Message-Id: <2E8F0DD1-DB1E-40D7-9ACD-9900C5D65704@holtmann.org>
Date:   Mon, 23 Mar 2020 19:05:33 +0100
From:   Marcel Holtmann <marcel@...tmann.org>
To:     Miao-chen Chou <mcchou@...omium.org>
Cc:     Bluetooth Kernel Mailing List <linux-bluetooth@...r.kernel.org>,
        Luiz Augusto von Dentz <luiz.von.dentz@...el.com>,
        Alain Michaud <alainm@...omium.org>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        Johan Hedberg <johan.hedberg@...il.com>,
        linux-kernel@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: [PATCH v1 2/2] Bluetooth: btusb: Read the supported features of
 Microsoft vendor extension

Hi Miao-chen,

> This adds a new header to facilitate the opcode and packet structures of
> vendor extension(s). For now, we add only the
> HCI_VS_MSFT_Read_Supported_Features command from Microsoft vendor
> extension. See https://docs.microsoft.com/en-us/windows-hardware/drivers/
> bluetooth/microsoft-defined-bluetooth-hci-commands-and-events#
> microsoft-defined-bluetooth-hci-events for more details.
> Upon initialization of a hci_dev, we issue a
> HCI_VS_MSFT_Read_Supported_Features command to read the supported features
> of Microsoft vendor extension if the opcode of Microsoft vendor extension
> is valid. See https://docs.microsoft.com/en-us/windows-hardware/drivers/
> bluetooth/microsoft-defined-bluetooth-hci-commands-and-events#
> hci_vs_msft_read_supported_features for more details.
> This was verified on a device with Intel ThhunderPeak BT controller where
> the Microsoft vendor extension features are 0x000000000000003f.
> 
> Signed-off-by: Miao-chen Chou <mcchou@...omium.org>
> ---
> 
> Changes in v1:
> - Add vendor_hci.h to facilitate opcodes and packet structures of vendor
> extension(s).

Put the structs directly into hci_msft.c and try to isolate all commands into that file. And prefix everything with msft_.

> - Add opcode for the HCI_VS_MSFT_Read_Supported_Features command from
> Microsoft vendor extension.
> - Issue a HCI_VS_MSFT_Read_Supported_Features command upon
> hci_dev_do_open and save the return values.
> 
> include/net/bluetooth/hci_core.h   |  1 +
> include/net/bluetooth/vendor_hci.h | 51 ++++++++++++++++++++++++++++++
> net/bluetooth/hci_core.c           | 30 ++++++++++++++++++
> net/bluetooth/hci_event.c          | 49 +++++++++++++++++++++++++++-
> 4 files changed, 130 insertions(+), 1 deletion(-)
> create mode 100644 include/net/bluetooth/vendor_hci.h
> 
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index 15daf3b2d4f0..941e71bdad42 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -30,6 +30,7 @@
> 
> #include <net/bluetooth/hci.h>
> #include <net/bluetooth/hci_sock.h>
> +#include <net/bluetooth/vendor_hci.h>
> 
> /* HCI priority */
> #define HCI_PRIO_MAX	7
> diff --git a/include/net/bluetooth/vendor_hci.h b/include/net/bluetooth/vendor_hci.h
> new file mode 100644
> index 000000000000..bd374a7bf976
> --- /dev/null
> +++ b/include/net/bluetooth/vendor_hci.h
> @@ -0,0 +1,51 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * BlueZ - Bluetooth protocol stack for Linux
> + * Copyright (C) 2020 Google Corporation
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation;
> + *
> + * 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 OF THIRD PARTY RIGHTS.
> + * IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
> + * CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
> + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
> + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
> + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
> + *
> + * ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
> + * COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
> + * SOFTWARE IS DISCLAIMED.
> + */
> +
> +#ifndef __VENDOR_HCI_H
> +#define __VENDOR_HCI_H
> +
> +#define MSFT_EVT_PREFIX_MAX_LEN				255
> +
> +struct msft_cmd_cmp_info {
> +	__u8 status;
> +	__u8 sub_opcode;
> +} __packed;
> +
> +/* Microsoft Vendor HCI subcommands */
> +#define MSFT_OP_READ_SUPPORTED_FEATURES			0x00
> +#define MSFT_FEATURE_MASK_RSSI_MONITOR_BREDR_CONN	0x0000000000000001
> +#define MSFT_FEATURE_MASK_RSSI_MONITOR_LE_CONN		0x0000000000000002
> +#define MSFT_FEATURE_MASK_RSSI_MONITOR_LE_ADV		0x0000000000000004
> +#define MSFT_FEATURE_MASK_ADV_MONITOR_LE_ADV		0x0000000000000008
> +#define MSFT_FEATURE_MASK_VERIFY_CURVE_			0x0000000000000010
> +#define MSFT_FEATURE_MASK_CONCURRENT_ADV_MONITOR	0x0000000000000020
> +struct msft_cp_read_supported_features {
> +	__u8 sub_opcode;
> +} __packed;
> +struct msft_rp_read_supported_features {
> +	__u64 features;
> +	__u8  msft_evt_prefix_len;
> +	__u8  msft_evt_prefix[0];
> +} __packed;
> +
> +#endif /* __VENDOR_HCI_H */
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index dbd2ad3a26ed..3cec58ca0047 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -1407,6 +1407,32 @@ static void hci_dev_get_bd_addr_from_property(struct hci_dev *hdev)
> 	bacpy(&hdev->public_addr, &ba);
> }
> 
> +static int hci_msft_read_supported_features_req(struct hci_request *req,
> +						unsigned long opt)
> +{
> +	struct hci_dev *hdev = req->hdev;
> +	struct msft_cp_read_supported_features cp;
> +
> +	if (hdev->msft_vnd_ext_opcode == HCI_OP_NOP)
> +		return -EOPNOTSUPP;
> +
> +	cp.sub_opcode = MSFT_OP_READ_SUPPORTED_FEATURES;
> +	hci_req_add(req, hdev->msft_vnd_ext_opcode, sizeof(cp), &cp);
> +	return 0;
> +}
> +
> +static void read_vendor_extension_features(struct hci_dev *hdev)
> +{
> +	int err;
> +
> +	if (hdev->msft_vnd_ext_opcode !=  HCI_OP_NOP) {
> +		err = __hci_req_sync(hdev, hci_msft_read_supported_features_req,
> +				     0, HCI_CMD_TIMEOUT, NULL);
> +		if (err)
> +			BT_ERR("HCI_VS_MSFT_Read_Supported_Feature failed");
> +	}
> +}
> +
> static int hci_dev_do_open(struct hci_dev *hdev)
> {
> 	int ret = 0;
> @@ -1572,6 +1598,10 @@ static int hci_dev_do_open(struct hci_dev *hdev)
> 		set_bit(HCI_UP, &hdev->flags);
> 		hci_sock_dev_event(hdev, HCI_DEV_UP);
> 		hci_leds_update_powered(hdev, true);
> +
> +		/* Check features supported by HCI extensions. */
> +		read_vendor_extension_features(hdev);
> +

Lets not do this after the HCI_DEV_UP event. You need to do this after the init sequence has executed.

> 		if (!hci_dev_test_flag(hdev, HCI_SETUP) &&
> 		    !hci_dev_test_flag(hdev, HCI_CONFIG) &&
> 		    !hci_dev_test_flag(hdev, HCI_UNCONFIGURED) &&
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 20408d386268..6a156167dfc9 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -23,7 +23,6 @@
> */
> 
> /* Bluetooth HCI event handling. */
> -

This change doesn’t belong here.

> #include <asm/unaligned.h>
> 
> #include <net/bluetooth/bluetooth.h>
> @@ -1787,6 +1786,47 @@ static void hci_cc_write_ssp_debug_mode(struct hci_dev *hdev, struct sk_buff *sk
> 		hdev->ssp_debug_mode = *mode;
> }
> 
> +static void hci_cc_msft_vnd_ext(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> +	struct msft_cmd_cmp_info *info = (void *)skb->data;
> +	const u8 status = info->status;
> +	const u16 sub_opcode = __le16_to_cpu(info->sub_opcode);
> +
> +	skb_pull(skb, sizeof(*info));
> +
> +	if (status) {
> +		BT_ERR("Microsoft vendor extension sub command 0x%2.2x failed",
> +		       sub_opcode);
> +		return;
> +	}
> +
> +	BT_DBG("%s status 0x%2.2x sub opcode 0x%2.2x", hdev->name, status,
> +	       sub_opcode);
> +
> +	switch (sub_opcode) {
> +	case MSFT_OP_READ_SUPPORTED_FEATURES: {
> +		struct msft_rp_read_supported_features *rp = (void *)skb->data;
> +
> +		hdev->msft_vnd_ext_features = __le64_to_cpu(rp->features);
> +		hdev->msft_vnd_ext_evt_prefix_len = rp->msft_evt_prefix_len;
> +		hdev->msft_vnd_ext_evt_prefix =
> +			kmalloc(hdev->msft_vnd_ext_evt_prefix_len, GFP_ATOMIC);
> +		if (!hdev->msft_vnd_ext_evt_prefix)
> +			return;
> +
> +		memcpy(hdev->msft_vnd_ext_evt_prefix, rp->msft_evt_prefix,
> +		       hdev->msft_vnd_ext_evt_prefix_len);
> +		BT_DBG("%s Microsoft vendor extension features 0x%016llx",
> +		       hdev->name, hdev->msft_vnd_ext_features);
> +		break;
> +	}
> +	default:
> +		BT_ERR("%s unknown sub opcode 0x%2.2x", hdev->name,
> +		       sub_opcode);
> +		break;
> +	}
> +}
> +
> static void hci_cs_inquiry(struct hci_dev *hdev, __u8 status)
> {
> 	BT_DBG("%s status 0x%2.2x", hdev->name, status);
> @@ -3198,6 +3238,7 @@ static void hci_cmd_complete_evt(struct hci_dev *hdev, struct sk_buff *skb,
> 				 hci_req_complete_skb_t *req_complete_skb)
> {
> 	struct hci_ev_cmd_complete *ev = (void *) skb->data;
> +	const u16 msft_vnd_ext_opcode = hdev->msft_vnd_ext_opcode;
> 
> 	*opcode = __le16_to_cpu(ev->opcode);
> 	*status = skb->data[sizeof(*ev)];
> @@ -3538,6 +3579,12 @@ static void hci_cmd_complete_evt(struct hci_dev *hdev, struct sk_buff *skb,
> 		break;
> 
> 	default:
> +		/* Check if it's a Microsoft vendor extension opcode. */
> +		if (msft_vnd_ext_opcode != HCI_OP_NOP &&
> +		    *opcode == msft_vnd_ext_opcode) {
> +			hci_cc_msft_vnd_ext(hdev, skb);
> +			break;
> +		}
> 		BT_DBG("%s opcode 0x%4.4x", hdev->name, *opcode);
> 		break;
> 	}

For now we only have synchronous commands. The features reading can be done with sync call.

Regards

Marcel

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