all: upd chlog

CHANGELOG.md

@@ -25,9 +25,11 @@ NOTE: Add new changes BELOW THIS COMMENT.
 
 ### Added
 
+- Ability to edit static leases on *DHCP settings* page ([#1700]).
 - Ability to specify for how long clients should cache a filtered response,
   using the *Blocked response TTL* field on the *DNS settings* page ([#4569]).
 
+[#1700]: https://github.com/AdguardTeam/AdGuardHome/issues/1700
 [#4569]: https://github.com/AdguardTeam/AdGuardHome/issues/4569
 
 ### Fixed

internal/dhcpd/http_unix_internal_test.go

@@ -242,3 +242,78 @@ func TestServer_HandleUpdateStaticLease(t *testing.T) {
 		})
 	}
 }
+
+func TestServer_HandleUpdateStaticLease_validation(t *testing.T) {
+	const (
+		leaseV4Name = "static-client-v4"
+		leaseV4MAC  = "44:44:44:44:44:44"
+
+		anotherV4Name = "another-client-v4"
+		anotherV4MAC  = "55:55:55:55:55:55"
+	)
+
+	leaseV4IP := netip.MustParseAddr("192.168.10.10")
+	anotherV4IP := netip.MustParseAddr("192.168.10.20")
+
+	leases := []*leaseStatic{{
+		HWAddr:   leaseV4MAC,
+		IP:       leaseV4IP,
+		Hostname: leaseV4Name,
+	}, {
+		HWAddr:   anotherV4MAC,
+		IP:       anotherV4IP,
+		Hostname: anotherV4Name,
+	}}
+
+	s, err := Create(&ServerConfig{
+		Enabled:        true,
+		Conf4:          *defaultV4ServerConf(),
+		Conf6:          V6ServerConf{},
+		DataDir:        t.TempDir(),
+		ConfigModified: func() {},
+	})
+	require.NoError(t, err)
+
+	for _, l := range leases {
+		w := handleLease(t, l, s.handleDHCPAddStaticLease)
+		assert.Equal(t, http.StatusOK, w.Code)
+	}
+
+	testCases := []struct {
+		lease *leaseStatic
+		name  string
+		want  string
+	}{{
+		name: "v4_unknown_mac",
+		lease: &leaseStatic{
+			HWAddr:   "aa:aa:aa:aa:aa:aa",
+			IP:       leaseV4IP,
+			Hostname: leaseV4Name,
+		},
+		want: "dhcpv4: updating static lease: can't find lease aa:aa:aa:aa:aa:aa\n",
+	}, {
+		name: "update_v4_same_ip",
+		lease: &leaseStatic{
+			HWAddr:   leaseV4MAC,
+			IP:       anotherV4IP,
+			Hostname: leaseV4Name,
+		},
+		want: "dhcpv4: updating static lease: ip address is not unique\n",
+	}, {
+		name: "update_v4_same_name",
+		lease: &leaseStatic{
+			HWAddr:   leaseV4MAC,
+			IP:       leaseV4IP,
+			Hostname: anotherV4Name,
+		},
+		want: "dhcpv4: updating static lease: hostname is not unique\n",
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			w := handleLease(t, tc.lease, s.handleDHCPUpdateStaticLease)
+			assert.Equal(t, http.StatusBadRequest, w.Code)
+			assert.Equal(t, tc.want, w.Body.String())
+		})
+	}
+}

internal/dhcpd/v4_unix.go

@@ -309,9 +309,15 @@ func (s *v4Server) rmDynamicLease(lease *Lease) (err error) {
 	return nil
 }
 
-// ErrDupHostname is returned by addLease when the added lease has a not empty
-// non-unique hostname.
-const ErrDupHostname = errors.Error("hostname is not unique")
+const (
+	// ErrDupHostname is returned by addLease, validateStaticLease when the
+	// modified lease has a not empty non-unique hostname.
+	ErrDupHostname = errors.Error("hostname is not unique")
+
+	// ErrDupIP is returned by addLease, validateStaticLease when the modified
+	// lease has a non-unique IP address.
+	ErrDupIP = errors.Error("ip address is not unique")
+)
 
 // addLease adds a dynamic or static lease.
 func (s *v4Server) addLease(l *Lease) (err error) {
@@ -485,6 +491,11 @@ func (s *v4Server) validateStaticLease(l *Lease) (err error) {
 		return ErrDupHostname
 	}
 
+	dup, ok = s.ipIndex[l.IP]
+	if ok && !bytes.Equal(dup.HWAddr, l.HWAddr) {
+		return ErrDupIP
+	}
+
 	l.Hostname = hostname
 
 	if gwIP := s.conf.GatewayIP; gwIP == l.IP {