Implement direct_bt: Direct Bluetooth access via Linux's Kernel BlueZ protocol stack w/o D-Bus bluetoothd.

By dropping BlueZ userspace D-Bus bluetoothd, we target high-performance reliable bluetooth support
with least dependencies for embedded device configurations.

See COPYING, describing which Linux Kernel BlueZ IOCTL information has been included in the source tree.
We claim Linus Torvalds's Linux Kernel license exception regarding kernel syscalls (ioctl):
<https://github.com/torvalds/linux/blob/master/LICENSES/exceptions/Linux-syscall-note>
and hence maintain this project's license.

The new direct_bt feature set is organized as follows
- include/cppunit
- api/direct_bt
- api/ieee11073
- src/direct_bt
- examples/direct_bt

Note that the C++ direct_bt layer is not backward compatible to tinyb.

Since the Java layer still needs to be completed,
it has to be seen whether we will achieve compatibility
or drop the original D-Bus tinyb module altogether
in favor of a more streamlined API and implementation.

Current state allows scanning for LE devices, connecting
and parsing GATT plus receiving notifications and indications.
See examples/direct_bt_scanner/dbt_scanner.cpp.

The Linux Kernel BlueZ is configured via module MgmtComm.[hpp/cpp]

1 files changed, 330 insertions, 0 deletions

diff --git a/api/direct_bt/BTIoctl.hpp b/api/direct_bt/BTIoctl.hpp
new file mode 100644
index 00000000..b410152b
--- /dev/null
+++ b/api/direct_bt/BTIoctl.hpp
@@ -0,0 +1,330 @@
+/*
+ * Copyright (C) 2000-2001  Qualcomm Incorporated
+ * Copyright (C) 2002-2003  Maxim Krasnyansky <[email protected]>
+ * Copyright (C) 2002-2010  Marcel Holtmann <[email protected]>
+ * Copyright (c) 2020 Gothel Software e.K.
+ * Copyright (c) 2020 ZAFENA AB
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * ****************************************************************************************
+ * ****************************************************************************************
+ * ****************************************************************************************
+ *
+ * This file imports certain information from Linux Kernel's BlueZ protocol stack,
+ * allowing the use of these kernel services via system calls.
+ * Therefore, the license has been aligned with this project.
+ * See file COPYING in the root folder of this project for more details,
+ * as well as Linus Torvalds's Linux Kernel license exception regarding kernel syscalls (ioctl):
+ * <https://github.com/torvalds/linux/blob/master/LICENSES/exceptions/Linux-syscall-note>.
+ *
+ * Original sources:
+ * linux-kernel 4.19 include/net/bluetooth/bluetooth.h (git head 8d368fc58e7aeb42b39d7bec7c585efdfbc49074).
+ *
+ * Original copyright:
+ * BlueZ - Bluetooth protocol stack for Linux
+ * Copyright (C) 2000-2001 Qualcomm Incorporated
+ * Written 2000,2001 by Maxim Krasnyansky <[email protected]>
+ */
+
+#ifndef BT_IOCTL_HPP_
+#define BT_IOCTL_HPP_
+
+#include "BTAddress.hpp"
+
+#include "linux_kernel_types.hpp"
+
+extern "C" {
+    #include <stdint.h>
+    #include <endian.h>
+    #include <byteswap.h>
+    #include <netinet/in.h> // Already exported named by OS
+} /* extern "C" */
+
+/**
+ * Information from include/net/bluetooth/bluetooth.h
+ */
+
+#ifndef AF_BLUETOOTH
+#define AF_BLUETOOTH	31
+#define PF_BLUETOOTH	AF_BLUETOOTH
+#endif
+
+/* Bluetooth versions */
+#define BLUETOOTH_VER_1_1	1
+#define BLUETOOTH_VER_1_2	2
+#define BLUETOOTH_VER_2_0	3
+
+#define BTPROTO_L2CAP	0
+#define BTPROTO_HCI	1
+#define BTPROTO_SCO	2
+#define BTPROTO_RFCOMM	3
+#define BTPROTO_BNEP	4
+#define BTPROTO_CMTP	5
+#define BTPROTO_HIDP	6
+#define BTPROTO_AVDTP	7
+
+#define SOL_HCI		0
+#define SOL_L2CAP	6
+#define SOL_SCO		17
+#define SOL_RFCOMM	18
+
+#define BT_SECURITY	4
+struct bt_security {
+	__u8 level;
+	__u8 key_size;
+};
+#define BT_SECURITY_SDP		0
+#define BT_SECURITY_LOW		1
+#define BT_SECURITY_MEDIUM	2
+#define BT_SECURITY_HIGH	3
+#define BT_SECURITY_FIPS	4
+
+#define BT_DEFER_SETUP	7
+
+#define BT_FLUSHABLE	8
+
+#define BT_FLUSHABLE_OFF	0
+#define BT_FLUSHABLE_ON		1
+
+#define BT_POWER	9
+struct bt_power {
+	__u8 force_active;
+};
+#define BT_POWER_FORCE_ACTIVE_OFF 0
+#define BT_POWER_FORCE_ACTIVE_ON  1
+
+#define BT_CHANNEL_POLICY	10
+
+/* BR/EDR only (default policy)
+ *   AMP controllers cannot be used.
+ *   Channel move requests from the remote device are denied.
+ *   If the L2CAP channel is currently using AMP, move the channel to BR/EDR.
+ */
+#define BT_CHANNEL_POLICY_BREDR_ONLY		0
+
+/* BR/EDR Preferred
+ *   Allow use of AMP controllers.
+ *   If the L2CAP channel is currently on AMP, move it to BR/EDR.
+ *   Channel move requests from the remote device are allowed.
+ */
+#define BT_CHANNEL_POLICY_BREDR_PREFERRED	1
+
+/* AMP Preferred
+ *   Allow use of AMP controllers
+ *   If the L2CAP channel is currently on BR/EDR and AMP controller
+ *     resources are available, initiate a channel move to AMP.
+ *   Channel move requests from the remote device are allowed.
+ *   If the L2CAP socket has not been connected yet, try to create
+ *     and configure the channel directly on an AMP controller rather
+ *     than BR/EDR.
+ */
+#define BT_CHANNEL_POLICY_AMP_PREFERRED		2
+
+#define BT_VOICE		11
+struct bt_voice {
+	__u16 setting;
+};
+
+#define BT_VOICE_TRANSPARENT			0x0003
+#define BT_VOICE_CVSD_16BIT			0x0060
+
+#define BT_SNDMTU		12
+#define BT_RCVMTU		13
+
+/* Connection and socket states */
+enum {
+	BT_CONNECTED = 1, /* Equal to TCP_ESTABLISHED to make net code happy */
+	BT_OPEN,
+	BT_BOUND,
+	BT_LISTEN,
+	BT_CONNECT,
+	BT_CONNECT2,
+	BT_CONFIG,
+	BT_DISCONN,
+	BT_CLOSED
+};
+
+/**
+ * Additional ordinary helpers ..
+ */
+
+/* Byte order conversions */
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define htobs(d)  (d)
+#define htobl(d)  (d)
+#define htobll(d) (d)
+#define btohs(d)  (d)
+#define btohl(d)  (d)
+#define btohll(d) (d)
+#elif __BYTE_ORDER == __BIG_ENDIAN
+#define htobs(d)  bswap_16(d)
+#define htobl(d)  bswap_32(d)
+#define htobll(d) bswap_64(d)
+#define btohs(d)  bswap_16(d)
+#define btohl(d)  bswap_32(d)
+#define btohll(d) bswap_64(d)
+#else
+#error "Unknown byte order"
+#endif
+
+/* Bluetooth unaligned access */
+#define bt_get_unaligned(ptr)			\
+__extension__ ({				\
+	struct __attribute__((packed)) {	\
+		__typeof__(*(ptr)) __v;		\
+	} *__p = (__typeof__(__p)) (ptr);	\
+	__p->__v;				\
+})
+
+#define bt_put_unaligned(val, ptr)		\
+do {						\
+	struct __attribute__((packed)) {	\
+		__typeof__(*(ptr)) __v;		\
+	} *__p = (__typeof__(__p)) (ptr);	\
+	__p->__v = (val);			\
+} while(0)
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+static inline uint64_t bt_get_le64(const void *ptr)
+{
+	return bt_get_unaligned((const uint64_t *) ptr);
+}
+
+static inline uint64_t bt_get_be64(const void *ptr)
+{
+	return bswap_64(bt_get_unaligned((const uint64_t *) ptr));
+}
+
+static inline uint32_t bt_get_le32(const void *ptr)
+{
+	return bt_get_unaligned((const uint32_t *) ptr);
+}
+
+static inline uint32_t bt_get_be32(const void *ptr)
+{
+	return bswap_32(bt_get_unaligned((const uint32_t *) ptr));
+}
+
+static inline uint16_t bt_get_le16(const void *ptr)
+{
+	return bt_get_unaligned((const uint16_t *) ptr);
+}
+
+static inline uint16_t bt_get_be16(const void *ptr)
+{
+	return bswap_16(bt_get_unaligned((const uint16_t *) ptr));
+}
+
+static inline void bt_put_le64(uint64_t val, const void *ptr)
+{
+	bt_put_unaligned(val, (uint64_t *) ptr);
+}
+
+static inline void bt_put_be64(uint64_t val, const void *ptr)
+{
+	bt_put_unaligned(bswap_64(val), (uint64_t *) ptr);
+}
+
+static inline void bt_put_le32(uint32_t val, const void *ptr)
+{
+	bt_put_unaligned(val, (uint32_t *) ptr);
+}
+
+static inline void bt_put_be32(uint32_t val, const void *ptr)
+{
+	bt_put_unaligned(bswap_32(val), (uint32_t *) ptr);
+}
+
+static inline void bt_put_le16(uint16_t val, const void *ptr)
+{
+	bt_put_unaligned(val, (uint16_t *) ptr);
+}
+
+static inline void bt_put_be16(uint16_t val, const void *ptr)
+{
+	bt_put_unaligned(bswap_16(val), (uint16_t *) ptr);
+}
+
+#elif __BYTE_ORDER == __BIG_ENDIAN
+static inline uint64_t bt_get_le64(const void *ptr)
+{
+	return bswap_64(bt_get_unaligned((const uint64_t *) ptr));
+}
+
+static inline uint64_t bt_get_be64(const void *ptr)
+{
+	return bt_get_unaligned((const uint64_t *) ptr);
+}
+
+static inline uint32_t bt_get_le32(const void *ptr)
+{
+	return bswap_32(bt_get_unaligned((const uint32_t *) ptr));
+}
+
+static inline uint32_t bt_get_be32(const void *ptr)
+{
+	return bt_get_unaligned((const uint32_t *) ptr);
+}
+
+static inline uint16_t bt_get_le16(const void *ptr)
+{
+	return bswap_16(bt_get_unaligned((const uint16_t *) ptr));
+}
+
+static inline uint16_t bt_get_be16(const void *ptr)
+{
+	return bt_get_unaligned((const uint16_t *) ptr);
+}
+
+static inline void bt_put_le64(uint64_t val, const void *ptr)
+{
+	bt_put_unaligned(bswap_64(val), (uint64_t *) ptr);
+}
+
+static inline void bt_put_be64(uint64_t val, const void *ptr)
+{
+	bt_put_unaligned(val, (uint64_t *) ptr);
+}
+
+static inline void bt_put_le32(uint32_t val, const void *ptr)
+{
+	bt_put_unaligned(bswap_32(val), (uint32_t *) ptr);
+}
+
+static inline void bt_put_be32(uint32_t val, const void *ptr)
+{
+	bt_put_unaligned(val, (uint32_t *) ptr);
+}
+
+static inline void bt_put_le16(uint16_t val, const void *ptr)
+{
+	bt_put_unaligned(bswap_16(val), (uint16_t *) ptr);
+}
+
+static inline void bt_put_be16(uint16_t val, const void *ptr)
+{
+	bt_put_unaligned(val, (uint16_t *) ptr);
+}
+#else
+#error "Unknown byte order"
+#endif
+
+#endif /* BT_IOCTL_HPP_ */