Update dependencies

vendor/github.com/tailscale/peercred/peercred.go

@@ -0,0 +1,47 @@
+// Copyright (c) 2021 AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package peercred maps from a net.Conn to information about the
+// other side of the connection, using various OS-specific facilities.
+package peercred
+
+import (
+	"errors"
+	"net"
+	"runtime"
+)
+
+// Creds are the peer credentials.
+type Creds struct {
+	pid int
+	uid string
+}
+
+func (c *Creds) PID() (pid int, ok bool) {
+	return c.pid, c.pid != 0
+}
+
+// UserID returns the userid (or Windows SID) that owns the other side
+// of the connection, if known. (ok is false if not known)
+// The returned string is suitable to passing to os/user.LookupId.
+func (c *Creds) UserID() (uid string, ok bool) {
+	return c.uid, c.uid != ""
+}
+
+var osGet func(net.Conn) (*Creds, error)
+
+var (
+	ErrNotImplemented      = errors.New("not implemented on " + runtime.GOOS)
+	ErrUnsupportedConnType = errors.New("unsupported connection type")
+)
+
+// Get returns the peer credentials for c.
+//
+// For unsupported system, the error is ErrNotImplemented.
+func Get(c net.Conn) (*Creds, error) {
+	if osGet == nil {
+		return nil, ErrNotImplemented
+	}
+	return osGet(c)
+}