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package dhcpv4
import (
"fmt"
"github.com/u-root/u-root/pkg/uio"
)
// Uint16 implements encoding and decoding functions for a uint16 as used in
// RFC 2132, Section 9.10.
type Uint16 uint16
// ToBytes returns a serialized stream of bytes for this option.
func (o Uint16) ToBytes() []byte {
buf := uio.NewBigEndianBuffer(nil)
buf.Write16(uint16(o))
return buf.Data()
}
// String returns a human-readable string for this option.
func (o Uint16) String() string {
return fmt.Sprintf("%d", uint16(o))
}
// FromBytes decodes data into o as per RFC 2132, Section 9.10.
func (o *Uint16) FromBytes(data []byte) error {
buf := uio.NewBigEndianBuffer(data)
*o = Uint16(buf.Read16())
return buf.FinError()
}
// GetUint16 parses a uint16 from code in o.
func GetUint16(code OptionCode, o Options) (uint16, error) {
v := o.Get(code)
if v == nil {
return 0, fmt.Errorf("option not present")
}
var u Uint16
if err := u.FromBytes(v); err != nil {
return 0, err
}
return uint16(u), nil
}
// OptMaxMessageSize returns a new DHCP Maximum Message Size option.
//
// The Maximum DHCP Message Size option is described by RFC 2132, Section 9.10.
func OptMaxMessageSize(size uint16) Option {
return Option{Code: OptionMaximumDHCPMessageSize, Value: Uint16(size)}
}
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