Basic working

Former-commit-id: 4dd50526cf

config.go

@@ -78,7 +78,7 @@ func DefaultConfig() *OlmConfig {
 	config := &OlmConfig{
 		MTU:           1280,
 		DNS:           "8.8.8.8",
-		UpstreamDNS:   []string{"8.8.8.8"},
+		UpstreamDNS:   []string{"8.8.8.8:53"},
 		LogLevel:      "INFO",
 		InterfaceName: "olm",
 		EnableAPI:     false,
@@ -293,7 +293,7 @@ func loadConfigFromCLI(config *OlmConfig, args []string) (bool, bool, error) {
 	serviceFlags.IntVar(&config.MTU, "mtu", config.MTU, "MTU to use")
 	serviceFlags.StringVar(&config.DNS, "dns", config.DNS, "DNS server to use")
 	var upstreamDNSFlag string
-	serviceFlags.StringVar(&upstreamDNSFlag, "upstream-dns", "", "Upstream DNS server(s) (comma-separated, default: 8.8.8.8)")
+	serviceFlags.StringVar(&upstreamDNSFlag, "upstream-dns", "", "Upstream DNS server(s) (comma-separated, default: 8.8.8.8:53)")
 	serviceFlags.StringVar(&config.LogLevel, "log-level", config.LogLevel, "Log level (DEBUG, INFO, WARN, ERROR, FATAL)")
 	serviceFlags.StringVar(&config.InterfaceName, "interface", config.InterfaceName, "Name of the WireGuard interface")
 	serviceFlags.StringVar(&config.HTTPAddr, "http-addr", config.HTTPAddr, "HTTP server address (e.g., ':9452')")
@@ -442,7 +442,7 @@ func mergeConfigs(dest, src *OlmConfig) {
 		dest.DNS = src.DNS
 		dest.sources["dns"] = string(SourceFile)
 	}
-	if len(src.UpstreamDNS) > 0 && fmt.Sprintf("%v", src.UpstreamDNS) != "[8.8.8.8]" {
+	if len(src.UpstreamDNS) > 0 && fmt.Sprintf("%v", src.UpstreamDNS) != "[8.8.8.8:53]" {
 		dest.UpstreamDNS = src.UpstreamDNS
 		dest.sources["upstreamDNS"] = string(SourceFile)
 	}

dns/dns_proxy.go

@@ -58,12 +58,14 @@ func NewDNSProxy(tunDevice tun.Device, middleDevice *device.MiddleDevice, mtu in
 	ctx, cancel := context.WithCancel(context.Background())
 
 	proxy := &DNSProxy{
-		proxyIP:     proxyIP,
-		mtu:         mtu,
-		tunDevice:   tunDevice,
-		recordStore: NewDNSRecordStore(),
-		ctx:         ctx,
-		cancel:      cancel,
+		proxyIP:      proxyIP,
+		mtu:          mtu,
+		tunDevice:    tunDevice,
+		middleDevice: middleDevice,
+		upstreamDNS:  upstreamDns,
+		recordStore:  NewDNSRecordStore(),
+		ctx:          ctx,
+		cancel:       cancel,
 	}
 
 	// Create gvisor netstack
@@ -134,6 +136,10 @@ func (p *DNSProxy) Stop() {
 	logger.Info("DNS proxy stopped")
 }
 
+func (p *DNSProxy) GetProxyIP() netip.Addr {
+	return p.proxyIP
+}
+
 // handlePacket is called by the filter for packets destined to DNS proxy IP
 func (p *DNSProxy) handlePacket(packet []byte) bool {
 	if len(packet) < 20 {
@@ -248,7 +254,7 @@ func (p *DNSProxy) handleDNSQuery(udpConn *gonet.UDPConn, queryData []byte, clie
 
 	// If no local records, forward to upstream
 	if response == nil {
-		logger.Debug("No local record for %s, forwarding upstream", question.Name)
+		logger.Debug("No local record for %s, forwarding upstream to %v", question.Name, p.upstreamDNS)
 		response = p.forwardToUpstream(msg)
 	}
 

olm/olm.go

@@ -4,7 +4,9 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"log"
 	"net"
+	"net/netip"
 	"runtime"
 	"strings"
 	"time"
@@ -16,6 +18,7 @@ import (
 	"github.com/fosrl/olm/api"
 	middleDevice "github.com/fosrl/olm/device"
 	"github.com/fosrl/olm/dns"
+	platform "github.com/fosrl/olm/dns/platform"
 	"github.com/fosrl/olm/network"
 	"github.com/fosrl/olm/peermonitor"
 	"github.com/fosrl/olm/websocket"
@@ -91,6 +94,7 @@ var (
 	globalCtx        context.Context
 	stopRegister     func()
 	stopPing         chan struct{}
+	configurator     platform.DNSConfigurator
 )
 
 func Init(ctx context.Context, config GlobalConfig) {
@@ -167,7 +171,7 @@ func Init(ctx context.Context, config GlobalConfig) {
 			// DNSProxyIP has no default - it must be provided if DNS proxy is desired
 			// UpstreamDNS defaults to 8.8.8.8 if not provided
 			if len(req.UpstreamDNS) == 0 {
-				tunnelConfig.UpstreamDNS = []string{"8.8.8.8"}
+				tunnelConfig.UpstreamDNS = []string{"8.8.8.8:53"}
 			}
 			if req.InterfaceName == "" {
 				tunnelConfig.InterfaceName = "olm"
@@ -485,6 +489,9 @@ func StartTunnel(config TunnelConfig) {
 			logger.Error("Failed to bring up WireGuard device: %v", err)
 		}
 
+		// TODO: REMOVE HARDCODE
+		wgData.UtilitySubnet = "100.81.0.0/24"
+
 		// Create and start DNS proxy
 		dnsProxy, err = dns.NewDNSProxy(tdev, middleDev, config.MTU, wgData.UtilitySubnet, config.UpstreamDNS)
 		if err != nil {
@@ -570,6 +577,37 @@ func StartTunnel(config TunnelConfig) {
 
 		peerMonitor.Start()
 
+		configurator, err = platform.DetectBestConfigurator(interfaceName)
+		if err != nil {
+			log.Fatalf("Failed to detect DNS configurator: %v", err)
+		}
+
+		fmt.Printf("Using DNS configurator: %s\n", configurator.Name())
+
+		// Get current DNS servers before changing
+		currentDNS, err := configurator.GetCurrentDNS()
+		if err != nil {
+			log.Printf("Warning: Could not get current DNS: %v", err)
+		} else {
+			fmt.Printf("Current DNS servers: %v\n", currentDNS)
+		}
+
+		// Set new DNS servers
+		newDNS := []netip.Addr{
+			dnsProxy.GetProxyIP(),
+			// netip.MustParseAddr("8.8.8.8"), // Google
+		}
+
+		fmt.Printf("Setting DNS servers to: %v\n", newDNS)
+		originalDNS, err := configurator.SetDNS(newDNS)
+		if err != nil {
+			log.Fatalf("Failed to set DNS: %v", err)
+		}
+
+		for _, addr := range originalDNS {
+			fmt.Printf("Original DNS server: %v\n", addr)
+		}
+
 		if err := dnsProxy.Start(); err != nil {
 			logger.Error("Failed to start DNS proxy: %v", err)
 		}
@@ -1110,6 +1148,14 @@ func Close() {
 		middleDev = nil
 	}
 
+	// Restore original DNS
+	if configurator != nil {
+		fmt.Println("Restoring original DNS servers...")
+		if err := configurator.RestoreDNS(); err != nil {
+			log.Fatalf("Failed to restore DNS: %v", err)
+		}
+	}
+
 	// Stop DNS proxy
 	logger.Debug("Stopping DNS proxy")
 	if dnsProxy != nil {

olm/windows.go

@@ -11,7 +11,7 @@ import (
 	"golang.zx2c4.com/wireguard/tun"
 )
 
-func createTUNFromFD(tunFdStr string, mtuInt int) (tun.Device, error) {
+func createTUNFromFD(tunFd uint32, mtuInt int) (tun.Device, error) {
 	return nil, errors.New("CreateTUNFromFile not supported on Windows")
 }