Lua: add plugin version info

Expose a "set_plugin_info" global function to set the Lua plugin's
version information. Also, put info about Lua scripts loaded from
the command-line into the help output, not just for scripts loaded
from plugin direvtories.

Bug: 11315
Change-Id: I8bc425ed1ed0dfdc1d05178754f44d44e0b209b5
Reviewed-on: https://code.wireshark.org/review/9593
Petri-Dish: Hadriel Kaplan <hadrielk@yahoo.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

epan/wslua/init_wslua.c

@@ -492,6 +492,7 @@ static void set_file_environment(const gchar* filename, const gchar* dirname) {
     g_free(personal);
 }
 
+
 /* If file_count > 0 then it's a command-line-added user script, and the count
  * represents which user script it is (first=1, second=2, etc.).
  * If dirname != NULL, then it's a user script and the dirname will get put in a file environment
@@ -545,6 +546,32 @@ static gboolean lua_load_script(const gchar* filename, const gchar* dirname, con
     }
 }
 
+/* This one is used to load the init.lua scripts, or anything else
+ * that shouldn't really be considered a real plugin.
+ */
+static gboolean lua_load_internal_script(const gchar* filename) {
+    return lua_load_script(filename, NULL, 0);
+}
+
+/* This one is used to load plugins: either from the plugin directories,
+ *   or from the command line.
+ */
+static gboolean lua_load_plugin_script(const gchar* name,
+                                       const gchar* filename,
+                                       const gchar* dirname,
+                                       const int file_count)
+{
+    if (lua_load_script(filename, dirname, file_count)) {
+        wslua_add_plugin(g_strdup(name),
+                         g_strdup(get_current_plugin_version()),
+                         g_strdup(filename));
+        clear_current_plugin_version();
+        return TRUE;
+    }
+    return FALSE;
+}
+
+
 static void basic_logger(const gchar *log_domain _U_,
                           GLogLevelFlags log_level _U_,
                           const gchar *message,
@@ -598,9 +625,7 @@ static int lua_load_plugins(const char *dirname, register_cb cb, gpointer client
                 if (!count_only) {
                     if (cb)
                         (*cb)(RA_LUA_PLUGINS, name, client_data);
-                    if (lua_load_script(filename, is_user ? dirname : NULL, 0)) {
-                        wslua_add_plugin(g_strdup(name), g_strdup(""), g_strdup(filename));
-                    }
+                    lua_load_plugin_script(name, filename, is_user ? dirname : NULL, 0);
                 }
                 plugins_counter++;
             }
@@ -840,7 +865,7 @@ int wslua_init(register_cb cb, gpointer client_data) {
     }
 
     if (( file_exists(filename))) {
-        lua_load_script(filename, NULL, 0);
+        lua_load_internal_script(filename);
     }
 
     g_free(filename);
@@ -875,7 +900,7 @@ int wslua_init(register_cb cb, gpointer client_data) {
         if ((file_exists(filename))) {
             if (cb)
                 (*cb)(RA_LUA_PLUGINS, get_basename(filename), client_data);
-            lua_load_script(filename, NULL, 0);
+            lua_load_internal_script(filename);
         }
         g_free(filename);
 
@@ -892,7 +917,10 @@ int wslua_init(register_cb cb, gpointer client_data) {
             if (cb)
                 (*cb)(RA_LUA_PLUGINS, get_basename(script_filename), client_data);
 
-            lua_load_script(script_filename, dname ? dname : "", file_count);
+            lua_load_plugin_script(ws_dir_get_name(script_filename),
+                                   script_filename,
+                                   dname ? dname : "",
+                                   file_count);
             file_count++;
             g_free(dirname);
         }

epan/wslua/wslua.h

@@ -730,6 +730,9 @@ extern int wslua_bin2hex(lua_State* L, const guint8* data, const guint len, cons
 extern int wslua_hex2bin(lua_State* L, const char* data, const guint len, const gchar* sep);
 extern int luaopen_rex_glib(lua_State *L);
 
+extern const gchar* get_current_plugin_version(void);
+extern void clear_current_plugin_version(void);
+
 #endif
 
 /*

epan/wslua/wslua_util.c

@@ -37,6 +37,70 @@ WSLUA_FUNCTION wslua_get_version(lua_State* L) { /* Gets a string of the Wiresha
     WSLUA_RETURN(1); /* version string */
 }
 
+
+static gchar* current_plugin_version = NULL;
+
+const gchar* get_current_plugin_version(void) {
+    return current_plugin_version ? current_plugin_version : "";
+}
+
+void clear_current_plugin_version(void) {
+    if (current_plugin_version != NULL) {
+        g_free(current_plugin_version);
+        current_plugin_version = NULL;
+    }
+}
+
+WSLUA_FUNCTION wslua_set_plugin_info(lua_State* L) {
+    /*  Set a Lua table with meta-data about the plugin, such as version.
+
+        The passed-in Lua table entries need to be keyed/indexed by the following:
+         * "version" with a string value identifying the plugin version (required)
+         * "description" with a string value describing the plugin (optional)
+         * "author" with a string value of the author's name(s) (optional)
+         * "repository" with a string value of a URL to a repository (optional)
+
+        Not all of the above key entries need to be in the table. The 'version'
+        entry is required, however. The others are not currently used for anything, but
+        might be in the future and thus using them might be useful. Table entries keyed
+        by other strings are ignored, and do not cause an error.
+
+        Example:
+        @code
+        local my_info = {
+            version = "1.0.1",
+            author = "Jane Doe",
+            repository = "https://github.com/octocat/Spoon-Knife"
+        }
+
+        set_plugin_info(my_info)
+        @endcode
+
+        @since 1.99.9
+     */
+#define WSLUA_ARG_set_plugin_info_TABLE 1 /* The Lua table of information. */
+
+    if ( lua_istable(L,WSLUA_ARG_set_plugin_info_TABLE) ) {
+        int top;
+        lua_getfield(L, WSLUA_ARG_set_plugin_info_TABLE, "version");
+        top = lua_gettop(L);
+        if (lua_isstring(L, top)) {
+            clear_current_plugin_version();
+            current_plugin_version = g_strdup( luaL_checkstring(L, top) );
+            /* pop the string */
+            lua_pop(L, 1);
+        }
+        else {
+            return luaL_error(L,"the Lua table must have a 'version' key entry with a string value");
+        }
+    } else {
+        return luaL_error(L,"a Lua table with at least a 'version' string entry");
+    }
+
+    return 0;
+}
+
+
 WSLUA_FUNCTION wslua_format_date(lua_State* LS) { /* Formats an absolute timestamp into a human readable date. */
 #define WSLUA_ARG_format_date_TIMESTAMP 1 /* A timestamp value to convert. */
     lua_Number timestamp = luaL_checknumber(LS,WSLUA_ARG_format_date_TIMESTAMP);