containerd/oci/utils_unix.go

138 lines
3.2 KiB
Go

// +build !windows
/*
Copyright The containerd Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package oci
import (
"io/ioutil"
"os"
"path/filepath"
specs "github.com/opencontainers/runtime-spec/specs-go"
"github.com/pkg/errors"
"golang.org/x/sys/unix"
)
var errNotADevice = errors.New("not a device node")
// HostDevices returns all devices that can be found under /dev directory.
func HostDevices() ([]specs.LinuxDevice, error) {
return getDevices("/dev", "")
}
func getDevices(path, containerPath string) ([]specs.LinuxDevice, error) {
stat, err := os.Stat(path)
if err != nil {
return nil, errors.Wrap(err, "error stating device path")
}
if !stat.IsDir() {
dev, err := deviceFromPath(path)
if err != nil {
return nil, err
}
if containerPath != "" {
dev.Path = containerPath
}
return []specs.LinuxDevice{*dev}, nil
}
files, err := ioutil.ReadDir(path)
if err != nil {
return nil, err
}
var out []specs.LinuxDevice
for _, f := range files {
switch {
case f.IsDir():
switch f.Name() {
// ".lxc" & ".lxd-mounts" added to address https://github.com/lxc/lxd/issues/2825
// ".udev" added to address https://github.com/opencontainers/runc/issues/2093
case "pts", "shm", "fd", "mqueue", ".lxc", ".lxd-mounts", ".udev":
continue
default:
var cp string
if containerPath != "" {
cp = filepath.Join(containerPath, filepath.Base(f.Name()))
}
sub, err := getDevices(filepath.Join(path, f.Name()), cp)
if err != nil {
return nil, err
}
out = append(out, sub...)
continue
}
case f.Name() == "console":
continue
}
device, err := deviceFromPath(filepath.Join(path, f.Name()))
if err != nil {
if err == errNotADevice {
continue
}
if os.IsNotExist(err) {
continue
}
return nil, err
}
if containerPath != "" {
device.Path = filepath.Join(containerPath, filepath.Base(f.Name()))
}
out = append(out, *device)
}
return out, nil
}
func deviceFromPath(path string) (*specs.LinuxDevice, error) {
var stat unix.Stat_t
if err := unix.Lstat(path, &stat); err != nil {
return nil, err
}
var (
devNumber = uint64(stat.Rdev) //nolint: unconvert // the type is 32bit on mips.
major = unix.Major(devNumber)
minor = unix.Minor(devNumber)
)
if major == 0 {
return nil, errNotADevice
}
var (
devType string
mode = stat.Mode
)
switch {
case mode&unix.S_IFBLK == unix.S_IFBLK:
devType = "b"
case mode&unix.S_IFCHR == unix.S_IFCHR:
devType = "c"
}
fm := os.FileMode(mode &^ unix.S_IFMT)
return &specs.LinuxDevice{
Type: devType,
Path: path,
Major: int64(major),
Minor: int64(minor),
FileMode: &fm,
UID: &stat.Uid,
GID: &stat.Gid,
}, nil
}