Drop signaling-side ICE candidate filter, drop overlay STUN at mux read-side instead

client/internal/engine.go

@@ -54,7 +54,6 @@ import (
 	"github.com/netbirdio/netbird/client/internal/relay"
 	"github.com/netbirdio/netbird/client/internal/rosenpass"
 	"github.com/netbirdio/netbird/client/internal/routemanager"
-	"github.com/netbirdio/netbird/client/internal/routemanager/systemops"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 	"github.com/netbirdio/netbird/client/internal/updater"
 	"github.com/netbirdio/netbird/client/jobexec"
@@ -1876,7 +1875,6 @@ func (e *Engine) newWgIface() (*iface.WGIface, error) {
 		WGPrivKey:    e.config.WgPrivateKey.String(),
 		MTU:          e.config.MTU,
 		TransportNet: transportNet,
-		FilterFn:     e.addrViaRoutes,
 		DisableDNS:   e.config.DisableDNS,
 	}
 
@@ -2101,21 +2099,6 @@ func (e *Engine) startNetworkMonitor() {
 	}()
 }
 
-func (e *Engine) addrViaRoutes(addr netip.Addr) (bool, netip.Prefix, error) {
-	var vpnRoutes []netip.Prefix
-	for _, routes := range e.routeManager.GetClientRoutes() {
-		if len(routes) > 0 && routes[0] != nil {
-			vpnRoutes = append(vpnRoutes, routes[0].Network)
-		}
-	}
-
-	if isVpn, prefix := systemops.IsAddrRouted(addr, vpnRoutes); isVpn {
-		return true, prefix, nil
-	}
-
-	return false, netip.Prefix{}, nil
-}
-
 func (e *Engine) stopDNSServer() {
 	if e.dnsServer == nil {
 		return

client/internal/peer/worker_ice.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"net"
-	"net/netip"
 	"strconv"
 	"sync"
 	"time"
@@ -165,10 +164,6 @@ func (w *WorkerICE) OnRemoteCandidate(candidate ice.Candidate, haRoutes route.HA
 		return
 	}
 
-	if candidateViaRoutes(candidate, haRoutes) {
-		return
-	}
-
 	if err := w.agent.AddRemoteCandidate(candidate); err != nil {
 		w.log.Errorf("error while handling remote candidate")
 		return
@@ -589,34 +584,6 @@ func extraSrflxCandidate(candidate ice.Candidate) (*ice.CandidateServerReflexive
 	return ec, nil
 }
 
-func candidateViaRoutes(candidate ice.Candidate, clientRoutes route.HAMap) bool {
-	addr, err := netip.ParseAddr(candidate.Address())
-	if err != nil {
-		log.Errorf("Failed to parse IP address %s: %v", candidate.Address(), err)
-		return false
-	}
-
-	var routePrefixes []netip.Prefix
-	for _, routes := range clientRoutes {
-		if len(routes) > 0 && routes[0] != nil {
-			routePrefixes = append(routePrefixes, routes[0].Network)
-		}
-	}
-
-	for _, prefix := range routePrefixes {
-		// default route is handled by route exclusion / ip rules
-		if prefix.Bits() == 0 {
-			continue
-		}
-
-		if prefix.Contains(addr) {
-			log.Debugf("Ignoring candidate [%s], its address is part of routed network %s", candidate.String(), prefix)
-			return true
-		}
-	}
-	return false
-}
-
 func isRelayCandidate(candidate ice.Candidate) bool {
 	return candidate.Type() == ice.CandidateTypeRelay
 }

client/internal/routemanager/systemops/systemops_generic.go

@@ -121,9 +121,12 @@ func (r *SysOps) addRouteToNonVPNIntf(prefix netip.Prefix, vpnIntf wgIface, init
 		return Nexthop{}, vars.ErrRouteNotAllowed
 	}
 
-	// Check if the prefix is part of any local subnets
-	if isLocal, subnet := r.isPrefixInLocalSubnets(prefix); isLocal {
-		return Nexthop{}, fmt.Errorf("prefix %s is part of local subnet %s: %w", prefix, subnet, vars.ErrRouteNotAllowed)
+	// BSDs blackhole a /32 added inside a directly-connected subnet; Linux/Windows need it to beat the wt0 route.
+	switch runtime.GOOS {
+	case "darwin", "freebsd", "netbsd", "openbsd", "dragonfly":
+		if isLocal, subnet := r.isPrefixInLocalSubnets(prefix); isLocal {
+			return Nexthop{}, fmt.Errorf("prefix %s is part of local subnet %s: %w", prefix, subnet, vars.ErrRouteNotAllowed)
+		}
 	}
 
 	// Determine the exit interface and next hop for the prefix, so we can add a specific route