//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris // +build aix darwin dragonfly freebsd linux netbsd openbsd solaris package dhcpd import ( "fmt" "net" "strings" "testing" "time" "github.com/AdguardTeam/AdGuardHome/internal/aghnet" "github.com/AdguardTeam/golibs/netutil" "github.com/AdguardTeam/golibs/stringutil" "github.com/AdguardTeam/golibs/testutil" "github.com/insomniacslk/dhcp/dhcpv4" "github.com/stretchr/testify/assert" "github.com/stretchr/testify/require" //lint:ignore SA1019 See the TODO in go.mod. "github.com/mdlayher/raw" ) var ( DefaultRangeStart = net.IP{192, 168, 10, 100} DefaultRangeEnd = net.IP{192, 168, 10, 200} DefaultGatewayIP = net.IP{192, 168, 10, 1} DefaultSelfIP = net.IP{192, 168, 10, 2} DefaultSubnetMask = net.IP{255, 255, 255, 0} ) func notify4(flags uint32) { } // defaultV4ServerConf returns the default configuration for *v4Server to use in // tests. func defaultV4ServerConf() (conf V4ServerConf) { return V4ServerConf{ Enabled: true, RangeStart: DefaultRangeStart, RangeEnd: DefaultRangeEnd, GatewayIP: DefaultGatewayIP, SubnetMask: DefaultSubnetMask, notify: notify4, dnsIPAddrs: []net.IP{DefaultSelfIP}, } } // defaultSrv prepares the default DHCPServer to use in tests. The underlying // type of s is *v4Server. func defaultSrv(t *testing.T) (s DHCPServer) { t.Helper() var err error s, err = v4Create(defaultV4ServerConf()) require.NoError(t, err) return s } func TestV4Server_leasing(t *testing.T) { const ( staticName = "static-client" anotherName = "another-client" ) staticIP := net.IP{192, 168, 10, 10} anotherIP := DefaultRangeStart staticMAC := net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA} anotherMAC := net.HardwareAddr{0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB} s := defaultSrv(t) t.Run("add_static", func(t *testing.T) { err := s.AddStaticLease(&Lease{ Expiry: time.Unix(leaseExpireStatic, 0), Hostname: staticName, HWAddr: staticMAC, IP: staticIP, }) require.NoError(t, err) t.Run("same_name", func(t *testing.T) { err = s.AddStaticLease(&Lease{ Expiry: time.Unix(leaseExpireStatic, 0), Hostname: staticName, HWAddr: anotherMAC, IP: anotherIP, }) assert.ErrorIs(t, err, ErrDupHostname) }) t.Run("same_mac", func(t *testing.T) { wantErrMsg := "dhcpv4: adding static lease: removing " + "dynamic leases for " + anotherIP.String() + " (" + staticMAC.String() + "): static lease already exists" err = s.AddStaticLease(&Lease{ Expiry: time.Unix(leaseExpireStatic, 0), Hostname: anotherName, HWAddr: staticMAC, IP: anotherIP, }) testutil.AssertErrorMsg(t, wantErrMsg, err) }) t.Run("same_ip", func(t *testing.T) { wantErrMsg := "dhcpv4: adding static lease: removing " + "dynamic leases for " + staticIP.String() + " (" + anotherMAC.String() + "): static lease already exists" err = s.AddStaticLease(&Lease{ Expiry: time.Unix(leaseExpireStatic, 0), Hostname: anotherName, HWAddr: anotherMAC, IP: staticIP, }) testutil.AssertErrorMsg(t, wantErrMsg, err) }) }) t.Run("add_dynamic", func(t *testing.T) { s4, ok := s.(*v4Server) require.True(t, ok) discoverAnOffer := func( t *testing.T, name string, ip net.IP, mac net.HardwareAddr, ) (resp *dhcpv4.DHCPv4) { testutil.CleanupAndRequireSuccess(t, func() (err error) { return s.ResetLeases(s.GetLeases(LeasesStatic)) }) req, err := dhcpv4.NewDiscovery( mac, dhcpv4.WithOption(dhcpv4.OptHostName(name)), dhcpv4.WithOption(dhcpv4.OptRequestedIPAddress(ip)), dhcpv4.WithOption(dhcpv4.OptClientIdentifier([]byte{1, 2, 3, 4, 5, 6, 8})), dhcpv4.WithGatewayIP(DefaultGatewayIP), ) require.NoError(t, err) resp = &dhcpv4.DHCPv4{} res := s4.handle(req, resp) require.Positive(t, res) require.Equal(t, dhcpv4.MessageTypeOffer, resp.MessageType()) resp.ClientHWAddr = mac return resp } t.Run("same_name", func(t *testing.T) { resp := discoverAnOffer(t, staticName, anotherIP, anotherMAC) req, err := dhcpv4.NewRequestFromOffer(resp, dhcpv4.WithOption( dhcpv4.OptHostName(staticName), )) require.NoError(t, err) res := s4.handle(req, resp) require.Positive(t, res) assert.Equal(t, aghnet.GenerateHostname(resp.YourIPAddr), resp.HostName()) }) t.Run("same_mac", func(t *testing.T) { resp := discoverAnOffer(t, anotherName, anotherIP, staticMAC) req, err := dhcpv4.NewRequestFromOffer(resp, dhcpv4.WithOption( dhcpv4.OptHostName(anotherName), )) require.NoError(t, err) res := s4.handle(req, resp) require.Positive(t, res) fqdnOptData := resp.Options.Get(dhcpv4.OptionFQDN) require.Len(t, fqdnOptData, 3+len(staticName)) assert.Equal(t, []uint8(staticName), fqdnOptData[3:]) assert.Equal(t, staticIP, resp.YourIPAddr) }) t.Run("same_ip", func(t *testing.T) { resp := discoverAnOffer(t, anotherName, staticIP, anotherMAC) req, err := dhcpv4.NewRequestFromOffer(resp, dhcpv4.WithOption( dhcpv4.OptHostName(anotherName), )) require.NoError(t, err) res := s4.handle(req, resp) require.Positive(t, res) assert.NotEqual(t, staticIP, resp.YourIPAddr) }) }) } func TestV4Server_AddRemove_static(t *testing.T) { s := defaultSrv(t) ls := s.GetLeases(LeasesStatic) require.Empty(t, ls) testCases := []struct { lease *Lease name string wantErrMsg string }{{ lease: &Lease{ Hostname: "success.local", HWAddr: net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}, IP: net.IP{192, 168, 10, 150}, }, name: "success", wantErrMsg: "", }, { lease: &Lease{ Hostname: "probably-router.local", HWAddr: net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}, IP: DefaultGatewayIP, }, name: "with_gateway_ip", wantErrMsg: "dhcpv4: adding static lease: " + "can't assign the gateway IP 192.168.10.1 to the lease", }, { lease: &Lease{ Hostname: "ip6.local", HWAddr: net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}, IP: net.ParseIP("ffff::1"), }, name: "ipv6", wantErrMsg: `dhcpv4: adding static lease: ` + `invalid ip "ffff::1", only ipv4 is supported`, }, { lease: &Lease{ Hostname: "bad-mac.local", HWAddr: net.HardwareAddr{0xAA, 0xAA}, IP: net.IP{192, 168, 10, 150}, }, name: "bad_mac", wantErrMsg: `dhcpv4: adding static lease: bad mac address "aa:aa": ` + `bad mac address length 2, allowed: [6 8 20]`, }, { lease: &Lease{ Hostname: "bad-lbl-.local", HWAddr: net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}, IP: net.IP{192, 168, 10, 150}, }, name: "bad_hostname", wantErrMsg: `dhcpv4: adding static lease: validating hostname: ` + `bad domain name "bad-lbl-.local": ` + `bad domain name label "bad-lbl-": bad domain name label rune '-'`, }} for _, tc := range testCases { t.Run(tc.name, func(t *testing.T) { err := s.AddStaticLease(tc.lease) testutil.AssertErrorMsg(t, tc.wantErrMsg, err) if tc.wantErrMsg != "" { return } err = s.RemoveStaticLease(&Lease{ IP: tc.lease.IP, HWAddr: tc.lease.HWAddr, }) diffErrMsg := fmt.Sprintf("dhcpv4: lease for ip %s is different: %+v", tc.lease.IP, tc.lease) testutil.AssertErrorMsg(t, diffErrMsg, err) // Remove static lease. err = s.RemoveStaticLease(tc.lease) require.NoError(t, err) }) ls = s.GetLeases(LeasesStatic) require.Emptyf(t, ls, "after %s", tc.name) } } func TestV4_AddReplace(t *testing.T) { sIface := defaultSrv(t) s, ok := sIface.(*v4Server) require.True(t, ok) dynLeases := []Lease{{ Hostname: "dynamic-1.local", HWAddr: net.HardwareAddr{0x11, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}, IP: net.IP{192, 168, 10, 150}, }, { Hostname: "dynamic-2.local", HWAddr: net.HardwareAddr{0x22, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}, IP: net.IP{192, 168, 10, 151}, }} for i := range dynLeases { err := s.addLease(&dynLeases[i]) require.NoError(t, err) } stLeases := []*Lease{{ Hostname: "static-1.local", HWAddr: net.HardwareAddr{0x33, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}, IP: net.IP{192, 168, 10, 150}, }, { Hostname: "static-2.local", HWAddr: net.HardwareAddr{0x22, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}, IP: net.IP{192, 168, 10, 152}, }} for _, l := range stLeases { err := s.AddStaticLease(l) require.NoError(t, err) } ls := s.GetLeases(LeasesStatic) require.Len(t, ls, 2) for i, l := range ls { assert.True(t, stLeases[i].IP.Equal(l.IP)) assert.Equal(t, stLeases[i].HWAddr, l.HWAddr) assert.True(t, l.IsStatic()) } } func TestV4Server_handle_optionsPriority(t *testing.T) { defaultIP := net.IP{192, 168, 1, 1} knownIP := net.IP{1, 2, 3, 4} // prepareSrv creates a *v4Server and sets the opt6IPs in the initial // configuration of the server as the value for DHCP option 6. prepareSrv := func(t *testing.T, opt6IPs []net.IP) (s *v4Server) { t.Helper() conf := defaultV4ServerConf() if len(opt6IPs) > 0 { b := &strings.Builder{} stringutil.WriteToBuilder(b, "6 ips ", opt6IPs[0].String()) for _, ip := range opt6IPs[1:] { stringutil.WriteToBuilder(b, ",", ip.String()) } conf.Options = []string{b.String()} } else { defer func() { s.implicitOpts.Update(dhcpv4.OptDNS(defaultIP)) }() } ss, err := v4Create(conf) require.NoError(t, err) var ok bool s, ok = ss.(*v4Server) require.True(t, ok) s.conf.dnsIPAddrs = []net.IP{defaultIP} return s } // checkResp creates a discovery message with DHCP option 6 requested amd // asserts the response to contain wantIPs in this option. checkResp := func(t *testing.T, s *v4Server, wantIPs []net.IP) { t.Helper() mac := net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA} req, err := dhcpv4.NewDiscovery(mac, dhcpv4.WithRequestedOptions( dhcpv4.OptionDomainNameServer, )) require.NoError(t, err) var resp *dhcpv4.DHCPv4 resp, err = dhcpv4.NewReplyFromRequest(req) require.NoError(t, err) res := s.handle(req, resp) require.Equal(t, 1, res) o := resp.GetOneOption(dhcpv4.OptionDomainNameServer) require.NotEmpty(t, o) wantData := []byte{} for _, ip := range wantIPs { wantData = append(wantData, ip...) } assert.Equal(t, o, wantData) } t.Run("default", func(t *testing.T) { s := prepareSrv(t, nil) checkResp(t, s, []net.IP{defaultIP}) }) t.Run("explicitly_configured", func(t *testing.T) { s := prepareSrv(t, []net.IP{knownIP, knownIP}) checkResp(t, s, []net.IP{knownIP, knownIP}) }) } func TestV4Server_updateOptions(t *testing.T) { testIP := net.IP{1, 2, 3, 4} dontWant := func(c dhcpv4.OptionCode) (opt dhcpv4.Option) { return dhcpv4.OptGeneric(c, nil) } testCases := []struct { name string wantOpts dhcpv4.Options reqMods []dhcpv4.Modifier confOpts []string }{{ name: "requested_default", wantOpts: dhcpv4.OptionsFromList( dhcpv4.OptBroadcastAddress(netutil.IPv4bcast()), ), reqMods: []dhcpv4.Modifier{ dhcpv4.WithRequestedOptions(dhcpv4.OptionBroadcastAddress), }, confOpts: nil, }, { name: "requested_non-default", wantOpts: dhcpv4.OptionsFromList( dhcpv4.OptBroadcastAddress(testIP), ), reqMods: []dhcpv4.Modifier{ dhcpv4.WithRequestedOptions(dhcpv4.OptionBroadcastAddress), }, confOpts: []string{ fmt.Sprintf("%d ip %s", dhcpv4.OptionBroadcastAddress, testIP), }, }, { name: "non-requested_default", wantOpts: dhcpv4.OptionsFromList( dontWant(dhcpv4.OptionBroadcastAddress), ), reqMods: nil, confOpts: nil, }, { name: "non-requested_non-default", wantOpts: dhcpv4.OptionsFromList( dhcpv4.OptBroadcastAddress(testIP), ), reqMods: nil, confOpts: []string{ fmt.Sprintf("%d ip %s", dhcpv4.OptionBroadcastAddress, testIP), }, }, { name: "requested_deleted", wantOpts: dhcpv4.OptionsFromList( dontWant(dhcpv4.OptionBroadcastAddress), ), reqMods: []dhcpv4.Modifier{ dhcpv4.WithRequestedOptions(dhcpv4.OptionBroadcastAddress), }, confOpts: []string{ fmt.Sprintf("%d del", dhcpv4.OptionBroadcastAddress), }, }, { name: "requested_non-default_deleted", wantOpts: dhcpv4.OptionsFromList( dontWant(dhcpv4.OptionBroadcastAddress), ), reqMods: []dhcpv4.Modifier{ dhcpv4.WithRequestedOptions(dhcpv4.OptionBroadcastAddress), }, confOpts: []string{ fmt.Sprintf("%d ip %s", dhcpv4.OptionBroadcastAddress, testIP), fmt.Sprintf("%d del", dhcpv4.OptionBroadcastAddress), }, }} for _, tc := range testCases { req, err := dhcpv4.New(tc.reqMods...) require.NoError(t, err) resp, err := dhcpv4.NewReplyFromRequest(req) require.NoError(t, err) conf := defaultV4ServerConf() conf.Options = tc.confOpts s, err := v4Create(conf) require.NoError(t, err) require.IsType(t, (*v4Server)(nil), s) s4, _ := s.(*v4Server) t.Run(tc.name, func(t *testing.T) { s4.updateOptions(req, resp) for c, v := range tc.wantOpts { if v == nil { assert.NotContains(t, resp.Options, c) continue } assert.Equal(t, v, resp.Options.Get(dhcpv4.GenericOptionCode(c))) } }) } } func TestV4StaticLease_Get(t *testing.T) { sIface := defaultSrv(t) s, ok := sIface.(*v4Server) require.True(t, ok) s.conf.dnsIPAddrs = []net.IP{{192, 168, 10, 1}} s.implicitOpts.Update(dhcpv4.OptDNS(s.conf.dnsIPAddrs...)) l := &Lease{ Hostname: "static-1.local", HWAddr: net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}, IP: net.IP{192, 168, 10, 150}, } err := s.AddStaticLease(l) require.NoError(t, err) var req, resp *dhcpv4.DHCPv4 mac := net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA} t.Run("discover", func(t *testing.T) { req, err = dhcpv4.NewDiscovery(mac, dhcpv4.WithRequestedOptions( dhcpv4.OptionDomainNameServer, )) require.NoError(t, err) resp, err = dhcpv4.NewReplyFromRequest(req) require.NoError(t, err) assert.Equal(t, 1, s.handle(req, resp)) }) // Don't continue if we got any errors in the previous subtest. require.NoError(t, err) t.Run("offer", func(t *testing.T) { assert.Equal(t, dhcpv4.MessageTypeOffer, resp.MessageType()) assert.Equal(t, mac, resp.ClientHWAddr) assert.True(t, l.IP.Equal(resp.YourIPAddr)) assert.True(t, s.conf.GatewayIP.Equal(resp.Router()[0])) assert.True(t, s.conf.GatewayIP.Equal(resp.ServerIdentifier())) assert.Equal(t, s.conf.subnet.Mask, resp.SubnetMask()) assert.Equal(t, s.conf.leaseTime.Seconds(), resp.IPAddressLeaseTime(-1).Seconds()) }) t.Run("request", func(t *testing.T) { req, err = dhcpv4.NewRequestFromOffer(resp) require.NoError(t, err) resp, err = dhcpv4.NewReplyFromRequest(req) require.NoError(t, err) assert.Equal(t, 1, s.handle(req, resp)) }) require.NoError(t, err) t.Run("ack", func(t *testing.T) { assert.Equal(t, dhcpv4.MessageTypeAck, resp.MessageType()) assert.Equal(t, mac, resp.ClientHWAddr) assert.True(t, l.IP.Equal(resp.YourIPAddr)) assert.True(t, s.conf.GatewayIP.Equal(resp.Router()[0])) assert.True(t, s.conf.GatewayIP.Equal(resp.ServerIdentifier())) assert.Equal(t, s.conf.subnet.Mask, resp.SubnetMask()) assert.Equal(t, s.conf.leaseTime.Seconds(), resp.IPAddressLeaseTime(-1).Seconds()) }) dnsAddrs := resp.DNS() require.Len(t, dnsAddrs, 1) assert.True(t, s.conf.GatewayIP.Equal(dnsAddrs[0])) t.Run("check_lease", func(t *testing.T) { ls := s.GetLeases(LeasesStatic) require.Len(t, ls, 1) assert.True(t, l.IP.Equal(ls[0].IP)) assert.Equal(t, mac, ls[0].HWAddr) }) } func TestV4DynamicLease_Get(t *testing.T) { conf := defaultV4ServerConf() conf.Options = []string{ "81 hex 303132", "82 ip 1.2.3.4", } var err error sIface, err := v4Create(conf) require.NoError(t, err) s, ok := sIface.(*v4Server) require.True(t, ok) s.conf.dnsIPAddrs = []net.IP{{192, 168, 10, 1}} s.implicitOpts.Update(dhcpv4.OptDNS(s.conf.dnsIPAddrs...)) var req, resp *dhcpv4.DHCPv4 mac := net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA} t.Run("discover", func(t *testing.T) { req, err = dhcpv4.NewDiscovery(mac, dhcpv4.WithRequestedOptions( dhcpv4.OptionFQDN, dhcpv4.OptionRelayAgentInformation, )) require.NoError(t, err) resp, err = dhcpv4.NewReplyFromRequest(req) require.NoError(t, err) assert.Equal(t, 1, s.handle(req, resp)) }) // Don't continue if we got any errors in the previous subtest. require.NoError(t, err) t.Run("offer", func(t *testing.T) { assert.Equal(t, dhcpv4.MessageTypeOffer, resp.MessageType()) assert.Equal(t, mac, resp.ClientHWAddr) assert.Equal(t, s.conf.RangeStart, resp.YourIPAddr) assert.Equal(t, s.conf.GatewayIP, resp.ServerIdentifier()) router := resp.Router() require.Len(t, router, 1) assert.Equal(t, s.conf.GatewayIP, router[0]) assert.Equal(t, s.conf.subnet.Mask, resp.SubnetMask()) assert.Equal(t, s.conf.leaseTime.Seconds(), resp.IPAddressLeaseTime(-1).Seconds()) assert.Equal(t, []byte("012"), resp.Options.Get(dhcpv4.OptionFQDN)) rai := resp.RelayAgentInfo() require.NotNil(t, rai) assert.Equal(t, net.IP{1, 2, 3, 4}, net.IP(rai.ToBytes())) }) t.Run("request", func(t *testing.T) { req, err = dhcpv4.NewRequestFromOffer(resp) require.NoError(t, err) resp, err = dhcpv4.NewReplyFromRequest(req) require.NoError(t, err) assert.Equal(t, 1, s.handle(req, resp)) }) require.NoError(t, err) t.Run("ack", func(t *testing.T) { assert.Equal(t, dhcpv4.MessageTypeAck, resp.MessageType()) assert.Equal(t, mac, resp.ClientHWAddr) assert.True(t, s.conf.RangeStart.Equal(resp.YourIPAddr)) router := resp.Router() require.Len(t, router, 1) assert.Equal(t, s.conf.GatewayIP, router[0]) assert.True(t, s.conf.GatewayIP.Equal(resp.ServerIdentifier())) assert.Equal(t, s.conf.subnet.Mask, resp.SubnetMask()) assert.Equal(t, s.conf.leaseTime.Seconds(), resp.IPAddressLeaseTime(-1).Seconds()) }) dnsAddrs := resp.DNS() require.Len(t, dnsAddrs, 1) assert.True(t, net.IP{192, 168, 10, 1}.Equal(dnsAddrs[0])) // check lease t.Run("check_lease", func(t *testing.T) { ls := s.GetLeases(LeasesDynamic) require.Len(t, ls, 1) assert.True(t, net.IP{192, 168, 10, 100}.Equal(ls[0].IP)) assert.Equal(t, mac, ls[0].HWAddr) }) } func TestNormalizeHostname(t *testing.T) { testCases := []struct { name string hostname string wantErrMsg string want string }{{ name: "success", hostname: "example.com", wantErrMsg: "", want: "example.com", }, { name: "success_empty", hostname: "", wantErrMsg: "", want: "", }, { name: "success_spaces", hostname: "my device 01", wantErrMsg: "", want: "my-device-01", }, { name: "success_underscores", hostname: "my_device_01", wantErrMsg: "", want: "my-device-01", }, { name: "error_part", hostname: "device !!!", wantErrMsg: "", want: "device", }, { name: "error_part_spaces", hostname: "device ! ! !", wantErrMsg: "", want: "device", }, { name: "error", hostname: "!!!", wantErrMsg: `normalizing "!!!": no valid parts`, want: "", }, { name: "error_spaces", hostname: "! ! !", wantErrMsg: `normalizing "! ! !": no valid parts`, want: "", }} for _, tc := range testCases { t.Run(tc.name, func(t *testing.T) { got, err := normalizeHostname(tc.hostname) testutil.AssertErrorMsg(t, tc.wantErrMsg, err) assert.Equal(t, tc.want, got) }) } } // fakePacketConn is a mock implementation of net.PacketConn to simplify // testing. type fakePacketConn struct { // writeTo is used to substitute net.PacketConn's WriteTo method. writeTo func(p []byte, addr net.Addr) (n int, err error) // net.PacketConn is embedded here simply to make *fakePacketConn a // net.PacketConn without actually implementing all methods. net.PacketConn } // WriteTo implements net.PacketConn interface for *fakePacketConn. func (fc *fakePacketConn) WriteTo(p []byte, addr net.Addr) (n int, err error) { return fc.writeTo(p, addr) } func TestV4Server_Send(t *testing.T) { s := &v4Server{} var ( defaultIP = net.IP{99, 99, 99, 99} knownIP = net.IP{4, 2, 4, 2} knownMAC = net.HardwareAddr{6, 5, 4, 3, 2, 1} ) defaultPeer := &net.UDPAddr{ IP: defaultIP, // Use neither client nor server port to check it actually // changed. Port: dhcpv4.ClientPort + dhcpv4.ServerPort, } defaultResp := &dhcpv4.DHCPv4{} testCases := []struct { want net.Addr req *dhcpv4.DHCPv4 resp *dhcpv4.DHCPv4 name string }{{ name: "giaddr", req: &dhcpv4.DHCPv4{GatewayIPAddr: knownIP}, resp: defaultResp, want: &net.UDPAddr{ IP: knownIP, Port: dhcpv4.ServerPort, }, }, { name: "nak", req: &dhcpv4.DHCPv4{}, resp: &dhcpv4.DHCPv4{ Options: dhcpv4.OptionsFromList( dhcpv4.OptMessageType(dhcpv4.MessageTypeNak), ), }, want: defaultPeer, }, { name: "ciaddr", req: &dhcpv4.DHCPv4{ClientIPAddr: knownIP}, resp: &dhcpv4.DHCPv4{}, want: &net.UDPAddr{ IP: knownIP, Port: dhcpv4.ClientPort, }, }, { name: "chaddr", req: &dhcpv4.DHCPv4{ClientHWAddr: knownMAC}, resp: &dhcpv4.DHCPv4{YourIPAddr: knownIP}, want: &dhcpUnicastAddr{ Addr: raw.Addr{HardwareAddr: knownMAC}, yiaddr: knownIP, }, }, { name: "who_are_you", req: &dhcpv4.DHCPv4{}, resp: &dhcpv4.DHCPv4{}, want: defaultPeer, }} for _, tc := range testCases { t.Run(tc.name, func(t *testing.T) { conn := &fakePacketConn{ writeTo: func(_ []byte, addr net.Addr) (_ int, _ error) { assert.Equal(t, tc.want, addr) return 0, nil }, } s.send(cloneUDPAddr(defaultPeer), conn, tc.req, tc.resp) }) } t.Run("giaddr_nak", func(t *testing.T) { req := &dhcpv4.DHCPv4{ GatewayIPAddr: knownIP, } // Ensure the request is for unicast. req.SetUnicast() resp := &dhcpv4.DHCPv4{ Options: dhcpv4.OptionsFromList( dhcpv4.OptMessageType(dhcpv4.MessageTypeNak), ), } want := &net.UDPAddr{ IP: req.GatewayIPAddr, Port: dhcpv4.ServerPort, } conn := &fakePacketConn{ writeTo: func(_ []byte, addr net.Addr) (n int, err error) { assert.Equal(t, want, addr) return 0, nil }, } s.send(cloneUDPAddr(defaultPeer), conn, req, resp) assert.True(t, resp.IsBroadcast()) }) }