From 79fe68b35f6f59a0632bee83da9ced712e30faf3 Mon Sep 17 00:00:00 2001 From: Simon Zolin Date: Mon, 18 May 2020 17:06:27 +0300 Subject: [PATCH] dynamic leases --- dhcpd/dhcpd.go | 1 + dhcpd/v6.go | 151 +++++++++++++++++++++++++++++++++++++---------- dhcpd/v6_test.go | 65 ++++++++++++++++++++ 3 files changed, 186 insertions(+), 31 deletions(-) diff --git a/dhcpd/dhcpd.go b/dhcpd/dhcpd.go index c8e12b9a..7df478f5 100644 --- a/dhcpd/dhcpd.go +++ b/dhcpd/dhcpd.go @@ -147,6 +147,7 @@ func Create(config ServerConfig) *Server { return &s } +// v6 server calls this function after DB is updated func (s *Server) notify6(flags uint32) { s.dbStore() } diff --git a/dhcpd/v6.go b/dhcpd/v6.go index 4eba42c1..f3bfa014 100644 --- a/dhcpd/v6.go +++ b/dhcpd/v6.go @@ -48,8 +48,16 @@ func (s *V6Server) GetLeases(flags int) []Lease { var result []Lease s.leasesLock.Lock() for _, lease := range s.leases { - if (flags&LeasesStatic) != 0 && lease.Expiry.Unix() == leaseExpireStatic { - result = append(result, *lease) + + if lease.Expiry.Unix() == leaseExpireStatic { + if (flags & LeasesStatic) != 0 { + result = append(result, *lease) + } + + } else { + if (flags & LeasesDynamic) != 0 { + result = append(result, *lease) + } } } s.leasesLock.Unlock() @@ -133,6 +141,7 @@ func (s *V6Server) rmLease(l Lease) error { return nil } +// Find lease by MAC func (s *V6Server) findLease(mac net.HardwareAddr) *Lease { s.leasesLock.Lock() defer s.leasesLock.Unlock() @@ -145,6 +154,30 @@ func (s *V6Server) findLease(mac net.HardwareAddr) *Lease { return nil } +// Reserve lease for MAC +func (s *V6Server) reserveLease(mac net.HardwareAddr) *Lease { + l := Lease{} + l.HWAddr = make([]byte, 6) + copy(l.HWAddr, mac) + l.IP = make([]byte, 16) + + s.leasesLock.Lock() + defer s.leasesLock.Unlock() + + copy(l.IP, s.conf.ipStart) + if s.conf.ipStart[15] == 0xff { + return nil + } + s.conf.ipStart[15]++ + + err := s.addLease(l) + if err != nil { + return nil + } + return &l +} + +// Check Client ID func (s *V6Server) checkCID(msg *dhcpv6.Message) error { if msg.Options.ClientID() == nil { return fmt.Errorf("DHCPv6: no ClientID option in request") @@ -152,7 +185,7 @@ func (s *V6Server) checkCID(msg *dhcpv6.Message) error { return nil } -// ServerID policy +// Check ServerID policy func (s *V6Server) checkSID(msg *dhcpv6.Message) error { sid := msg.Options.ServerID() @@ -182,6 +215,64 @@ func (s *V6Server) checkSID(msg *dhcpv6.Message) error { return nil } +// . IAID must be equal to this server's ID +// . IAAddress must be equal to the lease's IP +func (s *V6Server) checkIA(msg *dhcpv6.Message, lease *Lease) error { + switch msg.Type() { + case dhcpv6.MessageTypeRequest, + dhcpv6.MessageTypeConfirm, + dhcpv6.MessageTypeRenew, + dhcpv6.MessageTypeRebind: + + oia := msg.Options.OneIANA() + if oia == nil { + return fmt.Errorf("no IANA option in %s", msg.Type().String()) + } + + if !bytes.Equal(oia.IaId[:], []byte(valueIAID)) { + return fmt.Errorf("invalid IANA.ID value in %s", msg.Type().String()) + } + + oiaAddr := oia.Options.OneAddress() + if oiaAddr == nil { + return fmt.Errorf("no IANA.Addr option in %s", msg.Type().String()) + } + + if !oiaAddr.IPv6Addr.Equal(lease.IP) { + return fmt.Errorf("invalid IANA.Addr option in %s", msg.Type().String()) + } + } + return nil +} + +// Store lease in DB (if necessary) and return lease life time +func (s *V6Server) commitLease(msg *dhcpv6.Message, lease *Lease) time.Duration { + lifetime := s.conf.leaseTime + + switch msg.Type() { + case dhcpv6.MessageTypeSolicit: + // + + case dhcpv6.MessageTypeConfirm: + lifetime = lease.Expiry.Sub(time.Now()) + + case dhcpv6.MessageTypeRequest, + dhcpv6.MessageTypeRenew, + dhcpv6.MessageTypeRebind: + + if lease.Expiry.Unix() != leaseExpireStatic { + + lease.Expiry = time.Now().Add(s.conf.leaseTime) + + s.leasesLock.Lock() + s.conf.notify(LeaseChangedAdded) + s.leasesLock.Unlock() + } + } + return lifetime +} + +// Find a lease associated with MAC and prepare response func (s *V6Server) process(msg *dhcpv6.Message, req dhcpv6.DHCPv6, resp dhcpv6.DHCPv6) bool { switch msg.Type() { case dhcpv6.MessageTypeSolicit, @@ -189,7 +280,7 @@ func (s *V6Server) process(msg *dhcpv6.Message, req dhcpv6.DHCPv6, resp dhcpv6.D dhcpv6.MessageTypeConfirm, dhcpv6.MessageTypeRenew, dhcpv6.MessageTypeRebind: - // break + // continue default: return false @@ -204,42 +295,38 @@ func (s *V6Server) process(msg *dhcpv6.Message, req dhcpv6.DHCPv6, resp dhcpv6.D lease := s.findLease(mac) if lease == nil { log.Debug("DHCPv6: no lease for: %s", mac) + + switch msg.Type() { + + case dhcpv6.MessageTypeSolicit: + lease = s.reserveLease(mac) + if lease == nil { + return false + } + + default: + return false + } + } + + err = s.checkIA(msg, lease) + if err != nil { + log.Debug("DHCPv6: %s", mac) return false } - switch msg.Type() { - case dhcpv6.MessageTypeRequest, - dhcpv6.MessageTypeConfirm, - dhcpv6.MessageTypeRenew, - dhcpv6.MessageTypeRebind: - oia := msg.Options.OneIANA() - if oia == nil { - log.Debug("DHCPv6: no IANA option in %s", msg.Type().String()) - return false - } - if !bytes.Equal(oia.IaId[:], []byte(valueIAID)) { - log.Debug("DHCPv6: invalid IANA.ID value in %s", msg.Type().String()) - return false - } - oiaAddr := oia.Options.OneAddress() - if oiaAddr == nil { - log.Debug("DHCPv6: no IANA.Addr option in %s", msg.Type().String()) - return false - } - if !oiaAddr.IPv6Addr.Equal(lease.IP) { - log.Debug("DHCPv6: invalid IANA.Addr option in %s", msg.Type().String()) - return false - } - } + lifetime := s.commitLease(msg, lease) oia := &dhcpv6.OptIANA{} copy(oia.IaId[:], []byte(valueIAID)) oiaAddr := &dhcpv6.OptIAAddress{ IPv6Addr: lease.IP, - PreferredLifetime: s.conf.leaseTime, - ValidLifetime: s.conf.leaseTime, + PreferredLifetime: lifetime, + ValidLifetime: lifetime, + } + oia.Options = dhcpv6.IdentityOptions{ + Options: []dhcpv6.Option{oiaAddr}, } - oia.Options = dhcpv6.IdentityOptions{Options: []dhcpv6.Option{oiaAddr}} resp.AddOption(oia) if msg.IsOptionRequested(dhcpv6.OptionDNSRecursiveNameServer) { @@ -322,6 +409,7 @@ func (s *V6Server) packetHandler(conn net.PacketConn, peer net.Addr, req dhcpv6. } } +// Get IPv6 address list func getIfaceIPv6(iface net.Interface) []net.IP { addrs, err := iface.Addrs() if err != nil { @@ -391,6 +479,7 @@ func (s *V6Server) Stop() { // now server.Serve() will return } +// Create DHCPv6 server func v6Create(conf V6ServerConf) (*V6Server, error) { s := &V6Server{} s.conf = conf diff --git a/dhcpd/v6_test.go b/dhcpd/v6_test.go index 60885a05..4afe8827 100644 --- a/dhcpd/v6_test.go +++ b/dhcpd/v6_test.go @@ -86,9 +86,11 @@ func TestV6GetLease(t *testing.T) { resp.AddOption(dhcpv6.OptServerID(s.conf.sid)) // check "Advertise" + assert.Equal(t, dhcpv6.MessageTypeAdvertise, resp.Type()) oia := resp.Options.OneIANA() oiaAddr := oia.Options.OneAddress() assert.Equal(t, "2001::1", oiaAddr.IPv6Addr.String()) + assert.Equal(t, s.conf.leaseTime.Seconds(), oiaAddr.ValidLifetime.Seconds()) // "Request" req, _ = dhcpv6.NewRequestFromAdvertise(resp) @@ -97,12 +99,75 @@ func TestV6GetLease(t *testing.T) { assert.True(t, s.process(msg, req, resp)) // check "Reply" + assert.Equal(t, dhcpv6.MessageTypeReply, resp.Type()) oia = resp.Options.OneIANA() oiaAddr = oia.Options.OneAddress() assert.Equal(t, "2001::1", oiaAddr.IPv6Addr.String()) + assert.Equal(t, s.conf.leaseTime.Seconds(), oiaAddr.ValidLifetime.Seconds()) + dnsAddrs := resp.Options.DNS() assert.Equal(t, 1, len(dnsAddrs)) assert.Equal(t, "2000::1", dnsAddrs[0].String()) + // check lease + ls := s.GetLeases(LeasesStatic) + assert.Equal(t, 1, len(ls)) + assert.Equal(t, "2001::1", ls[0].IP.String()) + assert.Equal(t, "aa:aa:aa:aa:aa:aa", ls[0].HWAddr.String()) + + s.Stop() +} + +func TestV6GetDynamicLease(t *testing.T) { + conf := V6ServerConf{ + Enabled: true, + RangeStart: "2001::2", + notify: notify, + } + s, err := v6Create(conf) + assert.True(t, err == nil) + s.conf.dnsIPAddrs = []net.IP{net.ParseIP("2000::1")} + s.conf.sid = dhcpv6.Duid{ + Type: dhcpv6.DUID_LLT, + HwType: iana.HWTypeEthernet, + } + s.conf.sid.LinkLayerAddr, _ = net.ParseMAC("aa:aa:aa:aa:aa:aa") + + // "Solicit" + mac, _ := net.ParseMAC("aa:aa:aa:aa:aa:aa") + req, _ := dhcpv6.NewSolicit(mac) + msg, _ := req.GetInnerMessage() + resp, _ := dhcpv6.NewAdvertiseFromSolicit(msg) + assert.True(t, s.process(msg, req, resp)) + resp.AddOption(dhcpv6.OptServerID(s.conf.sid)) + + // check "Advertise" + assert.Equal(t, dhcpv6.MessageTypeAdvertise, resp.Type()) + oia := resp.Options.OneIANA() + oiaAddr := oia.Options.OneAddress() + assert.Equal(t, "2001::2", oiaAddr.IPv6Addr.String()) + + // "Request" + req, _ = dhcpv6.NewRequestFromAdvertise(resp) + msg, _ = req.GetInnerMessage() + resp, _ = dhcpv6.NewReplyFromMessage(msg) + assert.True(t, s.process(msg, req, resp)) + + // check "Reply" + assert.Equal(t, dhcpv6.MessageTypeReply, resp.Type()) + oia = resp.Options.OneIANA() + oiaAddr = oia.Options.OneAddress() + assert.Equal(t, "2001::2", oiaAddr.IPv6Addr.String()) + + dnsAddrs := resp.Options.DNS() + assert.Equal(t, 1, len(dnsAddrs)) + assert.Equal(t, "2000::1", dnsAddrs[0].String()) + + // check lease + ls := s.GetLeases(LeasesDynamic) + assert.Equal(t, 1, len(ls)) + assert.Equal(t, "2001::2", ls[0].IP.String()) + assert.Equal(t, "aa:aa:aa:aa:aa:aa", ls[0].HWAddr.String()) + s.Stop() }