volume/mounts/windows_parser.go
package mounts // import "github.com/docker/docker/volume/mounts"
import (
"errors"
"fmt"
"os"
"path/filepath"
"regexp"
"runtime"
"strings"
"github.com/docker/docker/api/types/mount"
"github.com/docker/docker/pkg/stringid"
)
// NewWindowsParser creates a parser with Windows semantics.
func NewWindowsParser() Parser {
return &windowsParser{
fi: defaultFileInfoProvider{},
}
}
type windowsParser struct {
fi fileInfoProvider
}
const (
// Spec should be in the format [source:]destination[:mode]
//
// Examples: c:\foo bar:d:rw
// c:\foo:d:\bar
// myname:d:
// d:\
//
// Explanation of this regex! Thanks @thaJeztah on IRC and gist for help. See
// https://gist.github.com/thaJeztah/6185659e4978789fb2b2. A good place to
// test is https://regex-golang.appspot.com/assets/html/index.html
//
// Useful link for referencing named capturing groups:
// http://stackoverflow.com/questions/20750843/using-named-matches-from-go-regex
//
// There are three match groups: source, destination and mode.
//
// rxHostDir is the first option of a source
rxHostDir = `(?:\\\\\?\\)?[a-z]:[\\/](?:[^\\/:*?"<>|\r\n]+[\\/]?)*`
// rxName is the second option of a source
rxName = `[^\\/:*?"<>|\r\n]+`
// RXReservedNames are reserved names not possible on Windows
rxReservedNames = `(con|prn|nul|aux|com[1-9]|lpt[1-9])`
// rxPipe is a named path pipe (starts with `\\.\pipe\`, possibly with / instead of \)
rxPipe = `[/\\]{2}.[/\\]pipe[/\\][^:*?"<>|\r\n]+`
// rxSource is the combined possibilities for a source
rxSource = `((?P<source>((` + rxHostDir + `)|(` + rxName + `)|(` + rxPipe + `))):)?`
// Source. Can be either a host directory, a name, or omitted:
// HostDir:
// - Essentially using the folder solution from
// https://www.safaribooksonline.com/library/view/regular-expressions-cookbook/9781449327453/ch08s18.html
// but adding case insensitivity.
// - Must be an absolute path such as c:\path
// - Can include spaces such as `c:\program files`
// - And then followed by a colon which is not in the capture group
// - And can be optional
// Name:
// - Must not contain invalid NTFS filename characters (https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx)
// - And then followed by a colon which is not in the capture group
// - And can be optional
// rxDestination is the regex expression for the mount destination
rxDestination = `(?P<destination>((?:\\\\\?\\)?([a-z]):((?:[\\/][^\\/:*?"<>\r\n]+)*[\\/]?))|(` + rxPipe + `))`
// rxMode is the regex expression for the mode of the mount
// Mode (optional):
// - Hopefully self explanatory in comparison to above regex's.
// - Colon is not in the capture group
rxMode = `(:(?P<mode>(?i)ro|rw))?`
)
var (
volumeNameRegexp = regexp.MustCompile(`^` + rxName + `$`)
reservedNameRegexp = regexp.MustCompile(`^` + rxReservedNames + `$`)
hostDirRegexp = regexp.MustCompile(`^` + rxHostDir + `$`)
mountDestinationRegexp = regexp.MustCompile(`^` + rxDestination + `$`)
windowsSplitRawSpecRegexp = regexp.MustCompile(`^` + rxSource + rxDestination + rxMode + `$`)
)
type mountValidator func(mnt *mount.Mount) error
func (p *windowsParser) splitRawSpec(raw string, splitRegexp *regexp.Regexp) ([]string, error) {
match := splitRegexp.FindStringSubmatch(strings.ToLower(raw))
if len(match) == 0 {
return nil, errInvalidSpec(raw)
}
var split []string
matchgroups := make(map[string]string)
// Pull out the sub expressions from the named capture groups
for i, name := range splitRegexp.SubexpNames() {
matchgroups[name] = strings.ToLower(match[i])
}
if source, exists := matchgroups["source"]; exists {
if source != "" {
split = append(split, source)
}
}
if destination, exists := matchgroups["destination"]; exists {
if destination != "" {
split = append(split, destination)
}
}
if mode, exists := matchgroups["mode"]; exists {
if mode != "" {
split = append(split, mode)
}
}
// Fix #26329. If the destination appears to be a file, and the source is null,
// it may be because we've fallen through the possible naming regex and hit a
// situation where the user intention was to map a file into a container through
// a local volume, but this is not supported by the platform.
if matchgroups["source"] == "" && matchgroups["destination"] != "" {
if volumeNameRegexp.MatchString(matchgroups["destination"]) {
if reservedNameRegexp.MatchString(matchgroups["destination"]) {
return nil, fmt.Errorf("volume name %q cannot be a reserved word for Windows filenames", matchgroups["destination"])
}
} else {
exists, isDir, _ := p.fi.fileInfo(matchgroups["destination"])
if exists && !isDir {
return nil, fmt.Errorf("file '%s' cannot be mapped. Only directories can be mapped on this platform", matchgroups["destination"])
}
}
}
return split, nil
}
func windowsValidMountMode(mode string) bool {
if mode == "" {
return true
}
// TODO should windows mounts produce an error if any mode was provided (they're a no-op on windows)
return rwModes[strings.ToLower(mode)]
}
func windowsValidateNotRoot(p string) error {
p = strings.ToLower(strings.ReplaceAll(p, `/`, `\`))
if p == "c:" || p == `c:\` {
return fmt.Errorf("destination path cannot be `c:` or `c:\\`: %v", p)
}
return nil
}
var windowsValidators mountValidator = func(m *mount.Mount) error {
if err := windowsValidateNotRoot(m.Target); err != nil {
return err
}
if !mountDestinationRegexp.MatchString(strings.ToLower(m.Target)) {
return fmt.Errorf("invalid mount path: '%s'", m.Target)
}
return nil
}
func windowsValidateAbsolute(p string) error {
if !mountDestinationRegexp.MatchString(strings.ToLower(p)) {
return fmt.Errorf("invalid mount path: '%s' mount path must be absolute", p)
}
return nil
}
func windowsDetectMountType(p string) mount.Type {
if strings.HasPrefix(p, `\\.\pipe\`) {
return mount.TypeNamedPipe
} else if hostDirRegexp.MatchString(p) {
return mount.TypeBind
} else {
return mount.TypeVolume
}
}
func (p *windowsParser) ReadWrite(mode string) bool {
return strings.ToLower(mode) != "ro"
}
// ValidateVolumeName checks a volume name in a platform specific manner.
func (p *windowsParser) ValidateVolumeName(name string) error {
if !volumeNameRegexp.MatchString(name) {
return errors.New("invalid volume name")
}
if reservedNameRegexp.MatchString(name) {
return fmt.Errorf("volume name %q cannot be a reserved word for Windows filenames", name)
}
return nil
}
func (p *windowsParser) ValidateMountConfig(mnt *mount.Mount) error {
return p.validateMountConfigReg(mnt, windowsValidators)
}
type fileInfoProvider interface {
fileInfo(path string) (exist, isDir bool, err error)
}
type defaultFileInfoProvider struct{}
func (defaultFileInfoProvider) fileInfo(path string) (exist, isDir bool, err error) {
fi, err := os.Stat(path)
if err != nil {
if !os.IsNotExist(err) {
return false, false, err
}
return false, false, nil
}
return true, fi.IsDir(), nil
}
func (p *windowsParser) validateMountConfigReg(mnt *mount.Mount, additionalValidators ...mountValidator) error {
if len(mnt.Target) == 0 {
return &errMountConfig{mnt, errMissingField("Target")}
}
for _, v := range additionalValidators {
if err := v(mnt); err != nil {
return &errMountConfig{mnt, err}
}
}
switch mnt.Type {
case mount.TypeBind:
if len(mnt.Source) == 0 {
return &errMountConfig{mnt, errMissingField("Source")}
}
// Don't error out just because the propagation mode is not supported on the platform
if opts := mnt.BindOptions; opts != nil {
if len(opts.Propagation) > 0 {
return &errMountConfig{mnt, fmt.Errorf("invalid propagation mode: %s", opts.Propagation)}
}
}
if mnt.VolumeOptions != nil {
return &errMountConfig{mnt, errExtraField("VolumeOptions")}
}
if err := windowsValidateAbsolute(mnt.Source); err != nil {
return &errMountConfig{mnt, err}
}
exists, isdir, err := p.fi.fileInfo(mnt.Source)
if err != nil {
return &errMountConfig{mnt, err}
}
if !exists {
return &errMountConfig{mnt, errBindSourceDoesNotExist(mnt.Source)}
}
if !isdir {
return &errMountConfig{mnt, fmt.Errorf("source path must be a directory")}
}
case mount.TypeVolume:
if mnt.BindOptions != nil {
return &errMountConfig{mnt, errExtraField("BindOptions")}
}
anonymousVolume := len(mnt.Source) == 0
if mnt.VolumeOptions != nil && mnt.VolumeOptions.Subpath != "" {
if anonymousVolume {
return errAnonymousVolumeWithSubpath
}
// Check if path is relative but without any back traversals
if !filepath.IsLocal(mnt.VolumeOptions.Subpath) {
return &errMountConfig{mnt, errInvalidSubpath}
}
}
if anonymousVolume && mnt.ReadOnly {
return &errMountConfig{mnt, fmt.Errorf("must not set ReadOnly mode when using anonymous volumes")}
}
if len(mnt.Source) != 0 {
if err := p.ValidateVolumeName(mnt.Source); err != nil {
return &errMountConfig{mnt, err}
}
}
case mount.TypeNamedPipe:
if len(mnt.Source) == 0 {
return &errMountConfig{mnt, errMissingField("Source")}
}
if mnt.BindOptions != nil {
return &errMountConfig{mnt, errExtraField("BindOptions")}
}
if mnt.ReadOnly {
return &errMountConfig{mnt, errExtraField("ReadOnly")}
}
if windowsDetectMountType(mnt.Source) != mount.TypeNamedPipe {
return &errMountConfig{mnt, fmt.Errorf("'%s' is not a valid pipe path", mnt.Source)}
}
if windowsDetectMountType(mnt.Target) != mount.TypeNamedPipe {
return &errMountConfig{mnt, fmt.Errorf("'%s' is not a valid pipe path", mnt.Target)}
}
default:
return &errMountConfig{mnt, errors.New("mount type unknown")}
}
return nil
}
func (p *windowsParser) ParseMountRaw(raw, volumeDriver string) (*MountPoint, error) {
arr, err := p.splitRawSpec(raw, windowsSplitRawSpecRegexp)
if err != nil {
return nil, err
}
return p.parseMount(arr, raw, volumeDriver, true, windowsValidators)
}
func (p *windowsParser) parseMount(arr []string, raw, volumeDriver string, convertTargetToBackslash bool, additionalValidators ...mountValidator) (*MountPoint, error) {
var spec mount.Mount
var mode string
switch len(arr) {
case 1:
// Just a destination path in the container
spec.Target = arr[0]
case 2:
if windowsValidMountMode(arr[1]) {
// Destination + Mode is not a valid volume - volumes
// cannot include a mode. e.g. /foo:rw
return nil, errInvalidSpec(raw)
}
// Host Source Path or Name + Destination
spec.Source = strings.ReplaceAll(arr[0], `/`, `\`)
spec.Target = arr[1]
case 3:
// HostSourcePath+DestinationPath+Mode
spec.Source = strings.ReplaceAll(arr[0], `/`, `\`)
spec.Target = arr[1]
mode = arr[2]
default:
return nil, errInvalidSpec(raw)
}
if convertTargetToBackslash {
spec.Target = strings.ReplaceAll(spec.Target, `/`, `\`)
}
if !windowsValidMountMode(mode) {
return nil, errInvalidMode(mode)
}
spec.Type = windowsDetectMountType(spec.Source)
spec.ReadOnly = !p.ReadWrite(mode)
// cannot assume that if a volume driver is passed in that we should set it
if volumeDriver != "" && spec.Type == mount.TypeVolume {
spec.VolumeOptions = &mount.VolumeOptions{
DriverConfig: &mount.Driver{Name: volumeDriver},
}
}
if copyData, isSet := getCopyMode(mode, p.DefaultCopyMode()); isSet {
if spec.VolumeOptions == nil {
spec.VolumeOptions = &mount.VolumeOptions{}
}
spec.VolumeOptions.NoCopy = !copyData
}
mp, err := p.parseMountSpec(spec, convertTargetToBackslash, additionalValidators...)
if mp != nil {
mp.Mode = mode
}
if err != nil {
err = fmt.Errorf("%v: %v", errInvalidSpec(raw), err)
}
return mp, err
}
func (p *windowsParser) ParseMountSpec(cfg mount.Mount) (*MountPoint, error) {
return p.parseMountSpec(cfg, true, windowsValidators)
}
func (p *windowsParser) parseMountSpec(cfg mount.Mount, convertTargetToBackslash bool, additionalValidators ...mountValidator) (*MountPoint, error) {
if err := p.validateMountConfigReg(&cfg, additionalValidators...); err != nil {
return nil, err
}
mp := &MountPoint{
RW: !cfg.ReadOnly,
Destination: cfg.Target,
Type: cfg.Type,
Spec: cfg,
}
if convertTargetToBackslash {
mp.Destination = strings.ReplaceAll(cfg.Target, `/`, `\`)
}
switch cfg.Type {
case mount.TypeVolume:
if cfg.Source == "" {
mp.Name = stringid.GenerateRandomID()
} else {
mp.Name = cfg.Source
}
mp.CopyData = p.DefaultCopyMode()
if cfg.VolumeOptions != nil {
if cfg.VolumeOptions.DriverConfig != nil {
mp.Driver = cfg.VolumeOptions.DriverConfig.Name
}
if cfg.VolumeOptions.NoCopy {
mp.CopyData = false
}
}
case mount.TypeBind:
mp.Source = strings.ReplaceAll(cfg.Source, `/`, `\`)
case mount.TypeNamedPipe:
mp.Source = strings.ReplaceAll(cfg.Source, `/`, `\`)
}
// cleanup trailing `\` except for paths like `c:\`
if len(mp.Source) > 3 && mp.Source[len(mp.Source)-1] == '\\' {
mp.Source = mp.Source[:len(mp.Source)-1]
}
if len(mp.Destination) > 3 && mp.Destination[len(mp.Destination)-1] == '\\' {
mp.Destination = mp.Destination[:len(mp.Destination)-1]
}
return mp, nil
}
func (p *windowsParser) ParseVolumesFrom(spec string) (string, string, error) {
if len(spec) == 0 {
return "", "", fmt.Errorf("volumes-from specification cannot be an empty string")
}
id, mode, _ := strings.Cut(spec, ":")
if mode == "" {
return id, "rw", nil
}
if !windowsValidMountMode(mode) {
return "", "", errInvalidMode(mode)
}
// Do not allow copy modes on volumes-from
if _, isSet := getCopyMode(mode, p.DefaultCopyMode()); isSet {
return "", "", errInvalidMode(mode)
}
return id, mode, nil
}
func (p *windowsParser) DefaultPropagationMode() mount.Propagation {
return ""
}
func (p *windowsParser) ConvertTmpfsOptions(opt *mount.TmpfsOptions, readOnly bool) (string, error) {
return "", fmt.Errorf("%s does not support tmpfs", runtime.GOOS)
}
func (p *windowsParser) DefaultCopyMode() bool {
return false
}
func (p *windowsParser) IsBackwardCompatible(m *MountPoint) bool {
return false
}
func (p *windowsParser) ValidateTmpfsMountDestination(dest string) error {
return errors.New("platform does not support tmpfs")
}
func (p *windowsParser) HasResource(m *MountPoint, absolutePath string) bool {
return false
}