Merge pull request #73 from hkwi/radiotap_fcs

FCS may be handled in Radiotap
google · Apr 28, 2015 · 09bce8a · 09bce8a
2 parents 5d988aa + 2f3771a
commit 09bce8a
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Showing 3 changed files with 75 additions and 101 deletions.
diff --git a/layers/dot11.go b/layers/dot11.go
@@ -368,12 +368,8 @@ func (m *Dot11) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
 		offset += 6
 	}
 
-	if mainType == Dot11TypeData {
-		m.BaseLayer = BaseLayer{Contents: data[0:offset], Payload: data[offset:len(data)]}
-	} else {
-		m.BaseLayer = BaseLayer{Contents: data[0:offset], Payload: data[offset : len(data)-4]}
-		m.Checksum = binary.LittleEndian.Uint32(data[len(data)-4 : len(data)])
-	}
+	m.BaseLayer = BaseLayer{Contents: data[0:offset], Payload: data[offset : len(data)-4]}
+	m.Checksum = binary.LittleEndian.Uint32(data[len(data)-4 : len(data)])
 	return nil
 }
 

diff --git a/layers/dot11_test.go b/layers/dot11_test.go
@@ -7,11 +7,11 @@
 package layers
 
 import (
+	"bytes"
 	_ "fmt"
 	"github.com/google/gopacket"
 	"net"
 	"reflect"
-	"bytes"
 	"testing"
 )
 
@@ -102,73 +102,53 @@ func BenchmarkDecodePacketDot11CtrlCTS(b *testing.B) {
 }
 
 // testPacketDot11MgmtBeacon is the packet:
-//   06:14:26.492772 637444841us tsft short preamble 6.0 Mb/s -40dB signal -96dB noise antenna 2 5180 MHz 11a Beacon () [6.0* 9.0 12.0* 18.0 24.0* 36.0 48.0 54.0 Mbit] IBSS CH: 36
-//   	0x0000:  0000 2000 6708 0400 e9a2 fe25 0000 0000  ....g......%....
-//   	0x0010:  220c d8a0 0200 0000 4001 0000 3c14 2411  ".......@...<.$.
-//   	0x0020:  8000 0000 ffff ffff ffff 0003 7f07 a016  ................
-//   	0x0030:  0000 0000 0000 d09b 3840 1028 0000 0000  ........8@.(....
-//   	0x0040:  6400 0005 0000 0108 8c12 9824 b048 606c  d..........$.H`l
-//   	0x0050:  0301 2405 0400 0100 0007 2a55 5320 2401  ..$.......*US.$.
-//   	0x0060:  1128 0111 2c01 1130 0111 3401 1738 0117  .(..,..0..4..8..
-//   	0x0070:  3c01 1740 0117 9501 1e99 011e 9d01 1ea1  <..@............
-//   	0x0080:  011e a501 1e20 0100 dd18 0050 f202 0101  ...........P....
-//   	0x0090:  0000 03a4 0000 27a4 0000 4243 5e00 6232  ......'...BC^.b2
-//   	0x00a0:  2f00 340c 6672 6565 6273 642d 6d65 7368  /.4.freebsd-mesh
-//   	0x00b0:  3317 0100 0fac 0000 0fac 0000 0fac ff00  3...............
-//   	0x00c0:  0fac ff00 0fac ff00 df                   .........
+//   15:44:56.531833 6.0 Mb/s 2412 MHz 11g -81dB signal antenna 5 Beacon (Wi2) [6.0* 9.0 12.0* 18.0 24.0* 36.0 48.0 54.0 Mbit] ESS CH: 1
+//   	0x0000:  0000 1200 2e48 0000 100c 6c09 c000 af05  .....H....l.....
+//   	0x0010:  0000 8000 0000 ffff ffff ffff c08a de01  ................
+//   	0x0020:  11b8 c08a de01 11b8 f097 80f1 30bc 1300  ............0...
+//   	0x0030:  0000 6400 2104 0003 5769 3201 088c 1298  ..d.!...Wi2.....
+//   	0x0040:  24b0 4860 6c03 0101 0504 0001 0000 2a01  $.H`l.........*.
+//   	0x0050:  00dd 1800 50f2 0201 0181 0007 a400 0023  ....P..........#
+//   	0x0060:  a400 0042 435e 0062 322f 00dd 1e00 904c  ...BC^.b2/.....L
+//   	0x0070:  338c 011b ffff 0000 0000 0000 0000 0000  3...............
+//   	0x0080:  1000 0000 0000 0000 0000 002d 1a8c 011b  ...........-....
+//   	0x0090:  ffff 0000 0000 0000 0000 0000 1000 0000  ................
+//   	0x00a0:  0000 0000 0000 00dd 1a00 904c 3401 0000  ...........L4...
+//   	0x00b0:  0000 0000 0000 0000 0000 0000 0000 0000  ................
+//   	0x00c0:  0000 003d 1601 0000 0000 0000 0000 0000  ...=............
+//   	0x00d0:  0000 0000 0000 0000 0000 007f 0400 0000  ................
+//   	0x00e0:  00dd 0800 1392 0100 0185 0094 0b90 15    ...............
 var testPacketDot11MgmtBeacon = []byte{
-	0x00, 0x00, 0x20, 0x00, 0x67, 0x08, 0x04, 0x00, 0xe9, 0xa2, 0xfe, 0x25, 0x00, 0x00, 0x00, 0x00,
-	0x22, 0x0c, 0xd8, 0xa0, 0x02, 0x00, 0x00, 0x00, 0x40, 0x01, 0x00, 0x00, 0x3c, 0x14, 0x24, 0x11,
-	0x80, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x03, 0x7f, 0x07, 0xa0, 0x16,
-	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xd0, 0x9b, 0x38, 0x40, 0x10, 0x28, 0x00, 0x00, 0x00, 0x00,
-	0x64, 0x00, 0x00, 0x05, 0x00, 0x00, 0x01, 0x08, 0x8c, 0x12, 0x98, 0x24, 0xb0, 0x48, 0x60, 0x6c,
-	0x03, 0x01, 0x24, 0x05, 0x04, 0x00, 0x01, 0x00, 0x00, 0x07, 0x2a, 0x55, 0x53, 0x20, 0x24, 0x01,
-	0x11, 0x28, 0x01, 0x11, 0x2c, 0x01, 0x11, 0x30, 0x01, 0x11, 0x34, 0x01, 0x17, 0x38, 0x01, 0x17,
-	0x3c, 0x01, 0x17, 0x40, 0x01, 0x17, 0x95, 0x01, 0x1e, 0x99, 0x01, 0x1e, 0x9d, 0x01, 0x1e, 0xa1,
-	0x01, 0x1e, 0xa5, 0x01, 0x1e, 0x20, 0x01, 0x00, 0xdd, 0x18, 0x00, 0x50, 0xf2, 0x02, 0x01, 0x01,
-	0x00, 0x00, 0x03, 0xa4, 0x00, 0x00, 0x27, 0xa4, 0x00, 0x00, 0x42, 0x43, 0x5e, 0x00, 0x62, 0x32,
-	0x2f, 0x00, 0x34, 0x0c, 0x66, 0x72, 0x65, 0x65, 0x62, 0x73, 0x64, 0x2d, 0x6d, 0x65, 0x73, 0x68,
-	0x33, 0x17, 0x01, 0x00, 0x0f, 0xac, 0x00, 0x00, 0x0f, 0xac, 0x00, 0x00, 0x0f, 0xac, 0xff, 0x00,
-	0x0f, 0xac, 0xff, 0x00, 0x0f, 0xac, 0xff, 0x00, 0xdf,
+	0x00, 0x00, 0x12, 0x00, 0x2e, 0x48, 0x00, 0x00, 0x10, 0x0c, 0x6c, 0x09, 0xc0, 0x00, 0xaf, 0x05,
+	0x00, 0x00, 0x80, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc0, 0x8a, 0xde, 0x01,
+	0x11, 0xb8, 0xc0, 0x8a, 0xde, 0x01, 0x11, 0xb8, 0xf0, 0x97, 0x80, 0xf1, 0x30, 0xbc, 0x13, 0x00,
+	0x00, 0x00, 0x64, 0x00, 0x21, 0x04, 0x00, 0x03, 0x57, 0x69, 0x32, 0x01, 0x08, 0x8c, 0x12, 0x98,
+	0x24, 0xb0, 0x48, 0x60, 0x6c, 0x03, 0x01, 0x01, 0x05, 0x04, 0x00, 0x01, 0x00, 0x00, 0x2a, 0x01,
+	0x00, 0xdd, 0x18, 0x00, 0x50, 0xf2, 0x02, 0x01, 0x01, 0x81, 0x00, 0x07, 0xa4, 0x00, 0x00, 0x23,
+	0xa4, 0x00, 0x00, 0x42, 0x43, 0x5e, 0x00, 0x62, 0x32, 0x2f, 0x00, 0xdd, 0x1e, 0x00, 0x90, 0x4c,
+	0x33, 0x8c, 0x01, 0x1b, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x2d, 0x1a, 0x8c, 0x01, 0x1b,
+	0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xdd, 0x1a, 0x00, 0x90, 0x4c, 0x34, 0x01, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x3d, 0x16, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7f, 0x04, 0x00, 0x00, 0x00,
+	0x00, 0xdd, 0x08, 0x00, 0x13, 0x92, 0x01, 0x00, 0x01, 0x85, 0x00, 0x94, 0x0b, 0x90, 0x15,
 }
 
 func TestPacketDot11MgmtBeacon(t *testing.T) {
 	p := gopacket.NewPacket(testPacketDot11MgmtBeacon, LinkTypeIEEE80211Radio, gopacket.Default)
 	if p.ErrorLayer() != nil {
 		t.Error("Failed to decode packet:", p.ErrorLayer().Error())
 	}
-
-	checkLayers(p, []gopacket.LayerType{LayerTypeRadioTap, LayerTypeDot11, LayerTypeDot11MgmtBeacon}, t)
-
-	if got, ok := p.Layer(LayerTypeRadioTap).(*RadioTap); ok {
-		want := &RadioTap{BaseLayer: BaseLayer{Contents: []uint8{0x0, 0x0, 0x20, 0x0, 0x67, 0x8, 0x4, 0x0, 0xe9, 0xa2, 0xfe, 0x25, 0x0, 0x0, 0x0, 0x0, 0x22, 0xc, 0xd8, 0xa0, 0x2, 0x0, 0x0, 0x0, 0x40, 0x1, 0x0, 0x0, 0x3c, 0x14, 0x24, 0x11}, Payload: []uint8{0x80, 0x0, 0x0, 0x0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x0, 0x3, 0x7f, 0x7, 0xa0, 0x16, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xd0, 0x9b, 0x38, 0x40, 0x10, 0x28, 0x0, 0x0, 0x0, 0x0, 0x64, 0x0, 0x0, 0x5, 0x0, 0x0, 0x1, 0x8, 0x8c, 0x12, 0x98, 0x24, 0xb0, 0x48, 0x60, 0x6c, 0x3, 0x1, 0x24, 0x5, 0x4, 0x0, 0x1, 0x0, 0x0, 0x7, 0x2a, 0x55, 0x53, 0x20, 0x24, 0x1, 0x11, 0x28, 0x1, 0x11, 0x2c, 0x1, 0x11, 0x30, 0x1, 0x11, 0x34, 0x1, 0x17, 0x38, 0x1, 0x17, 0x3c, 0x1, 0x17, 0x40, 0x1, 0x17, 0x95, 0x1, 0x1e, 0x99, 0x1, 0x1e, 0x9d, 0x1, 0x1e, 0xa1, 0x1, 0x1e, 0xa5, 0x1, 0x1e, 0x20, 0x1, 0x0, 0xdd, 0x18, 0x0, 0x50, 0xf2, 0x2, 0x1, 0x1, 0x0, 0x0, 0x3, 0xa4, 0x0, 0x0, 0x27, 0xa4, 0x0, 0x0, 0x42, 0x43, 0x5e, 0x0, 0x62, 0x32, 0x2f, 0x0, 0x34, 0xc, 0x66, 0x72, 0x65, 0x65, 0x62, 0x73, 0x64, 0x2d, 0x6d, 0x65, 0x73, 0x68, 0x33, 0x17, 0x1, 0x0, 0xf, 0xac, 0x0, 0x0, 0xf, 0xac, 0x0, 0x0, 0xf, 0xac, 0xff, 0x0, 0xf, 0xac, 0xff, 0x0, 0xf, 0xac, 0xff, 0x0, 0xdf}}, Version: 0x0, Length: 0x20, Present: 0x40867, TSFT: 0x25fea2e9, Flags: 0x22, Rate: 0xc, ChannelFrequency: 0x0, ChannelFlags: 0x0, FHSS: 0x0, DBMAntennaSignal: -40, DBMAntennaNoise: -96, LockQuality: 0x0, TxAttenuation: 0x0, DBTxAttenuation: 0x0, DBMTxPower: 0, Antenna: 0x2, DBAntennaSignal: 0x0, DBAntennaNoise: 0x0}
-
-		if !reflect.DeepEqual(got, want) {
-			t.Errorf("RadioTap packet processing failed:\ngot  :\n%#v\n\nwant :\n%#v\n\n", got, want)
-		}
+	expectedLayers := []gopacket.LayerType{LayerTypeRadioTap, LayerTypeDot11, LayerTypeDot11MgmtBeacon}
+	for i := 0; i < 12; i++ {
+		expectedLayers = append(expectedLayers, LayerTypeDot11InformationElement)
 	}
+	checkLayers(p, expectedLayers, t)
 
-	if got, ok := p.Layer(LayerTypeDot11).(*Dot11); ok {
-		want := &Dot11{
-			BaseLayer: BaseLayer{
-				Contents: []uint8{0x80, 0x0, 0x0, 0x0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x0, 0x3, 0x7f, 0x7, 0xa0, 0x16, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xd0, 0x9b},
-				Payload:  []uint8{0x38, 0x40, 0x10, 0x28, 0x0, 0x0, 0x0, 0x0, 0x64, 0x0, 0x0, 0x5, 0x0, 0x0, 0x1, 0x8, 0x8c, 0x12, 0x98, 0x24, 0xb0, 0x48, 0x60, 0x6c, 0x3, 0x1, 0x24, 0x5, 0x4, 0x0, 0x1, 0x0, 0x0, 0x7, 0x2a, 0x55, 0x53, 0x20, 0x24, 0x1, 0x11, 0x28, 0x1, 0x11, 0x2c, 0x1, 0x11, 0x30, 0x1, 0x11, 0x34, 0x1, 0x17, 0x38, 0x1, 0x17, 0x3c, 0x1, 0x17, 0x40, 0x1, 0x17, 0x95, 0x1, 0x1e, 0x99, 0x1, 0x1e, 0x9d, 0x1, 0x1e, 0xa1, 0x1, 0x1e, 0xa5, 0x1, 0x1e, 0x20, 0x1, 0x0, 0xdd, 0x18, 0x0, 0x50, 0xf2, 0x2, 0x1, 0x1, 0x0, 0x0, 0x3, 0xa4, 0x0, 0x0, 0x27, 0xa4, 0x0, 0x0, 0x42, 0x43, 0x5e, 0x0, 0x62, 0x32, 0x2f, 0x0, 0x34, 0xc, 0x66, 0x72, 0x65, 0x65, 0x62, 0x73, 0x64, 0x2d, 0x6d, 0x65, 0x73, 0x68, 0x33, 0x17, 0x1, 0x0, 0xf, 0xac, 0x0, 0x0, 0xf, 0xac, 0x0, 0x0, 0xf, 0xac, 0xff, 0x0, 0xf, 0xac, 0xff, 0x0, 0xf},
-			},
-			Type:           Dot11TypeMgmtBeacon,
-			Proto:          0x0,
-			Flags:          0x0,
-			DurationID:     0x0,
-			Address1:       net.HardwareAddr{0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
-			Address2:       net.HardwareAddr{0x0, 0x3, 0x7f, 0x7, 0xa0, 0x16},
-			Address3:       net.HardwareAddr{0x0, 0x0, 0x0, 0x0, 0x0, 0x0},
-			Address4:       net.HardwareAddr(nil),
-			SequenceNumber: 0x26f, FragmentNumber: 0x10,
-			Checksum: 0xdf00ffac,
-		}
-
-		if !reflect.DeepEqual(got, want) {
-			t.Errorf("Dot11 packet processing failed:\ngot  :\n%#v\n\nwant :\n%#v\n\n", got, want)
-		}
+	if _, ok := p.Layer(LayerTypeDot11MgmtBeacon).(*Dot11MgmtBeacon); !ok {
+		t.Errorf("dot11 management beacon frame was expected")
 	}
 }
 
@@ -229,25 +209,17 @@ func BenchmarkDecodePacketDot11DataQOSData(b *testing.B) {
 	}
 }
 
-// this test is failing, this has probably todo with the datapad
-
 // testPacketDot11MgmtAction is the packet:
-//   06:14:23.248019 634199967us tsft short preamble 6.0 Mb/s -41dB signal -96dB noise antenna 1 5180 MHz 11a Action (00:03:7f:07:a0:16): Reserved(32) Act#0
-//   	0x0000:  0000 2000 6708 0400 9f1f cd25 0000 0000  ....g......%....
-//   	0x0010:  220c d7a0 0100 0000 4001 0000 3c14 2411  ".......@...<.$.
-//   	0x0020:  d000 0000 ffff ffff ffff 0003 7f07 a016  ................
-//   	0x0030:  0003 7f07 a016 a002 2000 4425 0001 1e06  ..........D%....
-//   	0x0040:  0000 0000 037f 0342 5206 0000 0088 1300  .......BR.......
-//   	0x0050:  0030 0b00 0001 0600 16cb ace5 f900 0000  .0..............
-//   	0x0060:  00                                       .
+//   15:54:43.236460 1.0 Mb/s 2412 MHz 11b -67dB signal antenna 5 Action (8e:3a:e3:44:ac:c6): Spectrum Management Act#4
+//   	0x0000:  0000 1200 2e48 0000 1002 6c09 a000 bd05  .....H....l.....
+//   	0x0010:  0000 d000 0000 ffff ffff ffff 8e3a e344  .............:.D
+//   	0x0020:  acc6 8e3a e344 acc6 001b 0004 2503 0001  ...:.D......%...
+//   	0x0030:  0055 39f0 33                             .U9.3
 var testPacketDot11MgmtAction = []byte{
-	0x00, 0x00, 0x20, 0x00, 0x67, 0x08, 0x04, 0x00, 0x9f, 0x1f, 0xcd, 0x25, 0x00, 0x00, 0x00, 0x00,
-	0x22, 0x0c, 0xd7, 0xa0, 0x01, 0x00, 0x00, 0x00, 0x40, 0x01, 0x00, 0x00, 0x3c, 0x14, 0x24, 0x11,
-	0xd0, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x03, 0x7f, 0x07, 0xa0, 0x16,
-	0x00, 0x03, 0x7f, 0x07, 0xa0, 0x16, 0xa0, 0x02, 0x20, 0x00, 0x44, 0x25, 0x00, 0x01, 0x1e, 0x06,
-	0x00, 0x00, 0x00, 0x00, 0x03, 0x7f, 0x03, 0x42, 0x52, 0x06, 0x00, 0x00, 0x00, 0x88, 0x13, 0x00,
-	0x00, 0x30, 0x0b, 0x00, 0x00, 0x01, 0x06, 0x00, 0x16, 0xcb, 0xac, 0xe5, 0xf9, 0x00, 0x00, 0x00,
-	0x00,
+	0x00, 0x00, 0x12, 0x00, 0x2e, 0x48, 0x00, 0x00, 0x10, 0x02, 0x6c, 0x09, 0xa0, 0x00, 0xbd, 0x05,
+	0x00, 0x00, 0xd0, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x8e, 0x3a, 0xe3, 0x44,
+	0xac, 0xc6, 0x8e, 0x3a, 0xe3, 0x44, 0xac, 0xc6, 0x00, 0x1b, 0x00, 0x04, 0x25, 0x03, 0x00, 0x01,
+	0x00, 0x55, 0x39, 0xf0, 0x33,
 }
 
 func TestPacketDot11MgmtAction(t *testing.T) {
@@ -256,24 +228,18 @@ func TestPacketDot11MgmtAction(t *testing.T) {
 		t.Error("Failed to decode packet:", p.ErrorLayer().Error())
 	}
 	checkLayers(p, []gopacket.LayerType{LayerTypeRadioTap, LayerTypeDot11, LayerTypeDot11MgmtAction}, t)
-
-	want := `PACKET: 97 bytes
-- Layer 1 (32 bytes) = RadioTap	{Contents=[..32..] Payload=[..65..] Version=0 Length=32 Present=264295 TSFT=634199967 Flags=SHORT-PREAMBLE,DATAPAD Rate=6 Mb/s ChannelFrequency=0 MHz ChannelFlags= FHSS=0 DBMAntennaSignal=-41 DBMAntennaNoise=-96 LockQuality=0 TxAttenuation=0 DBTxAttenuation=0 DBMTxPower=0 Antenna=1 DBAntennaSignal=0 DBAntennaNoise=0}
-- Layer 2 (24 bytes) = Dot11	{Contents=[..24..] Payload=[..37..] Type=MgmtAction Proto=0 Flags= DurationID=0 Address1=ff:ff:ff:ff:ff:ff Address2=00:03:7f:07:a0:16 Address3=00:03:7f:07:a0:16 Address4= SequenceNumber=10 FragmentNumber=32 Checksum=0}
-- Layer 3 (37 bytes) = Dot11MgmtAction	{Contents=[..37..] Payload=[]}
-`
-	if got := p.String(); got != want {
-		t.Errorf("packet string mismatch:\n---got---\n%q\n---want---\n%q", got, want)
+	if got, ok := p.Layer(LayerTypeDot11).(*Dot11); !ok {
+		t.Errorf("dot11 frame was not parsed")
+	} else if !got.ChecksumValid() {
+		t.Errorf("Dot11 packet processing failed: checksum failed")
 	}
-	if _, ok := p.Layer(LayerTypeDot11).(*Dot11); !ok {
-		t.Errorf("could not get Dot11 layer from packet")
-	} else {
-		// See note above:  this checksum fails most likely due to datapad.
-		// wireshark also says this packet is malformed, so I'm not going to waste
-		// too much more time on it.
-		//   if !got.ChecksumValid() { t.Errorf("Dot11 packet processing failed: checksum failed")	}
+	if got, ok := p.Layer(LayerTypeDot11MgmtAction).(*Dot11MgmtAction); !ok {
+		t.Errorf("management action frame was not parsed")
+	} else if got.Contents[0] != 0 {
+		t.Errorf("action category was not spectrum management")
 	}
 }
+
 func BenchmarkDecodePacketDot11MgmtAction(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		gopacket.NewPacket(testPacketDot11MgmtAction, LinkTypeIEEE80211Radio, gopacket.NoCopy)
@@ -287,7 +253,7 @@ func BenchmarkDecodePacketDot11MgmtAction(b *testing.B) {
 //   	0x0020:  d400 0000 0019 e3d3 5352 46e9 7687       ........SRF.v.
 var testPacketDot11CtrlAck = []byte{
 	0x00, 0x00, 0x20, 0x00, 0x67, 0x08, 0x04, 0x00, 0x96, 0xac, 0x12, 0x26, 0x00, 0x00, 0x00, 0x00,
-	0x22, 0x30, 0xd9, 0xa0, 0x02, 0x00, 0x00, 0x00, 0x40, 0x01, 0x00, 0x00, 0x3c, 0x14, 0x24, 0x11,
+	0x32, 0x30, 0xd9, 0xa0, 0x02, 0x00, 0x00, 0x00, 0x40, 0x01, 0x00, 0x00, 0x3c, 0x14, 0x24, 0x11,
 	0xd4, 0x00, 0x00, 0x00, 0x00, 0x19, 0xe3, 0xd3, 0x53, 0x52, 0x46, 0xe9, 0x76, 0x87,
 }
 
@@ -305,6 +271,9 @@ func TestPacketDot11CtrlAck(t *testing.T) {
 	}
 
 	if got, ok := p.Layer(LayerTypeDot11).(*Dot11); ok {
+		if !got.ChecksumValid() {
+			t.Errorf("Dot11 packet processing failed:\nchecksum failed. got  :\n%#v\n\n", got)
+		}
 		want := &Dot11{
 			BaseLayer: BaseLayer{
 				Contents: []uint8{0xd4, 0x0, 0x0, 0x0, 0x0, 0x19, 0xe3, 0xd3, 0x53, 0x52},
@@ -505,13 +474,13 @@ func TestInformationElement(t *testing.T) {
 		221, 5, 1, 2, 3, 4, 5,
 	}
 	pkt := gopacket.NewPacket(bin, LayerTypeDot11InformationElement, gopacket.NoCopy)
-	
+
 	buf := gopacket.NewSerializeBuffer()
 	var sLayers []gopacket.SerializableLayer
-	for _,l := range pkt.Layers() {
+	for _, l := range pkt.Layers() {
 		sLayers = append(sLayers, l.(*Dot11InformationElement))
 	}
-	if err := gopacket.SerializeLayers(buf, gopacket.SerializeOptions{}, sLayers...); err!=nil {
+	if err := gopacket.SerializeLayers(buf, gopacket.SerializeOptions{}, sLayers...); err != nil {
 		t.Error(err.Error())
 	}
 	if !bytes.Equal(bin, buf.Bytes()) {

diff --git a/layers/radiotap.go b/layers/radiotap.go
@@ -11,6 +11,7 @@ import (
 	"encoding/binary"
 	"fmt"
 	"github.com/google/gopacket"
+	"hash/crc32"
 )
 
 // align calculates the number of bytes needed to align with the width
@@ -405,7 +406,15 @@ func (m *RadioTap) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) erro
 		offset += align(offset, 4)
 	}
 
-	m.BaseLayer = BaseLayer{Contents: data[:m.Length], Payload: data[m.Length:]}
+	payload := data[m.Length:]
+	if !m.Flags.FCS() { // Dot11.DecodeFromBytes() expects FCS present
+		fcs := make([]byte, 4)
+		h := crc32.NewIEEE()
+		h.Write(payload)
+		binary.LittleEndian.PutUint32(fcs, h.Sum32())
+		payload = append(payload, fcs...)
+	}
+	m.BaseLayer = BaseLayer{Contents: data[:m.Length], Payload: payload}
 
 	return nil
 }