From ef789acee4ef990d9f93fa7f718f819b5bdea03d Mon Sep 17 00:00:00 2001
From: Simon Zolin <s.zolin@adguard.com>
Date: Tue, 19 Mar 2019 15:54:35 +0300
Subject: [PATCH] * control: DHCP: don't return expired leases

- fix potential race when lease's data can be modified while UI thread is reading it
---
 dhcpd/dhcpd.go | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/dhcpd/dhcpd.go b/dhcpd/dhcpd.go
index b54195a8..f1ce0f2a 100644
--- a/dhcpd/dhcpd.go
+++ b/dhcpd/dhcpd.go
@@ -517,10 +517,17 @@ func (s *Server) handleDecline(p dhcp4.Packet, options dhcp4.Options) dhcp4.Pack
 }
 
 // Leases returns the list of current DHCP leases (thread-safe)
-func (s *Server) Leases() []*Lease {
+func (s *Server) Leases() []Lease {
+	var result []Lease
+	now := time.Now().Unix()
 	s.RLock()
-	result := s.leases
+	for _, lease := range s.leases {
+		if lease.Expiry.Unix() > now {
+			result = append(result, *lease)
+		}
+	}
 	s.RUnlock()
+
 	return result
 }