Files
Xray-core/proxy/shadowsocks_2022/inbound_relay.go
T
2026-09-24 22:00:36 +08:00

339 lines
9.0 KiB
Go

package shadowsocks_2022
import (
"context"
"crypto/cipher"
"encoding/binary"
"io"
"strconv"
"time"
"github.com/xtls/xray-core/common"
"github.com/xtls/xray-core/common/buf"
"github.com/xtls/xray-core/common/errors"
"github.com/xtls/xray-core/common/log"
"github.com/xtls/xray-core/common/net"
"github.com/xtls/xray-core/common/protocol"
"github.com/xtls/xray-core/common/session"
"github.com/xtls/xray-core/common/signal"
"github.com/xtls/xray-core/common/task"
"github.com/xtls/xray-core/common/utils"
"github.com/xtls/xray-core/common/uuid"
"github.com/xtls/xray-core/core"
"github.com/xtls/xray-core/features/policy"
"github.com/xtls/xray-core/features/routing"
"github.com/xtls/xray-core/transport/internet/stat"
)
func init() {
common.Must(common.RegisterConfig((*RelayServerConfig)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
return NewRelayServer(ctx, config.(*RelayServerConfig))
}))
}
type relayDest struct {
destination net.Destination
email string
level uint32
key []byte
blockCipher cipher.Block
}
type RelayInbound struct {
networks []net.Network
method *CipherMethod
relayPSK []byte
relayBlock cipher.Block
destinations map[[AESBlockSize]byte]*relayDest
rawDestinations []*RelayDestination
policyManager policy.Manager
}
func NewRelayServer(ctx context.Context, config *RelayServerConfig) (*RelayInbound, error) {
networks := config.Network
if len(networks) == 0 {
networks = []net.Network{
net.Network_TCP,
net.Network_UDP,
}
}
method, err := GetCipherMethod(config.Method)
if err != nil {
return nil, err
}
if method.IsChaCha {
return nil, errors.New("shadowsocks 2022 relay: only aes methods are supported")
}
relayPSK, err := ParseKey(config.Key, method.KeySaltLength)
if err != nil {
return nil, err
}
relayBlock, err := method.NewBlock(relayPSK)
if err != nil {
return nil, err
}
v := core.MustFromContext(ctx)
i := &RelayInbound{
networks: networks,
method: method,
relayPSK: relayPSK,
relayBlock: relayBlock,
destinations: make(map[[AESBlockSize]byte]*relayDest),
rawDestinations: config.Destinations,
policyManager: v.GetFeature(policy.ManagerType()).(policy.Manager),
}
for idx, d := range config.Destinations {
if d.Email == "" {
u := uuid.New()
d.Email = "unnamed-destination-" + strconv.Itoa(idx) + "-" + u.String()
}
destKey, err := ParseKey(d.Key, method.KeySaltLength)
if err != nil {
return nil, err
}
destBlock, err := method.NewBlock(destKey)
if err != nil {
return nil, err
}
hash := DeriveUserPSKHash(destKey)
i.destinations[hash] = &relayDest{
destination: net.TCPDestination(d.Address.AsAddress(), net.Port(d.Port)),
email: d.Email,
level: uint32(d.Level),
key: destKey,
blockCipher: destBlock,
}
}
return i, nil
}
func (i *RelayInbound) Network() []net.Network {
return i.networks
}
func (i *RelayInbound) Process(ctx context.Context, network net.Network, connection stat.Connection, dispatcher routing.Dispatcher) error {
inbound := session.InboundFromContext(ctx)
inbound.Name = "shadowsocks-2022-relay"
inbound.CanSpliceCopy = 3
if network == net.Network_TCP {
return i.processTCP(ctx, connection, dispatcher)
}
return i.processUDP(ctx, connection, dispatcher)
}
func (i *RelayInbound) processTCP(ctx context.Context, conn net.Conn, dispatcher routing.Dispatcher) error {
defer conn.Close()
sessionPolicy := i.policyManager.ForLevel(0)
if err := conn.SetReadDeadline(time.Now().Add(sessionPolicy.Timeouts.Handshake)); err != nil {
return errors.New("unable to set read deadline").Base(err).AtWarning()
}
// Read Salt + Outer EIH
needed := i.method.KeySaltLength + AESBlockSize
var headerBuf [48]byte
headerSlice := headerBuf[:needed]
if _, err := io.ReadFull(conn, headerSlice); err != nil {
return err
}
salt := headerSlice[:i.method.KeySaltLength]
eih := headerSlice[i.method.KeySaltLength:]
identitySubkey := DeriveIdentitySubKey(i.relayPSK, salt, i.method.KeySaltLength)
block, err := i.method.NewBlock(identitySubkey)
if err != nil {
return err
}
var decryptedHash [AESBlockSize]byte
block.Decrypt(decryptedHash[:], eih)
targetDest, ok := i.destinations[decryptedHash]
if !ok {
return ErrInvalidRequest
}
_ = conn.SetReadDeadline(time.Time{})
inbound := session.InboundFromContext(ctx)
if inbound == nil {
inbound = new(session.Inbound)
ctx = session.ContextWithInbound(ctx, inbound)
}
inbound.User = &protocol.MemoryUser{
Email: targetDest.email,
Level: targetDest.level,
}
ctx = log.ContextWithAccessMessage(ctx, &log.AccessMessage{
From: conn.RemoteAddr(),
To: targetDest.destination,
Status: log.AccessAccepted,
Email: targetDest.email,
})
errors.LogInfo(ctx, "relaying connection to ", targetDest.destination)
link, err := dispatcher.Dispatch(ctx, targetDest.destination)
if err != nil {
return err
}
// Unwrap outer EIH: send client salt to next hop, stripping this hop's EIH
saltBuf := buf.New()
saltBuf.Write(salt)
if err := link.Writer.WriteMultiBuffer(buf.MultiBuffer{saltBuf}); err != nil {
return err
}
sessionPolicy = i.policyManager.ForLevel(targetDest.level)
ctx, cancel := context.WithCancel(ctx)
timer := signal.CancelAfterInactivity(ctx, cancel, sessionPolicy.Timeouts.ConnectionIdle)
ctx = policy.ContextWithBufferPolicy(ctx, sessionPolicy.Buffer)
requestDone := func() error {
defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
return buf.Copy(buf.NewReader(conn), link.Writer, buf.UpdateActivity(timer))
}
responseDone := func() error {
defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly)
return buf.Copy(link.Reader, buf.NewWriter(conn), buf.UpdateActivity(timer))
}
responseDoneAndCloseWriter := task.OnSuccess(responseDone, task.Close(link.Writer))
return task.Run(ctx, requestDone, responseDoneAndCloseWriter)
}
func (i *RelayInbound) processUDP(ctx context.Context, conn stat.Connection, dispatcher routing.Dispatcher) error {
udpConns := utils.NewTypedSyncMap[uint64, *udpConnEntry]()
defer func() {
udpConns.Range(func(key uint64, entry *udpConnEntry) bool {
entry.timer.SetTimeout(0)
return true
})
}()
reader := buf.NewReader(conn)
for {
mb, err := reader.ReadMultiBuffer()
if err != nil {
buf.ReleaseMulti(mb)
return err
}
for _, b := range mb {
data := b.Bytes()
if len(data) < 2*AESBlockSize {
b.Release()
continue
}
var packetHeader [AESBlockSize]byte
i.relayBlock.Decrypt(packetHeader[:], data[:AESBlockSize])
var eiHeader [AESBlockSize]byte
i.relayBlock.Decrypt(eiHeader[:], data[AESBlockSize:2*AESBlockSize])
for idx := 0; idx < AESBlockSize; idx++ {
eiHeader[idx] ^= packetHeader[idx]
}
targetDest, ok := i.destinations[eiHeader]
if !ok {
b.Release()
continue
}
// Extract sessionID from raw packetHeader for session-level link caching before re-encrypting
sessionID := binary.BigEndian.Uint64(packetHeader[:8])
// Re-encrypt packetHeader with next hop block cipher
targetDest.blockCipher.Encrypt(packetHeader[:], packetHeader[:])
// Strip outer EIH: replace second block with re-encrypted packetHeader and advance
copy(data[AESBlockSize:2*AESBlockSize], packetHeader[:])
b.Advance(int32(AESBlockSize))
dest := targetDest.destination
dest.Network = net.Network_UDP
entry, ok := udpConns.Load(sessionID)
if !ok {
sessCtx, cancel := context.WithCancel(ctx)
inbound := session.InboundFromContext(sessCtx)
if inbound == nil {
inbound = new(session.Inbound)
sessCtx = session.ContextWithInbound(sessCtx, inbound)
}
inbound.User = &protocol.MemoryUser{
Email: targetDest.email,
Level: targetDest.level,
}
sessCtx = log.ContextWithAccessMessage(sessCtx, &log.AccessMessage{
From: conn.RemoteAddr(),
To: dest,
Status: log.AccessAccepted,
Email: targetDest.email,
})
link, err := dispatcher.Dispatch(sessCtx, dest)
if err != nil {
cancel()
b.Release()
continue
}
newEntry := &udpConnEntry{
link: link,
cancel: cancel,
}
sessionPolicy := i.policyManager.ForLevel(targetDest.level)
newEntry.timer = signal.CancelAfterInactivity(sessCtx, func() {
udpConns.Delete(sessionID)
common.Interrupt(link.Reader)
common.Interrupt(link.Writer)
cancel()
}, sessionPolicy.Timeouts.ConnectionIdle)
actual, loaded := udpConns.LoadOrStore(sessionID, newEntry)
if loaded {
newEntry.timer.SetTimeout(0)
entry = actual
} else {
entry = newEntry
go func(cEntry *udpConnEntry) {
defer func() {
cEntry.timer.SetTimeout(0)
}()
for {
resMb, err := cEntry.link.Reader.ReadMultiBuffer()
if err != nil {
return
}
cEntry.timer.Update()
for _, rb := range resMb {
_, _ = conn.Write(rb.Bytes())
rb.Release()
}
}
}(entry)
}
}
entry.timer.Update()
_ = entry.link.Writer.WriteMultiBuffer(buf.MultiBuffer{b})
}
}
}