[PATCH v2 0/4] sco: SCO socket option for mode

[PATCH v2 0/4] sco: SCO socket option for mode

[Frédéric Dalleau]

Hi,

This is the patch version 2 of the socket option for enabling transparent SCO
sockets. I kept the mode name.
The initial mode corresponding to current behavior is SCO_MODE_CVSD.
SCO_MODE_TRANSPARENT is the mode for setting up transparent data sockets.
Because it is still foggy, SCO_MODE_ENHANCED is no longer declared in this
series, it is sent as an additional RFC.

Let me know what you think.
Best regards,

Frédéric Dalleau (4):
  Bluetooth: Add option for SCO socket mode
  Bluetooth: Use mode to create SCO connection
  Bluetooth: Parameters for outgoing SCO connections
  Bluetooth: Fallback transparent SCO from T2 to T1

 include/net/bluetooth/hci_core.h |    5 ++-
 include/net/bluetooth/sco.h      |    7 +++++
 net/bluetooth/hci_conn.c         |   38 ++++++++++++++++------
 net/bluetooth/hci_event.c        |   22 ++++++++++---
 net/bluetooth/sco.c              |   64 ++++++++++++++++++++++++++++++++++++--
 5 files changed, 118 insertions(+), 18 deletions(-)

-- 
1.7.9.5

[PATCH v2 1/4] Bluetooth: Add option for SCO socket mode

[Frédéric Dalleau]

This patch extends the current SCO socket option to add a 'mode' field. This
field is intended to choose data type at runtime. Current modes are CVSD and
transparent SCO, but adding new modes could allow support for CSA2 and fine
tuning a sco connection, for example latency, bandwith, voice setting. Incoming
connections will be setup during defered setup. Outgoing connections have to
be setup before connect(). The selected type is stored in the sco socket info.
This patch declares needed members, modifies getsockopt() and implements
setsockopt(). Setting the mtu is not supported.

Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com>
---
 include/net/bluetooth/sco.h |    7 +++++
 net/bluetooth/sco.c         |   59 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/include/net/bluetooth/sco.h b/include/net/bluetooth/sco.h
index 1e35c43..c8c228f 100644
--- a/include/net/bluetooth/sco.h
+++ b/include/net/bluetooth/sco.h
@@ -41,8 +41,14 @@ struct sockaddr_sco {
 
 /* SCO socket options */
 #define SCO_OPTIONS	0x01
+
+#define SCO_MODE_CVSD		0x00
+#define SCO_MODE_TRANSPARENT	0x01
+#define SCO_MODE_MAX            0x02
+
 struct sco_options {
 	__u16 mtu;
+	__u8 mode;
 };
 
 #define SCO_CONNINFO	0x02
@@ -73,6 +79,7 @@ struct sco_conn {
 struct sco_pinfo {
 	struct bt_sock	bt;
 	__u32		flags;
+	__u8		mode;
 	struct sco_conn	*conn;
 };
 
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index 531a93d..927119e6 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -418,6 +418,8 @@ static struct sock *sco_sock_alloc(struct net *net, struct socket *sock, int pro
 	sk->sk_protocol = proto;
 	sk->sk_state    = BT_OPEN;
 
+	sco_pi(sk)->mode = SCO_MODE_CVSD;
+
 	setup_timer(&sk->sk_timer, sco_sock_timeout, (unsigned long)sk);
 
 	bt_sock_link(&sco_sk_list, sk);
@@ -676,6 +678,59 @@ static int sco_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 	return bt_sock_recvmsg(iocb, sock, msg, len, flags);
 }
 
+static int sco_sock_setsockopt_old(struct socket *sock, int optname,
+				   char __user *optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	struct sco_options opts;
+	int len, err = 0;
+
+	BT_DBG("sk %p", sk);
+
+	lock_sock(sk);
+
+	switch (optname) {
+	case SCO_OPTIONS:
+		if (sk->sk_state != BT_OPEN &&
+		    sk->sk_state != BT_BOUND &&
+		    sk->sk_state != BT_CONNECT2) {
+			err = -EINVAL;
+			break;
+		}
+
+		opts.mtu = 0;
+		opts.mode = SCO_MODE_CVSD;
+
+		len = min_t(unsigned int, sizeof(opts), optlen);
+		if (copy_from_user((char *) &opts, optval, len)) {
+			err = -EFAULT;
+			break;
+		}
+
+		if (opts.mtu != 0) {
+			err = -EINVAL;
+			break;
+		}
+
+		BT_DBG("mode %d", opts.mode);
+
+		if (opts.mode >= SCO_MODE_MAX) {
+			err = -EINVAL;
+			break;
+		}
+
+		sco_pi(sk)->mode = opts.mode;
+		break;
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	}
+
+	release_sock(sk);
+	return err;
+}
+
 static int sco_sock_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
 {
 	struct sock *sk = sock->sk;
@@ -684,6 +739,9 @@ static int sco_sock_setsockopt(struct socket *sock, int level, int optname, char
 
 	BT_DBG("sk %p", sk);
 
+	if (level == SOL_SCO)
+		return sco_sock_setsockopt_old(sock, optname, optval, optlen);
+
 	lock_sock(sk);
 
 	switch (optname) {
@@ -736,6 +794,7 @@ static int sco_sock_getsockopt_old(struct socket *sock, int optname, char __user
 		}
 
 		opts.mtu = sco_pi(sk)->conn->mtu;
+		opts.mode = sco_pi(sk)->mode;
 
 		BT_DBG("mtu %d", opts.mtu);
 
-- 
1.7.9.5

[PATCH v2 2/4] Bluetooth: Use mode to create SCO connection

[Frédéric Dalleau]

When an incoming SCO connection is requested, check the selected mode, and
reply appropriately. Mode should have been negotiated previously. For example,
in case of HFP, the codec is negotiated using AT commands on the RFCOMM
channel. This patch only changes replies for socket with defered setup enabled.

Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com>
---
 include/net/bluetooth/hci_core.h |    2 +-
 net/bluetooth/hci_event.c        |   21 +++++++++++++++++----
 net/bluetooth/sco.c              |    2 +-
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 90cf75a..494b660 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -582,7 +582,7 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst);
 int hci_conn_del(struct hci_conn *conn);
 void hci_conn_hash_flush(struct hci_dev *hdev);
 void hci_conn_check_pending(struct hci_dev *hdev);
-void hci_conn_accept(struct hci_conn *conn, int mask);
+void hci_conn_accept(struct hci_conn *conn, int mask, int mode);
 
 struct hci_chan *hci_chan_create(struct hci_conn *conn);
 void hci_chan_del(struct hci_chan *chan);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index d4fcba6..188bb83 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2095,7 +2095,7 @@ unlock:
 	hci_conn_check_pending(hdev);
 }
 
-void hci_conn_accept(struct hci_conn *conn, int mask)
+void hci_conn_accept(struct hci_conn *conn, int mask, int mode)
 {
 	struct hci_dev *hdev = conn->hdev;
 
@@ -2122,9 +2122,22 @@ void hci_conn_accept(struct hci_conn *conn, int mask)
 
 		cp.tx_bandwidth   = __constant_cpu_to_le32(0x00001f40);
 		cp.rx_bandwidth   = __constant_cpu_to_le32(0x00001f40);
-		cp.max_latency    = __constant_cpu_to_le16(0xffff);
-		cp.content_format = cpu_to_le16(hdev->voice_setting);
-		cp.retrans_effort = 0xff;
+
+		switch (mode) {
+		case 0:
+			cp.max_latency    = __constant_cpu_to_le16(0xffff);
+			cp.content_format = cpu_to_le16(hdev->voice_setting);
+			cp.retrans_effort = 0xff;
+			break;
+		case 1:
+			if (conn->pkt_type & ESCO_2EV3)
+				cp.max_latency = __constant_cpu_to_le16(0x0008);
+			else
+				cp.max_latency = __constant_cpu_to_le16(0x000D);
+			cp.content_format = __constant_cpu_to_le16(0x0003);
+			cp.retrans_effort = 0x02;
+			break;
+		}
 
 		hci_send_cmd(hdev, HCI_OP_ACCEPT_SYNC_CONN_REQ,
 			     sizeof(cp), &cp);
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index 927119e6..1527012 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -666,7 +666,7 @@ static int sco_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 
 	if (sk->sk_state == BT_CONNECT2 &&
 	    test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) {
-		hci_conn_accept(pi->conn->hcon, 0);
+		hci_conn_accept(pi->conn->hcon, 0, pi->mode);
 		sk->sk_state = BT_CONFIG;
 
 		release_sock(sk);
-- 
1.7.9.5

[PATCH v2 3/4] Bluetooth: Parameters for outgoing SCO connections

[Frédéric Dalleau]

In order to establish a transparent SCO connection, the correct settings must
be specified in the SetupSynchronousConnection request. For that, a bit is set
in ACL connection flags to set up the desired parameters. If this bit is not
set, a legacy SCO connection will be requested.
This patch uses T2 settings.

Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com>
---
 include/net/bluetooth/hci_core.h |    3 +++
 net/bluetooth/hci_conn.c         |   29 +++++++++++++++++++----------
 net/bluetooth/sco.c              |    3 +--
 3 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 494b660..039c263 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -443,6 +443,7 @@ enum {
 	HCI_CONN_SSP_ENABLED,
 	HCI_CONN_POWER_SAVE,
 	HCI_CONN_REMOTE_OOB,
+	HCI_CONN_SCO_TRANSPARENT,
 };
 
 static inline bool hci_conn_ssp_enabled(struct hci_conn *conn)
@@ -591,6 +592,8 @@ struct hci_chan *hci_chan_lookup_handle(struct hci_dev *hdev, __u16 handle);
 
 struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst,
 			     __u8 dst_type, __u8 sec_level, __u8 auth_type);
+struct hci_conn *hci_connect_sco(struct hci_dev *hdev, int type, bdaddr_t *dst,
+				 u8 codec);
 int hci_conn_check_link_mode(struct hci_conn *conn);
 int hci_conn_check_secure(struct hci_conn *conn, __u8 sec_level);
 int hci_conn_security(struct hci_conn *conn, __u8 sec_level, __u8 auth_type);
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 25bfce0..7f290ad 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -175,13 +175,22 @@ void hci_setup_sync(struct hci_conn *conn, __u16 handle)
 	conn->attempt++;
 
 	cp.handle   = cpu_to_le16(handle);
-	cp.pkt_type = cpu_to_le16(conn->pkt_type);
 
 	cp.tx_bandwidth   = __constant_cpu_to_le32(0x00001f40);
 	cp.rx_bandwidth   = __constant_cpu_to_le32(0x00001f40);
-	cp.max_latency    = __constant_cpu_to_le16(0xffff);
-	cp.voice_setting  = cpu_to_le16(hdev->voice_setting);
-	cp.retrans_effort = 0xff;
+
+	if (test_and_clear_bit(HCI_CONN_SCO_TRANSPARENT, &conn->flags)) {
+		cp.pkt_type       = __constant_cpu_to_le16(EDR_ESCO_MASK &
+							   ~ESCO_2EV3);
+		cp.max_latency    = __constant_cpu_to_le16(0x000d);
+		cp.voice_setting  = __constant_cpu_to_le16(0x0003);
+		cp.retrans_effort = 0x02;
+	} else {
+		cp.pkt_type       = cpu_to_le16(conn->pkt_type);
+		cp.max_latency    = __constant_cpu_to_le16(0xffff);
+		cp.voice_setting  = cpu_to_le16(hdev->voice_setting);
+		cp.retrans_effort = 0xff;
+	}
 
 	hci_send_cmd(hdev, HCI_OP_SETUP_SYNC_CONN, sizeof(cp), &cp);
 }
@@ -551,13 +560,13 @@ static struct hci_conn *hci_connect_acl(struct hci_dev *hdev, bdaddr_t *dst,
 	return acl;
 }
 
-static struct hci_conn *hci_connect_sco(struct hci_dev *hdev, int type,
-				bdaddr_t *dst, u8 sec_level, u8 auth_type)
+struct hci_conn *hci_connect_sco(struct hci_dev *hdev, int type, bdaddr_t *dst,
+				 u8 codec)
 {
 	struct hci_conn *acl;
 	struct hci_conn *sco;
 
-	acl = hci_connect_acl(hdev, dst, sec_level, auth_type);
+	acl = hci_connect_acl(hdev, dst, BT_SECURITY_LOW, HCI_AT_NO_BONDING);
 	if (IS_ERR(acl))
 		return acl;
 
@@ -575,6 +584,9 @@ static struct hci_conn *hci_connect_sco(struct hci_dev *hdev, int type,
 
 	hci_conn_hold(sco);
 
+	if (codec)
+		set_bit(HCI_CONN_SCO_TRANSPARENT, &sco->flags);
+
 	if (acl->state == BT_CONNECTED &&
 	    (sco->state == BT_OPEN || sco->state == BT_CLOSED)) {
 		set_bit(HCI_CONN_POWER_SAVE, &acl->flags);
@@ -603,9 +615,6 @@ struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst,
 		return hci_connect_le(hdev, dst, dst_type, sec_level, auth_type);
 	case ACL_LINK:
 		return hci_connect_acl(hdev, dst, sec_level, auth_type);
-	case SCO_LINK:
-	case ESCO_LINK:
-		return hci_connect_sco(hdev, type, dst, sec_level, auth_type);
 	}
 
 	return ERR_PTR(-EINVAL);
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index 1527012..3af07ce 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -176,8 +176,7 @@ static int sco_connect(struct sock *sk)
 	else
 		type = SCO_LINK;
 
-	hcon = hci_connect(hdev, type, dst, BDADDR_BREDR, BT_SECURITY_LOW,
-			   HCI_AT_NO_BONDING);
+	hcon = hci_connect_sco(hdev, type, dst, sco_pi(sk)->mode);
 	if (IS_ERR(hcon)) {
 		err = PTR_ERR(hcon);
 		goto done;
-- 
1.7.9.5

[PATCH v2 4/4] Bluetooth: Fallback transparent SCO from T2 to T1

[Frédéric Dalleau]

When initiating a transparent eSCO connection, make use of T2 settings at
first try. T2 is the recommended settings from HFP 1.6 WideBand Speech. Upon
connection failure, try T1 settings.
To know which of T2 or T1 should be used, the connection attempt index is used.
T2 failure is detected if Synchronous Connection Complete Event fails with
error 0x0d. This error code has been found experimentally by sending a T2
request to a T1 only SCO listener. It means "Connection Rejected due to
Limited resource".

Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com>
---
 net/bluetooth/hci_conn.c  |   11 ++++++++++-
 net/bluetooth/hci_event.c |    1 +
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 7f290ad..2172d42 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -179,12 +179,21 @@ void hci_setup_sync(struct hci_conn *conn, __u16 handle)
 	cp.tx_bandwidth   = __constant_cpu_to_le32(0x00001f40);
 	cp.rx_bandwidth   = __constant_cpu_to_le32(0x00001f40);
 
-	if (test_and_clear_bit(HCI_CONN_SCO_TRANSPARENT, &conn->flags)) {
+	if (conn->attempt == 1 &&
+	    test_bit(HCI_CONN_SCO_TRANSPARENT, &conn->flags)) {
 		cp.pkt_type       = __constant_cpu_to_le16(EDR_ESCO_MASK &
 							   ~ESCO_2EV3);
 		cp.max_latency    = __constant_cpu_to_le16(0x000d);
 		cp.voice_setting  = __constant_cpu_to_le16(0x0003);
 		cp.retrans_effort = 0x02;
+	} else if (conn->attempt == 2 &&
+		   test_bit(HCI_CONN_SCO_TRANSPARENT, &conn->flags)) {
+		cp.pkt_type       = __constant_cpu_to_le16(EDR_ESCO_MASK |
+							   ESCO_EV3);
+		cp.max_latency    = __constant_cpu_to_le16(0x0007);
+		cp.voice_setting  = __constant_cpu_to_le16(0x0003);
+		cp.retrans_effort = 0x02;
+		clear_bit(HCI_CONN_SCO_TRANSPARENT, &conn->flags);
 	} else {
 		cp.pkt_type       = cpu_to_le16(conn->pkt_type);
 		cp.max_latency    = __constant_cpu_to_le16(0xffff);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 188bb83..86ce811 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3379,6 +3379,7 @@ static void hci_sync_conn_complete_evt(struct hci_dev *hdev,
 		hci_conn_add_sysfs(conn);
 		break;
 
+	case 0x0d:	/* No resource available */
 	case 0x11:	/* Unsupported Feature or Parameter Value */
 	case 0x1c:	/* SCO interval rejected */
 	case 0x1a:	/* Unsupported Remote Feature */
-- 
1.7.9.5

Re: [PATCH v2 1/4] Bluetooth: Add option for SCO socket mode

[Johan Hedberg]

Hi Frédéric,

On Wed, Jan 30, 2013, Frédéric Dalleau wrote:
> +#define SCO_MODE_CVSD		0x00
> +#define SCO_MODE_TRANSPARENT	0x01
> +#define SCO_MODE_MAX            0x02

If you're going to have a MAX define better make it the real maximum
instead of max + 1.

> +		if (opts.mode >= SCO_MODE_MAX) {
> +			err = -EINVAL;
> +			break;
> +		}

It makes this check also look a bit nicer since you use > instead of >=

Johan

Re: [PATCH v2 2/4] Bluetooth: Use mode to create SCO connection

[Johan Hedberg]

Hi Frédéric,

On Wed, Jan 30, 2013, Frédéric Dalleau wrote:
> +		switch (mode) {
> +		case 0:
> +			cp.max_latency    = __constant_cpu_to_le16(0xffff);
> +			cp.content_format = cpu_to_le16(hdev->voice_setting);
> +			cp.retrans_effort = 0xff;
> +			break;
> +		case 1:
> +			if (conn->pkt_type & ESCO_2EV3)
> +				cp.max_latency = __constant_cpu_to_le16(0x0008);
> +			else
> +				cp.max_latency = __constant_cpu_to_le16(0x000D);
> +			cp.content_format = __constant_cpu_to_le16(0x0003);
> +			cp.retrans_effort = 0x02;
> +			break;
> +		}

Why are you using 0 and 1 here instead of your nice defines?

Johan