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mirror of https://github.com/v2fly/v2ray-core.git synced 2024-10-31 00:08:08 -04:00
v2fly/proxy/vmess/vmessout.go
2015-11-03 21:26:16 +01:00

213 lines
6.1 KiB
Go

package vmess
import (
"bytes"
"crypto/md5"
"crypto/rand"
mrand "math/rand"
"net"
"sync"
"github.com/v2ray/v2ray-core/common/alloc"
v2crypto "github.com/v2ray/v2ray-core/common/crypto"
"github.com/v2ray/v2ray-core/common/log"
v2net "github.com/v2ray/v2ray-core/common/net"
"github.com/v2ray/v2ray-core/proxy/common/connhandler"
"github.com/v2ray/v2ray-core/proxy/vmess/config"
"github.com/v2ray/v2ray-core/proxy/vmess/protocol"
"github.com/v2ray/v2ray-core/proxy/vmess/protocol/user"
"github.com/v2ray/v2ray-core/transport/ray"
)
type VMessOutboundHandler struct {
vNextList []*config.OutboundTarget
vNextListUDP []*config.OutboundTarget
}
func NewVMessOutboundHandler(vNextList, vNextListUDP []*config.OutboundTarget) *VMessOutboundHandler {
return &VMessOutboundHandler{
vNextList: vNextList,
vNextListUDP: vNextListUDP,
}
}
func pickVNext(serverList []*config.OutboundTarget) (v2net.Destination, config.User) {
vNextLen := len(serverList)
if vNextLen == 0 {
panic("VMessOut: Zero vNext is configured.")
}
vNextIndex := 0
if vNextLen > 1 {
vNextIndex = mrand.Intn(vNextLen)
}
vNext := serverList[vNextIndex]
vNextUserLen := len(vNext.Accounts)
if vNextUserLen == 0 {
panic("VMessOut: Zero User account.")
}
vNextUserIndex := 0
if vNextUserLen > 1 {
vNextUserIndex = mrand.Intn(vNextUserLen)
}
vNextUser := vNext.Accounts[vNextUserIndex]
return vNext.Destination, vNextUser
}
func (handler *VMessOutboundHandler) Dispatch(firstPacket v2net.Packet, ray ray.OutboundRay) error {
vNextList := handler.vNextList
if firstPacket.Destination().IsUDP() {
vNextList = handler.vNextListUDP
}
vNextAddress, vNextUser := pickVNext(vNextList)
command := protocol.CmdTCP
if firstPacket.Destination().IsUDP() {
command = protocol.CmdUDP
}
request := &protocol.VMessRequest{
Version: protocol.Version,
User: vNextUser,
Command: command,
Address: firstPacket.Destination().Address(),
}
buffer := alloc.NewSmallBuffer()
defer buffer.Release()
v2net.ReadAllBytes(rand.Reader, buffer.Value[:36]) // 16 + 16 + 4
request.RequestIV = buffer.Value[:16]
request.RequestKey = buffer.Value[16:32]
request.ResponseHeader = buffer.Value[32:36]
return startCommunicate(request, vNextAddress, ray, firstPacket)
}
func startCommunicate(request *protocol.VMessRequest, dest v2net.Destination, ray ray.OutboundRay, firstPacket v2net.Packet) error {
conn, err := net.Dial(dest.Network(), dest.Address().String())
if err != nil {
log.Error("Failed to open %s: %v", dest.String(), err)
if ray != nil {
close(ray.OutboundOutput())
}
return err
}
log.Info("VMessOut: Tunneling request to %s via %s", request.Address.String(), dest.String())
defer conn.Close()
input := ray.OutboundInput()
output := ray.OutboundOutput()
var requestFinish, responseFinish sync.Mutex
requestFinish.Lock()
responseFinish.Lock()
go handleRequest(conn, request, firstPacket, input, &requestFinish)
go handleResponse(conn, request, output, &responseFinish, dest.IsUDP())
requestFinish.Lock()
if tcpConn, ok := conn.(*net.TCPConn); ok {
tcpConn.CloseWrite()
}
responseFinish.Lock()
return nil
}
func handleRequest(conn net.Conn, request *protocol.VMessRequest, firstPacket v2net.Packet, input <-chan *alloc.Buffer, finish *sync.Mutex) {
defer finish.Unlock()
aesStream, err := v2crypto.NewAesEncryptionStream(request.RequestKey[:], request.RequestIV[:])
if err != nil {
log.Error("VMessOut: Failed to create AES encryption stream: %v", err)
return
}
encryptRequestWriter := v2crypto.NewCryptionWriter(aesStream, conn)
buffer := alloc.NewBuffer().Clear()
buffer, err = request.ToBytes(user.NewTimeHash(user.HMACHash{}), user.GenerateRandomInt64InRange, buffer)
if err != nil {
log.Error("VMessOut: Failed to serialize VMess request: %v", err)
return
}
// Send first packet of payload together with request, in favor of small requests.
firstChunk := firstPacket.Chunk()
moreChunks := firstPacket.MoreChunks()
if firstChunk == nil && moreChunks {
firstChunk, moreChunks = <-input
}
if firstChunk != nil {
aesStream.XORKeyStream(firstChunk.Value, firstChunk.Value)
buffer.Append(firstChunk.Value)
firstChunk.Release()
_, err = conn.Write(buffer.Value)
buffer.Release()
if err != nil {
log.Error("VMessOut: Failed to write VMess request: %v", err)
return
}
}
if moreChunks {
v2net.ChanToWriter(encryptRequestWriter, input)
}
return
}
func handleResponse(conn net.Conn, request *protocol.VMessRequest, output chan<- *alloc.Buffer, finish *sync.Mutex, isUDP bool) {
defer finish.Unlock()
defer close(output)
responseKey := md5.Sum(request.RequestKey[:])
responseIV := md5.Sum(request.RequestIV[:])
aesStream, err := v2crypto.NewAesDecryptionStream(responseKey[:], responseIV[:])
if err != nil {
log.Error("VMessOut: Failed to create AES encryption stream: %v", err)
return
}
decryptResponseReader := v2crypto.NewCryptionReader(aesStream, conn)
buffer, err := v2net.ReadFrom(decryptResponseReader, nil)
if err != nil {
log.Error("VMessOut: Failed to read VMess response (%d bytes): %v", buffer.Len(), err)
return
}
if buffer.Len() < 4 || !bytes.Equal(buffer.Value[:4], request.ResponseHeader[:]) {
log.Warning("VMessOut: unexepcted response header. The connection is probably hijacked.")
return
}
log.Info("VMessOut received %d bytes from %s", buffer.Len()-4, conn.RemoteAddr().String())
buffer.SliceFrom(4)
output <- buffer
if !isUDP {
v2net.ReaderToChan(output, decryptResponseReader)
}
return
}
type VMessOutboundHandlerFactory struct {
}
func (factory *VMessOutboundHandlerFactory) Create(rawConfig interface{}) (connhandler.OutboundConnectionHandler, error) {
vOutConfig := rawConfig.(config.Outbound)
servers := make([]*config.OutboundTarget, 0, 16)
udpServers := make([]*config.OutboundTarget, 0, 16)
for _, target := range vOutConfig.Targets() {
if target.Destination.IsTCP() {
servers = append(servers, target)
}
if target.Destination.IsUDP() {
udpServers = append(udpServers, target)
}
}
return NewVMessOutboundHandler(servers, udpServers), nil
}
func init() {
connhandler.RegisterOutboundConnectionHandlerFactory("vmess", &VMessOutboundHandlerFactory{})
}