boringssl/include/openssl/stack.h
David Benjamin ec783839be Make ranged for loops work with STACK_OF(T).
My original plan here was to make STACK_OF(T) expand to a template so
the inner type were extractable. Unfortunately, we cannot sanely make
STACK_OF(T) expand to a different type in C and C++ even across
compilation units because UBSan sometimes explodes. This is nuts, but so
it goes.

Instead, use StackTraits to extract the STACK_OF(T) parameters and
define an iterator type.

Bug: 189
Change-Id: I64f5173b34b723ec471f7a355ff46b04f161386a
Reviewed-on: https://boringssl-review.googlesource.com/18467
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
2017-07-26 22:02:00 +00:00

471 lines
22 KiB
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.] */
#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_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. */
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|. */
OPENSSL_EXPORT void sk_free(_STACK *sk);
/* sk_pop_free calls |free_func| on each element in the stack and then frees
* the stack itself. */
OPENSSL_EXPORT void sk_pop_free(_STACK *sk, void (*free_func)(void *));
/* 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, void *p);
/* sk_find returns the first value in the stack equal to |p|. If a comparison
* function has been set on the stack, then equality is defined by it and the
* stack will be sorted if need be so that a binary search can be used.
* Otherwise pointer equality is used. 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. */
OPENSSL_EXPORT int sk_find(_STACK *sk, size_t *out_index, void *p);
/* 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 *(*copy_func)(void *),
void (*free_func)(void *));
/* 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++" {
namespace bssl {
namespace internal {
template <typename T>
struct StackTraits {};
}
}
}
#define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const) \
extern "C++" { \
namespace bssl { \
namespace internal { \
template <> \
struct StackTraits<STACK_OF(name)> { \
static constexpr bool kIsStack = true; \
using Type = type; \
static constexpr bool kIsConst = is_const; \
}; \
} \
} \
}
#else
#define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const)
#endif
/* Stack functions must be tagged unused to support file-local stack types.
* Clang's -Wunused-function only allows unused static inline functions if they
* are defined in a header. */
#define BORINGSSL_DEFINE_STACK_OF_IMPL(name, ptrtype, constptrtype) \
DECLARE_STACK_OF(name); \
\
typedef int (*stack_##name##_cmp_func)(constptrtype *a, constptrtype *b); \
\
static inline OPENSSL_UNUSED STACK_OF(name) * \
sk_##name##_new(stack_##name##_cmp_func comp) { \
return (STACK_OF(name) *)sk_new((stack_cmp_func)comp); \
} \
\
static inline OPENSSL_UNUSED STACK_OF(name) *sk_##name##_new_null(void) { \
return (STACK_OF(name) *)sk_new_null(); \
} \
\
static inline OPENSSL_UNUSED size_t sk_##name##_num( \
const STACK_OF(name) *sk) { \
return sk_num((const _STACK *)sk); \
} \
\
static inline OPENSSL_UNUSED void sk_##name##_zero(STACK_OF(name) *sk) { \
sk_zero((_STACK *)sk); \
} \
\
static inline OPENSSL_UNUSED ptrtype sk_##name##_value( \
const STACK_OF(name) *sk, size_t i) { \
return (ptrtype)sk_value((const _STACK *)sk, i); \
} \
\
static inline OPENSSL_UNUSED ptrtype sk_##name##_set(STACK_OF(name) *sk, \
size_t i, ptrtype p) { \
return (ptrtype)sk_set((_STACK *)sk, i, (void *)p); \
} \
\
static inline OPENSSL_UNUSED void sk_##name##_free(STACK_OF(name) *sk) { \
sk_free((_STACK *)sk); \
} \
\
static inline OPENSSL_UNUSED void sk_##name##_pop_free( \
STACK_OF(name) *sk, void (*free_func)(ptrtype p)) { \
sk_pop_free((_STACK *)sk, (void (*)(void *))free_func); \
} \
\
static inline OPENSSL_UNUSED size_t sk_##name##_insert( \
STACK_OF(name) *sk, ptrtype p, size_t where) { \
return sk_insert((_STACK *)sk, (void *)p, where); \
} \
\
static inline OPENSSL_UNUSED ptrtype sk_##name##_delete(STACK_OF(name) *sk, \
size_t where) { \
return (ptrtype)sk_delete((_STACK *)sk, where); \
} \
\
static inline OPENSSL_UNUSED ptrtype sk_##name##_delete_ptr( \
STACK_OF(name) *sk, ptrtype p) { \
return (ptrtype)sk_delete_ptr((_STACK *)sk, (void *)p); \
} \
\
static inline OPENSSL_UNUSED int sk_##name##_find( \
STACK_OF(name) *sk, size_t *out_index, ptrtype p) { \
return sk_find((_STACK *)sk, out_index, (void *)p); \
} \
\
static inline OPENSSL_UNUSED ptrtype sk_##name##_shift(STACK_OF(name) *sk) { \
return (ptrtype)sk_shift((_STACK *)sk); \
} \
\
static inline OPENSSL_UNUSED size_t sk_##name##_push(STACK_OF(name) *sk, \
ptrtype p) { \
return sk_push((_STACK *)sk, (void *)p); \
} \
\
static inline OPENSSL_UNUSED ptrtype sk_##name##_pop(STACK_OF(name) *sk) { \
return (ptrtype)sk_pop((_STACK *)sk); \
} \
\
static inline OPENSSL_UNUSED STACK_OF(name) * \
sk_##name##_dup(const STACK_OF(name) *sk) { \
return (STACK_OF(name) *)sk_dup((const _STACK *)sk); \
} \
\
static inline OPENSSL_UNUSED void sk_##name##_sort(STACK_OF(name) *sk) { \
sk_sort((_STACK *)sk); \
} \
\
static inline OPENSSL_UNUSED int sk_##name##_is_sorted( \
const STACK_OF(name) *sk) { \
return sk_is_sorted((const _STACK *)sk); \
} \
\
static inline OPENSSL_UNUSED 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); \
} \
\
static inline OPENSSL_UNUSED 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((_STACK *)sk, \
(void *(*)(void *))copy_func, \
(void (*)(void *))free_func); \
}
/* DEFINE_STACK_OF defines |STACK_OF(type)| to be a stack whose elements are
* |type| *. */
#define DEFINE_STACK_OF(type) \
BORINGSSL_DEFINE_STACK_OF_IMPL(type, type *, const type *) \
BORINGSSL_DEFINE_STACK_TRAITS(type, type, false)
/* 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_COMPILE_ASSERT(sizeof(type) == sizeof(void *), \
special_stack_of_non_pointer_##type); \
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>
namespace bssl {
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_pop_free(
reinterpret_cast<_STACK *>(sk),
reinterpret_cast<void (*)(void *)>(
DeleterImpl<typename StackTraits<Stack>::Type>::Free));
}
};
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
} // namespace bssl
// Define begin() and end() for stack types so C++ range for loops work.
template <typename Stack>
static inline bssl::internal::StackIterator<Stack> begin(const Stack *sk) {
return bssl::internal::StackIterator<Stack>(sk, 0);
}
template <typename Stack>
static 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 */