path: root/net/bluetooth/msft.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2020 Google Corporation
 */

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/mgmt.h>

#include "hci_request.h"
#include "mgmt_util.h"
#include "msft.h"

#define MSFT_RSSI_THRESHOLD_VALUE_MIN		-127
#define MSFT_RSSI_THRESHOLD_VALUE_MAX		20
#define MSFT_RSSI_LOW_TIMEOUT_MAX		0x3C

#define MSFT_OP_READ_SUPPORTED_FEATURES		0x00
struct msft_cp_read_supported_features {
	__u8   sub_opcode;
} __packed;

struct msft_rp_read_supported_features {
	__u8   status;
	__u8   sub_opcode;
	__le64 features;
	__u8   evt_prefix_len;
	__u8   evt_prefix[];
} __packed;

#define MSFT_OP_LE_MONITOR_ADVERTISEMENT	0x03
#define MSFT_MONITOR_ADVERTISEMENT_TYPE_PATTERN	0x01
struct msft_le_monitor_advertisement_pattern {
	__u8 length;
	__u8 data_type;
	__u8 start_byte;
	__u8 pattern[];
};

struct msft_le_monitor_advertisement_pattern_data {
	__u8 count;
	__u8 data[];
};

struct msft_cp_le_monitor_advertisement {
	__u8 sub_opcode;
	__s8 rssi_high;
	__s8 rssi_low;
	__u8 rssi_low_interval;
	__u8 rssi_sampling_period;
	__u8 cond_type;
	__u8 data[];
} __packed;

struct msft_rp_le_monitor_advertisement {
	__u8 status;
	__u8 sub_opcode;
	__u8 handle;
} __packed;

#define MSFT_OP_LE_CANCEL_MONITOR_ADVERTISEMENT	0x04
struct msft_cp_le_cancel_monitor_advertisement {
	__u8 sub_opcode;
	__u8 handle;
} __packed;

struct msft_rp_le_cancel_monitor_advertisement {
	__u8 status;
	__u8 sub_opcode;
} __packed;

#define MSFT_OP_LE_SET_ADVERTISEMENT_FILTER_ENABLE	0x05
struct msft_cp_le_set_advertisement_filter_enable {
	__u8 sub_opcode;
	__u8 enable;
} __packed;

struct msft_rp_le_set_advertisement_filter_enable {
	__u8 status;
	__u8 sub_opcode;
} __packed;

#define MSFT_EV_LE_MONITOR_DEVICE	0x02
struct msft_ev_le_monitor_device {
	__u8     addr_type;
	bdaddr_t bdaddr;
	__u8     monitor_handle;
	__u8     monitor_state;
} __packed;

struct msft_monitor_advertisement_handle_data {
	__u8  msft_handle;
	__u16 mgmt_handle;
	__s8 rssi_high;
	__s8 rssi_low;
	__u8 rssi_low_interval;
	__u8 rssi_sampling_period;
	__u8 cond_type;
	struct list_head list;
};

enum monitor_addr_filter_state {
	AF_STATE_IDLE,
	AF_STATE_ADDING,
	AF_STATE_ADDED,
	AF_STATE_REMOVING,
};

#define MSFT_MONITOR_ADVERTISEMENT_TYPE_ADDR	0x04
struct msft_monitor_addr_filter_data {
	__u8     msft_handle;
	__u8     pattern_handle; /* address filters pertain to */
	__u16    mgmt_handle;
	int      state;
	__s8     rssi_high;
	__s8     rssi_low;
	__u8     rssi_low_interval;
	__u8     rssi_sampling_period;
	__u8     addr_type;
	bdaddr_t bdaddr;
	struct list_head list;
};

struct msft_data {
	__u64 features;
	__u8  evt_prefix_len;
	__u8  *evt_prefix;
	struct list_head handle_map;
	struct list_head address_filters;
	__u8 resuming;
	__u8 suspending;
	__u8 filter_enabled;
	/* To synchronize add/remove address filter and monitor device event.*/
	struct mutex filter_lock;
};

bool msft_monitor_supported(struct hci_dev *hdev)
{
	return !!(msft_get_features(hdev) & MSFT_FEATURE_MASK_LE_ADV_MONITOR);
}

static bool read_supported_features(struct hci_dev *hdev,
				    struct msft_data *msft)
{
	struct msft_cp_read_supported_features cp;
	struct msft_rp_read_supported_features *rp;
	struct sk_buff *skb;

	cp.sub_opcode = MSFT_OP_READ_SUPPORTED_FEATURES;

	skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp,
			     HCI_CMD_TIMEOUT);
	if (IS_ERR(skb)) {
		bt_dev_err(hdev, "Failed to read MSFT supported features (%ld)",
			   PTR_ERR(skb));
		return false;
	}

	if (skb->len < sizeof(*rp)) {
		bt_dev_err(hdev, "MSFT supported features length mismatch");
		goto failed;
	}

	rp = (struct msft_rp_read_supported_features *)skb->data;

	if (rp->sub_opcode != MSFT_OP_READ_SUPPORTED_FEATURES)
		goto failed;

	if (rp->evt_prefix_len > 0) {
		msft->evt_prefix = kmemdup(rp->evt_prefix, rp->evt_prefix_len,
					   GFP_KERNEL);
		if (!msft->evt_prefix)
			goto failed;
	}

	msft->evt_prefix_len = rp->evt_prefix_len