prevent interleaved channel data

This commit is contained in:
Dmitriy Ryajov 2019-09-07 17:34:11 -06:00
parent 8c76799d9e
commit 65ce1a93fc
1 changed files with 30 additions and 14 deletions

View File

@ -7,7 +7,7 @@
## This file may not be copied, modified, or distributed except according to
## those terms.
import chronos
import chronos, options, sequtils
import types,
../../connection,
../../varint,
@ -16,33 +16,42 @@ import types,
nimcrypto/utils
type
Phase = enum Header, Size
Msg* = tuple
id: uint
msgType: MessageType
data: seq[byte]
proc readMplexVarint(conn: Connection): Future[uint] {.async, gcsafe.} =
proc readMplexVarint(conn: Connection): Future[Option[uint]] {.async, gcsafe.} =
var
varint: uint
length: int
res: VarintStatus
var buffer = newSeq[byte](10)
result = none(uint)
try:
for i in 0..<len(buffer):
await conn.readExactly(addr buffer[i], 1)
res = LP.getUVarint(buffer.toOpenArray(0, i), length, varint)
if res == VarintStatus.Success:
return varint
return some(varint)
if res != VarintStatus.Success:
buffer.setLen(0)
return
except TransportIncompleteError, AsyncStreamIncompleteError:
buffer.setLen(0)
proc readMsg*(conn: Connection): Future[(uint, MessageType, seq[byte])] {.async, gcsafe.} =
let header = await conn.readMplexVarint()
let dataLen = await conn.readMplexVarint()
proc readMsg*(conn: Connection): Future[Option[Msg]] {.async, gcsafe.} =
let headerVarint = await conn.readMplexVarint()
if headerVarint.isNone:
return
let dataLenVarint = await conn.readMplexVarint()
var data: seq[byte]
if dataLen > 0.uint:
data = await conn.read(dataLen.int)
result = (header shr 3, MessageType(header and 0x7), data)
if dataLenVarint.isSome and dataLenVarint.get() > 0.uint:
data = await conn.read(dataLenVarint.get().int)
let header = headerVarint.get()
result = some((header shr 3, MessageType(header and 0x7), data))
proc writeMsg*(conn: Connection,
id: uint,
@ -50,7 +59,14 @@ proc writeMsg*(conn: Connection,
data: seq[byte] = @[]) {.async, gcsafe.} =
## write lenght prefixed
var buf = initVBuffer()
buf.writeVarint((id shl 3) or ord(msgType).uint)
let header = (id shl 3 or ord(msgType).uint)
buf.writeVarint(id shl 3 or ord(msgType).uint)
buf.writeVarint(data.len().uint) # size should be always sent
buf.finish()
await conn.write(buf.buffer & data)
proc writeMsg*(conn: Connection,
id: uint,
msgType: MessageType,
data: string) {.async, gcsafe.} =
result = conn.writeMsg(id, msgType, cast[seq[byte]](toSeq(data.items)))