104 lines
2.5 KiB
Nim
104 lines
2.5 KiB
Nim
|
## nim-ws
|
||
|
|
## Copyright (c) 2021 Status Research & Development GmbH
|
||
|
|
## Licensed under either of
|
||
|
|
## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
|
||
|
|
## * MIT license ([LICENSE-MIT](LICENSE-MIT))
|
||
|
|
## at your option.
|
||
|
|
## This file may not be copied, modified, or distributed except according to
|
||
|
|
## those terms.
|
||
|
|
|
||
|
|
import
|
||
|
|
std/[strutils],
|
||
|
|
pkg/[stew/results,
|
||
|
|
stew/byteutils,
|
||
|
|
chronos,
|
||
|
|
chronicles],
|
||
|
|
../../ws/types,
|
||
|
|
../../ws/frame
|
||
|
|
|
||
|
|
type
|
||
|
|
HexExt = ref object of Ext
|
||
|
|
transform: bool
|
||
|
|
|
||
|
|
const
|
||
|
|
extID = "hex"
|
||
|
|
|
||
|
|
method decode(ext: HexExt, frame: Frame): Future[Frame] {.async.} =
|
||
|
|
if frame.opcode notin {Opcode.Text, Opcode.Binary, Opcode.Cont}:
|
||
|
|
return frame
|
||
|
|
|
||
|
|
if frame.opcode in {Opcode.Text, Opcode.Binary}:
|
||
|
|
ext.transform = frame.rsv3
|
||
|
|
frame.rsv3 = false
|
||
|
|
|
||
|
|
if not ext.transform:
|
||
|
|
return frame
|
||
|
|
|
||
|
|
if frame.length > 0:
|
||
|
|
var data: seq[byte]
|
||
|
|
var buf: array[0xFFFF, byte]
|
||
|
|
|
||
|
|
while data.len < frame.length.int:
|
||
|
|
let len = min(frame.length.int - data.len, buf.len)
|
||
|
|
let read = await frame.read(ext.session.stream.reader, addr buf[0], len)
|
||
|
|
data.add toOpenArray(buf, 0, read - 1)
|
||
|
|
|
||
|
|
if data.len > ext.session.frameSize:
|
||
|
|
raise newException(WSPayloadTooLarge, "payload exceeds allowed max frame size")
|
||
|
|
|
||
|
|
frame.data = hexToSeqByte(cast[string](data))
|
||
|
|
trace "HexExt decode", input=frame.length, output=frame.data.len
|
||
|
|
|
||
|
|
frame.length = frame.data.len.uint64
|
||
|
|
frame.offset = 0
|
||
|
|
frame.consumed = 0
|
||
|
|
frame.mask = false
|
||
|
|
|
||
|
|
return frame
|
||
|
|
|
||
|
|
method encode(ext: HexExt, frame: Frame): Future[Frame] {.async.} =
|
||
|
|
if frame.opcode notin {Opcode.Text, Opcode.Binary, Opcode.Cont}:
|
||
|
|
return frame
|
||
|
|
|
||
|
|
if frame.opcode in {Opcode.Text, Opcode.Binary}:
|
||
|
|
ext.transform = true
|
||
|
|
frame.rsv3 = ext.transform
|
||
|
|
|
||
|
|
if not ext.transform:
|
||
|
|
return frame
|
||
|
|
|
||
|
|
frame.length = frame.data.len.uint64
|
||
|
|
frame.data = cast[seq[byte]](toHex(frame.data))
|
||
|
|
trace "HexExt encode", input=frame.length, output=frame.data.len
|
||
|
|
|
||
|
|
frame.length = frame.data.len.uint64
|
||
|
|
frame.offset = 0
|
||
|
|
frame.consumed = 0
|
||
|
|
|
||
|
|
return frame
|
||
|
|
|
||
|
|
method toHttpOptions(ext: HexExt): string =
|
||
|
|
extID
|
||
|
|
|
||
|
|
proc hexFactory*(): ExtFactory =
|
||
|
|
|
||
|
|
proc factory(isServer: bool,
|
||
|
|
args: seq[ExtParam]): Result[Ext, string] {.
|
||
|
|
gcsafe, raises: [Defect].} =
|
||
|
|
|
||
|
|
# you can capture configuration variables via closure
|
||
|
|
# if you want
|
||
|
|
|
||
|
|
var ext = HexExt(
|
||
|
|
name : extID,
|
||
|
|
transform: false
|
||
|
|
)
|
||
|
|
|
||
|
|
ok(ext)
|
||
|
|
|
||
|
|
ExtFactory(
|
||
|
|
name: extID,
|
||
|
|
factory: factory,
|
||
|
|
clientOffer: extID
|
||
|
|
)
|