HI Marcel,
On Thu, Apr 2, 2020 at 9:30 AM Marcel Holtmann <marcel@xxxxxxxxxxxx> wrote:
>
> To allow userspace to make correcty security policy decision, the kernel
> needs to export a few details of the supported security features and
> encryption key size information. This command exports this information
> and also allows future extensions if needed.
>
> Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
> ---
> include/net/bluetooth/mgmt.h | 7 +++++
> net/bluetooth/mgmt.c | 53 ++++++++++++++++++++++++++++++++++++
> 2 files changed, 60 insertions(+)
>
> diff --git a/include/net/bluetooth/mgmt.h b/include/net/bluetooth/mgmt.h
> index f41cd87550dc..65dd6fd1fff3 100644
> --- a/include/net/bluetooth/mgmt.h
> +++ b/include/net/bluetooth/mgmt.h
> @@ -674,6 +674,13 @@ struct mgmt_cp_set_blocked_keys {
>
> #define MGMT_OP_SET_WIDEBAND_SPEECH 0x0047
>
> +#define MGMT_OP_READ_SECURITY_INFO 0x0048
> +#define MGMT_READ_SECURITY_INFO_SIZE 0
> +struct mgmt_rp_read_security_info {
> + __le16 sec_len;
> + __u8 sec[0];
> +} __packed;
> +
> #define MGMT_EV_CMD_COMPLETE 0x0001
> struct mgmt_ev_cmd_complete {
> __le16 opcode;
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index 6552003a170e..7b9eac339c87 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -108,6 +108,7 @@ static const u16 mgmt_commands[] = {
> MGMT_OP_SET_APPEARANCE,
> MGMT_OP_SET_BLOCKED_KEYS,
> MGMT_OP_SET_WIDEBAND_SPEECH,
> + MGMT_OP_READ_SECURITY_INFO,
> };
>
> static const u16 mgmt_events[] = {
> @@ -155,6 +156,7 @@ static const u16 mgmt_untrusted_commands[] = {
> MGMT_OP_READ_CONFIG_INFO,
> MGMT_OP_READ_EXT_INDEX_LIST,
> MGMT_OP_READ_EXT_INFO,
> + MGMT_OP_READ_SECURITY_INFO,
> };
>
> static const u16 mgmt_untrusted_events[] = {
> @@ -3659,6 +3661,55 @@ static int set_wideband_speech(struct sock *sk, struct hci_dev *hdev,
> return err;
> }
>
> +static int read_security_info(struct sock *sk, struct hci_dev *hdev,
> + void *data, u16 data_len)
> +{
> + char buf[16];
> + struct mgmt_rp_read_security_info *rp = (void *)buf;
> + u16 sec_len = 0;
> + u8 flags = 0;
> +
> + bt_dev_dbg(hdev, "sock %p", sk);
> +
> + memset(&buf, 0, sizeof(buf));
> +
> + hci_dev_lock(hdev);
> +
> + /* When the Read Simple Pairing Options command is supported, then
> + * the remote public key validation is supported.
> + */
> + if (hdev->commands[41] & 0x08)
> + flags |= 0x01; /* Remote public key validation (BR/EDR) */
> +
> + flags |= 0x02; /* Remote public key validation (LE) */
> +
> + /* When the Read Encryption Key Size command is supported, then the
> + * encryption key size is enforced.
> + */
> + if (hdev->commands[20] & 0x10)
> + flags |= 0x04; /* Encryption key size enforcement (BR/EDR) */
> +
> + flags |= 0x08; /* Encryption key size enforcement (LE) */
> +
> + sec_len = eir_append_data(rp->sec, sec_len, 0x01, &flags, 1);
> +
> + /* When the Read Simple Pairing Options command is supported, then
> + * also max encryption key size information is provided.
> + */
> + if (hdev->commands[41] & 0x08)
> + sec_len = eir_append_le16(rp->sec, sec_len, 0x02,
> + hdev->max_enc_key_size);
> +
> + sec_len = eir_append_le16(rp->sec, sec_len, 0x03, SMP_MAX_ENC_KEY_SIZE);
> +
> + rp->sec_len = cpu_to_le16(sec_len);
> +
> + hci_dev_unlock(hdev);
> +
> + return mgmt_cmd_complete(sk, hdev->id, MGMT_OP_READ_SECURITY_INFO, 0,
> + rp, sizeof(*rp) + sec_len);
> +}
> +
> static void read_local_oob_data_complete(struct hci_dev *hdev, u8 status,
> u16 opcode, struct sk_buff *skb)
> {
> @@ -7099,6 +7150,8 @@ static const struct hci_mgmt_handler mgmt_handlers[] = {
> { set_blocked_keys, MGMT_OP_SET_BLOCKED_KEYS_SIZE,
> HCI_MGMT_VAR_LEN },
> { set_wideband_speech, MGMT_SETTING_SIZE },
> + { read_security_info, MGMT_READ_SECURITY_INFO_SIZE,
> + HCI_MGMT_UNTRUSTED },
> };
>
> void mgmt_index_added(struct hci_dev *hdev)
> --
> 2.25.1
>
LGTM.
