libbase/sharedlib.cpp

   1 // sharedlib.cpp:  Shared Library support, for Gnash.
   2 //
   3 //   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
   4 //   Free Software Foundation, Inc
   5 //
   6 // This program is free software; you can redistribute it and/or modify
   7 // it under the terms of the GNU General Public License as published by
   8 // the Free Software Foundation; either version 3 of the License, or
   9 // (at your option) any later version.
  10 //
  11 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License
  17 // along with this program; if not, write to the Free Software
  18 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19 //
  20
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include "gnashconfig.h"
  24 #endif
  25
  26 #include "log.h"
  27 #include "sharedlib.h"
  28
  29 #include <sys/stat.h>
  30 #include <unistd.h>
  31
  32 #include <string>
  33 #include <cstdlib>
  34
  35 #if defined(WIN32) || defined(_WIN32)
  36 # define LIBLTDL_DLL_IMPORT 1
  37 #endif
  38 #ifdef HAVE_DLFCN_H
  39 # include <dlfcn.h>
  40 #endif
  41 #ifdef HAVE_LIBGEN_H
  42 # include <libgen.h>
  43 #endif
  44
  45 #include <ltdl.h>
  46 #include <mutex>
  47
  48 #if defined(WIN32) || defined(_WIN32)
  49 int        lt_dlsetsearchpath   (const char *search_path);
  50 int        lt_dlinit           (void);
  51 void *     lt_dlsym            (lt_dlhandle handle, const char *name);
  52 const char *lt_dlerror         (void);
  53 int        lt_dlclose          (lt_dlhandle handle);
  54 int        lt_dlmakeresident   (lt_dlhandle handle);
  55 lt_dlhandle lt_dlopenext       (const char *filename);
  56 #endif
  57
  58 namespace gnash {
  59
  60 SharedLib::SharedLib(const std::string& filespec)
  61 #ifdef HAVE_LTDL
  62   : _dlhandle(nullptr)
  63 #endif
  64 {
  65     _filespec = filespec;
  66     scoped_lock lock(_libMutex);
  67
  68     // Initialize libtool's dynamic library loader
  69 #ifdef HAVE_LTDL
  70     int errors = lt_dlinit ();
  71     if (errors) {
  72         log_error(_("Couldn't initialize ltdl: %s"), lt_dlerror());
  73     }
  74 #else
  75 # warning "libltdl not enabled in build".
  76 #endif
  77 }
  78
  79 bool
  80 SharedLib::closeLib()
  81 {
  82 #ifdef HAVE_LTDL
  83     return lt_dlclose(_dlhandle);
  84 #else
  85     return true;
  86 #endif
  87 }
  88
  89 bool
  90 SharedLib::openLib()
  91 {
  92     return openLib(_filespec);
  93 }
  94
  95 bool
  96 SharedLib::openLib (const std::string& filespec)
  97 {
  98
  99     scoped_lock lock(_libMutex);
 100
 101     log_debug(_("Trying to open shared library \"%s\""), filespec);
 102
 103 #ifdef HAVE_LTDL
 104     _dlhandle = lt_dlopenext (filespec.c_str());
 105
 106     if (_dlhandle == nullptr) {
 107         log_error("lt_dlopenext(\"%s\") failed: %s", filespec.c_str(), lt_dlerror());
 108         return false;
 109     }
 110
 111     // Make this module unloadable
 112     lt_dlmakeresident(_dlhandle);
 113 #endif
 114
 115     log_debug (_("Opened dynamic library \"%s\""), filespec);
 116
 117     _filespec = filespec;
 118
 119     return true;
 120 }
 121
 122 SharedLib::initentry *
 123 SharedLib::getInitEntry (const std::string& symbol)
 124 {
 125     // GNASH_REPORT_FUNCTION;
 126     lt_ptr run = nullptr;
 127
 128     scoped_lock lock(_libMutex);
 129
 130 #ifdef HAVE_LTDL
 131     run  = lt_dlsym (_dlhandle, symbol.c_str());
 132
 133     if (run == nullptr) {
 134         log_error(_("Couldn't find symbol: %s"), symbol);
 135         return nullptr;
 136     } else {
 137         log_debug(_("Found symbol %s @ %p"), symbol, (void *)run);
 138     }
 139 #else
 140     (void)symbol;
 141 #endif
 142
 143     return (initentry*)(run);
 144 }
 145
 146 SharedLib::entrypoint *
 147 SharedLib::getDllSymbol(const std::string& symbol)
 148 {
 149     GNASH_REPORT_FUNCTION;
 150
 151     lt_ptr run = nullptr;
 152
 153     scoped_lock lock(_libMutex);
 154
 155 #ifdef HAVE_LTDL
 156     run  = lt_dlsym (_dlhandle, symbol.c_str());
 157 #endif
 158
 159     /*
 160     Realistically, we should never get a valid pointer with a value of 0
 161     Markus: 'Id est NULL.'
 162     */
 163     if (run == nullptr) {
 164         log_error("Couldn't find symbol: %s", symbol);
 165         return nullptr;
 166     } else {
 167         log_debug("Found symbol %s @ %p", symbol, (void *)run);
 168     }
 169
 170     return (entrypoint*)(run);
 171 }
 172
 173 } // end of gnash namespace