Fix sigsev when conLdap.Close() after connection was droped remotely

mynettcptable.go

@@ -26,7 +26,7 @@ import (
 )
 
 const (
-	version = "1.0.0-rc2"
+	version = "1.0.1"
 )
 
 var (
@@ -227,7 +227,12 @@ func handleConnection(connClt net.Conn, conLdap *ldap.Conn) {
 		// First query netCache built with ipNetworkNumber
 		res, err := isIPContainedInNetCache(ip)
 		if err != nil {
+			if strings.EqualFold(err.Error(), fmt.Sprintf("Invalid IP: %s", ip)) {
+				// We don't want those msg to pollute logs
+				logstream.Info(err.Error())
+			} else {
 				logstream.Error(err.Error())
+			}
 			sendResponse(connClt, err.Error(), 500)
 			continue
 		}
@@ -279,7 +284,11 @@ func searchLdap(searchReq *ldap.SearchRequest, attempt int) (*ldap.SearchResult,
 	if err != nil && strings.HasSuffix(err.Error(), "ldap: connection closed") {
 		logstream.Error("LDAP connection closed, retrying")
 		mutex.Lock()
+		// 16/01/2023: panic: runtime error: invalid memory address or nil pointer dereference
+		// probably bc connection is already closed
+		if conLdap != nil {
 			conLdap.Close()
+		}
 		conLdap, err = connectLdap()
 		mutex.Unlock()
 		if err != nil {
@@ -297,12 +306,12 @@ func connectLdap() (*ldap.Conn, error) {
 	conLdap, err = ldap.DialURL(*ldapURL)
 	if err != nil {
 		logstream.Errorf("Error dialing LDAP on %s: %v\n", *ldapURL, err)
-		return conLdap, err
+		return nil, err
 	}
 	err = conLdap.Bind(*ldapUser, *ldapPass)
 	if err != nil {
-		logstream.Errorf("Error binding LDAP: ", err)
-		return conLdap, err
+		logstream.Errorf("Error binding LDAP: %s", err)
+		return nil, err
 	}
 	return conLdap, err
 }
@@ -349,7 +358,7 @@ func main() {
 	ldapBaseDN = fs.String("ldapDN", "", "LDAP base DN (also via LDAPDN env var)")
 	ldapUser = fs.String("ldapUser", "", "LDAP user DN (also via LDAPUSER env var)")
 	ldapPass = fs.String("ldapPass", "", "LDAP user password (also via LDAPPASS env var)")
-	pidFilePath = fs.String("pidfile", "/var/run/mynettcptable/mynettcptable.pid", "PID File (also via PIDFILE env var)")
+	pidFilePath = fs.String("pidfile", "", "PID File (also via PIDFILE env var). Creates pidfile only if defined")
 	refreshInterval = fs.Int("refresh", 300, "Net cache update interval in seconds")
 	timeout = fs.Int("timeout", 5, "timeout in seconds")
 	_ = fs.String("config", "", "config file (optional)")
@@ -403,11 +412,13 @@ func main() {
 		logstream.Hooks.Add(hook)
 	}
 
+	if len(*pidFilePath) > 0 {
 		if pid, err := pidfile.Create(*pidFilePath); err != nil {
 			logstream.Fatal(err)
 		} else {
 			defer pid.Clear()
 		}
+	}
 
 	logstream.Infof("Start listening for incoming connections on %s\n", *listen)
 	run()