public WsFrame(
Fin fin, Opcode opcode, Mask mask, PayloadData payload, bool compressed)
{
Fin = fin;
Rsv1 = isData(opcode) && compressed ? Rsv.ON : Rsv.OFF;
Rsv2 = Rsv.OFF;
Rsv3 = Rsv.OFF;
Opcode = opcode;
Mask = mask;
/* PayloadLen */
var dataLen = payload.Length;
var payloadLen = dataLen < 126
? (byte)dataLen
: dataLen < 0x010000
? (byte)126
: (byte)127;
PayloadLen = payloadLen;
/* ExtPayloadLen */
ExtPayloadLen = payloadLen < 126
? new byte [] {}
: payloadLen == 126
? ((ushort)dataLen).ToByteArrayInternally(ByteOrder.BIG)
: dataLen.ToByteArrayInternally(ByteOrder.BIG);
/* MaskingKey */
var masking = mask == Mask.MASK;
var maskingKey = masking
? createMaskingKey()
: new byte [] {};
MaskingKey = maskingKey;
/* PayloadData */
if (masking)
{
payload.Mask(maskingKey);
}
PayloadData = payload;
}
private static WsFrame parse(byte [] header, Stream stream, bool unmask)
{
/* Header */
// FIN
var fin = (header [0] & 0x80) == 0x80 ? Fin.FINAL : Fin.MORE;
// RSV1
var rsv1 = (header [0] & 0x40) == 0x40 ? Rsv.ON : Rsv.OFF;
// RSV2
var rsv2 = (header [0] & 0x20) == 0x20 ? Rsv.ON : Rsv.OFF;
// RSV3
var rsv3 = (header [0] & 0x10) == 0x10 ? Rsv.ON : Rsv.OFF;
// Opcode
var opcode = (Opcode)(header [0] & 0x0f);
// MASK
var mask = (header [1] & 0x80) == 0x80 ? Mask.MASK : Mask.UNMASK;
// Payload len
var payloadLen = (byte)(header [1] & 0x7f);
// Check if correct frame.
var incorrect = isControl(opcode) && fin == Fin.MORE
? "A control frame is fragmented."
: !isData(opcode) && rsv1 == Rsv.ON
? "A non data frame is compressed."
: null;
if (incorrect != null)
{
throw new WebSocketException(CloseStatusCode.INCORRECT_DATA, incorrect);
}
// Check if consistent frame.
if (isControl(opcode) && payloadLen > 125)
{
throw new WebSocketException(
CloseStatusCode.INCONSISTENT_DATA,
"The payload data length of a control frame is greater than 125 bytes.");
}
var frame = new WsFrame {
Fin = fin,
Rsv1 = rsv1,
Rsv2 = rsv2,
Rsv3 = rsv3,
Opcode = opcode,
Mask = mask,
PayloadLen = payloadLen
};
/* Extended Payload Length */
var extLen = payloadLen < 126
? 0
: payloadLen == 126
? 2
: 8;
var extPayloadLen = extLen > 0
? stream.ReadBytes(extLen)
: new byte [] {};
if (extLen > 0 && extPayloadLen.Length != extLen)
{
throw new WebSocketException(
"The 'Extended Payload Length' of a frame cannot be read from the data source.");
}
frame.ExtPayloadLen = extPayloadLen;
/* Masking Key */
var masked = mask == Mask.MASK;
var maskingKey = masked
? stream.ReadBytes(4)
: new byte [] {};
if (masked && maskingKey.Length != 4)
{
throw new WebSocketException(
"The 'Masking Key' of a frame cannot be read from the data source.");
}
frame.MaskingKey = maskingKey;
/* Payload Data */
ulong dataLen = payloadLen < 126
? payloadLen
: payloadLen == 126
? extPayloadLen.ToUInt16(ByteOrder.BIG)
: extPayloadLen.ToUInt64(ByteOrder.BIG);
byte [] data = null;
if (dataLen > 0)
{
// Check if allowable payload data length.
if (payloadLen > 126 && dataLen > PayloadData.MaxLength)
{
throw new WebSocketException(
CloseStatusCode.TOO_BIG, "The 'Payload Data' length is greater than the allowable length.");
}
data = payloadLen > 126
? stream.ReadBytes((long)dataLen, 1024)
: stream.ReadBytes((int)dataLen);
if (data.LongLength != (long)dataLen)
{
throw new WebSocketException(
"The 'Payload Data' of a frame cannot be read from the data source.");
}
}
else
{
data = new byte [] {};
}
var payload = new PayloadData(data, masked);
if (masked && unmask)
{
payload.Mask(maskingKey);
frame.Mask = Mask.UNMASK;
frame.MaskingKey = new byte [] {};
}
frame.PayloadData = payload;
return(frame);
}