feat: add SurveyInfo (#94)

client.go

@@ -60,6 +60,9 @@ func (c *Client) StationInfo(ifi *Interface) ([]*StationInfo, error) {
 	return c.c.StationInfo(ifi)
 }
 
+// SurveyInfo retrieves the survey information about a WiFi interface.
+func (c *Client) SurveyInfo(ifi *Interface) ([]*SurveyInfo, error) { return c.c.SurveyInfo(ifi) }
+
 // SetDeadline sets the read and write deadlines associated with the connection.
 func (c *Client) SetDeadline(t time.Time) error {
 	return c.c.SetDeadline(t)

client_linux.go

@@ -195,6 +195,32 @@ func (c *client) StationInfo(ifi *Interface) ([]*StationInfo, error) {
 	return stations, nil
 }
 
+// SurveyInfo requests that nl80211 return a list of survey information for the
+// specified Interface.
+func (c *client) SurveyInfo(ifi *Interface) ([]*SurveyInfo, error) {
+	msgs, err := c.get(
+		unix.NL80211_CMD_GET_SURVEY,
+		netlink.Dump,
+		ifi,
+		func(ae *netlink.AttributeEncoder) {
+			if ifi.HardwareAddr != nil {
+				ae.Bytes(unix.NL80211_ATTR_MAC, ifi.HardwareAddr)
+			}
+		},
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	surveys := make([]*SurveyInfo, len(msgs))
+	for i := range msgs {
+		if surveys[i], err = parseSurveyInfo(msgs[i].Data); err != nil {
+			return nil, err
+		}
+	}
+	return surveys, nil
+}
+
 // SetDeadline sets the read and write deadlines associated with the connection.
 func (c *client) SetDeadline(t time.Time) error {
 	return c.c.SetDeadline(t)
@@ -539,6 +565,66 @@ func parseRateInfo(b []byte) (*rateInfo, error) {
 	return &info, nil
 }
 
+// parseSurveyInfo parses a single SurveyInfo from a byte slice of netlink
+// attributes.
+func parseSurveyInfo(b []byte) (*SurveyInfo, error) {
+	attrs, err := netlink.UnmarshalAttributes(b)
+	if err != nil {
+		return nil, err
+	}
+
+	var info SurveyInfo
+	for _, a := range attrs {
+		switch a.Type {
+		case unix.NL80211_ATTR_SURVEY_INFO:
+			nattrs, err := netlink.UnmarshalAttributes(a.Data)
+			if err != nil {
+				return nil, err
+			}
+
+			if err := (&info).parseAttributes(nattrs); err != nil {
+				return nil, err
+			}
+
+			// Parsed the necessary data.
+			return &info, nil
+		}
+	}
+
+	// No survey info found
+	return nil, os.ErrNotExist
+}
+
+// parseAttributes parses netlink attributes into a SurveyInfo's fields.
+func (s *SurveyInfo) parseAttributes(attrs []netlink.Attribute) error {
+	for _, a := range attrs {
+		switch a.Type {
+		case unix.NL80211_SURVEY_INFO_FREQUENCY:
+			s.Frequency = int(nlenc.Uint32(a.Data))
+		case unix.NL80211_SURVEY_INFO_NOISE:
+			s.Noise = int(int8(a.Data[0]))
+		case unix.NL80211_SURVEY_INFO_IN_USE:
+			s.InUse = true
+		case unix.NL80211_SURVEY_INFO_TIME:
+			s.ChannelTime = time.Duration(nlenc.Uint64(a.Data)) * time.Millisecond
+		case unix.NL80211_SURVEY_INFO_TIME_BUSY:
+			s.ChannelTimeBusy = time.Duration(nlenc.Uint64(a.Data)) * time.Millisecond
+		case unix.NL80211_SURVEY_INFO_TIME_EXT_BUSY:
+			s.ChannelTimeExtBusy = time.Duration(nlenc.Uint64(a.Data)) * time.Millisecond
+		case unix.NL80211_SURVEY_INFO_TIME_BSS_RX:
+			s.ChannelTimeBssRx = time.Duration(nlenc.Uint64(a.Data)) * time.Millisecond
+		case unix.NL80211_SURVEY_INFO_TIME_RX:
+			s.ChannelTimeRx = time.Duration(nlenc.Uint64(a.Data)) * time.Millisecond
+		case unix.NL80211_SURVEY_INFO_TIME_TX:
+			s.ChannelTimeTx = time.Duration(nlenc.Uint64(a.Data)) * time.Millisecond
+		case unix.NL80211_SURVEY_INFO_TIME_SCAN:
+			s.ChannelTimeScan = time.Duration(nlenc.Uint64(a.Data)) * time.Millisecond
+		}
+	}
+
+	return nil
+}
+
 // attrsContain checks if a slice of netlink attributes contains an attribute
 // with the specified type.
 func attrsContain(attrs []netlink.Attribute, typ uint16) bool {

client_linux_integration_test.go

@@ -73,6 +73,11 @@ func execN(t *testing.T, n int, expect []string, worker_id int) {
 				}
 			}
 
+			if _, err := c.SurveyInfo(ifi); err != nil {
+				if !errors.Is(err, os.ErrNotExist) {
+					panicf("[worker_id %d; iteration %d] failed to retrieve survey info for device %s: %v", worker_id, i, ifi.Name, err)
+				}
+			}
 			names[ifi.Name]++
 		}
 	}

client_linux_test.go

@@ -523,6 +523,31 @@ func (s *StationInfo) attributes() []netlink.Attribute {
 	}
 }
 
+func (s *SurveyInfo) attributes() []netlink.Attribute {
+	attributes := []netlink.Attribute{
+		{Type: unix.NL80211_SURVEY_INFO_FREQUENCY, Data: nlenc.Uint32Bytes(uint32(s.Frequency))},
+		{Type: unix.NL80211_SURVEY_INFO_NOISE, Data: []byte{byte(int8(s.Noise))}},
+	}
+	if s.InUse {
+		attributes = append(attributes, netlink.Attribute{Type: unix.NL80211_SURVEY_INFO_IN_USE})
+	}
+	attributes = append(attributes, []netlink.Attribute{
+		{Type: unix.NL80211_SURVEY_INFO_TIME, Data: nlenc.Uint64Bytes(uint64(s.ChannelTime / time.Millisecond))},
+		{Type: unix.NL80211_SURVEY_INFO_TIME_BUSY, Data: nlenc.Uint64Bytes(uint64(s.ChannelTimeBusy / time.Millisecond))},
+		{Type: unix.NL80211_SURVEY_INFO_TIME_EXT_BUSY, Data: nlenc.Uint64Bytes(uint64(s.ChannelTimeExtBusy / time.Millisecond))},
+		{Type: unix.NL80211_SURVEY_INFO_TIME_BSS_RX, Data: nlenc.Uint64Bytes(uint64(s.ChannelTimeBssRx / time.Millisecond))},
+		{Type: unix.NL80211_SURVEY_INFO_TIME_RX, Data: nlenc.Uint64Bytes(uint64(s.ChannelTimeRx / time.Millisecond))},
+		{Type: unix.NL80211_SURVEY_INFO_TIME_TX, Data: nlenc.Uint64Bytes(uint64(s.ChannelTimeTx / time.Millisecond))},
+		{Type: unix.NL80211_SURVEY_INFO_TIME_SCAN, Data: nlenc.Uint64Bytes(uint64(s.ChannelTimeScan / time.Millisecond))},
+	}...)
+	return []netlink.Attribute{
+		{
+			Type: unix.NL80211_ATTR_SURVEY_INFO,
+			Data: mustMarshalAttributes(attributes),
+		},
+	}
+}
+
 func bitrateAttr(bitrate int) uint32 {
 	return uint32(bitrate / 100 / 1000)
 }
@@ -542,6 +567,10 @@ func mustMessages(t *testing.T, command uint8, want interface{}) genltest.Func {
 		for _, x := range xs {
 			as = append(as, x)
 		}
+	case []*SurveyInfo:
+		for _, x := range xs {
+			as = append(as, x)
+		}
 	default:
 		t.Fatalf("cannot make messages for type: %T", xs)
 	}
@@ -606,3 +635,112 @@ func Test_decodeBSSLoadError(t *testing.T) {
 		t.Error("want error on bogus IE with wrong length")
 	}
 }
+
+func TestLinux_clientSurveryInfoMissingAttributeIsNotExist(t *testing.T) {
+	c := testClient(t, func(_ genetlink.Message, _ netlink.Message) ([]genetlink.Message, error) {
+		// One message without station info attribute
+		return []genetlink.Message{{
+			Header: genetlink.Header{
+				Command: unix.NL80211_CMD_GET_SURVEY,
+			},
+			Data: mustMarshalAttributes([]netlink.Attribute{{
+				Type: unix.NL80211_ATTR_IFINDEX,
+				Data: nlenc.Uint32Bytes(1),
+			}}),
+		}}, nil
+	})
+
+	_, err := c.StationInfo(&Interface{
+		Index:        1,
+		HardwareAddr: net.HardwareAddr{0xe, 0xad, 0xbe, 0xef, 0xde, 0xad},
+	})
+	if !os.IsNotExist(err) {
+		t.Fatalf("expected is not exist, got: %v", err)
+	}
+}
+
+func TestLinux_clientSurveyInfoNoMessagesIsNotExist(t *testing.T) {
+	c := testClient(t, func(_ genetlink.Message, _ netlink.Message) ([]genetlink.Message, error) {
+		// No messages about station info at the generic netlink level.
+		// Caller will interpret this as no station info.
+		return nil, io.EOF
+	})
+
+	info, err := c.SurveyInfo(&Interface{
+		Index:        1,
+		HardwareAddr: net.HardwareAddr{0xe, 0xad, 0xbe, 0xef, 0xde, 0xad},
+	})
+	if err != nil {
+		t.Fatalf("undexpected error: %v", err)
+	}
+	if !reflect.DeepEqual(info, []*SurveyInfo{}) {
+		t.Fatalf("expected info to be an empty slice, got %v", info)
+	}
+}
+
+func TestLinux_clientSurveyInfoOK(t *testing.T) {
+	want := []*SurveyInfo{
+		{
+			Frequency:          2412,
+			Noise:              -95,
+			InUse:              true,
+			ChannelTime:        100 * time.Millisecond,
+			ChannelTimeBusy:    50 * time.Millisecond,
+			ChannelTimeExtBusy: 10 * time.Millisecond,
+			ChannelTimeBssRx:   20 * time.Millisecond,
+			ChannelTimeRx:      30 * time.Millisecond,
+			ChannelTimeTx:      40 * time.Millisecond,
+			ChannelTimeScan:    5 * time.Millisecond,
+		},
+		{
+			Frequency:          2437,
+			Noise:              -90,
+			InUse:              false,
+			ChannelTime:        200 * time.Millisecond,
+			ChannelTimeBusy:    100 * time.Millisecond,
+			ChannelTimeExtBusy: 20 * time.Millisecond,
+			ChannelTimeBssRx:   40 * time.Millisecond,
+			ChannelTimeRx:      60 * time.Millisecond,
+			ChannelTimeTx:      80 * time.Millisecond,
+			ChannelTimeScan:    10 * time.Millisecond,
+		},
+	}
+
+	ifi := &Interface{
+		Index:        1,
+		HardwareAddr: net.HardwareAddr{0xe, 0xad, 0xbe, 0xef, 0xde, 0xad},
+	}
+
+	const flags = netlink.Request | netlink.Dump
+
+	msgsFn := mustMessages(t, unix.NL80211_CMD_GET_SURVEY, want)
+
+	c := testClient(t, genltest.CheckRequest(familyID, unix.NL80211_CMD_GET_SURVEY, flags,
+		func(greq genetlink.Message, nreq netlink.Message) ([]genetlink.Message, error) {
+			// Also verify that the correct interface attributes are
+			// present in the request.
+			attrs, err := netlink.UnmarshalAttributes(greq.Data)
+			if err != nil {
+				t.Fatalf("failed to unmarshal attributes: %v", err)
+			}
+
+			if diff := diffNetlinkAttributes(ifi.idAttrs(), attrs); diff != "" {
+				t.Fatalf("unexpected request netlink attributes (-want +got):\n%s", diff)
+			}
+
+			return msgsFn(greq, nreq)
+		},
+	))
+
+	got, err := c.SurveyInfo(ifi)
+	if err != nil {
+		log.Fatalf("unexpected error: %v", err)
+	}
+
+	for i := range want {
+		if !reflect.DeepEqual(want[i], got[i]) {
+			t.Fatalf("unexpected station info:\n- want: %v\n-  got: %v",
+				want[i], got[i])
+		}
+	}
+}

client_others.go

@@ -22,6 +22,7 @@ func (*client) Close() error                                     { return errUni
 func (*client) Interfaces() ([]*Interface, error)                { return nil, errUnimplemented }
 func (*client) BSS(_ *Interface) (*BSS, error)                   { return nil, errUnimplemented }
 func (*client) StationInfo(_ *Interface) ([]*StationInfo, error) { return nil, errUnimplemented }
+func (*client) SurveyInfo(_ *Interface) ([]*SurveyInfo, error)   { return nil, errUnimplemented }
 func (*client) Connect(_ *Interface, _ string) error             { return errUnimplemented }
 func (*client) Disconnect(_ *Interface) error                    { return errUnimplemented }
 func (*client) ConnectWPAPSK(_ *Interface, _, _ string) error    { return errUnimplemented }

wifi.go

@@ -304,3 +304,38 @@ func parseIEs(b []byte) ([]ie, error) {
 
 	return ies, nil
 }
+
+type SurveyInfo struct {
+	// The frequency in MHz of the channel.
+	Frequency int
+
+	// The noise level in dBm.
+	Noise int
+
+	// The time the radio has spent on this channel.
+	ChannelTime time.Duration
+
+	// The time the radio has spent on this channel while it was active.
+	ChannelTimeActive time.Duration
+
+	// The time the radio has spent on this channel while it was busy.
+	ChannelTimeBusy time.Duration
+
+	// The time the radio has spent on this channel while it was busy with external traffic.
+	ChannelTimeExtBusy time.Duration
+
+	// The time the radio has spent on this channel receiving data from a BSS.
+	ChannelTimeBssRx time.Duration
+
+	// The time the radio has spent on this channel receiving data.
+	ChannelTimeRx time.Duration
+
+	// The time the radio has spent on this channel transmitting data.
+	ChannelTimeTx time.Duration
+
+	// The time the radio has spent on this channel while it was scanning.
+	ChannelTimeScan time.Duration
+
+	// Indicates if the channel is currently in use.
+	InUse bool
+}