github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/pkg/sentry/fs/host/socket_state.go (about)

     1  // Copyright 2018 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package host
    16  
    17  import (
    18  	"fmt"
    19  
    20  	"golang.org/x/sys/unix"
    21  	"github.com/SagerNet/gvisor/pkg/fd"
    22  )
    23  
    24  // beforeSave is invoked by stateify.
    25  func (c *ConnectedEndpoint) beforeSave() {
    26  	if c.srfd < 0 {
    27  		panic("only host file descriptors provided at sentry startup can be saved")
    28  	}
    29  }
    30  
    31  // afterLoad is invoked by stateify.
    32  func (c *ConnectedEndpoint) afterLoad() {
    33  	f, err := unix.Dup(c.srfd)
    34  	if err != nil {
    35  		panic(fmt.Sprintf("failed to dup restored FD %d: %v", c.srfd, err))
    36  	}
    37  	c.file = fd.New(f)
    38  	if err := c.init(); err != nil {
    39  		panic(fmt.Sprintf("Could not restore host socket FD %d: %v", c.srfd, err))
    40  	}
    41  	c.Init()
    42  }