traefik/vendor/github.com/opencontainers/runc/libcontainer/devices/devices_unix.go
2017-03-09 13:13:02 +01:00

102 lines
2.2 KiB
Go

// +build linux freebsd
package devices
import (
"errors"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"syscall"
"github.com/opencontainers/runc/libcontainer/configs"
)
var (
ErrNotADevice = errors.New("not a device node")
)
// Testing dependencies
var (
osLstat = os.Lstat
ioutilReadDir = ioutil.ReadDir
)
// Given the path to a device and it's cgroup_permissions(which cannot be easily queried) look up the information about a linux device and return that information as a Device struct.
func DeviceFromPath(path, permissions string) (*configs.Device, error) {
fileInfo, err := osLstat(path)
if err != nil {
return nil, err
}
var (
devType rune
mode = fileInfo.Mode()
fileModePermissionBits = os.FileMode.Perm(mode)
)
switch {
case mode&os.ModeDevice == 0:
return nil, ErrNotADevice
case mode&os.ModeCharDevice != 0:
fileModePermissionBits |= syscall.S_IFCHR
devType = 'c'
default:
fileModePermissionBits |= syscall.S_IFBLK
devType = 'b'
}
stat_t, ok := fileInfo.Sys().(*syscall.Stat_t)
if !ok {
return nil, fmt.Errorf("cannot determine the device number for device %s", path)
}
devNumber := int(stat_t.Rdev)
return &configs.Device{
Type: devType,
Path: path,
Major: Major(devNumber),
Minor: Minor(devNumber),
Permissions: permissions,
FileMode: fileModePermissionBits,
Uid: stat_t.Uid,
Gid: stat_t.Gid,
}, nil
}
func HostDevices() ([]*configs.Device, error) {
return getDevices("/dev")
}
func getDevices(path string) ([]*configs.Device, error) {
files, err := ioutilReadDir(path)
if err != nil {
return nil, err
}
out := []*configs.Device{}
for _, f := range files {
switch {
case f.IsDir():
switch f.Name() {
case "pts", "shm", "fd", "mqueue":
continue
default:
sub, err := getDevices(filepath.Join(path, f.Name()))
if err != nil {
return nil, err
}
out = append(out, sub...)
continue
}
case f.Name() == "console":
continue
}
device, err := DeviceFromPath(filepath.Join(path, f.Name()), "rwm")
if err != nil {
if err == ErrNotADevice {
continue
}
return nil, err
}
out = append(out, device)
}
return out, nil
}