[client] Use platform-native routing APIs for freeBSD, macOS and Windows

client/server/trace.go

@@ -3,11 +3,11 @@ package server
 import (
 	"context"
 	"fmt"
-	"net"
 	"net/netip"
 
 	fw "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter"
+	"github.com/netbirdio/netbird/client/internal"
 	"github.com/netbirdio/netbird/client/proto"
 )
 
@@ -19,81 +19,32 @@ func (s *Server) TracePacket(_ context.Context, req *proto.TracePacketRequest) (
 	s.mutex.Lock()
 	defer s.mutex.Unlock()
 
-	if s.connectClient == nil {
-		return nil, fmt.Errorf("connect client not initialized")
-	}
-	engine := s.connectClient.Engine()
-	if engine == nil {
-		return nil, fmt.Errorf("engine not initialized")
+	tracer, engine, err := s.getPacketTracer()
+	if err != nil {
+		return nil, err
 	}
 
-	fwManager := engine.GetFirewallManager()
-	if fwManager == nil {
-		return nil, fmt.Errorf("firewall manager not initialized")
+	srcAddr, err := s.parseAddress(req.GetSourceIp(), engine)
+	if err != nil {
+		return nil, fmt.Errorf("invalid source IP address: %w", err)
 	}
 
-	tracer, ok := fwManager.(packetTracer)
-	if !ok {
-		return nil, fmt.Errorf("firewall manager does not support packet tracing")
+	dstAddr, err := s.parseAddress(req.GetDestinationIp(), engine)
+	if err != nil {
+		return nil, fmt.Errorf("invalid destination IP address: %w", err)
 	}
 
-	srcIP := net.ParseIP(req.GetSourceIp())
-	if req.GetSourceIp() == "self" {
-		srcIP = engine.GetWgAddr()
+	protocol, err := s.parseProtocol(req.GetProtocol())
+	if err != nil {
+		return nil, err
 	}
 
-	srcAddr, ok := netip.AddrFromSlice(srcIP)
-	if !ok {
-		return nil, fmt.Errorf("invalid source IP address")
+	direction, err := s.parseDirection(req.GetDirection())
+	if err != nil {
+		return nil, err
 	}
 
-	dstIP := net.ParseIP(req.GetDestinationIp())
-	if req.GetDestinationIp() == "self" {
-		dstIP = engine.GetWgAddr()
-	}
-
-	dstAddr, ok := netip.AddrFromSlice(dstIP)
-	if !ok {
-		return nil, fmt.Errorf("invalid source IP address")
-	}
-
-	if srcIP == nil || dstIP == nil {
-		return nil, fmt.Errorf("invalid IP address")
-	}
-
-	var tcpState *uspfilter.TCPState
-	if flags := req.GetTcpFlags(); flags != nil {
-		tcpState = &uspfilter.TCPState{
-			SYN: flags.GetSyn(),
-			ACK: flags.GetAck(),
-			FIN: flags.GetFin(),
-			RST: flags.GetRst(),
-			PSH: flags.GetPsh(),
-			URG: flags.GetUrg(),
-		}
-	}
-
-	var dir fw.RuleDirection
-	switch req.GetDirection() {
-	case "in":
-		dir = fw.RuleDirectionIN
-	case "out":
-		dir = fw.RuleDirectionOUT
-	default:
-		return nil, fmt.Errorf("invalid direction")
-	}
-
-	var protocol fw.Protocol
-	switch req.GetProtocol() {
-	case "tcp":
-		protocol = fw.ProtocolTCP
-	case "udp":
-		protocol = fw.ProtocolUDP
-	case "icmp":
-		protocol = fw.ProtocolICMP
-	default:
-		return nil, fmt.Errorf("invalid protocolcol")
-	}
+	tcpState := s.parseTCPFlags(req.GetTcpFlags())
 
 	builder := &uspfilter.PacketBuilder{
 		SrcIP:     srcAddr,
@@ -101,16 +52,96 @@ func (s *Server) TracePacket(_ context.Context, req *proto.TracePacketRequest) (
 		Protocol:  protocol,
 		SrcPort:   uint16(req.GetSourcePort()),
 		DstPort:   uint16(req.GetDestinationPort()),
-		Direction: dir,
+		Direction: direction,
 		TCPState:  tcpState,
 		ICMPType:  uint8(req.GetIcmpType()),
 		ICMPCode:  uint8(req.GetIcmpCode()),
 	}
+
 	trace, err := tracer.TracePacketFromBuilder(builder)
 	if err != nil {
 		return nil, fmt.Errorf("trace packet: %w", err)
 	}
 
+	return s.buildTraceResponse(trace), nil
+}
+
+func (s *Server) getPacketTracer() (packetTracer, *internal.Engine, error) {
+	if s.connectClient == nil {
+		return nil, nil, fmt.Errorf("connect client not initialized")
+	}
+
+	engine := s.connectClient.Engine()
+	if engine == nil {
+		return nil, nil, fmt.Errorf("engine not initialized")
+	}
+
+	fwManager := engine.GetFirewallManager()
+	if fwManager == nil {
+		return nil, nil, fmt.Errorf("firewall manager not initialized")
+	}
+
+	tracer, ok := fwManager.(packetTracer)
+	if !ok {
+		return nil, nil, fmt.Errorf("firewall manager does not support packet tracing")
+	}
+
+	return tracer, engine, nil
+}
+
+func (s *Server) parseAddress(addr string, engine *internal.Engine) (netip.Addr, error) {
+	if addr == "self" {
+		return engine.GetWgAddr(), nil
+	}
+
+	a, err := netip.ParseAddr(addr)
+	if err != nil {
+		return netip.Addr{}, err
+	}
+
+	return a.Unmap(), nil
+}
+
+func (s *Server) parseProtocol(protocol string) (fw.Protocol, error) {
+	switch protocol {
+	case "tcp":
+		return fw.ProtocolTCP, nil
+	case "udp":
+		return fw.ProtocolUDP, nil
+	case "icmp":
+		return fw.ProtocolICMP, nil
+	default:
+		return "", fmt.Errorf("invalid protocol")
+	}
+}
+
+func (s *Server) parseDirection(direction string) (fw.RuleDirection, error) {
+	switch direction {
+	case "in":
+		return fw.RuleDirectionIN, nil
+	case "out":
+		return fw.RuleDirectionOUT, nil
+	default:
+		return 0, fmt.Errorf("invalid direction")
+	}
+}
+
+func (s *Server) parseTCPFlags(flags *proto.TCPFlags) *uspfilter.TCPState {
+	if flags == nil {
+		return nil
+	}
+
+	return &uspfilter.TCPState{
+		SYN: flags.GetSyn(),
+		ACK: flags.GetAck(),
+		FIN: flags.GetFin(),
+		RST: flags.GetRst(),
+		PSH: flags.GetPsh(),
+		URG: flags.GetUrg(),
+	}
+}
+
+func (s *Server) buildTraceResponse(trace *uspfilter.PacketTrace) *proto.TracePacketResponse {
 	resp := &proto.TracePacketResponse{}
 
 	for _, result := range trace.Results {
@@ -119,10 +150,12 @@ func (s *Server) TracePacket(_ context.Context, req *proto.TracePacketRequest) (
 			Message: result.Message,
 			Allowed: result.Allowed,
 		}
+
 		if result.ForwarderAction != nil {
 			details := fmt.Sprintf("%s to %s", result.ForwarderAction.Action, result.ForwarderAction.RemoteAddr)
 			stage.ForwardingDetails = &details
 		}
+
 		resp.Stages = append(resp.Stages, stage)
 	}
 
@@ -130,5 +163,5 @@ func (s *Server) TracePacket(_ context.Context, req *proto.TracePacketRequest) (
 		resp.FinalDisposition = trace.Results[len(trace.Results)-1].Allowed
 	}
 
-	return resp, nil
+	return resp
 }