src/plugin.c

   1 /*
   2  *
   3  *  neard - Near Field Communication manager
   4  *
   5  *  Copyright (C) 2011  Intel Corporation. All rights reserved.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License version 2 as
   9  *  published by the Free Software Foundation.
  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 <config.h>
  24 #endif
  25
  26 #include <dlfcn.h>
  27
  28 #include <glib.h>
  29
  30 #ifdef NEAR_PLUGIN_BUILTIN
  31 #undef NEAR_PLUGIN_BUILTIN
  32 #endif
  33
  34 #include "near.h"
  35
  36 static GSList *plugins = NULL;
  37
  38 struct near_plugin {
  39         void *handle;
  40         bool active;
  41         struct near_plugin_desc *desc;
  42 };
  43
  44 static gint compare_priority(gconstpointer a, gconstpointer b)
  45 {
  46         const struct near_plugin *plugin1 = a;
  47         const struct near_plugin *plugin2 = b;
  48
  49         return plugin2->desc->priority - plugin1->desc->priority;
  50 }
  51
  52 static bool add_plugin(void *handle, struct near_plugin_desc *desc)
  53 {
  54         struct near_plugin *plugin;
  55
  56         if (!desc->init)
  57                 return false;
  58
  59         if (!g_str_equal(desc->version, NEAR_VERSION)) {
  60                 near_error("Version mismatch for %s", desc->description);
  61                 return false;
  62         }
  63
  64         plugin = g_try_new0(struct near_plugin, 1);
  65         if (!plugin)
  66                 return false;
  67
  68         plugin->handle = handle;
  69         plugin->active = false;
  70         plugin->desc = desc;
  71
  72         plugins = g_slist_insert_sorted(plugins, plugin, compare_priority);
  73
  74         return true;
  75 }
  76
  77 static bool check_plugin(struct near_plugin_desc *desc,
  78                                 char **patterns, char **excludes)
  79 {
  80         if (excludes) {
  81                 for (; *excludes; excludes++)
  82                         if (g_pattern_match_simple(*excludes, desc->name))
  83                                 break;
  84                 if (*excludes) {
  85                         near_info("Excluding %s", desc->description);
  86                         return false;
  87                 }
  88         }
  89
  90         if (patterns) {
  91                 for (; *patterns; patterns++)
  92                         if (g_pattern_match_simple(*patterns, desc->name))
  93                                 break;
  94                 if (!*patterns) {
  95                         near_info("Ignoring %s", desc->description);
  96                         return false;
  97                 }
  98         }
  99
 100         return true;
 101 }
 102
 103 #include "builtin.h"
 104
 105 int __near_plugin_init(const char *pattern, const char *exclude)
 106 {
 107         gchar **patterns = NULL;
 108         gchar **excludes = NULL;
 109         GSList *list;
 110         GDir *dir;
 111         const gchar *file;
 112         gchar *filename;
 113         unsigned int i;
 114
 115         DBG("");
 116
 117         if (pattern)
 118                 patterns = g_strsplit_set(pattern, ":, ", -1);
 119
 120         if (exclude)
 121                 excludes = g_strsplit_set(exclude, ":, ", -1);
 122
 123         for (i = 0; __near_builtin[i]; i++) {
 124                 if (!check_plugin(__near_builtin[i], patterns, excludes))
 125                         continue;
 126
 127                 add_plugin(NULL, __near_builtin[i]);
 128         }
 129
 130         dir = g_dir_open(PLUGINDIR, 0, NULL);
 131         if (dir) {
 132                 while ((file = g_dir_read_name(dir))) {
 133                         void *handle;
 134                         struct near_plugin_desc *desc;
 135
 136                         if (g_str_has_prefix(file, "lib") ||
 137                                         !g_str_has_suffix(file, ".so"))
 138                                 continue;
 139
 140                         filename = g_build_filename(PLUGINDIR, file, NULL);
 141
 142                         handle = dlopen(filename, RTLD_NOW);
 143                         if (!handle) {
 144                                 near_error("Can't load %s: %s",
 145                                                         filename, dlerror());
 146                                 g_free(filename);
 147                                 continue;
 148                         }
 149
 150                         g_free(filename);
 151
 152                         desc = dlsym(handle, "near_plugin_desc");
 153                         if (!desc) {
 154                                 near_error("Can't load symbol: %s",
 155                                                                 dlerror());
 156                                 dlclose(handle);
 157                                 continue;
 158                         }
 159
 160                         if (!check_plugin(desc, patterns, excludes)) {
 161                                 dlclose(handle);
 162                                 continue;
 163                         }
 164
 165                         if (!add_plugin(handle, desc))
 166                                 dlclose(handle);
 167                 }
 168
 169                 g_dir_close(dir);
 170         }
 171
 172         for (list = plugins; list; list = list->next) {
 173                 struct near_plugin *plugin = list->data;
 174
 175                 if (plugin->desc->init() < 0)
 176                         continue;
 177
 178                 plugin->active = true;
 179         }
 180
 181         g_strfreev(patterns);
 182         g_strfreev(excludes);
 183
 184         return 0;
 185 }
 186
 187 void __near_plugin_cleanup(void)
 188 {
 189         GSList *list;
 190
 191         DBG("");
 192
 193         for (list = plugins; list; list = list->next) {
 194                 struct near_plugin *plugin = list->data;
 195
 196                 if (plugin->active && plugin->desc->exit)
 197                         plugin->desc->exit();
 198
 199                 if (plugin->handle)
 200                         dlclose(plugin->handle);
 201
 202                 g_free(plugin);
 203         }
 204
 205         g_slist_free(plugins);
 206 }