cfgutils: proper check for return code looking up routing block in ro…

…ute_exists()

- when the route block doesn't exist, route_lookup() returns -1, which
  was used to access routing actions due to condition expecting 0 on not
  found. The fix should avoid crashing by accessing invalid addresses.
  Reported by Alex Balashov
- fixed return codes in the configuration file to follow the rules with
  positive being evaluated to true and negative to false
- route_exists() returns the code returned by running actions, like a
  classic sub-route execution

modules/cfgutils/cfgutils.c

@@ -97,8 +97,8 @@ static int dbg_pkg_status(struct sip_msg*, char*,char*);
 static int dbg_shm_status(struct sip_msg*, char*,char*);
 static int dbg_pkg_summary(struct sip_msg*, char*,char*);
 static int dbg_shm_summary(struct sip_msg*, char*,char*);
-static int route_exists(struct sip_msg*, char*);
-static int check_route_exists(struct sip_msg*, char*);
+static int w_route_exists(struct sip_msg*, char*);
+static int w_check_route_exists(struct sip_msg*, char*);
 
 static int set_gflag(struct sip_msg*, char *, char *);
 static int reset_gflag(struct sip_msg*, char *, char *);
@@ -186,9 +186,9 @@ static cmd_export_t cmds[]={
 		ANY_ROUTE},
 	{"core_hash",    (cmd_function)w_core_hash, 3,   fixup_core_hash, 0,
 		ANY_ROUTE},
-	{"check_route_exists",    (cmd_function)check_route_exists, 1,   0, 0,
+	{"check_route_exists",    (cmd_function)w_check_route_exists, 1,   0, 0,
 		ANY_ROUTE},
-	{"route_if_exists",    (cmd_function)route_exists, 1,   0, 0,
+	{"route_if_exists",    (cmd_function)w_route_exists, 1,   0, 0,
 		ANY_ROUTE},
 	{"bind_cfgutils", (cmd_function)bind_cfgutils,  0,
 		0, 0, 0},
@@ -873,29 +873,32 @@ static int w_cfg_unlock(struct sip_msg *msg, char *key, char *s2)
 
 /*! Check if a route block exists - only request routes
  */
-static int check_route_exists(struct sip_msg *msg, char *route)
+static int w_check_route_exists(struct sip_msg *msg, char *route)
 {
-	if (route_lookup(&main_rt, route))
-		return 1;
-	return 0;
+	if (route_lookup(&main_rt, route)<0) {
+		/* not found */
+		return -1;
+	}
+	return 1;
 }
 
 /*! Run a request route block if it exists
  */
-static int route_exists(struct sip_msg *msg, char *route)
+static int w_route_exists(struct sip_msg *msg, char *route)
 {
 	struct run_act_ctx ctx;
-	int newroute, backup_rt;
+	int newroute, backup_rt, ret;
 
-	if (!(newroute = route_lookup(&main_rt, route))) {
-		return 0;
+	newroute = route_lookup(&main_rt, route);
+	if (newroute<0) {
+		return -1;
 	}
 	backup_rt = get_route_type();
 	set_route_type(REQUEST_ROUTE);
 	init_run_actions_ctx(&ctx);
-	run_top_route(main_rt.rlist[newroute], msg, 0);
+	ret = run_top_route(main_rt.rlist[newroute], msg, &ctx);
 	set_route_type(backup_rt);
-	return 0;
+	return ret;
 }
 
 static int mod_init(void)