[PATCH v3 0/9] Bluetooth: L2CAP updates for PSM validation and ERTM

[PATCH v3 0/9] Bluetooth: L2CAP updates for PSM validation and ERTM

[Mat Martineau]

This is a collection of ERTM-related patches, including some L2CAP
configuration fixes and allowing partial-frame reads from L2CAP
SOCK_STREAM sockets.  PSM validation is also included, although that
is not restricted to ERTM.

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

[PATCH 1/9] Bluetooth: Only enable for L2CAP FCS for ERTM or streaming.

[Mat Martineau]

This fixes a bug which caused the FCS setting to show L2CAP_FCS_CRC16
with L2CAP modes other than ERTM or streaming.  At present, this only
affects the FCS value shown with getsockopt() for basic mode.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
---
 net/bluetooth/l2cap.c |   16 ++++++++++++----
 1 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 3e3cd9d..bc10be8 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -3072,6 +3072,16 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
 	return 0;
 }
 
+static inline int l2cap_fcs_needed(struct l2cap_pinfo *pi)
+{
+	if (pi->mode != L2CAP_MODE_ERTM && pi->mode != L2CAP_MODE_STREAMING)
+		return 0;
+
+	/* FCS is enabled if one or both sides request it. */
+	return !(pi->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
+		pi->fcs == L2CAP_FCS_CRC16;
+}
+
 static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data)
 {
 	struct l2cap_conf_req *req = (struct l2cap_conf_req *) data;
@@ -3136,8 +3146,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 		goto unlock;
 
 	if (l2cap_pi(sk)->conf_state & L2CAP_CONF_INPUT_DONE) {
-		if (!(l2cap_pi(sk)->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
-		    l2cap_pi(sk)->fcs != L2CAP_FCS_NONE)
+		if (l2cap_fcs_needed(l2cap_pi(sk)))
 			l2cap_pi(sk)->fcs = L2CAP_FCS_CRC16;
 
 		sk->sk_state = BT_CONNECTED;
@@ -3226,8 +3235,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	l2cap_pi(sk)->conf_state |= L2CAP_CONF_INPUT_DONE;
 
 	if (l2cap_pi(sk)->conf_state & L2CAP_CONF_OUTPUT_DONE) {
-		if (!(l2cap_pi(sk)->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
-		    l2cap_pi(sk)->fcs != L2CAP_FCS_NONE)
+		if (l2cap_fcs_needed(l2cap_pi(sk)))
 			l2cap_pi(sk)->fcs = L2CAP_FCS_CRC16;
 
 		sk->sk_state = BT_CONNECTED;
-- 
1.7.1

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

Re: [PATCH 1/9] Bluetooth: Only enable for L2CAP FCS for ERTM or streaming.

[Marcel Holtmann]

Hi Mat,

> This fixes a bug which caused the FCS setting to show L2CAP_FCS_CRC16
> with L2CAP modes other than ERTM or streaming.  At present, this only
> affects the FCS value shown with getsockopt() for basic mode.
> 
> Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
> ---
>  net/bluetooth/l2cap.c |   16 ++++++++++++----
>  1 files changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
> index 3e3cd9d..bc10be8 100644
> --- a/net/bluetooth/l2cap.c
> +++ b/net/bluetooth/l2cap.c
> @@ -3072,6 +3072,16 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
>  	return 0;
>  }
>  
> +static inline int l2cap_fcs_needed(struct l2cap_pinfo *pi)
> +{
> +	if (pi->mode != L2CAP_MODE_ERTM && pi->mode != L2CAP_MODE_STREAMING)
> +		return 0;
> +
> +	/* FCS is enabled if one or both sides request it. */
> +	return !(pi->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
> +		pi->fcs == L2CAP_FCS_CRC16;
> +}

so I think a switch statement is easier to read:

	switch (pi->mode) {
	case L2CAP_MODE_ERTM:
	case L2CAP_MODE_STREAMING:
		return !(pi->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
					pi->fcs == L2CAP_FCS_CRC16;
	}

	return 0;

>  static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data)
>  {
>  	struct l2cap_conf_req *req = (struct l2cap_conf_req *) data;
> @@ -3136,8 +3146,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
>  		goto unlock;
>  
>  	if (l2cap_pi(sk)->conf_state & L2CAP_CONF_INPUT_DONE) {
> -		if (!(l2cap_pi(sk)->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
> -		    l2cap_pi(sk)->fcs != L2CAP_FCS_NONE)
> +		if (l2cap_fcs_needed(l2cap_pi(sk)))
>  			l2cap_pi(sk)->fcs = L2CAP_FCS_CRC16;

While this is just fine, I think we might should make this a lot
simpler:

	if (l2cap_pi(sk)->conf_state & L2CAP_CONF_INPUT_DONE) {
		set_default_fcs(pi);

		...
	}

With then set_default_fcs() doing all the checks etc. and setting either
FCS_NONE or FCS_CRC16.

Would this work or do we have to deal with some funny default behavior?

Regards

Marcel

Re: [PATCH 1/9] Bluetooth: Only enable for L2CAP FCS for ERTM or streaming.

[Gustavo F. Padovan]

Hi Marcel,

* Marcel Holtmann <marcel@holtmann.org> [2010-08-08 22:43:00 -0400]:

> Hi Mat,
> 
> > This fixes a bug which caused the FCS setting to show L2CAP_FCS_CRC16
> > with L2CAP modes other than ERTM or streaming.  At present, this only
> > affects the FCS value shown with getsockopt() for basic mode.
> > 
> > Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
> > ---
> >  net/bluetooth/l2cap.c |   16 ++++++++++++----
> >  1 files changed, 12 insertions(+), 4 deletions(-)
> > 
> > diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
> > index 3e3cd9d..bc10be8 100644
> > --- a/net/bluetooth/l2cap.c
> > +++ b/net/bluetooth/l2cap.c
> > @@ -3072,6 +3072,16 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
> >  	return 0;
> >  }
> >  
> > +static inline int l2cap_fcs_needed(struct l2cap_pinfo *pi)
> > +{
> > +	if (pi->mode != L2CAP_MODE_ERTM && pi->mode != L2CAP_MODE_STREAMING)
> > +		return 0;
> > +
> > +	/* FCS is enabled if one or both sides request it. */
> > +	return !(pi->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
> > +		pi->fcs == L2CAP_FCS_CRC16;
> > +}
> 
> so I think a switch statement is easier to read:
> 
> 	switch (pi->mode) {
> 	case L2CAP_MODE_ERTM:
> 	case L2CAP_MODE_STREAMING:
> 		return !(pi->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
> 					pi->fcs == L2CAP_FCS_CRC16;
> 	}
> 
> 	return 0;
> 
> >  static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data)
> >  {
> >  	struct l2cap_conf_req *req = (struct l2cap_conf_req *) data;
> > @@ -3136,8 +3146,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
> >  		goto unlock;
> >  
> >  	if (l2cap_pi(sk)->conf_state & L2CAP_CONF_INPUT_DONE) {
> > -		if (!(l2cap_pi(sk)->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
> > -		    l2cap_pi(sk)->fcs != L2CAP_FCS_NONE)
> > +		if (l2cap_fcs_needed(l2cap_pi(sk)))
> >  			l2cap_pi(sk)->fcs = L2CAP_FCS_CRC16;
> 
> While this is just fine, I think we might should make this a lot
> simpler:
> 
> 	if (l2cap_pi(sk)->conf_state & L2CAP_CONF_INPUT_DONE) {
> 		set_default_fcs(pi);
> 
> 		...
> 	}
> 
> With then set_default_fcs() doing all the checks etc. and setting either
> FCS_NONE or FCS_CRC16.
> 
> Would this work or do we have to deal with some funny default behavior?

That will work. ;)

-- 
Gustavo F. Padovan
http://padovan.org

Re: [PATCH 1/9] Bluetooth: Only enable for L2CAP FCS for ERTM or streaming.

[Mat Martineau]

On Mon, 9 Aug 2010, Gustavo F. Padovan wrote:

> Hi Marcel,
>
> * Marcel Holtmann <marcel@holtmann.org> [2010-08-08 22:43:00 -0400]:
>
>> Hi Mat,
>>
>>> This fixes a bug which caused the FCS setting to show L2CAP_FCS_CRC16
>>> with L2CAP modes other than ERTM or streaming.  At present, this only
>>> affects the FCS value shown with getsockopt() for basic mode.
>>>
>>> Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
>>> ---
>>>  net/bluetooth/l2cap.c |   16 ++++++++++++----
>>>  1 files changed, 12 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
>>> index 3e3cd9d..bc10be8 100644
>>> --- a/net/bluetooth/l2cap.c
>>> +++ b/net/bluetooth/l2cap.c
>>> @@ -3072,6 +3072,16 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
>>>  	return 0;
>>>  }
>>>
>>> +static inline int l2cap_fcs_needed(struct l2cap_pinfo *pi)
>>> +{
>>> +	if (pi->mode != L2CAP_MODE_ERTM && pi->mode != L2CAP_MODE_STREAMING)
>>> +		return 0;
>>> +
>>> +	/* FCS is enabled if one or both sides request it. */
>>> +	return !(pi->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
>>> +		pi->fcs == L2CAP_FCS_CRC16;
>>> +}
>>
>> so I think a switch statement is easier to read:
>>
>> 	switch (pi->mode) {
>> 	case L2CAP_MODE_ERTM:
>> 	case L2CAP_MODE_STREAMING:
>> 		return !(pi->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
>> 					pi->fcs == L2CAP_FCS_CRC16;
>> 	}
>>
>> 	return 0;
>>
>>>  static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data)
>>>  {
>>>  	struct l2cap_conf_req *req = (struct l2cap_conf_req *) data;
>>> @@ -3136,8 +3146,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
>>>  		goto unlock;
>>>
>>>  	if (l2cap_pi(sk)->conf_state & L2CAP_CONF_INPUT_DONE) {
>>> -		if (!(l2cap_pi(sk)->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
>>> -		    l2cap_pi(sk)->fcs != L2CAP_FCS_NONE)
>>> +		if (l2cap_fcs_needed(l2cap_pi(sk)))
>>>  			l2cap_pi(sk)->fcs = L2CAP_FCS_CRC16;
>>
>> While this is just fine, I think we might should make this a lot
>> simpler:
>>
>> 	if (l2cap_pi(sk)->conf_state & L2CAP_CONF_INPUT_DONE) {
>> 		set_default_fcs(pi);
>>
>> 		...
>> 	}
>>
>> With then set_default_fcs() doing all the checks etc. and setting either
>> FCS_NONE or FCS_CRC16.
>>
>> Would this work or do we have to deal with some funny default behavior?
>
> That will work. ;)

Agreed - that's much more readable.

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

[PATCH 2/9] Bluetooth: Change default ERTM retransmit timeout.

[Mat Martineau]

The L2CAP spec requires that the ERTM retransmit timeout be at least 2
seconds for BR/EDR connections.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
---
 include/net/bluetooth/l2cap.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 636724b..16e412f 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -33,7 +33,7 @@
 #define L2CAP_DEFAULT_FLUSH_TO		0xffff
 #define L2CAP_DEFAULT_TX_WINDOW		63
 #define L2CAP_DEFAULT_MAX_TX		3
-#define L2CAP_DEFAULT_RETRANS_TO	1000    /* 1 second */
+#define L2CAP_DEFAULT_RETRANS_TO	2000    /* 2 seconds */
 #define L2CAP_DEFAULT_MONITOR_TO	12000   /* 12 seconds */
 #define L2CAP_DEFAULT_MAX_PDU_SIZE	672
 #define L2CAP_DEFAULT_ACK_TO		200
-- 
1.7.1

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

Re: [PATCH 2/9] Bluetooth: Change default ERTM retransmit timeout.

[Marcel Holtmann]

Hi Mat,

> The L2CAP spec requires that the ERTM retransmit timeout be at least 2
> seconds for BR/EDR connections.
> 
> Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
> ---
>  include/net/bluetooth/l2cap.h |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)

patch has been applied. Thanks.

Regards

Marcel

[PATCH 3/9] Bluetooth: Validate PSM values in calls to connect() and bind().

[Mat Martineau]

Valid L2CAP PSMs are odd numbers, and the least significant bit of the
most significant byte must be 0.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
---
 net/bluetooth/l2cap.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index bc10be8..77ba106 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1008,6 +1008,12 @@ static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
 		goto done;
 	}
 
+	/* If specified, PSM must be odd and lsb of upper byte must be 0 */
+	if (la.l2_psm && (__le16_to_cpu(la.l2_psm) & 0x0101) != 0x0001) {
+		err = -EINVAL;
+		goto done;
+	}
+
 	if (la.l2_psm && __le16_to_cpu(la.l2_psm) < 0x1001 &&
 				!capable(CAP_NET_BIND_SERVICE)) {
 		err = -EACCES;
@@ -1190,6 +1196,12 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, int al
 		goto done;
 	}
 
+	/* PSM must be odd and lsb of upper byte must be 0 */
+	if ((__le16_to_cpu(la.l2_psm) & 0x0101) != 0x0001) {
+		err = -EINVAL;
+		goto done;
+	}
+
 	/* Set destination address and psm */
 	bacpy(&bt_sk(sk)->dst, &la.l2_bdaddr);
 	l2cap_pi(sk)->psm = la.l2_psm;
-- 
1.7.1

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

Re: [PATCH 3/9] Bluetooth: Validate PSM values in calls to connect() and bind().

[Marcel Holtmann]

Hi Mat,

> Valid L2CAP PSMs are odd numbers, and the least significant bit of the
> most significant byte must be 0.
> 
> Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
> ---
>  net/bluetooth/l2cap.c |   12 ++++++++++++
>  1 files changed, 12 insertions(+), 0 deletions(-)
> 
> diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
> index bc10be8..77ba106 100644
> --- a/net/bluetooth/l2cap.c
> +++ b/net/bluetooth/l2cap.c
> @@ -1008,6 +1008,12 @@ static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
>  		goto done;
>  	}
>  
> +	/* If specified, PSM must be odd and lsb of upper byte must be 0 */
> +	if (la.l2_psm && (__le16_to_cpu(la.l2_psm) & 0x0101) != 0x0001) {
> +		err = -EINVAL;
> +		goto done;
> +	}
> +
>  	if (la.l2_psm && __le16_to_cpu(la.l2_psm) < 0x1001 &&
>  				!capable(CAP_NET_BIND_SERVICE)) {
>  		err = -EACCES;

we might wanna do this a bit nicer here:

	if (la.l2_psm) {
		__u16 psm = __le16_to_cpu(la.l2_psm);

		if ((psm & 0x0101) != 0x0001) {
			err = -EINVAL;
			goto done;
		}

		if (psm < 0x1001 && ...) {
			...
		}
	}

Regards

Marcel

[PATCH 4/9] Bluetooth: Fix endianness issue with L2CAP MPS configuration.

[Mat Martineau]

Incoming configuration values must be converted to native CPU order
before use.  This fixes a bug where a little-endian MPS value is
compared to a native CPU value.  On big-endian processors, this
can cause ERTM and streaming mode segmentation to produce PDUs
that are larger than the remote stack is expecting, or that would
produce fragmented skbs that the current FCS code cannot handle.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
---
 net/bluetooth/l2cap.c |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 77ba106..5541b56 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -2717,8 +2717,9 @@ done:
 		case L2CAP_MODE_ERTM:
 			pi->remote_tx_win = rfc.txwin_size;
 			pi->remote_max_tx = rfc.max_transmit;
-			if (rfc.max_pdu_size > pi->conn->mtu - 10)
-				rfc.max_pdu_size = le16_to_cpu(pi->conn->mtu - 10);
+
+			if (le16_to_cpu(rfc.max_pdu_size) > pi->conn->mtu - 10)
+				rfc.max_pdu_size = cpu_to_le16(pi->conn->mtu - 10);
 
 			pi->remote_mps = le16_to_cpu(rfc.max_pdu_size);
 
@@ -2735,8 +2736,8 @@ done:
 			break;
 
 		case L2CAP_MODE_STREAMING:
-			if (rfc.max_pdu_size > pi->conn->mtu - 10)
-				rfc.max_pdu_size = le16_to_cpu(pi->conn->mtu - 10);
+			if (le16_to_cpu(rfc.max_pdu_size) > pi->conn->mtu - 10)
+				rfc.max_pdu_size = cpu_to_le16(pi->conn->mtu - 10);
 
 			pi->remote_mps = le16_to_cpu(rfc.max_pdu_size);
 
-- 
1.7.1

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

Re: [PATCH 4/9] Bluetooth: Fix endianness issue with L2CAP MPS configuration.

[Marcel Holtmann]

Hi Mat,

> Incoming configuration values must be converted to native CPU order
> before use.  This fixes a bug where a little-endian MPS value is
> compared to a native CPU value.  On big-endian processors, this
> can cause ERTM and streaming mode segmentation to produce PDUs
> that are larger than the remote stack is expecting, or that would
> produce fragmented skbs that the current FCS code cannot handle.
> 
> Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
> ---
>  net/bluetooth/l2cap.c |    9 +++++----
>  1 files changed, 5 insertions(+), 4 deletions(-)

patch has been applied. Thanks.

Regards

Marcel

[PATCH 5/9] Bluetooth: Fix incorrect setting of remote_tx_win for L2CAP ERTM.

[Mat Martineau]

remote_tx_win is intended to be set on receipt of an L2CAP
configuration request.  The value is used to determine the size of the
transmit window on the remote side of an ERTM connection, so L2CAP
can stop sending frames when that remote window is full.

An incorrect remote_tx_win value will cause the stack to not fully
utilize the tx window (performance impact), or to overfill the remote
tx window (causing dropped frames or a disconnect).

This patch removes an extra setting of remote_tx_win when a
configuration response is received.  The transmit window has a
different meaning in a response - it is an informational value
less than or equal to the local tx_win.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
---
 net/bluetooth/l2cap.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 5541b56..43e0eae 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -2819,7 +2819,6 @@ static int l2cap_parse_conf_rsp(struct sock *sk, void *rsp, int len, void *data,
 	if (*result == L2CAP_CONF_SUCCESS) {
 		switch (rfc.mode) {
 		case L2CAP_MODE_ERTM:
-			pi->remote_tx_win   = rfc.txwin_size;
 			pi->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
 			pi->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
 			pi->mps    = le16_to_cpu(rfc.max_pdu_size);
@@ -2875,7 +2874,6 @@ static void l2cap_conf_rfc_get(struct sock *sk, void *rsp, int len)
 done:
 	switch (rfc.mode) {
 	case L2CAP_MODE_ERTM:
-		pi->remote_tx_win   = rfc.txwin_size;
 		pi->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
 		pi->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
 		pi->mps    = le16_to_cpu(rfc.max_pdu_size);
-- 
1.7.1

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

Re: [PATCH 5/9] Bluetooth: Fix incorrect setting of remote_tx_win for L2CAP ERTM.

[Marcel Holtmann]

Hi Mat,

> remote_tx_win is intended to be set on receipt of an L2CAP
> configuration request.  The value is used to determine the size of the
> transmit window on the remote side of an ERTM connection, so L2CAP
> can stop sending frames when that remote window is full.
> 
> An incorrect remote_tx_win value will cause the stack to not fully
> utilize the tx window (performance impact), or to overfill the remote
> tx window (causing dropped frames or a disconnect).
> 
> This patch removes an extra setting of remote_tx_win when a
> configuration response is received.  The transmit window has a
> different meaning in a response - it is an informational value
> less than or equal to the local tx_win.
> 
> Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
> ---
>  net/bluetooth/l2cap.c |    2 --
>  1 files changed, 0 insertions(+), 2 deletions(-)

patch has been applied. Thanks.

Regards

Marcel

[PATCH 6/9] Bluetooth: Add common code for stream-oriented recvmsg()

[Mat Martineau]

This commit adds a bt_sock_stream_recvmsg() function for use by any
Bluetooth code that uses SOCK_STREAM sockets.  This code is copied
from rfcomm_sock_recvmsg() with minimal modifications to remove
RFCOMM-specific functionality and improve readability.

L2CAP (with the SOCK_STREAM socket type) and RFCOMM have common needs
when it comes to reading data.  Proper stream read semantics require
that applications can read from a stream one byte at a time and not
lose any data.  The RFCOMM code already operated on and pulled data
from the underlying L2CAP socket, so very few changes were required to
make the code more generic for use with non-RFCOMM data over L2CAP.

Applications that need more awareness of L2CAP frame boundaries are
still free to use SOCK_SEQPACKET sockets, and may verify that they
connection did not fall back to basic mode by calling getsockopt().

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
---
 include/net/bluetooth/bluetooth.h |    2 +
 net/bluetooth/af_bluetooth.c      |  109 +++++++++++++++++++++++++++++++++++++
 2 files changed, 111 insertions(+), 0 deletions(-)

diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
index 27a902d..08b6c2a 100644
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -126,6 +126,8 @@ int  bt_sock_unregister(int proto);
 void bt_sock_link(struct bt_sock_list *l, struct sock *s);
 void bt_sock_unlink(struct bt_sock_list *l, struct sock *s);
 int  bt_sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len, int flags);
+int  bt_sock_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
+			struct msghdr *msg, size_t len, int flags);
 uint bt_sock_poll(struct file * file, struct socket *sock, poll_table *wait);
 int  bt_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
 int  bt_sock_wait_state(struct sock *sk, int state, unsigned long timeo);
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index 421c45b..77a26fe 100644
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -265,6 +265,115 @@ int bt_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 }
 EXPORT_SYMBOL(bt_sock_recvmsg);
 
+static long bt_sock_data_wait(struct sock *sk, long timeo)
+{
+	DECLARE_WAITQUEUE(wait, current);
+
+	add_wait_queue(sk_sleep(sk), &wait);
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		if (!skb_queue_empty(&sk->sk_receive_queue))
+			break;
+
+		if (sk->sk_err || (sk->sk_shutdown & RCV_SHUTDOWN))
+			break;
+
+		if (signal_pending(current) || !timeo)
+			break;
+
+		set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
+		release_sock(sk);
+		timeo = schedule_timeout(timeo);
+		lock_sock(sk);
+		clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
+	}
+
+	__set_current_state(TASK_RUNNING);
+	remove_wait_queue(sk_sleep(sk), &wait);
+	return timeo;
+}
+
+int bt_sock_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
+			       struct msghdr *msg, size_t size, int flags)
+{
+	struct sock *sk = sock->sk;
+	int err = 0;
+	size_t target, copied = 0;
+	long timeo;
+
+	if (flags & MSG_OOB)
+		return -EOPNOTSUPP;
+
+	msg->msg_namelen = 0;
+
+	BT_DBG("sk %p size %zu", sk, size);
+
+	lock_sock(sk);
+
+	target = sock_rcvlowat(sk, flags & MSG_WAITALL, size);
+	timeo  = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
+
+	do {
+		struct sk_buff *skb;
+		int chunk;
+
+		skb = skb_dequeue(&sk->sk_receive_queue);
+		if (!skb) {
+			if (copied >= target)
+				break;
+
+			if ((err = sock_error(sk)) != 0)
+				break;
+			if (sk->sk_shutdown & RCV_SHUTDOWN)
+				break;
+
+			err = -EAGAIN;
+			if (!timeo)
+				break;
+
+			timeo = bt_sock_data_wait(sk, timeo);
+
+			if (signal_pending(current)) {
+				err = sock_intr_errno(timeo);
+				goto out;
+			}
+			continue;
+		}
+
+		chunk = min_t(unsigned int, skb->len, size);
+		if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
+			skb_queue_head(&sk->sk_receive_queue, skb);
+			if (!copied)
+				copied = -EFAULT;
+			break;
+		}
+		copied += chunk;
+		size   -= chunk;
+
+		sock_recv_ts_and_drops(msg, sk, skb);
+
+		if (!(flags & MSG_PEEK)) {
+			skb_pull(skb, chunk);
+			if (skb->len) {
+				skb_queue_head(&sk->sk_receive_queue, skb);
+				break;
+			}
+			kfree_skb(skb);
+
+		} else {
+			/* put message back and return */
+			skb_queue_head(&sk->sk_receive_queue, skb);
+			break;
+		}
+	} while (size);
+
+out:
+	release_sock(sk);
+	return copied ? : err;
+}
+EXPORT_SYMBOL(bt_sock_stream_recvmsg);
+
 static inline unsigned int bt_accept_poll(struct sock *parent)
 {
 	struct list_head *p, *n;
-- 
1.7.1

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

[PATCH 7/9] Bluetooth: Use common SOCK_STREAM receive code in RFCOMM.

[Mat Martineau]

To reduce code duplication, have rfcomm_sock_recvmsg() call
bt_sock_stream_recvmsg().  The common bt_sock_stream_recvmsg()
code is nearly identical, with the RFCOMM-specific functionality
for deferred setup and connection unthrottling left in
rfcomm_sock_recvmsg().

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
---
 net/bluetooth/rfcomm/sock.c |  104 +++----------------------------------------
 1 files changed, 6 insertions(+), 98 deletions(-)

diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 44a6232..4396f47 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -617,121 +617,29 @@ static int rfcomm_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
 	return sent;
 }
 
-static long rfcomm_sock_data_wait(struct sock *sk, long timeo)
-{
-	DECLARE_WAITQUEUE(wait, current);
-
-	add_wait_queue(sk_sleep(sk), &wait);
-	for (;;) {
-		set_current_state(TASK_INTERRUPTIBLE);
-
-		if (!skb_queue_empty(&sk->sk_receive_queue) ||
-		    sk->sk_err ||
-		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
-		    signal_pending(current) ||
-		    !timeo)
-			break;
-
-		set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
-		release_sock(sk);
-		timeo = schedule_timeout(timeo);
-		lock_sock(sk);
-		clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
-	}
-
-	__set_current_state(TASK_RUNNING);
-	remove_wait_queue(sk_sleep(sk), &wait);
-	return timeo;
-}
-
 static int rfcomm_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 			       struct msghdr *msg, size_t size, int flags)
 {
 	struct sock *sk = sock->sk;
 	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
-	int err = 0;
-	size_t target, copied = 0;
-	long timeo;
+	int len;
 
 	if (test_and_clear_bit(RFCOMM_DEFER_SETUP, &d->flags)) {
 		rfcomm_dlc_accept(d);
 		return 0;
 	}
 
-	if (flags & MSG_OOB)
-		return -EOPNOTSUPP;
-
-	msg->msg_namelen = 0;
-
-	BT_DBG("sk %p size %zu", sk, size);
+	len = bt_sock_stream_recvmsg(iocb, sock, msg, size, flags);
 
 	lock_sock(sk);
+	if (!(flags & MSG_PEEK) && len > 0)
+		atomic_sub(len, &sk->sk_rmem_alloc);
 
-	target = sock_rcvlowat(sk, flags & MSG_WAITALL, size);
-	timeo  = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
-
-	do {
-		struct sk_buff *skb;
-		int chunk;
-
-		skb = skb_dequeue(&sk->sk_receive_queue);
-		if (!skb) {
-			if (copied >= target)
-				break;
-
-			if ((err = sock_error(sk)) != 0)
-				break;
-			if (sk->sk_shutdown & RCV_SHUTDOWN)
-				break;
-
-			err = -EAGAIN;
-			if (!timeo)
-				break;
-
-			timeo = rfcomm_sock_data_wait(sk, timeo);
-
-			if (signal_pending(current)) {
-				err = sock_intr_errno(timeo);
-				goto out;
-			}
-			continue;
-		}
-
-		chunk = min_t(unsigned int, skb->len, size);
-		if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
-			skb_queue_head(&sk->sk_receive_queue, skb);
-			if (!copied)
-				copied = -EFAULT;
-			break;
-		}
-		copied += chunk;
-		size   -= chunk;
-
-		sock_recv_ts_and_drops(msg, sk, skb);
-
-		if (!(flags & MSG_PEEK)) {
-			atomic_sub(chunk, &sk->sk_rmem_alloc);
-
-			skb_pull(skb, chunk);
-			if (skb->len) {
-				skb_queue_head(&sk->sk_receive_queue, skb);
-				break;
-			}
-			kfree_skb(skb);
-
-		} else {
-			/* put message back and return */
-			skb_queue_head(&sk->sk_receive_queue, skb);
-			break;
-		}
-	} while (size);
-
-out:
 	if (atomic_read(&sk->sk_rmem_alloc) <= (sk->sk_rcvbuf >> 2))
 		rfcomm_dlc_unthrottle(rfcomm_pi(sk)->dlc);
-
 	release_sock(sk);
-	return copied ? : err;
+
+	return len;
 }
 
 static int rfcomm_sock_setsockopt_old(struct socket *sock, int optname, char __user *optval, unsigned int optlen)
-- 
1.7.1

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

[PATCH 8/9] Bluetooth: Use a stream-oriented recvmsg with SOCK_STREAM L2CAP sockets.

[Mat Martineau]

L2CAP ERTM sockets can be opened with the SOCK_STREAM socket type,
which is a mandatory request for ERTM mode.

However, these sockets still have SOCK_SEQPACKET read semantics when
bt_sock_recvmsg() is used to pull data from the receive queue.  If the
application is only reading part of a frame, then the unread portion
of the frame is discarded.  If the application requests more bytes
than are in the current frame, only the current frame's data is
returned.

This patch utilizes common code derived from RFCOMM's recvmsg()
function to make L2CAP SOCK_STREAM reads behave like RFCOMM reads (and
other SOCK_STREAM sockets in general).  The application may read one
byte at a time from the input stream and not lose any data, and may
also read across L2CAP frame boundaries.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
---
 net/bluetooth/l2cap.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 43e0eae..cd0e150 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1956,7 +1956,10 @@ static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct ms
 
 	release_sock(sk);
 
-	return bt_sock_recvmsg(iocb, sock, msg, len, flags);
+	if (sock->type == SOCK_STREAM)
+		return bt_sock_stream_recvmsg(iocb, sock, msg, len, flags);
+	else
+		return bt_sock_recvmsg(iocb, sock, msg, len, flags);
 }
 
 static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __user *optval, unsigned int optlen)
-- 
1.7.1

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

Re: [PATCH 8/9] Bluetooth: Use a stream-oriented recvmsg with SOCK_STREAM L2CAP sockets.

[Marcel Holtmann]

Hi Mat,

> L2CAP ERTM sockets can be opened with the SOCK_STREAM socket type,
> which is a mandatory request for ERTM mode.
> 
> However, these sockets still have SOCK_SEQPACKET read semantics when
> bt_sock_recvmsg() is used to pull data from the receive queue.  If the
> application is only reading part of a frame, then the unread portion
> of the frame is discarded.  If the application requests more bytes
> than are in the current frame, only the current frame's data is
> returned.
> 
> This patch utilizes common code derived from RFCOMM's recvmsg()
> function to make L2CAP SOCK_STREAM reads behave like RFCOMM reads (and
> other SOCK_STREAM sockets in general).  The application may read one
> byte at a time from the input stream and not lose any data, and may
> also read across L2CAP frame boundaries.
> 
> Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
> ---
>  net/bluetooth/l2cap.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
> index 43e0eae..cd0e150 100644
> --- a/net/bluetooth/l2cap.c
> +++ b/net/bluetooth/l2cap.c
> @@ -1956,7 +1956,10 @@ static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct ms
>  
>  	release_sock(sk);
>  
> -	return bt_sock_recvmsg(iocb, sock, msg, len, flags);
> +	if (sock->type == SOCK_STREAM)
> +		return bt_sock_stream_recvmsg(iocb, sock, msg, len, flags);
> +	else
> +		return bt_sock_recvmsg(iocb, sock, msg, len, flags);
>  }
>  
>  static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __user *optval, unsigned int optlen)

this is more a style issue, but I clearly prefer this:

	if (sock->type == SOCK_STREAM)
		return bt_sock_stream_recvmsg(iocb, sock, msg, len, flags);

	return bt_sock_recvmsg(iocb, sock, msg, len, flags);

Regards

Marcel

[PATCH 9/9] Bluetooth: Use 3-DH5 payload size for default ERTM max PDU size.

[Mat Martineau]

The previous value of 672 for L2CAP_DEFAULT_MAX_PDU_SIZE is based on
the default L2CAP MTU.  That default MTU is calculated from the size
of two DH5 packets, minus ACL and L2CAP b-frame header overhead.

ERTM is used with newer basebands that typically support larger 3-DH5
packets, and i-frames and s-frames have more header overhead.  With
clean RF conditions, basebands will typically attempt to use 1021-byte
3-DH5 packets for maximum throughput.  Adjusting for 2 bytes of ACL
headers plus 10 bytes of worst-case L2CAP headers yields 1009 bytes
of payload.

This PDU size imposes less overhead for header bytes and gives the
baseband the option to choose 3-DH5 packets, but is small enough for
ERTM traffic to interleave well with other L2CAP or SCO data.
672-byte payloads do not allow the most efficient over-the-air
packet choice, and cannot achieve maximum throughput over BR/EDR.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
---
 include/net/bluetooth/l2cap.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 16e412f..6c24144 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -35,7 +35,7 @@
 #define L2CAP_DEFAULT_MAX_TX		3
 #define L2CAP_DEFAULT_RETRANS_TO	2000    /* 2 seconds */
 #define L2CAP_DEFAULT_MONITOR_TO	12000   /* 12 seconds */
-#define L2CAP_DEFAULT_MAX_PDU_SIZE	672
+#define L2CAP_DEFAULT_MAX_PDU_SIZE	1009    /* Sized for 3-DH5 packet */
 #define L2CAP_DEFAULT_ACK_TO		200
 #define L2CAP_LOCAL_BUSY_TRIES		12
 
-- 
1.7.1

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

Re: [PATCH 9/9] Bluetooth: Use 3-DH5 payload size for default ERTM max PDU size.

[Marcel Holtmann]

Hi Mat,

> The previous value of 672 for L2CAP_DEFAULT_MAX_PDU_SIZE is based on
> the default L2CAP MTU.  That default MTU is calculated from the size
> of two DH5 packets, minus ACL and L2CAP b-frame header overhead.
> 
> ERTM is used with newer basebands that typically support larger 3-DH5
> packets, and i-frames and s-frames have more header overhead.  With
> clean RF conditions, basebands will typically attempt to use 1021-byte
> 3-DH5 packets for maximum throughput.  Adjusting for 2 bytes of ACL
> headers plus 10 bytes of worst-case L2CAP headers yields 1009 bytes
> of payload.
> 
> This PDU size imposes less overhead for header bytes and gives the
> baseband the option to choose 3-DH5 packets, but is small enough for
> ERTM traffic to interleave well with other L2CAP or SCO data.
> 672-byte payloads do not allow the most efficient over-the-air
> packet choice, and cannot achieve maximum throughput over BR/EDR.
> 
> Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
> ---
>  include/net/bluetooth/l2cap.h |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)

patch has been applied. Thanks.

Regards

Marcel

[PATCH v2 0/9] Bluetooth: L2CAP updates for PSM validation and ERTM.

[Mat Martineau]

This is a collection of ERTM-related patches, including some L2CAP
configuration fixes and allowing partial-frame reads from L2CAP
SOCK_STREAM sockets.  PSM validation is also included, although that
is not restricted to ERTM.

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

[PATCH 8/9] Bluetooth: Use a stream-oriented recvmsg with SOCK_STREAM L2CAP sockets.

[Mat Martineau]

L2CAP ERTM sockets can be opened with the SOCK_STREAM socket type,
which is a mandatory request for ERTM mode.

However, these sockets still have SOCK_SEQPACKET read semantics when
bt_sock_recvmsg() is used to pull data from the receive queue.  If the
application is only reading part of a frame, then the unread portion
of the frame is discarded.  If the application requests more bytes
than are in the current frame, only the current frame's data is
returned.

This patch utilizes common code derived from RFCOMM's recvmsg()
function to make L2CAP SOCK_STREAM reads behave like RFCOMM reads (and
other SOCK_STREAM sockets in general).  The application may read one
byte at a time from the input stream and not lose any data, and may
also read across L2CAP frame boundaries.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
---
 net/bluetooth/l2cap.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index f0f3c7c..b9de88d 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1956,7 +1956,10 @@ static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct ms
 
 	release_sock(sk);
 
-	return bt_sock_recvmsg(iocb, sock, msg, len, flags);
+	if (sock->type == SOCK_STREAM)
+		return bt_sock_stream_recvmsg(iocb, sock, msg, len, flags);
+	else
+		return bt_sock_recvmsg(iocb, sock, msg, len, flags);
 }
 
 static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __user *optval, unsigned int optlen)
-- 
1.7.1

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum