refactor: unify loopback handling

it does not really make sense to handle the loopback interface any
different than eth, this was a leftover from before introducing a known
local port.

activator/activator.go

@@ -216,8 +216,7 @@ func (s *Server) handleConection(ctx context.Context, conn net.Conn, port uint16
 	}
 
 	if err := s.removeConnection(uint16(tcpAddr.Port)); err != nil {
-		log.G(ctx).Errorf("error removing connection: %s", err)
-		return
+		log.G(ctx).Warnf("error removing connection: %s", err)
 	}
 
 	log.G(ctx).Println("connection closed", conn.RemoteAddr().String())

activator/bpf.go

@@ -84,11 +84,6 @@ func initBPF(ifaces ...string) (*bpfObjects, func(), error) {
 		}
 		filters = append(filters, &ingress)
 
-		// for loopback we don't need an egress filter
-		if devID.Index == 1 {
-			continue
-		}
-
 		if err := netlink.FilterReplace(&egress); err != nil {
 			return nil, nil, fmt.Errorf("failed to replace tc filter: %w", err)
 		}

activator/redirector.c

@@ -113,16 +113,11 @@ static __always_inline int parse_and_redirect(struct __sk_buff *ctx, bool ingres
             if (ip->protocol == IPPROTO_TCP) {
                 struct tcphdr *tcp = (void*)ip + sizeof(*ip);
                 if ((void*)tcp + sizeof(*tcp) <= data_end) {
-                    if (ctx->ifindex == 1) {
-                        ingress_redirect(tcp);
-                        return egress_redirect(tcp);
-                    }
-
                     if (ingress) {
                         return ingress_redirect(tcp);
-                    } else {
-                        return egress_redirect(tcp);
                     }
+
+                    return egress_redirect(tcp);
                 }
             }
         }