private int TryFillAndReadInternalBuffer(BytesSegment bs)
{
var readBufferSize = this.ReadaheadBufferSize;
if (EnableReadaheadBuffer && (socketAvailable > bs.Len & bs.Len < readBufferSize))
{
if (readaheadScore > 0)
{
readaheadScore--;
}
if (readaheadBuffer.Bytes == null)
{
if (readaheadScore > 0)
{
return(0);
}
readaheadBuffer.Bytes = new byte[readBufferSize];
}
else if (readaheadBuffer.Bytes.Length < readBufferSize)
{
readaheadBuffer.Bytes = new byte[readBufferSize];
}
Interlocked.Increment(ref ctr.Rsync);
readaheadBuffer.Offset = 0;
readaheadBuffer.Len = readBufferSize;
var read = ReadSocketDirectSync(readaheadBuffer);
readaheadBuffer.Len = read;
if (read <= 0)
{
throw new Exception($"{this} should not happen: Socket.Receive() returns {read} when Socket.Available > 0.");
}
read = Math.Min(read, bs.Len);
readaheadBuffer.CopyTo(bs, read);
readaheadBuffer.SubSelf(read);
return(read);
}
else
{
if (readaheadScore < readaheadScoreMax)
{
if (++readaheadScore == readaheadScoreMax)
{
// There are many large reading opearations, so the internal buffer can be released now.
readaheadBuffer.Bytes = null;
}
}
return(0);
}
}
public async Task <int> ReadAsync(BytesSegment bs)
{
lock (_syncRoot) {
if (tcsNewBuffer?.IsCompleted == false)
{
throw new Exception("another recv task is running.");
}
if (buffer.Len == 0 & !recvEOF)
{
tcsNewBuffer.Reset();
}
}
if (tcsNewBuffer != null)
{
await tcsNewBuffer;
}
lock (_syncRoot) {
if (recvEOF && buffer.Len == 0)
{
return(0);
}
int read = Math.Min(bs.Len, buffer.Len);
buffer.CopyTo(bs, 0, read);
buffer.SubSelf(read);
if (buffer.Len == 0)
{
buffer = new BytesSegment();
tcsBufferEmptied.SetResult(0);
}
return(read);
}
}
private void Dequeue(BytesSegment bs, int len)
{
Queue.CopyTo(bs, len);
Queue.SubSelf(len);
if (Queue.Len == 0)
{
Queue.ResetSelf();
}
}
public AwaitableWrapper WriteAsyncR(BytesSegment bs)
{
var rSync = TryWriteNonblocking(bs);
if (rSync == bs.Len)
{
Interlocked.Increment(ref ctr.Wsync);
return(AwaitableWrapper.GetCompleted());
}
bs.SubSelf(Math.Max(rSync, 0));
return(WriteAsyncRImpl(bs));
}
public override Task WriteAsync(BytesSegment bs)
{
var rSync = TryWriteNonblocking(bs);
if (rSync == bs.Len)
{
Interlocked.Increment(ref ctr.Wsync);
return(NaiveUtils.CompletedTask);
}
bs.SubSelf(Math.Max(rSync, 0));
return(WriteAsyncImpl(bs));
}
public static void ParseServerHelloRecord(BytesSegment bs, ref ServerHello ch, out int size)
{
var payloadLen = GetRecordPayloadLength(bs, ref ch.Version);
size = 5 + payloadLen;
if (bs.Len < size)
{
return;
}
bs.SubSelf(5);
bs.Len = Math.Min(bs.Len, payloadLen);
ParseServerHello(bs, ref ch);
}
private static void ParseServerHello(BytesSegment msg, ref ServerHello hello)
{
var cur = 0;
if (msg[cur] != 2)
{
throw new Exception("Expected server hello (2), got " + msg[cur]);
}
cur++;
var msgLength = msg[cur] << 16 | msg[cur + 1] << 8 | msg[cur + 2]; cur += 3;
msg.SubSelf(4); cur = 0;
hello.Version = (ushort)(msg[cur] << 8 | msg[cur + 1]); cur += 2;
cur += 32; // skip random
cur += 1 + msg[cur]; // skip session_id
cur += 2; // skip cipher suite
cur += 1; // compression_methods
if (cur >= msgLength)
{
throw new Exception("extensionsBegin >= msgLength");
}
var extensionsLength = msg[cur] << 8 | msg[cur + 1]; cur += 2;
var extensionsEnd = cur + extensionsLength;
if (extensionsEnd > msgLength)
{
throw new Exception("extensionsEnd > msgLength");
}
while (cur < extensionsEnd)
{
var extType = (msg[cur] << 8 | msg[cur + 1]); cur += 2;
var extLen = (msg[cur] << 8 | msg[cur + 1]); cur += 2;
var extEnd = cur + extLen;
if (extEnd > extensionsEnd)
{
throw new Exception("extEnd > extensionsEnd");
}
if (extType == 0) // server_name
{
hello.SniUsed = true;
}
else if (extType == 16) // ALPN
{
var listLen = (msg[cur] << 8 | msg[cur + 1]); cur += 2;
var listEnd = cur + listLen;
if (listEnd > extEnd)
{
throw new Exception("alpnListEnd > extEnd");
}
if (cur < listEnd) // read the first item only
{
var strLen = msg[cur++];
if (cur + strLen > listEnd)
{
throw new Exception("alpnStrEnd > nameListEnd");
}
hello.Alpn = Encoding.ASCII.GetString(msg.Bytes, msg.Offset + cur, strLen);
}
}
else if (extType == 43) // supported_versions
{
if (extLen != 2)
{
throw new Exception("supported_versions extLen != 2");
}
var ver = (ushort)(msg[cur] << 8 | msg[cur + 1]); cur += 2;
hello.Version = ver;
}
cur = extEnd;
}
return;
}
private static void ParseClientHello(BytesSegment msg, ref ClientHello ch)
{
var cur = 0;
if (msg[cur] != 1)
{
throw new Exception("Expected client hello (1), got " + msg[cur]);
}
cur++;
var msgLength = msg[cur] << 16 | msg[cur + 1] << 8 | msg[cur + 2]; cur += 3;
msg.SubSelf(4); cur = 0;
ch.Version = (ushort)(msg[cur] << 8 | msg[cur + 1]); cur += 2;
cur += 32; // skip random
cur += 1 + msg[cur]; // skip session_id
cur += 2 + (msg[cur] << 8 | msg[cur + 1]); // skip cipher_suites
cur += 1 + msg[cur]; // skip compression_methods
if (cur >= msgLength)
{
throw new Exception("extensionsBegin >= msgLength");
}
var extensionsLength = msg[cur] << 8 | msg[cur + 1]; cur += 2;
var extensionsEnd = cur + extensionsLength;
if (extensionsEnd > msgLength)
{
throw new Exception("extensionsEnd > msgLength");
}
while (cur < extensionsEnd)
{
var extType = (msg[cur] << 8 | msg[cur + 1]); cur += 2;
var extLen = (msg[cur] << 8 | msg[cur + 1]); cur += 2;
var extEnd = cur + extLen;
if (extEnd > extensionsEnd)
{
throw new Exception("extEnd > extensionsEnd");
}
if (extType == 0) // server_name
{
var nameListLen = (msg[cur] << 8 | msg[cur + 1]); cur += 2;
var nameListEnd = cur + nameListLen;
if (nameListEnd > extEnd)
{
throw new Exception("nameListEnd > extEnd");
}
var nameList = new List <string>();
if (cur < nameListEnd) // read the first item only
{
if (msg[cur++] != 0) // name_type: host_name
{
throw new Exception("Not supported name type " + msg[cur]);
}
var nameLen = (msg[cur] << 8 | msg[cur + 1]); cur += 2;
if (cur + nameLen > nameListEnd)
{
throw new Exception("nameEnd > nameListEnd");
}
var str = NaiveUtils.UTF8Encoding.GetString(msg.Bytes, msg.Offset + cur, nameLen);
// TODO: check encoding
ch.Sni = str;
}
}
else if (extType == 16) // ALPN
{
var listLen = (msg[cur] << 8 | msg[cur + 1]); cur += 2;
var listEnd = cur + listLen;
if (listEnd > extEnd)
{
throw new Exception("alpnListEnd > extEnd");
}
if (cur < listEnd) // read the first item only
{
var strLen = msg[cur++];
if (cur + strLen > listEnd)
{
throw new Exception("alpnStrEnd > nameListEnd");
}
ch.Alpn = Encoding.ASCII.GetString(msg.Bytes, msg.Offset + cur, strLen);
}
}
else if (extType == 43) // supported_versions
{
var listLen = msg[cur++];
if (listLen < 2)
{
throw new Exception("listLen < 2");
}
var listEnd = cur + listLen;
if (listEnd > extEnd)
{
throw new Exception("supported_versions listEnd > extEnd");
}
while (cur < listEnd)
{
var ver = (ushort)(msg[cur] << 8 | msg[cur + 1]); cur += 2;
if (ver > ch.Version)
{
ch.Version = ver;
}
}
}
cur = extEnd;
}
return;
}
