netboot/pixiecore/dhcp_server.go
David Anderson 99cc04c381 Clean up more lint errors.
Also remove the 'vetshadow' linter, it's overly noisy on normal code.
2018-02-05 21:09:02 -08:00

99 lines
2.1 KiB
Go

// Copyright 2016 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package pixiecore
import (
"errors"
"fmt"
"net"
"go.universe.tf/netboot/dhcp4"
)
type dhcpServer struct {
//dhcpConn *dhcp4.Conn // Used for sending only
//icmpConn icmp.PacketConn
leases []lease
}
const (
leaseFree = iota
leaseReserved
leaseActive
)
type lease struct {
state int
//mac net.HardwareAddr
//expires time.Time
}
func newDHCPServer(address string, dhcpConn *dhcp4.Conn) (*dhcpServer, error) {
var ret dhcpServer
managedNet, err := findIPNet(address)
if err != nil {
return nil, err
}
for ip := managedNet.IP.Mask(managedNet.Mask); managedNet.Contains(ip); ip = nextIP(ip) {
ret.leases = append(ret.leases, lease{})
if ip.Equal(managedNet.IP) {
ret.leases[len(ret.leases)-1].state = leaseActive // Active with no expiry == eternal
}
}
return nil, errors.New("TODO")
}
func nextIP(ip net.IP) net.IP {
ip = ip.To4()
if ip == nil {
return nil
}
ret := net.IPv4(ip[0], ip[1], ip[2], ip[3])
for i := 3; i >= 0; i-- {
ret[i]++
if ret[i] != 0 {
break
}
}
return ret
}
func findIPNet(address string) (*net.IPNet, error) {
wanted := net.ParseIP(address)
if wanted == nil || wanted.To4() == nil {
return nil, fmt.Errorf("Bad IPv4 address %q", address)
}
addrs, err := net.InterfaceAddrs()
if err != nil {
return nil, err
}
for _, addr := range addrs {
ipaddr, ok := addr.(*net.IPNet)
if !ok {
continue
}
if !ipaddr.IP.Equal(wanted) {
continue
}
return ipaddr, nil
}
return nil, fmt.Errorf("IP address %q not found on any network interface", address)
}