| // Copyright 2019 Google LLC |
| // |
| // 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. |
| |
| // +build go1.11,linux |
| |
| package grpc |
| |
| import ( |
| "context" |
| "net" |
| "syscall" |
| |
| "golang.org/x/sys/unix" |
| "google.golang.org/grpc" |
| ) |
| |
| const ( |
| // defaultTCPUserTimeout is the default TCP_USER_TIMEOUT socket option. By |
| // default is 20 seconds. |
| tcpUserTimeoutMilliseconds = 20000 |
| ) |
| |
| func init() { |
| // timeoutDialerOption is a grpc.DialOption that contains dialer with |
| // socket option TCP_USER_TIMEOUT. This dialer requires go versions 1.11+. |
| timeoutDialerOption = grpc.WithContextDialer(dialTCPUserTimeout) |
| } |
| |
| func dialTCPUserTimeout(ctx context.Context, addr string) (net.Conn, error) { |
| control := func(network, address string, c syscall.RawConn) error { |
| var syscallErr error |
| controlErr := c.Control(func(fd uintptr) { |
| syscallErr = syscall.SetsockoptInt( |
| int(fd), syscall.IPPROTO_TCP, unix.TCP_USER_TIMEOUT, tcpUserTimeoutMilliseconds) |
| }) |
| if syscallErr != nil { |
| return syscallErr |
| } |
| if controlErr != nil { |
| return controlErr |
| } |
| return nil |
| } |
| d := &net.Dialer{ |
| Control: control, |
| } |
| return d.DialContext(ctx, "tcp", addr) |
| } |