subnet

Documentation

Overview

Package subnet contains functions for finding available subnets

Index

• func CoveringCIDRs(ips []net.IP) []*net.IPNet
• func Covers(a, b *net.IPNet) bool
• func Equal(a, b *net.IPNet) bool
• func Partition(subnets []*net.IPNet, filter func(int, *net.IPNet) bool) (matched, notMatched []*net.IPNet)
• func Unique(subnets []*net.IPNet) []*net.IPNet
• type Bitfield256
  • func (b *Bitfield256) ClearBit(bv byte)
  • func (b *Bitfield256) Equals(other *Bitfield256) bool
  • func (b *Bitfield256) GetBit(bv byte) bool
  • func (b *Bitfield256) Mask() (ones int, value byte)
  • func (b *Bitfield256) OnesCount() (l int)
  • func (b *Bitfield256) SetBit(bv byte)
  • func (b *Bitfield256) String() string
  • func (b *Bitfield256) ToSlice() []byte
• type Set
  • func NewSet(subnets []*net.IPNet) Set
  • func (s Set) Add(subnet *net.IPNet) bool
  • func (s Set) AppendSortedTo(subnets []*net.IPNet) []*net.IPNet
  • func (s Set) Clone() Set
  • func (s Set) Delete(subnet *net.IPNet) bool
  • func (s Set) Equals(o Set) bool
  • func (s Set) String() string

Functions

func CoveringCIDRs

func CoveringCIDRs(ips []net.IP) []*net.IPNet

CoveringCIDRs returns the ip networks needed to cover the given IPs with as big mask as possible for each subnet. The analysis starts by finding all subnets using a 16-bit mask for IPv4 and a 64 bit mask for IPv6 addresses. Once the subnets are established, the mask for each one will be increased to the maximum value that still masks all IPs that it was created for.

Note: A similar method exists in Telepresence 1, but this method was not compared to it when written.

func Covers

func Covers(a, b *net.IPNet) bool

Covers answers the question if network range a contains all of network range b

func Equal

func Equal(a, b *net.IPNet) bool

Equal returns true if a and b have equal IP and masks

func Partition

func Partition(subnets []*net.IPNet, filter func(int, *net.IPNet) bool) (matched, notMatched []*net.IPNet)

Partition returns two slices, the first containing the subnets for which the filter evaluates to true, the second containing the rest.

func Unique

func Unique(subnets []*net.IPNet) []*net.IPNet

Unique will drop any subnet that is covered by another subnet from the given slice and return the resulting slice. This function will alter the given slice.

Types

type Bitfield256

type Bitfield256 [4]uint64

Bitfield256 represents 0 - 255 unique bytes.

func (*Bitfield256) ClearBit

func (b *Bitfield256) ClearBit(bv byte)

ClearBit clears the 1<<bv bit of the bitfield to 0.

func (*Bitfield256) Equals

func (b *Bitfield256) Equals(other *Bitfield256) bool

Equals returns true if this Bitfield256 equals the argument

func (*Bitfield256) GetBit

func (b *Bitfield256) GetBit(bv byte) bool

GetBit returns the value of the 1<<bv bit of the bitfield (0 is false, 1 is true).

func (*Bitfield256) Mask

func (b *Bitfield256) Mask() (ones int, value byte)

Mask returns how many bits, from left to right, that have the same value for all bytes represented by this Bitfield256 and a byte containing the value of those bits.

func (*Bitfield256) OnesCount

func (b *Bitfield256) OnesCount() (l int)

OnesCount returns the number of 1 bits in the bitfield.

func (*Bitfield256) SetBit

func (b *Bitfield256) SetBit(bv byte)

SetBit sets the 1<<bv bit of the bitfield to 1.

func (*Bitfield256) String

func (b *Bitfield256) String() string

String prints the hexadecimal representation of the bits

func (*Bitfield256) ToSlice

func (b *Bitfield256) ToSlice() []byte

ToSlice returns an ordered slice of all bytes in this Bitfield256

type Set

type Set map[setKey]struct{}

Set represents a unique unordered set of subnets.

func NewSet

func NewSet(subnets []*net.IPNet) Set

func (Set) Add

func (s Set) Add(subnet *net.IPNet) bool

Add adds a subnet to this set unless it doesn't already exist. Returns true if the subnet was added, false otherwise

func (Set) AppendSortedTo

func (s Set) AppendSortedTo(subnets []*net.IPNet) []*net.IPNet

AppendSortedTo appends the sorted subnets of this set to the given slice and returns the resulting slice

func (Set) Clone

func (s Set) Clone() Set

Clone returns a copy of this Set

func (Set) Delete

func (s Set) Delete(subnet *net.IPNet) bool

Delete deletes a subnet equal to the given subnet. Returns true if the subnet was deleted, false otherwise

func (Set) Equals

func (s Set) Equals(o Set) bool

Equals returns true if the two sets have the same content

func (Set) String

func (s Set) String() string