diff options
| -rw-r--r-- | dhcpv4/bsdp/bsdp.go | 2 | ||||
| -rw-r--r-- | dhcpv4/dhcpv4.go | 37 | ||||
| -rw-r--r-- | dhcpv4/dhcpv4_test.go | 30 |
3 files changed, 60 insertions, 9 deletions
diff --git a/dhcpv4/bsdp/bsdp.go b/dhcpv4/bsdp/bsdp.go index 51ec20c..27de68e 100644 --- a/dhcpv4/bsdp/bsdp.go +++ b/dhcpv4/bsdp/bsdp.go @@ -73,7 +73,6 @@ func NewInformListForInterface(iface string, replyPort uint16) (*dhcpv4.DHCPv4, return nil, err } d.AddOption(&dhcpv4.OptClassIdentifier{Identifier: vendorClassID}) - d.AddOption(&dhcpv4.OptionGeneric{OptionCode: dhcpv4.OptionEnd}) return d, nil } @@ -138,6 +137,5 @@ func InformSelectForAck(ack dhcpv4.DHCPv4, replyPort uint16, selectedImage BootI }) d.AddOption(&dhcpv4.OptMessageType{MessageType: dhcpv4.MessageTypeInform}) d.AddOption(&OptVendorSpecificInformation{vendorOpts}) - d.AddOption(&dhcpv4.OptionGeneric{OptionCode: dhcpv4.OptionEnd}) return d, nil } diff --git a/dhcpv4/dhcpv4.go b/dhcpv4/dhcpv4.go index a88be19..2d73003 100644 --- a/dhcpv4/dhcpv4.go +++ b/dhcpv4/dhcpv4.go @@ -112,6 +112,8 @@ func New() (*DHCPv4, error) { return nil, err } d.options = options + // the End option has to be added explicitly + d.AddOption(&OptionGeneric{OptionCode: OptionEnd}) return &d, nil } @@ -142,14 +144,12 @@ func NewDiscoveryForInterface(ifname string) (*DHCPv4, error) { OptionDomainNameServer, }, }) - // the End option has to be added explicitly - d.AddOption(&OptionGeneric{OptionCode: OptionEnd}) return d, nil } // NewInformForInterface builds a new DHCPv4 Informational message with default // Ethernet HW type and the hardware address obtained from the specified -// interface. It does NOT put a DHCP End option at the end. +// interface. func NewInformForInterface(ifname string, needsBroadcast bool) (*DHCPv4, error) { d, err := New() if err != nil { @@ -214,11 +214,26 @@ func RequestFromOffer(offer DHCPv4) (*DHCPv4, error) { d.AddOption(&OptMessageType{MessageType: MessageTypeRequest}) d.AddOption(&OptRequestedIPAddress{RequestedAddr: offer.YourIPAddr()}) d.AddOption(&OptServerIdentifier{ServerID: serverIP}) - // the End option has to be added explicitly - d.AddOption(&OptionGeneric{OptionCode: OptionEnd}) return d, nil } +// NewReplyFromRequest builds a DHCPv4 reply from a request. +func NewReplyFromRequest(request *DHCPv4) (*DHCPv4, error) { + reply, err := New() + if err != nil { + return nil, err + } + reply.SetOpcode(OpcodeBootReply) + reply.SetHwType(request.HwType()) + reply.SetHwAddrLen(request.HwAddrLen()) + hwaddr := request.ClientHwAddr() + reply.SetClientHwAddr(hwaddr[:]) + reply.SetTransactionID(request.TransactionID()) + reply.SetFlags(request.Flags()) + reply.SetGatewayIPAddr(request.GatewayIPAddr()) + return reply, nil +} + // FromBytes encodes the DHCPv4 packet into a sequence of bytes, and returns an // error if the packet is not valid. func FromBytes(data []byte) (*DHCPv4, error) { @@ -556,9 +571,17 @@ func (d *DHCPv4) SetOptions(options []Option) { d.options = options } -// AddOption appends an option to the existing ones. +// AddOption appends an option to the existing ones. If the last option is an +// OptionEnd, it will be inserted before that. It does not deal with End +// options that appead before the end, like in malformed packets. func (d *DHCPv4) AddOption(option Option) { - d.options = append(d.options, option) + if len(d.options) == 0 || d.options[len(d.options)-1].Code() != OptionEnd { + d.options = append(d.options, option) + } else { + end := d.options[len(d.options)-1] + d.options[len(d.options)-1] = option + d.options = append(d.options, end) + } } // MessageType returns the message type, trying to extract it from the diff --git a/dhcpv4/dhcpv4_test.go b/dhcpv4/dhcpv4_test.go index 9d44810..55e082d 100644 --- a/dhcpv4/dhcpv4_test.go +++ b/dhcpv4/dhcpv4_test.go @@ -290,6 +290,8 @@ func TestNewToBytes(t *testing.T) { } // Magic Cookie expected = append(expected, MagicCookie...) + // End + expected = append(expected, 0xff) d, err := New() require.NoError(t, err) @@ -322,6 +324,24 @@ func TestGetOption(t *testing.T) { require.Equal(t, d.GetOneOption(OptionRouter), nil) } +func TestAddOption(t *testing.T) { + d, err := New() + if err != nil { + t.Fatal(err) + } + + hostnameOpt := &OptionGeneric{OptionCode: OptionHostName, Data: []byte("darkstar")} + bootFileOpt1 := &OptionGeneric{OptionCode: OptionBootfileName, Data: []byte("boot.img")} + bootFileOpt2 := &OptionGeneric{OptionCode: OptionBootfileName, Data: []byte("boot2.img")} + d.AddOption(hostnameOpt) + d.AddOption(bootFileOpt1) + d.AddOption(bootFileOpt2) + + options := d.Options() + require.Equal(t, len(options), 4) + require.Equal(t, options[3].Code(), OptionEnd) +} + func TestDHCPv4RequestFromOffer(t *testing.T) { offer, err := New() require.NoError(t, err) @@ -333,6 +353,16 @@ func TestDHCPv4RequestFromOffer(t *testing.T) { require.Equal(t, MessageTypeRequest, *req.MessageType()) } +func TestNewReplyFromRequest(t *testing.T) { + discover, err := New() + require.NoError(t, err) + discover.SetGatewayIPAddr(net.IPv4(192, 168, 0, 1)) + reply, err := NewReplyFromRequest(discover) + require.NoError(t, err) + require.Equal(t, discover.TransactionID(), reply.TransactionID()) + require.Equal(t, discover.GatewayIPAddr(), reply.GatewayIPAddr()) +} + func TestDHCPv4MessageTypeNil(t *testing.T) { m, err := New() require.NoError(t, err) |