Update cancel context usage

transport/v2raygrpc/conn.go

@@ -1,12 +1,12 @@
 package v2raygrpc
 
 import (
-	"context"
 	"net"
 	"os"
 	"time"
 
 	"github.com/sagernet/sing-box/common/baderror"
+	"github.com/sagernet/sing/common"
 	"github.com/sagernet/sing/common/rw"
 )
 
@@ -14,11 +14,11 @@ var _ net.Conn = (*GRPCConn)(nil)
 
 type GRPCConn struct {
 	GunService
-	cancel context.CancelFunc
+	cancel common.ContextCancelCauseFunc
 	cache  []byte
 }
 
-func NewGRPCConn(service GunService, cancel context.CancelFunc) *GRPCConn {
+func NewGRPCConn(service GunService, cancel common.ContextCancelCauseFunc) *GRPCConn {
 	if client, isClient := service.(GunService_TunClient); isClient {
 		service = &clientConnWrapper{client}
 	}
@@ -37,6 +37,7 @@ func (c *GRPCConn) Read(b []byte) (n int, err error) {
 	hunk, err := c.Recv()
 	err = baderror.WrapGRPC(err)
 	if err != nil {
+		c.cancel(err)
 		return
 	}
 	n = copy(b, hunk.Data)
@@ -49,13 +50,14 @@ func (c *GRPCConn) Read(b []byte) (n int, err error) {
 func (c *GRPCConn) Write(b []byte) (n int, err error) {
 	err = baderror.WrapGRPC(c.Send(&Hunk{Data: b}))
 	if err != nil {
+		c.cancel(err)
 		return
 	}
 	return len(b), nil
 }
 
 func (c *GRPCConn) Close() error {
-	c.cancel()
+	c.cancel(net.ErrClosed)
 	return nil
 }