udev

Documentation

Index

• Constants
• func OsDiskName() (string, error)
• type MockOsDiskDetails
  • func MockDiskDetails() (MockOsDiskDetails, error)
• type Udev
  • func NewUdev() (*Udev, error)
  • func (u *Udev) NewDeviceFromNetlink(source string) (*UdevMonitor, error)
  • func (u *Udev) NewDeviceFromSysPath(sysPath string) (*UdevDevice, error)
  • func (u *Udev) NewUdevEnumerate() (*UdevEnumerate, error)
  • func (u *Udev) UnrefUdev()
• type UdevDevice
  • func (device *UdevDevice) DiskInfoFromLibudev() UdevDiskDetails
  • func (ud *UdevDevice) GetAction() string
  • func (device *UdevDevice) GetDevLinks() map[string][]string
  • func (ud *UdevDevice) GetDevnode() string
  • func (ud *UdevDevice) GetDevtype() string
  • func (ud *UdevDevice) GetPropertyValue(key string) string
  • func (ud *UdevDevice) GetSysattrValue(sysattr string) string
  • func (device *UdevDevice) GetSyspath() string
  • func (device *UdevDevice) GetUid() string
  • func (device *UdevDevice) IsDisk() bool
  • func (ud *UdevDevice) UdevDeviceUnref()
• type UdevDiskDetails
• type UdevEnumerate
  • func (ue *UdevEnumerate) AddSubsystemFilter(subSystem string) error
  • func (ue *UdevEnumerate) ListEntry() *UdevListEntry
  • func (ue *UdevEnumerate) ScanDevices() error
  • func (ue *UdevEnumerate) UnrefUdevEnumerate()
• type UdevListEntry
  • func (le *UdevListEntry) GetName() string
  • func (le *UdevListEntry) GetNextEntry() *UdevListEntry
• type UdevMonitor
  • func (um *UdevMonitor) AddSubsystemFilter(key string) error
  • func (um *UdevMonitor) EnableReceiving() error
  • func (um *UdevMonitor) GetFd() (int, error)
  • func (um *UdevMonitor) ReceiveDevice() (*UdevDevice, error)
  • func (um *UdevMonitor) UdevMonitorUnref()

Constants

const (
	NDMPrefix           = "disk-"           // NDMPrefix used as disk's uuid prefix
	UDEV_SUBSYSTEM      = "block"           // udev to filter this device type
	UDEV_SYSTEM         = "disk"            // used to filter devices other than disk which udev tracks (eg. CD ROM)
	UDEV_PATH           = "DEVPATH"         // udev attribute to get device path
	UDEV_WWN            = "ID_WWN"          // udev attribute to get device WWN number
	UDEV_SERIAL         = "ID_SERIAL_SHORT" // udev attribute to get device serial number
	UDEV_SERIAL_FULL    = "ID_SERIAL"       // udev attribute to get - separated vendor, model, serial
	UDEV_BUS            = "ID_BUS"          // udev attribute to get bus name
	UDEV_MODEL          = "ID_MODEL"        // udev attribute to get device model number
	UDEV_VENDOR         = "ID_VENDOR"       // udev attribute to get device vendor details
	UDEV_TYPE           = "ID_TYPE"         // udev attribute to get device type
	UDEV_MAJOR          = "MAJOR"           // udev attribute to get device major no
	UDEV_MINOR          = "MINOR"           // udev attribute to get device minor no
	UDEV_UUID           = "UDEV_UUID"       // ndm attribute to get device uuid
	UDEV_SYSPATH        = "UDEV_SYSPATH"    // udev attribute to get device syspath
	UDEV_ACTION         = "UDEV_ACTION"     // udev attribute to get monitor device action
	UDEV_ACTION_ADD     = "add"             // udev attribute constant for add action
	UDEV_ACTION_REMOVE  = "remove"          // udev attribute constant for remove action
	UDEV_DEVTYPE        = "DEVTYPE"         // udev attribute to get device device type ie - disk or part
	UDEV_SOURCE         = "udev"            // udev source constant
	UDEV_SYSPATH_PREFIX = "/sys/dev/block/" // udev syspath prefix
	UDEV_DEVNAME        = "DEVNAME"         // udev attribute contain disk name given by kernel
	UDEV_DEVLINKS       = "DEVLINKS"        // udev attribute contain devlinks of a disk
	BY_ID_LINK          = "by-id"           // by-path devlink contains this string
	BY_PATH_LINK        = "by-path"         // by-path devlink contains this string
	LINK_ID_INDEX       = 4                 // this is used to get link index from dev link
)

Functions

func OsDiskName

func OsDiskName() (string, error)

OsDiskName returns os disk name given by kernel

Types

type MockOsDiskDetails

type MockOsDiskDetails struct {
	OsDiskName     string
	DevType        string
	DevNode        string
	Size           string
	SysPath        string
	Model          string
	Serial         string
	Vendor         string
	Wwn            string
	Uid            string
	ByIdDevLinks   []string
	ByPathDevLinks []string
}

MockOsDiskDetails struct contain different attribute of os disk.

func MockDiskDetails

func MockDiskDetails() (MockOsDiskDetails, error)

MockDiskDetails returns os disk details which is used in unit test.

type Udev

type Udev struct {
	// contains filtered or unexported fields
}

Udev wraps a libudev udev struct

func NewUdev

func NewUdev() (*Udev, error)

NewUdev is a function and which returns a pointer to a new Udev

func (*Udev) NewDeviceFromNetlink

func (u *Udev) NewDeviceFromNetlink(source string) (*UdevMonitor, error)

NewDeviceFromNetlink use newUdeviceMonitor() and use returns UdevMonitor pointer in success The function returns nil on failure it can monitor udev or kernel as source.

func (*Udev) NewDeviceFromSysPath

func (u *Udev) NewDeviceFromSysPath(sysPath string) (*UdevDevice, error)

NewDeviceFromSysPath identify the block device currently attached to the system at given sysPath and returns that pointer of C udev_device structure. The caller can query all(available) the disk properties using returned C udev_device structure.

func (*Udev) NewUdevEnumerate

func (u *Udev) NewUdevEnumerate() (*UdevEnumerate, error)

NewUdevEnumerate returns a pointer to a Udevenumerate

func (*Udev) UnrefUdev

func (u *Udev) UnrefUdev()

UnrefUdev frees udev structure.

type UdevDevice

type UdevDevice struct {
	// contains filtered or unexported fields
}

UdevDevice wraps a libudev device object

func (*UdevDevice) DiskInfoFromLibudev

func (device *UdevDevice) DiskInfoFromLibudev() UdevDiskDetails

DiskInfoFromLibudev returns disk attribute extracted using libudev apicalls.

func (*UdevDevice) GetAction

func (ud *UdevDevice) GetAction() string

GetAction returns device action when it is monitored. It can be add,remove,online,offline,change

func (*UdevDevice) GetDevLinks

func (device *UdevDevice) GetDevLinks() map[string][]string

GetDevLinks returns syspath of a disk using syspath we can fell details in diskInfo struct using udev probe

func (*UdevDevice) GetDevnode

func (ud *UdevDevice) GetDevnode() string

GetDevnode returns the device node file name belonging to the udev device. The path is an absolute path, and starts with the device directory.

func (*UdevDevice) GetDevtype

func (ud *UdevDevice) GetDevtype() string

GetDevtype returns the devtype string of the udev device.

func (*UdevDevice) GetPropertyValue

func (ud *UdevDevice) GetPropertyValue(key string) string

GetPropertyValue retrieves the value of a device property

func (*UdevDevice) GetSysattrValue

func (ud *UdevDevice) GetSysattrValue(sysattr string) string

GetSysattrValue retrieves the content of a sys attribute file returns an empty string if there is no sys attribute value. The retrieved value is cached in the device. Repeated calls will return the same value and not open the attribute again.

func (*UdevDevice) GetSyspath

func (device *UdevDevice) GetSyspath() string

GetSyspath returns syspath of a disk using syspath we can fell details in diskInfo struct using udev probe

func (*UdevDevice) GetUid

func (device *UdevDevice) GetUid() string

GetUid returns unique id for the disk block device

func (*UdevDevice) IsDisk

func (device *UdevDevice) IsDisk() bool

IsDisk returns true if device is a disk

func (*UdevDevice) UdevDeviceUnref

func (ud *UdevDevice) UdevDeviceUnref()

UdevDeviceUnref frees udev_device structure.

type UdevDiskDetails

type UdevDiskDetails struct {
	Model          string   // Model is Model of disk.
	Serial         string   // Serial is Serial of a disk.
	Vendor         string   // Vendor is Vendor of a disk.
	Path           string   // Path is Path of a disk.
	ByIdDevLinks   []string // ByIdDevLinks contains by-id devlinks
	ByPathDevLinks []string // ByPathDevLinks contains by-path devlinks
}

UdevDiskDetails struct contain different attribute of disk.

type UdevEnumerate

type UdevEnumerate struct {
	// contains filtered or unexported fields
}

UdevEnumerate wraps a libudev udev_enumerate object

func (*UdevEnumerate) AddSubsystemFilter

func (ue *UdevEnumerate) AddSubsystemFilter(subSystem string) error

AddSubsystemFilter adds filter in UdeviceMon struct. This filter is efficiently executed inside kernel, and libudev subscribers will usually not be woken up for devices which do not match.

func (*UdevEnumerate) ListEntry

func (ue *UdevEnumerate) ListEntry() *UdevListEntry

ListEntry returns UdevListEntry struct from which we can get device.

func (*UdevEnumerate) ScanDevices

func (ue *UdevEnumerate) ScanDevices() error

ScanDevices scan devices in system and returns list of devices present in system

func (*UdevEnumerate) UnrefUdevEnumerate

func (ue *UdevEnumerate) UnrefUdevEnumerate()

UnrefUdevEnumerate frees udev_enumerate structure.

type UdevListEntry

type UdevListEntry struct {
	// contains filtered or unexported fields
}

UdevListEntry wraps a libudev udev_list_entry object

func (*UdevListEntry) GetName

func (le *UdevListEntry) GetName() string

GetName return Udevice syspath.

func (*UdevListEntry) GetNextEntry

func (le *UdevListEntry) GetNextEntry() *UdevListEntry

GetNextEntry returns UdevListEntry struct if next device is present else it returns nil pointer.

type UdevMonitor

type UdevMonitor struct {
	// contains filtered or unexported fields
}

UdevMonitor wraps a libudev monitor device object

func (*UdevMonitor) AddSubsystemFilter

func (um *UdevMonitor) AddSubsystemFilter(key string) error

AddSubsystemFilter adds subsystem filter in UdevMonitor struct. This filter is efficiently executed inside kernel, and libudev subscribers will usually not be woken up for devices which do not match.

func (*UdevMonitor) EnableReceiving

func (um *UdevMonitor) EnableReceiving() error

EnableReceiving binds udev_monitor socket to event source.

func (*UdevMonitor) GetFd

func (um *UdevMonitor) GetFd() (int, error)

GetFd retrieves socket file descriptor associated with monitor.

func (*UdevMonitor) ReceiveDevice

func (um *UdevMonitor) ReceiveDevice() (*UdevDevice, error)

ReceiveDevice receives data from udev monitor socket, allocate a new udev device, fill in received data, and return Udevice struct.

func (*UdevMonitor) UdevMonitorUnref

func (um *UdevMonitor) UdevMonitorUnref()

UdevMonitorUnref frees udev monitor structure.