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// +build integration
package dhcpv4
import (
"errors"
"log"
"math/rand"
"net"
"testing"
"time"
"github.com/stretchr/testify/require"
)
func init() {
// initialize seed. This is generally bad, but "good enough"
// to generate random ports for these tests
rand.Seed(time.Now().UTC().UnixNano())
}
func randPort() int {
// can't use port 0 with raw sockets, so until we implement
// a non-raw-sockets client for non-static ports, we have to
// deal with this "randomness"
return 1024 + rand.Intn(65536-1024)
}
// DORAHandler is a server handler suitable for DORA transactions
func DORAHandler(conn net.PacketConn, peer net.Addr, m *DHCPv4) {
if m == nil {
log.Printf("Packet is nil!")
return
}
if m.Opcode() != OpcodeBootRequest {
log.Printf("Not a BootRequest!")
return
}
reply, err := NewReplyFromRequest(m)
if err != nil {
log.Printf("NewReplyFromRequest failed: %v", err)
return
}
reply.AddOption(&OptServerIdentifier{ServerID: net.IP{1, 2, 3, 4}})
opt := m.GetOneOption(OptionDHCPMessageType)
if opt == nil {
log.Printf("No message type found!")
return
}
switch opt.(*OptMessageType).MessageType {
case MessageTypeDiscover:
reply.AddOption(&OptMessageType{MessageType: MessageTypeOffer})
case MessageTypeRequest:
reply.AddOption(&OptMessageType{MessageType: MessageTypeAck})
default:
log.Printf("Unhandled message type: %v", opt.(*OptMessageType).MessageType)
return
}
if _, err := conn.WriteTo(reply.ToBytes(), peer); err != nil {
log.Printf("Cannot reply to client: %v", err)
}
}
// utility function to set up a client and a server instance and run it in
// background. The caller needs to call Server.Close() once finished.
func setUpClientAndServer(handler Handler) (*Client, *Server) {
// strong assumption, I know
loAddr := net.ParseIP("127.0.0.1")
laddr := net.UDPAddr{
IP: loAddr,
Port: randPort(),
}
s := NewServer(laddr, handler)
go s.ActivateAndServe()
c := NewClient()
// FIXME this doesn't deal well with raw sockets, the actual 0 will be used
// in the UDP header as source port
c.LocalAddr = &net.UDPAddr{IP: loAddr, Port: randPort()}
for {
if s.LocalAddr() != nil {
break
}
time.Sleep(10 * time.Millisecond)
log.Printf("Waiting for server to run...")
}
c.RemoteAddr = s.LocalAddr()
log.Printf("Client.RemoteAddr: %s", c.RemoteAddr)
return c, s
}
// utility function to return the loopback interface name
// TODO this is copied from dhcpv6/server_test.go , we should refactor common code in a separate package
func getLoopbackInterface() (string, error) {
var ifaces []net.Interface
var err error
if ifaces, err = net.Interfaces(); err != nil {
return "", err
}
for _, iface := range ifaces {
if iface.Flags&net.FlagLoopback != 0 || iface.Name[:2] == "lo" {
return iface.Name, nil
}
}
return "", errors.New("No loopback interface found")
}
func TestNewServer(t *testing.T) {
laddr := net.UDPAddr{
IP: net.ParseIP("127.0.0.1"),
Port: 0,
}
s := NewServer(laddr, DORAHandler)
defer s.Close()
require.NotNil(t, s)
require.Nil(t, s.conn)
require.Equal(t, laddr, s.localAddr)
require.NotNil(t, s.Handler)
}
func TestServerActivateAndServe(t *testing.T) {
c, s := setUpClientAndServer(DORAHandler)
defer s.Close()
lo, err := getLoopbackInterface()
require.NoError(t, err)
xid := uint32(0xaabbccdd)
hwaddr := [16]byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf}
modifiers := []Modifier{
WithTransactionID(xid),
WithHwAddr(hwaddr[:]),
}
conv, err := c.Exchange(lo, nil, modifiers...)
require.NoError(t, err)
require.Equal(t, 4, len(conv))
for _, p := range conv {
require.Equal(t, xid, p.TransactionID())
require.Equal(t, [16]byte(hwaddr), p.ClientHwAddr())
}
}
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