141 lines
2.6 KiB
Go
141 lines
2.6 KiB
Go
package fakeip
|
|
|
|
import (
|
|
"errors"
|
|
"net"
|
|
"sync"
|
|
|
|
"github.com/Dreamacro/clash/common/cache"
|
|
trie "github.com/Dreamacro/clash/component/domain-trie"
|
|
)
|
|
|
|
// Pool is a implementation about fake ip generator without storage
|
|
type Pool struct {
|
|
max uint32
|
|
min uint32
|
|
gateway uint32
|
|
offset uint32
|
|
mux sync.Mutex
|
|
host *trie.Trie
|
|
cache *cache.LruCache
|
|
}
|
|
|
|
// Lookup return a fake ip with host
|
|
func (p *Pool) Lookup(host string) net.IP {
|
|
p.mux.Lock()
|
|
defer p.mux.Unlock()
|
|
if elm, exist := p.cache.Get(host); exist {
|
|
ip := elm.(net.IP)
|
|
|
|
// ensure ip --> host on head of linked list
|
|
n := ipToUint(ip.To4())
|
|
offset := n - p.min + 1
|
|
p.cache.Get(offset)
|
|
return ip
|
|
}
|
|
|
|
ip := p.get(host)
|
|
p.cache.Set(host, ip)
|
|
return ip
|
|
}
|
|
|
|
// LookBack return host with the fake ip
|
|
func (p *Pool) LookBack(ip net.IP) (string, bool) {
|
|
p.mux.Lock()
|
|
defer p.mux.Unlock()
|
|
|
|
if ip = ip.To4(); ip == nil {
|
|
return "", false
|
|
}
|
|
|
|
n := ipToUint(ip.To4())
|
|
offset := n - p.min + 1
|
|
|
|
if elm, exist := p.cache.Get(offset); exist {
|
|
host := elm.(string)
|
|
|
|
// ensure host --> ip on head of linked list
|
|
p.cache.Get(host)
|
|
return host, true
|
|
}
|
|
|
|
return "", false
|
|
}
|
|
|
|
// LookupHost return if domain in host
|
|
func (p *Pool) LookupHost(domain string) bool {
|
|
if p.host == nil {
|
|
return false
|
|
}
|
|
return p.host.Search(domain) != nil
|
|
}
|
|
|
|
// Exist returns if given ip exists in fake-ip pool
|
|
func (p *Pool) Exist(ip net.IP) bool {
|
|
p.mux.Lock()
|
|
defer p.mux.Unlock()
|
|
|
|
if ip = ip.To4(); ip == nil {
|
|
return false
|
|
}
|
|
|
|
n := ipToUint(ip.To4())
|
|
offset := n - p.min + 1
|
|
return p.cache.Exist(offset)
|
|
}
|
|
|
|
// Gateway return gateway ip
|
|
func (p *Pool) Gateway() net.IP {
|
|
return uintToIP(p.gateway)
|
|
}
|
|
|
|
func (p *Pool) get(host string) net.IP {
|
|
current := p.offset
|
|
for {
|
|
p.offset = (p.offset + 1) % (p.max - p.min)
|
|
// Avoid infinite loops
|
|
if p.offset == current {
|
|
break
|
|
}
|
|
|
|
if !p.cache.Exist(p.offset) {
|
|
break
|
|
}
|
|
}
|
|
ip := uintToIP(p.min + p.offset - 1)
|
|
p.cache.Set(p.offset, host)
|
|
return ip
|
|
}
|
|
|
|
func ipToUint(ip net.IP) uint32 {
|
|
v := uint32(ip[0]) << 24
|
|
v += uint32(ip[1]) << 16
|
|
v += uint32(ip[2]) << 8
|
|
v += uint32(ip[3])
|
|
return v
|
|
}
|
|
|
|
func uintToIP(v uint32) net.IP {
|
|
return net.IPv4(byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
|
|
}
|
|
|
|
// New return Pool instance
|
|
func New(ipnet *net.IPNet, size int, host *trie.Trie) (*Pool, error) {
|
|
min := ipToUint(ipnet.IP) + 2
|
|
|
|
ones, bits := ipnet.Mask.Size()
|
|
total := 1<<uint(bits-ones) - 2
|
|
|
|
if total <= 0 {
|
|
return nil, errors.New("ipnet don't have valid ip")
|
|
}
|
|
|
|
max := min + uint32(total) - 1
|
|
return &Pool{
|
|
min: min,
|
|
max: max,
|
|
gateway: min - 1,
|
|
host: host,
|
|
cache: cache.NewLRUCache(cache.WithSize(size * 2)),
|
|
}, nil
|
|
}
|