dhcp module update

This commit is contained in:
Nathan Gieseker
2019-06-26 01:25:22 -07:00
parent addbcd34b4
commit ce60e8eb3d
9 changed files with 123 additions and 52 deletions

View File

@ -11,7 +11,7 @@ type Option struct {
type Options map[OptionCode][]byte
// SelectOrderOrAll has same functionality as SelectOrder, except if the order
// param is nil, whereby all options are added (in arbitary order).
// param is nil, whereby all options are added (in arbitrary order).
func (o Options) SelectOrderOrAll(order []byte) []Option {
if order == nil {
opts := make([]Option, 0, len(o))

View File

@ -127,10 +127,11 @@ func ReplyPacket(req Packet, mt MessageType, serverId, yIAddr net.IP, leaseDurat
p.SetYIAddr(yIAddr)
p.SetGIAddr(req.GIAddr())
p.SetCHAddr(req.CHAddr())
p.SetSecs(req.Secs())
p.AddOption(OptionDHCPMessageType, []byte{byte(mt)})
p.AddOption(OptionServerIdentifier, []byte(serverId))
p.AddOption(OptionIPAddressLeaseTime, OptionsLeaseTime(leaseDuration))
if leaseDuration > 0 {
p.AddOption(OptionIPAddressLeaseTime, OptionsLeaseTime(leaseDuration))
}
for _, o := range options {
p.AddOption(o.Code, o.Value)
}

View File

@ -1,7 +1,10 @@
package leasepool
import (
"bytes"
"encoding/hex"
"encoding/json"
"fmt"
"net"
"time"
)
@ -18,37 +21,35 @@ type Lease struct {
IP net.IP //The IP of the Lease
Status LeaseStatus //Are Reserved, Active or Free
MACAddress net.HardwareAddr //Mac Address of the Device
ClientID []byte //ClientID of the request
Hostname string //Hostname From option 12
Expiry time.Time //Expiry Time
}
func (this Lease) MarshalJSON() ([]byte, error) {
stringMarshal := struct {
IP string
Status int
MACAddress string
Hostname string
Expiry time.Time
}{
(this.IP.String()),
int(this.Status),
(this.MACAddress.String()),
this.Hostname,
this.Expiry,
}
//leaseMarshal is a mirror of Lease used for marshalling, since
//net.HardwareAddr has no native marshalling capability.
type leaseMarshal struct {
IP string
Status int
MACAddress string
ClientID string
Hostname string
Expiry time.Time
}
return json.Marshal(stringMarshal)
func (this Lease) MarshalJSON() ([]byte, error) {
return json.Marshal(leaseMarshal{
IP: this.IP.String(),
Status: int(this.Status),
MACAddress: this.MACAddress.String(),
ClientID: hex.EncodeToString(this.ClientID),
Hostname: this.Hostname,
Expiry: this.Expiry,
})
}
func (this *Lease) UnmarshalJSON(data []byte) error {
stringUnMarshal := struct {
IP string
Status int
MACAddress string
Hostname string
Expiry time.Time
}{}
stringUnMarshal := leaseMarshal{}
err := json.Unmarshal(data, &stringUnMarshal)
if err != nil {
return err
@ -58,12 +59,14 @@ func (this *Lease) UnmarshalJSON(data []byte) error {
this.Status = LeaseStatus(stringUnMarshal.Status)
if stringUnMarshal.MACAddress != "" {
this.MACAddress, err = net.ParseMAC(stringUnMarshal.MACAddress)
if err != nil {
return fmt.Errorf("error parsing MAC address: %v", err)
}
}
this.ClientID, err = hex.DecodeString(stringUnMarshal.ClientID)
if err != nil {
return err
return fmt.Errorf("error decoding clientID: %v", err)
}
this.Hostname = stringUnMarshal.Hostname
this.Expiry = stringUnMarshal.Expiry
@ -83,6 +86,10 @@ func (this Lease) Equal(other Lease) bool {
return false
}
if !bytes.Equal(this.ClientID, other.ClientID) {
return false
}
if this.Hostname != other.Hostname {
return false
}

View File

@ -25,8 +25,8 @@ type LeasePool interface {
*/
GetLease(net.IP) (bool, Lease, error)
//Get the lease already in use by that hardware address.
GetLeaseForHardwareAddress(net.HardwareAddr) (bool, Lease, error)
//Get the lease already in use by that hardware address and/or client identifier.
GetLeaseForClient(net.HardwareAddr, []byte) (bool, Lease, error)
/*
* -Lease Available

View File

@ -81,13 +81,23 @@ func (t *MemoryPool) GetLease(leaseIP net.IP) (bool, leasepool.Lease, error) {
return false, leasepool.Lease{}, nil
}
//Get the lease already in use by that hardware address.
func (t *MemoryPool) GetLeaseForHardwareAddress(macAddress net.HardwareAddr) (bool, leasepool.Lease, error) {
func makeKey(macAddress net.HardwareAddr, clientID []byte) []byte {
key := []byte(macAddress)
if len(clientID) > 0 {
key = append(key, clientID...)
}
return key
}
//Get the lease already in use by that hardware address and/or client identifier.
func (t *MemoryPool) GetLeaseForClient(macAddress net.HardwareAddr, clientID []byte) (bool, leasepool.Lease, error) {
t.poolLock.Lock()
defer t.poolLock.Unlock()
needleKey := makeKey(macAddress, clientID)
for i := range t.pool {
if bytes.Equal(t.pool[i].MACAddress, macAddress) {
haystackKey := makeKey(t.pool[i].MACAddress, t.pool[i].ClientID)
if bytes.Equal(needleKey, haystackKey) {
return true, t.pool[i], nil
}
}
@ -139,6 +149,7 @@ func (t *MemoryPool) UpdateLease(lease leasepool.Lease) (bool, error) {
if t.pool[i].IP.Equal(lease.IP) {
t.pool[i].MACAddress = lease.MACAddress
t.pool[i].ClientID = lease.ClientID
t.pool[i].Hostname = lease.Hostname
t.pool[i].Expiry = lease.Expiry
t.pool[i].Status = lease.Status

View File

@ -172,9 +172,6 @@ func (s *Server) ListenAndServe() error {
// return err
//}
//Make Our Buffer (Max Buffer is 574) "I believe this 576 size comes from RFC 791" - Random Mailing list quote of the day.
buffer := make([]byte, 576)
log.Println("Trace: DHCP Server Listening.")
for {
@ -183,6 +180,9 @@ func (s *Server) ListenAndServe() error {
return nil
}
//Make Our Buffer (Max Buffer is 574) "I believe this 576 size comes from RFC 791" - Random Mailing list quote of the day.
buffer := make([]byte, 576)
//Set Read Deadline
s.connection.SetReadDeadline(time.Now().Add(time.Second))
// Read Packet
@ -213,7 +213,6 @@ func (s *Server) ListenAndServe() error {
}
log.Printf("Debug: Unexpect Error from Connection Read From: %v\n", err)
log.Printf("Debug: err type %T %#v\n", err, err)
return err
}
@ -281,6 +280,13 @@ func (s *Server) ListenAndServe() error {
}
}
func getClientID(packetOptions dhcp4.Options) []byte {
if clientID, ok := packetOptions[dhcp4.OptionClientIdentifier]; ok {
return clientID
}
return nil
}
func (s *Server) ServeDHCP(packet dhcp4.Packet) (dhcp4.Packet, error) {
packetOptions := packet.ParseOptions()
@ -307,6 +313,7 @@ func (s *Server) ServeDHCP(packet dhcp4.Packet) (dhcp4.Packet, error) {
lease.Status = leasepool.Reserved
lease.MACAddress = packet.CHAddr()
lease.ClientID = getClientID(packetOptions)
//If the lease expires within the next 5 Mins increase the lease expiary (Giving the Client 5 mins to complete)
if lease.Expiry.Before(time.Now().Add(time.Minute * 5)) {
@ -351,6 +358,7 @@ func (s *Server) ServeDHCP(packet dhcp4.Packet) (dhcp4.Packet, error) {
} else {
lease.Status = leasepool.Active
lease.MACAddress = packet.CHAddr()
lease.ClientID = getClientID(packetOptions)
lease.Expiry = time.Now().Add(s.leaseDuration)
@ -498,6 +506,8 @@ func (s *Server) DeclinePacket(requestPacket dhcp4.Packet) dhcp4.Packet {
func (s *Server) GetLease(packet dhcp4.Packet) (found bool, lease leasepool.Lease, err error) {
packetOptions := packet.ParseOptions()
clientID := getClientID(packetOptions)
//Requested an IP
if (len(packetOptions) > 0) &&
packetOptions[dhcp4.OptionRequestedIPAddress] != nil &&
@ -510,11 +520,15 @@ func (s *Server) GetLease(packet dhcp4.Packet) (found bool, lease leasepool.Leas
}
if found {
//If lease is free, return it to client. If it is not
//free match against the MAC address and client
//identifier.
if lease.Status == leasepool.Free {
//Lease Is Free you Can Have it.
return
}
if lease.Status != leasepool.Free && bytes.Equal(lease.MACAddress, packet.CHAddr()) {
if bytes.Equal(lease.MACAddress, packet.CHAddr()) &&
bytes.Equal(lease.ClientID, clientID) {
//Lease isn't free but it's yours
return
}
@ -522,7 +536,7 @@ func (s *Server) GetLease(packet dhcp4.Packet) (found bool, lease leasepool.Leas
}
//Ok Even if you requested an IP you can't have it.
found, lease, err = s.leasePool.GetLeaseForHardwareAddress(packet.CHAddr())
found, lease, err = s.leasePool.GetLeaseForClient(packet.CHAddr(), clientID)
if found || err != nil {
return
}