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|
package dhcpv6
import (
"fmt"
)
type DHCPv6 interface {
Type() MessageType
ToBytes() []byte
Summary() string
Length() int
}
func FromBytes(data []byte) (DHCPv6, error) {
var (
isRelay = false
headerSize int
messageType = MessageType(data[0])
)
if messageType == RELAY_FORW || messageType == RELAY_REPL {
isRelay = true
}
if isRelay {
headerSize = RelayHeaderSize
} else {
headerSize = MessageHeaderSize
}
if len(data) < headerSize {
return nil, fmt.Errorf("Invalid header size: shorter than %v bytes", headerSize)
}
if isRelay {
var (
linkAddr, peerAddr []byte
)
d := DHCPv6Relay{
messageType: messageType,
hopCount: uint8(data[1]),
}
linkAddr = append(linkAddr, data[2:18]...)
d.linkAddr = linkAddr
peerAddr = append(peerAddr, data[18:34]...)
d.peerAddr = peerAddr
options, err := OptionsFromBytes(data[34:])
if err != nil {
return nil, err
}
// TODO fail if no OptRelayMessage is present
d.options = options
return &d, nil
} else {
tid, err := BytesToTransactionID(data[1:4])
if err != nil {
return nil, err
}
d := DHCPv6Message{
messageType: messageType,
transactionID: *tid,
}
options, err := OptionsFromBytes(data[4:])
if err != nil {
return nil, err
}
d.options = options
return &d, nil
}
}
func NewMessage() (*DHCPv6Message, error) {
tid, err := GenerateTransactionID()
if err != nil {
return nil, err
}
d := DHCPv6Message{
messageType: SOLICIT,
transactionID: *tid,
}
return &d, nil
}
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