=head1 SYNOPSIS
-=for comment generic
+=for openssl generic
#include <openssl/safestack.h>
Applications can create and use their own stacks by placing any of the macros
described below in a header file. These macros define typesafe inline
functions that wrap around the utility B<OPENSSL_sk_> API.
-In the description here, I<TYPE> is used
-as a placeholder for any of the OpenSSL datatypes, such as I<X509>.
-
-STACK_OF() returns the name for a stack of the specified B<TYPE>.
-DEFINE_STACK_OF() creates set of functions for a stack of B<TYPE>. This
-will mean that type B<TYPE> is stored in each stack, the type is referenced by
-STACK_OF(TYPE) and each function name begins with I<sk_TYPE_>. For example:
-
- TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
-
+In the description here, B<I<TYPE>> is used
+as a placeholder for any of the OpenSSL datatypes, such as B<X509>.
+
+The STACK_OF() macro returns the name for a stack of the specified B<I<TYPE>>.
+This is an opaque pointer to a structure declaration.
+This can be used in every header file that references the stack.
+There are several B<DEFINE...> macros that create static inline functions
+for all of the functions described on this page.
+This should normally be used in one source file, and the stack manipulation
+is wrapped with application-specific functions.
+
+DEFINE_STACK_OF() creates set of functions for a stack of B<I<TYPE>> elements.
+The type is referenced by
+B<STACK_OF>(B<I<TYPE>>) and each function name begins with B<sk_I<TYPE>_>.
DEFINE_STACK_OF_CONST() is identical to DEFINE_STACK_OF() except
-each element is constant. For example:
+each element is constant.
+ /* DEFINE_STACK_OF(TYPE) */
+ TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
+ /* DEFINE_STACK_OF_CONST(TYPE) */
const TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
-DEFINE_SPECIAL_STACK_OF() defines a stack of B<TYPE> but
-each function uses B<FUNCNAME> in the function name. For example:
+DEFINE_SPECIAL_STACK_OF() and DEFINE_SPECIAL_STACK_OF_CONST() are similar
+except B<FUNCNAME> is used in the function names:
+ /* DEFINE_SPECIAL_STACK_OF(TYPE, FUNCNAME) */
TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
-
-DEFINE_SPECIAL_STACK_OF_CONST() is similar except that each element is
-constant:
-
+ /* DEFINE_SPECIAL_STACK_OF(TYPE, FUNCNAME) */
const TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
-sk_TYPE_num() returns the number of elements in B<sk> or -1 if B<sk> is
-B<NULL>.
+B<sk_I<TYPE>_num>() returns the number of elements in I<sk> or -1 if I<sk> is
+NULL.
-sk_TYPE_value() returns element B<idx> in B<sk>, where B<idx> starts at
-zero. If B<idx> is out of range then B<NULL> is returned.
+B<sk_I<TYPE>_value>() returns element I<idx> in I<sk>, where I<idx> starts at
+zero. If I<idx> is out of range then NULL is returned.
-sk_TYPE_new() allocates a new empty stack using comparison function B<compare>.
-If B<compare> is B<NULL> then no comparison function is used. This function is
-equivalent to sk_TYPE_new_reserve(compare, 0).
+B<sk_I<TYPE>_new>() allocates a new empty stack using comparison function
+I<compare>. If I<compare> is NULL then no comparison function is used. This
+function is equivalent to B<sk_I<TYPE>_new_reserve>(I<compare>, 0).
-sk_TYPE_new_null() allocates a new empty stack with no comparison function. This
-function is equivalent to sk_TYPE_new_reserve(NULL, 0).
+B<sk_I<TYPE>_new_null>() allocates a new empty stack with no comparison
+function. This function is equivalent to B<sk_I<TYPE>_new_reserve>(NULL, 0).
-sk_TYPE_reserve() allocates additional memory in the B<sk> structure
-such that the next B<n> calls to sk_TYPE_insert(), sk_TYPE_push()
-or sk_TYPE_unshift() will not fail or cause memory to be allocated
-or reallocated. If B<n> is zero, any excess space allocated in the
-B<sk> structure is freed. On error B<sk> is unchanged.
+B<sk_I<TYPE>_reserve>() allocates additional memory in the I<sk> structure
+such that the next I<n> calls to B<sk_I<TYPE>_insert>(), B<sk_I<TYPE>_push>()
+or B<sk_I<TYPE>_unshift>() will not fail or cause memory to be allocated
+or reallocated. If I<n> is zero, any excess space allocated in the
+I<sk> structure is freed. On error I<sk> is unchanged.
-sk_TYPE_new_reserve() allocates a new stack. The new stack will have additional
-memory allocated to hold B<n> elements if B<n> is positive. The next B<n> calls
-to sk_TYPE_insert(), sk_TYPE_push() or sk_TYPE_unshift() will not fail or cause
-memory to be allocated or reallocated. If B<n> is zero or less than zero, no
-memory is allocated. sk_TYPE_new_reserve() also sets the comparison function
-B<compare> to the newly created stack. If B<compare> is B<NULL> then no
-comparison function is used.
+B<sk_I<TYPE>_new_reserve>() allocates a new stack. The new stack will have
+additional memory allocated to hold I<n> elements if I<n> is positive.
+The next I<n> calls to B<sk_I<TYPE>_insert>(), B<sk_I<TYPE>_push>() or
+B<sk_I<TYPE>_unshift>() will not fail or cause memory to be allocated or
+reallocated. If I<n> is zero or less than zero, no memory is allocated.
+B<sk_I<TYPE>_new_reserve>() also sets the comparison function I<compare>
+to the newly created stack. If I<compare> is NULL then no comparison
+function is used.
-sk_TYPE_set_cmp_func() sets the comparison function of B<sk> to B<compare>.
-The previous comparison function is returned or B<NULL> if there was
-no previous comparison function.
+B<sk_I<TYPE>_set_cmp_func>() sets the comparison function of I<sk> to
+I<compare>. The previous comparison function is returned or NULL if there
+was no previous comparison function.
-sk_TYPE_free() frees up the B<sk> structure. It does B<not> free up any
-elements of B<sk>. After this call B<sk> is no longer valid.
+B<sk_I<TYPE>_free>() frees up the I<sk> structure. It does I<not> free up any
+elements of I<sk>. After this call I<sk> is no longer valid.
-sk_TYPE_zero() sets the number of elements in B<sk> to zero. It does not free
-B<sk> so after this call B<sk> is still valid.
+B<sk_I<TYPE>_zero>() sets the number of elements in I<sk> to zero. It does not
+free I<sk> so after this call I<sk> is still valid.
-sk_TYPE_pop_free() frees up all elements of B<sk> and B<sk> itself. The
+B<sk_I<TYPE>_pop_free>() frees up all elements of I<sk> and I<sk> itself. The
free function freefunc() is called on each element to free it.
-sk_TYPE_delete() deletes element B<i> from B<sk>. It returns the deleted
-element or B<NULL> if B<i> is out of range.
+B<sk_I<TYPE>_delete>() deletes element I<i> from I<sk>. It returns the deleted
+element or NULL if I<i> is out of range.
-sk_TYPE_delete_ptr() deletes element matching B<ptr> from B<sk>. It returns
-
the deleted element or B<NULL> if no element matching B<ptr> was found.
+B<sk_I<TYPE>_delete_ptr>() deletes element matching I<ptr> from I<sk>. It
+
returns the deleted element or NULL if no element matching I<ptr> was found.
-sk_TYPE_insert() inserts B<ptr> into B<sk> at position B<idx>. Any existing
-elements at or after B<idx> are moved downwards. If B<idx> is out of range
-the new element is appended to B<sk>. sk_TYPE_insert() either returns the
-number of elements in B<sk> after the new element is inserted or zero if
-an error (such as memory allocation failure) occurred.
+B<sk_I<TYPE>_insert>() inserts I<ptr> into I<sk> at position I<idx>. Any
+existing elements at or after I<idx> are moved downwards. If I<idx> is out
+of range the new element is appended to I<sk>. B<sk_I<TYPE>_insert>() either
+returns the number of elements in I<sk> after the new element is inserted or
+zero if an error (such as memory allocation failure) occurred.
-sk_TYPE_push() appends B<ptr> to B<sk> it is equivalent to:
+B<sk_I<TYPE>_push>() appends I<ptr> to I<sk> it is equivalent to:
sk_TYPE_insert(sk, ptr, -1);
-sk_TYPE_unshift() inserts B<ptr> at the start of B<sk> it is equivalent to:
+B<sk_I<TYPE>_unshift>() inserts I<ptr> at the start of I<sk> it is equivalent
+to:
sk_TYPE_insert(sk, ptr, 0);
-sk_TYPE_pop() returns and removes the last element from B<sk>.
+B<sk_I<TYPE>_pop>() returns and removes the last element from I<sk>.
-sk_TYPE_shift() returns and removes the first element from B<sk>.
+B<sk_I<TYPE>_shift>() returns and removes the first element from I<sk>.
-
sk_TYPE_set() sets element B<idx> of B<sk> to B<ptr> replacing the current
-element. The new element value is returned or B<NULL> if an error occurred:
-this will only happen if B<sk> is B<NULL> or B<idx> is out of range.
+
B<sk_I<TYPE>_set>() sets element I<idx> of I<sk> to I<ptr> replacing the current
+element. The new element value is returned or NULL if an error occurred:
+this will only happen if I<sk> is NULL or I<idx> is out of range.
-
sk_TYPE_find() searches B<sk> for the element B<ptr>. In the case
+
B<sk_I<TYPE>_find>() searches I<sk> for the element I<ptr>. In the case
where no comparison function has been specified, the function performs
-a linear search for a pointer equal to
B<ptr>. The index of the first
+a linear search for a pointer equal to
I<ptr>. The index of the first
matching element is returned or B<-1> if there is no match. In the case
-where a comparison function has been specified, B<sk> is sorted then
-sk_TYPE_find() returns the index of a matching element or B<-1> if there
+where a comparison function has been specified, I<sk> is sorted then
+B<sk_I<TYPE>_find>() returns the index of a matching element or B<-1> if there
is no match. Note that, in this case, the matching element returned is
not guaranteed to be the first; the comparison function will usually
compare the values pointed to rather than the pointers themselves and
-the order of elements in B<sk> could change.
+the order of elements in I<sk> could change.
-sk_TYPE_find_ex() operates like sk_TYPE_find() except when a comparison
-function has been specified and no matching element is found. Instead
-of returning B<-1>, sk_TYPE_find_ex() returns the index of the element
-e
ither before or after the location where B<ptr> would be if it were
-present in B<sk>.
+B<sk_I<TYPE>_find_ex>() operates like B<sk_I<TYPE>_find>() except when a
+comparison function has been specified and no matching element is found.
+Instead of returning B<-1>, B<sk_I<TYPE>_find_ex>() returns the index of the
+e
lement either before or after the location where I<ptr> would be if it were
+present in I<sk>.
-sk_TYPE_sort() sorts B<sk> using the supplied comparison function.
+B<sk_I<TYPE>_sort>() sorts I<sk> using the supplied comparison function.
-sk_TYPE_is_sorted() returns B<1> if B<sk> is sorted and B<0> otherwise.
+B<sk_I<TYPE>_is_sorted>() returns B<1> if I<sk> is sorted and B<0> otherwise.
-sk_TYPE_dup() returns a copy of B<sk>. Note the pointers in the copy
+B<sk_I<TYPE>_dup>() returns a copy of I<sk>. Note the pointers in the copy
are identical to the original.
-sk_TYPE_deep_copy() returns a new stack where each element has been copied.
-Copying is performed by the supplied copyfunc() and freeing by freefunc(). The
-function freefunc() is only called if an error occurs.
+B<sk_I<TYPE>_deep_copy>() returns a new stack where each element has been
+copied. Copying is performed by the supplied copyfunc() and freeing by
+freefunc(). The function freefunc() is only called if an error occurs.
=head1 NOTES
Care should be taken when accessing stacks in multi-threaded environments.
-Any operation which increases the size of a stack such as sk_TYPE_insert() or
-sk_push() can "grow" the size of an internal array and cause race conditions
-if the same stack is accessed in a different thread. Operations such as
-sk_find() and sk_sort() can also reorder the stack.
+Any operation which increases the size of a stack such as B<sk_I<TYPE>_insert>()
+or B<sk_I<TYPE>_push>() can "grow" the size of an internal array and cause race
+conditions if the same stack is accessed in a different thread. Operations such
+as B<sk_I<TYPE>_find>() and B<sk_I<TYPE>_sort>() can also reorder the stack.
Any comparison function supplied should use a metric suitable
for use in a binary search operation. That is it should return zero, a
-positive or negative value if
B<a> is equal to, greater than
-or less than B<b> respectively.
+positive or negative value if
I<a> is equal to, greater than
+or less than I<b> respectively.
Care should be taken when checking the return values of the functions
-sk_TYPE_find() and sk_TYPE_find_ex(). They return an index to the
+B<sk_I<TYPE>_find>() and B<sk_I<TYPE>_find_ex>(). They return an index to the
matching element. In particular B<0> indicates a matching first element.
A failed search is indicated by a B<-1> return value.
=head1 RETURN VALUES
-sk_TYPE_num() returns the number of elements in the stack or B<-1> if the
-passed stack is B<NULL>.
+B<sk_I<TYPE>_num>() returns the number of elements in the stack or B<-1> if the
+passed stack is NULL.
-sk_TYPE_value() returns a pointer to a stack element or B<NULL> if the
+B<sk_I<TYPE>_value>() returns a pointer to a stack element or NULL if the
index is out of range.
-sk_TYPE_new(), sk_TYPE_new_null() and sk_TYPE_new_reserve() return an empty
-stack or B<NULL> if an error occurs.
+B<sk_I<TYPE>_new>(), B<sk_I<TYPE>_new_null>() and B<sk_I<TYPE>_new_reserve>()
+return an empty stack or NULL if an error occurs.
-sk_TYPE_reserve() returns B<1> on successful allocation of the required memory
-or B<0> on error.
+B<sk_I<TYPE>_reserve>() returns B<1> on successful allocation of the required
+memory or B<0> on error.
-sk_TYPE_set_cmp_func() returns the old comparison function or B<NULL> if
+B<sk_I<TYPE>_set_cmp_func>() returns the old comparison function or NULL if
there was no old comparison function.
-sk_TYPE_free(), sk_TYPE_zero(), sk_TYPE_pop_free() and sk_TYPE_sort() do
-not return values.
+B<sk_I<TYPE>_free>(), B<sk_I<TYPE>_zero>(), B<sk_I<TYPE>_pop_free>() and
+B<sk_I<TYPE>_sort>() do not return values.
-sk_TYPE_pop(), sk_TYPE_shift(), sk_TYPE_delete() and sk_TYPE_delete_ptr()
-return a pointer to the deleted element or B<NULL> on error.
+B<sk_I<TYPE>_pop>(), B<sk_I<TYPE>_shift>(), B<sk_I<TYPE>_delete>() and
+B<sk_I<TYPE>_delete_ptr>() return a pointer to the deleted element or NULL
+on error.
-sk_TYPE_insert(), sk_TYPE_push() and sk_TYPE_unshift() return the total
-number of elements in the stack and 0 if an error occurred.
+B<sk_I<TYPE>_insert>(), B<sk_I<TYPE>_push>() and B<sk_I<TYPE>_unshift>() return
+the total number of elements in the stack and 0 if an error occurred.
-sk_TYPE_set() returns a pointer to the replacement element or B<NULL> on
+B<sk_I<TYPE>_set>() returns a pointer to the replacement element or NULL on
error.
-sk_TYPE_find() and sk_TYPE_find_ex() return an index to the found element
-or B<-1> on error.
+B<sk_I<TYPE>_find>() and B<sk_I<TYPE>_find_ex>() return an index to the found
+element or B<-1> on error.
-sk_TYPE_is_sorted() returns B<1> if the stack is sorted and B<0> if it is
+B<sk_I<TYPE>_is_sorted>() returns B<1> if the stack is sorted and B<0> if it is
not.
-sk_TYPE_dup() and sk_TYPE_deep_copy() return a pointer to the copy of the
-stack.
+B<sk_I<TYPE>_dup>() and B<sk_I<TYPE>_deep_copy>() return a pointer to the copy
+of the stack.
=head1 HISTORY
Before OpenSSL 1.1.0, this was implemented via macros and not inline functions
and was not a public API.
-sk_TYPE_reserve() and sk_TYPE_new_reserve() were added in OpenSSL 1.1.1.
+B<sk_I<TYPE>_reserve>() and B<sk_I<TYPE>_new_reserve>() were added in OpenSSL
+1.1.1.
=head1 COPYRIGHT
-Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
projects / openssl.git / blobdiff