Botan::Dynamically_Loaded_Library Class Reference

#include <dyn_load.h>

Public Member Functions
	Dynamically_Loaded_Library (const std::string &lib_name)
template<typename T >
T	resolve (const std::string &symbol)
void *	resolve_symbol (const std::string &symbol)
	~Dynamically_Loaded_Library ()

Detailed Description

Represents a DLL or shared object

Definition at line 19 of file dyn_load.h.

Constructor & Destructor Documentation

Dynamically_Loaded_Library()

Botan::Dynamically_Loaded_Library::Dynamically_Loaded_Library

(

const std::string &

lib_name

)

Load a DLL (or fail with an exception)

Parameters

lib_name

name or path to a library

If you don't use a full path, the search order will be defined by whatever the system linker does by default. Always using fully qualified pathnames can help prevent code injection attacks (eg via manipulation of LD_LIBRARY_PATH on Linux)

Definition at line 35 of file dyn_load.cpp.

                             :
   m_lib_name(library), m_lib(nullptr)
   {
#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
   m_lib = ::dlopen(m_lib_name.c_str(), RTLD_LAZY);

   if(!m_lib)
      raise_runtime_loader_exception(m_lib_name, ::dlerror());

#elif defined(BOTAN_TARGET_OS_HAS_WIN32)
   m_lib = ::LoadLibraryA(m_lib_name.c_str());

   if(!m_lib)
      raise_runtime_loader_exception(m_lib_name, "LoadLibrary failed");
#endif

   if(!m_lib)
      raise_runtime_loader_exception(m_lib_name, "Dynamic load not supported");
   }

~Dynamically_Loaded_Library()

Botan::Dynamically_Loaded_Library::~Dynamically_Loaded_Library

(

)

Unload the DLL

Warning

Any pointers returned by resolve()/resolve_symbol() should not be used after this destructor runs.

Definition at line 56 of file dyn_load.cpp.

   {
#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
   ::dlclose(m_lib);
#elif defined(BOTAN_TARGET_OS_HAS_WIN32)
   ::FreeLibrary((HMODULE)m_lib);
#endif
   }

Member Function Documentation

resolve()

template<typename T >

T Botan::Dynamically_Loaded_Library::resolve ( const std::string &  symbol )

inline

Convenience function for casting symbol to the right type

Parameters

symbol

names the symbol to load

Returns

address of the loaded symbol

Definition at line 53 of file dyn_load.h.

References T.

Referenced by Botan::PKCS11::LowLevel::C_GetFunctionList().

         {
         return reinterpret_cast<T>(resolve_symbol(symbol));
         }

resolve_symbol()

void * Botan::Dynamically_Loaded_Library::resolve_symbol

(

const std::string &

symbol

)

Load a symbol (or fail with an exception)

Parameters

symbol

names the symbol to load

Returns

address of the loaded symbol

Definition at line 65 of file dyn_load.cpp.

   {
   void* addr = nullptr;

#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
   addr = ::dlsym(m_lib, symbol.c_str());
#elif defined(BOTAN_TARGET_OS_HAS_WIN32)
   addr = reinterpret_cast<void*>(::GetProcAddress((HMODULE)m_lib, symbol.c_str()));
#endif

   if(!addr)
      throw Invalid_Argument("Failed to resolve symbol " + symbol +
                             " in " + m_lib_name);

   return addr;
   }

---

The documentation for this class was generated from the following files:

• src/lib/utils/dyn_load/dyn_load.h
• src/lib/utils/dyn_load/dyn_load.cpp