Merge pull request #425 from mdlayher/wifi-update

Update vendored wifi, handle stations with missing info

collector/wifi_linux.go

@@ -155,12 +155,6 @@ func (c *wifiCollector) Update(ch chan<- prometheus.Metric) error {
 			continue
 		}
 
-		info, err := stat.StationInfo(ifi)
-		if err != nil {
-			return fmt.Errorf("failed to retrieve station info for device %s: %v",
-				ifi.Name, err)
-		}
-
 		ch <- prometheus.MustNewConstMetric(
 			c.InterfaceFrequencyHertz,
 			prometheus.GaugeValue,
@@ -168,6 +162,16 @@ func (c *wifiCollector) Update(ch chan<- prometheus.Metric) error {
 			ifi.Name,
 		)
 
+		info, err := stat.StationInfo(ifi)
+		if err != nil {
+			if os.IsNotExist(err) {
+				continue
+			}
+
+			return fmt.Errorf("failed to retrieve station info for device %s: %v",
+				ifi.Name, err)
+		}
+
 		c.updateStationStats(ch, ifi.Name, info)
 	}
 

vendor/github.com/mdlayher/wifi/client.go

@@ -2,12 +2,19 @@ package wifi
 
 import (
 	"errors"
+	"fmt"
+	"runtime"
 )
 
 var (
 	// errNotStation is returned when attempting to query station info for
 	// an interface which is not a station.
 	errNotStation = errors.New("interface is not a station")
+
+	// errUnimplemented is returned by all functions on platforms that
+	// do not have package wifi implemented.
+	errUnimplemented = fmt.Errorf("package wifi not implemented on %s/%s",
+		runtime.GOOS, runtime.GOARCH)
 )
 
 // A Client is a type which can access WiFi device actions and statistics
@@ -38,6 +45,11 @@ func (c *Client) Interfaces() ([]*Interface, error) {
 	return c.c.Interfaces()
 }
 
+// BSS retrieves the BSS associated with a WiFi interface.
+func (c *Client) BSS(ifi *Interface) (*BSS, error) {
+	return c.c.BSS(ifi)
+}
+
 // StationInfo retrieves statistics about a WiFi interface operating in
 // station mode.
 func (c *Client) StationInfo(ifi *Interface) (*StationInfo, error) {
@@ -52,5 +64,6 @@ func (c *Client) StationInfo(ifi *Interface) (*StationInfo, error) {
 type osClient interface {
 	Close() error
 	Interfaces() ([]*Interface, error)
+	BSS(ifi *Interface) (*BSS, error)
 	StationInfo(ifi *Interface) (*StationInfo, error)
 }

vendor/github.com/mdlayher/wifi/client_linux.go

@@ -3,11 +3,13 @@
 package wifi
 
 import (
+	"bytes"
 	"errors"
 	"math"
 	"net"
 	"os"
 	"time"
+	"unicode/utf8"
 
 	"github.com/mdlayher/netlink"
 	"github.com/mdlayher/netlink/genetlink"
@@ -96,10 +98,40 @@ func (c *client) Interfaces() ([]*Interface, error) {
 	return parseInterfaces(msgs)
 }
 
+// BSS requests that nl80211 return the BSS for the specified Interface.
+func (c *client) BSS(ifi *Interface) (*BSS, error) {
+	b, err := netlink.MarshalAttributes(ifi.idAttrs())
+	if err != nil {
+		return nil, err
+	}
+
+	// Ask nl80211 to retrieve BSS information for the interface specified
+	// by its attributes
+	req := genetlink.Message{
+		Header: genetlink.Header{
+			Command: nl80211.CmdGetScan,
+			Version: c.familyVersion,
+		},
+		Data: b,
+	}
+
+	flags := netlink.HeaderFlagsRequest | netlink.HeaderFlagsDump
+	msgs, err := c.c.Execute(req, c.familyID, flags)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := c.checkMessages(msgs, nl80211.CmdNewScanResults); err != nil {
+		return nil, err
+	}
+
+	return parseBSS(msgs)
+}
+
 // StationInfo requests that nl80211 return station info for the specified
 // Interface.
 func (c *client) StationInfo(ifi *Interface) (*StationInfo, error) {
-	b, err := netlink.MarshalAttributes(ifi.stationInfoAttrs())
+	b, err := netlink.MarshalAttributes(ifi.idAttrs())
 	if err != nil {
 		return nil, err
 	}
@@ -176,9 +208,9 @@ func parseInterfaces(msgs []genetlink.Message) ([]*Interface, error) {
 	return ifis, nil
 }
 
-// stationInfoAttrs returns the netlink attributes required from an Interface
-// to retrieve a StationInfo.
-func (ifi *Interface) stationInfoAttrs() []netlink.Attribute {
+// idAttrs returns the netlink attributes required from an Interface to retrieve
+// more data about it.
+func (ifi *Interface) idAttrs() []netlink.Attribute {
 	return []netlink.Attribute{
 		{
 			Type: nl80211.AttrIfindex,
@@ -217,6 +249,80 @@ func (ifi *Interface) parseAttributes(attrs []netlink.Attribute) error {
 	return nil
 }
 
+// parseBSS parses a single BSS with a status attribute from nl80211 BSS messages.
+func parseBSS(msgs []genetlink.Message) (*BSS, error) {
+	for _, m := range msgs {
+		attrs, err := netlink.UnmarshalAttributes(m.Data)
+		if err != nil {
+			return nil, err
+		}
+
+		for _, a := range attrs {
+			if a.Type != nl80211.AttrBss {
+				continue
+			}
+
+			nattrs, err := netlink.UnmarshalAttributes(a.Data)
+			if err != nil {
+				return nil, err
+			}
+
+			// The BSS which is associated with an interface will have a status
+			// attribute
+			if !attrsContain(nattrs, nl80211.BssStatus) {
+				continue
+			}
+
+			var bss BSS
+			if err := (&bss).parseAttributes(nattrs); err != nil {
+				return nil, err
+			}
+
+			return &bss, nil
+		}
+	}
+
+	return nil, os.ErrNotExist
+}
+
+// parseAttributes parses netlink attributes into a BSS's fields.
+func (b *BSS) parseAttributes(attrs []netlink.Attribute) error {
+	for _, a := range attrs {
+		switch a.Type {
+		case nl80211.BssBssid:
+			b.BSSID = net.HardwareAddr(a.Data)
+		case nl80211.BssFrequency:
+			b.Frequency = int(nlenc.Uint32(a.Data))
+		case nl80211.BssBeaconInterval:
+			// Raw value is in "Time Units (TU)".  See:
+			// https://en.wikipedia.org/wiki/Beacon_frame
+			b.BeaconInterval = time.Duration(nlenc.Uint16(a.Data)) * 1024 * time.Microsecond
+		case nl80211.BssSeenMsAgo:
+			// * @NL80211_BSS_SEEN_MS_AGO: age of this BSS entry in ms
+			b.LastSeen = time.Duration(nlenc.Uint32(a.Data)) * time.Millisecond
+		case nl80211.BssStatus:
+			// NOTE: BSSStatus copies the ordering of nl80211's BSS status
+			// constants.  This may not be the case on other operating systems.
+			b.Status = BSSStatus(nlenc.Uint32(a.Data))
+		case nl80211.BssInformationElements:
+			ies, err := parseIEs(a.Data)
+			if err != nil {
+				return err
+			}
+
+			// TODO(mdlayher): return more IEs if they end up being generally useful
+			for _, ie := range ies {
+				switch ie.ID {
+				case ieSSID:
+					b.SSID = decodeSSID(ie.Data)
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
 // parseStationInfo parses StationInfo attributes from a byte slice of
 // netlink attributes.
 func parseStationInfo(b []byte) (*StationInfo, error) {
@@ -262,23 +368,23 @@ func (info *StationInfo) parseAttributes(attrs []netlink.Attribute) error {
 			// * @NL80211_STA_INFO_INACTIVE_TIME: time since last activity (u32, msecs)
 			info.Inactive = time.Duration(nlenc.Uint32(a.Data)) * time.Millisecond
 		case nl80211.StaInfoRxBytes64:
-			info.ReceivedBytes = nlenc.Uint64(a.Data)
+			info.ReceivedBytes = int(nlenc.Uint64(a.Data))
 		case nl80211.StaInfoTxBytes64:
-			info.TransmittedBytes = nlenc.Uint64(a.Data)
+			info.TransmittedBytes = int(nlenc.Uint64(a.Data))
 		case nl80211.StaInfoSignal:
 			// Converted into the typical negative strength format
 			//  * @NL80211_STA_INFO_SIGNAL: signal strength of last received PPDU (u8, dBm)
 			info.Signal = int(a.Data[0]) - math.MaxUint8
 		case nl80211.StaInfoRxPackets:
-			info.ReceivedPackets = nlenc.Uint32(a.Data)
+			info.ReceivedPackets = int(nlenc.Uint32(a.Data))
 		case nl80211.StaInfoTxPackets:
-			info.TransmittedPackets = nlenc.Uint32(a.Data)
+			info.TransmittedPackets = int(nlenc.Uint32(a.Data))
 		case nl80211.StaInfoTxRetries:
-			info.TransmitRetries = nlenc.Uint32(a.Data)
+			info.TransmitRetries = int(nlenc.Uint32(a.Data))
 		case nl80211.StaInfoTxFailed:
-			info.TransmitFailed = nlenc.Uint32(a.Data)
+			info.TransmitFailed = int(nlenc.Uint32(a.Data))
 		case nl80211.StaInfoBeaconLoss:
-			info.BeaconLoss = nlenc.Uint32(a.Data)
+			info.BeaconLoss = int(nlenc.Uint32(a.Data))
 		case nl80211.StaInfoRxBitrate, nl80211.StaInfoTxBitrate:
 			rate, err := parseRateInfo(a.Data)
 			if err != nil {
@@ -299,10 +405,10 @@ func (info *StationInfo) parseAttributes(attrs []netlink.Attribute) error {
 		// If the 64-bit counters appear later in the slice, they will overwrite
 		// these values.
 		if info.ReceivedBytes == 0 && a.Type == nl80211.StaInfoRxBytes {
-			info.ReceivedBytes = uint64(nlenc.Uint32(a.Data))
+			info.ReceivedBytes = int(nlenc.Uint32(a.Data))
 		}
 		if info.TransmittedBytes == 0 && a.Type == nl80211.StaInfoTxBytes {
-			info.TransmittedBytes = uint64(nlenc.Uint32(a.Data))
+			info.TransmittedBytes = int(nlenc.Uint32(a.Data))
 		}
 	}
 
@@ -345,6 +451,32 @@ func parseRateInfo(b []byte) (*rateInfo, error) {
 	return &info, nil
 }
 
+// attrsContain checks if a slice of netlink attributes contains an attribute
+// with the specified type.
+func attrsContain(attrs []netlink.Attribute, typ uint16) bool {
+	for _, a := range attrs {
+		if a.Type == typ {
+			return true
+		}
+	}
+
+	return false
+}
+
+// decodeSSID safely parses a byte slice into UTF-8 runes, and returns the
+// resulting string from the runes.
+func decodeSSID(b []byte) string {
+	buf := bytes.NewBuffer(nil)
+	for len(b) > 0 {
+		r, size := utf8.DecodeRune(b)
+		b = b[size:]
+
+		buf.WriteRune(r)
+	}
+
+	return buf.String()
+}
+
 var _ genl = &sysGENL{}
 
 // sysGENL is the system implementation of genl, using generic netlink.

vendor/github.com/mdlayher/wifi/client_others.go

@@ -2,18 +2,6 @@
 
 package wifi
 
-import (
-	"fmt"
-	"runtime"
-)
-
-var (
-	// errUnimplemented is returned by all functions on platforms that
-	// do not have package wifi implemented.
-	errUnimplemented = fmt.Errorf("package wifi not implemented on %s/%s",
-		runtime.GOOS, runtime.GOARCH)
-)
-
 var _ osClient = &client{}
 
 // A conn is the no-op implementation of a netlink sockets connection.
@@ -34,6 +22,11 @@ func (c *client) Interfaces() ([]*Interface, error) {
 	return nil, errUnimplemented
 }
 
+// BSS always returns an error.
+func (c *client) BSS(ifi *Interface) (*BSS, error) {
+	return nil, errUnimplemented
+}
+
 // StationInfo always returns an error.
 func (c *client) StationInfo(ifi *Interface) (*StationInfo, error) {
 	return nil, errUnimplemented

vendor/github.com/mdlayher/wifi/wifi.go

@@ -1,10 +1,17 @@
 package wifi
 
 import (
+	"errors"
+	"fmt"
 	"net"
 	"time"
 )
 
+var (
+	// errInvalidIE is returned when one or more IEs are malformed.
+	errInvalidIE = errors.New("invalid 802.11 information element")
+)
+
 // An InterfaceType is the operating mode of an Interface.
 type InterfaceType int
 
@@ -96,16 +103,16 @@ type StationInfo struct {
 	Inactive time.Duration
 
 	// The number of bytes received by this station.
-	ReceivedBytes uint64
+	ReceivedBytes int
 
 	// The number of bytes transmitted by this station.
-	TransmittedBytes uint64
+	TransmittedBytes int
 
 	// The number of packets received by this station.
-	ReceivedPackets uint32
+	ReceivedPackets int
 
 	// The number of packets transmitted by this station.
-	TransmittedPackets uint32
+	TransmittedPackets int
 
 	// The current data receive bitrate, in bits/second.
 	ReceiveBitrate int
@@ -117,11 +124,109 @@ type StationInfo struct {
 	Signal int
 
 	// The number of times the station has had to retry while sending a packet.
-	TransmitRetries uint32
+	TransmitRetries int
 
 	// The number of times a packet transmission failed.
-	TransmitFailed uint32
+	TransmitFailed int
 
 	// The number of times a beacon loss was detected.
-	BeaconLoss uint32
+	BeaconLoss int
+}
+
+// A BSS is an 802.11 basic service set.  It contains information about a wireless
+// network associated with an Interface.
+type BSS struct {
+	// The service set identifier, or "network name" of the BSS.
+	SSID string
+
+	// The BSS service set identifier.  In infrastructure mode, this is the
+	// hardware address of the wireless access point that a client is associated
+	// with.
+	BSSID net.HardwareAddr
+
+	// The frequency used by the BSS, in MHz.
+	Frequency int
+
+	// The interval between beacon transmissions for this BSS.
+	BeaconInterval time.Duration
+
+	// The time since the client last scanned this BSS's information.
+	LastSeen time.Duration
+
+	// The status of the client within the BSS.
+	Status BSSStatus
+}
+
+// A BSSStatus indicates the current status of client within a BSS.
+type BSSStatus int
+
+const (
+	// BSSStatusAuthenticated indicates that a client is authenticated with a BSS.
+	BSSStatusAuthenticated BSSStatus = iota
+
+	// BSSStatusAssociated indicates that a client is associated with a BSS.
+	BSSStatusAssociated
+
+	// BSSStatusIBSSJoined indicates that a client has joined an independent BSS.
+	BSSStatusIBSSJoined
+)
+
+// String returns the string representation of a BSSStatus.
+func (s BSSStatus) String() string {
+	switch s {
+	case BSSStatusAuthenticated:
+		return "authenticated"
+	case BSSStatusAssociated:
+		return "associated"
+	case BSSStatusIBSSJoined:
+		return "IBSS joined"
+	default:
+		return fmt.Sprintf("unknown(%d)", s)
+	}
+}
+
+// List of 802.11 Information Element types.
+const (
+	ieSSID = 0
+)
+
+// An ie is an 802.11 information element.
+type ie struct {
+	ID uint8
+	// Length field implied by length of data
+	Data []byte
+}
+
+// parseIEs parses zero or more ies from a byte slice.
+// Reference:
+//   https://www.safaribooksonline.com/library/view/80211-wireless-networks/0596100523/ch04.html#wireless802dot112-CHP-4-FIG-31
+func parseIEs(b []byte) ([]ie, error) {
+	var ies []ie
+	var i int
+	for {
+		if len(b[i:]) == 0 {
+			break
+		}
+		if len(b[i:]) < 2 {
+			return nil, errInvalidIE
+		}
+
+		id := b[i]
+		i++
+		l := int(b[i])
+		i++
+
+		if len(b[i:]) < l {
+			return nil, errInvalidIE
+		}
+
+		ies = append(ies, ie{
+			ID:   id,
+			Data: b[i : i+l],
+		})
+
+		i += l
+	}
+
+	return ies, nil
 }

vendor/vendor.json

@@ -69,10 +69,10 @@
 			"revisionTime": "2017-01-04T04:59:06Z"
 		},
 		{
-			"checksumSHA1": "l8M/rZH5s/ZVtCCyeiUQXZ5FosA=",
+			"checksumSHA1": "J6L0K9aHO8riicB4BY8/WHb6wBI=",
 			"path": "github.com/mdlayher/wifi",
-			"revision": "eb8b29b956ba5ff2fdd2d2f1f0b988b57fd3d8a3",
-			"revisionTime": "2017-01-12T20:47:29Z"
+			"revision": "85a20a7adc659e5007fb9dd0961ba4e8b7ea2f80",
+			"revisionTime": "2017-01-17T05:43:47Z"
 		},
 		{
 			"checksumSHA1": "VzutdH69PUqRqhrDVv6F91ebQd4=",