feat: rm hard dep on x/sys (#1742)

We only referenced a constant, so I inlined it.

Author: codyoss

go.mod

@@ -12,7 +12,6 @@ require (
 	golang.org/x/net v0.0.0-20221014081412-f15817d10f9b
 	golang.org/x/oauth2 v0.0.0-20221014153046-6fdb5e3db783
 	golang.org/x/sync v0.1.0
-	golang.org/x/sys v0.0.0-20220728004956-3c1f35247d10
 	golang.org/x/xerrors v0.0.0-20220907171357-04be3eba64a2
 	google.golang.org/appengine v1.6.7
 	google.golang.org/genproto v0.0.0-20221024183307-1bc688fe9f3e
@@ -23,6 +22,7 @@ require (
 	cloud.google.com/go/compute v1.12.1 // indirect
 	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
+	golang.org/x/sys v0.0.0-20220728004956-3c1f35247d10 // indirect
 	golang.org/x/text v0.4.0 // indirect
 	google.golang.org/protobuf v1.28.1 // indirect
 )

transport/grpc/dial_socketopt.go

@@ -12,14 +12,16 @@ import (
 	"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
+
+	// Copied from golang.org/x/sys/unix.TCP_USER_TIMEOUT.
+	tcpUserTimeoutOp = 0x12
 )
 
 func init() {
@@ -33,7 +35,7 @@ func dialTCPUserTimeout(ctx context.Context, addr string) (net.Conn, error) {
 		var syscallErr error
 		controlErr := c.Control(func(fd uintptr) {
 			syscallErr = syscall.SetsockoptInt(
-				int(fd), syscall.IPPROTO_TCP, unix.TCP_USER_TIMEOUT, tcpUserTimeoutMilliseconds)
+				int(fd), syscall.IPPROTO_TCP, tcpUserTimeoutOp, tcpUserTimeoutMilliseconds)
 		})
 		if syscallErr != nil {
 			return syscallErr

transport/grpc/dial_socketopt_test.go

@@ -17,7 +17,6 @@ import (
 	"time"
 
 	"golang.org/x/oauth2"
-	"golang.org/x/sys/unix"
 	"google.golang.org/api/option"
 	"google.golang.org/api/option/internaloption"
 	"google.golang.org/grpc"
@@ -78,7 +77,7 @@ func getTCPUserTimeout(conn net.Conn) (int, error) {
 	var timeout int
 	var syscalErr error
 	controlErr := rawConn.Control(func(fd uintptr) {
-		timeout, syscalErr = syscall.GetsockoptInt(int(fd), syscall.IPPROTO_TCP, unix.TCP_USER_TIMEOUT)
+		timeout, syscalErr = syscall.GetsockoptInt(int(fd), syscall.IPPROTO_TCP, tcpUserTimeoutOp)
 	})
 	if syscalErr != nil {
 		return 0, syscalErr