mirror of https://github.com/v2ray/v2ray-core
84 lines
1.4 KiB
Go
84 lines
1.4 KiB
Go
package net
|
|
|
|
import (
|
|
"math/bits"
|
|
"net"
|
|
)
|
|
|
|
type IPNetTable struct {
|
|
cache map[uint32]byte
|
|
}
|
|
|
|
func NewIPNetTable() *IPNetTable {
|
|
return &IPNetTable{
|
|
cache: make(map[uint32]byte, 1024),
|
|
}
|
|
}
|
|
|
|
func ipToUint32(ip IP) uint32 {
|
|
value := uint32(0)
|
|
for _, b := range []byte(ip) {
|
|
value <<= 8
|
|
value += uint32(b)
|
|
}
|
|
return value
|
|
}
|
|
|
|
func ipMaskToByte(mask net.IPMask) byte {
|
|
value := byte(0)
|
|
for _, b := range []byte(mask) {
|
|
value += byte(bits.OnesCount8(b))
|
|
}
|
|
return value
|
|
}
|
|
|
|
func (n *IPNetTable) Add(ipNet *net.IPNet) {
|
|
ipv4 := ipNet.IP.To4()
|
|
if ipv4 == nil {
|
|
// For now, we don't support IPv6
|
|
return
|
|
}
|
|
mask := ipMaskToByte(ipNet.Mask)
|
|
n.AddIP(ipv4, mask)
|
|
}
|
|
|
|
func (n *IPNetTable) AddIP(ip []byte, mask byte) {
|
|
k := ipToUint32(ip)
|
|
k = (k >> (32 - mask)) << (32 - mask) // normalize ip
|
|
existing, found := n.cache[k]
|
|
if !found || existing > mask {
|
|
n.cache[k] = mask
|
|
}
|
|
}
|
|
|
|
func (n *IPNetTable) Contains(ip net.IP) bool {
|
|
ipv4 := ip.To4()
|
|
if ipv4 == nil {
|
|
return false
|
|
}
|
|
originalValue := ipToUint32(ipv4)
|
|
|
|
if entry, found := n.cache[originalValue]; found {
|
|
if entry == 32 {
|
|
return true
|
|
}
|
|
}
|
|
|
|
mask := uint32(0)
|
|
for maskbit := byte(1); maskbit <= 32; maskbit++ {
|
|
mask += 1 << uint32(32-maskbit)
|
|
|
|
maskedValue := originalValue & mask
|
|
if entry, found := n.cache[maskedValue]; found {
|
|
if entry == maskbit {
|
|
return true
|
|
}
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
func (n *IPNetTable) IsEmpty() bool {
|
|
return len(n.cache) == 0
|
|
}
|