1 /*
2 *
3 * Copyright 2018 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18 19 package channelz
20 21 import (
22 "syscall"
23 24 "golang.org/x/sys/unix"
25 )
26 27 // SocketOptionData defines the struct to hold socket option data, and related
28 // getter function to obtain info from fd.
29 type SocketOptionData struct {
30 Linger *unix.Linger
31 RecvTimeout *unix.Timeval
32 SendTimeout *unix.Timeval
33 TCPInfo *unix.TCPInfo
34 }
35 36 // Getsockopt defines the function to get socket options requested by channelz.
37 // It is to be passed to syscall.RawConn.Control().
38 func (s *SocketOptionData) Getsockopt(fd uintptr) {
39 if v, err := unix.GetsockoptLinger(int(fd), syscall.SOL_SOCKET, syscall.SO_LINGER); err == nil {
40 s.Linger = v
41 }
42 if v, err := unix.GetsockoptTimeval(int(fd), syscall.SOL_SOCKET, syscall.SO_RCVTIMEO); err == nil {
43 s.RecvTimeout = v
44 }
45 if v, err := unix.GetsockoptTimeval(int(fd), syscall.SOL_SOCKET, syscall.SO_SNDTIMEO); err == nil {
46 s.SendTimeout = v
47 }
48 if v, err := unix.GetsockoptTCPInfo(int(fd), syscall.SOL_TCP, syscall.TCP_INFO); err == nil {
49 s.TCPInfo = v
50 }
51 }
52 53 // GetSocketOption gets the socket option info of the conn.
54 func GetSocketOption(socket any) *SocketOptionData {
55 c, ok := socket.(syscall.Conn)
56 if !ok {
57 return nil
58 }
59 data := &SocketOptionData{}
60 if rawConn, err := c.SyscallConn(); err == nil {
61 rawConn.Control(data.Getsockopt)
62 return data
63 }
64 return nil
65 }
66