package tunnel import ( "fmt" "net" "sync" "time" InboundAdapter "github.com/Dreamacro/clash/adapters/inbound" "github.com/Dreamacro/clash/component/nat" C "github.com/Dreamacro/clash/constant" "github.com/Dreamacro/clash/dns" "github.com/Dreamacro/clash/log" channels "gopkg.in/eapache/channels.v1" ) var ( tunnel *Tunnel once sync.Once // default timeout for UDP session udpTimeout = 60 * time.Second ) // Tunnel handle relay inbound proxy and outbound proxy type Tunnel struct { tcpQueue *channels.InfiniteChannel udpQueue *channels.InfiniteChannel natTable *nat.Table rules []C.Rule proxies map[string]C.Proxy configMux sync.RWMutex // experimental features ignoreResolveFail bool // Outbound Rule mode Mode } // Add request to queue func (t *Tunnel) Add(req C.ServerAdapter) { switch req.Metadata().NetWork { case C.TCP: t.tcpQueue.In() <- req case C.UDP: t.udpQueue.In() <- req } } // Rules return all rules func (t *Tunnel) Rules() []C.Rule { return t.rules } // UpdateRules handle update rules func (t *Tunnel) UpdateRules(rules []C.Rule) { t.configMux.Lock() t.rules = rules t.configMux.Unlock() } // Proxies return all proxies func (t *Tunnel) Proxies() map[string]C.Proxy { return t.proxies } // UpdateProxies handle update proxies func (t *Tunnel) UpdateProxies(proxies map[string]C.Proxy) { t.configMux.Lock() t.proxies = proxies t.configMux.Unlock() } // UpdateExperimental handle update experimental config func (t *Tunnel) UpdateExperimental(ignoreResolveFail bool) { t.configMux.Lock() t.ignoreResolveFail = ignoreResolveFail t.configMux.Unlock() } // Mode return current mode func (t *Tunnel) Mode() Mode { return t.mode } // SetMode change the mode of tunnel func (t *Tunnel) SetMode(mode Mode) { t.mode = mode } func (t *Tunnel) process() { go func() { queue := t.udpQueue.Out() for elm := range queue { conn := elm.(C.ServerAdapter) t.handleUDPConn(conn) } }() queue := t.tcpQueue.Out() for elm := range queue { conn := elm.(C.ServerAdapter) go t.handleTCPConn(conn) } } func (t *Tunnel) resolveIP(host string) (net.IP, error) { return dns.ResolveIP(host) } func (t *Tunnel) needLookupIP(metadata *C.Metadata) bool { return dns.DefaultResolver != nil && (dns.DefaultResolver.IsMapping() || dns.DefaultResolver.IsFakeIP()) && metadata.Host == "" && metadata.DstIP != nil } func (t *Tunnel) resolveMetadata(metadata *C.Metadata) (C.Proxy, C.Rule, error) { // handle host equal IP string if ip := net.ParseIP(metadata.Host); ip != nil { metadata.DstIP = ip } // preprocess enhanced-mode metadata if t.needLookupIP(metadata) { host, exist := dns.DefaultResolver.IPToHost(metadata.DstIP) if exist { metadata.Host = host metadata.AddrType = C.AtypDomainName if dns.DefaultResolver.IsFakeIP() { metadata.DstIP = nil } } } var proxy C.Proxy var rule C.Rule switch t.mode { case Direct: proxy = t.proxies["DIRECT"] case Global: proxy = t.proxies["GLOBAL"] // Rule default: var err error proxy, rule, err = t.match(metadata) if err != nil { return nil, nil, err } } return proxy, rule, nil } func (t *Tunnel) handleUDPConn(localConn C.ServerAdapter) { metadata := localConn.Metadata() if !metadata.Valid() { log.Warnln("[Metadata] not valid: %#v", metadata) return } src := localConn.RemoteAddr().String() dst := metadata.RemoteAddress() key := src + "-" + dst pc, addr := t.natTable.Get(key) if pc != nil { t.handleUDPToRemote(localConn, pc, addr) return } lockKey := key + "-lock" wg, loaded := t.natTable.GetOrCreateLock(lockKey) go func() { if !loaded { wg.Add(1) proxy, rule, err := t.resolveMetadata(metadata) if err != nil { log.Warnln("Parse metadata failed: %s", err.Error()) t.natTable.Delete(lockKey) wg.Done() return } rawPc, nAddr, err := proxy.DialUDP(metadata) if err != nil { log.Warnln("dial %s error: %s", proxy.Name(), err.Error()) t.natTable.Delete(lockKey) wg.Done() return } addr = nAddr pc = newUDPTracker(rawPc, DefaultManager, metadata, rule) if rule != nil { log.Infoln("%s --> %v match %s using %s", metadata.SrcIP.String(), metadata.String(), rule.RuleType().String(), rawPc.Chains().String()) } else { log.Infoln("%s --> %v doesn't match any rule using DIRECT", metadata.SrcIP.String(), metadata.String()) } t.natTable.Set(key, pc, addr) t.natTable.Delete(lockKey) wg.Done() go t.handleUDPToLocal(localConn, pc, key, udpTimeout) } wg.Wait() pc, addr := t.natTable.Get(key) if pc != nil { t.handleUDPToRemote(localConn, pc, addr) } }() } func (t *Tunnel) handleTCPConn(localConn C.ServerAdapter) { defer localConn.Close() metadata := localConn.Metadata() if !metadata.Valid() { log.Warnln("[Metadata] not valid: %#v", metadata) return } proxy, rule, err := t.resolveMetadata(metadata) if err != nil { log.Warnln("Parse metadata failed: %v", err) return } remoteConn, err := proxy.Dial(metadata) if err != nil { log.Warnln("dial %s error: %s", proxy.Name(), err.Error()) return } remoteConn = newTCPTracker(remoteConn, DefaultManager, metadata, rule) defer remoteConn.Close() if rule != nil { log.Infoln("%s --> %v match %s using %s", metadata.SrcIP.String(), metadata.String(), rule.RuleType().String(), remoteConn.Chains().String()) } else { log.Infoln("%s --> %v doesn't match any rule using DIRECT", metadata.SrcIP.String(), metadata.String()) } switch adapter := localConn.(type) { case *InboundAdapter.HTTPAdapter: t.handleHTTP(adapter, remoteConn) case *InboundAdapter.SocketAdapter: t.handleSocket(adapter, remoteConn) } } func (t *Tunnel) shouldResolveIP(rule C.Rule, metadata *C.Metadata) bool { return !rule.NoResolveIP() && metadata.Host != "" && metadata.DstIP == nil } func (t *Tunnel) match(metadata *C.Metadata) (C.Proxy, C.Rule, error) { t.configMux.RLock() defer t.configMux.RUnlock() var resolved bool if node := dns.DefaultHosts.Search(metadata.Host); node != nil { ip := node.Data.(net.IP) metadata.DstIP = ip resolved = true } for _, rule := range t.rules { if !resolved && t.shouldResolveIP(rule, metadata) { ip, err := t.resolveIP(metadata.Host) if err != nil { if !t.ignoreResolveFail { return nil, nil, fmt.Errorf("[DNS] resolve %s error: %s", metadata.Host, err.Error()) } log.Debugln("[DNS] resolve %s error: %s", metadata.Host, err.Error()) } else { log.Debugln("[DNS] %s --> %s", metadata.Host, ip.String()) metadata.DstIP = ip } resolved = true } if rule.Match(metadata) { adapter, ok := t.proxies[rule.Adapter()] if !ok { continue } if metadata.NetWork == C.UDP && !adapter.SupportUDP() { log.Debugln("%v UDP is not supported", adapter.Name()) continue } return adapter, rule, nil } } return t.proxies["DIRECT"], nil, nil } func newTunnel() *Tunnel { return &Tunnel{ tcpQueue: channels.NewInfiniteChannel(), udpQueue: channels.NewInfiniteChannel(), natTable: nat.New(), proxies: make(map[string]C.Proxy), mode: Rule, } } // Instance return singleton instance of Tunnel func Instance() *Tunnel { once.Do(func() { tunnel = newTunnel() go tunnel.process() }) return tunnel }