ip

Documentation

Index

• Variables
• func IsErrAllocated(err error) bool
• type ErrNotInRange
  • func (e *ErrNotInRange) Error() string
• type Interface
• type Range
  • func NewAllocatorCIDRRange(cidr *net.IPNet, allocatorFactory allocator.AllocatorFactory) (*Range, error)
  • func NewCIDRRange(cidr *net.IPNet) (*Range, error)
  • func (r *Range) Allocate(ip net.IP) error
  • func (r *Range) AllocateNext() (net.IP, error)
  • func (r *Range) CIDR() net.IPNet
  • func (r *Range) ForEach(fn func(net.IP))
  • func (r *Range) Free() int
  • func (r *Range) Has(ip net.IP) bool
  • func (r *Range) Release(ip net.IP)
  • func (r *Range) Reserved(ip net.IP) bool
  • func (r *Range) Used() int

Variables

var (
	ErrFull      = errors.New("range is full")
	ErrAllocated = errors.New("provided IP is already allocated")
)

Functions

func IsErrAllocated

func IsErrAllocated(err error) bool

IsErrAllocated returns true if err is of type ErrAllocated

Types

type ErrNotInRange

type ErrNotInRange struct {
	ValidRange string
}

func (*ErrNotInRange) Error

func (e *ErrNotInRange) Error() string

type Interface

type Interface interface {
	Allocate(net.IP) error
	AllocateNext() (net.IP, error)
	Release(net.IP)
	ForEach(func(net.IP))
	CIDR() net.IPNet
	Has(ip net.IP) bool
	Reserved(ip net.IP) bool
}

Interface manages the allocation of IP addresses out of a range. Interface should be threadsafe.

type Range

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

Range is a contiguous block of IPs that can be allocated atomically.

The internal structure of the range is:

For CIDR 10.0.0.0/24
254 addresses usable out of 256 total (minus base and broadcast IPs)
  The number of usable addresses is r.max

CIDR base IP          CIDR broadcast IP
10.0.0.0                     10.0.0.255
|                                     |
0 1 2 3 4 5 ...         ... 253 254 255
  |                              |
r.base                     r.base + r.max
  |                              |
offset #0 of r.allocated   last offset of r.allocated

func NewAllocatorCIDRRange

func NewAllocatorCIDRRange(cidr *net.IPNet, allocatorFactory allocator.AllocatorFactory) (*Range, error)

NewAllocatorCIDRRange creates a Range over a net.IPNet, calling allocatorFactory to construct the backing store.

func NewCIDRRange

func NewCIDRRange(cidr *net.IPNet) (*Range, error)

NewCIDRRange is a helper that wraps NewAllocatorCIDRRange, for creating a range backed by an in-memory store.

func (*Range) Allocate

func (r *Range) Allocate(ip net.IP) error

Allocate attempts to reserve the provided IP. ErrNotInRange or ErrAllocated will be returned if the IP is not valid for this range or has already been reserved. ErrFull will be returned if there are no addresses left.

func (*Range) AllocateNext

func (r *Range) AllocateNext() (net.IP, error)

AllocateNext reserves one of the IPs from the pool. ErrFull may be returned if there are no addresses left.

func (*Range) CIDR

func (r *Range) CIDR() net.IPNet

CIDR returns the CIDR covered by the range.

func (*Range) ForEach

func (r *Range) ForEach(fn func(net.IP))

ForEach calls the provided function for each allocated IP.

func (*Range) Free

func (r *Range) Free() int

Free returns the count of IP addresses left in the range.

func (*Range) Has

func (r *Range) Has(ip net.IP) bool

Has returns true if the provided IP is already allocated and a call to Allocate(ip) would fail with ErrAllocated.

func (*Range) Release

func (r *Range) Release(ip net.IP)

Release releases the IP back to the pool. Releasing an unallocated IP or an IP out of the range is a no-op and returns no error.

func (*Range) Reserved

func (r *Range) Reserved(ip net.IP) bool

Reserved returns true if the provided IP can't be allocated. This is *only* true for the network and broadcast addresses.

func (*Range) Used

func (r *Range) Used() int

Used returns the count of IP addresses used in the range.