Add more specific dhcpv4 options (#17)

Added several DHCPv4 options

1 files changed, 57 insertions, 0 deletions

diff --git a/dhcpv4/option_requested_ip_address.go b/dhcpv4/option_requested_ip_address.go
new file mode 100644
index 0000000..8662263
--- /dev/null
+++ b/dhcpv4/option_requested_ip_address.go
@@ -0,0 +1,57 @@
+package dhcpv4
+
+import (
+	"fmt"
+	"net"
+)
+
+// This option implements the requested IP address option
+// https://tools.ietf.org/html/rfc2132
+
+// OptRequestedIPAddress represents an option encapsulating the server
+// identifier.
+type OptRequestedIPAddress struct {
+	RequestedAddr net.IP
+}
+
+// ParseOptRequestedIPAddress returns a new OptServerIdentifier from a byte
+// stream, or error if any.
+func ParseOptRequestedIPAddress(data []byte) (*OptRequestedIPAddress, error) {
+	if len(data) < 2 {
+		return nil, ErrShortByteStream
+	}
+	code := OptionCode(data[0])
+	if code != OptionRequestedIPAddress {
+		return nil, fmt.Errorf("expected code %v, got %v", OptionRequestedIPAddress, code)
+	}
+	length := int(data[1])
+	if length != 4 {
+		return nil, fmt.Errorf("unexepcted length: expected 4, got %v", length)
+	}
+	if len(data) < 6 {
+		return nil, ErrShortByteStream
+	}
+	return &OptRequestedIPAddress{RequestedAddr: net.IP(data[2 : 2+length])}, nil
+}
+
+// Code returns the option code.
+func (o *OptRequestedIPAddress) Code() OptionCode {
+	return OptionRequestedIPAddress
+}
+
+// ToBytes returns a serialized stream of bytes for this option.
+func (o *OptRequestedIPAddress) ToBytes() []byte {
+	ret := []byte{byte(o.Code()), byte(o.Length())}
+	return append(ret, o.RequestedAddr.To4()...)
+}
+
+// String returns a human-readable string.
+func (o *OptRequestedIPAddress) String() string {
+	return fmt.Sprintf("Requested IP Address -> %v", o.RequestedAddr.String())
+}
+
+// Length returns the length of the data portion (excluding option code an byte
+// length).
+func (o *OptRequestedIPAddress) Length() int {
+	return len(o.RequestedAddr.To4())
+}