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 mode,boost::dll::fs::error_code & ec)72 void load(boost::dll::fs::path sl, load_mode::type mode, boost::dll::fs::error_code &ec) { 73 typedef int native_mode_t; 74 unload(); 75 76 // Do not allow opening NULL paths. User must use program_location() instead 77 if (sl.empty()) { 78 boost::dll::detail::reset_dlerror(); 79 ec = boost::dll::fs::make_error_code( 80 boost::dll::fs::errc::bad_file_descriptor 81 ); 82 83 return; 84 } 85 86 // Fixing modes 87 if (!(mode & load_mode::rtld_now)) { 88 mode |= load_mode::rtld_lazy; 89 } 90 91 if (!(mode & load_mode::rtld_global)) { 92 mode |= load_mode::rtld_local; 93 } 94 95 #if BOOST_OS_LINUX || BOOST_OS_ANDROID 96 if (!sl.has_parent_path() && !(mode & load_mode::search_system_folders)) { 97 sl = "." / sl; 98 } 99 #else 100 if (!sl.is_absolute() && !(mode & load_mode::search_system_folders)) { 101 boost::dll::fs::error_code current_path_ec; 102 boost::dll::fs::path prog_loc = boost::dll::fs::current_path(current_path_ec); 103 if (!current_path_ec) { 104 prog_loc /= sl; 105 sl.swap(prog_loc); 106 } 107 } 108 #endif 109 110 mode &= ~load_mode::search_system_folders; 111 112 // Trying to open with appended decorations 113 if (!!(mode & load_mode::append_decorations)) { 114 mode &= ~load_mode::append_decorations; 115 116 boost::dll::fs::path actual_path = decorate(sl); 117 handle_ = dlopen(actual_path.c_str(), static_cast<native_mode_t>(mode)); 118 if (handle_) { 119 boost::dll::detail::reset_dlerror(); 120 return; 121 } 122 boost::dll::fs::error_code prog_loc_err; 123 boost::dll::fs::path loc = boost::dll::detail::program_location_impl(prog_loc_err); 124 if (boost::dll::fs::exists(actual_path) && !boost::dll::fs::equivalent(sl, loc, prog_loc_err)) { 125 // decorated path exists : current error is not a bad file descriptor and we are not trying to load the executable itself 126 ec = boost::dll::fs::make_error_code( 127 boost::dll::fs::errc::executable_format_error 128 ); 129 return; 130 } 131 } 132 133 // Opening by exactly specified path 134 handle_ = dlopen(sl.c_str(), static_cast<native_mode_t>(mode)); 135 if (handle_) { 136 boost::dll::detail::reset_dlerror(); 137 return; 138 } 139 140 ec = boost::dll::fs::make_error_code( 141 boost::dll::fs::errc::bad_file_descriptor 142 ); 143 144 // Maybe user wanted to load the executable itself? Checking... 145 // We assume that usually user wants to load a dynamic library not the executable itself, that's why 146 // we try this only after traditional load fails. 147 boost::dll::fs::error_code prog_loc_err; 148 boost::dll::fs::path loc = boost::dll::detail::program_location_impl(prog_loc_err); 149 if (!prog_loc_err && boost::dll::fs::equivalent(sl, loc, prog_loc_err) && !prog_loc_err) { 150 // As is known the function dlopen() loads the dynamic library file 151 // named by the null-terminated string filename and returns an opaque 152 // "handle" for the dynamic library. If filename is NULL, then the 153 // returned handle is for the main program. 154 ec.clear(); 155 boost::dll::detail::reset_dlerror(); 156 handle_ = dlopen(NULL, static_cast<native_mode_t>(mode)); 157 if (!handle_) { 158 ec = boost::dll::fs::make_error_code( 159 boost::dll::fs::errc::bad_file_descriptor 160 ); 161 } 162 } 163 } 164 is_loaded() const165 bool is_loaded() const BOOST_NOEXCEPT { 166 return (handle_ != 0); 167 } 168 unload()169 void unload() BOOST_NOEXCEPT { 170 if (!is_loaded()) { 171 return; 172 } 173 174 dlclose(handle_); 175 handle_ = 0; 176 } 177 swap(shared_library_impl & rhs)178 void swap(shared_library_impl& rhs) BOOST_NOEXCEPT { 179 boost::swap(handle_, rhs.handle_); 180 } 181 full_module_path(boost::dll::fs::error_code & ec) const182 boost::dll::fs::path full_module_path(boost::dll::fs::error_code &ec) const { 183 return boost::dll::detail::path_from_handle(handle_, ec); 184 } 185 suffix()186 static boost::dll::fs::path suffix() { 187 // https://sourceforge.net/p/predef/wiki/OperatingSystems/ 188 #if BOOST_OS_MACOS || BOOST_OS_IOS 189 return ".dylib"; 190 #else 191 return ".so"; 192 #endif 193 } 194 symbol_addr(const char * sb,boost::dll::fs::error_code & ec) const195 void* symbol_addr(const char* sb, boost::dll::fs::error_code &ec) const BOOST_NOEXCEPT { 196 // dlsym - obtain the address of a symbol from a dlopen object 197 void* const symbol = dlsym(handle_, sb); 198 if (symbol == NULL) { 199 ec = boost::dll::fs::make_error_code( 200 boost::dll::fs::errc::invalid_seek 201 ); 202 } 203 204 // If handle does not refer to a valid object opened by dlopen(), 205 // or if the named symbol cannot be found within any of the objects 206 // associated with handle, dlsym() shall return NULL. 207 // More detailed diagnostic information shall be available through dlerror(). 208 209 return symbol; 210 } 211 native() const212 native_handle_t native() const BOOST_NOEXCEPT { 213 return handle_; 214 } 215 216 private: 217 native_handle_t handle_; 218 }; 219 220 }}} // boost::dll::detail 221 222 #endif // BOOST_DLL_SHARED_LIBRARY_IMPL_HPP 223