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lxdream.org :: lxdream/src/plugin.c
lxdream 0.9.1
released Jun 29
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filename src/plugin.c
changeset 1296:30ecee61f811
prev1075:1a21750d300c
author nkeynes
date Fri May 29 18:47:05 2015 +1000 (7 years ago)
permissions -rw-r--r--
last change Fix test case
view annotate diff log raw
     1 /**
     2  * $Id$
     3  *
     4  * Plugin loader code
     5  *
     6  * Copyright (c) 2009 Nathan Keynes.
     7  *
     8  * This program is free software; you can redistribute it and/or modify
     9  * it under the terms of the GNU General Public License as published by
    10  * the Free Software Foundation; either version 2 of the License, or
    11  * (at your option) any later version.
    12  *
    13  * This program is distributed in the hope that it will be useful,
    14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    16  * GNU General Public License for more details.
    17  */
    19 #include <sys/stat.h>
    20 #include <dirent.h>
    21 #include <dlfcn.h>
    22 #include <string.h>
    23 #include <glib.h>
    24 #include "plugin.h"
    25 #include "lxpaths.h"
    27 #ifdef APPLE_BUILD
    28 #define SOEXT ".dylib"
    29 #else
    30 #define SOEXT ".so"
    31 #endif
    33 /** Dummy plugin used as a plugin directory marker */
    34 #define DUMMY_PLUGIN ("lxdream_dummy" SOEXT) 
    36 const char *plugin_type_string[] = { "undefined", "audio driver", "input driver" };
    38 int main(int argc, char *argv[]);
    39 static const char *exec_path = NULL;
    41 /**
    42  * Return the full path to the main binary
    43  */
    44 static const char *get_exec_path()
    45 {
    46     if( exec_path == NULL ) {
    47         Dl_info dli;
    49         /* Use dladdr for this, since it should be available for any platform
    50          * that we can support plugins on at all.
    51          */
    52         if( dladdr( main, &dli) ) {
    53             gchar *path = g_strdup( dli.dli_fname );
    54             char *i = strrchr( path, '/' );
    55             if( i > path ) {
    56                 *i = '\0';
    57                 exec_path = path;
    58             } else {
    59                 g_free(path);
    60             }
    61         }
    62     }
    63     return exec_path;
    64 }
    66 static gboolean plugin_load( const gchar *plugin_path )
    67 {
    68     void *so = dlopen(plugin_path, RTLD_NOW|RTLD_LOCAL);
    69     if( so == NULL ) {
    70         WARN("Failed to load plugin '%s': %s", plugin_path, dlerror());
    71         return FALSE;
    72     }
    74     struct plugin_struct *plugin = (struct plugin_struct *)dlsym(so,"lxdream_plugin_entry");
    75     if( plugin == NULL ) {
    76         WARN("Failed to load plugin: '%s': Not an lxdream plugin", plugin_path);
    77         dlclose(so);
    78         return FALSE;
    79     }
    81     if( strcmp(lxdream_short_version, plugin->version) != 0 ) {
    82         WARN("Failed to load plugin: '%s': Incompatible version (%s)", plugin_path, plugin->version);
    83         dlclose(so);
    84         return FALSE;
    85     }
    87     if( plugin->type == PLUGIN_NONE ) {
    88         /* 'dummy' plugin - we don't actually want to load it */
    89         dlclose(so);
    90         return FALSE;
    91     }
    93     if( plugin->type < PLUGIN_MIN_TYPE || plugin->type > PLUGIN_MAX_TYPE ) {
    94         WARN("Failed to load plugin: '%s': Unrecognized plugin type (%d)", plugin_path, plugin->type );
    95         dlclose(so);
    96         return FALSE;
    97     }
    99     if( plugin->register_plugin() == FALSE ) {
   100         WARN("Failed to load plugin: '%s': Initialization failed", plugin_path);
   101         dlclose(so);
   102         return FALSE;
   103     }
   104     DEBUG("Loaded %s '%s'", plugin_type_string[plugin->type], plugin->name);
   105     return TRUE;
   106 }
   108 static gboolean has_plugins( const gchar *path )
   109 {
   110     struct stat st;
   112     gchar *dummy_name = g_strdup_printf( "%s/%s", path, DUMMY_PLUGIN );
   113     if( stat( dummy_name, &st ) == 0 ) {
   114         return TRUE;
   115     } else {
   116         return FALSE;
   117     }
   118 }
   120 /**
   121  * Scan the plugin dir and load all valid plugins.
   122  */
   123 static int plugin_load_all( const gchar *plugin_dir )
   124 {
   125     int plugin_count = 0;
   126     struct dirent *ent;
   128     DIR *dir = opendir(plugin_dir);
   129     if( dir == NULL ) {
   130         WARN( "Unable to open plugin directory '%s'", plugin_dir );
   131         return 0;
   132     }
   134     while( (ent = readdir(dir)) != NULL ) {
   135         const char *ext = strrchr(ent->d_name, '.');
   136         if( ext != NULL && strcasecmp(SOEXT,ext) == 0 ) {
   137             char *libname = g_strdup_printf( "%s/%s", plugin_dir,ent->d_name );
   138             if( plugin_load( libname ) ) {
   139                 plugin_count++;
   140             }
   141             g_free(libname);
   142         }
   143     }
   144     return plugin_count;
   145 }
   147 int plugin_init()
   148 {
   149     const char *path = get_exec_path();
   150     if( path == NULL || !has_plugins(path) ) {
   151         path = get_plugin_path();
   152     }
   154     DEBUG( "Plugin directory: %s", path );
   155     return plugin_load_all( path );
   156 }
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