From e45dd45e7b3f7f97ad4437cd9044346fde622bd1 Mon Sep 17 00:00:00 2001
From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Tue, 5 Apr 2016 13:41:33 +0100
Subject: [PATCH] [Feature] Add on load hooks for rspamd_config

---
 src/libserver/cfg_file.h  |  7 +++++++
 src/libserver/cfg_utils.c | 18 ++++++++++++++++++
 src/lua/lua_config.c      | 27 +++++++++++++++++++++++++++
 3 files changed, 52 insertions(+)

diff --git a/src/libserver/cfg_file.h b/src/libserver/cfg_file.h
index 2dd6addcb..0986ed035 100644
--- a/src/libserver/cfg_file.h
+++ b/src/libserver/cfg_file.h
@@ -259,6 +259,11 @@ struct metric {
 	struct metric_action actions[METRIC_ACTION_MAX]; /**< all actions of the metric						*/
 };
 
+struct rspamd_config_post_load_script {
+	gint cbref;
+	struct rspamd_config_post_load_script *prev, *next;
+};
+
 /**
  * Structure that stores all config data
  */
@@ -395,6 +400,8 @@ struct rspamd_config {
 
 	GHashTable *trusted_keys;						/**< list of trusted public keys						*/
 
+	struct rspamd_config_post_load_script *on_load;	/**< list of scripts executed on config load			*/
+
 	ref_entry_t ref;								/**< reference counter									*/
 };
 
diff --git a/src/libserver/cfg_utils.c b/src/libserver/cfg_utils.c
index 0685dc800..279a1b357 100644
--- a/src/libserver/cfg_utils.c
+++ b/src/libserver/cfg_utils.c
@@ -616,6 +616,8 @@ rspamd_config_post_load (struct rspamd_config *cfg, gboolean validate_cache)
 	struct timespec ts;
 #endif
 	struct metric *def_metric;
+	struct rspamd_config_post_load_script *sc;
+	struct rspamd_config **pcfg;
 
 #ifdef HAVE_CLOCK_GETTIME
 #ifdef HAVE_CLOCK_PROCESS_CPUTIME_ID
@@ -688,6 +690,22 @@ rspamd_config_post_load (struct rspamd_config *cfg, gboolean validate_cache)
 	/* Config other libraries */
 	rspamd_config_libs (cfg->libs_ctx, cfg);
 
+	/* Execute post load scripts */
+	LL_FOREACH (cfg->on_load, sc) {
+		lua_rawgeti (cfg->lua_state, LUA_REGISTRYINDEX, sc->cbref);
+		pcfg = lua_newuserdata (cfg->lua_state, sizeof (*pcfg));
+		*pcfg = cfg;
+		rspamd_lua_setclass (cfg->lua_state, "rspamd{config}", -1);
+
+		if (lua_pcall (cfg->lua_state, 1, 0, 0) != 0) {
+			msg_err_config ("error executing post load code: %s",
+					lua_tostring (cfg->lua_state, -1));
+			lua_pop (cfg->lua_state, 1);
+
+			return FALSE;
+		}
+	}
+
 	/* Validate cache */
 	if (validate_cache) {
 		return rspamd_symbols_cache_validate (cfg->cache, cfg, FALSE);
diff --git a/src/lua/lua_config.c b/src/lua/lua_config.c
index 6e96c900c..cbf68dd07 100644
--- a/src/lua/lua_config.c
+++ b/src/lua/lua_config.c
@@ -393,9 +393,17 @@ LUA_FUNCTION_DEF (config, replace_regexp);
  * of script function depends on worker type
  * @param {string} worker_type worker type (e.g. "normal")
  * @param {function} script script for a worker
+ * @return {boolean} `true` if a script has been registered
  */
 LUA_FUNCTION_DEF (config, register_worker_script);
 
+/***
+ * @method rspamd_config:add_on_load(function(cfg) ... end)
+ * Registers the following script to be executed when configuration is completely loaded
+ * @param {function} script function to be executed
+ */
+LUA_FUNCTION_DEF (config, add_on_load);
+
 static const struct luaL_reg configlib_m[] = {
 	LUA_INTERFACE_DEF (config, get_module_opt),
 	LUA_INTERFACE_DEF (config, get_mempool),
@@ -424,6 +432,7 @@ static const struct luaL_reg configlib_m[] = {
 	LUA_INTERFACE_DEF (config, register_regexp),
 	LUA_INTERFACE_DEF (config, replace_regexp),
 	LUA_INTERFACE_DEF (config, register_worker_script),
+	LUA_INTERFACE_DEF (config, add_on_load),
 	{"__tostring", rspamd_lua_class_tostring},
 	{"__newindex", lua_config_newindex},
 	{NULL, NULL}
@@ -1675,6 +1684,24 @@ lua_config_register_worker_script (lua_State *L)
 	return 1;
 }
 
+static gint
+lua_config_add_on_load (lua_State *L)
+{
+	struct rspamd_config *cfg = lua_check_config (L, 1);
+	struct rspamd_config_post_load_script *sc;
+
+	if (cfg == NULL || lua_type (L, 2) != LUA_TFUNCTION) {
+		return luaL_error (L, "invalid arguments");
+	}
+
+	sc = rspamd_mempool_alloc0 (cfg->cfg_pool, sizeof (*sc));
+	lua_pushvalue (L, 2);
+	sc->cbref = luaL_ref (L, LUA_REGISTRYINDEX);
+	DL_APPEND (cfg->on_load, sc);
+
+	return 0;
+}
+
 void
 luaopen_config (lua_State * L)
 {
-- 
2.39.5