devices

Documentation

Index

• Constants
• Variables
• func CreateDevicesFromHost(rootfs string) error
• type Device
  • func DeviceFromPath(path, permissions string) (*Device, error)
  • func GetDevices(path string) ([]*Device, error)
  • func HostDevices() ([]*Device, error)
• type DevicePermissions
  • func (p DevicePermissions) Difference(o DevicePermissions) DevicePermissions
  • func (p DevicePermissions) Intersection(o DevicePermissions) DevicePermissions
  • func (p DevicePermissions) IsEmpty() bool
  • func (p DevicePermissions) IsValid() bool
  • func (p DevicePermissions) Union(o DevicePermissions) DevicePermissions
• type DeviceRule
  • func (d *DeviceRule) CgroupString() string
  • func (d *DeviceRule) Mkdev() (uint64, error)
• type DeviceType
  • func (t DeviceType) CanCgroup() bool
  • func (t DeviceType) CanMknod() bool
  • func (t DeviceType) IsValid() bool

Constants

const (
	Wildcard = -1
)

Variables

var (
	// ErrNotADevice denotes that a file is not a valid linux device.
	ErrNotADevice = errors.New("not a device node")
)

Functions

func CreateDevicesFromHost

func CreateDevicesFromHost(rootfs string) error

Types

type Device

type Device struct {
	DeviceRule

	// Path to the device.
	Path string `json:"path"`

	// FileMode permission bits for the device.
	FileMode os.FileMode `json:"file_mode"`

	// Uid of the device.
	Uid uint32 `json:"uid"`

	// Gid of the device.
	Gid uint32 `json:"gid"`
}

func DeviceFromPath

func DeviceFromPath(path, permissions string) (*Device, error)

Given the path to a device and its cgroup_permissions(which cannot be easily queried) look up the information about a linux device and return that information as a Device struct.

func GetDevices

func GetDevices(path string) ([]*Device, error)

GetDevices recursively traverses a directory specified by path and returns all devices found there.

func HostDevices

func HostDevices() ([]*Device, error)

HostDevices returns all devices that can be found under /dev directory.

type DevicePermissions

type DevicePermissions string

DevicePermissions is a cgroupv1-style string to represent device access. It has to be a string for backward compatibility reasons, hence why it has methods to do set operations.

func (DevicePermissions) Difference

func (p DevicePermissions) Difference(o DevicePermissions) DevicePermissions

Difference returns the set difference of the two sets of DevicePermissions. In set notation, A.Difference(B) gives you A\B.

func (DevicePermissions) Intersection

func (p DevicePermissions) Intersection(o DevicePermissions) DevicePermissions

Intersection computes the intersection of the two sets of DevicePermissions.

func (DevicePermissions) IsEmpty

func (p DevicePermissions) IsEmpty() bool

IsEmpty returns whether the set of permissions in a DevicePermissions is empty.

func (DevicePermissions) IsValid

func (p DevicePermissions) IsValid() bool

IsValid returns whether the set of permissions is a subset of valid permissions (namely, {r,w,m}).

func (DevicePermissions) Union

func (p DevicePermissions) Union(o DevicePermissions) DevicePermissions

Union returns the union of the two sets of DevicePermissions.

type DeviceRule

type DeviceRule struct {
	// Type of device ('c' for char, 'b' for block). If set to 'a', this rule
	// acts as a wildcard and all fields other than Allow are ignored.
	Type DeviceType `json:"type"`

	// Major is the device's major number.
	Major int64 `json:"major"`

	// Minor is the device's minor number.
	Minor int64 `json:"minor"`

	// Permissions is the set of permissions that this rule applies to (in the
	// cgroupv1 format -- any combination of "rwm").
	Permissions DevicePermissions `json:"permissions"`

	// Allow specifies whether this rule is allowed.
	Allow bool `json:"allow"`
}

func (*DeviceRule) CgroupString

func (d *DeviceRule) CgroupString() string

func (*DeviceRule) Mkdev

func (d *DeviceRule) Mkdev() (uint64, error)

type DeviceType

type DeviceType rune

const (
	WildcardDevice DeviceType = 'a'
	BlockDevice    DeviceType = 'b'
	CharDevice     DeviceType = 'c' // or 'u'
	FifoDevice     DeviceType = 'p'
)

func (DeviceType) CanCgroup

func (t DeviceType) CanCgroup() bool

func (DeviceType) CanMknod

func (t DeviceType) CanMknod() bool

func (DeviceType) IsValid

func (t DeviceType) IsValid() bool