Maint: port forwarding refactoring (#543)

- portforward package
- portforward run loop
- Less functional arguments and cycles

internal/portforward/state/portforwarded.go

@@ -0,0 +1,26 @@
+package state
+
+type PortForwardedGetterSetter interface {
+	PortForwardedGetter
+	SetPortForwarded(port uint16)
+}
+
+type PortForwardedGetter interface {
+	GetPortForwarded() (port uint16)
+}
+
+// GetPortForwarded is used by the control HTTP server
+// to obtain the port currently forwarded.
+func (s *State) GetPortForwarded() (port uint16) {
+	s.portForwardedMu.RLock()
+	defer s.portForwardedMu.RUnlock()
+	return s.portForwarded
+}
+
+// SetPortForwarded is only used from within the OpenVPN loop
+// to set the port forwarded.
+func (s *State) SetPortForwarded(port uint16) {
+	s.portForwardedMu.Lock()
+	defer s.portForwardedMu.Unlock()
+	s.portForwarded = port
+}

internal/portforward/state/settings.go

@@ -0,0 +1,55 @@
+package state
+
+import (
+	"context"
+	"os"
+	"reflect"
+
+	"github.com/qdm12/gluetun/internal/configuration"
+	"github.com/qdm12/gluetun/internal/constants"
+)
+
+type SettingsGetSetter interface {
+	GetSettings() (settings configuration.PortForwarding)
+	SetSettings(ctx context.Context,
+		settings configuration.PortForwarding) (outcome string)
+}
+
+func (s *State) GetSettings() (settings configuration.PortForwarding) {
+	s.settingsMu.RLock()
+	defer s.settingsMu.RUnlock()
+	return s.settings
+}
+
+func (s *State) SetSettings(ctx context.Context, settings configuration.PortForwarding) (
+	outcome string) {
+	s.settingsMu.Lock()
+
+	settingsUnchanged := reflect.DeepEqual(s.settings, settings)
+	if settingsUnchanged {
+		s.settingsMu.Unlock()
+		return "settings left unchanged"
+	}
+
+	if s.settings.Filepath != settings.Filepath {
+		_ = os.Rename(s.settings.Filepath, settings.Filepath)
+	}
+
+	newEnabled := settings.Enabled
+	previousEnabled := s.settings.Enabled
+
+	s.settings = settings
+	s.settingsMu.Unlock()
+
+	switch {
+	case !newEnabled && !previousEnabled:
+	case newEnabled && previousEnabled:
+		// no need to restart for now since we os.Rename the file here.
+	case newEnabled && !previousEnabled:
+		_, _ = s.statusApplier.ApplyStatus(ctx, constants.Running)
+	case !newEnabled && previousEnabled:
+		_, _ = s.statusApplier.ApplyStatus(ctx, constants.Stopped)
+	}
+
+	return "settings updated"
+}

internal/portforward/state/startdata.go

@@ -0,0 +1,39 @@
+package state
+
+import (
+	"net"
+
+	"github.com/qdm12/gluetun/internal/provider"
+)
+
+type StartData struct {
+	PortForwarder provider.PortForwarder
+	Gateway       net.IP // needed for PIA
+	ServerName    string // needed for PIA
+	Interface     string // tun0 or wg0 for example
+}
+
+type StartDataGetterSetter interface {
+	StartDataGetter
+	StartDataSetter
+}
+
+type StartDataGetter interface {
+	GetStartData() (startData StartData)
+}
+
+func (s *State) GetStartData() (startData StartData) {
+	s.startDataMu.RLock()
+	defer s.startDataMu.RUnlock()
+	return s.startData
+}
+
+type StartDataSetter interface {
+	SetStartData(startData StartData)
+}
+
+func (s *State) SetStartData(startData StartData) {
+	s.startDataMu.Lock()
+	defer s.startDataMu.Unlock()
+	s.startData = startData
+}

internal/portforward/state/state.go

@@ -0,0 +1,37 @@
+package state
+
+import (
+	"sync"
+
+	"github.com/qdm12/gluetun/internal/configuration"
+	"github.com/qdm12/gluetun/internal/loopstate"
+)
+
+var _ Manager = (*State)(nil)
+
+type Manager interface {
+	SettingsGetSetter
+	PortForwardedGetterSetter
+	StartDataGetterSetter
+}
+
+func New(statusApplier loopstate.Applier,
+	settings configuration.PortForwarding) *State {
+	return &State{
+		statusApplier: statusApplier,
+		settings:      settings,
+	}
+}
+
+type State struct {
+	statusApplier loopstate.Applier
+
+	settings   configuration.PortForwarding
+	settingsMu sync.RWMutex
+
+	portForwarded   uint16
+	portForwardedMu sync.RWMutex
+
+	startData   StartData
+	startDataMu sync.RWMutex
+}