Re: [PATCH -v2 4/8] Bluetooth: Add chan->ops->defer()

Hi Marcel,

* Marcel Holtmann [off-list ref] [2012-10-11 15:49:23 +0200]:

Hi Gustavo,

quoted

When DEFER_SETUP is set defer() will trigger an authorization
request to the userspace.

Signed-off-by: Gustavo Padovan <redacted>
---
 include/net/bluetooth/l2cap.h |  5 +++++
 net/bluetooth/a2mp.c          |  1 +
 net/bluetooth/l2cap_core.c    | 10 +++-------
 net/bluetooth/l2cap_sock.c    | 13 +++++++++++++
 4 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index caab98c..6e23afd 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h

@@ -541,6 +541,7 @@ struct l2cap_ops {
 	void			(*state_change) (struct l2cap_chan *chan,
 						 int state);
 	void			(*ready) (struct l2cap_chan *chan);
+	void			(*defer) (struct l2cap_chan *chan);
 	struct sk_buff		*(*alloc_skb) (struct l2cap_chan *chan,
 					       unsigned long len, int nb);
 };

@@ -748,6 +749,10 @@ static inline void l2cap_chan_no_ready(struct l2cap_chan *chan)
 {
 }
 
+static inline void l2cap_chan_no_defer(struct l2cap_chan *chan)
+{
+}
+
 extern bool disable_ertm;
 
 int l2cap_init_sockets(void);

diff --git a/net/bluetooth/a2mp.c b/net/bluetooth/a2mp.c
index 3ff4dc9..7bf9a10 100644
--- a/net/bluetooth/a2mp.c
+++ b/net/bluetooth/a2mp.c

@@ -699,6 +699,7 @@ static struct l2cap_ops a2mp_chan_ops = {
 	.new_connection = l2cap_chan_no_new_connection,
 	.teardown = l2cap_chan_no_teardown,
 	.ready = l2cap_chan_no_ready,
+	.defer = l2cap_chan_no_defer,
 };
 
 static struct l2cap_chan *a2mp_chan_open(struct l2cap_conn *conn, bool locked)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 91d312b..a2f945d 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c

@@ -1123,11 +1123,9 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 				lock_sock(sk);
 				if (test_bit(BT_SK_DEFER_SETUP,
 					     &bt_sk(sk)->flags)) {
-					struct sock *parent = bt_sk(sk)->parent;
 					rsp.result = __constant_cpu_to_le16(L2CAP_CR_PEND);
 					rsp.status = __constant_cpu_to_le16(L2CAP_CS_AUTHOR_PEND);
-					if (parent)
-						parent->sk_data_ready(parent, 0);
+					chan->ops->defer(chan);

I would prefer you explain this in detail. Sine the no_defer is then no
longer calling sk_data_ready. Is this safe?

Yes, this is safe, the no_defer exists only to be used by those that do not
implement DEFER_SETUP support. Actually ops->defer() will never be called if
DEFER_SETUP is no enabled.

quoted

 
 				} else {
 					__l2cap_state_change(chan, BT_CONFIG);

@@ -3459,7 +3457,7 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn,
 				__l2cap_state_change(chan, BT_CONNECT2);
 				result = L2CAP_CR_PEND;
 				status = L2CAP_CS_AUTHOR_PEND;
-				parent->sk_data_ready(parent, 0);
+				chan->ops->defer(chan);
 			} else {
 				__l2cap_state_change(chan, BT_CONFIG);
 				result = L2CAP_CR_SUCCESS;

@@ -5520,11 +5518,9 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 			if (!status) {
 				if (test_bit(BT_SK_DEFER_SETUP,
 					     &bt_sk(sk)->flags)) {
-					struct sock *parent = bt_sk(sk)->parent;
 					res = L2CAP_CR_PEND;
 					stat = L2CAP_CS_AUTHOR_PEND;
-					if (parent)
-						parent->sk_data_ready(parent, 0);
+					chan->ops->defer(chan);
 				} else {
 					__l2cap_state_change(chan, BT_CONFIG);
 					res = L2CAP_CR_SUCCESS;

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 45c81e1..efcb914 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c

@@ -956,6 +956,7 @@ static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan)
 
 	bt_accept_enqueue(parent, sk);
 
+

No pointless empty lines please.

Yes, this is the leftover from a merge conflict. I'll remove it.

quoted

 	release_sock(parent);
 
 	return l2cap_pi(sk)->chan;

@@ -1088,6 +1089,17 @@ static void l2cap_sock_ready_cb(struct l2cap_chan *chan)
 	release_sock(sk);
 }
 
+static void l2cap_sock_defer_cb(struct l2cap_chan *chan)
+{
+	struct sock *sk = chan->data;
+	struct sock *parent;
+
+	parent = bt_sk(sk)->parent;

You can do struct sock *parent = bt_sk(sk)-parent here.

Sure.

quoted

+
+	if (parent)
+		parent->sk_data_ready(parent, 0);
+}
+
 static struct l2cap_ops l2cap_chan_ops = {
 	.name		= "L2CAP Socket Interface",
 	.new_connection	= l2cap_sock_new_connection_cb,

@@ -1096,6 +1108,7 @@ static struct l2cap_ops l2cap_chan_ops = {
 	.teardown	= l2cap_sock_teardown_cb,
 	.state_change	= l2cap_sock_state_change_cb,
 	.ready		= l2cap_sock_ready_cb,
+	.defer		= l2cap_sock_defer_cb,
 	.alloc_skb	= l2cap_sock_alloc_skb_cb,
 };
 

I am bit unease with accidentally having no_defer and then DEFER_SETUP
is set. Are we not changing behavior here?

No, as I said above, this case will not happen.

	Gustavo