/
lease.go
168 lines (154 loc) · 4.1 KB
/
lease.go
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package main
import (
"bytes"
"encoding/gob"
"net"
"github.com/hujun-open/etherconn"
"github.com/insomniacslk/dhcp/dhcpv4"
"github.com/insomniacslk/dhcp/dhcpv4/nclient4"
"github.com/insomniacslk/dhcp/dhcpv6"
"github.com/vishvananda/netlink"
)
//DHCPv4 lease
type v4Lease struct {
Lease *nclient4.Lease
VLANList etherconn.VLANs
IDOptions dhcpv4.Options
}
func newV4Lease() *v4Lease {
r := new(v4Lease)
r.VLANList = etherconn.VLANs{}
r.IDOptions = make(dhcpv4.Options)
return r
}
// addrStr returns a string as "ip/prefixlen"
func (lease *v4Lease) addrStr() string {
ipnet := net.IPNet{
IP: lease.Lease.ACK.YourIPAddr,
Mask: lease.Lease.ACK.SubnetMask(),
}
return ipnet.String()
}
// Apply replace/remove the lease on specified interface,
func (lease *v4Lease) Apply(ifname string, apply bool) error {
link, err := netlink.LinkByName(ifname)
if err != nil {
return err
}
addr, err := netlink.ParseAddr(lease.addrStr())
if err != nil {
return err
}
if apply {
return netlink.AddrReplace(link, addr)
}
return netlink.AddrDel(link, addr)
}
type v6Lease struct {
MAC net.HardwareAddr
ReplyOptions dhcpv6.Options
Type dhcpv6.MessageType //rely or solicit
VLANList etherconn.VLANs
IDOptions, RelayIDOptions dhcpv6.Options
}
type v6LeaseExport struct {
MAC net.HardwareAddr
ReplyOptionsBytes []byte
Type dhcpv6.MessageType //rely or solicit
VLANList etherconn.VLANs
IDOptionsBytes, RelayIDOptionsBytes []byte
}
func (lease v6Lease) MarshalBinary() ([]byte, error) {
export := v6LeaseExport{
MAC: lease.MAC,
ReplyOptionsBytes: lease.ReplyOptions.ToBytes(),
Type: lease.Type,
VLANList: lease.VLANList,
IDOptionsBytes: lease.IDOptions.ToBytes(),
RelayIDOptionsBytes: lease.RelayIDOptions.ToBytes(),
}
var buf bytes.Buffer
enc := gob.NewEncoder(&buf)
err := enc.Encode(&export)
return buf.Bytes(), err
}
func (lease *v6Lease) UnmarshalBinary(b []byte) error {
var export v6LeaseExport
buf := bytes.NewBuffer(b)
dec := gob.NewDecoder(buf)
err := dec.Decode(&export)
if err != nil {
return err
}
lease.MAC = export.MAC
lease.Type = export.Type
lease.VLANList = export.VLANList
err = (&lease.ReplyOptions).FromBytes(export.ReplyOptionsBytes)
if err != nil {
return err
}
err = (&lease.IDOptions).FromBytes(export.IDOptionsBytes)
if err != nil {
return err
}
err = (&lease.RelayIDOptions).FromBytes(export.RelayIDOptionsBytes)
if err != nil {
return err
}
return nil
}
// addStr return all IANA and IAPD as following format:
// NA: addr/128
// PD: prefix/len
func (lease *v6Lease) addrStr() (r []string) {
for _, na := range lease.ReplyOptions.Get(dhcpv6.OptionIANA) {
for _, addr := range na.(*dhcpv6.OptIANA).Options.Addresses() {
ipnet := net.IPNet{
IP: addr.IPv6Addr,
Mask: net.CIDRMask(128, 128),
}
r = append(r, ipnet.String())
}
}
for _, pd := range lease.ReplyOptions.Get(dhcpv6.OptionIAPD) {
for _, prefix := range pd.(*dhcpv6.OptIAPD).Options.Prefixes() {
r = append(r, prefix.Prefix.String())
}
}
return
}
func (lease *v6Lease) Genv6Release() (*dhcpv6.Message, error) {
msg, err := dhcpv6.NewMessage()
if err != nil {
return nil, err
}
msg.MessageType = dhcpv6.MessageTypeRelease
msg.AddOption(lease.ReplyOptions.GetOne(dhcpv6.OptionClientID))
msg.AddOption(lease.ReplyOptions.GetOne(dhcpv6.OptionServerID))
msg.AddOption(dhcpv6.OptElapsedTime(0))
for _, na := range lease.ReplyOptions.Get(dhcpv6.OptionIANA) {
msg.AddOption(na)
}
for _, pd := range lease.ReplyOptions.Get(dhcpv6.OptionIAPD) {
msg.AddOption(pd)
}
return msg, nil
}
func (lease *v6Lease) Apply(ifname string, apply bool) error {
link, err := netlink.LinkByName(ifname)
if err != nil {
return err
}
for _, addrstr := range lease.addrStr() {
addr, err := netlink.ParseAddr(addrstr)
if err != nil {
return err
}
if apply {
return netlink.AddrReplace(link, addr)
} else {
netlink.AddrDel(link, addr)
}
}
return nil
}