Hi Archie,
> The BT qualification test SM/MAS/PKE/BV-01-C needs us to turn off
> the MITM flag when pairing, and at the same time also set the io
> capability to something other than no input no output.
>
> Currently the MITM flag is only unset when the io capability is set
> to no input no output, therefore the test cannot be executed.
>
> This patch introduces a debugfs option for controlling whether MITM
> flag should be set based on io capability.
>
> Signed-off-by: Archie Pusaka <apusaka@xxxxxxxxxxxx>
> ---
>
> include/net/bluetooth/hci.h | 1 +
> net/bluetooth/smp.c | 52 ++++++++++++++++++++++++++++++++++++-
> 2 files changed, 52 insertions(+), 1 deletion(-)
>
> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> index 79de2a659dd69..5e183487c7479 100644
> --- a/include/net/bluetooth/hci.h
> +++ b/include/net/bluetooth/hci.h
> @@ -298,6 +298,7 @@ enum {
> HCI_FORCE_STATIC_ADDR,
> HCI_LL_RPA_RESOLUTION,
> HCI_CMD_PENDING,
> + HCI_ENFORCE_MITM_SMP,
actually don’t you mean HCI_FORCE_NO_MITM? From your description, you want a toggle that disables MITM no matter what.
> __HCI_NUM_FLAGS,
> };
> diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
> index d0b695ee49f63..4fa8b112fb607 100644
> --- a/net/bluetooth/smp.c
> +++ b/net/bluetooth/smp.c
> @@ -2396,7 +2396,8 @@ int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
> /* Require MITM if IO Capability allows or the security level
> * requires it.
> */
> - if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
> + if ((hci_dev_test_flag(hcon->hdev, HCI_ENFORCE_MITM_SMP) &&
> + hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT) ||
> hcon->pending_sec_level > BT_SECURITY_MEDIUM)
> authreq |= SMP_AUTH_MITM;
/* New comment for this case ..
if (!hci_dev_test_flag(hcon->hdev, HCI_FORCE_NO_MITM)) {
/* Move comment here ..
if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT ||
hcon->pending_sec_level > BT_SECURITY_MEDIUM)
authreq |= SMP_AUTH_MITM;
}
>
> @@ -3402,6 +3403,50 @@ static const struct file_operations force_bredr_smp_fops = {
> .llseek = default_llseek,
> };
>
> +static ssize_t enforce_mitm_smp_read(struct file *file,
> + char __user *user_buf,
> + size_t count, loff_t *ppos)
> +{
> + struct hci_dev *hdev = file->private_data;
> + char buf[3];
> +
> + buf[0] = hci_dev_test_flag(hdev, HCI_ENFORCE_MITM_SMP) ? 'Y' : 'N';
> + buf[1] = '\n';
> + buf[2] = '\0';
> + return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
> +}
> +
> +static ssize_t enforce_mitm_smp_write(struct file *file,
> + const char __user *user_buf,
> + size_t count, loff_t *ppos)
> +{
> + struct hci_dev *hdev = file->private_data;
> + char buf[32];
> + size_t buf_size = min(count, (sizeof(buf) - 1));
> + bool enable;
> +
> + if (copy_from_user(buf, user_buf, buf_size))
> + return -EFAULT;
> +
> + buf[buf_size] = '\0';
> + if (strtobool(buf, &enable))
> + return -EINVAL;
> +
> + if (enable == hci_dev_test_flag(hdev, HCI_ENFORCE_MITM_SMP))
> + return -EALREADY;
> +
> + hci_dev_change_flag(hdev, HCI_ENFORCE_MITM_SMP);
> +
> + return count;
> +}
> +
> +static const struct file_operations enforce_mitm_smp_fops = {
> + .open = simple_open,
> + .read = enforce_mitm_smp_read,
> + .write = enforce_mitm_smp_write,
> + .llseek = default_llseek,
> +};
> +
> int smp_register(struct hci_dev *hdev)
> {
> struct l2cap_chan *chan;
> @@ -3426,6 +3471,11 @@ int smp_register(struct hci_dev *hdev)
>
> hdev->smp_data = chan;
>
> + /* Enforce the policy of determining MITM flag by io capabilities. */
> + hci_dev_set_flag(hdev, HCI_ENFORCE_MITM_SMP);
No. Lets keep the current behavior the default.
> + debugfs_create_file("enforce_mitm_smp", 0644, hdev->debugfs, hdev,
> + &enforce_mitm_smp_fops);
> +
And this needs to move into hci_debugfs.c.
Regards
Marcel
