websockets fails with messages over 16bits

[alanswx]

in: https://github.com/davidmoreno/onion/blob/master/src/onion/websocket.c#L207
header[3 + 8 - i] = tlen & 0x0FF;

I am pretty sure the 3 should be a 1:

header[1 + 8 - i] = tlen & 0x0FF;

There may also be a 32 vs 64 bit problem on systems where int isn't 64 bits.

[YggdrasiI]

I think this old issue can be closed.

The assumption that header[3+X] needs to be changed to header[1+X] is wrong: The size will be stored two bytes after the opcode (reference https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API/Writing_WebSocket_servers )

The 64bit width of size_t is still a problem, so for unrealistic big packages the type
of len should be changed to ssize_t, too.

onion/src/onion/websocket.c

Line 205 in 2b3b230

int tlen = len;