Add libbox wrapper

experimental/libbox/tun.go

@@ -0,0 +1,109 @@
+package libbox
+
+import (
+	"io"
+	"net/netip"
+	"os"
+
+	"github.com/sagernet/sing-tun"
+	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+type TunOptions interface {
+	GetInet4Address() RoutePrefixIterator
+	GetInet6Address() RoutePrefixIterator
+	GetDNSServerAddress() (string, error)
+	GetMTU() int32
+	GetAutoRoute() bool
+	GetStrictRoute() bool
+	GetInet4RouteAddress() RoutePrefixIterator
+	GetInet6RouteAddress() RoutePrefixIterator
+	GetIncludePackage() StringIterator
+	GetExcludePackage() StringIterator
+}
+
+type RoutePrefix struct {
+	Address string
+	Prefix  int32
+}
+
+type RoutePrefixIterator interface {
+	Next() *RoutePrefix
+	HasNext() bool
+}
+
+func mapRoutePrefix(prefixes []netip.Prefix) RoutePrefixIterator {
+	return newIterator(common.Map(prefixes, func(prefix netip.Prefix) *RoutePrefix {
+		return &RoutePrefix{
+			Address: prefix.Addr().String(),
+			Prefix:  int32(prefix.Bits()),
+		}
+	}))
+}
+
+var _ TunOptions = (*tunOptions)(nil)
+
+type tunOptions tun.Options
+
+func (o *tunOptions) GetInet4Address() RoutePrefixIterator {
+	return mapRoutePrefix(o.Inet4Address)
+}
+
+func (o *tunOptions) GetInet6Address() RoutePrefixIterator {
+	return mapRoutePrefix(o.Inet6Address)
+}
+
+func (o *tunOptions) GetDNSServerAddress() (string, error) {
+	if len(o.Inet4Address) == 0 || o.Inet4Address[0].Bits() == 32 {
+		return "", E.New("need one more IPv4 address for DNS hijacking")
+	}
+	return o.Inet4Address[0].Addr().Next().String(), nil
+}
+
+func (o *tunOptions) GetMTU() int32 {
+	return int32(o.MTU)
+}
+
+func (o *tunOptions) GetAutoRoute() bool {
+	return o.AutoRoute
+}
+
+func (o *tunOptions) GetStrictRoute() bool {
+	return o.StrictRoute
+}
+
+func (o *tunOptions) GetInet4RouteAddress() RoutePrefixIterator {
+	return mapRoutePrefix(o.Inet4RouteAddress)
+}
+
+func (o *tunOptions) GetInet6RouteAddress() RoutePrefixIterator {
+	return mapRoutePrefix(o.Inet6RouteAddress)
+}
+
+func (o *tunOptions) GetIncludePackage() StringIterator {
+	return newIterator(o.IncludePackage)
+}
+
+func (o *tunOptions) GetExcludePackage() StringIterator {
+	return newIterator(o.ExcludePackage)
+}
+
+type nativeTun struct {
+	tunFd   int
+	tunFile *os.File
+	tunMTU  uint32
+	closer  io.Closer
+}
+
+func (t *nativeTun) Read(p []byte) (n int, err error) {
+	return t.tunFile.Read(p)
+}
+
+func (t *nativeTun) Write(p []byte) (n int, err error) {
+	return t.tunFile.Write(p)
+}
+
+func (t *nativeTun) Close() error {
+	return t.closer.Close()
+}