Websocket Server in C++ Error on sending message - c++

Question

I've been developing a C++ websocket server and it's working pretty good, except for one error that I don't understand.
The thing is that I can receive data and perform actions claimed by web browsers, but supposing that the server needs to send back some info, the first time it's sent succesfully, but when I repeat the same request (or another one which needs information back to browser), my server tries to send it (apparently successfully), then by itself sends it again (I don't know why) and then the connection is closed.
here's my code for sending messages:
int CSocketNode::SendMsg(const char opr, const char* cad,int length){
if (socket_conn == INVALID_SOCKET)
return -1;
int pos = 0;
int result = 0;
memset(Buffer_out, 0, BUFFER_SIZE);
if(!webSocket){
//Build header
Buffer_out[pos] = 57; //12345 % 256;
Buffer_out[pos + 1] = 48; //12345 / 256;
length++;
if((length / 256) >= 256){
int divi = length / 256;
Buffer_out[pos + 2] = length % 256;
Buffer_out[pos + 3] = divi % 256;
Buffer_out[pos + 4] = divi / 256;
} else {
Buffer_out[pos + 2] = length % 256;
Buffer_out[pos + 3] = 0;
Buffer_out[pos + 4] = length / 256;
}
Buffer_out[pos + 5] = opr;
pos = 5;
memcpy(Buffer_out + pos + 1, cad, length);
} else {
Buffer_out[pos++] = 0x81;
length++;
if(length <= 125){
Buffer_out[pos++] = length;
} else if(length <= 65535) {
Buffer_out[pos++] = 126;
Buffer_out[pos++] = (length >> 8) & 0xff;
Buffer_out[pos++] = length & 0xff;
} else {
Buffer_out[pos++] = 127;
memset(Buffer_out + pos, 0, 8);
for (int i = 7; i >= 0; i--){
Buffer_out[pos++] = (length >> 8*i) & 0xff;
}
}
Buffer_out[pos++] = opr;
memcpy(Buffer_out + pos, cad, length);
}
printf("0: %d, 1: %d, 2: %d, 3: %d, 4: %d. Pos = %d\n", Buffer_out[0], Buffer_out[1], Buffer_out[2], Buffer_out[3], Buffer_out[4], pos);
printf("%s\n", Buffer_out + pos);
result = SendBytes(Buffer_out, length + pos);
return result;
}
int CSocketNode::SendBytes(char *cad, int length){
//Send it
int err = send(socket_conn, cad, length,0);
if (err == SOCKET_ERROR ){
Error("SendBytes Error");
return -1;
}
return 0;
}
The first part of the IF sentence is for my non web browser clients, which works perfectly.
no matter what size the data frame is, less than 125 or less than 65535, the result is the same.
maybe I'm missing something. Maybe I havve to add and a FIN message at the wnd of the message. but according to the WebSocket Manual, it is the first bit of the message which indicates if it's the or not of multiple messages.
If you can tell me what it is I will be very thankful.

Answer 1

Solved it by myself. For some reason that I cannot guess, the memcpy makes the socket pipe not work correctly.
So I used a for loop to copy the message to the buffer. And solved.