* Implement ability to add conditional rules to rspamd.xml

CMakeLists.txt

@@ -354,6 +354,7 @@ CHECK_INCLUDE_FILES(sys/wait.h  HAVE_SYS_WAIT_H)
 CHECK_INCLUDE_FILES(sys/param.h  HAVE_SYS_PARAM_H)
 CHECK_INCLUDE_FILES(sys/cdefs.h  HAVE_SYS_CDEFS_H)
 CHECK_INCLUDE_FILES(sys/file.h  HAVE_SYS_FILE_H)
+CHECK_INCLUDE_FILES(sys/utsname.h  HAVE_SYS_UTSNAME_H)
 CHECK_INCLUDE_FILES(sys/resource.h  HAVE_SYS_RESOURCE_H)
 CHECK_INCLUDE_FILES(netinet/in.h  HAVE_NETINET_IN_H)
 CHECK_INCLUDE_FILES(arpa/inet.h  HAVE_ARPA_INET_H)

config.h.in

@@ -67,7 +67,8 @@
 #cmakedefine HAVE_SYS_PARAM_H    1
 #cmakedefine HAVE_SYS_FILE_H     1
 #cmakedefine HAVE_SYS_RESOURCE_H 1
-#cmakedefine HAVE_SYS_TIMEB_H   1
+#cmakedefine HAVE_SYS_TIMEB_H    1
+#cmakedefine HAVE_SYS_UTSNAME_H  1
 
 #cmakedefine HAVE_PIDFILE        1
 

src/cfg_utils.c

@@ -930,10 +930,16 @@ read_xml_config (struct config_file *cfg, const gchar *filename)
 	/* Prepare xml parser */
 	ud.cfg = cfg;
 	ud.state = XML_READ_START;
+	ud.if_stack = g_queue_new ();
 
 	ctx = g_markup_parse_context_new (&xml_parser, G_MARKUP_TREAT_CDATA_AS_TEXT | G_MARKUP_PREFIX_ERROR_POSITION, &ud, NULL);
 	res = g_markup_parse_context_parse (ctx, data, st.st_size, &err);
 
+	if (g_queue_get_length (ud.if_stack) != 0) {
+		msg_err ("unexpected nesting for if arguments");
+		res = FALSE;
+	}
+
 	munmap (data, st.st_size);
 
 	return res;

src/cfg_xml.c

@@ -449,6 +449,42 @@ xml_error_quark (void)
 	return g_quark_from_static_string ("xml-error-quark");
 }
 
+static inline const gchar *
+xml_state_to_string (struct rspamd_xml_userdata *ud)
+{
+	switch (ud->state) {
+		case XML_READ_START:
+			return "read start tag";
+		case XML_READ_PARAM:
+			return "read param";
+		case XML_READ_MODULE:
+			return "read module section";
+		case XML_READ_MODULES:
+			return "read modules section";
+		case XML_READ_CLASSIFIER:
+			return "read classifier section";
+		case XML_READ_STATFILE:
+			return "read statfile section";
+		case XML_READ_METRIC:
+			return "read metric section";
+		case XML_READ_WORKER:
+			return "read worker section";
+		case XML_READ_VIEW:
+			return "read view section";
+		case XML_READ_LOGGING:
+			return "read logging section";
+		case XML_READ_VALUE:
+			return "read value";
+		case XML_SKIP_ELEMENTS:
+			return "skip if block";
+		case XML_ERROR:
+			return "error occured";
+		case XML_END:
+			return "read final tag";
+	}
+	/* Unreached */
+	return "unknown state";
+}
 
 static inline gboolean
 extract_attr (const gchar *attr, const gchar **attribute_names, const gchar **attribute_values, gchar **res) 
@@ -1333,8 +1369,23 @@ rspamd_xml_start_element (GMarkupParseContext *context, const gchar *element_nam
 {
 	struct rspamd_xml_userdata *ud = user_data;
 	struct classifier_config   *ccf;
-	gchar                      *res;
-
+	gchar                      *res, *condition;
+
+	if (g_ascii_strcasecmp (element_name, "if") == 0) {
+		/* Push current state to queue */
+		g_queue_push_head (ud->if_stack, GSIZE_TO_POINTER ((gsize)ud->state));
+		/* Now get attributes */
+		ud->cur_attrs = process_attrs (ud->cfg, attribute_names, attribute_values);
+		if ((condition = g_hash_table_lookup (ud->cur_attrs, "condition")) == NULL) {
+			msg_err ("unknown condition attribute for if tag");
+			*error = g_error_new (xml_error_quark (), XML_PARAM_MISSING, "param 'condition' is required for tag 'if'");
+			ud->state = XML_ERROR;
+		}
+		if (! lua_check_condition (ud->cfg, condition)) {
+			ud->state = XML_SKIP_ELEMENTS;
+		}
+		return;
+	}
 	switch (ud->state) {
 		case XML_READ_START:
 			if (g_ascii_strcasecmp (element_name, "rspamd") != 0) {
@@ -1432,6 +1483,9 @@ rspamd_xml_start_element (GMarkupParseContext *context, const gchar *element_nam
 				ud->cur_attrs = process_attrs (ud->cfg, attribute_names, attribute_values);
 			}
 			break;
+		case XML_SKIP_ELEMENTS:
+			/* Do nothing */
+			return;
 		case XML_READ_MODULE:
 		case XML_READ_METRIC:
 		case XML_READ_MODULES:
@@ -1444,7 +1498,10 @@ rspamd_xml_start_element (GMarkupParseContext *context, const gchar *element_nam
 			ud->cur_attrs = process_attrs (ud->cfg, attribute_names, attribute_values);
 			break;
 		default:
-			*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "element %s is unexpected in this state", element_name);
+			if (*error == NULL) {
+				*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "element %s is unexpected in this state %s",
+					element_name, xml_state_to_string (ud));
+			}
 			break;
 	}
 }
@@ -1471,8 +1528,25 @@ rspamd_xml_end_element (GMarkupParseContext	*context, const gchar *element_name,
 	struct metric              *m;
 	struct classifier_config   *ccf;
 	struct statfile            *st;
-	gboolean res;
+	gboolean                    res;
+	gpointer                    tptr;
 	
+	if (g_ascii_strcasecmp (element_name, "if") == 0) {
+		tptr = g_queue_pop_head (ud->if_stack);
+
+		if (tptr == NULL) {
+			*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "element %s is umatched", element_name);
+			ud->state = XML_ERROR;
+		}
+		/* Restore state */
+		if (ud->state == XML_SKIP_ELEMENTS) {
+			ud->state = GPOINTER_TO_SIZE (tptr);
+		}
+		/* Skip processing */
+
+		return;
+	}
+
 	switch (ud->state) {
 		case XML_READ_MODULE:
 			CHECK_TAG ("module", FALSE);
@@ -1562,6 +1636,8 @@ rspamd_xml_end_element (GMarkupParseContext	*context, const gchar *element_name,
 				ud->state = XML_ERROR;
 			}
 			break;
+		case XML_SKIP_ELEMENTS:
+			return;
 		default:
 			ud->state = XML_ERROR;
 			break;
@@ -1643,6 +1719,9 @@ rspamd_xml_text (GMarkupParseContext *context, const gchar *text, gsize text_len
 				ud->state = XML_ERROR;
 			}
 			break;
+		case XML_SKIP_ELEMENTS:
+			/* Do nothing */
+			return;
 		default:
 			ud->state = XML_ERROR;
 			break;
@@ -1650,41 +1729,6 @@ rspamd_xml_text (GMarkupParseContext *context, const gchar *text, gsize text_len
 
 }
 
-static inline const gchar *
-xml_state_to_string (struct rspamd_xml_userdata *ud)
-{
-	switch (ud->state) {
-		case XML_READ_START:
-			return "read start tag";
-		case XML_READ_PARAM:
-			return "read param";
-		case XML_READ_MODULE:
-			return "read module section";
-		case XML_READ_MODULES:
-			return "read modules section";
-		case XML_READ_CLASSIFIER:
-			return "read classifier section";
-		case XML_READ_STATFILE:
-			return "read statfile section";
-		case XML_READ_METRIC:
-			return "read metric section";
-		case XML_READ_WORKER:
-			return "read worker section";
-		case XML_READ_VIEW:
-			return "read view section";
-		case XML_READ_LOGGING:
-			return "read logging section";
-		case XML_READ_VALUE:
-			return "read value";
-		case XML_ERROR:
-			return "error occured";
-		case XML_END:
-			return "read final tag";
-	}
-	/* Unreached */
-	return "unknown state";
-}
-
 void 
 rspamd_xml_error (GMarkupParseContext *context, GError *error, gpointer user_data)
 {

src/cfg_xml.h

@@ -24,6 +24,7 @@ enum xml_read_state {
 	XML_READ_VIEW,
 	XML_READ_LOGGING,
 	XML_READ_VALUE,
+	XML_SKIP_ELEMENTS,
 	XML_ERROR,
 	XML_END
 };
@@ -39,13 +40,17 @@ enum module_opt_type {
 	MODULE_OPT_TYPE_ANY
 };
 
+/**
+ * Structure that is used for semantic resolution of configuration
+ */
 struct rspamd_xml_userdata {
-	enum xml_read_state state;
-	struct config_file *cfg;
-	gchar section_name[MAX_NAME];
-	gpointer section_pointer;
-	gpointer parent_pointer;
-	GHashTable *cur_attrs;
+	enum xml_read_state state;				/*< state of parser							*/
+	struct config_file *cfg;				/*< configuration object 					*/
+	gchar section_name[MAX_NAME];			/*< current section							*/
+	gpointer section_pointer;				/*< pointer to object related with section	*/
+	gpointer parent_pointer;				/*< parent's section object					*/
+	GHashTable *cur_attrs;					/*< attributes of current tag				*/
+	GQueue *if_stack;						/*< stack of if elements					*/
 };
 
 /* Text is NULL terminated here */

src/lua/lua_cfg_file.c

@@ -23,6 +23,9 @@
  */
 
 #include "lua_common.h"
+#ifdef HAVE_SYS_UTSNAME_H
+#include <sys/utsname.h>
+#endif
 
 /* 
  * This is implementation of lua routines to handle config file params 
@@ -295,3 +298,66 @@ lua_handle_param (struct worker_task *task, gchar *mname, gchar *optname, enum l
 	*res = NULL;
 	return FALSE;
 }
+
+#define FAKE_RES_VAR "rspamd_res"
+gboolean
+lua_check_condition (struct config_file *cfg, const gchar *condition)
+{
+	lua_State                            *L = cfg->lua_state;
+	gchar                                *hostbuf, *condbuf;
+	gsize                                 hostlen;
+	gboolean                              res;
+#ifdef HAVE_SYS_UTSNAME_H
+	struct utsname                        uts;
+#endif
+
+	/* Set some globals for condition */
+	/* XXX: think what other variables can be useful */
+	hostlen = sysconf (_SC_HOST_NAME_MAX) + 1;
+	hostbuf = alloca (hostlen);
+	gethostname (hostbuf, hostlen);
+	hostbuf[hostlen - 1] = '\0';
+
+	/* Hostname */
+	lua_pushstring (L, hostbuf);
+	lua_setglobal (L, "hostname");
+	/* Config file name */
+	lua_pushstring (L, cfg->cfg_name);
+	lua_setglobal (L, "cfg_name");
+	/* Check for uname */
+#ifdef HAVE_SYS_UTSNAME_H
+	uname (&uts);
+	lua_pushstring (L, uts.sysname);
+	lua_setglobal (L, "osname");
+	lua_pushstring (L, uts.release);
+	lua_setglobal (L, "osrelease");
+#else
+	lua_pushstring (L, "unknown");
+	lua_setglobal (L, "osname");
+	lua_pushstring (L, "");
+	lua_setglobal (L, "osrelease");
+#endif
+	/* Make fake string */
+	hostlen = sizeof (FAKE_RES_VAR "=") + strlen (condition);
+	condbuf = g_malloc (hostlen);
+	rspamd_strlcpy (condbuf, FAKE_RES_VAR "=", sizeof (FAKE_RES_VAR "="));
+	g_strlcat (condbuf, condition, hostlen);
+	/* Evaluate condition */
+	if (luaL_dostring (L, condbuf) != 0) {
+		msg_err ("eval of '%s' failed: '%s'", condition, lua_tostring (L, -1));
+		g_free (condbuf);
+		return FALSE;
+	}
+	/* Get global variable res to get result */
+	lua_getglobal (L, FAKE_RES_VAR);
+	if (! lua_isboolean (L, -1)) {
+		msg_err ("bad string evaluated: %s, type: %s", condbuf, lua_typename (L, lua_type (L, -1)));
+		g_free (condbuf);
+			return FALSE;
+	}
+
+	res = lua_toboolean (L, -1);
+	g_free (condbuf);
+
+	return res;
+}

src/lua/lua_common.h

@@ -55,6 +55,7 @@ void lua_post_load_config (struct config_file *cfg);
 void lua_process_element (struct config_file *cfg, const gchar *name, struct module_opt *opt, gint idx);
 gboolean lua_handle_param (struct worker_task *task, gchar *mname, gchar *optname, 
 							enum lua_var_type expected_type, gpointer *res);
+gboolean lua_check_condition (struct config_file *cfg, const gchar *condition);
 
 
 #endif /* WITH_LUA */