1 files changed, 54 insertions, 0 deletions
diff --git a/vendor/github.com/go-sql-driver/mysql/conncheck.go b/vendor/github.com/go-sql-driver/mysql/conncheck.go
new file mode 100644
index 0000000..024eb28
--- /dev/null
+++ b/vendor/github.com/go-sql-driver/mysql/conncheck.go
@@ -0,0 +1,54 @@
+// Go MySQL Driver - A MySQL-Driver for Go's database/sql package
+//
+// Copyright 2019 The Go-MySQL-Driver Authors. All rights reserved.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at http://mozilla.org/MPL/2.0/.
+
+// +build linux darwin dragonfly freebsd netbsd openbsd solaris illumos
+
+package mysql
+
+import (
+	"errors"
+	"io"
+	"net"
+	"syscall"
+)
+
+var errUnexpectedRead = errors.New("unexpected read from socket")
+
+func connCheck(conn net.Conn) error {
+	var sysErr error
+
+	sysConn, ok := conn.(syscall.Conn)
+	if !ok {
+		return nil
+	}
+	rawConn, err := sysConn.SyscallConn()
+	if err != nil {
+		return err
+	}
+
+	err = rawConn.Read(func(fd uintptr) bool {
+		var buf [1]byte
+		n, err := syscall.Read(int(fd), buf[:])
+		switch {
+		case n == 0 && err == nil:
+			sysErr = io.EOF
+		case n > 0:
+			sysErr = errUnexpectedRead
+		case err == syscall.EAGAIN || err == syscall.EWOULDBLOCK:
+			sysErr = nil
+		default:
+			sysErr = err
+		}
+		return true
+	})
+	if err != nil {
+		return err
+	}
+
+	return sysErr
+}