Linux: Allow connecting Wiimotes via L2CAP (#1353)

src/input/api/Wiimote/l2cap/L2CapWiimote.cpp

@@ -0,0 +1,148 @@
+#include "L2CapWiimote.h"
+#include <bluetooth/l2cap.h>
+
+constexpr auto comparator = [](const bdaddr_t& a, const bdaddr_t& b) {
+	return bacmp(&a, &b);
+};
+
+static auto s_addresses = std::map<bdaddr_t, bool, decltype(comparator)>(comparator);
+static std::mutex s_addressMutex;
+
+static bool AttemptConnect(int sockFd, const sockaddr_l2& addr)
+{
+	auto res = connect(sockFd, reinterpret_cast<const sockaddr*>(&addr),
+					   sizeof(sockaddr_l2));
+	if (res == 0)
+		return true;
+	return connect(sockFd, reinterpret_cast<const sockaddr*>(&addr),
+				   sizeof(sockaddr_l2)) == 0;
+}
+
+static bool AttemptSetNonBlock(int sockFd)
+{
+	return fcntl(sockFd, F_SETFL, fcntl(sockFd, F_GETFL) | O_NONBLOCK) == 0;
+}
+
+L2CapWiimote::L2CapWiimote(int recvFd, int sendFd, bdaddr_t addr)
+	: m_recvFd(recvFd), m_sendFd(sendFd), m_addr(addr)
+{
+}
+
+L2CapWiimote::~L2CapWiimote()
+{
+	close(m_recvFd);
+	close(m_sendFd);
+	const auto& b = m_addr.b;
+	cemuLog_logDebug(LogType::Force, "Wiimote at {:02x}:{:02x}:{:02x}:{:02x}:{:02x}:{:02x} disconnected", b[5], b[4], b[3], b[2], b[1], b[0]);
+
+	// Re-add to candidate vec
+	s_addressMutex.lock();
+	s_addresses[m_addr] = false;
+	s_addressMutex.unlock();
+}
+
+void L2CapWiimote::AddCandidateAddress(bdaddr_t addr)
+{
+	std::scoped_lock lock(s_addressMutex);
+	s_addresses.try_emplace(addr, false);
+}
+
+std::vector<WiimoteDevicePtr> L2CapWiimote::get_devices()
+{
+	s_addressMutex.lock();
+	std::vector<bdaddr_t> unconnected;
+	for (const auto& [addr, connected] : s_addresses)
+	{
+		if (!connected)
+			unconnected.push_back(addr);
+	}
+	s_addressMutex.unlock();
+
+	std::vector<WiimoteDevicePtr> outDevices;
+	for (const auto& addr : unconnected)
+	{
+		// Socket for sending data to controller, PSM 0x11
+		auto sendFd = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);
+		if (sendFd < 0)
+		{
+			cemuLog_logDebug(LogType::Force, "Failed to open send socket: {}", strerror(errno));
+			continue;
+		}
+
+		sockaddr_l2 sendAddr{};
+		sendAddr.l2_family = AF_BLUETOOTH;
+		sendAddr.l2_psm = htobs(0x11);
+		sendAddr.l2_bdaddr = addr;
+
+		if (!AttemptConnect(sendFd, sendAddr) || !AttemptSetNonBlock(sendFd))
+		{
+			const auto& b = addr.b;
+			cemuLog_logDebug(LogType::Force, "Failed to connect send socket to '{:02x}:{:02x}:{:02x}:{:02x}:{:02x}:{:02x}': {}",
+							 b[5], b[4], b[3], b[2], b[1], b[0], strerror(errno));
+			close(sendFd);
+			continue;
+		}
+
+		// Socket for receiving data from controller, PSM 0x13
+		auto recvFd = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);
+		if (recvFd < 0)
+		{
+			cemuLog_logDebug(LogType::Force, "Failed to open recv socket: {}", strerror(errno));
+			close(sendFd);
+			continue;
+		}
+		sockaddr_l2 recvAddr{};
+		recvAddr.l2_family = AF_BLUETOOTH;
+		recvAddr.l2_psm = htobs(0x13);
+		recvAddr.l2_bdaddr = addr;
+
+		if (!AttemptConnect(recvFd, recvAddr) || !AttemptSetNonBlock(recvFd))
+		{
+			const auto& b = addr.b;
+			cemuLog_logDebug(LogType::Force, "Failed to connect recv socket to '{:02x}:{:02x}:{:02x}:{:02x}:{:02x}:{:02x}': {}",
+							 b[5], b[4], b[3], b[2], b[1], b[0], strerror(errno));
+			close(sendFd);
+			close(recvFd);
+			continue;
+		}
+		outDevices.emplace_back(std::make_shared<L2CapWiimote>(sendFd, recvFd, addr));
+
+		s_addressMutex.lock();
+		s_addresses[addr] = true;
+		s_addressMutex.unlock();
+	}
+	return outDevices;
+}
+
+bool L2CapWiimote::write_data(const std::vector<uint8>& data)
+{
+	const auto size = data.size();
+	cemu_assert_debug(size < 23);
+	uint8 buffer[23];
+	// All outgoing messages must be prefixed with 0xA2
+	buffer[0] = 0xA2;
+	std::memcpy(buffer + 1, data.data(), size);
+	const auto outSize = size + 1;
+	return send(m_sendFd, buffer, outSize, 0) == outSize;
+}
+
+std::optional<std::vector<uint8>> L2CapWiimote::read_data()
+{
+	uint8 buffer[23];
+	const auto nBytes = recv(m_sendFd, buffer, 23, 0);
+
+	if (nBytes < 0 && errno == EWOULDBLOCK)
+		return std::vector<uint8>{};
+	// All incoming messages must be prefixed with 0xA1
+	if (nBytes < 2 || buffer[0] != 0xA1)
+		return std::nullopt;
+	return std::vector(buffer + 1, buffer + 1 + nBytes - 1);
+}
+
+bool L2CapWiimote::operator==(const WiimoteDevice& rhs) const
+{
+	auto mote = dynamic_cast<const L2CapWiimote*>(&rhs);
+	if (!mote)
+		return false;
+	return bacmp(&m_addr, &mote->m_addr) == 0;
+}