Bluetooth: Enable 6LoWPAN support for BT LE devices

This is initial version of
http://tools.ietf.org/html/draft-ietf-6lo-btle-00

By default the 6LoWPAN support is not activated and user
needs to tweak /sys/kernel/debug/bluetooth/hci0/6lowpan
file.

The kernel needs IPv6 support before 6LoWPAN is usable.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/hci.h

@@ -131,6 +131,7 @@ enum {
 	HCI_PERIODIC_INQ,
 	HCI_FAST_CONNECTABLE,
 	HCI_BREDR_ENABLED,
+	HCI_6LOWPAN_ENABLED,
 };
 
 /* A mask for the flags that are supposed to remain when a reset happens

include/net/bluetooth/hci_core.h

@@ -448,6 +448,7 @@ enum {
 	HCI_CONN_SSP_ENABLED,
 	HCI_CONN_POWER_SAVE,
 	HCI_CONN_REMOTE_OOB,
+	HCI_CONN_6LOWPAN,
 };
 
 static inline bool hci_conn_ssp_enabled(struct hci_conn *conn)

include/net/bluetooth/l2cap.h

@@ -136,6 +136,7 @@ struct l2cap_conninfo {
 #define L2CAP_FC_L2CAP		0x02
 #define L2CAP_FC_CONNLESS	0x04
 #define L2CAP_FC_A2MP		0x08
+#define L2CAP_FC_6LOWPAN        0x3e /* reserved and temporary value */
 
 /* L2CAP Control Field bit masks */
 #define L2CAP_CTRL_SAR			0xC000

net/bluetooth/6lowpan.h

@@ -0,0 +1,26 @@
+/*
+   Copyright (c) 2013 Intel Corp.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License version 2 and
+   only version 2 as published by the Free Software Foundation.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+*/
+
+#ifndef __6LOWPAN_H
+#define __6LOWPAN_H
+
+#include <linux/skbuff.h>
+#include <net/bluetooth/l2cap.h>
+
+int bt_6lowpan_recv(struct l2cap_conn *conn, struct sk_buff *skb);
+int bt_6lowpan_add_conn(struct l2cap_conn *conn);
+int bt_6lowpan_del_conn(struct l2cap_conn *conn);
+int bt_6lowpan_init(void);
+void bt_6lowpan_cleanup(void);
+
+#endif /* __6LOWPAN_H */

net/bluetooth/Makefile

@@ -10,6 +10,10 @@ obj-$(CONFIG_BT_HIDP)	+= hidp/
 
 bluetooth-y := af_bluetooth.o hci_core.o hci_conn.o hci_event.o mgmt.o \
 	hci_sock.o hci_sysfs.o l2cap_core.o l2cap_sock.o smp.o sco.o lib.o \
-	a2mp.o amp.o
+	a2mp.o amp.o 6lowpan.o
+
+ifeq ($(CONFIG_IEEE802154_6LOWPAN),)
+  bluetooth-y +=  ../ieee802154/6lowpan_iphc.o
+endif
 
 subdir-ccflags-y += -D__CHECK_ENDIAN__

net/bluetooth/hci_event.c

@@ -3533,6 +3533,9 @@ static void hci_le_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 	conn->handle = __le16_to_cpu(ev->handle);
 	conn->state = BT_CONNECTED;
 
+	if (test_bit(HCI_6LOWPAN_ENABLED, &hdev->dev_flags))
+		set_bit(HCI_CONN_6LOWPAN, &conn->flags);
+
 	hci_conn_add_sysfs(conn);
 
 	hci_proto_connect_cfm(conn, ev->status);

net/bluetooth/l2cap_core.c

@@ -40,6 +40,7 @@
 #include "smp.h"
 #include "a2mp.h"
 #include "amp.h"
+#include "6lowpan.h"
 
 bool disable_ertm;
 
@@ -1468,6 +1469,8 @@ static void l2cap_le_conn_ready(struct l2cap_conn *conn)
 
 	BT_DBG("");
 
+	bt_6lowpan_add_conn(conn);
+
 	/* Check if we have socket listening on cid */
 	pchan = l2cap_global_chan_by_scid(BT_LISTEN, L2CAP_CID_ATT,
 					  &hcon->src, &hcon->dst);
@@ -7119,6 +7122,10 @@ static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb)
 			l2cap_conn_del(conn->hcon, EACCES);
 		break;
 
+	case L2CAP_FC_6LOWPAN:
+		bt_6lowpan_recv(conn, skb);
+		break;
+
 	default:
 		l2cap_data_channel(conn, cid, skb);
 		break;
@@ -7186,6 +7193,8 @@ void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason)
 {
 	BT_DBG("hcon %p reason %d", hcon, reason);
 
+	bt_6lowpan_del_conn(hcon->l2cap_data);
+
 	l2cap_conn_del(hcon, bt_to_errno(reason));
 }
 
@@ -7467,11 +7476,14 @@ int __init l2cap_init(void)
 	debugfs_create_u16("l2cap_le_default_mps", 0466, bt_debugfs,
 			   &le_default_mps);
 
+	bt_6lowpan_init();
+
 	return 0;
 }
 
 void l2cap_exit(void)
 {
+	bt_6lowpan_cleanup();
 	debugfs_remove(l2cap_debugfs);
 	l2cap_cleanup_sockets();
 }