wireshark/wsutil/plugins.c

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/* plugins.c
* plugin routines
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include "config.h"
#ifdef HAVE_PLUGINS
#include <time.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <glib.h>
#include <gmodule.h>
#include <wsutil/filesystem.h>
#include <wsutil/privileges.h>
#include <wsutil/file_util.h>
#include <wsutil/report_message.h>
#include <wsutil/plugins.h>
#include <wsutil/ws_printf.h> /* ws_debug_printf */
typedef struct _plugin {
GModule *handle; /* handle returned by g_module_open */
gchar *name; /* plugin name */
const gchar *version; /* plugin version */
const gchar *type_dir; /* filesystem name (where it resides). */
const gchar *type_name; /* user-facing name (what it does). Should these be capitalized? */
} plugin;
#define TYPE_DIR_EPAN "epan"
#define TYPE_DIR_WIRETAP "wiretap"
#define TYPE_DIR_CODECS "codecs"
#define TYPE_NAME_DISSECTOR "dissector"
#define TYPE_NAME_FILE_TYPE "file type"
#define TYPE_NAME_CODEC "codec"
/* array of plugins */
static GPtrArray *plugins_array = NULL;
/* map of names to plugin */
static GHashTable *plugins_table = NULL;
static void
free_plugin(gpointer data)
{
plugin *p = (plugin *)data;
g_module_close(p->handle);
g_free(p->name);
g_free(p);
}
static gint
compare_plugins(gconstpointer a, gconstpointer b)
{
return g_strcmp0((*(const plugin **)a)->name, (*(const plugin **)b)->name);
}
static void
plugins_scan_dir(GPtrArray **plugins_ptr, const char *dirpath, plugin_type_e type, gboolean build_dir)
{
GDir *dir;
const char *name; /* current file name */
gchar *path; /* current file full path */
GModule *handle; /* handle returned by g_module_open */
gpointer symbol;
const char *plug_version, *plug_release;
plugin *new_plug;
gchar *dot;
dir = g_dir_open(dirpath, 0, NULL);
if (dir == NULL)
return;
while ((name = g_dir_read_name(dir)) != NULL) {
/* Skip anything but files with G_MODULE_SUFFIX. */
dot = strrchr(name, '.');
if (dot == NULL || strcmp(dot+1, G_MODULE_SUFFIX) != 0)
continue;
#if WIN32
if (strncmp(name, "nordic_ble.dll", 14) == 0) {
/*
* Skip the Nordic BLE Sniffer dll on WIN32 because
* the dissector has been added as internal.
*/
continue;
}
#endif
/*
* Check if the same name is already registered.
*/
if (g_hash_table_lookup(plugins_table, name)) {
/* Yes, it is. */
if (!build_dir) {
report_warning("The plugin '%s' was found "
"in multiple directories", name);
}
continue;
}
path = g_build_filename(dirpath, name, (gchar *)NULL);
handle = g_module_open(path, G_MODULE_BIND_LOCAL);
g_free(path);
if (handle == NULL) {
/* g_module_error() provides file path. */
report_failure("Couldn't load plugin '%s': %s", name,
g_module_error());
continue;
}
if (!g_module_symbol(handle, "plugin_version", &symbol))
{
report_failure("The plugin '%s' has no \"plugin_version\" symbol", name);
g_module_close(handle);
continue;
}
plug_version = (const char *)symbol;
if (!g_module_symbol(handle, "plugin_release", &symbol))
{
report_failure("The plugin '%s' has no \"plugin_release\" symbol", name);
g_module_close(handle);
continue;
}
plug_release = (const char *)symbol;
if (strcmp(plug_release, VERSION_RELEASE) != 0) {
report_failure("The plugin '%s' was compiled for Wireshark version %s", name, plug_release);
g_module_close(handle);
continue;
}
/* Search for the entry point for the plugin type */
if (!g_module_symbol(handle, "plugin_register", &symbol)) {
report_failure("The plugin '%s' has no \"plugin_register\" symbol", name);
g_module_close(handle);
continue;
}
DIAG_OFF(pedantic)
/* Found it, call the plugin registration function. */
((plugin_register_func)symbol)();
DIAG_ON(pedantic)
new_plug = (plugin *)g_malloc(sizeof(plugin));
new_plug->handle = handle;
new_plug->name = g_strdup(name);
new_plug->version = plug_version;
new_plug->type_dir = "[build]";
switch (type) {
case WS_PLUGIN_EPAN:
if (!build_dir) {
new_plug->type_dir = TYPE_DIR_EPAN;
}
// XXX This isn't true for stats_tree and TRANSUM.
new_plug->type_name = TYPE_NAME_DISSECTOR;
break;
case WS_PLUGIN_WIRETAP:
if (!build_dir) {
new_plug->type_dir = TYPE_DIR_WIRETAP;
}
new_plug->type_name = TYPE_NAME_FILE_TYPE;
break;
case WS_PLUGIN_CODEC:
if (!build_dir) {
new_plug->type_dir = TYPE_DIR_CODECS;
}
new_plug->type_name = TYPE_NAME_CODEC;
break;
default:
g_error("Unknown plugin type: %u. Aborting.", (unsigned) type);
break;
}
/* Add it to the list of plugins. */
if (*plugins_ptr == NULL)
*plugins_ptr = g_ptr_array_new_with_free_func(free_plugin);
g_ptr_array_add(*plugins_ptr, new_plug);
g_ptr_array_add(plugins_array, new_plug);
g_hash_table_insert(plugins_table, new_plug->name, new_plug);
}
ws_dir_close(dir);
}
/*
* Scan the buildir for plugins.
*/
static void
scan_plugins_build_dir(GPtrArray **plugins_ptr, plugin_type_e type)
{
const char *plugin_dir;
const char *name;
char *plugin_dir_path;
WS_DIR *dir; /* scanned directory */
WS_DIRENT *file; /* current file */
plugin_dir = get_plugins_dir();
if ((dir = ws_dir_open(plugin_dir, 0, NULL)) == NULL)
return;
plugins_scan_dir(plugins_ptr, plugin_dir, type, TRUE);
while ((file = ws_dir_read_name(dir)) != NULL)
{
name = ws_dir_get_name(file);
if (strcmp(name, ".") == 0 || strcmp(name, "..") == 0)
continue; /* skip "." and ".." */
/*
* Get the full path of a ".libs" subdirectory of that
* directory.
*/
plugin_dir_path = g_build_filename(plugin_dir, name, ".libs", (gchar *)NULL);
if (test_for_directory(plugin_dir_path) != EISDIR) {
/*
* Either it doesn't refer to a directory or it
* refers to something that doesn't exist.
*
* Assume that means that the plugins are in
* the subdirectory of the plugin directory, not
* a ".libs" subdirectory of that subdirectory.
*/
g_free(plugin_dir_path);
plugin_dir_path = g_build_filename(plugin_dir, name, (gchar *)NULL);
}
plugins_scan_dir(plugins_ptr, plugin_dir_path, type, TRUE);
g_free(plugin_dir_path);
}
ws_dir_close(dir);
}
/*
* Scan for plugins.
*/
plugins_t *
plugins_init(plugin_type_e type)
{
if (!g_module_supported())
return NULL; /* nothing to do */
const char *type_dir;
switch (type) {
case WS_PLUGIN_EPAN:
type_dir = TYPE_DIR_EPAN;
break;
case WS_PLUGIN_WIRETAP:
type_dir = TYPE_DIR_WIRETAP;
break;
case WS_PLUGIN_CODEC:
type_dir = TYPE_DIR_CODECS;
break;
default:
g_error("Unknown plugin type: %u. Aborting.", (unsigned) type);
break;
}
gchar *dirpath;
GPtrArray *plugins = NULL;
if (plugins_table == NULL)
plugins_table = g_hash_table_new(g_str_hash, g_str_equal);
if (plugins_array == NULL)
plugins_array = g_ptr_array_new();
/*
* Scan the global plugin directory.
* If we're running from a build directory, scan the "plugins"
* subdirectory, as that's where plugins are located in an
* out-of-tree build. If we find subdirectories scan those since
* they will contain plugins in the case of an in-tree build.
*/
if (running_in_build_directory())
{
scan_plugins_build_dir(&plugins, type);
}
else
{
dirpath = g_build_filename(get_plugins_dir_with_version(), type_dir, (gchar *)NULL);
plugins_scan_dir(&plugins, dirpath, type, FALSE);
g_free(dirpath);
}
/*
* If the program wasn't started with special privileges,
* scan the users plugin directory. (Even if we relinquish
* them, plugins aren't safe unless we've *permanently*
* relinquished them, and we can't do that in Wireshark as,
* if we need privileges to start capturing, we'd need to
* reclaim them before each time we start capturing.)
*/
if (!started_with_special_privs())
{
dirpath = g_build_filename(get_plugins_pers_dir_with_version(), type_dir, (gchar *)NULL);
plugins_scan_dir(&plugins, dirpath, type, FALSE);
g_free(dirpath);
}
g_ptr_array_sort(plugins_array, compare_plugins);
return plugins;
}
WS_DLL_PUBLIC void
plugins_get_descriptions(plugin_description_callback callback, void *callback_data)
{
if (!plugins_array)
return;
for (guint i = 0; i < plugins_array->len; i++) {
plugin *plug = (plugin *)plugins_array->pdata[i];
callback(plug->name, plug->version, plug->type_name, g_module_name(plug->handle), callback_data);
}
}
static void
print_plugin_description(const char *name, const char *version,
const char *description, const char *filename,
void *user_data _U_)
{
ws_debug_printf("%s\t%s\t%s\t%s\n", name, version, description, filename);
}
void
plugins_dump_all(void)
{
plugins_get_descriptions(print_plugin_description, NULL);
}
int
plugins_get_count(void)
{
if (plugins_table)
return g_hash_table_size(plugins_table);
return 0;
}
void
plugins_cleanup(plugins_t *plugins)
{
if (plugins)
g_ptr_array_free((GPtrArray *)plugins, TRUE);
/*
* This module uses global bookkeeping data structures and per-library
* objects sharing data. To avoid having to walk the plugins GPtrArray
* and delete each plugin from the global data structures we purge them
* once the first plugin cleanup function is called. This means that after
* calling ONE OF POSSIBLY MANY plugin cleanup function NO OTHER plugin
* APIs can be used except plugins_cleanup. If it ever becomes an issue
* it will be easy to change, for a small performance penalty.
*/
if (plugins_table) {
g_hash_table_destroy(plugins_table);
plugins_table = NULL;
}
if (plugins_array) {
g_ptr_array_free(plugins_array, FALSE);
plugins_array = NULL;
}
}
#endif /* HAVE_PLUGINS */
/*
* Editor modelines
*
* Local Variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* ex: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/