Reorg the files

Former-commit-id: 5505c1d2c7

device/middle_device.go

@@ -1,7 +1,6 @@
-package olm
+package device
 
 import (
-	"encoding/binary"
 	"net/netip"
 	"sync"
 
@@ -17,23 +16,23 @@ type FilterRule struct {
 	Handler PacketHandler
 }
 
-// FilteredDevice wraps a TUN device with packet filtering capabilities
+// MiddleDevice wraps a TUN device with packet filtering capabilities
-type FilteredDevice struct {
+type MiddleDevice struct {
 	tun.Device
 	rules []FilterRule
 	mutex sync.RWMutex
 }
 
-// NewFilteredDevice creates a new filtered TUN device wrapper
+// NewMiddleDevice creates a new filtered TUN device wrapper
-func NewFilteredDevice(device tun.Device) *FilteredDevice {
+func NewMiddleDevice(device tun.Device) *MiddleDevice {
-	return &FilteredDevice{
+	return &MiddleDevice{
 		Device: device,
 		rules:  make([]FilterRule, 0),
 	}
 }
 
 // AddRule adds a packet filtering rule
-func (d *FilteredDevice) AddRule(destIP netip.Addr, handler PacketHandler) {
+func (d *MiddleDevice) AddRule(destIP netip.Addr, handler PacketHandler) {
 	d.mutex.Lock()
 	defer d.mutex.Unlock()
 	d.rules = append(d.rules, FilterRule{
@@ -43,7 +42,7 @@ func (d *FilteredDevice) AddRule(destIP netip.Addr, handler PacketHandler) {
 }
 
 // RemoveRule removes all rules for a given destination IP
-func (d *FilteredDevice) RemoveRule(destIP netip.Addr) {
+func (d *MiddleDevice) RemoveRule(destIP netip.Addr) {
 	d.mutex.Lock()
 	defer d.mutex.Unlock()
 	newRules := make([]FilterRule, 0, len(d.rules))
@@ -86,7 +85,7 @@ func extractDestIP(packet []byte) (netip.Addr, bool) {
 }
 
 // Read intercepts packets going UP from the TUN device (towards WireGuard)
-func (d *FilteredDevice) Read(bufs [][]byte, sizes []int, offset int) (n int, err error) {
+func (d *MiddleDevice) Read(bufs [][]byte, sizes []int, offset int) (n int, err error) {
 	n, err = d.Device.Read(bufs, sizes, offset)
 	if err != nil || n == 0 {
 		return n, err
@@ -142,7 +141,7 @@ func (d *FilteredDevice) Read(bufs [][]byte, sizes []int, offset int) (n int, er
 }
 
 // Write intercepts packets going DOWN to the TUN device (from WireGuard)
-func (d *FilteredDevice) Write(bufs [][]byte, offset int) (int, error) {
+func (d *MiddleDevice) Write(bufs [][]byte, offset int) (int, error) {
 	d.mutex.RLock()
 	rules := d.rules
 	d.mutex.RUnlock()
@@ -189,49 +188,3 @@ func (d *FilteredDevice) Write(bufs [][]byte, offset int) (int, error) {
 
 	return d.Device.Write(filteredBufs, offset)
 }
-
-// GetProtocol returns protocol number from IPv4 packet (fast path)
-func GetProtocol(packet []byte) (uint8, bool) {
-	if len(packet) < 20 {
-		return 0, false
-	}
-	version := packet[0] >> 4
-	if version == 4 {
-		return packet[9], true
-	} else if version == 6 {
-		if len(packet) < 40 {
-			return 0, false
-		}
-		return packet[6], true
-	}
-	return 0, false
-}
-
-// GetDestPort returns destination port from TCP/UDP packet (fast path)
-func GetDestPort(packet []byte) (uint16, bool) {
-	if len(packet) < 20 {
-		return 0, false
-	}
-
-	version := packet[0] >> 4
-	var headerLen int
-
-	if version == 4 {
-		ihl := packet[0] & 0x0F
-		headerLen = int(ihl) * 4
-		if len(packet) < headerLen+4 {
-			return 0, false
-		}
-	} else if version == 6 {
-		headerLen = 40
-		if len(packet) < headerLen+4 {
-			return 0, false
-		}
-	} else {
-		return 0, false
-	}
-
-	// Destination port is at bytes 2-3 of TCP/UDP header
-	port := binary.BigEndian.Uint16(packet[headerLen+2 : headerLen+4])
-	return port, true
-}

device/middle_device_test.go

@@ -1,8 +1,10 @@
-package olm
+package device
 
 import (
 	"net/netip"
 	"testing"
+
+	"github.com/fosrl/newt/util"
 )
 
 func TestExtractDestIP(t *testing.T) {
@@ -74,7 +76,7 @@ func TestGetProtocol(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			gotProto, gotOk := GetProtocol(tt.packet)
+			gotProto, gotOk := util.GetProtocol(tt.packet)
 			if gotOk != tt.wantOk {
 				t.Errorf("GetProtocol() ok = %v, want %v", gotOk, tt.wantOk)
 				return

dns/dns_proxy.go

@@ -1,4 +1,4 @@
-package olm
+package dns
 
 import (
 	"context"
@@ -9,6 +9,8 @@ import (
 	"time"
 
 	"github.com/fosrl/newt/logger"
+	"github.com/fosrl/newt/util"
+	"github.com/fosrl/olm/device"
 	"golang.zx2c4.com/wireguard/tun"
 	"gvisor.dev/gvisor/pkg/buffer"
 	"gvisor.dev/gvisor/pkg/tcpip"
@@ -96,9 +98,9 @@ func NewDNSProxy(tunDevice tun.Device, mtu int) (*DNSProxy, error) {
 }
 
 // Start starts the DNS proxy and registers with the filter
-func (p *DNSProxy) Start(filter *FilteredDevice) error {
+func (p *DNSProxy) Start(device *device.MiddleDevice) error {
 	// Install packet filter rule
-	filter.AddRule(p.proxyIP, p.handlePacket)
+	device.AddRule(p.proxyIP, p.handlePacket)
 
 	// Start DNS listener
 	p.wg.Add(2)
@@ -110,9 +112,9 @@ func (p *DNSProxy) Start(filter *FilteredDevice) error {
 }
 
 // Stop stops the DNS proxy
-func (p *DNSProxy) Stop(filter *FilteredDevice) {
+func (p *DNSProxy) Stop(device *device.MiddleDevice) {
-	if filter != nil {
+	if device != nil {
-		filter.RemoveRule(p.proxyIP)
+		device.RemoveRule(p.proxyIP)
 	}
 	p.cancel()
 	p.wg.Wait()
@@ -134,12 +136,12 @@ func (p *DNSProxy) handlePacket(packet []byte) bool {
 	}
 
 	// Quick check for UDP port 53
-	proto, ok := GetProtocol(packet)
+	proto, ok := util.GetProtocol(packet)
 	if !ok || proto != 17 { // 17 = UDP
 		return false // Not UDP, don't handle
 	}
 
-	port, ok := GetDestPort(packet)
+	port, ok := util.GetDestPort(packet)
 	if !ok || port != DNSPort {
 		return false // Not DNS port
 	}

olm/olm.go

@@ -13,6 +13,8 @@ import (
 	"github.com/fosrl/newt/logger"
 	"github.com/fosrl/newt/util"
 	"github.com/fosrl/olm/api"
+	middleDevice "github.com/fosrl/olm/device"
+	"github.com/fosrl/olm/dns"
 	"github.com/fosrl/olm/network"
 	"github.com/fosrl/olm/peermonitor"
 	"github.com/fosrl/olm/websocket"
@@ -70,8 +72,8 @@ var (
 	holePunchData    HolePunchData
 	uapiListener     net.Listener
 	tdev             tun.Device
-	filteredDev      *FilteredDevice
+	middleDev        *middleDevice.MiddleDevice
-	dnsProxy         *DNSProxy
+	dnsProxy         *dns.DNSProxy
 	apiServer        *api.API
 	olmClient        *websocket.Client
 	tunnelCancel     context.CancelFunc
@@ -427,15 +429,15 @@ func StartTunnel(config TunnelConfig) {
 		}
 
 		// Wrap TUN device with packet filter for DNS proxy
-		filteredDev = NewFilteredDevice(tdev)
+		middleDev = middleDevice.NewMiddleDevice(tdev)
 
 		// Create and start DNS proxy
-		dnsProxy, err = NewDNSProxy(tdev, config.MTU)
+		dnsProxy, err = dns.NewDNSProxy(tdev, config.MTU)
 		if err != nil {
 			logger.Error("Failed to create DNS proxy: %v", err)
 			return
 		}
-		if err := dnsProxy.Start(filteredDev); err != nil {
+		if err := dnsProxy.Start(middleDev); err != nil {
 			logger.Error("Failed to start DNS proxy: %v", err)
 			return
 		}
@@ -458,7 +460,7 @@ func StartTunnel(config TunnelConfig) {
 
 		wgLogger := logger.GetLogger().GetWireGuardLogger("wireguard: ")
 		// Use filtered device instead of raw TUN device
-		dev = device.NewDevice(filteredDev, sharedBind, (*device.Logger)(wgLogger))
+		dev = device.NewDevice(middleDev, sharedBind, (*device.Logger)(wgLogger))
 
 		// uapiListener, err = uapiListen(interfaceName, fileUAPI)
 		// if err != nil {
@@ -1067,13 +1069,13 @@ func Close() {
 
 	// Stop DNS proxy
 	if dnsProxy != nil {
-		dnsProxy.Stop(filteredDev)
+		dnsProxy.Stop(middleDev)
 		dnsProxy = nil
 	}
 
 	// Clear filtered device
-	if filteredDev != nil {
+	if middleDev != nil {
-		filteredDev = nil
+		middleDev = nil
 	}
 
 	// Close TUN device