clash/component/trie/ipcidr_trie.go
2022-03-15 02:20:19 +08:00

255 lines
4.9 KiB
Go

package trie
import (
"github.com/Dreamacro/clash/log"
"net"
)
type IPV6 bool
const (
ipv4GroupMaxValue = 0xFF
ipv6GroupMaxValue = 0xFFFF
)
type IpCidrTrie struct {
ipv4Trie *IpCidrNode
ipv6Trie *IpCidrNode
}
func NewIpCidrTrie() *IpCidrTrie {
return &IpCidrTrie{
ipv4Trie: NewIpCidrNode(false, ipv4GroupMaxValue),
ipv6Trie: NewIpCidrNode(false, ipv6GroupMaxValue),
}
}
func (trie *IpCidrTrie) AddIpCidr(ipCidr *net.IPNet) error {
subIpCidr, subCidr, isIpv4, err := ipCidrToSubIpCidr(ipCidr)
if err != nil {
return err
}
for _, sub := range subIpCidr {
addIpCidr(trie, isIpv4, sub, subCidr/8)
}
return nil
}
func (trie *IpCidrTrie) AddIpCidrForString(ipCidr string) error {
_, ipNet, err := net.ParseCIDR(ipCidr)
if err != nil {
return err
}
return trie.AddIpCidr(ipNet)
}
func (trie *IpCidrTrie) IsContain(ip net.IP) bool {
ip, isIpv4 := checkAndConverterIp(ip)
if ip == nil {
return false
}
var groupValues []uint32
var ipCidrNode *IpCidrNode
if isIpv4 {
ipCidrNode = trie.ipv4Trie
for _, group := range ip {
groupValues = append(groupValues, uint32(group))
}
} else {
ipCidrNode = trie.ipv6Trie
for i := 0; i < len(ip); i += 2 {
groupValues = append(groupValues, getIpv6GroupValue(ip[i], ip[i+1]))
}
}
return search(ipCidrNode, groupValues) != nil
}
func (trie *IpCidrTrie) IsContainForString(ipString string) bool {
return trie.IsContain(net.ParseIP(ipString))
}
func ipCidrToSubIpCidr(ipNet *net.IPNet) ([]net.IP, int, bool, error) {
maskSize, _ := ipNet.Mask.Size()
var (
ipList []net.IP
newMaskSize int
isIpv4 bool
err error
)
ip, isIpv4 := checkAndConverterIp(ipNet.IP)
ipList, newMaskSize, err = subIpCidr(ip, maskSize, isIpv4)
return ipList, newMaskSize, isIpv4, err
}
func subIpCidr(ip net.IP, maskSize int, isIpv4 bool) ([]net.IP, int, error) {
var subIpCidrList []net.IP
groupSize := 8
if !isIpv4 {
groupSize = 16
}
if maskSize%groupSize == 0 {
return append(subIpCidrList, ip), maskSize, nil
}
lastByteMaskSize := maskSize % 8
lastByteMaskIndex := maskSize / 8
subIpCidrNum := 0xFF >> lastByteMaskSize
for i := 0; i <= subIpCidrNum; i++ {
subIpCidr := make([]byte, len(ip))
copy(subIpCidr, ip)
subIpCidr[lastByteMaskIndex] += byte(i)
subIpCidrList = append(subIpCidrList, subIpCidr)
}
newMaskSize := (lastByteMaskIndex + 1) * 8
if !isIpv4 {
newMaskSize = (lastByteMaskIndex/2 + 1) * 16
}
return subIpCidrList, newMaskSize, nil
}
func addIpCidr(trie *IpCidrTrie, isIpv4 bool, ip net.IP, groupSize int) {
if isIpv4 {
addIpv4Cidr(trie, ip, groupSize)
} else {
addIpv6Cidr(trie, ip, groupSize)
}
}
func addIpv4Cidr(trie *IpCidrTrie, ip net.IP, groupSize int) {
preNode := trie.ipv4Trie
node := preNode.getChild(uint32(ip[0]))
if node == nil {
err := preNode.addChild(uint32(ip[0]))
if err != nil {
return
}
node = preNode.getChild(uint32(ip[0]))
}
for i := 1; i < groupSize; i++ {
if node.Mark {
return
}
groupValue := uint32(ip[i])
if !node.hasChild(groupValue) {
err := node.addChild(groupValue)
if err != nil {
log.Errorln(err.Error())
}
}
preNode = node
node = node.getChild(groupValue)
if node == nil {
err := preNode.addChild(uint32(ip[i-1]))
if err != nil {
return
}
node = preNode.getChild(uint32(ip[i-1]))
}
}
node.Mark = true
cleanChild(node)
}
func addIpv6Cidr(trie *IpCidrTrie, ip net.IP, groupSize int) {
preNode := trie.ipv6Trie
node := preNode.getChild(getIpv6GroupValue(ip[0], ip[1]))
if node == nil {
err := preNode.addChild(getIpv6GroupValue(ip[0], ip[1]))
if err != nil {
return
}
node = preNode.getChild(getIpv6GroupValue(ip[0], ip[1]))
}
for i := 2; i < groupSize; i += 2 {
if node.Mark {
return
}
groupValue := getIpv6GroupValue(ip[i], ip[i+1])
if !node.hasChild(groupValue) {
err := node.addChild(groupValue)
if err != nil {
log.Errorln(err.Error())
}
}
preNode = node
node = node.getChild(groupValue)
if node == nil {
err := preNode.addChild(getIpv6GroupValue(ip[i-2], ip[i-1]))
if err != nil {
return
}
node = preNode.getChild(getIpv6GroupValue(ip[i-2], ip[i-1]))
}
}
node.Mark = true
cleanChild(node)
}
func getIpv6GroupValue(high, low byte) uint32 {
return (uint32(high) << 8) | uint32(low)
}
func cleanChild(node *IpCidrNode) {
for i := uint32(0); i < uint32(len(node.child)); i++ {
delete(node.child, i)
}
}
func search(root *IpCidrNode, groupValues []uint32) *IpCidrNode {
node := root.getChild(groupValues[0])
if node == nil || node.Mark {
return node
}
for _, value := range groupValues[1:] {
if !node.hasChild(value) {
return nil
}
node = node.getChild(value)
if node == nil || node.Mark {
return node
}
}
return nil
}
// return net.IP To4 or To16 and is ipv4
func checkAndConverterIp(ip net.IP) (net.IP, bool) {
ipResult := ip.To4()
if ipResult == nil {
ipResult = ip.To16()
if ipResult == nil {
return nil, false
}
return ipResult, false
}
return ipResult, true
}