set default rules directory if empty

Use /etc/opensnitchd/rules as the default directory if it has not been
provided via configuration.

daemon/main.go

@@ -580,6 +580,9 @@ func main() {
 		log.Fatal("%s", err)
 	}
 
+	if cfg.Rules.Path == "" {
+		cfg.Rules.Path = rule.DefaultPath
+	}
 	log.Info("Loading rules from %s ...", cfg.Rules.Path)
 	rules, err = rule.NewLoader(!noLiveReload)
 	if err != nil {

daemon/rule/loader.go

@@ -88,6 +88,9 @@ func (l *Loader) HasChecksums(op Operand) {
 // Reload loads rules from the specified path, deleting existing loaded
 // rules from memory.
 func (l *Loader) Reload(path string) error {
+	if path == "" {
+		path = DefaultPath
+	}
 	log.Info("rules.Loader.Reload(): %s", path)
 
 	// check that the new path exists before reloading

daemon/rule/rule.go

@@ -9,6 +9,11 @@ import (
 	"github.com/evilsocket/opensnitch/daemon/ui/protocol"
 )
 
+// DefaultPath directory
+const (
+	DefaultPath = "/etc/opensnitchd/rules"
+)
+
 // Action of a rule
 type Action string
 

daemon/ui/config_utils.go

@@ -166,7 +166,7 @@ func (c *Client) reloadConfiguration(reload bool, newConfig config.Config) *moni
 
 	// 1. load rules
 	c.rules.EnableChecksums(newConfig.Rules.EnableChecksums)
-	if c.config.Rules.Path != newConfig.Rules.Path {
+	if newConfig.Rules.Path == "" || c.config.Rules.Path != newConfig.Rules.Path {
 		c.rules.Reload(newConfig.Rules.Path)
 		log.Debug("[config] reloading config.rules.path, old: <%s> new: <%s>", c.config.Rules.Path, newConfig.Rules.Path)
 	} else {