From 05e2e701a8638f5a159392f7ed1fd82b02886fd9 Mon Sep 17 00:00:00 2001 From: Thomas Haller Date: Wed, 18 Jun 2014 11:58:30 +0200 Subject: [PATCH] core: check file permissions when loading device plugins and order by file modification time Refactor the loading of device plugins by creating the list of module filenames in a separate function. Thereby also check for file permissions (must be only modifiable by root) and sort the files by last file modification time. This has the advantage, that if several plugins provide the same device type, that we (deterministically) prefer the most recent one. Signed-off-by: Thomas Haller --- src/nm-manager.c | 112 +++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 93 insertions(+), 19 deletions(-) diff --git a/src/nm-manager.c b/src/nm-manager.c index b806809d80..13b4a01417 100644 --- a/src/nm-manager.c +++ b/src/nm-manager.c @@ -1879,42 +1879,116 @@ factory_component_added_cb (NMDeviceFactory *factory, #define PLUGIN_PATH_TAG "NMManager-plugin-path" #define PLUGIN_TYPEFUNC_TAG "typefunc" -static void -load_device_factories (NMManager *self) +struct read_device_factory_paths_data { + char *path; + struct stat st; +}; + +static gint +read_device_factory_paths_sort_fcn (gconstpointer a, gconstpointer b) +{ + const struct read_device_factory_paths_data *da = a; + const struct read_device_factory_paths_data *db = b; + time_t ta, tb; + + ta = MAX (da->st.st_mtime, da->st.st_ctime); + tb = MAX (db->st.st_mtime, db->st.st_ctime); + + if (ta < tb) + return 1; + if (ta > tb) + return -1; + return 0; +} + +static char** +read_device_factory_paths () { - NMManagerPrivate *priv = NM_MANAGER_GET_PRIVATE (self); GDir *dir; GError *error = NULL; const char *item; - char *path; - GSList *iter; + GArray *paths; + char **result; + guint i; dir = g_dir_open (NMPLUGINDIR, 0, &error); if (!dir) { - nm_log_warn (LOGD_HW, "Failed to open plugin directory %s: %s", + nm_log_warn (LOGD_HW, "device plugin: failed to open directory %s: %s", NMPLUGINDIR, (error && error->message) ? error->message : "(unknown)"); g_clear_error (&error); - return; + return NULL; } + paths = g_array_new (FALSE, FALSE, sizeof (struct read_device_factory_paths_data)); + while ((item = g_dir_read_name (dir))) { - GModule *plugin; - NMDeviceFactory *factory; - NMDeviceFactoryCreateFunc create_func; - NMDeviceFactoryDeviceTypeFunc type_func; - NMDeviceType dev_type; - const char *found = NULL; + struct read_device_factory_paths_data data; if (!g_str_has_prefix (item, PLUGIN_PREFIX)) continue; if (g_str_has_suffix (item, ".la")) continue; - path = g_module_build_path (NMPLUGINDIR, item); - g_assert (path); - plugin = g_module_open (path, G_MODULE_BIND_LOCAL); - g_free (path); + data.path = g_build_filename (NMPLUGINDIR, item, NULL); + + if (stat (data.path, &data.st) != 0) + goto continue_with_error; + if (!S_ISREG (data.st.st_mode)) + goto continue_silently; + if (data.st.st_uid != 0) + goto continue_with_error; + if (data.st.st_mode & (S_IWGRP | S_IWOTH | S_ISUID)) + goto continue_with_error; + + g_array_append_val (paths, data); + continue; + +continue_with_error: + nm_log_dbg (LOGD_HW, "device plugin: skip invalid file %s", data.path); +continue_silently: + g_free (data.path); + } + g_dir_close (dir); + + /* sort filenames by modification time. */ + g_array_sort (paths, read_device_factory_paths_sort_fcn); + + result = g_new (char *, paths->len + 1); + for (i = 0; i < paths->len; i++) + result[i] = g_array_index (paths, struct read_device_factory_paths_data, i).path; + result[i] = NULL; + + g_array_free (paths, TRUE); + return result; +} + +static void +load_device_factories (NMManager *self) +{ + NMManagerPrivate *priv = NM_MANAGER_GET_PRIVATE (self); + char **path; + char **paths; + + paths = read_device_factory_paths (); + if (!paths) + return; + + for (path = paths; *path; path++) { + GError *error = NULL; + GModule *plugin; + NMDeviceFactory *factory; + NMDeviceFactoryCreateFunc create_func; + NMDeviceFactoryDeviceTypeFunc type_func; + NMDeviceType dev_type; + const char *found = NULL; + GSList *iter; + const char *item; + + item = strrchr (*path, '/'); + g_assert (item); + + plugin = g_module_open (*path, G_MODULE_BIND_LOCAL); if (!plugin) { nm_log_warn (LOGD_HW, "(%s): failed to load plugin: %s", item, g_module_error ()); @@ -1939,7 +2013,7 @@ load_device_factories (NMManager *self) } } if (found) { - nm_log_warn (LOGD_HW, "Found multiple device plugins for same type: %s vs %s", + nm_log_warn (LOGD_HW, "Found multiple device plugins for same type: use '%s' instead of '%s'", found, g_module_name (plugin)); g_module_close (plugin); continue; @@ -1978,7 +2052,7 @@ load_device_factories (NMManager *self) nm_log_info (LOGD_HW, "Loaded device plugin: %s", g_module_name (plugin)); }; - g_dir_close (dir); + g_strfreev (paths); priv->factories = g_slist_reverse (priv->factories); }