netdev - [PATCH v2 1/2] Bluetooth: btusb: define HCI packet sizes of USB Alts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Wed,  9 Sep 2020 17:42:01 +0800
From:   Joseph Hwang <josephsih@...omium.org>
To:     linux-bluetooth@...r.kernel.org, marcel@...tmann.org,
        luiz.dentz@...il.com
Cc:     chromeos-bluetooth-upstreaming@...omium.org, josephsih@...gle.com,
        Joseph Hwang <josephsih@...omium.org>,
        Alain Michaud <alainm@...omium.org>,
        Abhishek Pandit-Subedi <abhishekpandit@...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: [PATCH v2 1/2] Bluetooth: btusb: define HCI packet sizes of USB Alts

It is desirable to define the HCI packet payload sizes of
USB alternate settings so that they can be exposed to user
space.

Reviewed-by: Alain Michaud <alainm@...omium.org>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@...omium.org>
Signed-off-by: Joseph Hwang <josephsih@...omium.org>
---

Changes in v2:
- 1/2: Used sco_mtu instead of a new sco_pkt_len member in hdev.
- 1/2: Do not overwrite hdev->sco_mtu in hci_cc_read_buffer_size
  if it has been set in the USB interface.
- 2/2: Used BT_SNDMTU/BT_RCVMTU instead of creating a new opt name.
- 2/2: Used the existing conn->mtu instead of creating a new member
       in struct sco_pinfo.
- 2/2: Noted that the old SCO_OPTIONS in sco_sock_getsockopt_old()
       would just work as it uses sco_pi(sk)->conn->mtu.

 drivers/bluetooth/btusb.c | 43 +++++++++++++++++++++++++++++----------
 net/bluetooth/hci_event.c |  7 ++++++-
 2 files changed, 38 insertions(+), 12 deletions(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index fe80588c7bd3a8..a710233382afff 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -459,6 +459,22 @@ static const struct dmi_system_id btusb_needs_reset_resume_table[] = {
 #define BTUSB_WAKEUP_DISABLE	14
 #define BTUSB_USE_ALT1_FOR_WBS	15
 
+/* Per core spec 5, vol 4, part B, table 2.1,
+ * list the hci packet payload sizes for various ALT settings.
+ * This is used to set the packet length for the wideband speech.
+ * If a controller does not probe its usb alt setting, the default
+ * value will be 0. Any clients at upper layers should interpret it
+ * as a default value and set a proper packet length accordingly.
+ *
+ * To calculate the HCI packet payload length:
+ *   for alternate settings 1 - 5:
+ *     hci_packet_size = suggested_max_packet_size * 3 (packets) -
+ *                       3 (HCI header octets)
+ *   for alternate setting 6:
+ *     hci_packet_size = suggested_max_packet_size - 3 (HCI header octets)
+ */
+static const int hci_packet_size_usb_alt[] = { 0, 24, 48, 72, 96, 144, 60 };
+
 struct btusb_data {
 	struct hci_dev       *hdev;
 	struct usb_device    *udev;
@@ -3959,6 +3975,15 @@ static int btusb_probe(struct usb_interface *intf,
 	hdev->notify = btusb_notify;
 	hdev->prevent_wake = btusb_prevent_wake;
 
+	if (id->driver_info & BTUSB_AMP) {
+		/* AMP controllers do not support SCO packets */
+		data->isoc = NULL;
+	} else {
+		/* Interface orders are hardcoded in the specification */
+		data->isoc = usb_ifnum_to_if(data->udev, ifnum_base + 1);
+		data->isoc_ifnum = ifnum_base + 1;
+	}
+
 #ifdef CONFIG_PM
 	err = btusb_config_oob_wake(hdev);
 	if (err)
@@ -4022,6 +4047,10 @@ static int btusb_probe(struct usb_interface *intf,
 		hdev->set_diag = btintel_set_diag;
 		hdev->set_bdaddr = btintel_set_bdaddr;
 		hdev->cmd_timeout = btusb_intel_cmd_timeout;
+
+		if (btusb_find_altsetting(data, 6))
+			hdev->sco_mtu = hci_packet_size_usb_alt[6];
+
 		set_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks);
 		set_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks);
 		set_bit(HCI_QUIRK_NON_PERSISTENT_DIAG, &hdev->quirks);
@@ -4063,15 +4092,6 @@ static int btusb_probe(struct usb_interface *intf,
 		btusb_check_needs_reset_resume(intf);
 	}
 
-	if (id->driver_info & BTUSB_AMP) {
-		/* AMP controllers do not support SCO packets */
-		data->isoc = NULL;
-	} else {
-		/* Interface orders are hardcoded in the specification */
-		data->isoc = usb_ifnum_to_if(data->udev, ifnum_base + 1);
-		data->isoc_ifnum = ifnum_base + 1;
-	}
-
 	if (IS_ENABLED(CONFIG_BT_HCIBTUSB_RTL) &&
 	    (id->driver_info & BTUSB_REALTEK)) {
 		hdev->setup = btrtl_setup_realtek;
@@ -4083,9 +4103,10 @@ static int btusb_probe(struct usb_interface *intf,
 		 * (DEVICE_REMOTE_WAKEUP)
 		 */
 		set_bit(BTUSB_WAKEUP_DISABLE, &data->flags);
-		if (btusb_find_altsetting(data, 1))
+		if (btusb_find_altsetting(data, 1)) {
 			set_bit(BTUSB_USE_ALT1_FOR_WBS, &data->flags);
-		else
+			hdev->sco_mtu = hci_packet_size_usb_alt[1];
+		} else
 			bt_dev_err(hdev, "Device does not support ALT setting 1");
 	}
 
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 33d8458fdd4adc..b3e9247fdbcfa1 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -730,7 +730,12 @@ static void hci_cc_read_buffer_size(struct hci_dev *hdev, struct sk_buff *skb)
 		return;
 
 	hdev->acl_mtu  = __le16_to_cpu(rp->acl_mtu);
-	hdev->sco_mtu  = rp->sco_mtu;
+	/* Set sco_mtu only when not yet.
+	 * The sco_mtu would be set in btusb.c
+	 * if the host controller interface is USB.
+	 */
+	if (hdev->sco_mtu == 0)
+		hdev->sco_mtu  = rp->sco_mtu;
 	hdev->acl_pkts = __le16_to_cpu(rp->acl_max_pkt);
 	hdev->sco_pkts = __le16_to_cpu(rp->sco_max_pkt);
 
-- 
2.28.0.526.ge36021eeef-goog