[Bluetooth] Add support for handling simple eSCO links

With the Bluetooth 1.2 specification the Extended SCO feature for
better audio connections was introduced. So far the Bluetooth core
wasn't able to handle any eSCO connections correctly. This patch
adds simple eSCO support while keeping backward compatibility with
older devices.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/hci_core.h

@@ -313,6 +313,7 @@ static inline struct hci_conn *hci_conn_hash_lookup_state(struct hci_dev *hdev,
 void hci_acl_connect(struct hci_conn *conn);
 void hci_acl_disconn(struct hci_conn *conn, __u8 reason);
 void hci_add_sco(struct hci_conn *conn, __u16 handle);
+void hci_setup_sync(struct hci_conn *conn, __u16 handle);
 
 struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst);
 int hci_conn_del(struct hci_conn *conn);

net/bluetooth/hci_conn.c

@@ -127,6 +127,28 @@ void hci_add_sco(struct hci_conn *conn, __u16 handle)
 	hci_send_cmd(hdev, HCI_OP_ADD_SCO, sizeof(cp), &cp);
 }
 
+void hci_setup_sync(struct hci_conn *conn, __u16 handle)
+{
+	struct hci_dev *hdev = conn->hdev;
+	struct hci_cp_setup_sync_conn cp;
+
+	BT_DBG("%p", conn);
+
+	conn->state = BT_CONNECT;
+	conn->out = 1;
+
+	cp.handle   = cpu_to_le16(handle);
+	cp.pkt_type = cpu_to_le16(hdev->esco_type);
+
+	cp.tx_bandwidth   = cpu_to_le32(0x00001f40);
+	cp.rx_bandwidth   = cpu_to_le32(0x00001f40);
+	cp.max_latency    = 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);
+}
+
 static void hci_conn_timeout(unsigned long arg)
 {
 	struct hci_conn *conn = (void *) arg;
@@ -141,7 +163,10 @@ static void hci_conn_timeout(unsigned long arg)
 
 	switch (conn->state) {
 	case BT_CONNECT:
+		if (conn->type == ACL_LINK)
 			hci_acl_connect_cancel(conn);
+		else
+			hci_acl_disconn(conn, 0x13);
 		break;
 	case BT_CONNECTED:
 		hci_acl_disconn(conn, 0x13);
@@ -328,8 +353,12 @@ struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst)
 	hci_conn_hold(sco);
 
 	if (acl->state == BT_CONNECTED &&
-			(sco->state == BT_OPEN || sco->state == BT_CLOSED))
+			(sco->state == BT_OPEN || sco->state == BT_CLOSED)) {
+		if (lmp_esco_capable(hdev))
+			hci_setup_sync(sco, acl->handle);
+		else
 			hci_add_sco(sco, acl->handle);
+	}
 
 	return sco;
 }

net/bluetooth/hci_core.c

@@ -1361,6 +1361,26 @@ static inline void hci_sched_sco(struct hci_dev *hdev)
 	}
 }
 
+static inline void hci_sched_esco(struct hci_dev *hdev)
+{
+	struct hci_conn *conn;
+	struct sk_buff *skb;
+	int quote;
+
+	BT_DBG("%s", hdev->name);
+
+	while (hdev->sco_cnt && (conn = hci_low_sent(hdev, ESCO_LINK, &quote))) {
+		while (quote-- && (skb = skb_dequeue(&conn->data_q))) {
+			BT_DBG("skb %p len %d", skb, skb->len);
+			hci_send_frame(skb);
+
+			conn->sent++;
+			if (conn->sent == ~0)
+				conn->sent = 0;
+		}
+	}
+}
+
 static void hci_tx_task(unsigned long arg)
 {
 	struct hci_dev *hdev = (struct hci_dev *) arg;
@@ -1376,6 +1396,8 @@ static void hci_tx_task(unsigned long arg)
 
 	hci_sched_sco(hdev);
 
+	hci_sched_esco(hdev);
+
 	/* Send next queued raw (unknown type) packet */
 	while ((skb = skb_dequeue(&hdev->raw_q)))
 		hci_send_frame(skb);

net/bluetooth/hci_event.c

@@ -511,11 +511,11 @@ static void hci_cs_add_sco(struct hci_dev *hdev, __u8 status)
 	struct hci_conn *acl, *sco;
 	__u16 handle;
 
+	BT_DBG("%s status 0x%x", hdev->name, status);
+
 	if (!status)
 		return;
 
-	BT_DBG("%s status 0x%x", hdev->name, status);
-
 	cp = hci_sent_cmd_data(hdev, HCI_OP_ADD_SCO);
 	if (!cp)
 		return;
@@ -544,7 +544,34 @@ static void hci_cs_remote_name_req(struct hci_dev *hdev, __u8 status)
 
 static void hci_cs_setup_sync_conn(struct hci_dev *hdev, __u8 status)
 {
+	struct hci_cp_setup_sync_conn *cp;
+	struct hci_conn *acl, *sco;
+	__u16 handle;
+
 	BT_DBG("%s status 0x%x", hdev->name, status);
+
+	if (!status)
+		return;
+
+	cp = hci_sent_cmd_data(hdev, HCI_OP_SETUP_SYNC_CONN);
+	if (!cp)
+		return;
+
+	handle = __le16_to_cpu(cp->handle);
+
+	BT_DBG("%s handle %d", hdev->name, handle);
+
+	hci_dev_lock(hdev);
+
+	acl = hci_conn_hash_lookup_handle(hdev, handle);
+	if (acl && (sco = acl->link)) {
+		sco->state = BT_CLOSED;
+
+		hci_proto_connect_cfm(sco, status);
+		hci_conn_del(sco);
+	}
+
+	hci_dev_unlock(hdev);
 }
 
 static void hci_cs_sniff_mode(struct hci_dev *hdev, __u8 status)
@@ -692,9 +719,12 @@ static inline void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *s
 	if (conn->type == ACL_LINK) {
 		struct hci_conn *sco = conn->link;
 		if (sco) {
-			if (!ev->status)
+			if (!ev->status) {
+				if (lmp_esco_capable(hdev))
+					hci_setup_sync(sco, conn->handle);
+				else
 					hci_add_sco(sco, conn->handle);
-			else {
+			} else {
 				hci_proto_connect_cfm(sco, ev->status);
 				hci_conn_del(sco);
 			}
@@ -724,9 +754,9 @@ static inline void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *sk
 	if (mask & HCI_LM_ACCEPT) {
 		/* Connection accepted */
 		struct hci_conn *conn;
-		struct hci_cp_accept_conn_req cp;
 
 		hci_dev_lock(hdev);
+
 		conn = hci_conn_hash_lookup_ba(hdev, ev->link_type, &ev->bdaddr);
 		if (!conn) {
 			if (!(conn = hci_conn_add(hdev, ev->link_type, &ev->bdaddr))) {
@@ -735,10 +765,15 @@ static inline void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *sk
 				return;
 			}
 		}
+
 		memcpy(conn->dev_class, ev->dev_class, 3);
 		conn->state = BT_CONNECT;
+
 		hci_dev_unlock(hdev);
 
+		if (ev->link_type == ACL_LINK || !lmp_esco_capable(hdev)) {
+			struct hci_cp_accept_conn_req cp;
+
 			bacpy(&cp.bdaddr, &ev->bdaddr);
 
 			if (lmp_rswitch_capable(hdev) && (mask & HCI_LM_MASTER))
@@ -746,7 +781,23 @@ static inline void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *sk
 			else
 				cp.role = 0x01; /* Remain slave */
 
-		hci_send_cmd(hdev, HCI_OP_ACCEPT_CONN_REQ, sizeof(cp), &cp);
+			hci_send_cmd(hdev, HCI_OP_ACCEPT_CONN_REQ,
+							sizeof(cp), &cp);
+		} else {
+			struct hci_cp_accept_sync_conn_req cp;
+
+			bacpy(&cp.bdaddr, &ev->bdaddr);
+			cp.pkt_type = cpu_to_le16(hdev->esco_type);
+
+			cp.tx_bandwidth   = cpu_to_le32(0x00001f40);
+			cp.rx_bandwidth   = cpu_to_le32(0x00001f40);
+			cp.max_latency    = cpu_to_le16(0xffff);
+			cp.content_format = cpu_to_le16(hdev->voice_setting);
+			cp.retrans_effort = 0xff;
+
+			hci_send_cmd(hdev, HCI_OP_ACCEPT_SYNC_CONN_REQ,
+							sizeof(cp), &cp);
+		}
 	} else {
 		/* Connection rejected */
 		struct hci_cp_reject_conn_req cp;
@@ -1254,7 +1305,29 @@ static inline void hci_remote_ext_features_evt(struct hci_dev *hdev, struct sk_b
 
 static inline void hci_sync_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
-	BT_DBG("%s", hdev->name);
+	struct hci_ev_sync_conn_complete *ev = (void *) skb->data;
+	struct hci_conn *conn;
+
+	BT_DBG("%s status %d", hdev->name, ev->status);
+
+	hci_dev_lock(hdev);
+
+	conn = hci_conn_hash_lookup_ba(hdev, ev->link_type, &ev->bdaddr);
+	if (!conn)
+		goto unlock;
+
+	if (!ev->status) {
+		conn->handle = __le16_to_cpu(ev->handle);
+		conn->state  = BT_CONNECTED;
+	} else
+		conn->state = BT_CLOSED;
+
+	hci_proto_connect_cfm(conn, ev->status);
+	if (ev->status)
+		hci_conn_del(conn);
+
+unlock:
+	hci_dev_unlock(hdev);
 }
 
 static inline void hci_sync_conn_changed_evt(struct hci_dev *hdev, struct sk_buff *skb)

net/bluetooth/sco.c

@@ -189,7 +189,7 @@ static int sco_connect(struct sock *sk)
 	struct sco_conn *conn;
 	struct hci_conn *hcon;
 	struct hci_dev  *hdev;
-	int err = 0;
+	int err, type;
 
 	BT_DBG("%s -> %s", batostr(src), batostr(dst));
 
@@ -200,7 +200,9 @@ static int sco_connect(struct sock *sk)
 
 	err = -ENOMEM;
 
-	hcon = hci_connect(hdev, SCO_LINK, dst);
+	type = lmp_esco_capable(hdev) ? ESCO_LINK : SCO_LINK;
+
+	hcon = hci_connect(hdev, type, dst);
 	if (!hcon)
 		goto done;
 
@@ -224,6 +226,7 @@ static int sco_connect(struct sock *sk)
 		sk->sk_state = BT_CONNECT;
 		sco_sock_set_timer(sk, sk->sk_sndtimeo);
 	}
+
 done:
 	hci_dev_unlock_bh(hdev);
 	hci_dev_put(hdev);
@@ -846,7 +849,7 @@ static int sco_connect_cfm(struct hci_conn *hcon, __u8 status)
 {
 	BT_DBG("hcon %p bdaddr %s status %d", hcon, batostr(&hcon->dst), status);
 
-	if (hcon->type != SCO_LINK)
+	if (hcon->type != SCO_LINK && hcon->type != ESCO_LINK)
 		return 0;
 
 	if (!status) {
@@ -865,10 +868,11 @@ static int sco_disconn_ind(struct hci_conn *hcon, __u8 reason)
 {
 	BT_DBG("hcon %p reason %d", hcon, reason);
 
-	if (hcon->type != SCO_LINK)
+	if (hcon->type != SCO_LINK && hcon->type != ESCO_LINK)
 		return 0;
 
 	sco_conn_del(hcon, bt_err(reason));
+
 	return 0;
 }