mirror of
https://github.com/MetaCubeX/mihomo.git
synced 2024-08-21 09:54:07 +00:00
341 lines
7.1 KiB
Go
341 lines
7.1 KiB
Go
package dns
|
|
|
|
import (
|
|
"context"
|
|
"crypto/tls"
|
|
"errors"
|
|
"fmt"
|
|
"math/rand"
|
|
"net"
|
|
"strings"
|
|
"time"
|
|
|
|
"github.com/Dreamacro/clash/common/cache"
|
|
"github.com/Dreamacro/clash/common/picker"
|
|
"github.com/Dreamacro/clash/component/fakeip"
|
|
"github.com/Dreamacro/clash/component/resolver"
|
|
|
|
D "github.com/miekg/dns"
|
|
"golang.org/x/sync/singleflight"
|
|
)
|
|
|
|
var (
|
|
globalSessionCache = tls.NewLRUClientSessionCache(64)
|
|
)
|
|
|
|
type dnsClient interface {
|
|
Exchange(m *D.Msg) (msg *D.Msg, err error)
|
|
ExchangeContext(ctx context.Context, m *D.Msg) (msg *D.Msg, err error)
|
|
}
|
|
|
|
type result struct {
|
|
Msg *D.Msg
|
|
Error error
|
|
}
|
|
|
|
type Resolver struct {
|
|
ipv6 bool
|
|
mapping bool
|
|
fakeip bool
|
|
pool *fakeip.Pool
|
|
main []dnsClient
|
|
fallback []dnsClient
|
|
fallbackFilters []fallbackFilter
|
|
group singleflight.Group
|
|
lruCache *cache.LruCache
|
|
}
|
|
|
|
// ResolveIP request with TypeA and TypeAAAA, priority return TypeA
|
|
func (r *Resolver) ResolveIP(host string) (ip net.IP, err error) {
|
|
ch := make(chan net.IP, 1)
|
|
go func() {
|
|
defer close(ch)
|
|
ip, err := r.resolveIP(host, D.TypeAAAA)
|
|
if err != nil {
|
|
return
|
|
}
|
|
ch <- ip
|
|
}()
|
|
|
|
ip, err = r.resolveIP(host, D.TypeA)
|
|
if err == nil {
|
|
return
|
|
}
|
|
|
|
ip, open := <-ch
|
|
if !open {
|
|
return nil, resolver.ErrIPNotFound
|
|
}
|
|
|
|
return ip, nil
|
|
}
|
|
|
|
// ResolveIPv4 request with TypeA
|
|
func (r *Resolver) ResolveIPv4(host string) (ip net.IP, err error) {
|
|
return r.resolveIP(host, D.TypeA)
|
|
}
|
|
|
|
// ResolveIPv6 request with TypeAAAA
|
|
func (r *Resolver) ResolveIPv6(host string) (ip net.IP, err error) {
|
|
return r.resolveIP(host, D.TypeAAAA)
|
|
}
|
|
|
|
func (r *Resolver) shouldFallback(ip net.IP) bool {
|
|
for _, filter := range r.fallbackFilters {
|
|
if filter.Match(ip) {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
// Exchange a batch of dns request, and it use cache
|
|
func (r *Resolver) Exchange(m *D.Msg) (msg *D.Msg, err error) {
|
|
if len(m.Question) == 0 {
|
|
return nil, errors.New("should have one question at least")
|
|
}
|
|
|
|
q := m.Question[0]
|
|
cache, expireTime, hit := r.lruCache.GetWithExpire(q.String())
|
|
if hit {
|
|
now := time.Now()
|
|
msg = cache.(*D.Msg).Copy()
|
|
if expireTime.Before(now) {
|
|
setMsgTTL(msg, uint32(1)) // Continue fetch
|
|
go r.exchangeWithoutCache(m)
|
|
} else {
|
|
setMsgTTL(msg, uint32(expireTime.Sub(time.Now()).Seconds()))
|
|
}
|
|
return
|
|
}
|
|
return r.exchangeWithoutCache(m)
|
|
}
|
|
|
|
// ExchangeWithoutCache a batch of dns request, and it do NOT GET from cache
|
|
func (r *Resolver) exchangeWithoutCache(m *D.Msg) (msg *D.Msg, err error) {
|
|
q := m.Question[0]
|
|
|
|
defer func() {
|
|
if msg == nil {
|
|
return
|
|
}
|
|
|
|
putMsgToCache(r.lruCache, q.String(), msg)
|
|
if r.mapping || r.fakeip {
|
|
ips := r.msgToIP(msg)
|
|
for _, ip := range ips {
|
|
putMsgToCache(r.lruCache, ip.String(), msg)
|
|
}
|
|
}
|
|
}()
|
|
|
|
ret, err, shared := r.group.Do(q.String(), func() (interface{}, error) {
|
|
isIPReq := isIPRequest(q)
|
|
if isIPReq {
|
|
return r.fallbackExchange(m)
|
|
}
|
|
|
|
return r.batchExchange(r.main, m)
|
|
})
|
|
|
|
if err == nil {
|
|
msg = ret.(*D.Msg)
|
|
if shared {
|
|
msg = msg.Copy()
|
|
}
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
// IPToHost return fake-ip or redir-host mapping host
|
|
func (r *Resolver) IPToHost(ip net.IP) (string, bool) {
|
|
if r.fakeip {
|
|
record, existed := r.pool.LookBack(ip)
|
|
if existed {
|
|
return record, true
|
|
}
|
|
}
|
|
|
|
cache, _ := r.lruCache.Get(ip.String())
|
|
if cache == nil {
|
|
return "", false
|
|
}
|
|
fqdn := cache.(*D.Msg).Question[0].Name
|
|
return strings.TrimRight(fqdn, "."), true
|
|
}
|
|
|
|
func (r *Resolver) IsMapping() bool {
|
|
return r.mapping
|
|
}
|
|
|
|
// FakeIPEnabled returns if fake-ip is enabled
|
|
func (r *Resolver) FakeIPEnabled() bool {
|
|
return r.fakeip
|
|
}
|
|
|
|
// IsFakeIP determine if given ip is a fake-ip
|
|
func (r *Resolver) IsFakeIP(ip net.IP) bool {
|
|
if r.FakeIPEnabled() {
|
|
return r.pool.Exist(ip)
|
|
}
|
|
return false
|
|
}
|
|
|
|
func (r *Resolver) batchExchange(clients []dnsClient, m *D.Msg) (msg *D.Msg, err error) {
|
|
fast, ctx := picker.WithTimeout(context.Background(), time.Second*5)
|
|
for _, client := range clients {
|
|
r := client
|
|
fast.Go(func() (interface{}, error) {
|
|
m, err := r.ExchangeContext(ctx, m)
|
|
if err != nil {
|
|
return nil, err
|
|
} else if m.Rcode == D.RcodeServerFailure || m.Rcode == D.RcodeRefused {
|
|
return nil, errors.New("server failure")
|
|
}
|
|
return m, nil
|
|
})
|
|
}
|
|
|
|
elm := fast.Wait()
|
|
if elm == nil {
|
|
err := errors.New("All DNS requests failed")
|
|
if fErr := fast.Error(); fErr != nil {
|
|
err = fmt.Errorf("%w, first error: %s", err, fErr.Error())
|
|
}
|
|
return nil, err
|
|
}
|
|
|
|
msg = elm.(*D.Msg)
|
|
return
|
|
}
|
|
|
|
func (r *Resolver) fallbackExchange(m *D.Msg) (msg *D.Msg, err error) {
|
|
msgCh := r.asyncExchange(r.main, m)
|
|
if r.fallback == nil {
|
|
res := <-msgCh
|
|
msg, err = res.Msg, res.Error
|
|
return
|
|
}
|
|
fallbackMsg := r.asyncExchange(r.fallback, m)
|
|
res := <-msgCh
|
|
if res.Error == nil {
|
|
if ips := r.msgToIP(res.Msg); len(ips) != 0 {
|
|
if !r.shouldFallback(ips[0]) {
|
|
msg = res.Msg
|
|
err = res.Error
|
|
return msg, err
|
|
}
|
|
}
|
|
}
|
|
|
|
res = <-fallbackMsg
|
|
msg, err = res.Msg, res.Error
|
|
return
|
|
}
|
|
|
|
func (r *Resolver) resolveIP(host string, dnsType uint16) (ip net.IP, err error) {
|
|
ip = net.ParseIP(host)
|
|
if ip != nil {
|
|
isIPv4 := ip.To4() != nil
|
|
if dnsType == D.TypeAAAA && !isIPv4 {
|
|
return ip, nil
|
|
} else if dnsType == D.TypeA && isIPv4 {
|
|
return ip, nil
|
|
} else {
|
|
return nil, resolver.ErrIPVersion
|
|
}
|
|
}
|
|
|
|
query := &D.Msg{}
|
|
query.SetQuestion(D.Fqdn(host), dnsType)
|
|
|
|
msg, err := r.Exchange(query)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
ips := r.msgToIP(msg)
|
|
ipLength := len(ips)
|
|
if ipLength == 0 {
|
|
return nil, resolver.ErrIPNotFound
|
|
}
|
|
|
|
ip = ips[rand.Intn(ipLength)]
|
|
return
|
|
}
|
|
|
|
func (r *Resolver) msgToIP(msg *D.Msg) []net.IP {
|
|
ips := []net.IP{}
|
|
|
|
for _, answer := range msg.Answer {
|
|
switch ans := answer.(type) {
|
|
case *D.AAAA:
|
|
ips = append(ips, ans.AAAA)
|
|
case *D.A:
|
|
ips = append(ips, ans.A)
|
|
}
|
|
}
|
|
|
|
return ips
|
|
}
|
|
|
|
func (r *Resolver) asyncExchange(client []dnsClient, msg *D.Msg) <-chan *result {
|
|
ch := make(chan *result, 1)
|
|
go func() {
|
|
res, err := r.batchExchange(client, msg)
|
|
ch <- &result{Msg: res, Error: err}
|
|
}()
|
|
return ch
|
|
}
|
|
|
|
type NameServer struct {
|
|
Net string
|
|
Addr string
|
|
}
|
|
|
|
type FallbackFilter struct {
|
|
GeoIP bool
|
|
IPCIDR []*net.IPNet
|
|
}
|
|
|
|
type Config struct {
|
|
Main, Fallback []NameServer
|
|
Default []NameServer
|
|
IPv6 bool
|
|
EnhancedMode EnhancedMode
|
|
FallbackFilter FallbackFilter
|
|
Pool *fakeip.Pool
|
|
}
|
|
|
|
func New(config Config) *Resolver {
|
|
defaultResolver := &Resolver{
|
|
main: transform(config.Default, nil),
|
|
lruCache: cache.NewLRUCache(cache.WithSize(4096), cache.WithStale(true)),
|
|
}
|
|
|
|
r := &Resolver{
|
|
ipv6: config.IPv6,
|
|
main: transform(config.Main, defaultResolver),
|
|
lruCache: cache.NewLRUCache(cache.WithSize(4096), cache.WithStale(true)),
|
|
mapping: config.EnhancedMode == MAPPING,
|
|
fakeip: config.EnhancedMode == FAKEIP,
|
|
pool: config.Pool,
|
|
}
|
|
|
|
if len(config.Fallback) != 0 {
|
|
r.fallback = transform(config.Fallback, defaultResolver)
|
|
}
|
|
|
|
fallbackFilters := []fallbackFilter{}
|
|
if config.FallbackFilter.GeoIP {
|
|
fallbackFilters = append(fallbackFilters, &geoipFilter{})
|
|
}
|
|
for _, ipnet := range config.FallbackFilter.IPCIDR {
|
|
fallbackFilters = append(fallbackFilters, &ipnetFilter{ipnet: ipnet})
|
|
}
|
|
r.fallbackFilters = fallbackFilters
|
|
|
|
return r
|
|
}
|