feat: add channel width to interface info (#118)

Author: berezovskyi-oleksandr

client_linux.go

@@ -575,6 +575,8 @@ func (ifi *Interface) parseAttributes(attrs []netlink.Attribute) error {
 			ifi.Device = int(nlenc.Uint64(a.Data))
 		case unix.NL80211_ATTR_WIPHY_FREQ:
 			ifi.Frequency = int(nlenc.Uint32(a.Data))
+		case unix.NL80211_ATTR_CHANNEL_WIDTH:
+			ifi.ChannelWidth = ChannelWidth(nlenc.Uint32(a.Data))
 		}
 	}
 

client_linux_test.go

@@ -33,6 +33,7 @@ func TestLinux_clientInterfacesOK(t *testing.T) {
 			Device:       1,
 			Type:         InterfaceTypeStation,
 			Frequency:    2412,
+			ChannelWidth: ChannelWidth80,
 		},
 		{
 			HardwareAddr: net.HardwareAddr{0xde, 0xad, 0xbe, 0xef, 0xde, 0xae},
@@ -459,6 +460,7 @@ func (ifi *Interface) attributes() []netlink.Attribute {
 		{Type: unix.NL80211_ATTR_IFTYPE, Data: nlenc.Uint32Bytes(uint32(ifi.Type))},
 		{Type: unix.NL80211_ATTR_WDEV, Data: nlenc.Uint64Bytes(uint64(ifi.Device))},
 		{Type: unix.NL80211_ATTR_WIPHY_FREQ, Data: nlenc.Uint32Bytes(uint32(ifi.Frequency))},
+		{Type: unix.NL80211_ATTR_CHANNEL_WIDTH, Data: nlenc.Uint32Bytes(uint32(ifi.ChannelWidth))},
 	}
 }
 

wifi.go

@@ -121,6 +121,66 @@ func (t InterfaceType) String() string {
 	}
 }
 
+// A ChannelWidth is the width of a WiFi channel.
+//
+// On Linux, ChannelWidth copies the ordering of nl80211's channel width constants.
+// This may not be the case on other operating systems.
+// See: https://github.com/torvalds/linux/blob/v6.17/include/uapi/linux/nl80211.h#L5136-L5177
+type ChannelWidth int
+
+const (
+	ChannelWidth20NoHT ChannelWidth = iota
+	ChannelWidth20
+	ChannelWidth40
+	ChannelWidth80
+	ChannelWidth80P80
+	ChannelWidth160
+	ChannelWidth5
+	ChannelWidth10
+	ChannelWidth1
+	ChannelWidth2
+	ChannelWidth4
+	ChannelWidth8
+	ChannelWidth16
+	ChannelWidth320
+)
+
+// String returns the string representation of an InterfaceType.
+func (t ChannelWidth) String() string {
+	switch t {
+	case ChannelWidth20NoHT:
+		return "20 MHz (no HT)"
+	case ChannelWidth20:
+		return "20 MHz"
+	case ChannelWidth40:
+		return "40 MHz"
+	case ChannelWidth80:
+		return "80 MHz"
+	case ChannelWidth80P80:
+		return "80+80 MHz"
+	case ChannelWidth160:
+		return "160 MHz"
+	case ChannelWidth5:
+		return "5 MHz"
+	case ChannelWidth10:
+		return "10 MHz"
+	case ChannelWidth1:
+		return "1 MHz"
+	case ChannelWidth2:
+		return "2 MHz"
+	case ChannelWidth4:
+		return "4 MHz"
+	case ChannelWidth8:
+		return "8 MHz"
+	case ChannelWidth16:
+		return "16 MHz"
+	case ChannelWidth320:
+		return "320 MHz"
+	default:
+		return fmt.Sprintf("unknown(%d)", t)
+	}
+}
+
 // An Interface is a WiFi network interface.
 type Interface struct {
 	// The index of the interface.
@@ -143,6 +203,9 @@ type Interface struct {
 
 	// The interface's wireless frequency in MHz.
 	Frequency int
+
+	// The interface's wireless channel width.
+	ChannelWidth ChannelWidth
 }
 
 // StationInfo contains statistics about a WiFi interface operating in

wifi_test.go

@@ -76,6 +76,83 @@ func TestInterfaceTypeString(t *testing.T) {
 	}
 }
 
+func TestChannelWidthString(t *testing.T) {
+	tests := []struct {
+		t ChannelWidth
+		s string
+	}{
+		{
+			t: ChannelWidth20NoHT,
+			s: "20 MHz (no HT)",
+		},
+		{
+			t: ChannelWidth20,
+			s: "20 MHz",
+		},
+		{
+			t: ChannelWidth40,
+			s: "40 MHz",
+		},
+		{
+			t: ChannelWidth80,
+			s: "80 MHz",
+		},
+		{
+			t: ChannelWidth80P80,
+			s: "80+80 MHz",
+		},
+		{
+			t: ChannelWidth160,
+			s: "160 MHz",
+		},
+		{
+			t: ChannelWidth5,
+			s: "5 MHz",
+		},
+		{
+			t: ChannelWidth10,
+			s: "10 MHz",
+		},
+		{
+			t: ChannelWidth1,
+			s: "1 MHz",
+		},
+		{
+			t: ChannelWidth2,
+			s: "2 MHz",
+		},
+		{
+			t: ChannelWidth4,
+			s: "4 MHz",
+		},
+		{
+			t: ChannelWidth8,
+			s: "8 MHz",
+		},
+		{
+			t: ChannelWidth16,
+			s: "16 MHz",
+		},
+		{
+			t: ChannelWidth320,
+			s: "320 MHz",
+		},
+		{
+			t: ChannelWidth320 + 1,
+			s: "unknown(14)",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.s, func(t *testing.T) {
+			if want, got := tt.s, tt.t.String(); want != got {
+				t.Fatalf("unexpected channel width string:\n- want: %q\n-  got: %q",
+					want, got)
+			}
+		})
+	}
+}
+
 func TestBSSStatusString(t *testing.T) {
 	tests := []struct {
 		t BSSStatus