Update dependencies

vendor/tailscale.com/net/tcpinfo/tcpinfo.go

@@ -0,0 +1,51 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Package tcpinfo provides platform-agnostic accessors to information about a
+// TCP connection (e.g. RTT, MSS, etc.).
+package tcpinfo
+
+import (
+	"errors"
+	"net"
+	"time"
+)
+
+var (
+	ErrNotTCP        = errors.New("tcpinfo: not a TCP conn")
+	ErrUnimplemented = errors.New("tcpinfo: unimplemented")
+)
+
+// RTT returns the RTT for the given net.Conn.
+//
+// If the net.Conn is not a *net.TCPConn and cannot be unwrapped into one, then
+// ErrNotTCP will be returned. If retrieving the RTT is not supported on the
+// current platform, ErrUnimplemented will be returned.
+func RTT(conn net.Conn) (time.Duration, error) {
+	tcpConn, err := unwrap(conn)
+	if err != nil {
+		return 0, err
+	}
+
+	return rttImpl(tcpConn)
+}
+
+// netConner is implemented by crypto/tls.Conn to unwrap into an underlying
+// net.Conn.
+type netConner interface {
+	NetConn() net.Conn
+}
+
+// unwrap attempts to unwrap a net.Conn into an underlying *net.TCPConn
+func unwrap(nc net.Conn) (*net.TCPConn, error) {
+	for {
+		switch v := nc.(type) {
+		case *net.TCPConn:
+			return v, nil
+		case netConner:
+			nc = v.NetConn()
+		default:
+			return nil, ErrNotTCP
+		}
+	}
+}

vendor/tailscale.com/net/tcpinfo/tcpinfo_darwin.go

@@ -0,0 +1,33 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package tcpinfo
+
+import (
+	"net"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+func rttImpl(conn *net.TCPConn) (time.Duration, error) {
+	rawConn, err := conn.SyscallConn()
+	if err != nil {
+		return 0, err
+	}
+
+	var (
+		tcpInfo *unix.TCPConnectionInfo
+		sysErr  error
+	)
+	err = rawConn.Control(func(fd uintptr) {
+		tcpInfo, sysErr = unix.GetsockoptTCPConnectionInfo(int(fd), unix.IPPROTO_TCP, unix.TCP_CONNECTION_INFO)
+	})
+	if err != nil {
+		return 0, err
+	} else if sysErr != nil {
+		return 0, sysErr
+	}
+
+	return time.Duration(tcpInfo.Rttcur) * time.Millisecond, nil
+}

vendor/tailscale.com/net/tcpinfo/tcpinfo_linux.go

@@ -0,0 +1,33 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package tcpinfo
+
+import (
+	"net"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+func rttImpl(conn *net.TCPConn) (time.Duration, error) {
+	rawConn, err := conn.SyscallConn()
+	if err != nil {
+		return 0, err
+	}
+
+	var (
+		tcpInfo *unix.TCPInfo
+		sysErr  error
+	)
+	err = rawConn.Control(func(fd uintptr) {
+		tcpInfo, sysErr = unix.GetsockoptTCPInfo(int(fd), unix.IPPROTO_TCP, unix.TCP_INFO)
+	})
+	if err != nil {
+		return 0, err
+	} else if sysErr != nil {
+		return 0, sysErr
+	}
+
+	return time.Duration(tcpInfo.Rtt) * time.Microsecond, nil
+}

vendor/tailscale.com/net/tcpinfo/tcpinfo_other.go

@@ -0,0 +1,15 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !linux && !darwin
+
+package tcpinfo
+
+import (
+	"net"
+	"time"
+)
+
+func rttImpl(conn *net.TCPConn) (time.Duration, error) {
+	return 0, ErrUnimplemented
+}