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