From 6bf512f96fbe5693473a580330ef954fc7457cd2 Mon Sep 17 00:00:00 2001
From: Andrey Meshkov <am@adguard.com>
Date: Mon, 23 Dec 2019 16:59:02 +0300
Subject: [PATCH] -(home): fix searching clients by mac address

---
 dhcpd/dhcpd.go       | 12 +++++++++--
 dhcpd/dhcpd_test.go  |  5 +++--
 home/clients_test.go | 50 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 63 insertions(+), 4 deletions(-)

diff --git a/dhcpd/dhcpd.go b/dhcpd/dhcpd.go
index 0fb38f24..06bb40ea 100644
--- a/dhcpd/dhcpd.go
+++ b/dhcpd/dhcpd.go
@@ -709,9 +709,17 @@ func (s *Server) FindMACbyIP(ip net.IP) net.HardwareAddr {
 	s.leasesLock.RLock()
 	defer s.leasesLock.RUnlock()
 
+	ip4 := ip.To4()
+	if ip4 == nil {
+		return nil
+	}
+
 	for _, l := range s.leases {
-		if l.Expiry.Unix() > now && l.IP.Equal(ip) {
-			return l.HWAddr
+		if l.IP.Equal(ip4) {
+			unix := l.Expiry.Unix()
+			if unix > now || unix == leaseExpireStatic {
+				return l.HWAddr
+			}
 		}
 	}
 	return nil
diff --git a/dhcpd/dhcpd_test.go b/dhcpd/dhcpd_test.go
index 00c17276..95522f3e 100644
--- a/dhcpd/dhcpd_test.go
+++ b/dhcpd/dhcpd_test.go
@@ -23,6 +23,7 @@ func check(t *testing.T, result bool, msg string) {
 func TestDHCP(t *testing.T) {
 	var s = Server{}
 	s.conf.DBFilePath = dbFilename
+	defer func() { _ = os.Remove(dbFilename) }()
 	var p, p2 dhcp4.Packet
 	var hw net.HardwareAddr
 	var lease *Lease
@@ -185,7 +186,7 @@ func TestDB(t *testing.T) {
 	lease, _ = s.reserveLease(p)
 	lease.Expiry = time.Unix(4000000002, 0)
 
-	os.Remove("leases.db")
+	_ = os.Remove("leases.db")
 	s.dbStore()
 	s.reset()
 
@@ -198,7 +199,7 @@ func TestDB(t *testing.T) {
 	check(t, bytes.Equal(s.leases[1].IP, []byte{1, 1, 1, 2}), "leases[1].IP")
 	check(t, s.leases[1].Expiry.Unix() == 4000000002, "leases[1].Expiry")
 
-	os.Remove("leases.db")
+	_ = os.Remove("leases.db")
 }
 
 func TestIsValidSubnetMask(t *testing.T) {
diff --git a/home/clients_test.go b/home/clients_test.go
index 2573d48f..8ba06a1c 100644
--- a/home/clients_test.go
+++ b/home/clients_test.go
@@ -1,7 +1,12 @@
 package home
 
 import (
+	"net"
+	"os"
 	"testing"
+	"time"
+
+	"github.com/AdguardTeam/AdGuardHome/dhcpd"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -172,3 +177,48 @@ func TestClientsWhois(t *testing.T) {
 	assert.True(t, clients.idIndex["1.1.1.2"].WhoisInfo[0][1] == "orgname-val")
 	_ = clients.Del("client1")
 }
+
+func TestClientsAddExistingHost(t *testing.T) {
+	var c Client
+	clients := clientsContainer{}
+	clients.testing = true
+	clients.Init(nil, nil)
+
+	// some test variables
+	mac, _ := net.ParseMAC("aa:aa:aa:aa:aa:aa")
+	testIP := "1.2.3.4"
+
+	// add a client
+	c = Client{
+		IDs:  []string{"1.1.1.1", "1:2:3::4", "aa:aa:aa:aa:aa:aa"},
+		Name: "client1",
+	}
+	ok, err := clients.Add(c)
+	assert.True(t, ok)
+	assert.Nil(t, err)
+
+	// try adding a duplicate by IP
+	ok, err = clients.AddHost("1.1.1.1", "test", ClientSourceRDNS)
+	assert.False(t, ok)
+	assert.Nil(t, err)
+
+	// now some more complicated stuff
+	// first, init a DHCP server with a single static lease
+	config := dhcpd.ServerConfig{
+		DBFilePath: "leases.db",
+	}
+	defer func() { _ = os.Remove("leases.db") }()
+	clients.dhcpServer = dhcpd.Create(config)
+	err = clients.dhcpServer.AddStaticLease(dhcpd.Lease{
+		HWAddr:   mac,
+		IP:       net.ParseIP(testIP).To4(),
+		Hostname: "testhost",
+		Expiry:   time.Now().Add(time.Hour),
+	})
+	assert.Nil(t, err)
+
+	// try adding a duplicate IP which for a Mac-based client
+	ok, err = clients.AddHost(testIP, "test", ClientSourceRDNS)
+	assert.False(t, ok)
+	assert.Nil(t, err)
+}