tnet

Author: null

proxy/wireguard/client.go

@@ -3,7 +3,6 @@ package wireguard
 import (
 	"context"
 	"fmt"
-	gonet "net"
 	"net/netip"
 	reflect "reflect"
 	"strings"
@@ -126,22 +125,6 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 		}
 	}
 
-	var addr netip.Addr
-	if ob.Target.Address.Family().IsDomain() {
-		ip, err := h.resolveRemote(ob.Target.Address.String())
-		if err != nil {
-			return errors.New("failed to resolve domain").Base(err)
-		}
-		addr, _ = netip.AddrFromSlice(ip)
-	} else {
-		addr, _ = netip.AddrFromSlice(ob.Target.Address.IP())
-	}
-
-	addrPort := netip.AddrPortFrom(addr, ob.Target.Port.Value())
-	if !addrPort.IsValid() {
-		return errors.New("invalid target ", ob.Target)
-	}
-
 	var newCtx context.Context
 	var newCancel context.CancelFunc
 	if session.TimeoutOnlyFromContext(ctx) {
@@ -166,23 +149,33 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 
 	switch ob.Target.Network {
 	case net.Network_TCP:
-		conn, err := h.tnet.DialContextTCPAddrPort(ctx, addrPort)
+		conn, err := h.tnet.Dial("tcp", ob.Target.NetAddr())
 		if err != nil {
 			return errors.New("failed to create TCP connection").Base(err)
 		}
 		defer conn.Close()
 		reader = buf.NewReader(conn)
 		writer = buf.NewWriter(conn)
 	case net.Network_UDP:
-		conn, err := h.tnet.DialUDPAddrPort(netip.AddrPort{}, addrPort)
+		var dest *net.UDPAddr
+		if ob.Target.Address.Family().IsDomain() {
+			ip, err := h.resolveRemote(ob.Target.Address.String())
+			if err != nil {
+				return errors.New("failed to resolve domain").Base(err)
+			}
+			dest = &net.UDPAddr{IP: ip, Port: int(ob.Target.Port)}
+		} else {
+			dest = &net.UDPAddr{IP: ob.Target.Address.IP(), Port: int(ob.Target.Port)}
+		}
+		conn, err := h.tnet.DialUDPAddrPort(netip.AddrPort{}, netip.AddrPort{})
 		if err != nil {
 			return errors.New("failed to create UDP connection").Base(err)
 		}
 		defer conn.Close()
 		c := &udpConnClient{
 			PacketConn:  conn.(*internet.PacketConnWrapper).PacketConn,
 			resolveFunc: h.resolveRemote,
-			dest:        gonet.UDPAddrFromAddrPort(addrPort),
+			dest:        dest,
 		}
 		reader = c
 		writer = c

proxy/wireguard/netstack.go

@@ -15,6 +15,8 @@ import (
 	"net"
 	"net/netip"
 	"os"
+	"regexp"
+	"strconv"
 	"strings"
 	"syscall"
 	"time"
@@ -246,6 +248,9 @@ var (
 	errServerTemporarilyMisbehaving = errors.New("server misbehaving")
 	errCanceled                     = errors.New("operation was canceled")
 	errTimeout                      = errors.New("i/o timeout")
+	errNumericPort                  = errors.New("port must be numeric")
+	errNoSuitableAddress            = errors.New("no suitable address found")
+	errMissingAddress               = errors.New("missing address")
 )
 
 func (net *Net) LookupHost(host string) (addrs []string, err error) {
@@ -688,3 +693,116 @@ func (tnet *Net) LookupContextHost(ctx context.Context, host string) ([]string,
 	}
 	return saddrs, nil
 }
+
+func partialDeadline(now, deadline time.Time, addrsRemaining int) (time.Time, error) {
+	if deadline.IsZero() {
+		return deadline, nil
+	}
+	timeRemaining := deadline.Sub(now)
+	if timeRemaining <= 0 {
+		return time.Time{}, errTimeout
+	}
+	timeout := timeRemaining / time.Duration(addrsRemaining)
+	const saneMinimum = 2 * time.Second
+	if timeout < saneMinimum {
+		if timeRemaining < saneMinimum {
+			timeout = timeRemaining
+		} else {
+			timeout = saneMinimum
+		}
+	}
+	return now.Add(timeout), nil
+}
+
+var protoSplitter = regexp.MustCompile(`^(tcp)(4|6)?$`)
+
+func (tnet *Net) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
+	if ctx == nil {
+		panic("nil context")
+	}
+	var acceptV4, acceptV6 bool
+	matches := protoSplitter.FindStringSubmatch(network)
+	if matches == nil {
+		return nil, &net.OpError{Op: "dial", Err: net.UnknownNetworkError(network)}
+	} else if len(matches[2]) == 0 {
+		acceptV4 = true
+		acceptV6 = true
+	} else {
+		acceptV4 = matches[2][0] == '4'
+		acceptV6 = !acceptV4
+	}
+	var host string
+	var port int
+	var sport string
+	var err error
+	host, sport, err = net.SplitHostPort(address)
+	if err != nil {
+		return nil, &net.OpError{Op: "dial", Err: err}
+	}
+	port, err = strconv.Atoi(sport)
+	if err != nil || port < 0 || port > 65535 {
+		return nil, &net.OpError{Op: "dial", Err: errNumericPort}
+	}
+	allAddr, err := tnet.LookupContextHost(ctx, host)
+	if err != nil {
+		return nil, &net.OpError{Op: "dial", Err: err}
+	}
+	var addrs []netip.AddrPort
+	for _, addr := range allAddr {
+		ip, err := netip.ParseAddr(addr)
+		if err == nil && ((ip.Is4() && acceptV4) || (ip.Is6() && acceptV6)) {
+			addrs = append(addrs, netip.AddrPortFrom(ip, uint16(port)))
+		}
+	}
+	if len(addrs) == 0 && len(allAddr) != 0 {
+		return nil, &net.OpError{Op: "dial", Err: errNoSuitableAddress}
+	}
+
+	var firstErr error
+	for i, addr := range addrs {
+		select {
+		case <-ctx.Done():
+			err := ctx.Err()
+			if err == context.Canceled {
+				err = errCanceled
+			} else if err == context.DeadlineExceeded {
+				err = errTimeout
+			}
+			return nil, &net.OpError{Op: "dial", Err: err}
+		default:
+		}
+
+		dialCtx := ctx
+		if deadline, hasDeadline := ctx.Deadline(); hasDeadline {
+			partialDeadline, err := partialDeadline(time.Now(), deadline, len(addrs)-i)
+			if err != nil {
+				if firstErr == nil {
+					firstErr = &net.OpError{Op: "dial", Err: err}
+				}
+				break
+			}
+			if partialDeadline.Before(deadline) {
+				var cancel context.CancelFunc
+				dialCtx, cancel = context.WithDeadline(ctx, partialDeadline)
+				defer cancel()
+			}
+		}
+
+		var c net.Conn
+		c, err = tnet.DialContextTCPAddrPort(dialCtx, addr)
+		if err == nil {
+			return c, nil
+		}
+		if firstErr == nil {
+			firstErr = err
+		}
+	}
+	if firstErr == nil {
+		firstErr = &net.OpError{Op: "dial", Err: errMissingAddress}
+	}
+	return nil, firstErr
+}
+
+func (tnet *Net) Dial(network, address string) (net.Conn, error) {
+	return tnet.DialContext(context.Background(), network, address)
+}