Re: [PATCH v4 2/4] Bluetooth: bnep: Add support for get bnep features via ioctl

[Grzegorz Kolodziejczyk <grzegorz.kolodziejczyk@tieto.com>]

Hi Marcel,


On 1 April 2015 at 22:26, Marcel Holtmann <marcel@holtmann.org> wrote:
> Hi Grzegorz,
>
>> This is needed if user space wants to know supported bnep features
>> by kernel, e.g. if kernel supports sending response to bnep setup
>> control message. By now there is no possibility to know supported
>> features by kernel in case of bnep. Ioctls allows only to add connection,
>> delete connection, get connection list, get connection info. Adding
>> connection if it's possible (establishing network device connection) is
>> equivalent to starting bnep session. Bnep session handles data queue of
>> transmit, receive messages over bnep channel. It means that if we add
>> connection the received/transmitted data will be parsed immediately. In
>> case of get bnep features we want to know before session start, if we
>> should leave setup data on socket queue and let kernel to handle with it,
>> or in case of no setup handling support, if we should pull this message
>> and handle setup response within user space.
>>
>> Signed-off-by: Grzegorz Kolodziejczyk <grzegorz.kolodziejczyk@tieto.com>
>> ---
>> fs/compat_ioctl.c         | 1 +
>> net/bluetooth/bnep/bnep.h | 1 +
>> net/bluetooth/bnep/sock.c | 8 ++++++++
>> 3 files changed, 10 insertions(+)
>>
>> diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
>> index afec645..19fb0c8 100644
>> --- a/fs/compat_ioctl.c
>> +++ b/fs/compat_ioctl.c
>> @@ -570,6 +570,7 @@ static int mt_ioctl_trans(unsigned int fd, unsigned int cmd, void __user *argp)
>> #define BNEPCONNDEL   _IOW('B', 201, int)
>> #define BNEPGETCONNLIST       _IOR('B', 210, int)
>> #define BNEPGETCONNINFO       _IOR('B', 211, int)
>> +#define BNEPGETSUPPFEAT      _IOR('B', 212, int)
>>
>> #define CMTPCONNADD   _IOW('C', 200, int)
>> #define CMTPCONNDEL   _IOW('C', 201, int)
>> diff --git a/net/bluetooth/bnep/bnep.h b/net/bluetooth/bnep/bnep.h
>> index 5a5b16f..8709733 100644
>> --- a/net/bluetooth/bnep/bnep.h
>> +++ b/net/bluetooth/bnep/bnep.h
>> @@ -111,6 +111,7 @@ struct bnep_ext_hdr {
>> #define BNEPCONNDEL   _IOW('B', 201, int)
>> #define BNEPGETCONNLIST       _IOR('B', 210, int)
>> #define BNEPGETCONNINFO       _IOR('B', 211, int)
>> +#define BNEPGETSUPPFEAT      _IOR('B', 212, int)
>>
>> struct bnep_connadd_req {
>>       int   sock;             /* Connected socket */
>> diff --git a/net/bluetooth/bnep/sock.c b/net/bluetooth/bnep/sock.c
>> index 5f05129..f18b6bd 100644
>> --- a/net/bluetooth/bnep/sock.c
>> +++ b/net/bluetooth/bnep/sock.c
>> @@ -58,6 +58,8 @@ static int bnep_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long
>>       struct socket *nsock;
>>       void __user *argp = (void __user *)arg;
>>       int err;
>> +     const __u32 supp_feat = 0;
>
> I doubt that const is needed here. It is on the stack anyway. And personally I prefer it before the int err.
>
Ok.
>> +
>
> This extra empty line is against any coding style. Please be careful with these.
>
I've missed it, thanks.
>>       BT_DBG("cmd %x arg %lx", cmd, arg);
>>
>> @@ -120,6 +122,12 @@ static int bnep_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long
>>
>>               return err;
>>
>> +     case BNEPGETSUPPFEAT:
>> +             if (copy_to_user(argp, &supp_feat, sizeof(supp_feat)))
>> +                     return -EFAULT;
>> +
>> +             return 0;
>> +
>>       default:
>>               return -EINVAL;
>>       }
>
> Regards
>
> Marcel
>

Regards,
Grzegorz