Refactor

dns/override/dns_override_darwin.go

@@ -0,0 +1,68 @@
+//go:build darwin && !ios
+
+package olm
+
+import (
+	"fmt"
+	"net/netip"
+
+	"github.com/fosrl/newt/logger"
+	"github.com/fosrl/olm/dns"
+	platform "github.com/fosrl/olm/dns/platform"
+)
+
+var configurator platform.DNSConfigurator
+
+// SetupDNSOverride configures the system DNS to use the DNS proxy on macOS
+// Uses scutil for DNS configuration
+func SetupDNSOverride(interfaceName string, dnsProxy *dns.DNSProxy) error {
+	if dnsProxy == nil {
+		return fmt.Errorf("DNS proxy is nil")
+	}
+
+	var err error
+	configurator, err = platform.NewDarwinDNSConfigurator()
+	if err != nil {
+		return fmt.Errorf("failed to create Darwin DNS configurator: %w", err)
+	}
+
+	logger.Info("Using Darwin scutil DNS configurator")
+
+	// Get current DNS servers before changing
+	currentDNS, err := configurator.GetCurrentDNS()
+	if err != nil {
+		logger.Warn("Could not get current DNS: %v", err)
+	} else {
+		logger.Info("Current DNS servers: %v", currentDNS)
+	}
+
+	// Set new DNS servers to point to our proxy
+	newDNS := []netip.Addr{
+		dnsProxy.GetProxyIP(),
+	}
+
+	logger.Info("Setting DNS servers to: %v", newDNS)
+	originalDNS, err := configurator.SetDNS(newDNS)
+	if err != nil {
+		return fmt.Errorf("failed to set DNS: %w", err)
+	}
+
+	logger.Info("Original DNS servers backed up: %v", originalDNS)
+	return nil
+}
+
+// RestoreDNSOverride restores the original DNS configuration
+func RestoreDNSOverride() error {
+	if configurator == nil {
+		logger.Debug("No DNS configurator to restore")
+		return nil
+	}
+
+	logger.Info("Restoring original DNS configuration")
+	if err := configurator.RestoreDNS(); err != nil {
+		return fmt.Errorf("failed to restore DNS: %w", err)
+	}
+
+	logger.Info("DNS configuration restored successfully")
+	return nil
+}

dns/override/dns_override_unix.go

@@ -0,0 +1,104 @@
+//go:build (linux && !android) || freebsd
+
+package olm
+
+import (
+	"fmt"
+	"net/netip"
+
+	"github.com/fosrl/newt/logger"
+	"github.com/fosrl/olm/dns"
+	platform "github.com/fosrl/olm/dns/platform"
+)
+
+var configurator platform.DNSConfigurator
+
+// SetupDNSOverride configures the system DNS to use the DNS proxy on Linux/FreeBSD
+// Tries systemd-resolved, NetworkManager, resolvconf, or falls back to /etc/resolv.conf
+func SetupDNSOverride(interfaceName string, dnsProxy *dns.DNSProxy) error {
+	if dnsProxy == nil {
+		return fmt.Errorf("DNS proxy is nil")
+	}
+
+	var err error
+
+	// Try systemd-resolved first (most modern)
+	if platform.IsSystemdResolvedAvailable() && interfaceName != "" {
+		configurator, err = platform.NewSystemdResolvedDNSConfigurator(interfaceName)
+		if err == nil {
+			logger.Info("Using systemd-resolved DNS configurator")
+			return setDNS(dnsProxy, configurator)
+		}
+		logger.Debug("systemd-resolved not available: %v", err)
+	}
+
+	// Try NetworkManager (common on desktops)
+	if platform.IsNetworkManagerAvailable() && interfaceName != "" {
+		configurator, err = platform.NewNetworkManagerDNSConfigurator(interfaceName)
+		if err == nil {
+			logger.Info("Using NetworkManager DNS configurator")
+			return setDNS(dnsProxy, configurator)
+		}
+		logger.Debug("NetworkManager not available: %v", err)
+	}
+
+	// Try resolvconf (common on older systems)
+	if platform.IsResolvconfAvailable() && interfaceName != "" {
+		configurator, err = platform.NewResolvconfDNSConfigurator(interfaceName)
+		if err == nil {
+			logger.Info("Using resolvconf DNS configurator")
+			return setDNS(dnsProxy, configurator)
+		}
+		logger.Debug("resolvconf not available: %v", err)
+	}
+
+	// Fall back to direct file manipulation
+	configurator, err = platform.NewFileDNSConfigurator()
+	if err != nil {
+		return fmt.Errorf("failed to create file DNS configurator: %w", err)
+	}
+
+	logger.Info("Using file-based DNS configurator")
+	return setDNS(dnsProxy, configurator)
+}
+
+// setDNS is a helper function to set DNS and log the results
+func setDNS(dnsProxy *dns.DNSProxy, conf platform.DNSConfigurator) error {
+	// Get current DNS servers before changing
+	currentDNS, err := conf.GetCurrentDNS()
+	if err != nil {
+		logger.Warn("Could not get current DNS: %v", err)
+	} else {
+		logger.Info("Current DNS servers: %v", currentDNS)
+	}
+
+	// Set new DNS servers to point to our proxy
+	newDNS := []netip.Addr{
+		dnsProxy.GetProxyIP(),
+	}
+
+	logger.Info("Setting DNS servers to: %v", newDNS)
+	originalDNS, err := conf.SetDNS(newDNS)
+	if err != nil {
+		return fmt.Errorf("failed to set DNS: %w", err)
+	}
+
+	logger.Info("Original DNS servers backed up: %v", originalDNS)
+	return nil
+}
+
+// RestoreDNSOverride restores the original DNS configuration
+func RestoreDNSOverride() error {
+	if configurator == nil {
+		logger.Debug("No DNS configurator to restore")
+		return nil
+	}
+
+	logger.Info("Restoring original DNS configuration")
+	if err := configurator.RestoreDNS(); err != nil {
+		return fmt.Errorf("failed to restore DNS: %w", err)
+	}
+
+	logger.Info("DNS configuration restored successfully")
+	return nil
+}

dns/override/dns_override_windows.go

@@ -0,0 +1,68 @@
+//go:build windows
+
+package olm
+
+import (
+	"fmt"
+	"net/netip"
+
+	"github.com/fosrl/newt/logger"
+	"github.com/fosrl/olm/dns"
+	platform "github.com/fosrl/olm/dns/platform"
+)
+
+var configurator platform.DNSConfigurator
+
+// SetupDNSOverride configures the system DNS to use the DNS proxy on Windows
+// Uses registry-based configuration (automatically extracts interface GUID)
+func SetupDNSOverride(interfaceName string, dnsProxy *dns.DNSProxy) error {
+	if dnsProxy == nil {
+		return fmt.Errorf("DNS proxy is nil")
+	}
+
+	var err error
+	configurator, err = platform.NewWindowsDNSConfigurator(interfaceName)
+	if err != nil {
+		return fmt.Errorf("failed to create Windows DNS configurator: %w", err)
+	}
+
+	logger.Info("Using Windows registry DNS configurator for interface: %s", interfaceName)
+
+	// Get current DNS servers before changing
+	currentDNS, err := configurator.GetCurrentDNS()
+	if err != nil {
+		logger.Warn("Could not get current DNS: %v", err)
+	} else {
+		logger.Info("Current DNS servers: %v", currentDNS)
+	}
+
+	// Set new DNS servers to point to our proxy
+	newDNS := []netip.Addr{
+		dnsProxy.GetProxyIP(),
+	}
+
+	logger.Info("Setting DNS servers to: %v", newDNS)
+	originalDNS, err := configurator.SetDNS(newDNS)
+	if err != nil {
+		return fmt.Errorf("failed to set DNS: %w", err)
+	}
+
+	logger.Info("Original DNS servers backed up: %v", originalDNS)
+	return nil
+}
+
+// RestoreDNSOverride restores the original DNS configuration
+func RestoreDNSOverride() error {
+	if configurator == nil {
+		logger.Debug("No DNS configurator to restore")
+		return nil
+	}
+
+	logger.Info("Restoring original DNS configuration")
+	if err := configurator.RestoreDNS(); err != nil {
+		return fmt.Errorf("failed to restore DNS: %w", err)
+	}
+
+	logger.Info("DNS configuration restored successfully")
+	return nil
+}