Update dependencies

vendor/tailscale.com/net/netcheck/standalone.go

@@ -0,0 +1,102 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package netcheck
+
+import (
+	"context"
+	"errors"
+	"net/netip"
+
+	"tailscale.com/net/netaddr"
+	"tailscale.com/net/netns"
+	"tailscale.com/net/stun"
+	"tailscale.com/types/logger"
+	"tailscale.com/types/nettype"
+	"tailscale.com/util/multierr"
+)
+
+// Standalone creates the necessary UDP sockets on the given bindAddr and starts
+// an IO loop so that the Client can perform active probes with no further need
+// for external driving of IO (no need to set/implement SendPacket, or call
+// ReceiveSTUNPacket). It must be called prior to starting any reports and is
+// shut down by cancellation of the provided context. If both IPv4 and IPv6 fail
+// to bind, errors will be returned, if one or both protocols can bind no error
+// is returned.
+func (c *Client) Standalone(ctx context.Context, bindAddr string) error {
+	if c.NetMon == nil {
+		panic("netcheck.Client.NetMon must be set")
+	}
+	if bindAddr == "" {
+		bindAddr = ":0"
+	}
+	var errs []error
+
+	u4, err := nettype.MakePacketListenerWithNetIP(netns.Listener(c.logf, c.NetMon)).ListenPacket(ctx, "udp4", bindAddr)
+	if err != nil {
+		c.logf("udp4: %v", err)
+		errs = append(errs, err)
+	} else {
+		go readPackets(ctx, c.logf, u4, c.ReceiveSTUNPacket)
+	}
+
+	u6, err := nettype.MakePacketListenerWithNetIP(netns.Listener(c.logf, c.NetMon)).ListenPacket(ctx, "udp6", bindAddr)
+	if err != nil {
+		c.logf("udp6: %v", err)
+		errs = append(errs, err)
+	} else {
+		go readPackets(ctx, c.logf, u6, c.ReceiveSTUNPacket)
+	}
+
+	c.SendPacket = func(pkt []byte, dst netip.AddrPort) (int, error) {
+		pc := u4
+		if dst.Addr().Is6() {
+			pc = u6
+		}
+		if pc == nil {
+			return 0, errors.New("no UDP socket")
+		}
+
+		return pc.WriteToUDPAddrPort(pkt, dst)
+	}
+
+	// If both v4 and v6 failed, report an error, otherwise let one succeed.
+	if len(errs) == 2 {
+		return multierr.New(errs...)
+	}
+	return nil
+}
+
+// readPackets reads STUN packets from pc until there's an error or ctx is done.
+// In either case, it closes pc.
+func readPackets(ctx context.Context, logf logger.Logf, pc nettype.PacketConn, recv func([]byte, netip.AddrPort)) {
+	done := make(chan struct{})
+	defer close(done)
+
+	go func() {
+		select {
+		case <-ctx.Done():
+		case <-done:
+		}
+		pc.Close()
+	}()
+
+	var buf [64 << 10]byte
+	for {
+		n, addr, err := pc.ReadFromUDPAddrPort(buf[:])
+		if err != nil {
+			if ctx.Err() != nil {
+				return
+			}
+			logf("ReadFrom: %v", err)
+			return
+		}
+		pkt := buf[:n]
+		if !stun.Is(pkt) {
+			continue
+		}
+		if ap := netaddr.Unmap(addr); ap.IsValid() {
+			recv(pkt, ap)
+		}
+	}
+}