xref: /aosp_15_r20/external/boringssl/src/include/openssl/stack.h (revision 8fb009dc861624b67b6cdb62ea21f0f22d0c584b)
1 /* Copyright (C) 1995-1998 Eric Young ([email protected])
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young ([email protected]).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson ([email protected]).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young ([email protected])"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson ([email protected])"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.] */
56 
57 #ifndef OPENSSL_HEADER_STACK_H
58 #define OPENSSL_HEADER_STACK_H
59 
60 #include <openssl/base.h>
61 
62 #if defined(__cplusplus)
63 extern "C" {
64 #endif
65 
66 
67 // A stack, in OpenSSL, is an array of pointers. They are the most commonly
68 // used collection object.
69 //
70 // This file defines macros for type-safe use of the stack functions. A stack
71 // type is named like |STACK_OF(FOO)| and is accessed with functions named
72 // like |sk_FOO_*|. Note the stack will typically contain /pointers/ to |FOO|.
73 //
74 // The |DECLARE_STACK_OF| macro makes |STACK_OF(FOO)| available, and
75 // |DEFINE_STACK_OF| makes the corresponding functions available.
76 
77 
78 // Defining stacks.
79 
80 // STACK_OF expands to the stack type for |type|.
81 #define STACK_OF(type) struct stack_st_##type
82 
83 // DECLARE_STACK_OF declares the |STACK_OF(type)| type. It does not make the
84 // corresponding |sk_type_*| functions available. This macro should be used in
85 // files which only need the type.
86 #define DECLARE_STACK_OF(type) STACK_OF(type);
87 
88 // DEFINE_NAMED_STACK_OF defines |STACK_OF(name)| to be a stack whose elements
89 // are |type| *. This macro makes the |sk_name_*| functions available.
90 //
91 // It is not necessary to use |DECLARE_STACK_OF| in files which use this macro.
92 #define DEFINE_NAMED_STACK_OF(name, type)                    \
93   BORINGSSL_DEFINE_STACK_OF_IMPL(name, type *, const type *) \
94   BORINGSSL_DEFINE_STACK_TRAITS(name, type, false)
95 
96 // DEFINE_STACK_OF defines |STACK_OF(type)| to be a stack whose elements are
97 // |type| *. This macro makes the |sk_type_*| functions available.
98 //
99 // It is not necessary to use |DECLARE_STACK_OF| in files which use this macro.
100 #define DEFINE_STACK_OF(type) DEFINE_NAMED_STACK_OF(type, type)
101 
102 // DEFINE_CONST_STACK_OF defines |STACK_OF(type)| to be a stack whose elements
103 // are const |type| *. This macro makes the |sk_type_*| functions available.
104 //
105 // It is not necessary to use |DECLARE_STACK_OF| in files which use this macro.
106 #define DEFINE_CONST_STACK_OF(type)                                \
107   BORINGSSL_DEFINE_STACK_OF_IMPL(type, const type *, const type *) \
108   BORINGSSL_DEFINE_STACK_TRAITS(type, const type, true)
109 
110 
111 // Using stacks.
112 //
113 // After the |DEFINE_STACK_OF| macro is used, the following functions are
114 // available.
115 
116 #if 0  // Sample
117 
118 // sk_SAMPLE_free_func is a callback to free an element in a stack.
119 typedef void (*sk_SAMPLE_free_func)(SAMPLE *);
120 
121 // sk_SAMPLE_copy_func is a callback to copy an element in a stack. It should
122 // return the copy or NULL on error.
123 typedef SAMPLE *(*sk_SAMPLE_copy_func)(const SAMPLE *);
124 
125 // sk_SAMPLE_cmp_func is a callback to compare |*a| to |*b|. It should return a
126 // value < 0, 0, or > 0 if |*a| is less than, equal to, or greater than |*b|,
127 // respectively.  Note the extra indirection - the function is given a pointer
128 // to a pointer to the element. This is the |qsort|/|bsearch| comparison
129 // function applied to an array of |SAMPLE*|.
130 typedef int (*sk_SAMPLE_cmp_func)(const SAMPLE *const *a,
131                                   const SAMPLE *const *b);
132 
133 // sk_SAMPLE_new creates a new, empty stack with the given comparison function,
134 // which may be NULL. It returns the new stack or NULL on allocation failure.
135 STACK_OF(SAMPLE) *sk_SAMPLE_new(sk_SAMPLE_cmp_func comp);
136 
137 // sk_SAMPLE_new_null creates a new, empty stack. It returns the new stack or
138 // NULL on allocation failure.
139 STACK_OF(SAMPLE) *sk_SAMPLE_new_null(void);
140 
141 // sk_SAMPLE_num returns the number of elements in |sk|. It is safe to cast this
142 // value to |int|. |sk| is guaranteed to have at most |INT_MAX| elements. If
143 // |sk| is NULL, it is treated as the empty list and this function returns zero.
144 size_t sk_SAMPLE_num(const STACK_OF(SAMPLE) *sk);
145 
146 // sk_SAMPLE_zero resets |sk| to the empty state but does nothing to free the
147 // individual elements themselves.
148 void sk_SAMPLE_zero(STACK_OF(SAMPLE) *sk);
149 
150 // sk_SAMPLE_value returns the |i|th pointer in |sk|, or NULL if |i| is out of
151 // range. If |sk| is NULL, it is treated as an empty list and the function
152 // returns NULL.
153 SAMPLE *sk_SAMPLE_value(const STACK_OF(SAMPLE) *sk, size_t i);
154 
155 // sk_SAMPLE_set sets the |i|th pointer in |sk| to |p| and returns |p|. If |i|
156 // is out of range, it returns NULL.
157 SAMPLE *sk_SAMPLE_set(STACK_OF(SAMPLE) *sk, size_t i, SAMPLE *p);
158 
159 // sk_SAMPLE_free frees |sk|, but does nothing to free the individual elements.
160 // Use |sk_SAMPLE_pop_free| to also free the elements.
161 void sk_SAMPLE_free(STACK_OF(SAMPLE) *sk);
162 
163 // sk_SAMPLE_pop_free calls |free_func| on each element in |sk| and then
164 // frees the stack itself.
165 void sk_SAMPLE_pop_free(STACK_OF(SAMPLE) *sk, sk_SAMPLE_free_func free_func);
166 
167 // sk_SAMPLE_insert inserts |p| into the stack at index |where|, moving existing
168 // elements if needed. It returns the length of the new stack, or zero on
169 // error.
170 size_t sk_SAMPLE_insert(STACK_OF(SAMPLE) *sk, SAMPLE *p, size_t where);
171 
172 // sk_SAMPLE_delete removes the pointer at index |where|, moving other elements
173 // down if needed. It returns the removed pointer, or NULL if |where| is out of
174 // range.
175 SAMPLE *sk_SAMPLE_delete(STACK_OF(SAMPLE) *sk, size_t where);
176 
177 // sk_SAMPLE_delete_ptr removes, at most, one instance of |p| from |sk| based on
178 // pointer equality. If an instance of |p| is found then |p| is returned,
179 // otherwise it returns NULL.
180 SAMPLE *sk_SAMPLE_delete_ptr(STACK_OF(SAMPLE) *sk, const SAMPLE *p);
181 
182 // sk_SAMPLE_delete_if_func is the callback function for |sk_SAMPLE_delete_if|.
183 // It should return one to remove |p| and zero to keep it.
184 typedef int (*sk_SAMPLE_delete_if_func)(SAMPLE *p, void *data);
185 
186 // sk_SAMPLE_delete_if calls |func| with each element of |sk| and removes the
187 // entries where |func| returned one. This function does not free or return
188 // removed pointers so, if |sk| owns its contents, |func| should release the
189 // pointers prior to returning one.
190 void sk_SAMPLE_delete_if(STACK_OF(SAMPLE) *sk, sk_SAMPLE_delete_if_func func,
191                          void *data);
192 
193 // sk_SAMPLE_find find the first value in |sk| equal to |p|. |sk|'s comparison
194 // function determines equality, or pointer equality if |sk| has no comparison
195 // function.
196 //
197 // If the stack is sorted (see |sk_SAMPLE_sort|), this function uses a binary
198 // search. Otherwise it performs a linear search. If it finds a matching
199 // element, it writes the index to |*out_index| (if |out_index| is not NULL) and
200 // returns one. Otherwise, it returns zero. If |sk| is NULL, it is treated as
201 // the empty list and the function returns zero.
202 //
203 // Note this differs from OpenSSL. The type signature is slightly different, and
204 // OpenSSL's version will implicitly sort |sk| if it has a comparison function
205 // defined.
206 int sk_SAMPLE_find(const STACK_OF(SAMPLE) *sk, size_t *out_index,
207                    const SAMPLE *p);
208 
209 // sk_SAMPLE_shift removes and returns the first element in |sk|, or NULL if
210 // |sk| is empty.
211 SAMPLE *sk_SAMPLE_shift(STACK_OF(SAMPLE) *sk);
212 
213 // sk_SAMPLE_push appends |p| to |sk| and returns the length of the new stack,
214 // or 0 on allocation failure.
215 size_t sk_SAMPLE_push(STACK_OF(SAMPLE) *sk, SAMPLE *p);
216 
217 // sk_SAMPLE_pop removes and returns the last element of |sk|, or NULL if |sk|
218 // is empty.
219 SAMPLE *sk_SAMPLE_pop(STACK_OF(SAMPLE) *sk);
220 
221 // sk_SAMPLE_dup performs a shallow copy of a stack and returns the new stack,
222 // or NULL on error. Use |sk_SAMPLE_deep_copy| to also copy the elements.
223 STACK_OF(SAMPLE) *sk_SAMPLE_dup(const STACK_OF(SAMPLE) *sk);
224 
225 // sk_SAMPLE_sort sorts the elements of |sk| into ascending order based on the
226 // comparison function. The stack maintains a "sorted" flag and sorting an
227 // already sorted stack is a no-op.
228 void sk_SAMPLE_sort(STACK_OF(SAMPLE) *sk);
229 
230 // sk_SAMPLE_is_sorted returns one if |sk| is known to be sorted and zero
231 // otherwise.
232 int sk_SAMPLE_is_sorted(const STACK_OF(SAMPLE) *sk);
233 
234 // sk_SAMPLE_set_cmp_func sets the comparison function to be used by |sk| and
235 // returns the previous one.
236 sk_SAMPLE_cmp_func sk_SAMPLE_set_cmp_func(STACK_OF(SAMPLE) *sk,
237                                           sk_SAMPLE_cmp_func comp);
238 
239 // sk_SAMPLE_deep_copy performs a copy of |sk| and of each of the non-NULL
240 // elements in |sk| by using |copy_func|. If an error occurs, it calls
241 // |free_func| to free any copies already made and returns NULL.
242 STACK_OF(SAMPLE) *sk_SAMPLE_deep_copy(const STACK_OF(SAMPLE) *sk,
243                                       sk_SAMPLE_copy_func copy_func,
244                                       sk_SAMPLE_free_func free_func);
245 
246 #endif  // Sample
247 
248 
249 // Private functions.
250 //
251 // The |sk_*| functions generated above are implemented internally using the
252 // type-erased functions below. Callers should use the typed wrappers instead.
253 // When using the type-erased functions, callers are responsible for ensuring
254 // the underlying types are correct. Casting pointers to the wrong types will
255 // result in memory errors.
256 
257 // OPENSSL_sk_free_func is a function that frees an element in a stack. Note its
258 // actual type is void (*)(T *) for some T. Low-level |sk_*| functions will be
259 // passed a type-specific wrapper to call it correctly.
260 typedef void (*OPENSSL_sk_free_func)(void *ptr);
261 
262 // OPENSSL_sk_copy_func is a function that copies an element in a stack. Note
263 // its actual type is T *(*)(const T *) for some T. Low-level |sk_*| functions
264 // will be passed a type-specific wrapper to call it correctly.
265 typedef void *(*OPENSSL_sk_copy_func)(const void *ptr);
266 
267 // OPENSSL_sk_cmp_func is a comparison function that returns a value < 0, 0 or >
268 // 0 if |*a| is less than, equal to or greater than |*b|, respectively.  Note
269 // the extra indirection - the function is given a pointer to a pointer to the
270 // element. This differs from the usual qsort/bsearch comparison function.
271 //
272 // Note its actual type is |int (*)(const T *const *a, const T *const *b)|.
273 // Low-level |sk_*| functions will be passed a type-specific wrapper to call it
274 // correctly.
275 typedef int (*OPENSSL_sk_cmp_func)(const void *const *a, const void *const *b);
276 
277 // OPENSSL_sk_delete_if_func is the generic version of
278 // |sk_SAMPLE_delete_if_func|.
279 typedef int (*OPENSSL_sk_delete_if_func)(void *obj, void *data);
280 
281 // The following function types call the above type-erased signatures with the
282 // true types.
283 typedef void (*OPENSSL_sk_call_free_func)(OPENSSL_sk_free_func, void *);
284 typedef void *(*OPENSSL_sk_call_copy_func)(OPENSSL_sk_copy_func, const void *);
285 typedef int (*OPENSSL_sk_call_cmp_func)(OPENSSL_sk_cmp_func, const void *,
286                                         const void *);
287 typedef int (*OPENSSL_sk_call_delete_if_func)(OPENSSL_sk_delete_if_func, void *,
288                                               void *);
289 
290 // An OPENSSL_STACK contains an array of pointers. It is not designed to be used
291 // directly, rather the wrapper macros should be used.
292 typedef struct stack_st OPENSSL_STACK;
293 
294 // The following are raw stack functions. They implement the corresponding typed
295 // |sk_SAMPLE_*| functions generated by |DEFINE_STACK_OF|. Callers shouldn't be
296 // using them. Rather, callers should use the typed functions.
297 OPENSSL_EXPORT OPENSSL_STACK *OPENSSL_sk_new(OPENSSL_sk_cmp_func comp);
298 OPENSSL_EXPORT OPENSSL_STACK *OPENSSL_sk_new_null(void);
299 OPENSSL_EXPORT size_t OPENSSL_sk_num(const OPENSSL_STACK *sk);
300 OPENSSL_EXPORT void OPENSSL_sk_zero(OPENSSL_STACK *sk);
301 OPENSSL_EXPORT void *OPENSSL_sk_value(const OPENSSL_STACK *sk, size_t i);
302 OPENSSL_EXPORT void *OPENSSL_sk_set(OPENSSL_STACK *sk, size_t i, void *p);
303 OPENSSL_EXPORT void OPENSSL_sk_free(OPENSSL_STACK *sk);
304 OPENSSL_EXPORT void OPENSSL_sk_pop_free_ex(
305     OPENSSL_STACK *sk, OPENSSL_sk_call_free_func call_free_func,
306     OPENSSL_sk_free_func free_func);
307 OPENSSL_EXPORT size_t OPENSSL_sk_insert(OPENSSL_STACK *sk, void *p,
308                                         size_t where);
309 OPENSSL_EXPORT void *OPENSSL_sk_delete(OPENSSL_STACK *sk, size_t where);
310 OPENSSL_EXPORT void *OPENSSL_sk_delete_ptr(OPENSSL_STACK *sk, const void *p);
311 OPENSSL_EXPORT void OPENSSL_sk_delete_if(
312     OPENSSL_STACK *sk, OPENSSL_sk_call_delete_if_func call_func,
313     OPENSSL_sk_delete_if_func func, void *data);
314 OPENSSL_EXPORT int OPENSSL_sk_find(const OPENSSL_STACK *sk, size_t *out_index,
315                                    const void *p,
316                                    OPENSSL_sk_call_cmp_func call_cmp_func);
317 OPENSSL_EXPORT void *OPENSSL_sk_shift(OPENSSL_STACK *sk);
318 OPENSSL_EXPORT size_t OPENSSL_sk_push(OPENSSL_STACK *sk, void *p);
319 OPENSSL_EXPORT void *OPENSSL_sk_pop(OPENSSL_STACK *sk);
320 OPENSSL_EXPORT OPENSSL_STACK *OPENSSL_sk_dup(const OPENSSL_STACK *sk);
321 OPENSSL_EXPORT void OPENSSL_sk_sort(OPENSSL_STACK *sk,
322                                     OPENSSL_sk_call_cmp_func call_cmp_func);
323 OPENSSL_EXPORT int OPENSSL_sk_is_sorted(const OPENSSL_STACK *sk);
324 OPENSSL_EXPORT OPENSSL_sk_cmp_func
325 OPENSSL_sk_set_cmp_func(OPENSSL_STACK *sk, OPENSSL_sk_cmp_func comp);
326 OPENSSL_EXPORT OPENSSL_STACK *OPENSSL_sk_deep_copy(
327     const OPENSSL_STACK *sk, OPENSSL_sk_call_copy_func call_copy_func,
328     OPENSSL_sk_copy_func copy_func, OPENSSL_sk_call_free_func call_free_func,
329     OPENSSL_sk_free_func free_func);
330 
331 
332 // Deprecated private functions (hidden).
333 //
334 // TODO(crbug.com/boringssl/499): Migrate callers to the typed wrappers, or at
335 // least the new names and remove the old ones.
336 //
337 // TODO(b/290792019, b/290785937): Ideally these would at least be inline
338 // functions, so we do not squat the symbols.
339 
340 typedef OPENSSL_STACK _STACK;
341 
342 // The following functions call the corresponding |OPENSSL_sk_*| function.
343 OPENSSL_EXPORT OPENSSL_DEPRECATED OPENSSL_STACK *sk_new_null(void);
344 OPENSSL_EXPORT OPENSSL_DEPRECATED size_t sk_num(const OPENSSL_STACK *sk);
345 OPENSSL_EXPORT OPENSSL_DEPRECATED void *sk_value(const OPENSSL_STACK *sk,
346                                                  size_t i);
347 OPENSSL_EXPORT OPENSSL_DEPRECATED void sk_free(OPENSSL_STACK *sk);
348 OPENSSL_EXPORT OPENSSL_DEPRECATED size_t sk_push(OPENSSL_STACK *sk, void *p);
349 OPENSSL_EXPORT OPENSSL_DEPRECATED void *sk_pop(OPENSSL_STACK *sk);
350 
351 // sk_pop_free_ex calls |OPENSSL_sk_pop_free_ex|.
352 //
353 // TODO(b/291994116): Remove this.
354 OPENSSL_EXPORT OPENSSL_DEPRECATED void sk_pop_free_ex(
355     OPENSSL_STACK *sk, OPENSSL_sk_call_free_func call_free_func,
356     OPENSSL_sk_free_func free_func);
357 
358 // sk_pop_free behaves like |OPENSSL_sk_pop_free_ex| but performs an invalid
359 // function pointer cast. It exists because some existing callers called
360 // |sk_pop_free| directly.
361 //
362 // TODO(davidben): Migrate callers to bssl::UniquePtr and remove this.
363 OPENSSL_EXPORT OPENSSL_DEPRECATED void sk_pop_free(
364     OPENSSL_STACK *sk, OPENSSL_sk_free_func free_func);
365 
366 
367 #if !defined(BORINGSSL_NO_CXX)
368 extern "C++" {
369 BSSL_NAMESPACE_BEGIN
370 namespace internal {
371 template <typename T>
372 struct StackTraits {};
373 }
374 BSSL_NAMESPACE_END
375 }
376 
377 #define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const) \
378   extern "C++" {                                            \
379   BSSL_NAMESPACE_BEGIN                                      \
380   namespace internal {                                      \
381   template <>                                               \
382   struct StackTraits<STACK_OF(name)> {                      \
383     static constexpr bool kIsStack = true;                  \
384     using Type = type;                                      \
385     static constexpr bool kIsConst = is_const;              \
386   };                                                        \
387   }                                                         \
388   BSSL_NAMESPACE_END                                        \
389   }
390 
391 #else
392 #define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const)
393 #endif
394 
395 #define BORINGSSL_DEFINE_STACK_OF_IMPL(name, ptrtype, constptrtype)            \
396   /* We disable MSVC C4191 in this macro, which warns when pointers are cast   \
397    * to the wrong type. While the cast itself is valid, it is often a bug      \
398    * because calling it through the cast is UB. However, we never actually     \
399    * call functions as |OPENSSL_sk_cmp_func|. The type is just a type-erased   \
400    * function pointer. (C does not guarantee function pointers fit in          \
401    * |void*|, and GCC will warn on this.) Thus we just disable the false       \
402    * positive warning. */                                                      \
403   OPENSSL_MSVC_PRAGMA(warning(push))                                           \
404   OPENSSL_MSVC_PRAGMA(warning(disable : 4191))                                 \
405   OPENSSL_CLANG_PRAGMA("clang diagnostic push")                                \
406   OPENSSL_CLANG_PRAGMA("clang diagnostic ignored \"-Wunknown-warning-option\"") \
407   OPENSSL_CLANG_PRAGMA("clang diagnostic ignored \"-Wcast-function-type-strict\"") \
408                                                                                \
409   DECLARE_STACK_OF(name)                                                       \
410                                                                                \
411   typedef void (*sk_##name##_free_func)(ptrtype);                              \
412   typedef ptrtype (*sk_##name##_copy_func)(constptrtype);                      \
413   typedef int (*sk_##name##_cmp_func)(constptrtype const *,                    \
414                                       constptrtype const *);                   \
415   typedef int (*sk_##name##_delete_if_func)(ptrtype, void *);                  \
416                                                                                \
417   OPENSSL_INLINE void sk_##name##_call_free_func(                              \
418       OPENSSL_sk_free_func free_func, void *ptr) {                             \
419     ((sk_##name##_free_func)free_func)((ptrtype)ptr);                          \
420   }                                                                            \
421                                                                                \
422   OPENSSL_INLINE void *sk_##name##_call_copy_func(                             \
423       OPENSSL_sk_copy_func copy_func, const void *ptr) {                       \
424     return (void *)((sk_##name##_copy_func)copy_func)((constptrtype)ptr);      \
425   }                                                                            \
426                                                                                \
427   OPENSSL_INLINE int sk_##name##_call_cmp_func(OPENSSL_sk_cmp_func cmp_func,   \
428                                                const void *a, const void *b) { \
429     constptrtype a_ptr = (constptrtype)a;                                      \
430     constptrtype b_ptr = (constptrtype)b;                                      \
431     /* |cmp_func| expects an extra layer of pointers to match qsort. */        \
432     return ((sk_##name##_cmp_func)cmp_func)(&a_ptr, &b_ptr);                   \
433   }                                                                            \
434                                                                                \
435   OPENSSL_INLINE int sk_##name##_call_delete_if_func(                          \
436       OPENSSL_sk_delete_if_func func, void *obj, void *data) {                 \
437     return ((sk_##name##_delete_if_func)func)((ptrtype)obj, data);             \
438   }                                                                            \
439                                                                                \
440   OPENSSL_INLINE STACK_OF(name) *sk_##name##_new(sk_##name##_cmp_func comp) {  \
441     return (STACK_OF(name) *)OPENSSL_sk_new((OPENSSL_sk_cmp_func)comp);        \
442   }                                                                            \
443                                                                                \
444   OPENSSL_INLINE STACK_OF(name) *sk_##name##_new_null(void) {                  \
445     return (STACK_OF(name) *)OPENSSL_sk_new_null();                            \
446   }                                                                            \
447                                                                                \
448   OPENSSL_INLINE size_t sk_##name##_num(const STACK_OF(name) *sk) {            \
449     return OPENSSL_sk_num((const OPENSSL_STACK *)sk);                          \
450   }                                                                            \
451                                                                                \
452   OPENSSL_INLINE void sk_##name##_zero(STACK_OF(name) *sk) {                   \
453     OPENSSL_sk_zero((OPENSSL_STACK *)sk);                                      \
454   }                                                                            \
455                                                                                \
456   OPENSSL_INLINE ptrtype sk_##name##_value(const STACK_OF(name) *sk,           \
457                                            size_t i) {                         \
458     return (ptrtype)OPENSSL_sk_value((const OPENSSL_STACK *)sk, i);            \
459   }                                                                            \
460                                                                                \
461   OPENSSL_INLINE ptrtype sk_##name##_set(STACK_OF(name) *sk, size_t i,         \
462                                          ptrtype p) {                          \
463     return (ptrtype)OPENSSL_sk_set((OPENSSL_STACK *)sk, i, (void *)p);         \
464   }                                                                            \
465                                                                                \
466   OPENSSL_INLINE void sk_##name##_free(STACK_OF(name) *sk) {                   \
467     OPENSSL_sk_free((OPENSSL_STACK *)sk);                                      \
468   }                                                                            \
469                                                                                \
470   OPENSSL_INLINE void sk_##name##_pop_free(STACK_OF(name) *sk,                 \
471                                            sk_##name##_free_func free_func) {  \
472     OPENSSL_sk_pop_free_ex((OPENSSL_STACK *)sk, sk_##name##_call_free_func,    \
473                            (OPENSSL_sk_free_func)free_func);                   \
474   }                                                                            \
475                                                                                \
476   OPENSSL_INLINE size_t sk_##name##_insert(STACK_OF(name) *sk, ptrtype p,      \
477                                            size_t where) {                     \
478     return OPENSSL_sk_insert((OPENSSL_STACK *)sk, (void *)p, where);           \
479   }                                                                            \
480                                                                                \
481   OPENSSL_INLINE ptrtype sk_##name##_delete(STACK_OF(name) *sk,                \
482                                             size_t where) {                    \
483     return (ptrtype)OPENSSL_sk_delete((OPENSSL_STACK *)sk, where);             \
484   }                                                                            \
485                                                                                \
486   OPENSSL_INLINE ptrtype sk_##name##_delete_ptr(STACK_OF(name) *sk,            \
487                                                 constptrtype p) {              \
488     return (ptrtype)OPENSSL_sk_delete_ptr((OPENSSL_STACK *)sk,                 \
489                                           (const void *)p);                    \
490   }                                                                            \
491                                                                                \
492   OPENSSL_INLINE void sk_##name##_delete_if(                                   \
493       STACK_OF(name) *sk, sk_##name##_delete_if_func func, void *data) {       \
494     OPENSSL_sk_delete_if((OPENSSL_STACK *)sk, sk_##name##_call_delete_if_func, \
495                          (OPENSSL_sk_delete_if_func)func, data);               \
496   }                                                                            \
497                                                                                \
498   OPENSSL_INLINE int sk_##name##_find(const STACK_OF(name) *sk,                \
499                                       size_t *out_index, constptrtype p) {     \
500     return OPENSSL_sk_find((const OPENSSL_STACK *)sk, out_index,               \
501                            (const void *)p, sk_##name##_call_cmp_func);        \
502   }                                                                            \
503                                                                                \
504   OPENSSL_INLINE ptrtype sk_##name##_shift(STACK_OF(name) *sk) {               \
505     return (ptrtype)OPENSSL_sk_shift((OPENSSL_STACK *)sk);                     \
506   }                                                                            \
507                                                                                \
508   OPENSSL_INLINE size_t sk_##name##_push(STACK_OF(name) *sk, ptrtype p) {      \
509     return OPENSSL_sk_push((OPENSSL_STACK *)sk, (void *)p);                    \
510   }                                                                            \
511                                                                                \
512   OPENSSL_INLINE ptrtype sk_##name##_pop(STACK_OF(name) *sk) {                 \
513     return (ptrtype)OPENSSL_sk_pop((OPENSSL_STACK *)sk);                       \
514   }                                                                            \
515                                                                                \
516   OPENSSL_INLINE STACK_OF(name) *sk_##name##_dup(const STACK_OF(name) *sk) {   \
517     return (STACK_OF(name) *)OPENSSL_sk_dup((const OPENSSL_STACK *)sk);        \
518   }                                                                            \
519                                                                                \
520   OPENSSL_INLINE void sk_##name##_sort(STACK_OF(name) *sk) {                   \
521     OPENSSL_sk_sort((OPENSSL_STACK *)sk, sk_##name##_call_cmp_func);           \
522   }                                                                            \
523                                                                                \
524   OPENSSL_INLINE int sk_##name##_is_sorted(const STACK_OF(name) *sk) {         \
525     return OPENSSL_sk_is_sorted((const OPENSSL_STACK *)sk);                    \
526   }                                                                            \
527                                                                                \
528   OPENSSL_INLINE sk_##name##_cmp_func sk_##name##_set_cmp_func(                \
529       STACK_OF(name) *sk, sk_##name##_cmp_func comp) {                         \
530     return (sk_##name##_cmp_func)OPENSSL_sk_set_cmp_func(                      \
531         (OPENSSL_STACK *)sk, (OPENSSL_sk_cmp_func)comp);                       \
532   }                                                                            \
533                                                                                \
534   OPENSSL_INLINE STACK_OF(name) *sk_##name##_deep_copy(                        \
535       const STACK_OF(name) *sk, sk_##name##_copy_func copy_func,               \
536       sk_##name##_free_func free_func) {                                       \
537     return (STACK_OF(name) *)OPENSSL_sk_deep_copy(                             \
538         (const OPENSSL_STACK *)sk, sk_##name##_call_copy_func,                 \
539         (OPENSSL_sk_copy_func)copy_func, sk_##name##_call_free_func,           \
540         (OPENSSL_sk_free_func)free_func);                                      \
541   }                                                                            \
542                                                                                \
543   OPENSSL_CLANG_PRAGMA("clang diagnostic pop")                                 \
544   OPENSSL_MSVC_PRAGMA(warning(pop))
545 
546 
547 // Built-in stacks.
548 
549 typedef char *OPENSSL_STRING;
550 
551 DEFINE_STACK_OF(void)
552 DEFINE_NAMED_STACK_OF(OPENSSL_STRING, char)
553 
554 
555 #if defined(__cplusplus)
556 }  // extern C
557 #endif
558 
559 #if !defined(BORINGSSL_NO_CXX)
560 extern "C++" {
561 
562 #include <type_traits>
563 
564 BSSL_NAMESPACE_BEGIN
565 
566 namespace internal {
567 
568 // Stacks defined with |DEFINE_CONST_STACK_OF| are freed with |sk_free|.
569 template <typename Stack>
570 struct DeleterImpl<Stack, std::enable_if_t<StackTraits<Stack>::kIsConst>> {
571   static void Free(Stack *sk) {
572     OPENSSL_sk_free(reinterpret_cast<OPENSSL_STACK *>(sk));
573   }
574 };
575 
576 // Stacks defined with |DEFINE_STACK_OF| are freed with |sk_pop_free| and the
577 // corresponding type's deleter.
578 template <typename Stack>
579 struct DeleterImpl<Stack, std::enable_if_t<!StackTraits<Stack>::kIsConst>> {
580   static void Free(Stack *sk) {
581     // sk_FOO_pop_free is defined by macros and bound by name, so we cannot
582     // access it from C++ here.
583     using Type = typename StackTraits<Stack>::Type;
584     OPENSSL_sk_pop_free_ex(
585         reinterpret_cast<OPENSSL_STACK *>(sk),
586         [](OPENSSL_sk_free_func /* unused */, void *ptr) {
587           DeleterImpl<Type>::Free(reinterpret_cast<Type *>(ptr));
588         },
589         nullptr);
590   }
591 };
592 
593 template <typename Stack>
594 class StackIteratorImpl {
595  public:
596   using Type = typename StackTraits<Stack>::Type;
597   // Iterators must be default-constructable.
598   StackIteratorImpl() : sk_(nullptr), idx_(0) {}
599   StackIteratorImpl(const Stack *sk, size_t idx) : sk_(sk), idx_(idx) {}
600 
601   bool operator==(StackIteratorImpl other) const {
602     return sk_ == other.sk_ && idx_ == other.idx_;
603   }
604   bool operator!=(StackIteratorImpl other) const {
605     return !(*this == other);
606   }
607 
608   Type *operator*() const {
609     return reinterpret_cast<Type *>(
610         OPENSSL_sk_value(reinterpret_cast<const OPENSSL_STACK *>(sk_), idx_));
611   }
612 
613   StackIteratorImpl &operator++(/* prefix */) {
614     idx_++;
615     return *this;
616   }
617 
618   StackIteratorImpl operator++(int /* postfix */) {
619     StackIteratorImpl copy(*this);
620     ++(*this);
621     return copy;
622   }
623 
624  private:
625   const Stack *sk_;
626   size_t idx_;
627 };
628 
629 template <typename Stack>
630 using StackIterator =
631     std::enable_if_t<StackTraits<Stack>::kIsStack, StackIteratorImpl<Stack>>;
632 
633 }  // namespace internal
634 
635 // PushToStack pushes |elem| to |sk|. It returns true on success and false on
636 // allocation failure.
637 template <typename Stack>
638 inline std::enable_if_t<!internal::StackTraits<Stack>::kIsConst, bool>
639 PushToStack(Stack *sk,
640             UniquePtr<typename internal::StackTraits<Stack>::Type> elem) {
641   if (!OPENSSL_sk_push(reinterpret_cast<OPENSSL_STACK *>(sk), elem.get())) {
642     return false;
643   }
644   // OPENSSL_sk_push takes ownership on success.
645   elem.release();
646   return true;
647 }
648 
649 BSSL_NAMESPACE_END
650 
651 // Define begin() and end() for stack types so C++ range for loops work.
652 template <typename Stack>
653 inline bssl::internal::StackIterator<Stack> begin(const Stack *sk) {
654   return bssl::internal::StackIterator<Stack>(sk, 0);
655 }
656 
657 template <typename Stack>
658 inline bssl::internal::StackIterator<Stack> end(const Stack *sk) {
659   return bssl::internal::StackIterator<Stack>(
660       sk, OPENSSL_sk_num(reinterpret_cast<const OPENSSL_STACK *>(sk)));
661 }
662 
663 }  // extern C++
664 #endif
665 
666 #endif  // OPENSSL_HEADER_STACK_H
667