Re: [PATCH 1/2] Bluetooth: notify userspace of security level change

[Marcel Holtmann <marcel@holtmann.org>]

Hi Gustavo,

> When the userspace request a security level change it needs to be notified
> of when the change is complete.
> This patch make the socket non writable while the security request is
> ongoing. If it succeeds POLL_OUT is emitted, otherwise the channel is
> disconnected.
> 
> Signed-off-by: Gustavo Padovan <gustavo@padovan.org>
> ---
>  include/net/bluetooth/bluetooth.h |    1 +
>  net/bluetooth/af_bluetooth.c      |    2 +-
>  net/bluetooth/hci_event.c         |    7 +++++++
>  net/bluetooth/l2cap_core.c        |    5 +++++
>  net/bluetooth/l2cap_sock.c        |   10 +++++-----
>  5 files changed, 19 insertions(+), 6 deletions(-)
> 
> diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
> index 2fb268f..4e750df 100644
> --- a/include/net/bluetooth/bluetooth.h
> +++ b/include/net/bluetooth/bluetooth.h
> @@ -195,6 +195,7 @@ struct bt_sock {
>  	struct list_head accept_q;
>  	struct sock *parent;
>  	u32 defer_setup;
> +	bool  suspended;

you have double spaces here. Please pay attention.

>  };
>  
>  struct bt_sock_list {
> diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
> index 72eb187..6fb68a9 100644
> --- a/net/bluetooth/af_bluetooth.c
> +++ b/net/bluetooth/af_bluetooth.c
> @@ -450,7 +450,7 @@ unsigned int bt_sock_poll(struct file *file, struct socket *sock, poll_table *wa
>  			sk->sk_state == BT_CONFIG)
>  		return mask;
>  
> -	if (sock_writeable(sk))
> +	if (!bt_sk(sk)->suspended && sock_writeable(sk))
>  		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
>  	else
>  		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 507fcec..86f74f6 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -2062,6 +2062,12 @@ static inline void hci_encrypt_change_evt(struct hci_dev *hdev, struct sk_buff *
>  
>  		clear_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags);
>  
> +		if (ev->status && conn->state == BT_CONNECTED) {
> +			hci_acl_disconn(conn, 0x13);
> +			hci_conn_put(conn);
> +			goto unlock;
> +		}
> +
>  		if (conn->state == BT_CONFIG) {
>  			if (!ev->status)
>  				conn->state = BT_CONNECTED;
> @@ -2072,6 +2078,7 @@ static inline void hci_encrypt_change_evt(struct hci_dev *hdev, struct sk_buff *
>  			hci_encrypt_cfm(conn, ev->status, ev->encrypt);
>  	}
>  
> +unlock:
>  	hci_dev_unlock(hdev);
>  }
>  
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index 0f2b1be..67053f8 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -4884,6 +4884,11 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
>  
>  		if (!status && (chan->state == BT_CONNECTED ||
>  						chan->state == BT_CONFIG)) {

You do know that this one will be showing up in Dave's coding style
complaint. You might wanna fix this with a pre-patch first.

> +			struct sock *sk = chan->sk;
> +
> +			bt_sk(sk)->suspended = false;
> +			sk->sk_state_change(sk);
> +
>  			l2cap_check_encryption(chan, encrypt);
>  			l2cap_chan_unlock(chan);
>  			continue;
> diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
> index 82b6368..7e3386f 100644
> --- a/net/bluetooth/l2cap_sock.c
> +++ b/net/bluetooth/l2cap_sock.c
> @@ -596,12 +596,12 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, ch
>  			sk->sk_state = BT_CONFIG;
>  			chan->state = BT_CONFIG;
>  
> -		/* or for ACL link, under defer_setup time */
> -		} else if (sk->sk_state == BT_CONNECT2 &&
> -					bt_sk(sk)->defer_setup) {
> -			err = l2cap_chan_check_security(chan);
> +		/* or for ACL link */
>  		} else {
> -			err = -EINVAL;
> +			if (!l2cap_chan_check_security(chan))
> +				bt_sk(sk)->suspended = true;
> +			else
> +				sk->sk_state_change(sk);
>  		}
>  		break;

Why is this change correct? You are changing this from applying to only
incoming connections (CONNECT2) to also outgoing connections (CONNECT).

Regards

Marcel