OSX/libsecurity_utilities/lib/seccfobject.h

   1 /*
   2  * Copyright (c) 2000-2004,2011,2013-2014 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24
  25
  26 #ifndef _SECCFOBJECT_H
  27 #define _SECCFOBJECT_H
  28
  29 #include <CoreFoundation/CFRuntime.h>
  30 #include <new>
  31 #include "threading.h"
  32 #include <os/lock.h>
  33
  34 #if( __cplusplus <= 201103L)
  35 #include <stdatomic.h>
  36 #endif
  37
  38 namespace Security {
  39
  40 class CFClass;
  41
  42 #define SECCFFUNCTIONS_BASE(OBJTYPE, APIPTR) \
  43 \
  44 operator APIPTR() const \
  45 { return (APIPTR)(this->operator CFTypeRef()); } \
  46 \
  47 OBJTYPE *retain() \
  48 { SecCFObject::handle(true); return this; } \
  49 APIPTR CF_RETURNS_RETAINED handle() \
  50 { return (APIPTR)SecCFObject::handle(true); } \
  51 APIPTR handle(bool retain) \
  52 { return (APIPTR)SecCFObject::handle(retain); }
  53
  54 #define SECCFFUNCTIONS_CREATABLE(OBJTYPE, APIPTR, CFCLASS) \
  55 SECCFFUNCTIONS_BASE(OBJTYPE, APIPTR)\
  56 \
  57 void *operator new(size_t size)\
  58 { return SecCFObject::allocate(size, CFCLASS); }
  59
  60 #define SECCFFUNCTIONS(OBJTYPE, APIPTR, ERRCODE, CFCLASS) \
  61 SECCFFUNCTIONS_CREATABLE(OBJTYPE, APIPTR, CFCLASS) \
  62 \
  63 static OBJTYPE *required(APIPTR ptr) \
  64 { if (OBJTYPE *p = dynamic_cast<OBJTYPE *>(SecCFObject::required(ptr, ERRCODE))) \
  65         return p; else MacOSError::throwMe(ERRCODE); } \
  66 \
  67 static OBJTYPE *optional(APIPTR ptr) \
  68 { if (SecCFObject *p = SecCFObject::optional(ptr)) \
  69         if (OBJTYPE *pp = dynamic_cast<OBJTYPE *>(p)) return pp; else MacOSError::throwMe(ERRCODE); \
  70   else return NULL; }
  71
  72 #define SECALIGNUP(SIZE, ALIGNMENT) (((SIZE - 1) & ~(ALIGNMENT - 1)) + ALIGNMENT)
  73
  74 struct SecRuntimeBase: CFRuntimeBase
  75 {
  76         atomic_flag isOld;
  77 };
  78
  79 class SecCFObject
  80 {
  81 private:
  82         void *operator new(size_t);
  83
  84         // Align up to a multiple of 16 bytes
  85         static const size_t kAlignedRuntimeSize = SECALIGNUP(sizeof(SecRuntimeBase), 4);
  86
  87     uint32_t mRetainCount;
  88     os_unfair_lock mRetainLock;
  89
  90 public:
  91         // For use by SecPointer only. Returns true once the first time it's called after the object has been created.
  92         bool isNew()
  93         {
  94                 SecRuntimeBase *base = reinterpret_cast<SecRuntimeBase *>(reinterpret_cast<uint8_t *>(this) - kAlignedRuntimeSize);
  95
  96         // atomic flags start clear, and like to go high.
  97         return !atomic_flag_test_and_set(&(base->isOld));
  98         }
  99
 100         static SecCFObject *optional(CFTypeRef) _NOEXCEPT;
 101         static SecCFObject *required(CFTypeRef, OSStatus error);
 102         static void *allocate(size_t size, const CFClass &cfclass);
 103
 104     SecCFObject();
 105         virtual ~SecCFObject();
 106     uint32_t updateRetainCount(intptr_t direction, uint32_t *oldCount);
 107     uint32_t getRetainCount() {return updateRetainCount(0, NULL);}
 108
 109         static void operator delete(void *object) _NOEXCEPT;
 110         virtual operator CFTypeRef() const _NOEXCEPT
 111         {
 112                 return reinterpret_cast<CFTypeRef>(reinterpret_cast<const uint8_t *>(this) - kAlignedRuntimeSize);
 113         }
 114
 115         // This bumps up the retainCount by 1, by calling CFRetain(), iff retain is true
 116         CFTypeRef handle(bool retain = true) _NOEXCEPT;
 117
 118     virtual bool equal(SecCFObject &other);
 119     virtual CFHashCode hash();
 120         virtual CFStringRef copyFormattingDesc(CFDictionaryRef dict);
 121         virtual CFStringRef copyDebugDesc();
 122         virtual void aboutToDestruct();
 123         virtual Mutex* getMutexForObject() const;
 124     virtual bool mayDelete();
 125 };
 126
 127 //
 128 // A pointer type for SecCFObjects.
 129 // T must be derived from SecCFObject.
 130 //
 131 class SecPointerBase
 132 {
 133 public:
 134         SecPointerBase() : ptr(NULL)
 135         {}
 136         SecPointerBase(const SecPointerBase& p);
 137         SecPointerBase(SecCFObject *p);
 138         ~SecPointerBase();
 139         SecPointerBase& operator = (const SecPointerBase& p);
 140
 141 protected:
 142         void assign(SecCFObject * p);
 143         void copy(SecCFObject * p);
 144         SecCFObject *ptr;
 145 };
 146
 147 template <class T>
 148 class SecPointer : public SecPointerBase
 149 {
 150 public:
 151         SecPointer() : SecPointerBase() {}
 152         SecPointer(const SecPointer& p) : SecPointerBase(p) {}
 153         SecPointer(T *p): SecPointerBase(p) {}
 154         SecPointer &operator =(T *p) { this->assign(p); return *this; }
 155         SecPointer &take(T *p) { this->copy(p); return *this; }
 156         T *yield() { T *result = static_cast<T *>(ptr); ptr = NULL; return result; }
 157
 158         // dereference operations
 159     T* get () const                             { return static_cast<T*>(ptr); }        // mimic unique_ptr
 160         operator T * () const           { return static_cast<T*>(ptr); }
 161         T * operator -> () const        { return static_cast<T*>(ptr); }
 162         T & operator * () const         { return *static_cast<T*>(ptr); }
 163
 164     SecPointer& operator=(const SecPointer& other) { SecPointerBase::operator=(other); return *this; }
 165 };
 166
 167 template <class T>
 168 bool operator <(const SecPointer<T> &r1, const SecPointer<T> &r2)
 169 {
 170         T *p1 = r1.get(), *p2 = r2.get();
 171         return p1 && p2 ? *p1 < *p2 : p1 < p2;
 172 }
 173
 174 template <class T>
 175 bool operator ==(const SecPointer<T> &r1, const SecPointer<T> &r2)
 176 {
 177         T *p1 = r1.get(), *p2 = r2.get();
 178         return p1 && p2 ? *p1 == *p2 : p1 == p2;
 179 }
 180
 181 template <class T>
 182 bool operator !=(const SecPointer<T> &r1, const SecPointer<T> &r2)
 183 {
 184         T *p1 = r1.get(), *p2 = r2.get();
 185         return p1 && p2 ? *p1 != *p2 : p1 != p2;
 186 }
 187
 188 } // end namespace Security
 189
 190
 191 #endif