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Removed legacy code and refactoring

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This commit is contained in:
Vladimir
2022-11-07 11:07:49 +01:00
parent 1b480066be
commit 3768db6b32
4 changed files with 157 additions and 145 deletions
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116
firewall/interception/windowskext/kext.go
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@@ -6,15 +6,13 @@ package windowskext
import (
"errors"
"fmt"
"os/exec"
"sync"
"sync/atomic"
"syscall"
"time"
"unsafe"
"github.com/safing/portbase/log"
"github.com/safing/portmaster/network"
"github.com/tevino/abool"
"golang.org/x/sys/windows"
)
@@ -23,25 +21,22 @@ var (
ErrKextNotReady = errors.New("the windows kernel extension (driver) is not ready to accept commands")
ErrNoPacketID = errors.New("the packet has no ID, possibly because it was fast-tracked by the kernel extension")
winErrInvalidData = uintptr(windows.ERROR_INVALID_DATA)
kextLock sync.RWMutex
ready = abool.NewBool(false)
urgentRequests *int32
driverPath string
kextLock sync.RWMutex
driverPath string
kextHandle windows.Handle
service *KextService
)
const driverName = "PortmasterKext"
func init() {
var urgentRequestsValue int32
urgentRequests = &urgentRequestsValue
}
const (
winErrInvalidData = uintptr(windows.ERROR_INVALID_DATA)
winInvalidHandleValue = windows.Handle(^uintptr(0)) // Max value
driverName = "PortmasterKext"
)
// Init initializes the DLL and the Kext (Kernel Driver).
func Init(path string) error {
kextHandle = winInvalidHandleValue
driverPath = path
return nil
}
@@ -61,24 +56,25 @@ func Start() error {
}
// initialize and start driver service
service, err := driverInstall(driverPath)
service, err = createKextService(driverName, driverPath)
if err != nil {
return fmt.Errorf("Failed to start service: %s", err)
return fmt.Errorf("failed to create service: %w", err)
}
err = service.start()
if err != nil {
return fmt.Errorf("failed to start service: %w", err)
}
// open the driver
kextHandle, err = openDriver(filename)
// close the service handles
_ = windows.DeleteService(service)
_ = windows.CloseServiceHandle(service)
// driver was not installed
if err != nil {
return fmt.Errorf("Failed to start the kext service: %s %q", err, filename)
return fmt.Errorf("failed to open driver: %q %w", filename, err)
}
ready.Set()
return nil
}
@@ -86,20 +82,27 @@ func Start() error {
func Stop() error {
kextLock.Lock()
defer kextLock.Unlock()
if !ready.IsSet() {
return ErrKextNotReady
}
ready.UnSet()
err := closeDriver(kextHandle)
if err != nil {
log.Errorf("winkext: failed to close the handle: %s", err)
log.Warningf("winkext: failed to close the handle: %s", err)
}
_, err = exec.Command("sc", "stop", driverName).Output() // This is a question of taste, but it is a robust and solid solution
err = service.stop()
if err != nil {
log.Errorf("winkext: failed to stop the service: %q", err)
log.Warningf("winkext: failed to stop service: %s", err)
}
// Driver file may change on the next start so it's better to delete the service
err = service.delete()
if err != nil {
log.Warningf("winkext: failed to delete service: %s", err)
}
err = service.closeHandle()
if err != nil {
log.Warningf("winkext: failed to close the handle: %s", err)
}
kextHandle = winInvalidHandleValue
return nil
}
@@ -107,19 +110,9 @@ func Stop() error {
func RecvVerdictRequest() (*VerdictRequest, error) {
kextLock.RLock()
defer kextLock.RUnlock()
if !ready.IsSet() {
if kextHandle == winInvalidHandleValue {
return nil, ErrKextNotReady
}
// wait for urgent requests to complete
for i := 1; i <= 100; i++ {
if atomic.LoadInt32(urgentRequests) <= 0 {
break
}
if i == 100 {
log.Warningf("winkext: RecvVerdictRequest waited 100 times")
}
time.Sleep(100 * time.Microsecond)
}
timestamp := time.Now()
// Initialize struct for the output data
@@ -127,7 +120,7 @@ func RecvVerdictRequest() (*VerdictRequest, error) {
// Make driver request
data := asByteArray(&new)
bytesRead, err := deviceIoControlRead(kextHandle, IOCTL_RECV_VERDICT_REQ, data)
bytesRead, err := deviceIOControl(kextHandle, IOCTL_RECV_VERDICT_REQ, nil, data)
if err != nil {
return nil, err
}
@@ -148,7 +141,7 @@ func SetVerdict(pkt *Packet, verdict network.Verdict) error {
kextLock.RLock()
defer kextLock.RUnlock()
if !ready.IsSet() {
if kextHandle == winInvalidHandleValue {
log.Tracer(pkt.Ctx()).Errorf("kext: failed to set verdict %s: kext not ready", verdict)
return ErrKextNotReady
}
@@ -156,10 +149,8 @@ func SetVerdict(pkt *Packet, verdict network.Verdict) error {
verdictInfo := VerdictInfo{pkt.verdictRequest.id, verdict}
// Make driver request
atomic.AddInt32(urgentRequests, 1)
data := asByteArray(&verdictInfo)
_, err := deviceIoControlWrite(kextHandle, IOCTL_SET_VERDICT, data)
atomic.AddInt32(urgentRequests, -1)
_, err := deviceIOControl(kextHandle, IOCTL_SET_VERDICT, data, nil)
if err != nil {
log.Tracer(pkt.Ctx()).Errorf("kext: failed to set verdict %s on packet %d", verdict, pkt.verdictRequest.id)
return err
@@ -176,7 +167,7 @@ func GetPayload(packetID uint32, packetSize uint32) ([]byte, error) {
// Check if driver is initialized
kextLock.RLock()
defer kextLock.RUnlock()
if !ready.IsSet() {
if kextHandle == winInvalidHandleValue {
return nil, ErrKextNotReady
}
@@ -189,11 +180,8 @@ func GetPayload(packetID uint32, packetSize uint32) ([]byte, error) {
}{packetID, packetSize}
// Make driver request
atomic.AddInt32(urgentRequests, 1)
data := asByteArray(&payload)
bytesRead, err := deviceIoControlReadWrite(kextHandle, IOCTL_GET_PAYLOAD, data, unsafe.Slice(&buf[0], packetSize))
atomic.AddInt32(urgentRequests, -1)
bytesRead, err := deviceIOControl(kextHandle, IOCTL_GET_PAYLOAD, data, unsafe.Slice(&buf[0], packetSize))
if err != nil {
return nil, err
@@ -216,16 +204,38 @@ func ClearCache() error {
defer kextLock.RUnlock()
// Check if driver is initialized
if !ready.IsSet() {
if kextHandle == winInvalidHandleValue {
log.Error("kext: failed to clear the cache: kext not ready")
return ErrKextNotReady
}
// Make driver request
_, err := deviceIoControlRead(kextHandle, IOCTL_CLEAR_CACHE, nil)
_, err := deviceIOControl(kextHandle, IOCTL_CLEAR_CACHE, nil, nil)
return err
}
func asByteArray[T any](obj *T) []byte {
return unsafe.Slice((*byte)(unsafe.Pointer(obj)), unsafe.Sizeof(*obj))
}
func openDriver(filename string) (windows.Handle, error) {
u16filename, err := syscall.UTF16FromString(filename)
if err != nil {
return winInvalidHandleValue, fmt.Errorf("failed to convert driver filename to UTF16 string %w", err)
}
handle, err := windows.CreateFile(&u16filename[0], windows.GENERIC_READ|windows.GENERIC_WRITE, 0, nil, windows.OPEN_EXISTING, windows.FILE_ATTRIBUTE_NORMAL|windows.FILE_FLAG_OVERLAPPED, 0)
if err != nil {
return winInvalidHandleValue, err
}
return handle, nil
}
func closeDriver(handle windows.Handle) error {
if kextHandle == winInvalidHandleValue {
return ErrKextNotReady
}
return windows.CloseHandle(handle)
}