Dogcows Code - chaz/homebank/blob - src/ext-native.c

   1
   2 #include <glib/gstdio.h>
   3 #include <gmodule.h>
   4
   5 #include "ext.h"
   6
   7
   8 static gint ext_native_init(int* argc, char** argv[], char** env[]);
   9 static void ext_native_term(void);
  10 static gboolean ext_native_check_file(const gchar* plugin_filename);
  11 static GHashTable* ext_native_read_plugin_metadata(const gchar* plugin_filepath);
  12 static gint ext_native_load_plugin(const gchar* plugin_filepath);
  13 static void ext_native_unload_plugin(const gchar* plugin_filepath);
  14 static void ext_native_execute_action(const gchar* plugin_filepath);
  15 static void ext_native_call_hook(const gchar* hook_id, GList* args);
  16
  17 static gchar* _read_data_for_keyword(const gchar* keyword, const gchar* bytes, gsize len);
  18
  19
  20 static GHashTable* _loaded_plugins = NULL;
  21
  22
  23 static gint ext_native_init(int* argc, char** argv[], char** env[])
  24 {
  25         if (!_loaded_plugins) {
  26                 _loaded_plugins = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, (GDestroyNotify)g_module_close);
  27         }
  28         return 0;
  29 }
  30
  31 static void ext_native_term(void)
  32 {
  33         if (_loaded_plugins) {
  34                 ext_native_call_hook("unload", NULL);
  35                 g_hash_table_unref(_loaded_plugins);
  36                 _loaded_plugins = NULL;
  37         }
  38 }
  39
  40 static gboolean ext_native_check_file(const gchar* plugin_filename)
  41 {
  42         if (g_str_has_suffix(plugin_filename, "."G_MODULE_SUFFIX)) {
  43                 return TRUE;
  44         }
  45         if (g_str_has_suffix(plugin_filename, ".la")) {
  46                 // allow a .la file only if no actual native plugin is found
  47                 gboolean check = FALSE;
  48                 gchar* copy = g_strdup(plugin_filename);
  49                 gchar* ext  = g_strrstr(copy, ".la");
  50                 if (ext) {
  51                         *ext = '\0';
  52                         gchar* native_filename = g_strconcat(copy, "."G_MODULE_SUFFIX, NULL);
  53                         gchar* native_filepath = ext_find_plugin(native_filename);
  54                         check = !native_filepath;
  55                         g_free(native_filepath);
  56                         g_free(native_filename);
  57                 }
  58                 g_free(copy);
  59                 return check;
  60         }
  61         return FALSE;
  62 }
  63
  64 static GHashTable* ext_native_read_plugin_metadata(const gchar* plugin_filepath)
  65 {
  66         GMappedFile* file = g_mapped_file_new(plugin_filepath, FALSE, NULL);
  67         if (!file) {
  68                 g_printerr("mapping plugin file at %s failed\n", plugin_filepath);
  69                 return NULL;
  70         }
  71
  72         gchar* bytes = g_mapped_file_get_contents(file);
  73         gsize len = g_mapped_file_get_length(file);
  74         if (len == 0 || !bytes) {
  75                 g_mapped_file_unref(file);
  76                 g_printerr("no data in plugin file at %s failed\n", plugin_filepath);
  77                 return NULL;
  78         }
  79
  80         GHashTable* table = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, g_free);
  81
  82         const gchar* keywords[] = { "name", "version", "abstract", "author", "website", NULL };
  83         const gchar** it;
  84         for (it = keywords; *it; ++it) {
  85                 gchar* value = _read_data_for_keyword(*it, bytes, len);
  86                 g_hash_table_insert(table, g_strdup(*it), value);
  87         }
  88
  89         g_mapped_file_unref(file);
  90
  91         return table;
  92 }
  93
  94 static gint ext_native_load_plugin(const gchar* plugin_filepath)
  95 {
  96         if (g_hash_table_contains(_loaded_plugins, plugin_filepath)) {
  97                 return 0;
  98         }
  99
 100         GModule* module = g_module_open(plugin_filepath, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
 101         if (!module) {
 102                 g_printerr("Could not load native plugin: %s\n", g_module_error());
 103                 return -1;
 104         }
 105
 106         g_hash_table_insert(_loaded_plugins, g_strdup(plugin_filepath), module);
 107
 108         void (*symbol)();
 109         if (g_module_symbol(module, "load", (gpointer)&symbol)) {
 110                 symbol();
 111         }
 112
 113         return 0;
 114 }
 115
 116 static void ext_native_unload_plugin(const gchar* plugin_filepath)
 117 {
 118         GModule* module = g_hash_table_lookup(_loaded_plugins, plugin_filepath);
 119         if (module) {
 120                 void (*symbol)();
 121                 if (g_module_symbol(module, "unload", (gpointer)&symbol)) {
 122                         symbol();
 123                 }
 124         }
 125
 126         g_hash_table_remove(_loaded_plugins, plugin_filepath);
 127 }
 128
 129 static void ext_native_execute_action(const gchar* plugin_filepath)
 130 {
 131         GModule* module = g_hash_table_lookup(_loaded_plugins, plugin_filepath);
 132         if (module) {
 133                 void (*symbol)();
 134                 if (g_module_symbol(module, "execute", (gpointer)&symbol)) {
 135                         symbol();
 136                 }
 137         }
 138 }
 139
 140 static void ext_native_call_hook(const gchar* hook_id, GList* args)
 141 {
 142         gchar* symbol_name = g_strconcat("on_", hook_id, NULL);
 143         void (*symbol)(GList*);
 144
 145         GHashTableIter it;
 146         g_hash_table_iter_init(&it, _loaded_plugins);
 147         GModule* module;
 148
 149         while (g_hash_table_iter_next(&it, NULL, (gpointer*)&module)) {
 150                 if (g_module_symbol(module, symbol_name, (gpointer)&symbol)) {
 151                         symbol(args);
 152                 }
 153         }
 154
 155         g_free(symbol_name);
 156 }
 157
 158
 159 static gchar* _read_data_for_keyword(const gchar* keyword, const gchar* bytes, gsize len)
 160 {
 161         gchar* value = NULL;
 162
 163         gchar* pattern = g_strdup_printf("[\\x00\\t\\n ]%s\\s*[=:]\\s*([^\\x00]+)", keyword);
 164         GRegex* r = g_regex_new(pattern, G_REGEX_CASELESS, 0, NULL);
 165         g_free(pattern);
 166
 167         GMatchInfo* match = NULL;
 168         if (g_regex_match_full(r, bytes, len, 0, 0, &match, NULL)) {
 169                 value = g_match_info_fetch(match, 1);
 170         }
 171
 172         g_match_info_free(match);
 173         g_regex_unref(r);
 174
 175         return value;
 176 }
 177
 178
 179 static void _register(void) __attribute__((constructor));
 180 static void _register()
 181 {
 182         ext_register("native",
 183                         ext_native_init,
 184                         ext_native_term,
 185                         ext_native_check_file,
 186                         ext_native_read_plugin_metadata,
 187                         ext_native_load_plugin,
 188                         ext_native_unload_plugin,
 189                         ext_native_execute_action,
 190                         ext_native_call_hook);
 191 }
 192