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package encoding
import (
"encoding/binary"
"io"
"v2ray.com/core/common"
"v2ray.com/core/common/buf"
"v2ray.com/core/common/net"
"v2ray.com/core/common/protocol"
"v2ray.com/core/common/serial"
"v2ray.com/core/common/uuid"
)
var (
ErrCommandTypeMismatch = newError("Command type mismatch.")
ErrUnknownCommand = newError("Unknown command.")
ErrCommandTooLarge = newError("Command too large.")
)
func MarshalCommand(command interface{}, writer io.Writer) error {
if command == nil {
return ErrUnknownCommand
}
var cmdID byte
var factory CommandFactory
switch command.(type) {
case *protocol.CommandSwitchAccount:
factory = new(CommandSwitchAccountFactory)
cmdID = 1
default:
return ErrUnknownCommand
}
buffer := buf.New()
defer buffer.Release()
err := factory.Marshal(command, buffer)
if err != nil {
return err
}
auth := Authenticate(buffer.Bytes())
length := buffer.Len() + 4
if length > 255 {
return ErrCommandTooLarge
}
common.Must2(writer.Write([]byte{cmdID, byte(length), byte(auth >> 24), byte(auth >> 16), byte(auth >> 8), byte(auth)}))
common.Must2(writer.Write(buffer.Bytes()))
return nil
}
func UnmarshalCommand(cmdID byte, data []byte) (protocol.ResponseCommand, error) {
if len(data) <= 4 {
return nil, newError("insufficient length")
}
expectedAuth := Authenticate(data[4:])
actualAuth := binary.BigEndian.Uint32(data[:4])
if expectedAuth != actualAuth {
return nil, newError("invalid auth")
}
var factory CommandFactory
switch cmdID {
case 1:
factory = new(CommandSwitchAccountFactory)
default:
return nil, ErrUnknownCommand
}
return factory.Unmarshal(data[4:])
}
type CommandFactory interface {
Marshal(command interface{}, writer io.Writer) error
Unmarshal(data []byte) (interface{}, error)
}
type CommandSwitchAccountFactory struct {
}
func (f *CommandSwitchAccountFactory) Marshal(command interface{}, writer io.Writer) error {
cmd, ok := command.(*protocol.CommandSwitchAccount)
if !ok {
return ErrCommandTypeMismatch
}
hostStr := ""
if cmd.Host != nil {
hostStr = cmd.Host.String()
}
common.Must2(writer.Write([]byte{byte(len(hostStr))}))
if len(hostStr) > 0 {
common.Must2(writer.Write([]byte(hostStr)))
}
common.Must2(serial.WriteUint16(writer, cmd.Port.Value()))
idBytes := cmd.ID.Bytes()
common.Must2(writer.Write(idBytes))
common.Must2(serial.WriteUint16(writer, cmd.AlterIds))
common.Must2(writer.Write([]byte{byte(cmd.Level)}))
common.Must2(writer.Write([]byte{cmd.ValidMin}))
return nil
}
func (f *CommandSwitchAccountFactory) Unmarshal(data []byte) (interface{}, error) {
cmd := new(protocol.CommandSwitchAccount)
if len(data) == 0 {
return nil, newError("insufficient length.")
}
lenHost := int(data[0])
if len(data) < lenHost+1 {
return nil, newError("insufficient length.")
}
if lenHost > 0 {
cmd.Host = net.ParseAddress(string(data[1 : 1+lenHost]))
}
portStart := 1 + lenHost
if len(data) < portStart+2 {
return nil, newError("insufficient length.")
}
cmd.Port = net.PortFromBytes(data[portStart : portStart+2])
idStart := portStart + 2
if len(data) < idStart+16 {
return nil, newError("insufficient length.")
}
cmd.ID, _ = uuid.ParseBytes(data[idStart : idStart+16])
alterIDStart := idStart + 16
if len(data) < alterIDStart+2 {
return nil, newError("insufficient length.")
}
cmd.AlterIds = binary.BigEndian.Uint16(data[alterIDStart : alterIDStart+2])
levelStart := alterIDStart + 2
if len(data) < levelStart+1 {
return nil, newError("insufficient length.")
}
cmd.Level = uint32(data[levelStart])
timeStart := levelStart + 1
if len(data) < timeStart+1 {
return nil, newError("insufficient length.")
}
cmd.ValidMin = data[timeStart]
return cmd, nil
}
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