mirror of
https://github.com/nadoo/glider.git
synced 2025-04-11 14:53:15 +08:00
107 lines
2.9 KiB
Go
107 lines
2.9 KiB
Go
// MIT License
|
|
//
|
|
// Copyright (c) 2016-2017 xtaci
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
// of this software and associated documentation files (the "Software"), to deal
|
|
// in the Software without restriction, including without limitation the rights
|
|
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
// copies of the Software, and to permit persons to whom the Software is
|
|
// furnished to do so, subject to the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be included in all
|
|
// copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
// SOFTWARE.
|
|
|
|
package smux
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"fmt"
|
|
)
|
|
|
|
const ( // cmds
|
|
// protocol version 1:
|
|
cmdSYN byte = iota // stream open
|
|
cmdFIN // stream close, a.k.a EOF mark
|
|
cmdPSH // data push
|
|
cmdNOP // no operation
|
|
|
|
// protocol version 2 extra commands
|
|
// notify bytes consumed by remote peer-end
|
|
cmdUPD
|
|
)
|
|
|
|
const (
|
|
// data size of cmdUPD, format:
|
|
// |4B data consumed(ACK)| 4B window size(WINDOW) |
|
|
szCmdUPD = 8
|
|
)
|
|
|
|
const (
|
|
// initial peer window guess, a slow-start
|
|
initialPeerWindow = 262144
|
|
)
|
|
|
|
const (
|
|
sizeOfVer = 1
|
|
sizeOfCmd = 1
|
|
sizeOfLength = 2
|
|
sizeOfSid = 4
|
|
headerSize = sizeOfVer + sizeOfCmd + sizeOfSid + sizeOfLength
|
|
)
|
|
|
|
// Frame defines a packet from or to be multiplexed into a single connection
|
|
type Frame struct {
|
|
ver byte // version
|
|
cmd byte // command
|
|
sid uint32 // stream id
|
|
data []byte // payload
|
|
}
|
|
|
|
// newFrame creates a new frame with given version, command and stream id
|
|
func newFrame(version byte, cmd byte, sid uint32) Frame {
|
|
return Frame{ver: version, cmd: cmd, sid: sid}
|
|
}
|
|
|
|
// rawHeader is a byte array representation of Frame header
|
|
type rawHeader [headerSize]byte
|
|
|
|
func (h rawHeader) Version() byte {
|
|
return h[0]
|
|
}
|
|
|
|
func (h rawHeader) Cmd() byte {
|
|
return h[1]
|
|
}
|
|
|
|
func (h rawHeader) Length() uint16 {
|
|
return binary.LittleEndian.Uint16(h[2:])
|
|
}
|
|
|
|
func (h rawHeader) StreamID() uint32 {
|
|
return binary.LittleEndian.Uint32(h[4:])
|
|
}
|
|
|
|
func (h rawHeader) String() string {
|
|
return fmt.Sprintf("Version:%d Cmd:%d StreamID:%d Length:%d",
|
|
h.Version(), h.Cmd(), h.StreamID(), h.Length())
|
|
}
|
|
|
|
// updHeader is a byte array representation of cmdUPD
|
|
type updHeader [szCmdUPD]byte
|
|
|
|
func (h updHeader) Consumed() uint32 {
|
|
return binary.LittleEndian.Uint32(h[:])
|
|
}
|
|
func (h updHeader) Window() uint32 {
|
|
return binary.LittleEndian.Uint32(h[4:])
|
|
}
|