perkeep/third_party/code.google.com/p/rsc/fuse/mount_linux.go

68 lines
1.8 KiB
Go

// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package fuse
import (
"fmt"
"net"
"os"
"os/exec"
"syscall"
)
func mount(dir string) (fusefd int, errmsg string) {
fds, err := syscall.Socketpair(syscall.AF_FILE, syscall.SOCK_STREAM, 0)
if err != nil {
return -1, fmt.Sprintf("socketpair error: %v", err)
}
defer syscall.Close(fds[0])
defer syscall.Close(fds[1])
cmd := exec.Command("/bin/fusermount", "--", dir)
cmd.Env = append(os.Environ(), "_FUSE_COMMFD=3")
writeFile := os.NewFile(uintptr(fds[0]), "fusermount-child-writes")
defer writeFile.Close()
cmd.ExtraFiles = []*os.File{writeFile}
out, err := cmd.CombinedOutput()
if len(out) > 0 || err != nil {
return -1, fmt.Sprintf("fusermount: %q, %v", out, err)
}
readFile := os.NewFile(uintptr(fds[1]), "fusermount-parent-reads")
defer readFile.Close()
c, err := net.FileConn(readFile)
if err != nil {
return -1, fmt.Sprintf("FileConn from fusermount socket: %v", err)
}
defer c.Close()
uc, ok := c.(*net.UnixConn)
if !ok {
return -1, fmt.Sprintf("unexpected FileConn type; expected UnixConn, got %T", c)
}
buf := make([]byte, 32) // expect 1 byte
oob := make([]byte, 32) // expect 24 bytes
_, oobn, _, _, err := uc.ReadMsgUnix(buf, oob)
scms, err := syscall.ParseSocketControlMessage(oob[:oobn])
if err != nil {
return -1, fmt.Sprintf("ParseSocketControlMessage: %v", err)
}
if len(scms) != 1 {
return -1, fmt.Sprintf("expected 1 SocketControlMessage; got scms = %#v", scms)
}
scm := scms[0]
gotFds, err := syscall.ParseUnixRights(&scm)
if err != nil {
return -1, fmt.Sprintf("syscall.ParseUnixRights: %v", err)
}
if len(gotFds) != 1 {
return -1, fmt.Sprintf("wanted 1 fd; got %#v", gotFds)
}
return gotFds[0], ""
}