blob: f499a614c20edb54405a6b563e7ee12fadd3a2ef [file] [log] [blame]
// +build !appengine
/*
*
* Copyright 2018 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package credentials
import (
"net"
"syscall"
)
type sysConn = syscall.Conn
// syscallConn keeps reference of rawConn to support syscall.Conn for channelz.
// SyscallConn() (the method in interface syscall.Conn) is explicitly
// implemented on this type,
//
// Interface syscall.Conn is implemented by most net.Conn implementations (e.g.
// TCPConn, UnixConn), but is not part of net.Conn interface. So wrapper conns
// that embed net.Conn don't implement syscall.Conn. (Side note: tls.Conn
// doesn't embed net.Conn, so even if syscall.Conn is part of net.Conn, it won't
// help here).
type syscallConn struct {
net.Conn
// sysConn is a type alias of syscall.Conn. It's necessary because the name
// `Conn` collides with `net.Conn`.
sysConn
}
// WrapSyscallConn tries to wrap rawConn and newConn into a net.Conn that
// implements syscall.Conn. rawConn will be used to support syscall, and newConn
// will be used for read/write.
//
// This function returns newConn if rawConn doesn't implement syscall.Conn.
func WrapSyscallConn(rawConn, newConn net.Conn) net.Conn {
sysConn, ok := rawConn.(syscall.Conn)
if !ok {
return newConn
}
return &syscallConn{
Conn: newConn,
sysConn: sysConn,
}
}