src/security/LockingPointer.h

   1 /*
   2  * Copyright (C) 1996-2016 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #ifndef SQUID_SRC_SECURITY_LOCKINGPOINTER_H
  10 #define SQUID_SRC_SECURITY_LOCKINGPOINTER_H
  11
  12 #include "base/TidyPointer.h"
  13
  14 #if USE_OPENSSL
  15 #if HAVE_OPENSSL_CRYPTO_H
  16 #include <openssl/crypto.h>
  17 #endif
  18
  19 // Macro to be used to define the C++ wrapper function of a sk_*_pop_free
  20 // openssl family functions. The C++ function suffixed with the _free_wrapper
  21 // extension
  22 #define sk_free_wrapper(sk_object, argument, freefunction) \
  23         extern "C++" inline void sk_object ## _free_wrapper(argument a) { \
  24             sk_object ## _pop_free(a, freefunction); \
  25         }
  26
  27 #endif
  28
  29 // Macro to be used to define the C++ equivalent function of an extern "C"
  30 // function. The C++ function suffixed with the _cpp extension
  31 #define CtoCpp1(function, argument) \
  32         extern "C++" inline void function ## _cpp(argument a) { \
  33             function(a); \
  34         }
  35
  36 namespace Security
  37 {
  38
  39 /**
  40  * Add SSL locking (a.k.a. reference counting) and assignment to TidyPointer
  41  */
  42 template <typename T, void (*DeAllocator)(T *t), int lock>
  43 class LockingPointer: public TidyPointer<T, DeAllocator>
  44 {
  45 public:
  46     typedef TidyPointer<T, DeAllocator> Parent;
  47     typedef LockingPointer<T, DeAllocator, lock> SelfType;
  48
  49     explicit LockingPointer(T *t = nullptr): Parent(t) {}
  50
  51     explicit LockingPointer(const SelfType &o): Parent() {
  52         resetAndLock(o.get());
  53     }
  54
  55     SelfType &operator =(const SelfType & o) {
  56         resetAndLock(o.get());
  57         return *this;
  58     }
  59
  60 #if __cplusplus >= 201103L
  61     explicit LockingPointer(LockingPointer<T, DeAllocator, lock> &&o): Parent(o.get()) {
  62         *o.addr() = nullptr;
  63     }
  64
  65     LockingPointer<T, DeAllocator, lock> &operator =(LockingPointer<T, DeAllocator, lock> &&o) {
  66         if (o.get() != this->get()) {
  67             this->reset(o.get());
  68             *o.addr() = nullptr;
  69         }
  70         return *this;
  71     }
  72 #endif
  73
  74     void resetAndLock(T *t) {
  75         if (t != this->get()) {
  76             this->reset(t);
  77 #if USE_OPENSSL
  78             if (t)
  79                 CRYPTO_add(&t->references, 1, lock);
  80 #elif USE_GNUTLS
  81             // XXX: GnuTLS does not provide locking ?
  82 #else
  83             assert(false);
  84 #endif
  85         }
  86     }
  87 };
  88
  89 } // namespace Security
  90
  91 #endif /* SQUID_SRC_SECURITY_LOCKINGPOINTER_H */
  92