Method parseheader

src/dpp/wsclient.cpp:203–295

}

bool websocket_client::parseheader(std::string& data)
{
	if (data.size() < 4) {
		/* Not enough data to form a frame yet */
		return false;
	}

	unsigned char opcode = data[0];
	switch (opcode & ~WS_FINBIT) {
		case OP_CONTINUATION:
		case OP_TEXT:
		case OP_BINARY:
		case OP_PING:
		case OP_PONG: {
			unsigned char len1 = data[1];
			unsigned int payloadstartoffset = 2;

			if (len1 & WS_MASKBIT) {
				len1 &= ~WS_MASKBIT;
				payloadstartoffset += 2;
				/* We don't handle masked data, because discord doesn't send it */
				return true;
			}

			/* 6 bit ("small") length frame */
			uint64_t len = len1;

			if (len1 == WS_PAYLOAD_LENGTH_MAGIC_LARGE) {
				/* 24 bit ("large") length frame */
				if (data.length() < 8) {
					/* We don't have a complete header yet */
					return false;
				}

				unsigned char len2 = (unsigned char)data[2];
				unsigned char len3 = (unsigned char)data[3];
				len = (len2 << 8) | len3;

				payloadstartoffset += 2;
			} else if (len1 == WS_PAYLOAD_LENGTH_MAGIC_HUGE) {
				/* 64 bit ("huge") length frame */
				if (data.length() < 10) {
					/* We don't have a complete header yet */
					return false;
				}
				len = 0;
				for (int v = 2, shift = 56; v < 10; ++v, shift -= 8) {
					unsigned char l = (unsigned char)data[v];
					len |= (uint64_t)(l & 0xff) << shift;
				}
				payloadstartoffset += 8;
			}

			if (data.length() < payloadstartoffset + len) {
				/* We don't have a complete frame yet */
				return false;
			}