Re: [RFCv1 2/3] Bluetooth: Simplify num_comp_pkts_evt function

[Marcel Holtmann <marcel@holtmann.org>]

Hi Andrei,

> > > Simplify function and remove fourth level of indentation.
> > > 
> > > Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
> > > ---
> > >  net/bluetooth/hci_event.c |   43 +++++++++++++++++++++++++------------------
> > >  1 files changed, 25 insertions(+), 18 deletions(-)
> > > 
> > > diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> > > index 273e1cb..fd7e6b5 100644
> > > --- a/net/bluetooth/hci_event.c
> > > +++ b/net/bluetooth/hci_event.c
> > > @@ -2288,28 +2288,35 @@ static inline void hci_num_comp_pkts_evt(struct hci_dev *hdev, struct sk_buff *s
> > >  		count  = get_unaligned_le16(ptr++);
> > 
> > actually we first need a cleanup of this function. This part is
> > horrible. It works because of our ptr cast to uint16, but we should
> > actually use a proper struct here. Maybe an info struct like we use for
> > inquiry result might be helpful here.
> 
> Something like the code below?
> 
> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> index e33e468..403974c 100644
> --- a/include/net/bluetooth/hci.h
> +++ b/include/net/bluetooth/hci.h
> @@ -1018,9 +1018,14 @@ struct hci_ev_role_change {
>  } __packed;
>  
>  #define HCI_EV_NUM_COMP_PKTS           0x13
> +struct hci_comp_pkts_info {
> +       __le16   handle;
> +       __le16   count;
> +} __packed;
> +
>  struct hci_ev_num_comp_pkts {
>         __u8     num_hndl;
> -       /* variable length part */
> +       struct hci_comp_pkts_info handles[0];
>  } __packed;
>  
>  #define HCI_EV_MODE_CHANGE             0x14
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 238fb65..079b94f 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -2273,26 +2273,27 @@ static inline void hci_role_change_evt(struct
> hci_dev *hdev, struct sk_buff *skb
>  static inline void hci_num_comp_pkts_evt(struct hci_dev *hdev, struct
> sk_buff *skb)
>  {
>         struct hci_ev_num_comp_pkts *ev = (void *) skb->data;
> -       __le16 *ptr;
> +       struct hci_comp_pkts_info *info;
>         int i;
>  
>         skb_pull(skb, sizeof(*ev));
>  
>         BT_DBG("%s num_hndl %d", hdev->name, ev->num_hndl);
>  
> -       if (skb->len < ev->num_hndl * 4) {
> +       if (skb->len < ev->num_hndl * sizeof(*info)) {
>                 BT_DBG("%s bad parameters", hdev->name);
>                 return;
>         }
>  
>         tasklet_disable(&hdev->tx_task);
>  
> -       for (i = 0, ptr = (__le16 *) skb->data; i < ev->num_hndl; i++) {
> +       for (i = 0; i < ev->num_hndl; i++) {

		struct hci_comp_pkts_info *info = &ev->handles[i];

>                 struct hci_conn *conn;
>                 __u16  handle, count;
>  
> -               handle = get_unaligned_le16(ptr++);
> -               count  = get_unaligned_le16(ptr++);
> +               info = &ev->handles[i];
> +               handle = __le16_to_cpu(info->handle);
> +               count  = __le16_to_cpu(info->count);
>  
>                 conn = hci_conn_hash_lookup_handle(hdev, handle);
>                 if (!conn)

And you need to remove the skb_pull above since otherwise you are
pointing to the wrong memory location.

Regards

Marcel