Merge pull request #108 from pmazzini/master

add OptIPAddressLeaseTime

5 files changed, 103 insertions, 3 deletions

diff --git a/dhcpv4/option_ip_address_lease_time.go b/dhcpv4/option_ip_address_lease_time.go
new file mode 100644
index 0000000..a171b04
--- /dev/null
+++ b/dhcpv4/option_ip_address_lease_time.go
@@ -0,0 +1,57 @@
+package dhcpv4
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+// This option implements the IP Address Lease Time option
+// https://tools.ietf.org/html/rfc2132
+
+// OptIPAddressLeaseTime represents the IP Address Lease Time option.
+type OptIPAddressLeaseTime struct {
+	LeaseTime uint32
+}
+
+// ParseOptIPAddressLeaseTime constructs an OptIPAddressLeaseTime struct from a
+// sequence of bytes and returns it, or an error.
+func ParseOptIPAddressLeaseTime(data []byte) (*OptIPAddressLeaseTime, error) {
+	// Should at least have code, length, and lease time.
+	if len(data) < 4 {
+		return nil, ErrShortByteStream
+	}
+	code := OptionCode(data[0])
+	if code != OptionIPAddressLeaseTime {
+		return nil, fmt.Errorf("expected option %v, got %v instead", OptionIPAddressLeaseTime, code)
+	}
+	length := int(data[1])
+	if length != 4 {
+		return nil, fmt.Errorf("expected length 4, got %v instead", length)
+	}
+	leaseTime := binary.BigEndian.Uint32(data[2:6])
+	return &OptIPAddressLeaseTime{LeaseTime: leaseTime}, nil
+}
+
+// Code returns the option code.
+func (o *OptIPAddressLeaseTime) Code() OptionCode {
+	return OptionIPAddressLeaseTime
+}
+
+// ToBytes returns a serialized stream of bytes for this option.
+func (o *OptIPAddressLeaseTime) ToBytes() []byte {
+	serializedTime := make([]byte, 4)
+	binary.BigEndian.PutUint32(serializedTime, o.LeaseTime)
+	serializedOpt := []byte{byte(o.Code()), byte(o.Length())}
+	return append(serializedOpt, serializedTime...)
+}
+
+// String returns a human-readable string for this option.
+func (o *OptIPAddressLeaseTime) String() string {
+	return fmt.Sprintf("IP Addresses Lease Time -> %v", o.LeaseTime)
+}
+
+// Length returns the length of the data portion (excluding option code and byte
+// for length, if any).
+func (o *OptIPAddressLeaseTime) Length() int {
+	return 4
+}
diff --git a/dhcpv4/option_ip_address_lease_time_test.go b/dhcpv4/option_ip_address_lease_time_test.go
new file mode 100644
index 0000000..66715bd
--- /dev/null
+++ b/dhcpv4/option_ip_address_lease_time_test.go
@@ -0,0 +1,41 @@
+package dhcpv4
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestOptIPAddressLeaseTimeInterfaceMethods(t *testing.T) {
+	o := OptIPAddressLeaseTime{LeaseTime: 43200}
+	require.Equal(t, OptionIPAddressLeaseTime, o.Code(), "Code")
+	require.Equal(t, 4, o.Length(), "Length")
+	require.Equal(t, []byte{51, 4, 0, 0, 168, 192}, o.ToBytes(), "ToBytes")
+}
+
+func TestParseOptIPAddressLeaseTime(t *testing.T) {
+	data := []byte{51, 4, 0, 0, 168, 192}
+	o, err := ParseOptIPAddressLeaseTime(data)
+	require.NoError(t, err)
+	require.Equal(t, &OptIPAddressLeaseTime{LeaseTime: 43200}, o)
+
+	// Short byte stream
+	data = []byte{51, 4}
+	_, err = ParseOptIPAddressLeaseTime(data)
+	require.Error(t, err, "should get error from short byte stream")
+
+	// Wrong code
+	data = []byte{54, 4, 0, 0, 168, 192}
+	_, err = ParseOptIPAddressLeaseTime(data)
+	require.Error(t, err, "should get error from wrong code")
+
+	// Bad length
+	data = []byte{51, 5, 1, 1, 1, 1, 1}
+	_, err = ParseOptIPAddressLeaseTime(data)
+	require.Error(t, err, "should get error from bad length")
+}
+
+func TestOptIPAddressLeaseTimeString(t *testing.T) {
+	o := OptIPAddressLeaseTime{LeaseTime: 43200}
+	require.Equal(t, "IP Addresses Lease Time -> 43200", o.String())
+}
diff --git a/dhcpv4/option_maximum_dhcp_message_size.go b/dhcpv4/option_maximum_dhcp_message_size.go
index 05186f5..e5fedc6 100644
--- a/dhcpv4/option_maximum_dhcp_message_size.go
+++ b/dhcpv4/option_maximum_dhcp_message_size.go
@@ -8,7 +8,7 @@ import (
 // This option implements the Maximum DHCP Message size option
 // https://tools.ietf.org/html/rfc2132
 
-// OptMaximumDHCPMessageSize represents the DHCP message type option.
+// OptMaximumDHCPMessageSize represents the Maximum DHCP Message size option.
 type OptMaximumDHCPMessageSize struct {
 	Size uint16
 }
@@ -16,7 +16,7 @@ type OptMaximumDHCPMessageSize struct {
 // ParseOptMaximumDHCPMessageSize constructs an OptMaximumDHCPMessageSize struct from a sequence of
 // bytes and returns it, or an error.
 func ParseOptMaximumDHCPMessageSize(data []byte) (*OptMaximumDHCPMessageSize, error) {
-	// Should at least have code, length, and message type.
+	// Should at least have code, length, and message size.
 	if len(data) < 4 {
 		return nil, ErrShortByteStream
 	}
diff --git a/dhcpv4/option_maximum_dhcp_message_size_test.go b/dhcpv4/option_maximum_dhcp_message_size_test.go
index 65a26fc..f24b499 100644
--- a/dhcpv4/option_maximum_dhcp_message_size_test.go
+++ b/dhcpv4/option_maximum_dhcp_message_size_test.go
@@ -14,7 +14,7 @@ func TestOptMaximumDHCPMessageSizeInterfaceMethods(t *testing.T) {
 }
 
 func TestParseOptMaximumDHCPMessageSize(t *testing.T) {
-	data := []byte{57, 2, 5, 220} // DISCOVER
+	data := []byte{57, 2, 5, 220}
 	o, err := ParseOptMaximumDHCPMessageSize(data)
 	require.NoError(t, err)
 	require.Equal(t, &OptMaximumDHCPMessageSize{Size: 1500}, o)
diff --git a/dhcpv4/options.go b/dhcpv4/options.go
index 4224fa0..760bc98 100644
--- a/dhcpv4/options.go
+++ b/dhcpv4/options.go
@@ -46,6 +46,8 @@ func ParseOption(data []byte) (Option, error) {
 		opt, err = ParseOptRouter(data)
 	case OptionRequestedIPAddress:
 		opt, err = ParseOptRequestedIPAddress(data)
+	case OptionIPAddressLeaseTime:
+		opt, err = ParseOptIPAddressLeaseTime(data)
 	case OptionDHCPMessageType:
 		opt, err = ParseOptMessageType(data)
 	case OptionParameterRequestList: