range2cidr

README

range2cidr

Aggregate() merges a list of IP ranges into a minimal set of covering ranges.

Deaggregate() breaks a single IP range into a list of covering network prefixes.

A number of address helper functions are exposed for convenience.

This library usually operates on addresses as [16]byte values, as returned by netip.Addr.As16().

To convert a netip.Addr into [16]byte:

addr.As16()

To unmap an address back into IPv4 format:

if addr.Is4In6() {
	return addr.Unmap()
}

The last step is crucial if you want results in v4 format instead of 4in6.

Documentation

Overview

Aggregate() merges a list of IP ranges into a minimal set of covering ranges.

Deaggregate() breaks a single IP range into a list of covering network prefixes.

A number of address helper functions are exposed for convenience.

This library usually operates on addresses as [16]byte values, as returned by netip.Addr.As16().

To convert a netip.Addr into [16]byte:

addr.As16()

To unmap an address back into IPv4 format:

if addr.Is4In6() {
	return addr.Unmap()
}

The last step is crucial if you want results in v4 format instead of 4in6.

Index

• func Add(a, b *[16]byte) (ret [16]byte, carry int)
• func Cmp(a, b *[16]byte) int
• func GetBit(a *[16]byte, n uint) bool
• func SetBit(a *[16]byte, n uint, bSet bool)
• func ToBig(addr netip.Addr) *big.Int
• func Uint32ToV4(n32 uint32) netip.Addr
• func V4ToUint32(ipaddr netip.Addr) (uint32, bool)
• type Range
  • func Aggregate(sR []Range) []Range
  • func RangeFromAddrs(first, last netip.Addr) Range
  • func RangeFromPrefix(pfx netip.Prefix) Range
  • func (v Range) Deaggregate() []netip.Prefix
  • func (v *Range) Normalize()

Functions

func Add

func Add(a, b *[16]byte) (ret [16]byte, carry int)

returns sum of a and b, and carry bit.

func Cmp

func Cmp(a, b *[16]byte) int

compare two IPs. the result will be 0 if (a == b), -1 if (a < b), and +1 if (a > b).

func GetBit

func GetBit(a *[16]byte, n uint) bool

get n-th bit in a. returns true if set, false if not.

func SetBit

func SetBit(a *[16]byte, n uint, bSet bool)

set/clear n-th bit in a.

func ToBig

func ToBig(addr netip.Addr) *big.Int

func Uint32ToV4

func Uint32ToV4(n32 uint32) netip.Addr

func V4ToUint32

func V4ToUint32(ipaddr netip.Addr) (uint32, bool)

Types

type Range

type Range struct {
	A, Z [16]byte
}

func Aggregate

func Aggregate(sR []Range) []Range

aggregate (merge) adjacent and contained ranges.

NOTE: mutates sR.

func RangeFromAddrs

func RangeFromAddrs(first, last netip.Addr) Range

convert first, last addresses to a Range struct

func RangeFromPrefix

func RangeFromPrefix(pfx netip.Prefix) Range

convert network prefix to a Range struct

func (Range) Deaggregate

func (v Range) Deaggregate() []netip.Prefix

de-aggregate a range of IP addresses into a list of covering network prefixes.

func (*Range) Normalize

func (v *Range) Normalize()

sort range to ensure that A <= Z.