Adding upstream version 4.2.2.upstream/4.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2225 insertions, 0 deletions

diff --git a/extcap.c b/extcap.c
new file mode 100644
index 00000000..63612a2f
--- /dev/null
+++ b/extcap.c
@@ -0,0 +1,2225 @@
+/* extcap.c
+ *
+ * Routines for extcap external capture
+ * Copyright 2013, Mike Ryan <mikeryan@lacklustre.net>
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include <config.h>
+#define WS_LOG_DOMAIN LOG_DOMAIN_EXTCAP
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef _WIN32
+#include <windows.h>
+#include <process.h>
+#include <time.h>
+#else
+/* Include for unlink */
+#include <unistd.h>
+#endif
+
+#include <sys/types.h>
+
+#include <glib.h>
+
+#include <epan/prefs.h>
+
+#include "ui/iface_toolbar.h"
+
+#include <wsutil/file_util.h>
+#include <wsutil/filesystem.h>
+#include <wsutil/ws_pipe.h>
+#include <wsutil/tempfile.h>
+#include <wsutil/wslog.h>
+#include <wsutil/ws_assert.h>
+#include <wsutil/version_info.h>
+
+#include "capture/capture_session.h"
+#include "capture_opts.h"
+
+#include "extcap.h"
+#include "extcap_parser.h"
+
+/* Number of seconds to wait for extcap process to exit after cleanup.
+ * If extcap does not exit before the timeout, it is forcefully terminated.
+ */
+#ifdef _WIN32
+/* Extcap interface does not specify SIGTERM replacement on Windows yet */
+#define EXTCAP_CLEANUP_TIMEOUT 0
+#else
+#define EXTCAP_CLEANUP_TIMEOUT 30
+#endif
+
+/* internal container, for all the extcap executables that have been found.
+ * Will be reset if extcap_clear_interfaces() is being explicitly called
+ * and is being used for printing information about all extcap interfaces found,
+ * as well as storing all sub-interfaces
+ */
+static GHashTable * _loaded_interfaces = NULL;
+
+/* Internal container, which maps each ifname to the tool providing it, for faster
+ * lookup. The key and string value are owned by this table.
+ */
+static GHashTable * _tool_for_ifname = NULL;
+
+/* internal container, for all the extcap executables that have been found
+ * and that provides a toolbar with controls to be added to a Interface Toolbar
+ */
+static GHashTable *_toolbars = NULL;
+
+/* internal container, to map preference names to pointers that hold preference
+ * values. These ensure that preferences can survive extcap if garbage
+ * collection, and does not lead to dangling pointers in the prefs subsystem.
+ */
+static GHashTable *_extcap_prefs_dynamic_vals = NULL;
+
+typedef struct _extcap_callback_info_t
+{
+    const gchar * extcap;
+    const gchar * ifname;
+    gchar * output;
+    void * data;
+    gchar ** err_str;
+} extcap_callback_info_t;
+
+/* Callback definition for extcap_foreach */
+typedef gboolean(*extcap_cb_t)(extcap_callback_info_t info_structure);
+
+/** GThreadPool does not support pushing new work from a thread while waiting
+ * for the thread pool to finish. This data structure tracks ongoing work.
+ * See https://gitlab.gnome.org/GNOME/glib/issues/1598 */
+typedef struct thread_pool {
+    GThreadPool    *pool;
+    gint            count;  /**< Number of tasks that have not finished. */
+    GCond           cond;
+    GMutex          data_mutex;
+} thread_pool_t;
+
+/**
+ * Callback definition for extcap_run_all, invoked with a thread pool (to
+ * schedule new tasks), an opaque data parameter, and the output from last task
+ * (or NULL if it failed). The output must be freed by the callback function.
+ * The implementation MUST be thread-safe.
+ */
+typedef void (*extcap_run_cb_t)(thread_pool_t *pool, void *data, char *output);
+
+typedef struct extcap_run_task {
+    const char     *extcap_path;
+    char          **argv;       /**< NULL-terminated arguments list, freed when the task is completed. */
+    extcap_run_cb_t output_cb;
+    void           *data;       /** Parameter to be passed to output_cb. */
+} extcap_run_task_t;
+
+typedef struct extcap_iface_info {
+    char *ifname;                       /**< Interface name. */
+    char *output;                       /**< Output of --extcap-config. */
+} extcap_iface_info_t;
+
+typedef struct extcap_run_extcaps_info {
+    char    *extcap_path;               /**< Extcap program path, MUST be the first member.  */
+    char    *output;                    /**< Output of --extcap-interfaces. */
+    guint   num_interfaces;             /**< Number of discovered interfaces. */
+    extcap_iface_info_t *iface_infos;   /**< Per-interface information. */
+} extcap_run_extcaps_info_t;
+
+
+static void extcap_load_interface_list(void);
+
+/* Used for lazily loading our interfaces. */
+static void extcap_ensure_all_interfaces_loaded(void) {
+    if ( !_loaded_interfaces || g_hash_table_size(_loaded_interfaces) == 0 )
+        extcap_load_interface_list();
+}
+
+static gboolean
+thread_pool_push(thread_pool_t *pool, gpointer data, GError **error)
+{
+    g_mutex_lock(&pool->data_mutex);
+    ++pool->count;
+    g_mutex_unlock(&pool->data_mutex);
+    return g_thread_pool_push(pool->pool, data, error);
+}
+
+static void
+thread_pool_wait(thread_pool_t *pool)
+{
+    g_mutex_lock(&pool->data_mutex);
+    while (pool->count != 0) {
+        g_cond_wait(&pool->cond, &pool->data_mutex);
+    }
+    g_mutex_unlock(&pool->data_mutex);
+}
+
+static GHashTable *
+extcap_loaded_interfaces(void)
+{
+    if (prefs.capture_no_extcap)
+        return NULL;
+
+    extcap_ensure_all_interfaces_loaded();
+
+    return _loaded_interfaces;
+}
+
+void
+extcap_clear_interfaces(void)
+{
+    if ( _loaded_interfaces )
+        g_hash_table_destroy(_loaded_interfaces);
+    _loaded_interfaces = NULL;
+
+    if ( _tool_for_ifname )
+        g_hash_table_destroy(_tool_for_ifname);
+    _tool_for_ifname = NULL;
+}
+
+static gint
+compare_tools(gconstpointer a, gconstpointer b)
+{
+    return g_strcmp0((*(extcap_info *const *)a)->basename, (*(extcap_info *const *)b)->basename);
+}
+
+void
+extcap_get_descriptions(plugin_description_callback callback, void *callback_data)
+{
+    extcap_ensure_all_interfaces_loaded();
+
+    GHashTable * tools = extcap_loaded_interfaces();
+    GPtrArray *tools_array = g_ptr_array_new();
+
+    if (tools && g_hash_table_size(tools) > 0) {
+        GList * keys = g_hash_table_get_keys(tools);
+        GList * walker = g_list_first(keys);
+        while (walker && walker->data) {
+            extcap_info * tool = (extcap_info *)g_hash_table_lookup(tools, walker->data);
+            if (tool) {
+                g_ptr_array_add(tools_array, tool);
+            }
+            walker = g_list_next(walker);
+        }
+        g_list_free(keys);
+    }
+
+    g_ptr_array_sort(tools_array, compare_tools);
+
+    for (guint i = 0; i < tools_array->len; i++) {
+        extcap_info *tool = (extcap_info *)tools_array->pdata[i];
+        callback(tool->basename, tool->version, "extcap", tool->full_path, callback_data);
+    }
+
+    g_ptr_array_free(tools_array, TRUE);
+}
+
+static void
+print_extcap_description(const char *basename, const char *version,
+                        const char *description, const char *filename,
+                        void *user_data _U_)
+{
+    printf("%-16s\t%s\t%s\t%s\n", basename, version, description, filename);
+}
+
+void
+extcap_dump_all(void)
+{
+    extcap_get_descriptions(print_extcap_description, NULL);
+}
+
+static GSList *
+extcap_get_extcap_paths_from_dir(GSList * list, const char * dirname)
+{
+    GDir * dir;
+    const char * file;
+
+    GSList * paths = list;
+
+    if ((dir = g_dir_open(dirname, 0, NULL)) != NULL) {
+        while ((file = g_dir_read_name(dir)) != NULL) {
+            /* full path to extcap binary */
+            gchar *extcap_path = ws_strdup_printf("%s" G_DIR_SEPARATOR_S "%s", dirname, file);
+            /* treat anything executable as an extcap binary */
+            if (g_file_test(extcap_path, G_FILE_TEST_IS_REGULAR) &&
+                g_file_test(extcap_path, G_FILE_TEST_IS_EXECUTABLE)) {
+                paths = g_slist_append(paths, extcap_path);
+            } else {
+                g_free(extcap_path);
+            }
+
+        }
+        g_dir_close(dir);
+    }
+
+    return paths;
+}
+
+/**
+ * Obtains a list of extcap program paths. Use g_slist_free_full(paths, g_free)
+ * to destroy the list.
+ */
+static GSList *
+extcap_get_extcap_paths(void)
+{
+    GSList *paths = NULL;
+
+    paths = extcap_get_extcap_paths_from_dir(paths, get_extcap_pers_dir());
+    paths = extcap_get_extcap_paths_from_dir(paths, get_extcap_dir());
+
+    return paths;
+}
+
+static extcap_interface *
+extcap_find_interface_for_ifname(const gchar *ifname)
+{
+    extcap_interface * result = NULL;
+
+    if ( !ifname || ! _tool_for_ifname || ! _loaded_interfaces )
+        return result;
+
+    gchar * extcap_util = (gchar *)g_hash_table_lookup(_tool_for_ifname, ifname);
+    if ( ! extcap_util )
+        return result;
+
+    extcap_info * element = (extcap_info *)g_hash_table_lookup(_loaded_interfaces, extcap_util);
+    if ( ! element )
+        return result;
+
+    GList * walker = element->interfaces;
+    while ( walker && walker->data && ! result )
+    {
+        extcap_interface * interface = (extcap_interface *)walker->data;
+        if ( g_strcmp0(interface->call, ifname) == 0 )
+        {
+            result = interface;
+            break;
+        }
+
+        walker = g_list_next ( walker );
+    }
+
+    return result;
+}
+
+static void
+extcap_free_toolbar(gpointer data)
+{
+    if (!data)
+    {
+        return;
+    }
+
+    iface_toolbar *toolbar = (iface_toolbar *)data;
+
+    g_free(toolbar->menu_title);
+    g_free(toolbar->help);
+    g_list_free_full(toolbar->ifnames, g_free);
+    g_list_free_full(toolbar->controls, (GDestroyNotify)extcap_free_toolbar_control);
+    g_free(toolbar);
+}
+
+static gchar *
+extcap_if_executable(const gchar *ifname)
+{
+    extcap_interface *interface = extcap_find_interface_for_ifname(ifname);
+    return interface != NULL ? interface->extcap_path : NULL;
+}
+
+static gboolean
+extcap_iface_toolbar_add(const gchar *extcap, iface_toolbar *toolbar_entry)
+{
+    char *toolname;
+    gboolean ret = FALSE;
+
+    if (!extcap || !toolbar_entry)
+    {
+        return ret;
+    }
+
+    toolname = g_path_get_basename(extcap);
+
+    if (!g_hash_table_lookup(_toolbars, toolname))
+    {
+        g_hash_table_insert(_toolbars, g_strdup(toolname), toolbar_entry);
+        ret = TRUE;
+    }
+
+    g_free(toolname);
+    return ret;
+}
+
+static gchar **
+extcap_convert_arguments_to_array(GList * arguments)
+{
+    gchar ** result = NULL;
+    if ( arguments )
+    {
+        GList * walker = g_list_first(arguments);
+        int cnt = 0;
+
+        result = (gchar **) g_malloc0(sizeof(gchar *) * (g_list_length(arguments)));
+
+        while(walker)
+        {
+            result[cnt] = g_strdup((const gchar *)walker->data);
+            walker = g_list_next(walker);
+            cnt++;
+        }
+    }
+    return result;
+}
+
+static void extcap_free_array(gchar ** args, int argc)
+{
+    int cnt = 0;
+
+    for ( cnt = 0; cnt < argc; cnt++ )
+        g_free(args[cnt]);
+    g_free(args);
+}
+
+static void
+extcap_free_extcaps_info_array(extcap_run_extcaps_info_t *infos, guint count)
+{
+    for (guint i = 0; i < count; i++) {
+        g_free(infos[i].extcap_path);
+        g_free(infos[i].output);
+        for (guint j = 0; j < infos[i].num_interfaces; j++) {
+            extcap_iface_info_t *iface_info = &infos[i].iface_infos[j];
+            g_free(iface_info->ifname);
+            g_free(iface_info->output);
+        }
+        g_free(infos[i].iface_infos);
+    }
+    g_free(infos);
+}
+
+static void
+extcap_run_one(const extcap_interface *interface, GList *arguments, extcap_cb_t cb, void *user_data, char **err_str)
+{
+    const char *dirname = get_extcap_dir();
+    gchar **args = extcap_convert_arguments_to_array(arguments);
+    int cnt = g_list_length(arguments);
+    gchar *command_output;
+    if (ws_pipe_spawn_sync(dirname, interface->extcap_path, cnt, args, &command_output)) {
+        extcap_callback_info_t cb_info = {
+            .ifname = interface->call,
+            .extcap = interface->extcap_path,
+            .output = command_output,
+            .data = user_data,
+            .err_str = err_str,
+        };
+        cb(cb_info);
+        g_free(command_output);
+    }
+    extcap_free_array(args, cnt);
+}
+
+/** Thread callback to run an extcap program and pass its output. */
+static void
+extcap_thread_callback(gpointer data, gpointer user_data)
+{
+    extcap_run_task_t *task = (extcap_run_task_t *)data;
+    thread_pool_t *pool = (thread_pool_t *)user_data;
+    const char *dirname = get_extcap_dir();
+
+    char *command_output;
+    if (ws_pipe_spawn_sync(dirname, task->extcap_path, g_strv_length(task->argv), task->argv, &command_output)) {
+        task->output_cb(pool, task->data, command_output);
+    } else {
+        task->output_cb(pool, task->data, NULL);
+    }
+    g_strfreev(task->argv);
+    g_free(task);
+
+    // Notify when all tasks are completed and no new subtasks were created.
+    g_mutex_lock(&pool->data_mutex);
+    if (--pool->count == 0) {
+        g_cond_signal(&pool->cond);
+    }
+    g_mutex_unlock(&pool->data_mutex);
+}
+
+/*
+ * Run all extcap programs with the given arguments list, invoke the callback to
+ * do some processing and return the results.
+ *
+ * @param [IN] argv NULL-terminated arguments list.
+ * @param [IN] output_cb Thread callback function that receives the output.
+ * @param [IN] data_size Size of the per-program information that will be returned.
+ * @param [OUT] count Size of the returned array.
+ * @return Array of information or NULL if there are none. The first member of
+ * each element (char *extcap_path) must be freed.
+ */
+static gpointer
+extcap_run_all(const char *argv[], extcap_run_cb_t output_cb, gsize data_size, guint *count)
+{
+    /* Need enough space for at least 'extcap_path'. */
+    ws_assert(data_size >= sizeof(char *));
+
+    GSList *paths = extcap_get_extcap_paths();
+    int i = 0;
+    int max_threads = (int)g_get_num_processors();
+
+    if (!paths) {
+        *count = 0;
+        return NULL;
+    }
+
+    guint64 start_time = g_get_monotonic_time();
+    guint paths_count = g_slist_length(paths);
+    /* GSList is not thread-safe, so pre-allocate an array instead. */
+    gpointer infos = g_malloc0_n(paths_count, data_size);
+
+    thread_pool_t pool;
+    pool.pool = g_thread_pool_new(extcap_thread_callback, &pool, max_threads, FALSE, NULL);
+    pool.count = 0;
+    g_cond_init(&pool.cond);
+    g_mutex_init(&pool.data_mutex);
+
+    for (GSList *path = paths; path; path = g_slist_next(path), i++) {
+        extcap_run_task_t *task = g_new0(extcap_run_task_t, 1);
+
+        task->extcap_path = (char *)path->data;
+        task->argv = g_strdupv((char **)argv);
+        task->output_cb = output_cb;
+        task->data = ((char *)infos) + (i * data_size);
+        *((char **)task->data) = (char *)path->data;
+
+        thread_pool_push(&pool, task, NULL);
+    }
+    g_slist_free(paths);    /* Note: the contents are transferred to 'infos'. */
+
+    /* Wait for all (sub)tasks to complete. */
+    thread_pool_wait(&pool);
+
+    g_mutex_clear(&pool.data_mutex);
+    g_cond_clear(&pool.cond);
+    g_thread_pool_free(pool.pool, FALSE, TRUE);
+
+    ws_debug("extcap: completed discovery of %d tools in %.3fms",
+            paths_count, (g_get_monotonic_time() - start_time) / 1000.0);
+    *count = paths_count;
+    return infos;
+}
+
+static void extcap_free_dlt(gpointer d, gpointer user_data _U_)
+{
+    if (d == NULL)
+    {
+        return;
+    }
+
+    g_free(((extcap_dlt *)d)->name);
+    g_free(((extcap_dlt *)d)->display);
+    g_free(d);
+}
+
+static void extcap_free_dlts(GList *dlts)
+{
+    g_list_foreach(dlts, extcap_free_dlt, NULL);
+    g_list_free(dlts);
+}
+
+static gboolean cb_dlt(extcap_callback_info_t cb_info)
+{
+    GList *dlts = NULL, *temp = NULL;
+
+    if_capabilities_t *caps;
+    GList *linktype_list = NULL;
+    data_link_info_t *data_link_info;
+    extcap_dlt *dlt_item;
+
+    dlts = extcap_parse_dlts(cb_info.output);
+    temp = dlts;
+
+    ws_debug("Extcap pipe %s ", cb_info.extcap);
+
+    /*
+     * Allocate the interface capabilities structure.
+     */
+    caps = (if_capabilities_t *) g_malloc(sizeof * caps);
+    caps->can_set_rfmon = FALSE;
+    caps->timestamp_types = NULL;
+
+    while (dlts)
+    {
+        dlt_item = (extcap_dlt *)dlts->data;
+        if (dlt_item)
+        {
+            ws_debug("  DLT %d name=\"%s\" display=\"%s\" ", dlt_item->number,
+                  dlt_item->name, dlt_item->display);
+
+            data_link_info = g_new(data_link_info_t, 1);
+            data_link_info->dlt = dlt_item->number;
+            data_link_info->name = g_strdup(dlt_item->name);
+            data_link_info->description = g_strdup(dlt_item->display);
+            linktype_list = g_list_append(linktype_list, data_link_info);
+        }
+
+        dlts = g_list_next(dlts);
+    }
+
+    /* Check to see if we built a list */
+    if (linktype_list != NULL && cb_info.data != NULL)
+    {
+        caps->data_link_types = linktype_list;
+        *(if_capabilities_t **) cb_info.data = caps;
+    }
+    else
+    {
+        if (cb_info.err_str)
+        {
+            ws_debug("  returned no DLTs");
+            *(cb_info.err_str) = g_strdup("Extcap returned no DLTs");
+        }
+        g_free(caps);
+    }
+
+    extcap_free_dlts(temp);
+
+    return FALSE;
+}
+
+if_capabilities_t *
+extcap_get_if_dlts(const gchar *ifname, char **err_str)
+{
+    GList * arguments = NULL;
+    if_capabilities_t *caps = NULL;
+
+    if (err_str != NULL)
+    {
+        *err_str = NULL;
+    }
+
+    /* Update the extcap interfaces and get a list of their if_infos */
+    extcap_ensure_all_interfaces_loaded();
+
+    extcap_interface *interface = extcap_find_interface_for_ifname(ifname);
+    if (interface)
+    {
+        arguments = g_list_append(arguments, g_strdup(EXTCAP_ARGUMENT_LIST_DLTS));
+        arguments = g_list_append(arguments, g_strdup(EXTCAP_ARGUMENT_INTERFACE));
+        arguments = g_list_append(arguments, g_strdup(ifname));
+
+        extcap_run_one(interface, arguments, cb_dlt, &caps, err_str);
+
+        g_list_free_full(arguments, g_free);
+    }
+
+    return caps;
+}
+
+static void extcap_free_interface(gpointer i)
+{
+
+    extcap_interface *interface = (extcap_interface *)i;
+
+    if (i == NULL)
+    {
+        return;
+    }
+
+    g_free(interface->call);
+    g_free(interface->display);
+    g_free(interface->version);
+    g_free(interface->help);
+    g_free(interface->extcap_path);
+    g_free(interface);
+}
+
+static void extcap_free_interfaces(GList *interfaces)
+{
+    if (interfaces == NULL)
+    {
+        return;
+    }
+
+    g_list_free_full(interfaces, extcap_free_interface);
+}
+
+static gint
+if_info_compare(gconstpointer a, gconstpointer b)
+{
+    gint comp = 0;
+    const if_info_t *if_a = (const if_info_t *)a;
+    const if_info_t *if_b = (const if_info_t *)b;
+
+    if ((comp = g_strcmp0(if_a->name, if_b->name)) == 0)
+    {
+        return g_strcmp0(if_a->friendly_name, if_b->friendly_name);
+    }
+
+    return comp;
+}
+
+gchar *
+extcap_get_help_for_ifname(const char *ifname)
+{
+    extcap_ensure_all_interfaces_loaded();
+
+    extcap_interface *interface = extcap_find_interface_for_ifname(ifname);
+    return interface != NULL ? interface->help : NULL;
+}
+
+GList *
+append_extcap_interface_list(GList *list)
+{
+    GList *interface_list = NULL;
+    extcap_interface *data = NULL;
+    GList *ifutilkeys_head = NULL, *ifutilkeys = NULL;
+
+    if (prefs.capture_no_extcap)
+        return list;
+
+    /* Update the extcap interfaces and get a list of their if_infos */
+    extcap_ensure_all_interfaces_loaded();
+
+    ifutilkeys_head = g_hash_table_get_keys(_loaded_interfaces);
+    ifutilkeys = ifutilkeys_head;
+    while ( ifutilkeys && ifutilkeys->data )
+    {
+        extcap_info * extinfo =
+                (extcap_info *) g_hash_table_lookup(_loaded_interfaces, (gchar *)ifutilkeys->data);
+        GList * walker = extinfo->interfaces;
+        while ( walker && walker->data )
+        {
+            interface_list = g_list_append(interface_list, walker->data);
+            walker = g_list_next(walker);
+        }
+
+        ifutilkeys = g_list_next(ifutilkeys);
+    }
+    g_list_free(ifutilkeys_head);
+
+    /* Sort that list */
+    interface_list = g_list_sort(interface_list, if_info_compare);
+
+    /* Append the interfaces in that list to the list we're handed. */
+    while (interface_list != NULL)
+    {
+        GList *entry = g_list_first(interface_list);
+        data = (extcap_interface *)entry->data;
+        interface_list = g_list_delete_link(interface_list, entry);
+
+        if_info_t * if_info = g_new0(if_info_t, 1);
+        if_info->name = g_strdup(data->call);
+        if_info->friendly_name = g_strdup(data->display);
+
+        if_info->type = IF_EXTCAP;
+
+        if_info->extcap = g_strdup(data->extcap_path);
+
+        list = g_list_append(list, if_info);
+    }
+
+    return list;
+}
+
+void extcap_register_preferences(void)
+{
+    if (prefs.capture_no_extcap)
+        return;
+
+    module_t *dev_module = prefs_find_module("extcap");
+
+    if (!dev_module)
+    {
+        return;
+    }
+
+    // Will load information about extcaps and their supported config.
+    extcap_ensure_all_interfaces_loaded();
+}
+
+/**
+ * Releases the dynamic preference value pointers. Must not be called before
+ * prefs_cleanup since these pointers could still be in use.
+ */
+void extcap_cleanup(void)
+{
+    if (_extcap_prefs_dynamic_vals)
+        g_hash_table_destroy(_extcap_prefs_dynamic_vals);
+
+    if (_loaded_interfaces)
+        g_hash_table_destroy(_loaded_interfaces);
+
+    if (_tool_for_ifname)
+        g_hash_table_destroy(_tool_for_ifname);
+}
+
+/**
+ * Obtains a pointer which can store a value for the given preference name.
+ * The preference name that can be passed to the prefs API is stored into
+ * 'prefs_name'.
+ *
+ * Extcap interfaces (and their preferences) are dynamic, they can be created
+ * and destroyed at will. Thus their data structures are insufficient to pass to
+ * the preferences APIs which require pointers which are valid until the
+ * preferences are removed (at exit).
+ */
+static gchar **extcap_prefs_dynamic_valptr(const char *name, char **pref_name)
+{
+    gchar **valp;
+    if (!_extcap_prefs_dynamic_vals)
+    {
+        /* Initialize table only as needed, most preferences are not dynamic */
+        _extcap_prefs_dynamic_vals = g_hash_table_new_full(g_str_hash, g_str_equal,
+                                    g_free, g_free);
+    }
+    if (!g_hash_table_lookup_extended(_extcap_prefs_dynamic_vals, name,
+                                      (gpointer *)pref_name, (gpointer *)&valp))
+    {
+        /* New dynamic pref, allocate, initialize and store. */
+        valp = g_new0(gchar *, 1);
+        *pref_name = g_strdup(name);
+        g_hash_table_insert(_extcap_prefs_dynamic_vals, *pref_name, valp);
+    }
+    return valp;
+}
+
+void extcap_free_if_configuration(GList *list, gboolean free_args)
+{
+    GList *elem, *sl;
+
+    for (elem = g_list_first(list); elem; elem = elem->next)
+    {
+        if (elem->data != NULL)
+        {
+            sl = g_list_first((GList *)elem->data);
+            if (free_args)
+            {
+                extcap_free_arg_list(sl);
+            }
+            else
+            {
+                g_list_free(sl);
+            }
+        }
+    }
+    g_list_free(list);
+}
+
+struct preference *
+extcap_pref_for_argument(const gchar *ifname, struct _extcap_arg *arg)
+{
+    struct preference *pref = NULL;
+
+    extcap_ensure_all_interfaces_loaded();
+
+    GRegex *regex_name = g_regex_new("[-]+", G_REGEX_RAW, (GRegexMatchFlags) 0, NULL);
+    GRegex *regex_ifname = g_regex_new("(?![a-zA-Z0-9_]).", G_REGEX_RAW, (GRegexMatchFlags) 0, NULL);
+    if (regex_name && regex_ifname)
+    {
+        if (prefs_find_module("extcap"))
+        {
+            gchar *pref_name = g_regex_replace(regex_name, arg->call, strlen(arg->call), 0, "", (GRegexMatchFlags) 0, NULL);
+            gchar *ifname_underscore = g_regex_replace(regex_ifname, ifname, strlen(ifname), 0, "_", (GRegexMatchFlags) 0, NULL);
+            gchar *ifname_lowercase = g_ascii_strdown(ifname_underscore, -1);
+            gchar *pref_ifname = g_strconcat(ifname_lowercase, ".", pref_name, NULL);
+
+            pref = prefs_find_preference(prefs_find_module("extcap"), pref_ifname);
+
+            g_free(pref_name);
+            g_free(ifname_underscore);
+            g_free(ifname_lowercase);
+            g_free(pref_ifname);
+        }
+    }
+    if (regex_name)
+    {
+        g_regex_unref(regex_name);
+    }
+    if (regex_ifname)
+    {
+        g_regex_unref(regex_ifname);
+    }
+
+    return pref;
+}
+
+static gboolean cb_preference(extcap_callback_info_t cb_info)
+{
+    GList *arguments = NULL;
+    GList **il = (GList **) cb_info.data;
+    module_t *dev_module = NULL;
+
+    arguments = extcap_parse_args(cb_info.output);
+
+    dev_module = prefs_find_module("extcap");
+
+    if (dev_module)
+    {
+        GList *walker = arguments;
+
+        GRegex *regex_name = g_regex_new("[-]+", G_REGEX_RAW, (GRegexMatchFlags) 0, NULL);
+        GRegex *regex_ifname = g_regex_new("(?![a-zA-Z0-9_]).", G_REGEX_RAW, (GRegexMatchFlags) 0, NULL);
+        if (regex_name && regex_ifname)
+        {
+            while (walker != NULL)
+            {
+                extcap_arg *arg = (extcap_arg *)walker->data;
+                arg->device_name = g_strdup(cb_info.ifname);
+
+                if (arg->save)
+                {
+                    gchar *pref_name = g_regex_replace(regex_name, arg->call, strlen(arg->call), 0, "", (GRegexMatchFlags) 0, NULL);
+                    gchar *ifname_underscore = g_regex_replace(regex_ifname, cb_info.ifname, strlen(cb_info.ifname), 0, "_", (GRegexMatchFlags) 0, NULL);
+                    gchar *ifname_lowercase = g_ascii_strdown(ifname_underscore, -1);
+                    gchar *pref_ifname = g_strconcat(ifname_lowercase, ".", pref_name, NULL);
+
+                    if (prefs_find_preference(dev_module, pref_ifname) == NULL)
+                    {
+                        char *pref_name_for_prefs;
+                        char *pref_title = wmem_strdup(wmem_epan_scope(), arg->display);
+
+                        arg->pref_valptr = extcap_prefs_dynamic_valptr(pref_ifname, &pref_name_for_prefs);
+                        /* Set an initial value if any (the string will be copied at registration) */
+                        if (arg->default_complex)
+                        {
+                            *arg->pref_valptr = arg->default_complex->_val;
+                        }
+
+                        if (arg->arg_type == EXTCAP_ARG_PASSWORD)
+                        {
+                            prefs_register_password_preference(dev_module, pref_name_for_prefs,
+                                                         pref_title, pref_title, (const char **)arg->pref_valptr);
+                        } else {
+                            prefs_register_string_preference(dev_module, pref_name_for_prefs,
+                                                         pref_title, pref_title, (const char **)arg->pref_valptr);
+                        }
+                    }
+                    else
+                    {
+                        /* Been here before, restore stored value */
+                        if (arg->pref_valptr == NULL)
+                        {
+                            arg->pref_valptr = (gchar**)g_hash_table_lookup(_extcap_prefs_dynamic_vals, pref_ifname);
+                        }
+                    }
+
+                    g_free(pref_name);
+                    g_free(ifname_underscore);
+                    g_free(ifname_lowercase);
+                    g_free(pref_ifname);
+                }
+
+                walker = g_list_next(walker);
+            }
+        }
+        if (regex_name)
+        {
+            g_regex_unref(regex_name);
+        }
+        if (regex_ifname)
+        {
+            g_regex_unref(regex_ifname);
+        }
+    }
+
+    *il = g_list_append(*il, arguments);
+
+    /* By returning false, extcap_foreach will break on first found */
+    return TRUE;
+}
+
+GList *
+extcap_get_if_configuration(const char *ifname)
+{
+    GList * arguments = NULL;
+    GList *ret = NULL;
+
+    extcap_ensure_all_interfaces_loaded();
+
+    extcap_interface *interface = extcap_find_interface_for_ifname(ifname);
+    if (interface)
+    {
+        ws_debug("Extcap path %s", get_extcap_dir());
+
+        arguments = g_list_append(arguments, g_strdup(EXTCAP_ARGUMENT_CONFIG));
+        arguments = g_list_append(arguments, g_strdup(EXTCAP_ARGUMENT_INTERFACE));
+        arguments = g_list_append(arguments, g_strdup(ifname));
+
+        extcap_run_one(interface, arguments, cb_preference, &ret, NULL);
+
+        g_list_free_full(arguments, g_free);
+    }
+
+    return ret;
+}
+
+static gboolean cb_reload_preference(extcap_callback_info_t cb_info)
+{
+    GList *arguments = NULL, * walker = NULL;
+    GList **il = (GList **) cb_info.data;
+
+    arguments = extcap_parse_values(cb_info.output);
+
+    walker = g_list_first(arguments);
+    while (walker != NULL)
+    {
+        extcap_value * val = (extcap_value *)walker->data;
+        *il = g_list_append(*il, val);
+        walker = g_list_next(walker);
+    }
+    g_list_free(arguments);
+
+    /* By returning false, extcap_foreach will break on first found */
+    return FALSE;
+}
+
+GList *
+extcap_get_if_configuration_values(const char * ifname, const char * argname, GHashTable *arguments)
+{
+    GList * args = NULL;
+    GList *ret = NULL;
+
+    extcap_ensure_all_interfaces_loaded();
+
+    extcap_interface *interface = extcap_find_interface_for_ifname(ifname);
+    if (interface)
+    {
+        ws_debug("Extcap path %s", get_extcap_dir());
+
+        args = g_list_append(args, g_strdup(EXTCAP_ARGUMENT_CONFIG));
+        args = g_list_append(args, g_strdup(EXTCAP_ARGUMENT_INTERFACE));
+        args = g_list_append(args, g_strdup(ifname));
+        args = g_list_append(args, g_strdup(EXTCAP_ARGUMENT_RELOAD_OPTION));
+        args = g_list_append(args, g_strdup(argname));
+
+        if ( arguments )
+        {
+            GList * keys = g_hash_table_get_keys(arguments);
+            GList * walker = g_list_first(keys);
+            while ( walker )
+            {
+                const gchar * key_data = (const gchar *)walker->data;
+                args = g_list_append(args, g_strdup(key_data));
+                args = g_list_append(args, g_strdup((const gchar *)g_hash_table_lookup(arguments, key_data)));
+                walker = g_list_next(walker);
+            }
+            g_list_free(keys);
+        }
+
+        extcap_run_one(interface, args, cb_reload_preference, &ret, NULL);
+
+        g_list_free_full(args, g_free);
+    }
+
+    return ret;
+}
+
+gboolean
+_extcap_requires_configuration_int(const char *ifname, gboolean check_required)
+{
+    GList *arguments = 0;
+    GList *walker = 0, * item = 0;
+    gboolean found = FALSE;
+
+    extcap_ensure_all_interfaces_loaded();
+
+    arguments = extcap_get_if_configuration(ifname);
+    walker = g_list_first(arguments);
+
+    while (walker != NULL && !found)
+    {
+        item = g_list_first((GList *)(walker->data));
+        while (item != NULL && !found)
+        {
+            if ((extcap_arg *)(item->data) != NULL)
+            {
+                extcap_arg *arg = (extcap_arg *)(item->data);
+                /* Should required options be present, or any kind of options */
+                if (!check_required)
+                {
+                    found = TRUE;
+                }
+                /* Following branch is executed when check of required items is requested */
+                else if (arg->is_required)
+                {
+                    const gchar *stored = NULL;
+                    const gchar *defval = NULL;
+
+                    if (arg->pref_valptr != NULL)
+                    {
+                        stored = *arg->pref_valptr;
+                    }
+
+                    if (arg->default_complex != NULL && arg->default_complex->_val != NULL)
+                    {
+                        defval = arg->default_complex->_val;
+                    }
+
+                    if (arg->is_required)
+                    {
+                        if (!defval && (!stored || !*stored))
+                        {
+                            found = TRUE;
+                        }
+                    }
+
+                    if (arg->arg_type == EXTCAP_ARG_FILESELECT)
+                    {
+                        if (arg->fileexists && !(file_exists(defval) || file_exists(stored)))
+                        {
+                            found = TRUE;
+                        }
+                    }
+                }
+            }
+
+            item = item->next;
+        }
+        walker = walker->next;
+    }
+    extcap_free_if_configuration(arguments, TRUE);
+
+    return found;
+}
+
+gboolean
+extcap_has_configuration(const char *ifname)
+{
+  return _extcap_requires_configuration_int(ifname, FALSE);
+}
+
+gboolean
+extcap_requires_configuration(const char *ifname)
+{
+  return _extcap_requires_configuration_int(ifname, TRUE);
+}
+
+static gboolean cb_verify_filter(extcap_callback_info_t cb_info)
+{
+    extcap_filter_status *status = (extcap_filter_status *)cb_info.data;
+    size_t output_size, i;
+
+    output_size = strlen(cb_info.output);
+    if (output_size == 0) {
+        *status = EXTCAP_FILTER_VALID;
+    } else {
+        *status = EXTCAP_FILTER_INVALID;
+        for (i = 0; i < output_size; i++) {
+            if (cb_info.output[i] == '\n' || cb_info.output[i] == '\r') {
+                cb_info.output[i] = '\0';
+                break;
+            }
+        }
+        *cb_info.err_str = g_strdup(cb_info.output);
+    }
+
+    return TRUE;
+}
+
+extcap_filter_status
+extcap_verify_capture_filter(const char *ifname, const char *filter, gchar **err_str)
+{
+    GList * arguments = NULL;
+    extcap_filter_status status = EXTCAP_FILTER_UNKNOWN;
+
+    extcap_ensure_all_interfaces_loaded();
+
+    extcap_interface *interface = extcap_find_interface_for_ifname(ifname);
+    if (interface)
+    {
+        ws_debug("Extcap path %s", get_extcap_dir());
+
+        arguments = g_list_append(arguments, g_strdup(EXTCAP_ARGUMENT_CAPTURE_FILTER));
+        arguments = g_list_append(arguments, g_strdup(filter));
+        arguments = g_list_append(arguments, g_strdup(EXTCAP_ARGUMENT_INTERFACE));
+        arguments = g_list_append(arguments, g_strdup(ifname));
+
+        extcap_run_one(interface, arguments, cb_verify_filter, &status, err_str);
+        g_list_free_full(arguments, g_free);
+    }
+
+    return status;
+}
+
+gboolean
+extcap_has_toolbar(const char *ifname)
+{
+    if (!iface_toolbar_use())
+    {
+        return FALSE;
+    }
+
+    extcap_ensure_all_interfaces_loaded();
+
+    GList *toolbar_list = g_hash_table_get_values (_toolbars);
+    for (GList *walker = toolbar_list; walker; walker = walker->next)
+    {
+        iface_toolbar *toolbar = (iface_toolbar *) walker->data;
+        if (g_list_find_custom(toolbar->ifnames, ifname, (GCompareFunc) g_strcmp0))
+        {
+            g_list_free(toolbar_list);
+            return TRUE;
+        }
+    }
+
+    g_list_free(toolbar_list);
+    return FALSE;
+}
+
+#ifdef HAVE_LIBPCAP
+static gboolean extcap_terminate_cb(gpointer user_data)
+{
+    capture_session *cap_session = (capture_session *)user_data;
+    capture_options *capture_opts = cap_session->capture_opts;
+    interface_options *interface_opts;
+    guint icnt;
+    gboolean all_finished = TRUE;
+
+    for (icnt = 0; icnt < capture_opts->ifaces->len; icnt++)
+    {
+        interface_opts = &g_array_index(capture_opts->ifaces, interface_options,
+                                       icnt);
+
+        /* skip native interfaces */
+        if (interface_opts->if_type != IF_EXTCAP)
+        {
+            continue;
+        }
+
+        if (interface_opts->extcap_pid != WS_INVALID_PID)
+        {
+#ifdef _WIN32
+            TerminateProcess(interface_opts->extcap_pid, 0);
+#else
+            kill(interface_opts->extcap_pid, SIGKILL);
+#endif
+            all_finished = FALSE;
+        }
+
+        /* Do not care about stdout/stderr anymore */
+        if (interface_opts->extcap_stdout_watch > 0)
+        {
+            g_source_remove(interface_opts->extcap_stdout_watch);
+            interface_opts->extcap_stdout_watch = 0;
+        }
+
+        if (interface_opts->extcap_stderr_watch > 0)
+        {
+            g_source_remove(interface_opts->extcap_stderr_watch);
+            interface_opts->extcap_stderr_watch = 0;
+        }
+    }
+
+    capture_opts->wait_for_extcap_cbs = TRUE;
+    capture_opts->extcap_terminate_id = 0;
+    if (all_finished)
+    {
+        capture_process_finished(cap_session);
+    }
+
+    return G_SOURCE_REMOVE;
+}
+
+void extcap_request_stop(capture_session *cap_session)
+{
+    capture_options *capture_opts = cap_session->capture_opts;
+    interface_options *interface_opts;
+    guint icnt = 0;
+
+    if (capture_opts->extcap_terminate_id > 0)
+    {
+        /* Already requested, do not extend timeout */
+        return;
+    }
+
+    if (capture_opts->wait_for_extcap_cbs)
+    {
+        /* Terminate callback was called, waiting for child callbacks */
+        return;
+    }
+
+    if (extcap_session_stop(cap_session))
+    {
+        /* Nothing left to do, all extcaps have fully finished */
+        return;
+    }
+
+    for (icnt = 0; icnt < capture_opts->ifaces->len; icnt++)
+    {
+        interface_opts = &g_array_index(capture_opts->ifaces, interface_options,
+                                       icnt);
+
+        /* skip native interfaces */
+        if (interface_opts->if_type != IF_EXTCAP)
+        {
+            continue;
+        }
+
+        ws_debug("Extcap [%s] - Requesting stop PID: %"PRIdMAX, interface_opts->name,
+              (intmax_t)interface_opts->extcap_pid);
+
+#ifndef _WIN32
+        if (interface_opts->extcap_pid != WS_INVALID_PID)
+        {
+            kill(interface_opts->extcap_pid, SIGTERM);
+        }
+#endif
+    }
+
+    capture_opts->extcap_terminate_id =
+        g_timeout_add_seconds(EXTCAP_CLEANUP_TIMEOUT, extcap_terminate_cb, cap_session);
+}
+
+static gboolean
+extcap_add_arg_and_remove_cb(gpointer key, gpointer value, gpointer data)
+{
+    GPtrArray *args = (GPtrArray *)data;
+
+    if (key != NULL)
+    {
+        g_ptr_array_add(args, g_strdup((const gchar *)key));
+
+        if (value != NULL)
+        {
+            g_ptr_array_add(args, g_strdup((const gchar *)value));
+        }
+
+        return TRUE;
+    }
+
+    return FALSE;
+}
+
+gboolean extcap_session_stop(capture_session *cap_session)
+{
+    capture_options *capture_opts = cap_session->capture_opts;
+    interface_options *interface_opts;
+    guint i;
+
+    for (i = 0; i < capture_opts->ifaces->len; i++)
+    {
+        interface_opts = &g_array_index(capture_opts->ifaces, interface_options, i);
+        if (interface_opts->if_type != IF_EXTCAP)
+        {
+            continue;
+        }
+
+        if ((interface_opts->extcap_pid != WS_INVALID_PID) ||
+            (interface_opts->extcap_stdout_watch > 0) ||
+            (interface_opts->extcap_stderr_watch > 0))
+        {
+            /* Capture session is not finished, wait for remaining watches */
+            return FALSE;
+        }
+
+        g_free(interface_opts->extcap_pipedata);
+        interface_opts->extcap_pipedata = NULL;
+
+#ifdef _WIN32
+        if (interface_opts->extcap_pipe_h != INVALID_HANDLE_VALUE)
+        {
+            ws_debug("Extcap [%s] - Closing pipe", interface_opts->name);
+            FlushFileBuffers(interface_opts->extcap_pipe_h);
+            DisconnectNamedPipe(interface_opts->extcap_pipe_h);
+            CloseHandle(interface_opts->extcap_pipe_h);
+            interface_opts->extcap_pipe_h = INVALID_HANDLE_VALUE;
+        }
+        if (interface_opts->extcap_control_in_h != INVALID_HANDLE_VALUE)
+        {
+            ws_debug("Extcap [%s] - Closing control_in pipe", interface_opts->name);
+            FlushFileBuffers(interface_opts->extcap_control_in_h);
+            DisconnectNamedPipe(interface_opts->extcap_control_in_h);
+            CloseHandle(interface_opts->extcap_control_in_h);
+            interface_opts->extcap_control_in_h = INVALID_HANDLE_VALUE;
+        }
+        if (interface_opts->extcap_control_out_h != INVALID_HANDLE_VALUE)
+        {
+            ws_debug("Extcap [%s] - Closing control_out pipe", interface_opts->name);
+            FlushFileBuffers(interface_opts->extcap_control_out_h);
+            DisconnectNamedPipe(interface_opts->extcap_control_out_h);
+            CloseHandle(interface_opts->extcap_control_out_h);
+            interface_opts->extcap_control_out_h = INVALID_HANDLE_VALUE;
+        }
+#else
+        if (interface_opts->extcap_fifo != NULL && file_exists(interface_opts->extcap_fifo))
+        {
+            /* If extcap didn't open the fifo, dumpcap would be waiting on it
+             * until user manually stops capture. Simply open and close fifo
+             * here to let dumpcap return from the select() call. This has no
+             * effect if dumpcap is not waiting.
+             */
+            int fd = ws_open(interface_opts->extcap_fifo, O_WRONLY|O_NONBLOCK, 0000);
+            if (fd != -1) {
+                close(fd);
+            }
+            /* the fifo will not be freed here, but with the other capture_opts in capture_sync */
+            ws_unlink(interface_opts->extcap_fifo);
+            get_dirname(interface_opts->extcap_fifo);
+            rmdir(interface_opts->extcap_fifo);
+            interface_opts->extcap_fifo = NULL;
+        }
+        if (interface_opts->extcap_control_in && file_exists(interface_opts->extcap_control_in))
+        {
+            ws_unlink(interface_opts->extcap_control_in);
+            interface_opts->extcap_control_in = NULL;
+        }
+        if (interface_opts->extcap_control_out && file_exists(interface_opts->extcap_control_out))
+        {
+            ws_unlink(interface_opts->extcap_control_out);
+            interface_opts->extcap_control_out = NULL;
+        }
+#endif
+    }
+
+    /* All child processes finished */
+    capture_opts->wait_for_extcap_cbs = FALSE;
+    if (capture_opts->extcap_terminate_id > 0)
+    {
+        g_source_remove(capture_opts->extcap_terminate_id);
+        capture_opts->extcap_terminate_id = 0;
+    }
+
+    /* Nothing left to do, do not prevent capture session stop */
+    return TRUE;
+}
+
+static void
+extcap_watch_removed(capture_session *cap_session, interface_options *interface_opts)
+{
+    if ((interface_opts->extcap_pid == WS_INVALID_PID) &&
+        (interface_opts->extcap_stdout_watch == 0) &&
+        (interface_opts->extcap_stderr_watch == 0))
+    {
+        /* Close session if this was the last remaining process */
+        capture_process_finished(cap_session);
+    }
+}
+
+static interface_options *
+extcap_find_channel_interface(capture_session *cap_session, GIOChannel *source)
+{
+    capture_options *capture_opts = cap_session->capture_opts;
+    interface_options *interface_opts;
+    guint i;
+
+    for (i = 0; i < capture_opts->ifaces->len; i++)
+    {
+        ws_pipe_t *pipedata;
+        interface_opts = &g_array_index(capture_opts->ifaces, interface_options, i);
+        pipedata = (ws_pipe_t *)interface_opts->extcap_pipedata;
+        if (pipedata &&
+            ((pipedata->stdout_io == source) || (pipedata->stderr_io == source)))
+        {
+            return interface_opts;
+        }
+    }
+
+    ws_assert_not_reached();
+}
+
+static gboolean
+extcap_stdout_cb(GIOChannel *source, GIOCondition condition _U_, gpointer data)
+{
+    capture_session *cap_session = (capture_session *)data;
+    interface_options *interface_opts = extcap_find_channel_interface(cap_session, source);
+    char buf[128];
+    gsize bytes_read = 0;
+    GIOStatus status = G_IO_STATUS_EOF;
+
+    /* Discard data to prevent child process hanging on stdout write */
+    if (condition & G_IO_IN)
+    {
+        status = g_io_channel_read_chars(source, buf, sizeof(buf), &bytes_read, NULL);
+    }
+
+    if ((bytes_read == 0) || (status != G_IO_STATUS_NORMAL))
+    {
+        interface_opts->extcap_stdout_watch = 0;
+        extcap_watch_removed(cap_session, interface_opts);
+        return G_SOURCE_REMOVE;
+    }
+    return G_SOURCE_CONTINUE;
+}
+
+static gboolean
+extcap_stderr_cb(GIOChannel *source, GIOCondition condition, gpointer data)
+{
+    capture_session *cap_session = (capture_session *)data;
+    interface_options *interface_opts = extcap_find_channel_interface(cap_session, source);
+    char buf[128];
+    gsize bytes_read = 0;
+    GIOStatus status = G_IO_STATUS_EOF;
+
+    if (condition & G_IO_IN)
+    {
+        status = g_io_channel_read_chars(source, buf, sizeof(buf), &bytes_read, NULL);
+    }
+
+#define STDERR_BUFFER_SIZE 1024
+    if (bytes_read > 0)
+    {
+        if (interface_opts->extcap_stderr == NULL)
+        {
+            interface_opts->extcap_stderr = g_string_new_len(buf, bytes_read);
+        }
+        else
+        {
+            gssize remaining = STDERR_BUFFER_SIZE - interface_opts->extcap_stderr->len;
+            if (remaining > 0)
+            {
+                gssize bytes = bytes_read;
+                bytes = MIN(bytes, remaining);
+                g_string_append_len(interface_opts->extcap_stderr, buf, bytes);
+            }
+        }
+    }
+
+    if ((bytes_read == 0) || (status != G_IO_STATUS_NORMAL))
+    {
+        interface_opts->extcap_stderr_watch = 0;
+        extcap_watch_removed(cap_session, interface_opts);
+        return G_SOURCE_REMOVE;
+    }
+    return G_SOURCE_CONTINUE;
+}
+
+static void extcap_child_watch_cb(GPid pid, gint status _U_, gpointer user_data)
+{
+    guint i;
+    interface_options *interface_opts;
+    capture_session *cap_session = (capture_session *)(user_data);
+    capture_options *capture_opts = cap_session->capture_opts;
+
+    /* Close handle to child process. */
+    g_spawn_close_pid(pid);
+
+    /* Update extcap_pid in interface options structure. */
+    for (i = 0; i < capture_opts->ifaces->len; i++)
+    {
+        interface_opts = &g_array_index(capture_opts->ifaces, interface_options, i);
+        if (interface_opts->extcap_pid == pid)
+        {
+            ws_debug("Extcap [%s] - Closing spawned PID: %"PRIdMAX, interface_opts->name,
+                     (intmax_t)interface_opts->extcap_pid);
+            interface_opts->extcap_pid = WS_INVALID_PID;
+            extcap_watch_removed(cap_session, interface_opts);
+            break;
+        }
+    }
+}
+
+static
+GPtrArray *extcap_prepare_arguments(interface_options *interface_opts)
+{
+    GPtrArray *result = NULL;
+
+    if (interface_opts->if_type == IF_EXTCAP)
+    {
+        result = g_ptr_array_new();
+
+#define add_arg(X) g_ptr_array_add(result, g_strdup(X))
+
+        add_arg(interface_opts->extcap);
+        add_arg(EXTCAP_ARGUMENT_RUN_CAPTURE);
+        add_arg(EXTCAP_ARGUMENT_INTERFACE);
+        add_arg(interface_opts->name);
+        if (interface_opts->cfilter && strlen(interface_opts->cfilter) > 0)
+        {
+            add_arg(EXTCAP_ARGUMENT_CAPTURE_FILTER);
+            add_arg(interface_opts->cfilter);
+        }
+        add_arg(EXTCAP_ARGUMENT_RUN_PIPE);
+        add_arg(interface_opts->extcap_fifo);
+        if (interface_opts->extcap_control_in)
+        {
+            add_arg(EXTCAP_ARGUMENT_CONTROL_OUT);
+            add_arg(interface_opts->extcap_control_in);
+        }
+        if (interface_opts->extcap_control_out)
+        {
+            add_arg(EXTCAP_ARGUMENT_CONTROL_IN);
+            add_arg(interface_opts->extcap_control_out);
+        }
+        if (interface_opts->extcap_args == NULL || g_hash_table_size(interface_opts->extcap_args) == 0)
+        {
+            /* User did not perform interface configuration.
+             *
+             * Check if there are any boolean flags that are set by default
+             * and hence their argument should be added.
+             */
+            GList *arglist;
+            GList *elem;
+
+            arglist = extcap_get_if_configuration(interface_opts->name);
+            for (elem = g_list_first(arglist); elem; elem = elem->next)
+            {
+                GList *arg_list;
+                extcap_arg *arg_iter;
+
+                if (elem->data == NULL)
+                {
+                    continue;
+                }
+
+                arg_list = g_list_first((GList *)elem->data);
+                while (arg_list != NULL)
+                {
+                    const gchar *stored = NULL;
+                    /* In case of boolflags only first element in arg_list is relevant. */
+                    arg_iter = (extcap_arg *)(arg_list->data);
+                    if (arg_iter->pref_valptr != NULL)
+                    {
+                        stored = *arg_iter->pref_valptr;
+                    }
+
+                    if (arg_iter->arg_type == EXTCAP_ARG_BOOLFLAG)
+                    {
+                        if (!stored && extcap_complex_get_bool(arg_iter->default_complex))
+                        {
+                            add_arg(arg_iter->call);
+                        }
+                        else if (g_strcmp0(stored, "true") == 0)
+                        {
+                            add_arg(arg_iter->call);
+                        }
+                    }
+                    else
+                    {
+                        if (stored && strlen(stored) > 0) {
+                            add_arg(arg_iter->call);
+                            add_arg(stored);
+                        }
+                    }
+
+                    arg_list = arg_list->next;
+                }
+            }
+
+            extcap_free_if_configuration(arglist, TRUE);
+        }
+        else
+        {
+            g_hash_table_foreach_remove(interface_opts->extcap_args, extcap_add_arg_and_remove_cb, result);
+        }
+        add_arg(NULL);
+#undef add_arg
+
+    }
+
+    return result;
+}
+
+static void ptr_array_free(gpointer data, gpointer user_data _U_)
+{
+    g_free(data);
+}
+
+#ifdef _WIN32
+static gboolean extcap_create_pipe(const gchar *ifname, gchar **fifo, HANDLE *handle_out, const gchar *pipe_prefix)
+{
+    gchar timestr[ 14 + 1 ];
+    time_t current_time;
+    gchar *pipename = NULL;
+    SECURITY_ATTRIBUTES security;
+
+    /* create pipename */
+    current_time = time(NULL);
+    /*
+     * XXX - we trust Windows not to return a time before the Epoch here,
+     * so we won't get a null pointer back from localtime().
+     */
+    strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(&current_time));
+    pipename = g_strconcat("\\\\.\\pipe\\", pipe_prefix, "_", ifname, "_", timestr, NULL);
+
+    /* Security struct to enable Inheritable HANDLE */
+    memset(&security, 0, sizeof(SECURITY_ATTRIBUTES));
+    security.nLength = sizeof(SECURITY_ATTRIBUTES);
+    security.bInheritHandle = FALSE;
+    security.lpSecurityDescriptor = NULL;
+
+    /* create a namedPipe */
+    *handle_out = CreateNamedPipe(
+                 utf_8to16(pipename),
+                 PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED,
+                 PIPE_TYPE_BYTE | PIPE_READMODE_BYTE | PIPE_WAIT,
+                 1, 65536, 65536,
+                 300,
+                 &security);
+
+    if (*handle_out == INVALID_HANDLE_VALUE)
+    {
+        ws_debug("Error creating pipe => (%ld)", GetLastError());
+        g_free (pipename);
+        return FALSE;
+    }
+    else
+    {
+        ws_debug("Wireshark Created pipe =>(%s) handle (%" PRIuMAX ")", pipename, (uintmax_t)*handle_out);
+        *fifo = g_strdup(pipename);
+    }
+
+    return TRUE;
+}
+#else
+static gboolean extcap_create_pipe(const gchar *ifname, gchar **fifo, const gchar *temp_dir, const gchar *pipe_prefix)
+{
+    gchar *subdir_tmpl = g_strdup_printf("%s_%s_XXXXXX", pipe_prefix, ifname);
+    gchar *temp_subdir = create_tempdir(temp_dir, subdir_tmpl, NULL);
+
+    g_free(subdir_tmpl);
+    if (temp_subdir == NULL)
+    {
+        return FALSE;
+    }
+
+    gchar *fifo_path = g_build_path(G_DIR_SEPARATOR_S, temp_subdir, "fifo", NULL);
+    g_free(temp_subdir);
+
+    ws_debug("Extcap - Creating fifo: %s", fifo_path);
+
+    if (mkfifo(fifo_path, 0600) == 0)
+    {
+        *fifo = fifo_path;
+    }
+    else
+    {
+        g_free(fifo_path);
+    }
+    return TRUE;
+}
+#endif
+
+/* call mkfifo for each extcap,
+ * returns FALSE if there's an error creating a FIFO */
+gboolean
+extcap_init_interfaces(capture_session *cap_session)
+{
+    capture_options *capture_opts = cap_session->capture_opts;
+    guint i;
+    interface_options *interface_opts;
+    ws_pipe_t *pipedata;
+
+    extcap_ensure_all_interfaces_loaded();
+
+    for (i = 0; i < capture_opts->ifaces->len; i++)
+    {
+        GPtrArray *args = NULL;
+        GPid pid = WS_INVALID_PID;
+
+        interface_opts = &g_array_index(capture_opts->ifaces, interface_options, i);
+
+        /* skip native interfaces */
+        if (interface_opts->if_type != IF_EXTCAP)
+        {
+            continue;
+        }
+
+        /* create control pipes if having toolbar */
+        if (extcap_has_toolbar(interface_opts->name))
+        {
+            extcap_create_pipe(interface_opts->name, &interface_opts->extcap_control_in,
+#ifdef _WIN32
+                               &interface_opts->extcap_control_in_h,
+#else
+                               capture_opts->temp_dir,
+#endif
+                               EXTCAP_CONTROL_IN_PREFIX);
+            extcap_create_pipe(interface_opts->name, &interface_opts->extcap_control_out,
+#ifdef _WIN32
+                               &interface_opts->extcap_control_out_h,
+#else
+                               capture_opts->temp_dir,
+#endif
+                               EXTCAP_CONTROL_OUT_PREFIX);
+        }
+
+        /* create pipe for fifo */
+        if (!extcap_create_pipe(interface_opts->name, &interface_opts->extcap_fifo,
+#ifdef _WIN32
+                                &interface_opts->extcap_pipe_h,
+#else
+                               capture_opts->temp_dir,
+#endif
+                                EXTCAP_PIPE_PREFIX))
+        {
+            return FALSE;
+        }
+
+
+        /* Create extcap call */
+        args = extcap_prepare_arguments(interface_opts);
+
+        pipedata = g_new0(ws_pipe_t, 1);
+
+        pid = ws_pipe_spawn_async(pipedata, args);
+
+        g_ptr_array_foreach(args, ptr_array_free, NULL);
+        g_ptr_array_free(args, TRUE);
+
+        if (pid == WS_INVALID_PID)
+        {
+            g_free(pipedata);
+            continue;
+        }
+
+        g_io_channel_unref(pipedata->stdin_io);
+        pipedata->stdin_io = NULL;
+        interface_opts->extcap_pid = pid;
+
+        g_child_watch_add_full(G_PRIORITY_HIGH, pid, extcap_child_watch_cb,
+                               (gpointer)cap_session, NULL);
+        interface_opts->extcap_stdout_watch =
+            g_io_add_watch(pipedata->stdout_io, G_IO_IN | G_IO_HUP,
+                           extcap_stdout_cb, (gpointer)cap_session);
+        interface_opts->extcap_stderr_watch =
+            g_io_add_watch(pipedata->stderr_io, G_IO_IN | G_IO_HUP,
+                           extcap_stderr_cb, (gpointer)cap_session);
+
+        /* Pipedata pointers are only used to match GIOChannel to interface.
+         * GIOChannel watch holds the only remaining reference.
+         */
+        g_io_channel_unref(pipedata->stdout_io);
+        g_io_channel_unref(pipedata->stderr_io);
+
+#ifdef _WIN32
+        /* On Windows, wait for extcap to connect to named pipe.
+         * Some extcaps will present UAC screen to user.
+         * 30 second timeout should be reasonable timeout for extcap to
+         * connect to named pipe (including user interaction).
+         * Wait on multiple object in case of extcap termination
+         * without opening pipe.
+         */
+        if (pid != WS_INVALID_PID)
+        {
+            HANDLE pipe_handles[3];
+            int num_pipe_handles = 1;
+            pipe_handles[0] = interface_opts->extcap_pipe_h;
+
+            if (extcap_has_toolbar(interface_opts->name))
+            {
+                pipe_handles[1] = interface_opts->extcap_control_in_h;
+                pipe_handles[2] = interface_opts->extcap_control_out_h;
+                num_pipe_handles += 2;
+             }
+
+            ws_pipe_wait_for_pipe(pipe_handles, num_pipe_handles, pid);
+        }
+#endif
+
+        interface_opts->extcap_pipedata = (gpointer) pipedata;
+    }
+
+    return TRUE;
+}
+#endif /* HAVE_LIBPCAP */
+
+/************* EXTCAP LOAD INTERFACE LIST ***************
+ *
+ * The following code handles loading and reloading the interface list. It is explicitly
+ * kept separate from the rest
+ */
+
+
+static void
+extcap_free_interface_info(gpointer data)
+{
+    extcap_info *info = (extcap_info *)data;
+
+    g_free(info->basename);
+    g_free(info->full_path);
+    g_free(info->version);
+    g_free(info->help);
+
+    extcap_free_interfaces(info->interfaces);
+
+    g_free(info);
+}
+
+static extcap_info *
+extcap_ensure_interface(const gchar * toolname, gboolean create_if_nonexist)
+{
+    extcap_info * element = 0;
+
+    if ( prefs.capture_no_extcap )
+        return NULL;
+
+    if ( ! toolname )
+        return element;
+
+    if ( ! _loaded_interfaces )
+        _loaded_interfaces = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, extcap_free_interface);
+
+    element = (extcap_info *) g_hash_table_lookup(_loaded_interfaces, toolname );
+    if ( element )
+        return NULL;
+
+    if ( ! element && create_if_nonexist )
+    {
+        g_hash_table_insert(_loaded_interfaces, g_strdup(toolname), g_new0(extcap_info, 1));
+        element = (extcap_info *) g_hash_table_lookup(_loaded_interfaces, toolname );
+    }
+
+    return element;
+}
+
+extcap_info *
+extcap_get_tool_by_ifname(const gchar *ifname)
+{
+    extcap_ensure_all_interfaces_loaded();
+
+    if ( ifname && _tool_for_ifname )
+    {
+        gchar * toolname = (gchar *)g_hash_table_lookup(_tool_for_ifname, ifname);
+        if ( toolname )
+            return extcap_ensure_interface(toolname, FALSE);
+    }
+
+    return NULL;
+}
+
+extcap_info *
+extcap_get_tool_info(const gchar * toolname)
+{
+    extcap_ensure_all_interfaces_loaded();
+
+    return extcap_ensure_interface(toolname, FALSE);
+}
+
+static void remove_extcap_entry(gpointer entry, gpointer data _U_)
+{
+    extcap_interface *int_iter = (extcap_interface*)entry;
+
+    if (int_iter->if_type == EXTCAP_SENTENCE_EXTCAP)
+        extcap_free_interface(entry);
+}
+
+static void
+process_new_extcap(const char *extcap, char *output)
+{
+    GList * interfaces = NULL, * control_items = NULL, * walker = NULL;
+    extcap_interface * int_iter = NULL;
+    extcap_info * element = NULL;
+    iface_toolbar * toolbar_entry = NULL;
+    gchar * toolname = g_path_get_basename(extcap);
+
+    GList * interface_keys = g_hash_table_get_keys(_loaded_interfaces);
+
+    /* Load interfaces from utility */
+    interfaces = extcap_parse_interfaces(output, &control_items);
+
+    ws_debug("Loading interface list for %s ", extcap);
+
+    /* Seems, that there where no interfaces to be loaded */
+    if ( ! interfaces || g_list_length(interfaces) == 0 )
+    {
+        ws_debug("Cannot load interfaces for %s", extcap );
+        g_list_free(interface_keys);
+        g_free(toolname);
+        return;
+    }
+
+    /* Load or create the storage element for the tool */
+    element = extcap_ensure_interface(toolname, TRUE);
+    if ( element == NULL )
+    {
+        ws_warning("Cannot store interface %s, already loaded as personal plugin", extcap );
+        g_list_foreach(interfaces, remove_extcap_entry, NULL);
+        g_list_free(interfaces);
+        g_list_free(interface_keys);
+        g_free(toolname);
+        return;
+    }
+
+    if (control_items)
+    {
+        toolbar_entry = g_new0(iface_toolbar, 1);
+        toolbar_entry->controls = control_items;
+    }
+
+    walker = interfaces;
+    gchar* help = NULL;
+    while (walker != NULL)
+    {
+        int_iter = (extcap_interface *)walker->data;
+
+        if (int_iter->call != NULL)
+            ws_debug("Interface found %s\n", int_iter->call);
+
+        /* Help is not necessarily stored with the interface, but rather with the version string.
+         * As the version string always comes in front of the interfaces, this ensures, that it gets
+         * properly stored with the interface */
+        if (int_iter->if_type == EXTCAP_SENTENCE_EXTCAP)
+        {
+            if (int_iter->call != NULL)
+                ws_debug("  Extcap [%s] ", int_iter->call);
+
+            /* Only initialize values if none are set. Need to check only one element here */
+            if ( ! element->version )
+            {
+                element->version = g_strdup(int_iter->version);
+                element->basename = g_strdup(toolname);
+                element->full_path = g_strdup(extcap);
+                element->help = g_strdup(int_iter->help);
+            }
+
+            help = int_iter->help;
+            if (toolbar_entry)
+            {
+                toolbar_entry->menu_title = g_strdup(int_iter->display);
+                toolbar_entry->help = g_strdup(int_iter->help);
+            }
+
+            walker = g_list_next(walker);
+            continue;
+        }
+
+        /* Only interface definitions will be parsed here. help is already set by the extcap element,
+         * which makes it necessary to have version in the list before the interfaces. This is normally
+         * the case by design, but could be changed by separating the information in extcap-base. */
+        if ( int_iter->if_type == EXTCAP_SENTENCE_INTERFACE )
+        {
+            if ( g_list_find(interface_keys, int_iter->call) )
+            {
+                ws_warning("Extcap interface \"%s\" is already provided by \"%s\" ",
+                      int_iter->call, extcap_if_executable(int_iter->call));
+                walker = g_list_next(walker);
+                continue;
+            }
+
+            if ((int_iter->call != NULL) && (int_iter->display))
+                ws_debug("  Interface [%s] \"%s\" ", int_iter->call, int_iter->display);
+
+            int_iter->extcap_path = g_strdup(extcap);
+
+            /* Only set the help, if it exists and no parsed help information is present */
+            if ( ! int_iter->help && help )
+                int_iter->help = g_strdup(help);
+
+            element->interfaces = g_list_append(element->interfaces, int_iter);
+            g_hash_table_insert(_tool_for_ifname, g_strdup(int_iter->call), g_strdup(toolname));
+
+            if (toolbar_entry)
+            {
+                if (!toolbar_entry->menu_title)
+                {
+                    toolbar_entry->menu_title = g_strdup(int_iter->display);
+                }
+                toolbar_entry->ifnames = g_list_append(toolbar_entry->ifnames, g_strdup(int_iter->call));
+            }
+        }
+
+        walker = g_list_next(walker);
+    }
+
+    if (toolbar_entry && toolbar_entry->menu_title)
+    {
+        iface_toolbar_add(toolbar_entry);
+        if (extcap_iface_toolbar_add(extcap, toolbar_entry))
+        {
+            toolbar_entry = NULL;
+        }
+    }
+
+    extcap_free_toolbar(toolbar_entry);
+    g_list_foreach(interfaces, remove_extcap_entry, NULL);
+    g_list_free(interfaces);
+    g_list_free(interface_keys);
+    g_free(toolname);
+}
+
+
+/** Thread callback to save the output of a --extcap-config call. */
+static void
+extcap_process_config_cb(thread_pool_t *pool _U_, void *data, char *output)
+{
+    extcap_iface_info_t *iface_info = (extcap_iface_info_t *)data;
+    iface_info->output = output;
+}
+
+/**
+ * Thread callback to process discovered interfaces, scheduling more tasks to
+ * retrieve the configuration for each interface. Called once for every extcap
+ * program.
+ */
+static void
+extcap_process_interfaces_cb(thread_pool_t *pool, void *data, char *output)
+{
+    extcap_run_extcaps_info_t *info = (extcap_run_extcaps_info_t *)data;
+    guint i = 0;
+    guint num_interfaces = 0;
+
+    if (!output) {
+        // No interfaces available, nothing to do.
+        return;
+    }
+
+    // Save output for process_new_extcap.
+    info->output = output;
+
+    // Are there any interfaces to query information from?
+    GList *interfaces = extcap_parse_interfaces(output, NULL);
+    for (GList *iface = interfaces; iface; iface = g_list_next(iface)) {
+        extcap_interface *intf = (extcap_interface *)iface->data;
+        if (intf->if_type == EXTCAP_SENTENCE_INTERFACE) {
+            ++num_interfaces;
+        }
+    }
+    if (num_interfaces == 0) {
+        // nothing to do.
+        g_list_free_full(interfaces, extcap_free_interface);
+        return;
+    }
+
+    /* GSList is not thread-safe, so pre-allocate an array instead. */
+    info->iface_infos = g_new0(extcap_iface_info_t, num_interfaces);
+    info->num_interfaces = num_interfaces;
+
+    // Schedule new commands to retrieve the configuration.
+    for (GList *iface = interfaces; iface; iface = g_list_next(iface)) {
+        extcap_interface *intf = (extcap_interface *)iface->data;
+        if (intf->if_type != EXTCAP_SENTENCE_INTERFACE) {
+            continue;
+        }
+
+        const char *argv[] = {
+            EXTCAP_ARGUMENT_CONFIG,
+            EXTCAP_ARGUMENT_INTERFACE,
+            intf->call,
+            NULL
+        };
+        extcap_run_task_t *task = g_new0(extcap_run_task_t, 1);
+        extcap_iface_info_t *iface_info = &info->iface_infos[i++];
+
+        task->extcap_path = info->extcap_path;
+        task->argv = g_strdupv((char **)argv);
+        task->output_cb = extcap_process_config_cb;
+        task->data = iface_info;
+        iface_info->ifname = g_strdup(intf->call);
+
+        thread_pool_push(pool, task, NULL);
+    }
+    g_list_free_full(interfaces, extcap_free_interface);
+}
+
+/**
+ * Thread callback to check whether the new-style --list-interfaces call with an
+ * explicit function succeeded. If not, schedule a call without the new version
+ * argument.
+ */
+static void
+extcap_list_interfaces_cb(thread_pool_t *pool, void *data, char *output)
+{
+    extcap_run_extcaps_info_t *info = (extcap_run_extcaps_info_t *)data;
+
+    if (!output) {
+        /* No output available, schedule a fallback query. */
+        const char *argv[] = {
+            EXTCAP_ARGUMENT_LIST_INTERFACES,
+            NULL
+        };
+        extcap_run_task_t *task = g_new0(extcap_run_task_t, 1);
+
+        task->extcap_path = info->extcap_path;
+        task->argv = g_strdupv((char **)argv);
+        task->output_cb = extcap_process_interfaces_cb;
+        task->data = info;
+
+        thread_pool_push(pool, task, NULL);
+    } else {
+        extcap_process_interfaces_cb(pool, info, output);
+    }
+}
+
+
+/* Handles loading of the interfaces. */
+static void
+extcap_load_interface_list(void)
+{
+    if (prefs.capture_no_extcap)
+        return;
+
+    if (_toolbars)
+    {
+        // Remove existing interface toolbars here instead of in extcap_clear_interfaces()
+        // to avoid flicker in shown toolbars when refreshing interfaces.
+        GList *toolbar_list = g_hash_table_get_values (_toolbars);
+        for (GList *walker = toolbar_list; walker; walker = walker->next)
+        {
+            iface_toolbar *toolbar = (iface_toolbar *) walker->data;
+            iface_toolbar_remove(toolbar->menu_title);
+        }
+        g_list_free(toolbar_list);
+        g_hash_table_remove_all(_toolbars);
+    } else {
+        _toolbars = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, extcap_free_toolbar);
+    }
+
+    if (_loaded_interfaces == NULL)
+    {
+        int major = 0;
+        int minor = 0;
+        guint count = 0;
+        extcap_run_extcaps_info_t *infos;
+        GList *unused_arguments = NULL;
+
+        _loaded_interfaces = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, extcap_free_interface_info);
+        /* Cleanup lookup table */
+        if ( _tool_for_ifname )
+        {
+            g_hash_table_remove_all(_tool_for_ifname);
+            _tool_for_ifname = 0;
+        } else {
+            _tool_for_ifname = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, g_free);
+        }
+
+        get_ws_version_number(&major, &minor, NULL);
+        char *arg_version = ws_strdup_printf("%s=%d.%d", EXTCAP_ARGUMENT_VERSION, major, minor);
+        const char *argv[] = {
+            EXTCAP_ARGUMENT_LIST_INTERFACES,
+            arg_version,
+            NULL
+        };
+        infos = (extcap_run_extcaps_info_t *)extcap_run_all(argv,
+                extcap_list_interfaces_cb, sizeof(extcap_run_extcaps_info_t),
+                &count);
+        for (guint i = 0; i < count; i++) {
+            if (!infos[i].output) {
+                continue;
+            }
+
+            // Save new extcap and each discovered interface.
+            process_new_extcap(infos[i].extcap_path, infos[i].output);
+            for (guint j = 0; j < infos[i].num_interfaces; j++) {
+                extcap_iface_info_t *iface_info = &infos[i].iface_infos[j];
+
+                if (!iface_info->output) {
+                    continue;
+                }
+
+                extcap_callback_info_t cb_info = {
+                    .ifname = iface_info->ifname,
+                    .output = iface_info->output,
+                    .data = &unused_arguments,
+                };
+                cb_preference(cb_info);
+            }
+        }
+        /* XXX rework cb_preference such that this unused list can be removed. */
+        extcap_free_if_configuration(unused_arguments, TRUE);
+        extcap_free_extcaps_info_array(infos, count);
+        g_free(arg_version);
+    }
+}
+
+/*
+ * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=true:
+ */