1 // Copyright 2014 Renato Tegon Forti, Antony Polukhin. 2 // Copyright 2015-2019 Antony Polukhin. 3 // 4 // Distributed under the Boost Software License, Version 1.0. 5 // (See accompanying file LICENSE_1_0.txt 6 // or copy at http://www.boost.org/LICENSE_1_0.txt) 7 8 #ifndef BOOST_DLL_SHARED_LIBRARY_IMPL_HPP 9 #define BOOST_DLL_SHARED_LIBRARY_IMPL_HPP 10 11 #include <boost/dll/config.hpp> 12 #include <boost/dll/shared_library_load_mode.hpp> 13 #include <boost/dll/detail/posix/path_from_handle.hpp> 14 #include <boost/dll/detail/posix/program_location_impl.hpp> 15 16 #include <boost/move/utility.hpp> 17 #include <boost/swap.hpp> 18 #include <boost/predef/os.h> 19 20 #include <dlfcn.h> 21 #include <cstring> // strncmp 22 #if !BOOST_OS_MACOS && !BOOST_OS_IOS && !BOOST_OS_QNX 23 # include <link.h> 24 #elif BOOST_OS_QNX 25 // QNX's copy of <elf.h> and <link.h> reside in sys folder 26 # include <sys/link.h> 27 #endif 28 29 #ifdef BOOST_HAS_PRAGMA_ONCE 30 # pragma once 31 #endif 32 33 namespace boost { namespace dll { namespace detail { 34 35 class shared_library_impl { 36 37 BOOST_MOVABLE_BUT_NOT_COPYABLE(shared_library_impl) 38 39 public: 40 typedef void* native_handle_t; 41 shared_library_impl()42 shared_library_impl() BOOST_NOEXCEPT 43 : handle_(NULL) 44 {} 45 ~shared_library_impl()46 ~shared_library_impl() BOOST_NOEXCEPT { 47 unload(); 48 } 49 shared_library_impl(BOOST_RV_REF (shared_library_impl)sl)50 shared_library_impl(BOOST_RV_REF(shared_library_impl) sl) BOOST_NOEXCEPT 51 : handle_(sl.handle_) 52 { 53 sl.handle_ = NULL; 54 } 55 operator =(BOOST_RV_REF (shared_library_impl)sl)56 shared_library_impl & operator=(BOOST_RV_REF(shared_library_impl) sl) BOOST_NOEXCEPT { 57 swap(sl); 58 return *this; 59 } 60 61 decorate(const boost::dll::fs::path & sl)62 static boost::dll::fs::path decorate(const boost::dll::fs::path & sl) { 63 boost::dll::fs::path actual_path = ( 64 std::strncmp(sl.filename().string().c_str(), "lib", 3) 65 ? boost::dll::fs::path((sl.has_parent_path() ? sl.parent_path() / L"lib" : L"lib").native() + sl.filename().native()) 66 : sl 67 ); 68 actual_path += suffix(); 69 return actual_path; 70 } 71 load(boost::dll::fs::path sl,load_mode::type portable_mode,boost::dll::fs::error_code & ec)72 void load(boost::dll::fs::path sl, load_mode::type portable_mode, boost::dll::fs::error_code &ec) { 73 typedef int native_mode_t; 74 native_mode_t native_mode = static_cast<native_mode_t>(portable_mode); 75 unload(); 76 77 // Do not allow opening NULL paths. User must use program_location() instead 78 if (sl.empty()) { 79 boost::dll::detail::reset_dlerror(); 80 ec = boost::dll::fs::make_error_code( 81 boost::dll::fs::errc::bad_file_descriptor 82 ); 83 84 return; 85 } 86 87 // Fixing modes 88 if (!(native_mode & load_mode::rtld_now)) { 89 native_mode |= load_mode::rtld_lazy; 90 } 91 92 if (!(native_mode & load_mode::rtld_global)) { 93 native_mode |= load_mode::rtld_local; 94 } 95 96 #if BOOST_OS_LINUX || BOOST_OS_ANDROID 97 if (!sl.has_parent_path() && !(native_mode & load_mode::search_system_folders)) { 98 sl = "." / sl; 99 } 100 #else 101 if (!sl.is_absolute() && !(native_mode & load_mode::search_system_folders)) { 102 boost::dll::fs::error_code current_path_ec; 103 boost::dll::fs::path prog_loc = boost::dll::fs::current_path(current_path_ec); 104 if (!current_path_ec) { 105 prog_loc /= sl; 106 sl.swap(prog_loc); 107 } 108 } 109 #endif 110 111 native_mode = static_cast<unsigned>(native_mode) & ~static_cast<unsigned>(load_mode::search_system_folders); 112 113 // Trying to open with appended decorations 114 if (!!(native_mode & load_mode::append_decorations)) { 115 native_mode = static_cast<unsigned>(native_mode) & ~static_cast<unsigned>(load_mode::append_decorations); 116 117 boost::dll::fs::path actual_path = decorate(sl); 118 handle_ = dlopen(actual_path.c_str(), native_mode); 119 if (handle_) { 120 boost::dll::detail::reset_dlerror(); 121 return; 122 } 123 boost::dll::fs::error_code prog_loc_err; 124 boost::dll::fs::path loc = boost::dll::detail::program_location_impl(prog_loc_err); 125 if (boost::dll::fs::exists(actual_path) && !boost::dll::fs::equivalent(sl, loc, prog_loc_err)) { 126 // decorated path exists : current error is not a bad file descriptor and we are not trying to load the executable itself 127 ec = boost::dll::fs::make_error_code( 128 boost::dll::fs::errc::executable_format_error 129 ); 130 return; 131 } 132 } 133 134 // Opening by exactly specified path 135 handle_ = dlopen(sl.c_str(), native_mode); 136 if (handle_) { 137 boost::dll::detail::reset_dlerror(); 138 return; 139 } 140 141 ec = boost::dll::fs::make_error_code( 142 boost::dll::fs::errc::bad_file_descriptor 143 ); 144 145 // Maybe user wanted to load the executable itself? Checking... 146 // We assume that usually user wants to load a dynamic library not the executable itself, that's why 147 // we try this only after traditional load fails. 148 boost::dll::fs::error_code prog_loc_err; 149 boost::dll::fs::path loc = boost::dll::detail::program_location_impl(prog_loc_err); 150 if (!prog_loc_err && boost::dll::fs::equivalent(sl, loc, prog_loc_err) && !prog_loc_err) { 151 // As is known the function dlopen() loads the dynamic library file 152 // named by the null-terminated string filename and returns an opaque 153 // "handle" for the dynamic library. If filename is NULL, then the 154 // returned handle is for the main program. 155 ec.clear(); 156 boost::dll::detail::reset_dlerror(); 157 handle_ = dlopen(NULL, native_mode); 158 if (!handle_) { 159 ec = boost::dll::fs::make_error_code( 160 boost::dll::fs::errc::bad_file_descriptor 161 ); 162 } 163 } 164 } 165 is_loaded() const166 bool is_loaded() const BOOST_NOEXCEPT { 167 return (handle_ != 0); 168 } 169 unload()170 void unload() BOOST_NOEXCEPT { 171 if (!is_loaded()) { 172 return; 173 } 174 175 dlclose(handle_); 176 handle_ = 0; 177 } 178 swap(shared_library_impl & rhs)179 void swap(shared_library_impl& rhs) BOOST_NOEXCEPT { 180 boost::swap(handle_, rhs.handle_); 181 } 182 full_module_path(boost::dll::fs::error_code & ec) const183 boost::dll::fs::path full_module_path(boost::dll::fs::error_code &ec) const { 184 return boost::dll::detail::path_from_handle(handle_, ec); 185 } 186 suffix()187 static boost::dll::fs::path suffix() { 188 // https://sourceforge.net/p/predef/wiki/OperatingSystems/ 189 #if BOOST_OS_MACOS || BOOST_OS_IOS 190 return ".dylib"; 191 #else 192 return ".so"; 193 #endif 194 } 195 symbol_addr(const char * sb,boost::dll::fs::error_code & ec) const196 void* symbol_addr(const char* sb, boost::dll::fs::error_code &ec) const BOOST_NOEXCEPT { 197 // dlsym - obtain the address of a symbol from a dlopen object 198 void* const symbol = dlsym(handle_, sb); 199 if (symbol == NULL) { 200 ec = boost::dll::fs::make_error_code( 201 boost::dll::fs::errc::invalid_seek 202 ); 203 } 204 205 // If handle does not refer to a valid object opened by dlopen(), 206 // or if the named symbol cannot be found within any of the objects 207 // associated with handle, dlsym() shall return NULL. 208 // More detailed diagnostic information shall be available through dlerror(). 209 210 return symbol; 211 } 212 native() const213 native_handle_t native() const BOOST_NOEXCEPT { 214 return handle_; 215 } 216 217 private: 218 native_handle_t handle_; 219 }; 220 221 }}} // boost::dll::detail 222 223 #endif // BOOST_DLL_SHARED_LIBRARY_IMPL_HPP 224