Botan::Dynamically_Loaded_Library Class Reference

#include <dyn_load.h>

Public Member Functions
	Dynamically_Loaded_Library (std::string_view 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

(

std::string_view

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 41 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 61 of file dyn_load.cpp.

                                                        {
#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
   ::dlclose(m_lib);
#elif defined(BOTAN_TARGET_OS_HAS_WIN32)
   ::FreeLibrary(reinterpret_cast<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 52 of file dyn_load.h.

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

References resolve_symbol().

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

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 69 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(reinterpret_cast<HMODULE>(m_lib), symbol.c_str()));
#endif
 
   if(!addr) {
      throw Invalid_Argument(fmt("Failed to resolve symbol {} in {}", symbol, m_lib_name));
   }
 
   return addr;
}

References Botan::fmt().

Referenced by resolve().

---

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