Improve windows kext bandwidth stats monitor

firewall/interception/windowskext/bandwidth_stats.go

@@ -6,9 +6,11 @@ package windowskext
 // This file contains example code how to read bandwidth stats from the kext. Its not ment to be used in production.
 
 import (
+	"context"
 	"time"
 
 	"github.com/safing/portbase/log"
+	"github.com/safing/portmaster/network/packet"
 )
 
 type Rxtxdata struct {
@@ -27,7 +29,56 @@ type Key struct {
 
 var m = make(map[Key]Rxtxdata)
 
-func StartBandwidthWorker() {
+func BandwidthStatsWorker(ctx context.Context, collectInterval time.Duration, bandwidthUpdates chan *packet.BandwidthUpdate) error {
+	// Setup ticker.
+	ticker := time.NewTicker(collectInterval)
+	defer ticker.Stop()
+
+	// Collect bandwidth at every tick.
+	for {
+		select {
+		case <-ticker.C:
+			err := reportBandwidth(ctx, bandwidthUpdates)
+			if err != nil {
+				return err
+			}
+		case <-ctx.Done():
+			return nil
+		}
+	}
+}
+
+func reportBandwidth(ctx context.Context, bandwidthUpdates chan *packet.BandwidthUpdate) error {
+	stats, err := GetConnectionsStats()
+	if err != nil {
+		return err
+	}
+
+	// Report all statistics.
+	for _, stat := range stats {
+		connID := packet.CreateConnectionID(
+			packet.IPProtocol(stat.protocol),
+			convertArrayToIP(stat.localIP, stat.ipV6 == 1), stat.localPort,
+			convertArrayToIP(stat.remoteIP, stat.ipV6 == 1), stat.remotePort,
+			false,
+		)
+		update := &packet.BandwidthUpdate{
+			ConnID:    connID,
+			RecvBytes: stat.receivedBytes,
+			SentBytes: stat.transmittedBytes,
+			Method:    packet.Additive,
+		}
+		select {
+		case bandwidthUpdates <- update:
+		case <-ctx.Done():
+			return nil
+		}
+	}
+
+	return nil
+}
+
+func StartBandwithConsoleLogger() {
 	go func() {
 		ticker := time.NewTicker(2 * time.Second)
 		defer ticker.Stop()
@@ -66,14 +117,13 @@ func StartBandwidthWorker() {
 			}
 			log.Debug("----------------------------------")
 			for key, value := range m {
-				if key.ipv6 {
-					log.Debugf("Conn: %d %s:%d %s:%d rx:%d tx:%d", key.protocol, convertIPv6(key.localIP), key.localPort, convertIPv6(key.remoteIP), key.remotePort, value.rx, value.tx)
-				} else {
-					log.Debugf("Conn: %d %s:%d %s:%d rx:%d tx:%d", key.protocol, convertIPv4(key.localIP), key.localPort, convertIPv4(key.remoteIP), key.remotePort, value.rx, value.tx)
-				}
-
+				log.Debugf(
+					"Conn: %d %s:%d %s:%d rx:%d tx:%d", key.protocol,
+					convertArrayToIP(key.localIP, key.ipv6), key.localPort,
+					convertArrayToIP(key.remoteIP, key.ipv6), key.remotePort,
+					value.rx, value.tx,
+				)
 			}
-
 		}
 	}()
 }

firewall/interception/windowskext/handler.go

@@ -4,6 +4,7 @@
 package windowskext
 
 import (
+	"context"
 	"encoding/binary"
 	"errors"
 	"fmt"
@@ -96,9 +97,7 @@ func (v *VersionInfo) String() string {
 }
 
 // Handler transforms received packets to the Packet interface.
-func Handler(packets chan packet.Packet) {
-	defer close(packets)
-
+func Handler(ctx context.Context, packets chan packet.Packet) {
 	for {
 		packetInfo, err := RecvVerdictRequest()
 		if err != nil {
@@ -144,28 +143,14 @@ func Handler(packets chan packet.Packet) {
 		}
 
 		// Set IPs
-		if info.Version == packet.IPv4 {
-			// IPv4
-			if info.Inbound {
-				// Inbound
-				info.Src = convertIPv4(packetInfo.remoteIP)
-				info.Dst = convertIPv4(packetInfo.localIP)
-			} else {
-				// Outbound
-				info.Src = convertIPv4(packetInfo.localIP)
-				info.Dst = convertIPv4(packetInfo.remoteIP)
-			}
+		if info.Inbound {
+			// Inbound
+			info.Src = convertArrayToIP(packetInfo.remoteIP, info.Version == packet.IPv6)
+			info.Dst = convertArrayToIP(packetInfo.localIP, info.Version == packet.IPv6)
 		} else {
-			// IPv6
-			if info.Inbound {
-				// Inbound
-				info.Src = convertIPv6(packetInfo.remoteIP)
-				info.Dst = convertIPv6(packetInfo.localIP)
-			} else {
-				// Outbound
-				info.Src = convertIPv6(packetInfo.localIP)
-				info.Dst = convertIPv6(packetInfo.remoteIP)
-			}
+			// Outbound
+			info.Src = convertArrayToIP(packetInfo.localIP, info.Version == packet.IPv6)
+			info.Dst = convertArrayToIP(packetInfo.remoteIP, info.Version == packet.IPv6)
 		}
 
 		// Set Ports
@@ -183,14 +168,14 @@ func Handler(packets chan packet.Packet) {
 	}
 }
 
-// convertIPv4 as needed for data from the kernel
-func convertIPv4(input [4]uint32) net.IP {
-	addressBuf := make([]byte, 4)
-	binary.BigEndian.PutUint32(addressBuf, input[0])
-	return net.IP(addressBuf)
-}
+// convertArrayToIP converts an array of uint32 values to a net.IP address.
+func convertArrayToIP(input [4]uint32, ipv6 bool) net.IP {
+	if !ipv6 {
+		addressBuf := make([]byte, 4)
+		binary.BigEndian.PutUint32(addressBuf, input[0])
+		return net.IP(addressBuf)
+	}
 
-func convertIPv6(input [4]uint32) net.IP {
 	addressBuf := make([]byte, 16)
 	for i := 0; i < 4; i++ {
 		binary.BigEndian.PutUint32(addressBuf[i*4:i*4+4], input[i])

firewall/interception/windowskext/kext.go

@@ -8,7 +8,6 @@ import (
 	"fmt"
 	"sync"
 	"syscall"
-	"time"
 	"unsafe"
 
 	"github.com/safing/portbase/log"
@@ -290,6 +289,8 @@ func GetVersion() (*VersionInfo, error) {
 	return version, nil
 }
 
+var sizeOfConnectionStat = uint32(unsafe.Sizeof(ConnectionStat{}))
+
 func GetConnectionsStats() ([]ConnectionStat, error) {
 	kextLock.RLock()
 	defer kextLock.RUnlock()
@@ -302,12 +303,13 @@ func GetConnectionsStats() ([]ConnectionStat, error) {
 
 	var data [100]ConnectionStat
 	size := len(data)
-	_, err := deviceIOControl(kextHandle, IOCTL_GET_CONNECTIONS_STAT, asByteArray(&size), asByteArray(&data))
+	bytesReturned, err := deviceIOControl(kextHandle, IOCTL_GET_CONNECTIONS_STAT, asByteArray(&size), asByteArray(&data))
 
 	if err != nil {
 		return nil, err
 	}
-	return data[:], nil
+
+	return data[:bytesReturned/sizeOfConnectionStat], nil
 }
 
 func openDriver(filename string) (windows.Handle, error) {