clash/tunnel/tunnel.go

432 lines
10 KiB
Go

package tunnel
import (
"context"
"fmt"
"net"
"net/netip"
"runtime"
"sync"
"time"
"github.com/Dreamacro/clash/adapter/inbound"
"github.com/Dreamacro/clash/component/nat"
P "github.com/Dreamacro/clash/component/process"
"github.com/Dreamacro/clash/component/resolver"
C "github.com/Dreamacro/clash/constant"
"github.com/Dreamacro/clash/constant/provider"
icontext "github.com/Dreamacro/clash/context"
"github.com/Dreamacro/clash/log"
"github.com/Dreamacro/clash/tunnel/statistic"
"go.uber.org/atomic"
)
var (
tcpQueue = make(chan C.ConnContext, 200)
udpQueue = make(chan *inbound.PacketAdapter, 200)
natTable = nat.New()
rules []C.Rule
proxies = make(map[string]C.Proxy)
providers map[string]provider.ProxyProvider
configMux sync.RWMutex
// Outbound Rule
mode = Rule
// default timeout for UDP session
udpTimeout = 60 * time.Second
// experimental feature
UDPFallbackMatch = atomic.NewBool(false)
)
func init() {
go process()
}
// TCPIn return fan-in queue
func TCPIn() chan<- C.ConnContext {
return tcpQueue
}
// UDPIn return fan-in udp queue
func UDPIn() chan<- *inbound.PacketAdapter {
return udpQueue
}
// Rules return all rules
func Rules() []C.Rule {
return rules
}
// UpdateRules handle update rules
func UpdateRules(newRules []C.Rule) {
configMux.Lock()
rules = newRules
configMux.Unlock()
}
// Proxies return all proxies
func Proxies() map[string]C.Proxy {
return proxies
}
// Providers return all compatible providers
func Providers() map[string]provider.ProxyProvider {
return providers
}
// UpdateProxies handle update proxies
func UpdateProxies(newProxies map[string]C.Proxy, newProviders map[string]provider.ProxyProvider) {
configMux.Lock()
proxies = newProxies
providers = newProviders
configMux.Unlock()
}
// Mode return current mode
func Mode() TunnelMode {
return mode
}
// SetMode change the mode of tunnel
func SetMode(m TunnelMode) {
mode = m
}
// processUDP starts a loop to handle udp packet
func processUDP() {
queue := udpQueue
for conn := range queue {
handleUDPConn(conn)
}
}
func process() {
numUDPWorkers := 4
if num := runtime.GOMAXPROCS(0); num > numUDPWorkers {
numUDPWorkers = num
}
for i := 0; i < numUDPWorkers; i++ {
go processUDP()
}
queue := tcpQueue
for conn := range queue {
go handleTCPConn(conn)
}
}
func needLookupIP(metadata *C.Metadata) bool {
return resolver.MappingEnabled() && metadata.Host == "" && metadata.DstIP != nil
}
func preHandleMetadata(metadata *C.Metadata) error {
// handle IP string on host
if ip := net.ParseIP(metadata.Host); ip != nil {
metadata.DstIP = ip
metadata.Host = ""
}
// preprocess enhanced-mode metadata
if needLookupIP(metadata) {
host, exist := resolver.FindHostByIP(metadata.DstIP)
if exist {
metadata.Host = host
metadata.DNSMode = C.DNSMapping
if resolver.FakeIPEnabled() {
metadata.DstIP = nil
metadata.DNSMode = C.DNSFakeIP
} else if node := resolver.DefaultHosts.Search(host); node != nil {
// redir-host should lookup the hosts
metadata.DstIP = node.Data.(net.IP)
}
} else if resolver.IsFakeIP(metadata.DstIP) {
return fmt.Errorf("fake DNS record %s missing", metadata.DstIP)
}
}
return nil
}
func resolveMetadata(ctx C.PlainContext, metadata *C.Metadata) (proxy C.Proxy, rule C.Rule, err error) {
if metadata.SpecialProxy != "" {
var exist bool
proxy, exist = proxies[metadata.SpecialProxy]
if !exist {
err = fmt.Errorf("proxy %s not found", metadata.SpecialProxy)
}
return
}
switch mode {
case Direct:
proxy = proxies["DIRECT"]
case Global:
proxy = proxies["GLOBAL"]
// Rule
default:
proxy, rule, err = match(metadata)
}
return
}
func handleUDPConn(packet *inbound.PacketAdapter) {
metadata := packet.Metadata()
if !metadata.Valid() {
packet.Drop()
log.Warnln("[Metadata] not valid: %#v", metadata)
return
}
// make a fAddr if request ip is fakeip
var fAddr netip.Addr
if resolver.IsExistFakeIP(metadata.DstIP) {
fAddr, _ = netip.AddrFromSlice(metadata.DstIP)
fAddr = fAddr.Unmap()
}
if err := preHandleMetadata(metadata); err != nil {
packet.Drop()
log.Debugln("[Metadata PreHandle] error: %s", err)
return
}
// local resolve UDP dns
if !metadata.Resolved() {
ips, err := resolver.LookupIP(context.Background(), metadata.Host)
if err != nil {
packet.Drop()
return
} else if len(ips) == 0 {
packet.Drop()
return
}
metadata.DstIP = ips[0]
}
key := packet.LocalAddr().String()
handle := func() bool {
pc := natTable.Get(key)
if pc != nil {
handleUDPToRemote(packet, pc, metadata)
return true
}
return false
}
if handle() {
packet.Drop()
return
}
lockKey := key + "-lock"
cond, loaded := natTable.GetOrCreateLock(lockKey)
go func() {
defer packet.Drop()
if loaded {
cond.L.Lock()
cond.Wait()
handle()
cond.L.Unlock()
return
}
defer func() {
natTable.Delete(lockKey)
cond.Broadcast()
}()
pCtx := icontext.NewPacketConnContext(metadata)
proxy, rule, err := resolveMetadata(pCtx, metadata)
if err != nil {
log.Warnln("[UDP] Parse metadata failed: %s", err.Error())
return
}
ctx, cancel := context.WithTimeout(context.Background(), C.DefaultUDPTimeout)
defer cancel()
rawPc, err := proxy.ListenPacketContext(ctx, metadata.Pure())
if err != nil {
if rule == nil {
log.Warnln(
"[UDP] dial %s %s --> %s error: %s",
proxy.Name(),
metadata.SourceAddress(),
metadata.RemoteAddress(),
err.Error(),
)
} else {
log.Warnln("[UDP] dial %s (match %s/%s) %s --> %s error: %s", proxy.Name(), rule.RuleType().String(), rule.Payload(), metadata.SourceAddress(), metadata.RemoteAddress(), err.Error())
}
return
}
pCtx.InjectPacketConn(rawPc)
pc := statistic.NewUDPTracker(rawPc, statistic.DefaultManager, metadata, rule)
switch true {
case metadata.SpecialProxy != "":
log.Infoln("[UDP] %s --> %s using %s", metadata.SourceAddress(), metadata.RemoteAddress(), metadata.SpecialProxy)
case rule != nil:
log.Infoln(
"[UDP] %s --> %s match %s(%s) using %s",
metadata.SourceAddress(),
metadata.RemoteAddress(),
rule.RuleType().String(),
rule.Payload(),
rawPc.Chains().String(),
)
case mode == Global:
log.Infoln("[UDP] %s --> %s using GLOBAL", metadata.SourceAddress(), metadata.RemoteAddress())
case mode == Direct:
log.Infoln("[UDP] %s --> %s using DIRECT", metadata.SourceAddress(), metadata.RemoteAddress())
default:
log.Infoln(
"[UDP] %s --> %s doesn't match any rule using DIRECT",
metadata.SourceAddress(),
metadata.RemoteAddress(),
)
}
oAddr, _ := netip.AddrFromSlice(metadata.DstIP)
oAddr = oAddr.Unmap()
go handleUDPToLocal(packet.UDPPacket, pc, key, oAddr, fAddr)
natTable.Set(key, pc)
handle()
}()
}
func handleTCPConn(connCtx C.ConnContext) {
defer connCtx.Conn().Close()
metadata := connCtx.Metadata()
if !metadata.Valid() {
log.Warnln("[Metadata] not valid: %#v", metadata)
return
}
if err := preHandleMetadata(metadata); err != nil {
log.Debugln("[Metadata PreHandle] error: %s", err)
return
}
proxy, rule, err := resolveMetadata(connCtx, metadata)
if err != nil {
log.Warnln("[Metadata] parse failed: %s", err.Error())
return
}
ctx, cancel := context.WithTimeout(context.Background(), C.DefaultTCPTimeout)
defer cancel()
remoteConn, err := proxy.DialContext(ctx, metadata.Pure())
if err != nil {
if rule == nil {
log.Warnln(
"[TCP] dial %s %s --> %s error: %s",
proxy.Name(),
metadata.SourceAddress(),
metadata.RemoteAddress(),
err.Error(),
)
} else {
log.Warnln("[TCP] dial %s (match %s/%s) %s --> %s error: %s", proxy.Name(), rule.RuleType().String(), rule.Payload(), metadata.SourceAddress(), metadata.RemoteAddress(), err.Error())
}
return
}
remoteConn = statistic.NewTCPTracker(remoteConn, statistic.DefaultManager, metadata, rule)
defer remoteConn.Close()
switch true {
case metadata.SpecialProxy != "":
log.Infoln("[TCP] %s --> %s using %s", metadata.SourceAddress(), metadata.RemoteAddress(), metadata.SpecialProxy)
case rule != nil:
log.Infoln(
"[TCP] %s --> %s match %s(%s) using %s",
metadata.SourceAddress(),
metadata.RemoteAddress(),
rule.RuleType().String(),
rule.Payload(),
remoteConn.Chains().String(),
)
case mode == Global:
log.Infoln("[TCP] %s --> %s using GLOBAL", metadata.SourceAddress(), metadata.RemoteAddress())
case mode == Direct:
log.Infoln("[TCP] %s --> %s using DIRECT", metadata.SourceAddress(), metadata.RemoteAddress())
default:
log.Infoln(
"[TCP] %s --> %s doesn't match any rule using DIRECT",
metadata.SourceAddress(),
metadata.RemoteAddress(),
)
}
handleSocket(connCtx, remoteConn)
}
func shouldResolveIP(rule C.Rule, metadata *C.Metadata) bool {
return rule.ShouldResolveIP() && metadata.Host != "" && metadata.DstIP == nil
}
func match(metadata *C.Metadata) (C.Proxy, C.Rule, error) {
configMux.RLock()
defer configMux.RUnlock()
var resolved bool
var processFound bool
if node := resolver.DefaultHosts.Search(metadata.Host); node != nil {
ip := node.Data.(net.IP)
metadata.DstIP = ip
resolved = true
}
for _, rule := range rules {
if !resolved && shouldResolveIP(rule, metadata) {
ip, err := resolver.ResolveIP(metadata.Host)
if err != nil {
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 !processFound && rule.ShouldFindProcess() {
processFound = true
srcIP, ok := netip.AddrFromSlice(metadata.SrcIP)
if ok && metadata.OriginDst.IsValid() {
srcIP = srcIP.Unmap()
path, err := P.FindProcessPath(metadata.NetWork.String(), netip.AddrPortFrom(srcIP, uint16(metadata.SrcPort)), metadata.OriginDst)
if err != nil {
log.Debugln("[Process] find process %s: %v", metadata.String(), err)
} else {
log.Debugln("[Process] %s from process %s", metadata.String(), path)
metadata.ProcessPath = path
}
}
}
if rule.Match(metadata) {
adapter, ok := proxies[rule.Adapter()]
if !ok {
continue
}
if metadata.NetWork == C.UDP && !adapter.SupportUDP() && UDPFallbackMatch.Load() {
log.Debugln("[Matcher] %s UDP is not supported, skip match", adapter.Name())
continue
}
return adapter, rule, nil
}
}
return proxies["DIRECT"], nil, nil
}