// range.
OPENSSL_EXPORT void *sk_value(const _STACK *sk, size_t i);
// sk_set sets the |i|th pointer in |sk| to |p| and returns |p|. If |i| is out
// of range, it returns NULL.
OPENSSL_EXPORT void *sk_set(_STACK *sk, size_t i, void *p);
// sk_free frees the given stack and array of pointers, but does nothing to
// free the individual elements. Also see |sk_pop_free_ex|.
OPENSSL_EXPORT void sk_free(_STACK *sk);
// sk_pop_free_ex calls |free_func| on each element in the stack and then frees
// the stack itself. Note this corresponds to |sk_FOO_pop_free|. It is named
// |sk_pop_free_ex| as a workaround for existing code calling an older version
// of |sk_pop_free|.
OPENSSL_EXPORT void sk_pop_free_ex(_STACK *sk,
void (*call_free_func)(stack_free_func,
void *),
stack_free_func free_func);
// sk_insert inserts |p| into the stack at index |where|, moving existing
// elements if needed. It returns the length of the new stack, or zero on
// error.
OPENSSL_EXPORT size_t sk_insert(_STACK *sk, void *p, size_t where);
// sk_delete removes the pointer at index |where|, moving other elements down
// if needed. It returns the removed pointer, or NULL if |where| is out of
// range.
OPENSSL_EXPORT void *sk_delete(_STACK *sk, size_t where);
// sk_delete_ptr removes, at most, one instance of |p| from the stack based on
// pointer equality. If an instance of |p| is found then |p| is returned,
// otherwise it returns NULL.
OPENSSL_EXPORT void *sk_delete_ptr(_STACK *sk, const void *p);
// sk_find returns the first value in the stack equal to |p|. If a comparison
// function has been set on the stack, equality is defined by it, otherwise
// pointer equality is used. If the stack is sorted, then a binary search is
// used, otherwise a linear search is performed. If a matching element is found,
// its index is written to
// |*out_index| (if |out_index| is not NULL) and one is returned. Otherwise zero
// is returned.
//
// Note this differs from OpenSSL. The type signature is slightly different, and
// OpenSSL's sk_find will implicitly sort |sk| if it has a comparison function
// defined.
OPENSSL_EXPORT int sk_find(const _STACK *sk, size_t *out_index, const void *p,
int (*call_cmp_func)(stack_cmp_func, const void **,
const void **));
// sk_shift removes and returns the first element in the stack, or returns NULL
// if the stack is empty.
OPENSSL_EXPORT void *sk_shift(_STACK *sk);
// sk_push appends |p| to the stack and returns the length of the new stack, or
// 0 on allocation failure.
OPENSSL_EXPORT size_t sk_push(_STACK *sk, void *p);
// sk_pop returns and removes the last element on the stack, or NULL if the
// stack is empty.
OPENSSL_EXPORT void *sk_pop(_STACK *sk);
// sk_dup performs a shallow copy of a stack and returns the new stack, or NULL
// on error.
OPENSSL_EXPORT _STACK *sk_dup(const _STACK *sk);
// sk_sort sorts the elements of |sk| into ascending order based on the
// comparison function. The stack maintains a |sorted| flag and sorting an
// already sorted stack is a no-op.
OPENSSL_EXPORT void sk_sort(_STACK *sk);
// sk_is_sorted returns one if |sk| is known to be sorted and zero
// otherwise.
OPENSSL_EXPORT int sk_is_sorted(const _STACK *sk);
// sk_set_cmp_func sets the comparison function to be used by |sk| and returns
// the previous one.
OPENSSL_EXPORT stack_cmp_func sk_set_cmp_func(_STACK *sk, stack_cmp_func comp);
// sk_deep_copy performs a copy of |sk| and of each of the non-NULL elements in
// |sk| by using |copy_func|. If an error occurs, |free_func| is used to free
// any copies already made and NULL is returned.
OPENSSL_EXPORT _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);
// Deprecated functions.
// sk_pop_free behaves like |sk_pop_free_ex| but performs an invalid function
// pointer cast. It exists because some existing callers called |sk_pop_free|
// directly.
//
// TODO(davidben): Migrate callers to bssl::UniquePtr and remove this.
OPENSSL_EXPORT void sk_pop_free(_STACK *sk, stack_free_func free_func);
// Defining stack types.
//
// This set of macros is used to emit the typed functions that act on a
// |STACK_OF(T)|.
#if !defined(BORINGSSL_NO_CXX)
extern "C++" {
BSSL_NAMESPACE_BEGIN
namespace internal {
template <typename T>
struct StackTraits {};
}
BSSL_NAMESPACE_END
}
#define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const) \
extern "C++" { \
BSSL_NAMESPACE_BEGIN \
namespace internal { \
template <> \
struct StackTraits<STACK_OF(name)> { \
static constexpr bool kIsStack = true; \
using Type = type; \
static constexpr bool kIsConst = is_const; \
}; \
} \
BSSL_NAMESPACE_END \
}
#else
#define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const)
#endif
#define BORINGSSL_DEFINE_STACK_OF_IMPL(name, ptrtype, constptrtype) \
DECLARE_STACK_OF(name) \
\
typedef void (*stack_##name##_free_func)(ptrtype); \
typedef ptrtype (*stack_##name##_copy_func)(ptrtype); \
typedef int (*stack_##name##_cmp_func)(constptrtype *a, constptrtype *b); \
\
OPENSSL_INLINE void sk_##name##_call_free_func(stack_free_func free_func, \
void *ptr) { \
((stack_##name##_free_func)free_func)((ptrtype)ptr); \
} \
\
OPENSSL_INLINE void *sk_##name##_call_copy_func(stack_copy_func copy_func, \
void *ptr) { \
return (void *)((stack_##name##_copy_func)copy_func)((ptrtype)ptr); \
} \
\
OPENSSL_INLINE int sk_##name##_call_cmp_func( \
stack_cmp_func cmp_func, const void **a, const void **b) { \
constptrtype a_ptr = (constptrtype)*a; \
constptrtype b_ptr = (constptrtype)*b; \
return ((stack_##name##_cmp_func)cmp_func)(&a_ptr, &b_ptr); \
} \
\
OPENSSL_INLINE STACK_OF(name) * \
sk_##name##_new(stack_##name##_cmp_func comp) { \
return (STACK_OF(name) *)sk_new((stack_cmp_func)comp); \
} \
\
OPENSSL_INLINE STACK_OF(name) *sk_##name##_new_null(void) { \
return (STACK_OF(name) *)sk_new_null(); \
} \
\
OPENSSL_INLINE size_t sk_##name##_num(const STACK_OF(name) *sk) { \
return sk_num((const _STACK *)sk); \
} \
\
OPENSSL_INLINE void sk_##name##_zero(STACK_OF(name) *sk) { \
sk_zero((_STACK *)sk); \
} \
\
OPENSSL_INLINE ptrtype sk_##name##_value(const STACK_OF(name) *sk, \
size_t i) { \
return (ptrtype)sk_value((const _STACK *)sk, i); \
} \
\
OPENSSL_INLINE ptrtype sk_##name##_set(STACK_OF(name) *sk, size_t i, \
ptrtype p) { \
return (ptrtype)sk_set((_STACK *)sk, i, (void *)p); \
} \
\
OPENSSL_INLINE void sk_##name##_free(STACK_OF(name) * sk) { \
sk_free((_STACK *)sk); \
} \
\
OPENSSL_INLINE void sk_##name##_pop_free( \
STACK_OF(name) * sk, stack_##name##_free_func free_func) { \
sk_pop_free_ex((_STACK *)sk, sk_##name##_call_free_func, \
(stack_free_func)free_func); \
} \
\
OPENSSL_INLINE size_t sk_##name##_insert(STACK_OF(name) *sk, ptrtype p, \
size_t where) { \
return sk_insert((_STACK *)sk, (void *)p, where); \
} \
\
OPENSSL_INLINE ptrtype sk_##name##_delete(STACK_OF(name) *sk, \
size_t where) { \
return (ptrtype)sk_delete((_STACK *)sk, where); \
} \
\
OPENSSL_INLINE ptrtype sk_##name##_delete_ptr(STACK_OF(name) *sk, \
constptrtype p) { \
return (ptrtype)sk_delete_ptr((_STACK *)sk, (const void *)p); \
} \
\
OPENSSL_INLINE int sk_##name##_find(const STACK_OF(name) *sk, \
size_t * out_index, constptrtype p) { \
return sk_find((const _STACK *)sk, out_index, (const void *)p, \
sk_##name##_call_cmp_func); \
} \
\
OPENSSL_INLINE ptrtype sk_##name##_shift(STACK_OF(name) *sk) { \
return (ptrtype)sk_shift((_STACK *)sk); \
} \
\
OPENSSL_INLINE size_t sk_##name##_push(STACK_OF(name) *sk, ptrtype p) { \
return sk_push((_STACK *)sk, (void *)p); \
} \
\
OPENSSL_INLINE ptrtype sk_##name##_pop(STACK_OF(name) *sk) { \
return (ptrtype)sk_pop((_STACK *)sk); \
} \
\
OPENSSL_INLINE STACK_OF(name) * sk_##name##_dup(const STACK_OF(name) *sk) { \
return (STACK_OF(name) *)sk_dup((const _STACK *)sk); \
} \
\
OPENSSL_INLINE void sk_##name##_sort(STACK_OF(name) *sk) { \
sk_sort((_STACK *)sk); \
} \
\
OPENSSL_INLINE int sk_##name##_is_sorted(const STACK_OF(name) *sk) { \
return sk_is_sorted((const _STACK *)sk); \
} \
\
OPENSSL_INLINE stack_##name##_cmp_func sk_##name##_set_cmp_func( \
STACK_OF(name) *sk, stack_##name##_cmp_func comp) { \
return (stack_##name##_cmp_func)sk_set_cmp_func((_STACK *)sk, \
(stack_cmp_func)comp); \
} \
\
OPENSSL_INLINE STACK_OF(name) * \
sk_##name##_deep_copy(const STACK_OF(name) *sk, \
ptrtype(*copy_func)(ptrtype), \
void (*free_func)(ptrtype)) { \
return (STACK_OF(name) *)sk_deep_copy( \
(const _STACK *)sk, sk_##name##_call_copy_func, \
(stack_copy_func)copy_func, sk_##name##_call_free_func, \
(stack_free_func)free_func); \
}
// DEFINE_NAMED_STACK_OF defines |STACK_OF(name)| to be a stack whose elements
// are |type| *.
#define DEFINE_NAMED_STACK_OF(name, type) \
BORINGSSL_DEFINE_STACK_OF_IMPL(name, type *, const type *) \
BORINGSSL_DEFINE_STACK_TRAITS(name, type, false)
// DEFINE_STACK_OF defines |STACK_OF(type)| to be a stack whose elements are
// |type| *.
#define DEFINE_STACK_OF(type) DEFINE_NAMED_STACK_OF(type, type)
// DEFINE_CONST_STACK_OF defines |STACK_OF(type)| to be a stack whose elements
// are const |type| *.
#define DEFINE_CONST_STACK_OF(type) \
BORINGSSL_DEFINE_STACK_OF_IMPL(type, const type *, const type *) \
BORINGSSL_DEFINE_STACK_TRAITS(type, const type, true)
// DEFINE_SPECIAL_STACK_OF defines |STACK_OF(type)| to be a stack whose elements
// are |type|, where |type| must be a typedef for a pointer.
#define DEFINE_SPECIAL_STACK_OF(type) \
OPENSSL_STATIC_ASSERT(sizeof(type) == sizeof(void *), \
#type " is not a pointer"); \
BORINGSSL_DEFINE_STACK_OF_IMPL(type, type, const type)
typedef char *OPENSSL_STRING;
DEFINE_STACK_OF(void)
DEFINE_SPECIAL_STACK_OF(OPENSSL_STRING)
#if defined(__cplusplus)
} // extern C
#endif
#if !defined(BORINGSSL_NO_CXX)
extern "C++" {
#include <type_traits>
BSSL_NAMESPACE_BEGIN
namespace internal {
// Stacks defined with |DEFINE_CONST_STACK_OF| are freed with |sk_free|.
template <typename Stack>
struct DeleterImpl<
Stack, typename std::enable_if<StackTraits<Stack>::kIsConst>::type> {
static void Free(Stack *sk) { sk_free(reinterpret_cast<_STACK *>(sk)); }
};
// Stacks defined with |DEFINE_STACK_OF| are freed with |sk_pop_free| and the
// corresponding type's deleter.
template <typename Stack>
struct DeleterImpl<
Stack, typename std::enable_if<!StackTraits<Stack>::kIsConst>::type> {
static void Free(Stack *sk) {
// sk_FOO_pop_free is defined by macros and bound by name, so we cannot
// access it from C++ here.
using Type = typename StackTraits<Stack>::Type;
sk_pop_free_ex(reinterpret_cast<_STACK *>(sk),
[](stack_free_func /* unused */, void *ptr) {
DeleterImpl<Type>::Free(reinterpret_cast<Type *>(ptr));
},
nullptr);
}
};
template <typename Stack>
class StackIteratorImpl {
public:
using Type = typename StackTraits<Stack>::Type;
// Iterators must be default-constructable.
StackIteratorImpl() : sk_(nullptr), idx_(0) {}
StackIteratorImpl(const Stack *sk, size_t idx) : sk_(sk), idx_(idx) {}
bool operator==(StackIteratorImpl other) const {
return sk_ == other.sk_ && idx_ == other.idx_;
}
bool operator!=(StackIteratorImpl other) const {
return !(*this == other);
}
Type *operator*() const {
return reinterpret_cast<Type *>(
sk_value(reinterpret_cast<const _STACK *>(sk_), idx_));
}
StackIteratorImpl &operator++(/* prefix */) {
idx_++;
return *this;
}
StackIteratorImpl operator++(int /* postfix */) {
StackIteratorImpl copy(*this);
++(*this);
return copy;
}
private:
const Stack *sk_;
size_t idx_;
};
template <typename Stack>
using StackIterator = typename std::enable_if<StackTraits<Stack>::kIsStack,
StackIteratorImpl<Stack>>::type;
} // namespace internal
// PushToStack pushes |elem| to |sk|. It returns true on success and false on
// allocation failure.
template <typename Stack>
inline
typename std::enable_if<!internal::StackTraits<Stack>::kIsConst, bool>::type
PushToStack(Stack *sk,
UniquePtr<typename internal::StackTraits<Stack>::Type> elem) {
if (!sk_push(reinterpret_cast<_STACK *>(sk), elem.get())) {
return false;
}
// sk_push takes ownership on success.
elem.release();
return true;
}
BSSL_NAMESPACE_END
// Define begin() and end() for stack types so C++ range for loops work.
template <typename Stack>
inline bssl::internal::StackIterator<Stack> begin(const Stack *sk) {
return bssl::internal::StackIterator<Stack>(sk, 0);
}
template <typename Stack>
inline bssl::internal::StackIterator<Stack> end(const Stack *sk) {
return bssl::internal::StackIterator<Stack>(
sk, sk_num(reinterpret_cast<const _STACK *>(sk)));
}
} // extern C++
#endif
#endif // OPENSSL_HEADER_STACK_H