Print extcap plugins with "tshark -G plugins".

This makes it match the "Plugins" tab of the "About" dialog.

While we're at it, use the same code to enumerate extcap plugins in that
dialog.

Change-Id: I50f402a7ab5d83d46baab070d145558ed8f688f4
Reviewed-on: https://code.wireshark.org/review/32589
Reviewed-by: Guy Harris <guy@alum.mit.edu>

extcap.c

@@ -40,6 +40,7 @@
 #include <wsutil/file_util.h>
 #include <wsutil/filesystem.h>
 #include <wsutil/ws_pipe.h>
+#include <wsutil/ws_printf.h>
 #include <wsutil/tempfile.h>
 
 #include "capture_opts.h"
@@ -151,7 +152,7 @@ thread_pool_wait(thread_pool_t *pool)
     g_mutex_clear(&pool->data_mutex);
 }
 
-GHashTable *
+static GHashTable *
 extcap_loaded_interfaces(void)
 {
     if (prefs.capture_no_extcap)
@@ -175,6 +176,53 @@ extcap_clear_interfaces(void)
     _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)
+{
+    GHashTable * tools = extcap_loaded_interfaces();
+    GPtrArray *tools_array = g_ptr_array_new();
+
+    if (tools && g_hash_table_size(tools) > 0) {
+        GList * walker = g_list_first(g_hash_table_get_keys(tools));
+        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_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_)
+{
+    ws_debug_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);
+}
+
 /**
  * Obtains a list of extcap program paths. Use g_slist_free_full(paths, g_free)
  * to destroy the list.
@@ -1937,10 +1985,7 @@ extcap_list_interfaces_cb(thread_pool_t *pool, void *data, char *output)
 }
 
 
-/* Handles loading of the interfaces.
- *
- * A list of interfaces can be obtained by calling \ref extcap_loaded_interfaces
- */
+/* Handles loading of the interfaces. */
 static void
 extcap_load_interface_list(void)
 {

extcap.h

@@ -20,6 +20,8 @@
 #include <wsutil/unicode-utils.h>
 #endif
 
+#include <wsutil/plugins.h>
+
 #include <ui/capture_ui_utils.h>
 
 /* As boolean flags will be allowed any form of yes, true or any number != 0 (or starting with 0)
@@ -87,14 +89,18 @@ extcap_get_tool_by_ifname(const gchar *ifname);
 gchar *
 extcap_get_help_for_ifname(const char *ifname);
 
-/* get a list of all available extcap executables and their interfaces */
-GHashTable *
-extcap_loaded_interfaces(void);
-
 /* remove all loaded interfaces */
 void
 extcap_clear_interfaces(void);
 
+/* get information about all available extcap executables */
+void
+extcap_get_descriptions(plugin_description_callback callback, void *callback_data);
+
+/* print information about all available extcap executables */
+void
+extcap_dump_all(void);
+
 /* returns the configuration for the given interface name, or an
  * empty list, if no configuration has been found
  * @param ifname the interface name

tshark.c

@@ -978,6 +978,7 @@ main(int argc, char *argv[])
 #ifdef HAVE_LUA
         wslua_plugins_dump_all();
 #endif
+        extcap_dump_all();
       }
       else if (strcmp(argv[2], "protocols") == 0)
         proto_registrar_dump_protocols();

ui/qt/about_dialog.cpp

@@ -132,18 +132,7 @@ PluginListModel::PluginListModel(QObject * parent) : AStringListListModel(parent
     wslua_plugins_get_descriptions(plugins_add_description, &plugin_data);
 #endif
 
-    GHashTable * tools = extcap_loaded_interfaces();
-    if (tools && g_hash_table_size(tools) > 0) {
-        GList * walker = g_list_first(g_hash_table_get_keys(tools));
-        while (walker && walker->data) {
-            extcap_info * tool = (extcap_info *)g_hash_table_lookup(tools, walker->data);
-            if (tool) {
-                QStringList plugin_row = QStringList() << tool->basename << tool->version << tr("extcap") << tool->full_path;
-                plugin_data << plugin_row;
-            }
-            walker = g_list_next(walker);
-        }
-    }
+    extcap_get_descriptions(plugins_add_description, &plugin_data);
 
     typeNames_ << QString("");
     foreach(QStringList row, plugin_data)