Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 4554 insertions, 0 deletions

diff --git a/net/bluetooth/rfcomm/Kconfig b/net/bluetooth/rfcomm/Kconfig
new file mode 100644
index 000000000..9b9953ebf
--- /dev/null
+++ b/net/bluetooth/rfcomm/Kconfig
@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config BT_RFCOMM
+	tristate "RFCOMM protocol support"
+	depends on BT_BREDR
+	help
+	  RFCOMM provides connection oriented stream transport.  RFCOMM
+	  support is required for Dialup Networking, OBEX and other Bluetooth
+	  applications.
+
+	  Say Y here to compile RFCOMM support into the kernel or say M to
+	  compile it as module (rfcomm).
+
+config BT_RFCOMM_TTY
+	bool "RFCOMM TTY support"
+	depends on BT_RFCOMM
+	depends on TTY
+	help
+	  This option enables TTY emulation support for RFCOMM channels.
+
diff --git a/net/bluetooth/rfcomm/Makefile b/net/bluetooth/rfcomm/Makefile
new file mode 100644
index 000000000..593e5c48c
--- /dev/null
+++ b/net/bluetooth/rfcomm/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the Linux Bluetooth RFCOMM layer.
+#
+
+obj-$(CONFIG_BT_RFCOMM) += rfcomm.o
+
+rfcomm-y			:= core.o sock.o
+rfcomm-$(CONFIG_BT_RFCOMM_TTY)	+= tty.o
diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
new file mode 100644
index 000000000..8d6fce900
--- /dev/null
+++ b/net/bluetooth/rfcomm/core.c
@@ -0,0 +1,2281 @@
+/*
+   RFCOMM implementation for Linux Bluetooth stack (BlueZ).
+   Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com>
+   Copyright (C) 2002 Marcel Holtmann <marcel@holtmann.org>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License version 2 as
+   published by the Free Software Foundation;
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
+   IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
+   CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
+   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+   ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
+   COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
+   SOFTWARE IS DISCLAIMED.
+*/
+
+/*
+ * Bluetooth RFCOMM core.
+ */
+
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/kthread.h>
+#include <asm/unaligned.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+#include <net/bluetooth/l2cap.h>
+#include <net/bluetooth/rfcomm.h>
+
+#define VERSION "1.11"
+
+static bool disable_cfc;
+static bool l2cap_ertm;
+static int channel_mtu = -1;
+
+static struct task_struct *rfcomm_thread;
+
+static DEFINE_MUTEX(rfcomm_mutex);
+#define rfcomm_lock()	mutex_lock(&rfcomm_mutex)
+#define rfcomm_unlock()	mutex_unlock(&rfcomm_mutex)
+
+
+static LIST_HEAD(session_list);
+
+static int rfcomm_send_frame(struct rfcomm_session *s, u8 *data, int len);
+static int rfcomm_send_sabm(struct rfcomm_session *s, u8 dlci);
+static int rfcomm_send_disc(struct rfcomm_session *s, u8 dlci);
+static int rfcomm_queue_disc(struct rfcomm_dlc *d);
+static int rfcomm_send_nsc(struct rfcomm_session *s, int cr, u8 type);
+static int rfcomm_send_pn(struct rfcomm_session *s, int cr, struct rfcomm_dlc *d);
+static int rfcomm_send_msc(struct rfcomm_session *s, int cr, u8 dlci, u8 v24_sig);
+static int rfcomm_send_test(struct rfcomm_session *s, int cr, u8 *pattern, int len);
+static int rfcomm_send_credits(struct rfcomm_session *s, u8 addr, u8 credits);
+static void rfcomm_make_uih(struct sk_buff *skb, u8 addr);
+
+static void rfcomm_process_connect(struct rfcomm_session *s);
+
+static struct rfcomm_session *rfcomm_session_create(bdaddr_t *src,
+							bdaddr_t *dst,
+							u8 sec_level,
+							int *err);
+static struct rfcomm_session *rfcomm_session_get(bdaddr_t *src, bdaddr_t *dst);
+static struct rfcomm_session *rfcomm_session_del(struct rfcomm_session *s);
+
+/* ---- RFCOMM frame parsing macros ---- */
+#define __get_dlci(b)     ((b & 0xfc) >> 2)
+#define __get_type(b)     ((b & 0xef))
+
+#define __test_ea(b)      ((b & 0x01))
+#define __test_cr(b)      (!!(b & 0x02))
+#define __test_pf(b)      (!!(b & 0x10))
+
+#define __session_dir(s)  ((s)->initiator ? 0x00 : 0x01)
+
+#define __addr(cr, dlci)       (((dlci & 0x3f) << 2) | (cr << 1) | 0x01)
+#define __ctrl(type, pf)       (((type & 0xef) | (pf << 4)))
+#define __dlci(dir, chn)       (((chn & 0x1f) << 1) | dir)
+#define __srv_channel(dlci)    (dlci >> 1)
+
+#define __len8(len)       (((len) << 1) | 1)
+#define __len16(len)      ((len) << 1)
+
+/* MCC macros */
+#define __mcc_type(cr, type)   (((type << 2) | (cr << 1) | 0x01))
+#define __get_mcc_type(b) ((b & 0xfc) >> 2)
+#define __get_mcc_len(b)  ((b & 0xfe) >> 1)
+
+/* RPN macros */
+#define __rpn_line_settings(data, stop, parity)  ((data & 0x3) | ((stop & 0x1) << 2) | ((parity & 0x7) << 3))
+#define __get_rpn_data_bits(line) ((line) & 0x3)
+#define __get_rpn_stop_bits(line) (((line) >> 2) & 0x1)
+#define __get_rpn_parity(line)    (((line) >> 3) & 0x7)
+
+static DECLARE_WAIT_QUEUE_HEAD(rfcomm_wq);
+
+static void rfcomm_schedule(void)
+{
+	wake_up_all(&rfcomm_wq);
+}
+
+/* ---- RFCOMM FCS computation ---- */
+
+/* reversed, 8-bit, poly=0x07 */
+static unsigned char rfcomm_crc_table[256] = {
+	0x00, 0x91, 0xe3, 0x72, 0x07, 0x96, 0xe4, 0x75,
+	0x0e, 0x9f, 0xed, 0x7c, 0x09, 0x98, 0xea, 0x7b,
+	0x1c, 0x8d, 0xff, 0x6e, 0x1b, 0x8a, 0xf8, 0x69,
+	0x12, 0x83, 0xf1, 0x60, 0x15, 0x84, 0xf6, 0x67,
+
+	0x38, 0xa9, 0xdb, 0x4a, 0x3f, 0xae, 0xdc, 0x4d,
+	0x36, 0xa7, 0xd5, 0x44, 0x31, 0xa0, 0xd2, 0x43,
+	0x24, 0xb5, 0xc7, 0x56, 0x23, 0xb2, 0xc0, 0x51,
+	0x2a, 0xbb, 0xc9, 0x58, 0x2d, 0xbc, 0xce, 0x5f,
+
+	0x70, 0xe1, 0x93, 0x02, 0x77, 0xe6, 0x94, 0x05,
+	0x7e, 0xef, 0x9d, 0x0c, 0x79, 0xe8, 0x9a, 0x0b,
+	0x6c, 0xfd, 0x8f, 0x1e, 0x6b, 0xfa, 0x88, 0x19,
+	0x62, 0xf3, 0x81, 0x10, 0x65, 0xf4, 0x86, 0x17,
+
+	0x48, 0xd9, 0xab, 0x3a, 0x4f, 0xde, 0xac, 0x3d,
+	0x46, 0xd7, 0xa5, 0x34, 0x41, 0xd0, 0xa2, 0x33,
+	0x54, 0xc5, 0xb7, 0x26, 0x53, 0xc2, 0xb0, 0x21,
+	0x5a, 0xcb, 0xb9, 0x28, 0x5d, 0xcc, 0xbe, 0x2f,
+
+	0xe0, 0x71, 0x03, 0x92, 0xe7, 0x76, 0x04, 0x95,
+	0xee, 0x7f, 0x0d, 0x9c, 0xe9, 0x78, 0x0a, 0x9b,
+	0xfc, 0x6d, 0x1f, 0x8e, 0xfb, 0x6a, 0x18, 0x89,
+	0xf2, 0x63, 0x11, 0x80, 0xf5, 0x64, 0x16, 0x87,
+
+	0xd8, 0x49, 0x3b, 0xaa, 0xdf, 0x4e, 0x3c, 0xad,
+	0xd6, 0x47, 0x35, 0xa4, 0xd1, 0x40, 0x32, 0xa3,
+	0xc4, 0x55, 0x27, 0xb6, 0xc3, 0x52, 0x20, 0xb1,
+	0xca, 0x5b, 0x29, 0xb8, 0xcd, 0x5c, 0x2e, 0xbf,
+
+	0x90, 0x01, 0x73, 0xe2, 0x97, 0x06, 0x74, 0xe5,
+	0x9e, 0x0f, 0x7d, 0xec, 0x99, 0x08, 0x7a, 0xeb,
+	0x8c, 0x1d, 0x6f, 0xfe, 0x8b, 0x1a, 0x68, 0xf9,
+	0x82, 0x13, 0x61, 0xf0, 0x85, 0x14, 0x66, 0xf7,
+
+	0xa8, 0x39, 0x4b, 0xda, 0xaf, 0x3e, 0x4c, 0xdd,
+	0xa6, 0x37, 0x45, 0xd4, 0xa1, 0x30, 0x42, 0xd3,
+	0xb4, 0x25, 0x57, 0xc6, 0xb3, 0x22, 0x50, 0xc1,
+	0xba, 0x2b, 0x59, 0xc8, 0xbd, 0x2c, 0x5e, 0xcf
+};
+
+/* CRC on 2 bytes */
+#define __crc(data) (rfcomm_crc_table[rfcomm_crc_table[0xff ^ data[0]] ^ data[1]])
+
+/* FCS on 2 bytes */
+static inline u8 __fcs(u8 *data)
+{
+	return 0xff - __crc(data);
+}
+
+/* FCS on 3 bytes */
+static inline u8 __fcs2(u8 *data)
+{
+	return 0xff - rfcomm_crc_table[__crc(data) ^ data[2]];
+}
+
+/* Check FCS */
+static inline int __check_fcs(u8 *data, int type, u8 fcs)
+{
+	u8 f = __crc(data);
+
+	if (type != RFCOMM_UIH)
+		f = rfcomm_crc_table[f ^ data[2]];
+
+	return rfcomm_crc_table[f ^ fcs] != 0xcf;
+}
+
+/* ---- L2CAP callbacks ---- */
+static void rfcomm_l2state_change(struct sock *sk)
+{
+	BT_DBG("%p state %d", sk, sk->sk_state);
+	rfcomm_schedule();
+}
+
+static void rfcomm_l2data_ready(struct sock *sk)
+{
+	BT_DBG("%p", sk);
+	rfcomm_schedule();
+}
+
+static int rfcomm_l2sock_create(struct socket **sock)
+{
+	int err;
+
+	BT_DBG("");
+
+	err = sock_create_kern(&init_net, PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP, sock);
+	if (!err) {
+		struct sock *sk = (*sock)->sk;
+		sk->sk_data_ready   = rfcomm_l2data_ready;
+		sk->sk_state_change = rfcomm_l2state_change;
+	}
+	return err;
+}
+
+static int rfcomm_check_security(struct rfcomm_dlc *d)
+{
+	struct sock *sk = d->session->sock->sk;
+	struct l2cap_conn *conn = l2cap_pi(sk)->chan->conn;
+
+	__u8 auth_type;
+
+	switch (d->sec_level) {
+	case BT_SECURITY_HIGH:
+	case BT_SECURITY_FIPS:
+		auth_type = HCI_AT_GENERAL_BONDING_MITM;
+		break;
+	case BT_SECURITY_MEDIUM:
+		auth_type = HCI_AT_GENERAL_BONDING;
+		break;
+	default:
+		auth_type = HCI_AT_NO_BONDING;
+		break;
+	}
+
+	return hci_conn_security(conn->hcon, d->sec_level, auth_type,
+				 d->out);
+}
+
+static void rfcomm_session_timeout(struct timer_list *t)
+{
+	struct rfcomm_session *s = from_timer(s, t, timer);
+
+	BT_DBG("session %p state %ld", s, s->state);
+
+	set_bit(RFCOMM_TIMED_OUT, &s->flags);
+	rfcomm_schedule();
+}
+
+static void rfcomm_session_set_timer(struct rfcomm_session *s, long timeout)
+{
+	BT_DBG("session %p state %ld timeout %ld", s, s->state, timeout);
+
+	mod_timer(&s->timer, jiffies + timeout);
+}
+
+static void rfcomm_session_clear_timer(struct rfcomm_session *s)
+{
+	BT_DBG("session %p state %ld", s, s->state);
+
+	del_timer_sync(&s->timer);
+}
+
+/* ---- RFCOMM DLCs ---- */
+static void rfcomm_dlc_timeout(struct timer_list *t)
+{
+	struct rfcomm_dlc *d = from_timer(d, t, timer);
+
+	BT_DBG("dlc %p state %ld", d, d->state);
+
+	set_bit(RFCOMM_TIMED_OUT, &d->flags);
+	rfcomm_dlc_put(d);
+	rfcomm_schedule();
+}
+
+static void rfcomm_dlc_set_timer(struct rfcomm_dlc *d, long timeout)
+{
+	BT_DBG("dlc %p state %ld timeout %ld", d, d->state, timeout);
+
+	if (!mod_timer(&d->timer, jiffies + timeout))
+		rfcomm_dlc_hold(d);
+}
+
+static void rfcomm_dlc_clear_timer(struct rfcomm_dlc *d)
+{
+	BT_DBG("dlc %p state %ld", d, d->state);
+
+	if (del_timer(&d->timer))
+		rfcomm_dlc_put(d);
+}
+
+static void rfcomm_dlc_clear_state(struct rfcomm_dlc *d)
+{
+	BT_DBG("%p", d);
+
+	d->state      = BT_OPEN;
+	d->flags      = 0;
+	d->mscex      = 0;
+	d->sec_level  = BT_SECURITY_LOW;
+	d->mtu        = RFCOMM_DEFAULT_MTU;
+	d->v24_sig    = RFCOMM_V24_RTC | RFCOMM_V24_RTR | RFCOMM_V24_DV;
+
+	d->cfc        = RFCOMM_CFC_DISABLED;
+	d->rx_credits = RFCOMM_DEFAULT_CREDITS;
+}
+
+struct rfcomm_dlc *rfcomm_dlc_alloc(gfp_t prio)
+{
+	struct rfcomm_dlc *d = kzalloc(sizeof(*d), prio);
+
+	if (!d)
+		return NULL;
+
+	timer_setup(&d->timer, rfcomm_dlc_timeout, 0);
+
+	skb_queue_head_init(&d->tx_queue);
+	mutex_init(&d->lock);
+	refcount_set(&d->refcnt, 1);
+
+	rfcomm_dlc_clear_state(d);
+
+	BT_DBG("%p", d);
+
+	return d;
+}
+
+void rfcomm_dlc_free(struct rfcomm_dlc *d)
+{
+	BT_DBG("%p", d);
+
+	skb_queue_purge(&d->tx_queue);
+	kfree(d);
+}
+
+static void rfcomm_dlc_link(struct rfcomm_session *s, struct rfcomm_dlc *d)
+{
+	BT_DBG("dlc %p session %p", d, s);
+
+	rfcomm_session_clear_timer(s);
+	rfcomm_dlc_hold(d);
+	list_add(&d->list, &s->dlcs);
+	d->session = s;
+}
+
+static void rfcomm_dlc_unlink(struct rfcomm_dlc *d)
+{
+	struct rfcomm_session *s = d->session;
+
+	BT_DBG("dlc %p refcnt %d session %p", d, refcount_read(&d->refcnt), s);
+
+	list_del(&d->list);
+	d->session = NULL;
+	rfcomm_dlc_put(d);
+
+	if (list_empty(&s->dlcs))
+		rfcomm_session_set_timer(s, RFCOMM_IDLE_TIMEOUT);
+}
+
+static struct rfcomm_dlc *rfcomm_dlc_get(struct rfcomm_session *s, u8 dlci)
+{
+	struct rfcomm_dlc *d;
+
+	list_for_each_entry(d, &s->dlcs, list)
+		if (d->dlci == dlci)
+			return d;
+
+	return NULL;
+}
+
+static int rfcomm_check_channel(u8 channel)
+{
+	return channel < 1 || channel > 30;
+}
+
+static int __rfcomm_dlc_open(struct rfcomm_dlc *d, bdaddr_t *src, bdaddr_t *dst, u8 channel)
+{
+	struct rfcomm_session *s;
+	int err = 0;
+	u8 dlci;
+
+	BT_DBG("dlc %p state %ld %pMR -> %pMR channel %d",
+	       d, d->state, src, dst, channel);
+
+	if (rfcomm_check_channel(channel))
+		return -EINVAL;
+
+	if (d->state != BT_OPEN && d->state != BT_CLOSED)
+		return 0;
+
+	s = rfcomm_session_get(src, dst);
+	if (!s) {
+		s = rfcomm_session_create(src, dst, d->sec_level, &err);
+		if (!s)
+			return err;
+	}
+
+	dlci = __dlci(__session_dir(s), channel);
+
+	/* Check if DLCI already exists */
+	if (rfcomm_dlc_get(s, dlci))
+		return -EBUSY;
+
+	rfcomm_dlc_clear_state(d);
+
+	d->dlci     = dlci;
+	d->addr     = __addr(s->initiator, dlci);
+	d->priority = 7;
+
+	d->state = BT_CONFIG;
+	rfcomm_dlc_link(s, d);
+
+	d->out = 1;
+
+	d->mtu = s->mtu;
+	d->cfc = (s->cfc == RFCOMM_CFC_UNKNOWN) ? 0 : s->cfc;
+
+	if (s->state == BT_CONNECTED) {
+		if (rfcomm_check_security(d))
+			rfcomm_send_pn(s, 1, d);
+		else
+			set_bit(RFCOMM_AUTH_PENDING, &d->flags);
+	}
+
+	rfcomm_dlc_set_timer(d, RFCOMM_CONN_TIMEOUT);
+
+	return 0;
+}
+
+int rfcomm_dlc_open(struct rfcomm_dlc *d, bdaddr_t *src, bdaddr_t *dst, u8 channel)
+{
+	int r;
+
+	rfcomm_lock();
+
+	r = __rfcomm_dlc_open(d, src, dst, channel);
+
+	rfcomm_unlock();
+	return r;
+}
+
+static void __rfcomm_dlc_disconn(struct rfcomm_dlc *d)
+{
+	struct rfcomm_session *s = d->session;
+
+	d->state = BT_DISCONN;
+	if (skb_queue_empty(&d->tx_queue)) {
+		rfcomm_send_disc(s, d->dlci);
+		rfcomm_dlc_set_timer(d, RFCOMM_DISC_TIMEOUT);
+	} else {
+		rfcomm_queue_disc(d);
+		rfcomm_dlc_set_timer(d, RFCOMM_DISC_TIMEOUT * 2);
+	}
+}
+
+static int __rfcomm_dlc_close(struct rfcomm_dlc *d, int err)
+{
+	struct rfcomm_session *s = d->session;
+	if (!s)
+		return 0;
+
+	BT_DBG("dlc %p state %ld dlci %d err %d session %p",
+			d, d->state, d->dlci, err, s);
+
+	switch (d->state) {
+	case BT_CONNECT:
+	case BT_CONFIG:
+	case BT_OPEN:
+	case BT_CONNECT2:
+		if (test_and_clear_bit(RFCOMM_DEFER_SETUP, &d->flags)) {
+			set_bit(RFCOMM_AUTH_REJECT, &d->flags);
+			rfcomm_schedule();
+			return 0;
+		}
+	}
+
+	switch (d->state) {
+	case BT_CONNECT:
+	case BT_CONNECTED:
+		__rfcomm_dlc_disconn(d);
+		break;
+
+	case BT_CONFIG:
+		if (s->state != BT_BOUND) {
+			__rfcomm_dlc_disconn(d);
+			break;
+		}
+		/* if closing a dlc in a session that hasn't been started,
+		 * just close and unlink the dlc
+		 */
+		fallthrough;
+
+	default:
+		rfcomm_dlc_clear_timer(d);
+
+		rfcomm_dlc_lock(d);
+		d->state = BT_CLOSED;
+		d->state_change(d, err);
+		rfcomm_dlc_unlock(d);
+
+		skb_queue_purge(&d->tx_queue);
+		rfcomm_dlc_unlink(d);
+	}
+
+	return 0;
+}
+
+int rfcomm_dlc_close(struct rfcomm_dlc *d, int err)
+{
+	int r = 0;
+	struct rfcomm_dlc *d_list;
+	struct rfcomm_session *s, *s_list;
+
+	BT_DBG("dlc %p state %ld dlci %d err %d", d, d->state, d->dlci, err);
+
+	rfcomm_lock();
+
+	s = d->session;
+	if (!s)
+		goto no_session;
+
+	/* after waiting on the mutex check the session still exists
+	 * then check the dlc still exists
+	 */
+	list_for_each_entry(s_list, &session_list, list) {
+		if (s_list == s) {
+			list_for_each_entry(d_list, &s->dlcs, list) {
+				if (d_list == d) {
+					r = __rfcomm_dlc_close(d, err);
+					break;
+				}
+			}
+			break;
+		}
+	}
+
+no_session:
+	rfcomm_unlock();
+	return r;
+}
+
+struct rfcomm_dlc *rfcomm_dlc_exists(bdaddr_t *src, bdaddr_t *dst, u8 channel)
+{
+	struct rfcomm_session *s;
+	struct rfcomm_dlc *dlc = NULL;
+	u8 dlci;
+
+	if (rfcomm_check_channel(channel))
+		return ERR_PTR(-EINVAL);
+
+	rfcomm_lock();
+	s = rfcomm_session_get(src, dst);
+	if (s) {
+		dlci = __dlci(__session_dir(s), channel);
+		dlc = rfcomm_dlc_get(s, dlci);
+	}
+	rfcomm_unlock();
+	return dlc;
+}
+
+static int rfcomm_dlc_send_frag(struct rfcomm_dlc *d, struct sk_buff *frag)
+{
+	int len = frag->len;
+
+	BT_DBG("dlc %p mtu %d len %d", d, d->mtu, len);
+
+	if (len > d->mtu)
+		return -EINVAL;
+
+	rfcomm_make_uih(frag, d->addr);
+	__skb_queue_tail(&d->tx_queue, frag);
+
+	return len;
+}
+
+int rfcomm_dlc_send(struct rfcomm_dlc *d, struct sk_buff *skb)
+{
+	unsigned long flags;
+	struct sk_buff *frag, *next;
+	int len;
+
+	if (d->state != BT_CONNECTED)
+		return -ENOTCONN;
+
+	frag = skb_shinfo(skb)->frag_list;
+	skb_shinfo(skb)->frag_list = NULL;
+
+	/* Queue all fragments atomically. */
+	spin_lock_irqsave(&d->tx_queue.lock, flags);
+
+	len = rfcomm_dlc_send_frag(d, skb);
+	if (len < 0 || !frag)
+		goto unlock;
+
+	for (; frag; frag = next) {
+		int ret;
+
+		next = frag->next;
+
+		ret = rfcomm_dlc_send_frag(d, frag);
+		if (ret < 0) {
+			dev_kfree_skb_irq(frag);
+			goto unlock;
+		}
+
+		len += ret;
+	}
+
+unlock:
+	spin_unlock_irqrestore(&d->tx_queue.lock, flags);
+
+	if (len > 0 && !test_bit(RFCOMM_TX_THROTTLED, &d->flags))
+		rfcomm_schedule();
+	return len;
+}
+
+void rfcomm_dlc_send_noerror(struct rfcomm_dlc *d, struct sk_buff *skb)
+{
+	int len = skb->len;
+
+	BT_DBG("dlc %p mtu %d len %d", d, d->mtu, len);
+
+	rfcomm_make_uih(skb, d->addr);
+	skb_queue_tail(&d->tx_queue, skb);
+
+	if (d->state == BT_CONNECTED &&
+	    !test_bit(RFCOMM_TX_THROTTLED, &d->flags))
+		rfcomm_schedule();
+}
+
+void __rfcomm_dlc_throttle(struct rfcomm_dlc *d)
+{
+	BT_DBG("dlc %p state %ld", d, d->state);
+
+	if (!d->cfc) {
+		d->v24_sig |= RFCOMM_V24_FC;
+		set_bit(RFCOMM_MSC_PENDING, &d->flags);
+	}
+	rfcomm_schedule();
+}
+
+void __rfcomm_dlc_unthrottle(struct rfcomm_dlc *d)
+{
+	BT_DBG("dlc %p state %ld", d, d->state);
+
+	if (!d->cfc) {
+		d->v24_sig &= ~RFCOMM_V24_FC;
+		set_bit(RFCOMM_MSC_PENDING, &d->flags);
+	}
+	rfcomm_schedule();
+}
+
+/*
+   Set/get modem status functions use _local_ status i.e. what we report
+   to the other side.
+   Remote status is provided by dlc->modem_status() callback.
+ */
+int rfcomm_dlc_set_modem_status(struct rfcomm_dlc *d, u8 v24_sig)
+{
+	BT_DBG("dlc %p state %ld v24_sig 0x%x",
+			d, d->state, v24_sig);
+
+	if (test_bit(RFCOMM_RX_THROTTLED, &d->flags))
+		v24_sig |= RFCOMM_V24_FC;
+	else
+		v24_sig &= ~RFCOMM_V24_FC;
+
+	d->v24_sig = v24_sig;
+
+	if (!test_and_set_bit(RFCOMM_MSC_PENDING, &d->flags))
+		rfcomm_schedule();
+
+	return 0;
+}
+
+int rfcomm_dlc_get_modem_status(struct rfcomm_dlc *d, u8 *v24_sig)
+{
+	BT_DBG("dlc %p state %ld v24_sig 0x%x",
+			d, d->state, d->v24_sig);
+
+	*v24_sig = d->v24_sig;
+	return 0;
+}
+
+/* ---- RFCOMM sessions ---- */
+static struct rfcomm_session *rfcomm_session_add(struct socket *sock, int state)
+{
+	struct rfcomm_session *s = kzalloc(sizeof(*s), GFP_KERNEL);
+
+	if (!s)
+		return NULL;
+
+	BT_DBG("session %p sock %p", s, sock);
+
+	timer_setup(&s->timer, rfcomm_session_timeout, 0);
+
+	INIT_LIST_HEAD(&s->dlcs);
+	s->state = state;
+	s->sock  = sock;
+
+	s->mtu = RFCOMM_DEFAULT_MTU;
+	s->cfc = disable_cfc ? RFCOMM_CFC_DISABLED : RFCOMM_CFC_UNKNOWN;
+
+	/* Do not increment module usage count for listening sessions.
+	 * Otherwise we won't be able to unload the module. */
+	if (state != BT_LISTEN)
+		if (!try_module_get(THIS_MODULE)) {
+			kfree(s);
+			return NULL;
+		}
+
+	list_add(&s->list, &session_list);
+
+	return s;
+}
+
+static struct rfcomm_session *rfcomm_session_del(struct rfcomm_session *s)
+{
+	int state = s->state;
+
+	BT_DBG("session %p state %ld", s, s->state);
+
+	list_del(&s->list);
+
+	rfcomm_session_clear_timer(s);
+	sock_release(s->sock);
+	kfree(s);
+
+	if (state != BT_LISTEN)
+		module_put(THIS_MODULE);
+
+	return NULL;
+}
+
+static struct rfcomm_session *rfcomm_session_get(bdaddr_t *src, bdaddr_t *dst)
+{
+	struct rfcomm_session *s, *n;
+	struct l2cap_chan *chan;
+	list_for_each_entry_safe(s, n, &session_list, list) {
+		chan = l2cap_pi(s->sock->sk)->chan;
+
+		if ((!bacmp(src, BDADDR_ANY) || !bacmp(&chan->src, src)) &&
+		    !bacmp(&chan->dst, dst))
+			return s;
+	}
+	return NULL;
+}
+
+static struct rfcomm_session *rfcomm_session_close(struct rfcomm_session *s,
+						   int err)
+{
+	struct rfcomm_dlc *d, *n;
+
+	s->state = BT_CLOSED;
+
+	BT_DBG("session %p state %ld err %d", s, s->state, err);
+
+	/* Close all dlcs */
+	list_for_each_entry_safe(d, n, &s->dlcs, list) {
+		d->state = BT_CLOSED;
+		__rfcomm_dlc_close(d, err);
+	}
+
+	rfcomm_session_clear_timer(s);
+	return rfcomm_session_del(s);
+}
+
+static struct rfcomm_session *rfcomm_session_create(bdaddr_t *src,
+							bdaddr_t *dst,
+							u8 sec_level,
+							int *err)
+{
+	struct rfcomm_session *s = NULL;
+	struct sockaddr_l2 addr;
+	struct socket *sock;
+	struct sock *sk;
+
+	BT_DBG("%pMR -> %pMR", src, dst);
+
+	*err = rfcomm_l2sock_create(&sock);
+	if (*err < 0)
+		return NULL;
+
+	bacpy(&addr.l2_bdaddr, src);
+	addr.l2_family = AF_BLUETOOTH;
+	addr.l2_psm    = 0;
+	addr.l2_cid    = 0;
+	addr.l2_bdaddr_type = BDADDR_BREDR;
+	*err = kernel_bind(sock, (struct sockaddr *) &addr, sizeof(addr));
+	if (*err < 0)
+		goto failed;
+
+	/* Set L2CAP options */
+	sk = sock->sk;
+	lock_sock(sk);
+	/* Set MTU to 0 so L2CAP can auto select the MTU */
+	l2cap_pi(sk)->chan->imtu = 0;
+	l2cap_pi(sk)->chan->sec_level = sec_level;
+	if (l2cap_ertm)
+		l2cap_pi(sk)->chan->mode = L2CAP_MODE_ERTM;
+	release_sock(sk);
+
+	s = rfcomm_session_add(sock, BT_BOUND);
+	if (!s) {
+		*err = -ENOMEM;
+		goto failed;
+	}
+
+	s->initiator = 1;
+
+	bacpy(&addr.l2_bdaddr, dst);
+	addr.l2_family = AF_BLUETOOTH;
+	addr.l2_psm    = cpu_to_le16(L2CAP_PSM_RFCOMM);
+	addr.l2_cid    = 0;
+	addr.l2_bdaddr_type = BDADDR_BREDR;
+	*err = kernel_connect(sock, (struct sockaddr *) &addr, sizeof(addr), O_NONBLOCK);
+	if (*err == 0 || *err == -EINPROGRESS)
+		return s;
+
+	return rfcomm_session_del(s);
+
+failed:
+	sock_release(sock);
+	return NULL;
+}
+
+void rfcomm_session_getaddr(struct rfcomm_session *s, bdaddr_t *src, bdaddr_t *dst)
+{
+	struct l2cap_chan *chan = l2cap_pi(s->sock->sk)->chan;
+	if (src)
+		bacpy(src, &chan->src);
+	if (dst)
+		bacpy(dst, &chan->dst);
+}
+
+/* ---- RFCOMM frame sending ---- */
+static int rfcomm_send_frame(struct rfcomm_session *s, u8 *data, int len)
+{
+	struct kvec iv = { data, len };
+	struct msghdr msg;
+
+	BT_DBG("session %p len %d", s, len);
+
+	memset(&msg, 0, sizeof(msg));
+
+	return kernel_sendmsg(s->sock, &msg, &iv, 1, len);
+}
+
+static int rfcomm_send_cmd(struct rfcomm_session *s, struct rfcomm_cmd *cmd)
+{
+	BT_DBG("%p cmd %u", s, cmd->ctrl);
+
+	return rfcomm_send_frame(s, (void *) cmd, sizeof(*cmd));
+}
+
+static int rfcomm_send_sabm(struct rfcomm_session *s, u8 dlci)
+{
+	struct rfcomm_cmd cmd;
+
+	BT_DBG("%p dlci %d", s, dlci);
+
+	cmd.addr = __addr(s->initiator, dlci);
+	cmd.ctrl = __ctrl(RFCOMM_SABM, 1);
+	cmd.len  = __len8(0);
+	cmd.fcs  = __fcs2((u8 *) &cmd);
+
+	return rfcomm_send_cmd(s, &cmd);
+}
+
+static int rfcomm_send_ua(struct rfcomm_session *s, u8 dlci)
+{
+	struct rfcomm_cmd cmd;
+
+	BT_DBG("%p dlci %d", s, dlci);
+
+	cmd.addr = __addr(!s->initiator, dlci);
+	cmd.ctrl = __ctrl(RFCOMM_UA, 1);
+	cmd.len  = __len8(0);
+	cmd.fcs  = __fcs2((u8 *) &cmd);
+
+	return rfcomm_send_cmd(s, &cmd);
+}
+
+static int rfcomm_send_disc(struct rfcomm_session *s, u8 dlci)
+{
+	struct rfcomm_cmd cmd;
+
+	BT_DBG("%p dlci %d", s, dlci);
+
+	cmd.addr = __addr(s->initiator, dlci);
+	cmd.ctrl = __ctrl(RFCOMM_DISC, 1);
+	cmd.len  = __len8(0);
+	cmd.fcs  = __fcs2((u8 *) &cmd);
+
+	return rfcomm_send_cmd(s, &cmd);
+}
+
+static int rfcomm_queue_disc(struct rfcomm_dlc *d)
+{
+	struct rfcomm_cmd *cmd;
+	struct sk_buff *skb;
+
+	BT_DBG("dlc %p dlci %d", d, d->dlci);
+
+	skb = alloc_skb(sizeof(*cmd), GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	cmd = __skb_put(skb, sizeof(*cmd));
+	cmd->addr = d->addr;
+	cmd->ctrl = __ctrl(RFCOMM_DISC, 1);
+	cmd->len  = __len8(0);
+	cmd->fcs  = __fcs2((u8 *) cmd);
+
+	skb_queue_tail(&d->tx_queue, skb);
+	rfcomm_schedule();
+	return 0;
+}
+
+static int rfcomm_send_dm(struct rfcomm_session *s, u8 dlci)
+{
+	struct rfcomm_cmd cmd;
+
+	BT_DBG("%p dlci %d", s, dlci);
+
+	cmd.addr = __addr(!s->initiator, dlci);
+	cmd.ctrl = __ctrl(RFCOMM_DM, 1);
+	cmd.len  = __len8(0);
+	cmd.fcs  = __fcs2((u8 *) &cmd);
+
+	return rfcomm_send_cmd(s, &cmd);
+}
+
+static int rfcomm_send_nsc(struct rfcomm_session *s, int cr, u8 type)
+{
+	struct rfcomm_hdr *hdr;
+	struct rfcomm_mcc *mcc;
+	u8 buf[16], *ptr = buf;
+
+	BT_DBG("%p cr %d type %d", s, cr, type);
+
+	hdr = (void *) ptr; ptr += sizeof(*hdr);
+	hdr->addr = __addr(s->initiator, 0);
+	hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
+	hdr->len  = __len8(sizeof(*mcc) + 1);
+
+	mcc = (void *) ptr; ptr += sizeof(*mcc);
+	mcc->type = __mcc_type(0, RFCOMM_NSC);
+	mcc->len  = __len8(1);
+
+	/* Type that we didn't like */
+	*ptr = __mcc_type(cr, type); ptr++;
+
+	*ptr = __fcs(buf); ptr++;
+
+	return rfcomm_send_frame(s, buf, ptr - buf);
+}
+
+static int rfcomm_send_pn(struct rfcomm_session *s, int cr, struct rfcomm_dlc *d)
+{
+	struct rfcomm_hdr *hdr;
+	struct rfcomm_mcc *mcc;
+	struct rfcomm_pn  *pn;
+	u8 buf[16], *ptr = buf;
+
+	BT_DBG("%p cr %d dlci %d mtu %d", s, cr, d->dlci, d->mtu);
+
+	hdr = (void *) ptr; ptr += sizeof(*hdr);
+	hdr->addr = __addr(s->initiator, 0);
+	hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
+	hdr->len  = __len8(sizeof(*mcc) + sizeof(*pn));
+
+	mcc = (void *) ptr; ptr += sizeof(*mcc);
+	mcc->type = __mcc_type(cr, RFCOMM_PN);
+	mcc->len  = __len8(sizeof(*pn));
+
+	pn = (void *) ptr; ptr += sizeof(*pn);
+	pn->dlci        = d->dlci;
+	pn->priority    = d->priority;
+	pn->ack_timer   = 0;
+	pn->max_retrans = 0;
+
+	if (s->cfc) {
+		pn->flow_ctrl = cr ? 0xf0 : 0xe0;
+		pn->credits = RFCOMM_DEFAULT_CREDITS;
+	} else {
+		pn->flow_ctrl = 0;
+		pn->credits   = 0;
+	}
+
+	if (cr && channel_mtu >= 0)
+		pn->mtu = cpu_to_le16(channel_mtu);
+	else
+		pn->mtu = cpu_to_le16(d->mtu);
+
+	*ptr = __fcs(buf); ptr++;
+
+	return rfcomm_send_frame(s, buf, ptr - buf);
+}
+
+int rfcomm_send_rpn(struct rfcomm_session *s, int cr, u8 dlci,
+			u8 bit_rate, u8 data_bits, u8 stop_bits,
+			u8 parity, u8 flow_ctrl_settings,
+			u8 xon_char, u8 xoff_char, u16 param_mask)
+{
+	struct rfcomm_hdr *hdr;
+	struct rfcomm_mcc *mcc;
+	struct rfcomm_rpn *rpn;
+	u8 buf[16], *ptr = buf;
+
+	BT_DBG("%p cr %d dlci %d bit_r 0x%x data_b 0x%x stop_b 0x%x parity 0x%x"
+			" flwc_s 0x%x xon_c 0x%x xoff_c 0x%x p_mask 0x%x",
+		s, cr, dlci, bit_rate, data_bits, stop_bits, parity,
+		flow_ctrl_settings, xon_char, xoff_char, param_mask);
+
+	hdr = (void *) ptr; ptr += sizeof(*hdr);
+	hdr->addr = __addr(s->initiator, 0);
+	hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
+	hdr->len  = __len8(sizeof(*mcc) + sizeof(*rpn));
+
+	mcc = (void *) ptr; ptr += sizeof(*mcc);
+	mcc->type = __mcc_type(cr, RFCOMM_RPN);
+	mcc->len  = __len8(sizeof(*rpn));
+
+	rpn = (void *) ptr; ptr += sizeof(*rpn);
+	rpn->dlci          = __addr(1, dlci);
+	rpn->bit_rate      = bit_rate;
+	rpn->line_settings = __rpn_line_settings(data_bits, stop_bits, parity);
+	rpn->flow_ctrl     = flow_ctrl_settings;
+	rpn->xon_char      = xon_char;
+	rpn->xoff_char     = xoff_char;
+	rpn->param_mask    = cpu_to_le16(param_mask);
+
+	*ptr = __fcs(buf); ptr++;
+
+	return rfcomm_send_frame(s, buf, ptr - buf);
+}
+
+static int rfcomm_send_rls(struct rfcomm_session *s, int cr, u8 dlci, u8 status)
+{
+	struct rfcomm_hdr *hdr;
+	struct rfcomm_mcc *mcc;
+	struct rfcomm_rls *rls;
+	u8 buf[16], *ptr = buf;
+
+	BT_DBG("%p cr %d status 0x%x", s, cr, status);
+
+	hdr = (void *) ptr; ptr += sizeof(*hdr);
+	hdr->addr = __addr(s->initiator, 0);
+	hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
+	hdr->len  = __len8(sizeof(*mcc) + sizeof(*rls));
+
+	mcc = (void *) ptr; ptr += sizeof(*mcc);
+	mcc->type = __mcc_type(cr, RFCOMM_RLS);
+	mcc->len  = __len8(sizeof(*rls));
+
+	rls = (void *) ptr; ptr += sizeof(*rls);
+	rls->dlci   = __addr(1, dlci);
+	rls->status = status;
+
+	*ptr = __fcs(buf); ptr++;
+
+	return rfcomm_send_frame(s, buf, ptr - buf);
+}
+
+static int rfcomm_send_msc(struct rfcomm_session *s, int cr, u8 dlci, u8 v24_sig)
+{
+	struct rfcomm_hdr *hdr;
+	struct rfcomm_mcc *mcc;
+	struct rfcomm_msc *msc;
+	u8 buf[16], *ptr = buf;
+
+	BT_DBG("%p cr %d v24 0x%x", s, cr, v24_sig);
+
+	hdr = (void *) ptr; ptr += sizeof(*hdr);
+	hdr->addr = __addr(s->initiator, 0);
+	hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
+	hdr->len  = __len8(sizeof(*mcc) + sizeof(*msc));
+
+	mcc = (void *) ptr; ptr += sizeof(*mcc);
+	mcc->type = __mcc_type(cr, RFCOMM_MSC);
+	mcc->len  = __len8(sizeof(*msc));
+
+	msc = (void *) ptr; ptr += sizeof(*msc);
+	msc->dlci    = __addr(1, dlci);
+	msc->v24_sig = v24_sig | 0x01;
+
+	*ptr = __fcs(buf); ptr++;
+
+	return rfcomm_send_frame(s, buf, ptr - buf);
+}
+
+static int rfcomm_send_fcoff(struct rfcomm_session *s, int cr)
+{
+	struct rfcomm_hdr *hdr;
+	struct rfcomm_mcc *mcc;
+	u8 buf[16], *ptr = buf;
+
+	BT_DBG("%p cr %d", s, cr);
+
+	hdr = (void *) ptr; ptr += sizeof(*hdr);
+	hdr->addr = __addr(s->initiator, 0);
+	hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
+	hdr->len  = __len8(sizeof(*mcc));
+
+	mcc = (void *) ptr; ptr += sizeof(*mcc);
+	mcc->type = __mcc_type(cr, RFCOMM_FCOFF);
+	mcc->len  = __len8(0);
+
+	*ptr = __fcs(buf); ptr++;
+
+	return rfcomm_send_frame(s, buf, ptr - buf);
+}
+
+static int rfcomm_send_fcon(struct rfcomm_session *s, int cr)
+{
+	struct rfcomm_hdr *hdr;
+	struct rfcomm_mcc *mcc;
+	u8 buf[16], *ptr = buf;
+
+	BT_DBG("%p cr %d", s, cr);
+
+	hdr = (void *) ptr; ptr += sizeof(*hdr);
+	hdr->addr = __addr(s->initiator, 0);
+	hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
+	hdr->len  = __len8(sizeof(*mcc));
+
+	mcc = (void *) ptr; ptr += sizeof(*mcc);
+	mcc->type = __mcc_type(cr, RFCOMM_FCON);
+	mcc->len  = __len8(0);
+
+	*ptr = __fcs(buf); ptr++;
+
+	return rfcomm_send_frame(s, buf, ptr - buf);
+}
+
+static int rfcomm_send_test(struct rfcomm_session *s, int cr, u8 *pattern, int len)
+{
+	struct socket *sock = s->sock;
+	struct kvec iv[3];
+	struct msghdr msg;
+	unsigned char hdr[5], crc[1];
+
+	if (len > 125)
+		return -EINVAL;
+
+	BT_DBG("%p cr %d", s, cr);
+
+	hdr[0] = __addr(s->initiator, 0);
+	hdr[1] = __ctrl(RFCOMM_UIH, 0);
+	hdr[2] = 0x01 | ((len + 2) << 1);
+	hdr[3] = 0x01 | ((cr & 0x01) << 1) | (RFCOMM_TEST << 2);
+	hdr[4] = 0x01 | (len << 1);
+
+	crc[0] = __fcs(hdr);
+
+	iv[0].iov_base = hdr;
+	iv[0].iov_len  = 5;
+	iv[1].iov_base = pattern;
+	iv[1].iov_len  = len;
+	iv[2].iov_base = crc;
+	iv[2].iov_len  = 1;
+
+	memset(&msg, 0, sizeof(msg));
+
+	return kernel_sendmsg(sock, &msg, iv, 3, 6 + len);
+}
+
+static int rfcomm_send_credits(struct rfcomm_session *s, u8 addr, u8 credits)
+{
+	struct rfcomm_hdr *hdr;
+	u8 buf[16], *ptr = buf;
+
+	BT_DBG("%p addr %d credits %d", s, addr, credits);
+
+	hdr = (void *) ptr; ptr += sizeof(*hdr);
+	hdr->addr = addr;
+	hdr->ctrl = __ctrl(RFCOMM_UIH, 1);
+	hdr->len  = __len8(0);
+
+	*ptr = credits; ptr++;
+
+	*ptr = __fcs(buf); ptr++;
+
+	return rfcomm_send_frame(s, buf, ptr - buf);
+}
+
+static void rfcomm_make_uih(struct sk_buff *skb, u8 addr)
+{
+	struct rfcomm_hdr *hdr;
+	int len = skb->len;
+	u8 *crc;
+
+	if (len > 127) {
+		hdr = skb_push(skb, 4);
+		put_unaligned(cpu_to_le16(__len16(len)), (__le16 *) &hdr->len);
+	} else {
+		hdr = skb_push(skb, 3);
+		hdr->len = __len8(len);
+	}
+	hdr->addr = addr;
+	hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
+
+	crc = skb_put(skb, 1);
+	*crc = __fcs((void *) hdr);
+}
+
+/* ---- RFCOMM frame reception ---- */
+static struct rfcomm_session *rfcomm_recv_ua(struct rfcomm_session *s, u8 dlci)
+{
+	BT_DBG("session %p state %ld dlci %d", s, s->state, dlci);
+
+	if (dlci) {
+		/* Data channel */
+		struct rfcomm_dlc *d = rfcomm_dlc_get(s, dlci);
+		if (!d) {
+			rfcomm_send_dm(s, dlci);
+			return s;
+		}
+
+		switch (d->state) {
+		case BT_CONNECT:
+			rfcomm_dlc_clear_timer(d);
+
+			rfcomm_dlc_lock(d);
+			d->state = BT_CONNECTED;
+			d->state_change(d, 0);
+			rfcomm_dlc_unlock(d);
+
+			rfcomm_send_msc(s, 1, dlci, d->v24_sig);
+			break;
+
+		case BT_DISCONN:
+			d->state = BT_CLOSED;
+			__rfcomm_dlc_close(d, 0);
+
+			if (list_empty(&s->dlcs)) {
+				s->state = BT_DISCONN;
+				rfcomm_send_disc(s, 0);
+				rfcomm_session_clear_timer(s);
+			}
+
+			break;
+		}
+	} else {
+		/* Control channel */
+		switch (s->state) {
+		case BT_CONNECT:
+			s->state = BT_CONNECTED;
+			rfcomm_process_connect(s);
+			break;
+
+		case BT_DISCONN:
+			s = rfcomm_session_close(s, ECONNRESET);
+			break;
+		}
+	}
+	return s;
+}
+
+static struct rfcomm_session *rfcomm_recv_dm(struct rfcomm_session *s, u8 dlci)
+{
+	int err = 0;
+
+	BT_DBG("session %p state %ld dlci %d", s, s->state, dlci);
+
+	if (dlci) {
+		/* Data DLC */
+		struct rfcomm_dlc *d = rfcomm_dlc_get(s, dlci);
+		if (d) {
+			if (d->state == BT_CONNECT || d->state == BT_CONFIG)
+				err = ECONNREFUSED;
+			else
+				err = ECONNRESET;
+
+			d->state = BT_CLOSED;
+			__rfcomm_dlc_close(d, err);
+		}
+	} else {
+		if (s->state == BT_CONNECT)
+			err = ECONNREFUSED;
+		else
+			err = ECONNRESET;
+
+		s = rfcomm_session_close(s, err);
+	}
+	return s;
+}
+
+static struct rfcomm_session *rfcomm_recv_disc(struct rfcomm_session *s,
+					       u8 dlci)
+{
+	int err = 0;
+
+	BT_DBG("session %p state %ld dlci %d", s, s->state, dlci);
+
+	if (dlci) {
+		struct rfcomm_dlc *d = rfcomm_dlc_get(s, dlci);
+		if (d) {
+			rfcomm_send_ua(s, dlci);
+
+			if (d->state == BT_CONNECT || d->state == BT_CONFIG)
+				err = ECONNREFUSED;
+			else
+				err = ECONNRESET;
+
+			d->state = BT_CLOSED;
+			__rfcomm_dlc_close(d, err);
+		} else
+			rfcomm_send_dm(s, dlci);
+
+	} else {
+		rfcomm_send_ua(s, 0);
+
+		if (s->state == BT_CONNECT)
+			err = ECONNREFUSED;
+		else
+			err = ECONNRESET;
+
+		s = rfcomm_session_close(s, err);
+	}
+	return s;
+}
+
+void rfcomm_dlc_accept(struct rfcomm_dlc *d)
+{
+	struct sock *sk = d->session->sock->sk;
+	struct l2cap_conn *conn = l2cap_pi(sk)->chan->conn;
+
+	BT_DBG("dlc %p", d);
+
+	rfcomm_send_ua(d->session, d->dlci);
+
+	rfcomm_dlc_clear_timer(d);
+
+	rfcomm_dlc_lock(d);
+	d->state = BT_CONNECTED;
+	d->state_change(d, 0);
+	rfcomm_dlc_unlock(d);
+
+	if (d->role_switch)
+		hci_conn_switch_role(conn->hcon, 0x00);
+
+	rfcomm_send_msc(d->session, 1, d->dlci, d->v24_sig);
+}
+
+static void rfcomm_check_accept(struct rfcomm_dlc *d)
+{
+	if (rfcomm_check_security(d)) {
+		if (d->defer_setup) {
+			set_bit(RFCOMM_DEFER_SETUP, &d->flags);
+			rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
+
+			rfcomm_dlc_lock(d);
+			d->state = BT_CONNECT2;
+			d->state_change(d, 0);
+			rfcomm_dlc_unlock(d);
+		} else
+			rfcomm_dlc_accept(d);
+	} else {
+		set_bit(RFCOMM_AUTH_PENDING, &d->flags);
+		rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
+	}
+}
+
+static int rfcomm_recv_sabm(struct rfcomm_session *s, u8 dlci)
+{
+	struct rfcomm_dlc *d;
+	u8 channel;
+
+	BT_DBG("session %p state %ld dlci %d", s, s->state, dlci);
+
+	if (!dlci) {
+		rfcomm_send_ua(s, 0);
+
+		if (s->state == BT_OPEN) {
+			s->state = BT_CONNECTED;
+			rfcomm_process_connect(s);
+		}
+		return 0;
+	}
+
+	/* Check if DLC exists */
+	d = rfcomm_dlc_get(s, dlci);
+	if (d) {
+		if (d->state == BT_OPEN) {
+			/* DLC was previously opened by PN request */
+			rfcomm_check_accept(d);
+		}
+		return 0;
+	}
+
+	/* Notify socket layer about incoming connection */
+	channel = __srv_channel(dlci);
+	if (rfcomm_connect_ind(s, channel, &d)) {
+		d->dlci = dlci;
+		d->addr = __addr(s->initiator, dlci);
+		rfcomm_dlc_link(s, d);
+
+		rfcomm_check_accept(d);
+	} else {
+		rfcomm_send_dm(s, dlci);
+	}
+
+	return 0;
+}
+
+static int rfcomm_apply_pn(struct rfcomm_dlc *d, int cr, struct rfcomm_pn *pn)
+{
+	struct rfcomm_session *s = d->session;
+
+	BT_DBG("dlc %p state %ld dlci %d mtu %d fc 0x%x credits %d",
+			d, d->state, d->dlci, pn->mtu, pn->flow_ctrl, pn->credits);
+
+	if ((pn->flow_ctrl == 0xf0 && s->cfc != RFCOMM_CFC_DISABLED) ||
+						pn->flow_ctrl == 0xe0) {
+		d->cfc = RFCOMM_CFC_ENABLED;
+		d->tx_credits = pn->credits;
+	} else {
+		d->cfc = RFCOMM_CFC_DISABLED;
+		set_bit(RFCOMM_TX_THROTTLED, &d->flags);
+	}
+
+	if (s->cfc == RFCOMM_CFC_UNKNOWN)
+		s->cfc = d->cfc;
+
+	d->priority = pn->priority;
+
+	d->mtu = __le16_to_cpu(pn->mtu);
+
+	if (cr && d->mtu > s->mtu)
+		d->mtu = s->mtu;
+
+	return 0;
+}
+
+static int rfcomm_recv_pn(struct rfcomm_session *s, int cr, struct sk_buff *skb)
+{
+	struct rfcomm_pn *pn = (void *) skb->data;
+	struct rfcomm_dlc *d;
+	u8 dlci = pn->dlci;
+
+	BT_DBG("session %p state %ld dlci %d", s, s->state, dlci);
+
+	if (!dlci)
+		return 0;
+
+	d = rfcomm_dlc_get(s, dlci);
+	if (d) {
+		if (cr) {
+			/* PN request */
+			rfcomm_apply_pn(d, cr, pn);
+			rfcomm_send_pn(s, 0, d);
+		} else {
+			/* PN response */
+			switch (d->state) {
+			case BT_CONFIG:
+				rfcomm_apply_pn(d, cr, pn);
+
+				d->state = BT_CONNECT;
+				rfcomm_send_sabm(s, d->dlci);
+				break;
+			}
+		}
+	} else {
+		u8 channel = __srv_channel(dlci);
+
+		if (!cr)
+			return 0;
+
+		/* PN request for non existing DLC.
+		 * Assume incoming connection. */
+		if (rfcomm_connect_ind(s, channel, &d)) {
+			d->dlci = dlci;
+			d->addr = __addr(s->initiator, dlci);
+			rfcomm_dlc_link(s, d);
+
+			rfcomm_apply_pn(d, cr, pn);
+
+			d->state = BT_OPEN;
+			rfcomm_send_pn(s, 0, d);
+		} else {
+			rfcomm_send_dm(s, dlci);
+		}
+	}
+	return 0;
+}
+
+static int rfcomm_recv_rpn(struct rfcomm_session *s, int cr, int len, struct sk_buff *skb)
+{
+	struct rfcomm_rpn *rpn = (void *) skb->data;
+	u8 dlci = __get_dlci(rpn->dlci);
+
+	u8 bit_rate  = 0;
+	u8 data_bits = 0;
+	u8 stop_bits = 0;
+	u8 parity    = 0;
+	u8 flow_ctrl = 0;
+	u8 xon_char  = 0;
+	u8 xoff_char = 0;
+	u16 rpn_mask = RFCOMM_RPN_PM_ALL;
+
+	BT_DBG("dlci %d cr %d len 0x%x bitr 0x%x line 0x%x flow 0x%x xonc 0x%x xoffc 0x%x pm 0x%x",
+		dlci, cr, len, rpn->bit_rate, rpn->line_settings, rpn->flow_ctrl,
+		rpn->xon_char, rpn->xoff_char, rpn->param_mask);
+
+	if (!cr)
+		return 0;
+
+	if (len == 1) {
+		/* This is a request, return default (according to ETSI TS 07.10) settings */
+		bit_rate  = RFCOMM_RPN_BR_9600;
+		data_bits = RFCOMM_RPN_DATA_8;
+		stop_bits = RFCOMM_RPN_STOP_1;
+		parity    = RFCOMM_RPN_PARITY_NONE;
+		flow_ctrl = RFCOMM_RPN_FLOW_NONE;
+		xon_char  = RFCOMM_RPN_XON_CHAR;
+		xoff_char = RFCOMM_RPN_XOFF_CHAR;
+		goto rpn_out;
+	}
+
+	/* Check for sane values, ignore/accept bit_rate, 8 bits, 1 stop bit,
+	 * no parity, no flow control lines, normal XON/XOFF chars */
+
+	if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_BITRATE)) {
+		bit_rate = rpn->bit_rate;
+		if (bit_rate > RFCOMM_RPN_BR_230400) {
+			BT_DBG("RPN bit rate mismatch 0x%x", bit_rate);
+			bit_rate = RFCOMM_RPN_BR_9600;
+			rpn_mask ^= RFCOMM_RPN_PM_BITRATE;
+		}
+	}
+
+	if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_DATA)) {
+		data_bits = __get_rpn_data_bits(rpn->line_settings);
+		if (data_bits != RFCOMM_RPN_DATA_8) {
+			BT_DBG("RPN data bits mismatch 0x%x", data_bits);
+			data_bits = RFCOMM_RPN_DATA_8;
+			rpn_mask ^= RFCOMM_RPN_PM_DATA;
+		}
+	}
+
+	if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_STOP)) {
+		stop_bits = __get_rpn_stop_bits(rpn->line_settings);
+		if (stop_bits != RFCOMM_RPN_STOP_1) {
+			BT_DBG("RPN stop bits mismatch 0x%x", stop_bits);
+			stop_bits = RFCOMM_RPN_STOP_1;
+			rpn_mask ^= RFCOMM_RPN_PM_STOP;
+		}
+	}
+
+	if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_PARITY)) {
+		parity = __get_rpn_parity(rpn->line_settings);
+		if (parity != RFCOMM_RPN_PARITY_NONE) {
+			BT_DBG("RPN parity mismatch 0x%x", parity);
+			parity = RFCOMM_RPN_PARITY_NONE;
+			rpn_mask ^= RFCOMM_RPN_PM_PARITY;
+		}
+	}
+
+	if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_FLOW)) {
+		flow_ctrl = rpn->flow_ctrl;
+		if (flow_ctrl != RFCOMM_RPN_FLOW_NONE) {
+			BT_DBG("RPN flow ctrl mismatch 0x%x", flow_ctrl);
+			flow_ctrl = RFCOMM_RPN_FLOW_NONE;
+			rpn_mask ^= RFCOMM_RPN_PM_FLOW;
+		}
+	}
+
+	if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_XON)) {
+		xon_char = rpn->xon_char;
+		if (xon_char != RFCOMM_RPN_XON_CHAR) {
+			BT_DBG("RPN XON char mismatch 0x%x", xon_char);
+			xon_char = RFCOMM_RPN_XON_CHAR;
+			rpn_mask ^= RFCOMM_RPN_PM_XON;
+		}
+	}
+
+	if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_XOFF)) {
+		xoff_char = rpn->xoff_char;
+		if (xoff_char != RFCOMM_RPN_XOFF_CHAR) {
+			BT_DBG("RPN XOFF char mismatch 0x%x", xoff_char);
+			xoff_char = RFCOMM_RPN_XOFF_CHAR;
+			rpn_mask ^= RFCOMM_RPN_PM_XOFF;
+		}
+	}
+
+rpn_out:
+	rfcomm_send_rpn(s, 0, dlci, bit_rate, data_bits, stop_bits,
+			parity, flow_ctrl, xon_char, xoff_char, rpn_mask);
+
+	return 0;
+}
+
+static int rfcomm_recv_rls(struct rfcomm_session *s, int cr, struct sk_buff *skb)
+{
+	struct rfcomm_rls *rls = (void *) skb->data;
+	u8 dlci = __get_dlci(rls->dlci);
+
+	BT_DBG("dlci %d cr %d status 0x%x", dlci, cr, rls->status);
+
+	if (!cr)
+		return 0;
+
+	/* We should probably do something with this information here. But
+	 * for now it's sufficient just to reply -- Bluetooth 1.1 says it's
+	 * mandatory to recognise and respond to RLS */
+
+	rfcomm_send_rls(s, 0, dlci, rls->status);
+
+	return 0;
+}
+
+static int rfcomm_recv_msc(struct rfcomm_session *s, int cr, struct sk_buff *skb)
+{
+	struct rfcomm_msc *msc = (void *) skb->data;
+	struct rfcomm_dlc *d;
+	u8 dlci = __get_dlci(msc->dlci);
+
+	BT_DBG("dlci %d cr %d v24 0x%x", dlci, cr, msc->v24_sig);
+
+	d = rfcomm_dlc_get(s, dlci);
+	if (!d)
+		return 0;
+
+	if (cr) {
+		if (msc->v24_sig & RFCOMM_V24_FC && !d->cfc)
+			set_bit(RFCOMM_TX_THROTTLED, &d->flags);
+		else
+			clear_bit(RFCOMM_TX_THROTTLED, &d->flags);
+
+		rfcomm_dlc_lock(d);
+
+		d->remote_v24_sig = msc->v24_sig;
+
+		if (d->modem_status)
+			d->modem_status(d, msc->v24_sig);
+
+		rfcomm_dlc_unlock(d);
+
+		rfcomm_send_msc(s, 0, dlci, msc->v24_sig);
+
+		d->mscex |= RFCOMM_MSCEX_RX;
+	} else
+		d->mscex |= RFCOMM_MSCEX_TX;
+
+	return 0;
+}
+
+static int rfcomm_recv_mcc(struct rfcomm_session *s, struct sk_buff *skb)
+{
+	struct rfcomm_mcc *mcc = (void *) skb->data;
+	u8 type, cr, len;
+
+	cr   = __test_cr(mcc->type);
+	type = __get_mcc_type(mcc->type);
+	len  = __get_mcc_len(mcc->len);
+
+	BT_DBG("%p type 0x%x cr %d", s, type, cr);
+
+	skb_pull(skb, 2);
+
+	switch (type) {
+	case RFCOMM_PN:
+		rfcomm_recv_pn(s, cr, skb);
+		break;
+
+	case RFCOMM_RPN:
+		rfcomm_recv_rpn(s, cr, len, skb);
+		break;
+
+	case RFCOMM_RLS:
+		rfcomm_recv_rls(s, cr, skb);
+		break;
+
+	case RFCOMM_MSC:
+		rfcomm_recv_msc(s, cr, skb);
+		break;
+
+	case RFCOMM_FCOFF:
+		if (cr) {
+			set_bit(RFCOMM_TX_THROTTLED, &s->flags);
+			rfcomm_send_fcoff(s, 0);
+		}
+		break;
+
+	case RFCOMM_FCON:
+		if (cr) {
+			clear_bit(RFCOMM_TX_THROTTLED, &s->flags);
+			rfcomm_send_fcon(s, 0);
+		}
+		break;
+
+	case RFCOMM_TEST:
+		if (cr)
+			rfcomm_send_test(s, 0, skb->data, skb->len);
+		break;
+
+	case RFCOMM_NSC:
+		break;
+
+	default:
+		BT_ERR("Unknown control type 0x%02x", type);
+		rfcomm_send_nsc(s, cr, type);
+		break;
+	}
+	return 0;
+}
+
+static int rfcomm_recv_data(struct rfcomm_session *s, u8 dlci, int pf, struct sk_buff *skb)
+{
+	struct rfcomm_dlc *d;
+
+	BT_DBG("session %p state %ld dlci %d pf %d", s, s->state, dlci, pf);
+
+	d = rfcomm_dlc_get(s, dlci);
+	if (!d) {
+		rfcomm_send_dm(s, dlci);
+		goto drop;
+	}
+
+	if (pf && d->cfc) {
+		u8 credits = *(u8 *) skb->data; skb_pull(skb, 1);
+
+		d->tx_credits += credits;
+		if (d->tx_credits)
+			clear_bit(RFCOMM_TX_THROTTLED, &d->flags);
+	}
+
+	if (skb->len && d->state == BT_CONNECTED) {
+		rfcomm_dlc_lock(d);
+		d->rx_credits--;
+		d->data_ready(d, skb);
+		rfcomm_dlc_unlock(d);
+		return 0;
+	}
+
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+
+static struct rfcomm_session *rfcomm_recv_frame(struct rfcomm_session *s,
+						struct sk_buff *skb)
+{
+	struct rfcomm_hdr *hdr = (void *) skb->data;
+	u8 type, dlci, fcs;
+
+	if (!s) {
+		/* no session, so free socket data */
+		kfree_skb(skb);
+		return s;
+	}
+
+	dlci = __get_dlci(hdr->addr);
+	type = __get_type(hdr->ctrl);
+
+	/* Trim FCS */
+	skb->len--; skb->tail--;
+	fcs = *(u8 *)skb_tail_pointer(skb);
+
+	if (__check_fcs(skb->data, type, fcs)) {
+		BT_ERR("bad checksum in packet");
+		kfree_skb(skb);
+		return s;
+	}
+
+	if (__test_ea(hdr->len))
+		skb_pull(skb, 3);
+	else
+		skb_pull(skb, 4);
+
+	switch (type) {
+	case RFCOMM_SABM:
+		if (__test_pf(hdr->ctrl))
+			rfcomm_recv_sabm(s, dlci);
+		break;
+
+	case RFCOMM_DISC:
+		if (__test_pf(hdr->ctrl))
+			s = rfcomm_recv_disc(s, dlci);
+		break;
+
+	case RFCOMM_UA:
+		if (__test_pf(hdr->ctrl))
+			s = rfcomm_recv_ua(s, dlci);
+		break;
+
+	case RFCOMM_DM:
+		s = rfcomm_recv_dm(s, dlci);
+		break;
+
+	case RFCOMM_UIH:
+		if (dlci) {
+			rfcomm_recv_data(s, dlci, __test_pf(hdr->ctrl), skb);
+			return s;
+		}
+		rfcomm_recv_mcc(s, skb);
+		break;
+
+	default:
+		BT_ERR("Unknown packet type 0x%02x", type);
+		break;
+	}
+	kfree_skb(skb);
+	return s;
+}
+
+/* ---- Connection and data processing ---- */
+
+static void rfcomm_process_connect(struct rfcomm_session *s)
+{
+	struct rfcomm_dlc *d, *n;
+
+	BT_DBG("session %p state %ld", s, s->state);
+
+	list_for_each_entry_safe(d, n, &s->dlcs, list) {
+		if (d->state == BT_CONFIG) {
+			d->mtu = s->mtu;
+			if (rfcomm_check_security(d)) {
+				rfcomm_send_pn(s, 1, d);
+			} else {
+				set_bit(RFCOMM_AUTH_PENDING, &d->flags);
+				rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
+			}
+		}
+	}
+}
+
+/* Send data queued for the DLC.
+ * Return number of frames left in the queue.
+ */
+static int rfcomm_process_tx(struct rfcomm_dlc *d)
+{
+	struct sk_buff *skb;
+	int err;
+
+	BT_DBG("dlc %p state %ld cfc %d rx_credits %d tx_credits %d",
+			d, d->state, d->cfc, d->rx_credits, d->tx_credits);
+
+	/* Send pending MSC */
+	if (test_and_clear_bit(RFCOMM_MSC_PENDING, &d->flags))
+		rfcomm_send_msc(d->session, 1, d->dlci, d->v24_sig);
+
+	if (d->cfc) {
+		/* CFC enabled.
+		 * Give them some credits */
+		if (!test_bit(RFCOMM_RX_THROTTLED, &d->flags) &&
+				d->rx_credits <= (d->cfc >> 2)) {
+			rfcomm_send_credits(d->session, d->addr, d->cfc - d->rx_credits);
+			d->rx_credits = d->cfc;
+		}
+	} else {
+		/* CFC disabled.
+		 * Give ourselves some credits */
+		d->tx_credits = 5;
+	}
+
+	if (test_bit(RFCOMM_TX_THROTTLED, &d->flags))
+		return skb_queue_len(&d->tx_queue);
+
+	while (d->tx_credits && (skb = skb_dequeue(&d->tx_queue))) {
+		err = rfcomm_send_frame(d->session, skb->data, skb->len);
+		if (err < 0) {
+			skb_queue_head(&d->tx_queue, skb);
+			break;
+		}
+		kfree_skb(skb);
+		d->tx_credits--;
+	}
+
+	if (d->cfc && !d->tx_credits) {
+		/* We're out of TX credits.
+		 * Set TX_THROTTLED flag to avoid unnesary wakeups by dlc_send. */
+		set_bit(RFCOMM_TX_THROTTLED, &d->flags);
+	}
+
+	return skb_queue_len(&d->tx_queue);
+}
+
+static void rfcomm_process_dlcs(struct rfcomm_session *s)
+{
+	struct rfcomm_dlc *d, *n;
+
+	BT_DBG("session %p state %ld", s, s->state);
+
+	list_for_each_entry_safe(d, n, &s->dlcs, list) {
+		if (test_bit(RFCOMM_TIMED_OUT, &d->flags)) {
+			__rfcomm_dlc_close(d, ETIMEDOUT);
+			continue;
+		}
+
+		if (test_bit(RFCOMM_ENC_DROP, &d->flags)) {
+			__rfcomm_dlc_close(d, ECONNREFUSED);
+			continue;
+		}
+
+		if (test_and_clear_bit(RFCOMM_AUTH_ACCEPT, &d->flags)) {
+			rfcomm_dlc_clear_timer(d);
+			if (d->out) {
+				rfcomm_send_pn(s, 1, d);
+				rfcomm_dlc_set_timer(d, RFCOMM_CONN_TIMEOUT);
+			} else {
+				if (d->defer_setup) {
+					set_bit(RFCOMM_DEFER_SETUP, &d->flags);
+					rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
+
+					rfcomm_dlc_lock(d);
+					d->state = BT_CONNECT2;
+					d->state_change(d, 0);
+					rfcomm_dlc_unlock(d);
+				} else
+					rfcomm_dlc_accept(d);
+			}
+			continue;
+		} else if (test_and_clear_bit(RFCOMM_AUTH_REJECT, &d->flags)) {
+			rfcomm_dlc_clear_timer(d);
+			if (!d->out)
+				rfcomm_send_dm(s, d->dlci);
+			else
+				d->state = BT_CLOSED;
+			__rfcomm_dlc_close(d, ECONNREFUSED);
+			continue;
+		}
+
+		if (test_bit(RFCOMM_SEC_PENDING, &d->flags))
+			continue;
+
+		if (test_bit(RFCOMM_TX_THROTTLED, &s->flags))
+			continue;
+
+		if ((d->state == BT_CONNECTED || d->state == BT_DISCONN) &&
+						d->mscex == RFCOMM_MSCEX_OK)
+			rfcomm_process_tx(d);
+	}
+}
+
+static struct rfcomm_session *rfcomm_process_rx(struct rfcomm_session *s)
+{
+	struct socket *sock = s->sock;
+	struct sock *sk = sock->sk;
+	struct sk_buff *skb;
+
+	BT_DBG("session %p state %ld qlen %d", s, s->state, skb_queue_len(&sk->sk_receive_queue));
+
+	/* Get data directly from socket receive queue without copying it. */
+	while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
+		skb_orphan(skb);
+		if (!skb_linearize(skb)) {
+			s = rfcomm_recv_frame(s, skb);
+			if (!s)
+				break;
+		} else {
+			kfree_skb(skb);
+		}
+	}
+
+	if (s && (sk->sk_state == BT_CLOSED))
+		s = rfcomm_session_close(s, sk->sk_err);
+
+	return s;
+}
+
+static void rfcomm_accept_connection(struct rfcomm_session *s)
+{
+	struct socket *sock = s->sock, *nsock;
+	int err;
+
+	/* Fast check for a new connection.
+	 * Avoids unnesesary socket allocations. */
+	if (list_empty(&bt_sk(sock->sk)->accept_q))
+		return;
+
+	BT_DBG("session %p", s);
+
+	err = kernel_accept(sock, &nsock, O_NONBLOCK);
+	if (err < 0)
+		return;
+
+	/* Set our callbacks */
+	nsock->sk->sk_data_ready   = rfcomm_l2data_ready;
+	nsock->sk->sk_state_change = rfcomm_l2state_change;
+
+	s = rfcomm_session_add(nsock, BT_OPEN);
+	if (s) {
+		/* We should adjust MTU on incoming sessions.
+		 * L2CAP MTU minus UIH header and FCS. */
+		s->mtu = min(l2cap_pi(nsock->sk)->chan->omtu,
+				l2cap_pi(nsock->sk)->chan->imtu) - 5;
+
+		rfcomm_schedule();
+	} else
+		sock_release(nsock);
+}
+
+static struct rfcomm_session *rfcomm_check_connection(struct rfcomm_session *s)
+{
+	struct sock *sk = s->sock->sk;
+
+	BT_DBG("%p state %ld", s, s->state);
+
+	switch (sk->sk_state) {
+	case BT_CONNECTED:
+		s->state = BT_CONNECT;
+
+		/* We can adjust MTU on outgoing sessions.
+		 * L2CAP MTU minus UIH header and FCS. */
+		s->mtu = min(l2cap_pi(sk)->chan->omtu, l2cap_pi(sk)->chan->imtu) - 5;
+
+		rfcomm_send_sabm(s, 0);
+		break;
+
+	case BT_CLOSED:
+		s = rfcomm_session_close(s, sk->sk_err);
+		break;
+	}
+	return s;
+}
+
+static void rfcomm_process_sessions(void)
+{
+	struct rfcomm_session *s, *n;
+
+	rfcomm_lock();
+
+	list_for_each_entry_safe(s, n, &session_list, list) {
+		if (test_and_clear_bit(RFCOMM_TIMED_OUT, &s->flags)) {
+			s->state = BT_DISCONN;
+			rfcomm_send_disc(s, 0);
+			continue;
+		}
+
+		switch (s->state) {
+		case BT_LISTEN:
+			rfcomm_accept_connection(s);
+			continue;
+
+		case BT_BOUND:
+			s = rfcomm_check_connection(s);
+			break;
+
+		default:
+			s = rfcomm_process_rx(s);
+			break;
+		}
+
+		if (s)
+			rfcomm_process_dlcs(s);
+	}
+
+	rfcomm_unlock();
+}
+
+static int rfcomm_add_listener(bdaddr_t *ba)
+{
+	struct sockaddr_l2 addr;
+	struct socket *sock;
+	struct sock *sk;
+	struct rfcomm_session *s;
+	int    err = 0;
+
+	/* Create socket */
+	err = rfcomm_l2sock_create(&sock);
+	if (err < 0) {
+		BT_ERR("Create socket failed %d", err);
+		return err;
+	}
+
+	/* Bind socket */
+	bacpy(&addr.l2_bdaddr, ba);
+	addr.l2_family = AF_BLUETOOTH;
+	addr.l2_psm    = cpu_to_le16(L2CAP_PSM_RFCOMM);
+	addr.l2_cid    = 0;
+	addr.l2_bdaddr_type = BDADDR_BREDR;
+	err = kernel_bind(sock, (struct sockaddr *) &addr, sizeof(addr));
+	if (err < 0) {
+		BT_ERR("Bind failed %d", err);
+		goto failed;
+	}
+
+	/* Set L2CAP options */
+	sk = sock->sk;
+	lock_sock(sk);
+	/* Set MTU to 0 so L2CAP can auto select the MTU */
+	l2cap_pi(sk)->chan->imtu = 0;
+	release_sock(sk);
+
+	/* Start listening on the socket */
+	err = kernel_listen(sock, 10);
+	if (err) {
+		BT_ERR("Listen failed %d", err);
+		goto failed;
+	}
+
+	/* Add listening session */
+	s = rfcomm_session_add(sock, BT_LISTEN);
+	if (!s) {
+		err = -ENOMEM;
+		goto failed;
+	}
+
+	return 0;
+failed:
+	sock_release(sock);
+	return err;
+}
+
+static void rfcomm_kill_listener(void)
+{
+	struct rfcomm_session *s, *n;
+
+	BT_DBG("");
+
+	list_for_each_entry_safe(s, n, &session_list, list)
+		rfcomm_session_del(s);
+}
+
+static int rfcomm_run(void *unused)
+{
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	BT_DBG("");
+
+	set_user_nice(current, -10);
+
+	rfcomm_add_listener(BDADDR_ANY);
+
+	add_wait_queue(&rfcomm_wq, &wait);
+	while (!kthread_should_stop()) {
+
+		/* Process stuff */
+		rfcomm_process_sessions();
+
+		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
+	}
+	remove_wait_queue(&rfcomm_wq, &wait);
+
+	rfcomm_kill_listener();
+
+	return 0;
+}
+
+static void rfcomm_security_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
+{
+	struct rfcomm_session *s;
+	struct rfcomm_dlc *d, *n;
+
+	BT_DBG("conn %p status 0x%02x encrypt 0x%02x", conn, status, encrypt);
+
+	s = rfcomm_session_get(&conn->hdev->bdaddr, &conn->dst);
+	if (!s)
+		return;
+
+	list_for_each_entry_safe(d, n, &s->dlcs, list) {
+		if (test_and_clear_bit(RFCOMM_SEC_PENDING, &d->flags)) {
+			rfcomm_dlc_clear_timer(d);
+			if (status || encrypt == 0x00) {
+				set_bit(RFCOMM_ENC_DROP, &d->flags);
+				continue;
+			}
+		}
+
+		if (d->state == BT_CONNECTED && !status && encrypt == 0x00) {
+			if (d->sec_level == BT_SECURITY_MEDIUM) {
+				set_bit(RFCOMM_SEC_PENDING, &d->flags);
+				rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
+				continue;
+			} else if (d->sec_level == BT_SECURITY_HIGH ||
+				   d->sec_level == BT_SECURITY_FIPS) {
+				set_bit(RFCOMM_ENC_DROP, &d->flags);
+				continue;
+			}
+		}
+
+		if (!test_and_clear_bit(RFCOMM_AUTH_PENDING, &d->flags))
+			continue;
+
+		if (!status && hci_conn_check_secure(conn, d->sec_level))
+			set_bit(RFCOMM_AUTH_ACCEPT, &d->flags);
+		else
+			set_bit(RFCOMM_AUTH_REJECT, &d->flags);
+	}
+
+	rfcomm_schedule();
+}
+
+static struct hci_cb rfcomm_cb = {
+	.name		= "RFCOMM",
+	.security_cfm	= rfcomm_security_cfm
+};
+
+static int rfcomm_dlc_debugfs_show(struct seq_file *f, void *x)
+{
+	struct rfcomm_session *s;
+
+	rfcomm_lock();
+
+	list_for_each_entry(s, &session_list, list) {
+		struct l2cap_chan *chan = l2cap_pi(s->sock->sk)->chan;
+		struct rfcomm_dlc *d;
+		list_for_each_entry(d, &s->dlcs, list) {
+			seq_printf(f, "%pMR %pMR %ld %d %d %d %d\n",
+				   &chan->src, &chan->dst,
+				   d->state, d->dlci, d->mtu,
+				   d->rx_credits, d->tx_credits);
+		}
+	}
+
+	rfcomm_unlock();
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(rfcomm_dlc_debugfs);
+
+static struct dentry *rfcomm_dlc_debugfs;
+
+/* ---- Initialization ---- */
+static int __init rfcomm_init(void)
+{
+	int err;
+
+	hci_register_cb(&rfcomm_cb);
+
+	rfcomm_thread = kthread_run(rfcomm_run, NULL, "krfcommd");
+	if (IS_ERR(rfcomm_thread)) {
+		err = PTR_ERR(rfcomm_thread);
+		goto unregister;
+	}
+
+	err = rfcomm_init_ttys();
+	if (err < 0)
+		goto stop;
+
+	err = rfcomm_init_sockets();
+	if (err < 0)
+		goto cleanup;
+
+	BT_INFO("RFCOMM ver %s", VERSION);
+
+	if (IS_ERR_OR_NULL(bt_debugfs))
+		return 0;
+
+	rfcomm_dlc_debugfs = debugfs_create_file("rfcomm_dlc", 0444,
+						 bt_debugfs, NULL,
+						 &rfcomm_dlc_debugfs_fops);
+
+	return 0;
+
+cleanup:
+	rfcomm_cleanup_ttys();
+
+stop:
+	kthread_stop(rfcomm_thread);
+
+unregister:
+	hci_unregister_cb(&rfcomm_cb);
+
+	return err;
+}
+
+static void __exit rfcomm_exit(void)
+{
+	debugfs_remove(rfcomm_dlc_debugfs);
+
+	hci_unregister_cb(&rfcomm_cb);
+
+	kthread_stop(rfcomm_thread);
+
+	rfcomm_cleanup_ttys();
+
+	rfcomm_cleanup_sockets();
+}
+
+module_init(rfcomm_init);
+module_exit(rfcomm_exit);
+
+module_param(disable_cfc, bool, 0644);
+MODULE_PARM_DESC(disable_cfc, "Disable credit based flow control");
+
+module_param(channel_mtu, int, 0644);
+MODULE_PARM_DESC(channel_mtu, "Default MTU for the RFCOMM channel");
+
+module_param(l2cap_ertm, bool, 0644);
+MODULE_PARM_DESC(l2cap_ertm, "Use L2CAP ERTM mode for connection");
+
+MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
+MODULE_DESCRIPTION("Bluetooth RFCOMM ver " VERSION);
+MODULE_VERSION(VERSION);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("bt-proto-3");
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
new file mode 100644
index 000000000..4cf1fa990
--- /dev/null
+++ b/net/bluetooth/rfcomm/sock.c
@@ -0,0 +1,1085 @@
+/*
+   RFCOMM implementation for Linux Bluetooth stack (BlueZ).
+   Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com>
+   Copyright (C) 2002 Marcel Holtmann <marcel@holtmann.org>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License version 2 as
+   published by the Free Software Foundation;
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
+   IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
+   CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
+   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+   ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
+   COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
+   SOFTWARE IS DISCLAIMED.
+*/
+
+/*
+ * RFCOMM sockets.
+ */
+#include <linux/compat.h>
+#include <linux/export.h>
+#include <linux/debugfs.h>
+#include <linux/sched/signal.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+#include <net/bluetooth/l2cap.h>
+#include <net/bluetooth/rfcomm.h>
+
+static const struct proto_ops rfcomm_sock_ops;
+
+static struct bt_sock_list rfcomm_sk_list = {
+	.lock = __RW_LOCK_UNLOCKED(rfcomm_sk_list.lock)
+};
+
+static void rfcomm_sock_close(struct sock *sk);
+static void rfcomm_sock_kill(struct sock *sk);
+
+/* ---- DLC callbacks ----
+ *
+ * called under rfcomm_dlc_lock()
+ */
+static void rfcomm_sk_data_ready(struct rfcomm_dlc *d, struct sk_buff *skb)
+{
+	struct sock *sk = d->owner;
+	if (!sk)
+		return;
+
+	atomic_add(skb->len, &sk->sk_rmem_alloc);
+	skb_queue_tail(&sk->sk_receive_queue, skb);
+	sk->sk_data_ready(sk);
+
+	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
+		rfcomm_dlc_throttle(d);
+}
+
+static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err)
+{
+	struct sock *sk = d->owner, *parent;
+
+	if (!sk)
+		return;
+
+	BT_DBG("dlc %p state %ld err %d", d, d->state, err);
+
+	spin_lock_bh(&sk->sk_lock.slock);
+
+	if (err)
+		sk->sk_err = err;
+
+	sk->sk_state = d->state;
+
+	parent = bt_sk(sk)->parent;
+	if (parent) {
+		if (d->state == BT_CLOSED) {
+			sock_set_flag(sk, SOCK_ZAPPED);
+			bt_accept_unlink(sk);
+		}
+		parent->sk_data_ready(parent);
+	} else {
+		if (d->state == BT_CONNECTED)
+			rfcomm_session_getaddr(d->session,
+					       &rfcomm_pi(sk)->src, NULL);
+		sk->sk_state_change(sk);
+	}
+
+	spin_unlock_bh(&sk->sk_lock.slock);
+
+	if (parent && sock_flag(sk, SOCK_ZAPPED)) {
+		/* We have to drop DLC lock here, otherwise
+		 * rfcomm_sock_destruct() will dead lock. */
+		rfcomm_dlc_unlock(d);
+		rfcomm_sock_kill(sk);
+		rfcomm_dlc_lock(d);
+	}
+}
+
+/* ---- Socket functions ---- */
+static struct sock *__rfcomm_get_listen_sock_by_addr(u8 channel, bdaddr_t *src)
+{
+	struct sock *sk = NULL;
+
+	sk_for_each(sk, &rfcomm_sk_list.head) {
+		if (rfcomm_pi(sk)->channel != channel)
+			continue;
+
+		if (bacmp(&rfcomm_pi(sk)->src, src))
+			continue;
+
+		if (sk->sk_state == BT_BOUND || sk->sk_state == BT_LISTEN)
+			break;
+	}
+
+	return sk ? sk : NULL;
+}
+
+/* Find socket with channel and source bdaddr.
+ * Returns closest match.
+ */
+static struct sock *rfcomm_get_sock_by_channel(int state, u8 channel, bdaddr_t *src)
+{
+	struct sock *sk = NULL, *sk1 = NULL;
+
+	read_lock(&rfcomm_sk_list.lock);
+
+	sk_for_each(sk, &rfcomm_sk_list.head) {
+		if (state && sk->sk_state != state)
+			continue;
+
+		if (rfcomm_pi(sk)->channel == channel) {
+			/* Exact match. */
+			if (!bacmp(&rfcomm_pi(sk)->src, src))
+				break;
+
+			/* Closest match */
+			if (!bacmp(&rfcomm_pi(sk)->src, BDADDR_ANY))
+				sk1 = sk;
+		}
+	}
+
+	read_unlock(&rfcomm_sk_list.lock);
+
+	return sk ? sk : sk1;
+}
+
+static void rfcomm_sock_destruct(struct sock *sk)
+{
+	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
+
+	BT_DBG("sk %p dlc %p", sk, d);
+
+	skb_queue_purge(&sk->sk_receive_queue);
+	skb_queue_purge(&sk->sk_write_queue);
+
+	rfcomm_dlc_lock(d);
+	rfcomm_pi(sk)->dlc = NULL;
+
+	/* Detach DLC if it's owned by this socket */
+	if (d->owner == sk)
+		d->owner = NULL;
+	rfcomm_dlc_unlock(d);
+
+	rfcomm_dlc_put(d);
+}
+
+static void rfcomm_sock_cleanup_listen(struct sock *parent)
+{
+	struct sock *sk;
+
+	BT_DBG("parent %p", parent);
+
+	/* Close not yet accepted dlcs */
+	while ((sk = bt_accept_dequeue(parent, NULL))) {
+		rfcomm_sock_close(sk);
+		rfcomm_sock_kill(sk);
+	}
+
+	parent->sk_state  = BT_CLOSED;
+	sock_set_flag(parent, SOCK_ZAPPED);
+}
+
+/* Kill socket (only if zapped and orphan)
+ * Must be called on unlocked socket.
+ */
+static void rfcomm_sock_kill(struct sock *sk)
+{
+	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
+		return;
+
+	BT_DBG("sk %p state %d refcnt %d", sk, sk->sk_state, refcount_read(&sk->sk_refcnt));
+
+	/* Kill poor orphan */
+	bt_sock_unlink(&rfcomm_sk_list, sk);
+	sock_set_flag(sk, SOCK_DEAD);
+	sock_put(sk);
+}
+
+static void __rfcomm_sock_close(struct sock *sk)
+{
+	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
+
+	BT_DBG("sk %p state %d socket %p", sk, sk->sk_state, sk->sk_socket);
+
+	switch (sk->sk_state) {
+	case BT_LISTEN:
+		rfcomm_sock_cleanup_listen(sk);
+		break;
+
+	case BT_CONNECT:
+	case BT_CONNECT2:
+	case BT_CONFIG:
+	case BT_CONNECTED:
+		rfcomm_dlc_close(d, 0);
+		fallthrough;
+
+	default:
+		sock_set_flag(sk, SOCK_ZAPPED);
+		break;
+	}
+}
+
+/* Close socket.
+ * Must be called on unlocked socket.
+ */
+static void rfcomm_sock_close(struct sock *sk)
+{
+	lock_sock(sk);
+	__rfcomm_sock_close(sk);
+	release_sock(sk);
+}
+
+static void rfcomm_sock_init(struct sock *sk, struct sock *parent)
+{
+	struct rfcomm_pinfo *pi = rfcomm_pi(sk);
+
+	BT_DBG("sk %p", sk);
+
+	if (parent) {
+		sk->sk_type = parent->sk_type;
+		pi->dlc->defer_setup = test_bit(BT_SK_DEFER_SETUP,
+						&bt_sk(parent)->flags);
+
+		pi->sec_level = rfcomm_pi(parent)->sec_level;
+		pi->role_switch = rfcomm_pi(parent)->role_switch;
+
+		security_sk_clone(parent, sk);
+	} else {
+		pi->dlc->defer_setup = 0;
+
+		pi->sec_level = BT_SECURITY_LOW;
+		pi->role_switch = 0;
+	}
+
+	pi->dlc->sec_level = pi->sec_level;
+	pi->dlc->role_switch = pi->role_switch;
+}
+
+static struct proto rfcomm_proto = {
+	.name		= "RFCOMM",
+	.owner		= THIS_MODULE,
+	.obj_size	= sizeof(struct rfcomm_pinfo)
+};
+
+static struct sock *rfcomm_sock_alloc(struct net *net, struct socket *sock, int proto, gfp_t prio, int kern)
+{
+	struct rfcomm_dlc *d;
+	struct sock *sk;
+
+	sk = sk_alloc(net, PF_BLUETOOTH, prio, &rfcomm_proto, kern);
+	if (!sk)
+		return NULL;
+
+	sock_init_data(sock, sk);
+	INIT_LIST_HEAD(&bt_sk(sk)->accept_q);
+
+	d = rfcomm_dlc_alloc(prio);
+	if (!d) {
+		sk_free(sk);
+		return NULL;
+	}
+
+	d->data_ready   = rfcomm_sk_data_ready;
+	d->state_change = rfcomm_sk_state_change;
+
+	rfcomm_pi(sk)->dlc = d;
+	d->owner = sk;
+
+	sk->sk_destruct = rfcomm_sock_destruct;
+	sk->sk_sndtimeo = RFCOMM_CONN_TIMEOUT;
+
+	sk->sk_sndbuf = RFCOMM_MAX_CREDITS * RFCOMM_DEFAULT_MTU * 10;
+	sk->sk_rcvbuf = RFCOMM_MAX_CREDITS * RFCOMM_DEFAULT_MTU * 10;
+
+	sock_reset_flag(sk, SOCK_ZAPPED);
+
+	sk->sk_protocol = proto;
+	sk->sk_state    = BT_OPEN;
+
+	bt_sock_link(&rfcomm_sk_list, sk);
+
+	BT_DBG("sk %p", sk);
+	return sk;
+}
+
+static int rfcomm_sock_create(struct net *net, struct socket *sock,
+			      int protocol, int kern)
+{
+	struct sock *sk;
+
+	BT_DBG("sock %p", sock);
+
+	sock->state = SS_UNCONNECTED;
+
+	if (sock->type != SOCK_STREAM && sock->type != SOCK_RAW)
+		return -ESOCKTNOSUPPORT;
+
+	sock->ops = &rfcomm_sock_ops;
+
+	sk = rfcomm_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern);
+	if (!sk)
+		return -ENOMEM;
+
+	rfcomm_sock_init(sk, NULL);
+	return 0;
+}
+
+static int rfcomm_sock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
+{
+	struct sockaddr_rc sa;
+	struct sock *sk = sock->sk;
+	int len, err = 0;
+
+	if (!addr || addr_len < offsetofend(struct sockaddr, sa_family) ||
+	    addr->sa_family != AF_BLUETOOTH)
+		return -EINVAL;
+
+	memset(&sa, 0, sizeof(sa));
+	len = min_t(unsigned int, sizeof(sa), addr_len);
+	memcpy(&sa, addr, len);
+
+	BT_DBG("sk %p %pMR", sk, &sa.rc_bdaddr);
+
+	lock_sock(sk);
+
+	if (sk->sk_state != BT_OPEN) {
+		err = -EBADFD;
+		goto done;
+	}
+
+	if (sk->sk_type != SOCK_STREAM) {
+		err = -EINVAL;
+		goto done;
+	}
+
+	write_lock(&rfcomm_sk_list.lock);
+
+	if (sa.rc_channel &&
+	    __rfcomm_get_listen_sock_by_addr(sa.rc_channel, &sa.rc_bdaddr)) {
+		err = -EADDRINUSE;
+	} else {
+		/* Save source address */
+		bacpy(&rfcomm_pi(sk)->src, &sa.rc_bdaddr);
+		rfcomm_pi(sk)->channel = sa.rc_channel;
+		sk->sk_state = BT_BOUND;
+	}
+
+	write_unlock(&rfcomm_sk_list.lock);
+
+done:
+	release_sock(sk);
+	return err;
+}
+
+static int rfcomm_sock_connect(struct socket *sock, struct sockaddr *addr, int alen, int flags)
+{
+	struct sockaddr_rc *sa = (struct sockaddr_rc *) addr;
+	struct sock *sk = sock->sk;
+	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
+	int err = 0;
+
+	BT_DBG("sk %p", sk);
+
+	if (alen < sizeof(struct sockaddr_rc) ||
+	    addr->sa_family != AF_BLUETOOTH)
+		return -EINVAL;
+
+	lock_sock(sk);
+
+	if (sk->sk_state != BT_OPEN && sk->sk_state != BT_BOUND) {
+		err = -EBADFD;
+		goto done;
+	}
+
+	if (sk->sk_type != SOCK_STREAM) {
+		err = -EINVAL;
+		goto done;
+	}
+
+	sk->sk_state = BT_CONNECT;
+	bacpy(&rfcomm_pi(sk)->dst, &sa->rc_bdaddr);
+	rfcomm_pi(sk)->channel = sa->rc_channel;
+
+	d->sec_level = rfcomm_pi(sk)->sec_level;
+	d->role_switch = rfcomm_pi(sk)->role_switch;
+
+	err = rfcomm_dlc_open(d, &rfcomm_pi(sk)->src, &sa->rc_bdaddr,
+			      sa->rc_channel);
+	if (!err)
+		err = bt_sock_wait_state(sk, BT_CONNECTED,
+				sock_sndtimeo(sk, flags & O_NONBLOCK));
+
+done:
+	release_sock(sk);
+	return err;
+}
+
+static int rfcomm_sock_listen(struct socket *sock, int backlog)
+{
+	struct sock *sk = sock->sk;
+	int err = 0;
+
+	BT_DBG("sk %p backlog %d", sk, backlog);
+
+	lock_sock(sk);
+
+	if (sk->sk_state != BT_BOUND) {
+		err = -EBADFD;
+		goto done;
+	}
+
+	if (sk->sk_type != SOCK_STREAM) {
+		err = -EINVAL;
+		goto done;
+	}
+
+	if (!rfcomm_pi(sk)->channel) {
+		bdaddr_t *src = &rfcomm_pi(sk)->src;
+		u8 channel;
+
+		err = -EINVAL;
+
+		write_lock(&rfcomm_sk_list.lock);
+
+		for (channel = 1; channel < 31; channel++)
+			if (!__rfcomm_get_listen_sock_by_addr(channel, src)) {
+				rfcomm_pi(sk)->channel = channel;
+				err = 0;
+				break;
+			}
+
+		write_unlock(&rfcomm_sk_list.lock);
+
+		if (err < 0)
+			goto done;
+	}
+
+	sk->sk_max_ack_backlog = backlog;
+	sk->sk_ack_backlog = 0;
+	sk->sk_state = BT_LISTEN;
+
+done:
+	release_sock(sk);
+	return err;
+}
+
+static int rfcomm_sock_accept(struct socket *sock, struct socket *newsock, int flags,
+			      bool kern)
+{
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	struct sock *sk = sock->sk, *nsk;
+	long timeo;
+	int err = 0;
+
+	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
+
+	if (sk->sk_type != SOCK_STREAM) {
+		err = -EINVAL;
+		goto done;
+	}
+
+	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
+
+	BT_DBG("sk %p timeo %ld", sk, timeo);
+
+	/* Wait for an incoming connection. (wake-one). */
+	add_wait_queue_exclusive(sk_sleep(sk), &wait);
+	while (1) {
+		if (sk->sk_state != BT_LISTEN) {
+			err = -EBADFD;
+			break;
+		}
+
+		nsk = bt_accept_dequeue(sk, newsock);
+		if (nsk)
+			break;
+
+		if (!timeo) {
+			err = -EAGAIN;
+			break;
+		}
+
+		if (signal_pending(current)) {
+			err = sock_intr_errno(timeo);
+			break;
+		}
+
+		release_sock(sk);
+
+		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
+
+		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
+	}
+	remove_wait_queue(sk_sleep(sk), &wait);
+
+	if (err)
+		goto done;
+
+	newsock->state = SS_CONNECTED;
+
+	BT_DBG("new socket %p", nsk);
+
+done:
+	release_sock(sk);
+	return err;
+}
+
+static int rfcomm_sock_getname(struct socket *sock, struct sockaddr *addr, int peer)
+{
+	struct sockaddr_rc *sa = (struct sockaddr_rc *) addr;
+	struct sock *sk = sock->sk;
+
+	BT_DBG("sock %p, sk %p", sock, sk);
+
+	if (peer && sk->sk_state != BT_CONNECTED &&
+	    sk->sk_state != BT_CONNECT && sk->sk_state != BT_CONNECT2)
+		return -ENOTCONN;
+
+	memset(sa, 0, sizeof(*sa));
+	sa->rc_family  = AF_BLUETOOTH;
+	sa->rc_channel = rfcomm_pi(sk)->channel;
+	if (peer)
+		bacpy(&sa->rc_bdaddr, &rfcomm_pi(sk)->dst);
+	else
+		bacpy(&sa->rc_bdaddr, &rfcomm_pi(sk)->src);
+
+	return sizeof(struct sockaddr_rc);
+}
+
+static int rfcomm_sock_sendmsg(struct socket *sock, struct msghdr *msg,
+			       size_t len)
+{
+	struct sock *sk = sock->sk;
+	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
+	struct sk_buff *skb;
+	int sent;
+
+	if (test_bit(RFCOMM_DEFER_SETUP, &d->flags))
+		return -ENOTCONN;
+
+	if (msg->msg_flags & MSG_OOB)
+		return -EOPNOTSUPP;
+
+	if (sk->sk_shutdown & SEND_SHUTDOWN)
+		return -EPIPE;
+
+	BT_DBG("sock %p, sk %p", sock, sk);
+
+	lock_sock(sk);
+
+	sent = bt_sock_wait_ready(sk, msg->msg_flags);
+
+	release_sock(sk);
+
+	if (sent)
+		return sent;
+
+	skb = bt_skb_sendmmsg(sk, msg, len, d->mtu, RFCOMM_SKB_HEAD_RESERVE,
+			      RFCOMM_SKB_TAIL_RESERVE);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
+
+	sent = rfcomm_dlc_send(d, skb);
+	if (sent < 0)
+		kfree_skb(skb);
+
+	return sent;
+}
+
+static int rfcomm_sock_recvmsg(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 len;
+
+	if (test_and_clear_bit(RFCOMM_DEFER_SETUP, &d->flags)) {
+		rfcomm_dlc_accept(d);
+		return 0;
+	}
+
+	len = bt_sock_stream_recvmsg(sock, msg, size, flags);
+
+	lock_sock(sk);
+	if (!(flags & MSG_PEEK) && len > 0)
+		atomic_sub(len, &sk->sk_rmem_alloc);
+
+	if (atomic_read(&sk->sk_rmem_alloc) <= (sk->sk_rcvbuf >> 2))
+		rfcomm_dlc_unthrottle(rfcomm_pi(sk)->dlc);
+	release_sock(sk);
+
+	return len;
+}
+
+static int rfcomm_sock_setsockopt_old(struct socket *sock, int optname,
+		sockptr_t optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	int err = 0;
+	u32 opt;
+
+	BT_DBG("sk %p", sk);
+
+	lock_sock(sk);
+
+	switch (optname) {
+	case RFCOMM_LM:
+		if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
+			err = -EFAULT;
+			break;
+		}
+
+		if (opt & RFCOMM_LM_FIPS) {
+			err = -EINVAL;
+			break;
+		}
+
+		if (opt & RFCOMM_LM_AUTH)
+			rfcomm_pi(sk)->sec_level = BT_SECURITY_LOW;
+		if (opt & RFCOMM_LM_ENCRYPT)
+			rfcomm_pi(sk)->sec_level = BT_SECURITY_MEDIUM;
+		if (opt & RFCOMM_LM_SECURE)
+			rfcomm_pi(sk)->sec_level = BT_SECURITY_HIGH;
+
+		rfcomm_pi(sk)->role_switch = (opt & RFCOMM_LM_MASTER);
+		break;
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	}
+
+	release_sock(sk);
+	return err;
+}
+
+static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname,
+		sockptr_t optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	struct bt_security sec;
+	int err = 0;
+	size_t len;
+	u32 opt;
+
+	BT_DBG("sk %p", sk);
+
+	if (level == SOL_RFCOMM)
+		return rfcomm_sock_setsockopt_old(sock, optname, optval, optlen);
+
+	if (level != SOL_BLUETOOTH)
+		return -ENOPROTOOPT;
+
+	lock_sock(sk);
+
+	switch (optname) {
+	case BT_SECURITY:
+		if (sk->sk_type != SOCK_STREAM) {
+			err = -EINVAL;
+			break;
+		}
+
+		sec.level = BT_SECURITY_LOW;
+
+		len = min_t(unsigned int, sizeof(sec), optlen);
+		if (copy_from_sockptr(&sec, optval, len)) {
+			err = -EFAULT;
+			break;
+		}
+
+		if (sec.level > BT_SECURITY_HIGH) {
+			err = -EINVAL;
+			break;
+		}
+
+		rfcomm_pi(sk)->sec_level = sec.level;
+		break;
+
+	case BT_DEFER_SETUP:
+		if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
+			err = -EINVAL;
+			break;
+		}
+
+		if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
+			err = -EFAULT;
+			break;
+		}
+
+		if (opt)
+			set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
+		else
+			clear_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
+
+		break;
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	}
+
+	release_sock(sk);
+	return err;
+}
+
+static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __user *optval, int __user *optlen)
+{
+	struct sock *sk = sock->sk;
+	struct sock *l2cap_sk;
+	struct l2cap_conn *conn;
+	struct rfcomm_conninfo cinfo;
+	int len, err = 0;
+	u32 opt;
+
+	BT_DBG("sk %p", sk);
+
+	if (get_user(len, optlen))
+		return -EFAULT;
+
+	lock_sock(sk);
+
+	switch (optname) {
+	case RFCOMM_LM:
+		switch (rfcomm_pi(sk)->sec_level) {
+		case BT_SECURITY_LOW:
+			opt = RFCOMM_LM_AUTH;
+			break;
+		case BT_SECURITY_MEDIUM:
+			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT;
+			break;
+		case BT_SECURITY_HIGH:
+			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT |
+			      RFCOMM_LM_SECURE;
+			break;
+		case BT_SECURITY_FIPS:
+			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT |
+			      RFCOMM_LM_SECURE | RFCOMM_LM_FIPS;
+			break;
+		default:
+			opt = 0;
+			break;
+		}
+
+		if (rfcomm_pi(sk)->role_switch)
+			opt |= RFCOMM_LM_MASTER;
+
+		if (put_user(opt, (u32 __user *) optval))
+			err = -EFAULT;
+
+		break;
+
+	case RFCOMM_CONNINFO:
+		if (sk->sk_state != BT_CONNECTED &&
+					!rfcomm_pi(sk)->dlc->defer_setup) {
+			err = -ENOTCONN;
+			break;
+		}
+
+		l2cap_sk = rfcomm_pi(sk)->dlc->session->sock->sk;
+		conn = l2cap_pi(l2cap_sk)->chan->conn;
+
+		memset(&cinfo, 0, sizeof(cinfo));
+		cinfo.hci_handle = conn->hcon->handle;
+		memcpy(cinfo.dev_class, conn->hcon->dev_class, 3);
+
+		len = min_t(unsigned int, len, sizeof(cinfo));
+		if (copy_to_user(optval, (char *) &cinfo, len))
+			err = -EFAULT;
+
+		break;
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	}
+
+	release_sock(sk);
+	return err;
+}
+
+static int rfcomm_sock_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen)
+{
+	struct sock *sk = sock->sk;
+	struct bt_security sec;
+	int len, err = 0;
+
+	BT_DBG("sk %p", sk);
+
+	if (level == SOL_RFCOMM)
+		return rfcomm_sock_getsockopt_old(sock, optname, optval, optlen);
+
+	if (level != SOL_BLUETOOTH)
+		return -ENOPROTOOPT;
+
+	if (get_user(len, optlen))
+		return -EFAULT;
+
+	lock_sock(sk);
+
+	switch (optname) {
+	case BT_SECURITY:
+		if (sk->sk_type != SOCK_STREAM) {
+			err = -EINVAL;
+			break;
+		}
+
+		sec.level = rfcomm_pi(sk)->sec_level;
+		sec.key_size = 0;
+
+		len = min_t(unsigned int, len, sizeof(sec));
+		if (copy_to_user(optval, (char *) &sec, len))
+			err = -EFAULT;
+
+		break;
+
+	case BT_DEFER_SETUP:
+		if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
+			err = -EINVAL;
+			break;
+		}
+
+		if (put_user(test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags),
+			     (u32 __user *) optval))
+			err = -EFAULT;
+
+		break;
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	}
+
+	release_sock(sk);
+	return err;
+}
+
+static int rfcomm_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+	struct sock *sk __maybe_unused = sock->sk;
+	int err;
+
+	BT_DBG("sk %p cmd %x arg %lx", sk, cmd, arg);
+
+	err = bt_sock_ioctl(sock, cmd, arg);
+
+	if (err == -ENOIOCTLCMD) {
+#ifdef CONFIG_BT_RFCOMM_TTY
+		lock_sock(sk);
+		err = rfcomm_dev_ioctl(sk, cmd, (void __user *) arg);
+		release_sock(sk);
+#else
+		err = -EOPNOTSUPP;
+#endif
+	}
+
+	return err;
+}
+
+#ifdef CONFIG_COMPAT
+static int rfcomm_sock_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+	return rfcomm_sock_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static int rfcomm_sock_shutdown(struct socket *sock, int how)
+{
+	struct sock *sk = sock->sk;
+	int err = 0;
+
+	BT_DBG("sock %p, sk %p", sock, sk);
+
+	if (!sk)
+		return 0;
+
+	lock_sock(sk);
+	if (!sk->sk_shutdown) {
+		sk->sk_shutdown = SHUTDOWN_MASK;
+		__rfcomm_sock_close(sk);
+
+		if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
+		    !(current->flags & PF_EXITING))
+			err = bt_sock_wait_state(sk, BT_CLOSED, sk->sk_lingertime);
+	}
+	release_sock(sk);
+	return err;
+}
+
+static int rfcomm_sock_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	int err;
+
+	BT_DBG("sock %p, sk %p", sock, sk);
+
+	if (!sk)
+		return 0;
+
+	err = rfcomm_sock_shutdown(sock, 2);
+
+	sock_orphan(sk);
+	rfcomm_sock_kill(sk);
+	return err;
+}
+
+/* ---- RFCOMM core layer callbacks ----
+ *
+ * called under rfcomm_lock()
+ */
+int rfcomm_connect_ind(struct rfcomm_session *s, u8 channel, struct rfcomm_dlc **d)
+{
+	struct sock *sk, *parent;
+	bdaddr_t src, dst;
+	int result = 0;
+
+	BT_DBG("session %p channel %d", s, channel);
+
+	rfcomm_session_getaddr(s, &src, &dst);
+
+	/* Check if we have socket listening on channel */
+	parent = rfcomm_get_sock_by_channel(BT_LISTEN, channel, &src);
+	if (!parent)
+		return 0;
+
+	bh_lock_sock(parent);
+
+	/* Check for backlog size */
+	if (sk_acceptq_is_full(parent)) {
+		BT_DBG("backlog full %d", parent->sk_ack_backlog);
+		goto done;
+	}
+
+	sk = rfcomm_sock_alloc(sock_net(parent), NULL, BTPROTO_RFCOMM, GFP_ATOMIC, 0);
+	if (!sk)
+		goto done;
+
+	bt_sock_reclassify_lock(sk, BTPROTO_RFCOMM);
+
+	rfcomm_sock_init(sk, parent);
+	bacpy(&rfcomm_pi(sk)->src, &src);
+	bacpy(&rfcomm_pi(sk)->dst, &dst);
+	rfcomm_pi(sk)->channel = channel;
+
+	sk->sk_state = BT_CONFIG;
+	bt_accept_enqueue(parent, sk, true);
+
+	/* Accept connection and return socket DLC */
+	*d = rfcomm_pi(sk)->dlc;
+	result = 1;
+
+done:
+	bh_unlock_sock(parent);
+
+	if (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags))
+		parent->sk_state_change(parent);
+
+	return result;
+}
+
+static int rfcomm_sock_debugfs_show(struct seq_file *f, void *p)
+{
+	struct sock *sk;
+
+	read_lock(&rfcomm_sk_list.lock);
+
+	sk_for_each(sk, &rfcomm_sk_list.head) {
+		seq_printf(f, "%pMR %pMR %d %d\n",
+			   &rfcomm_pi(sk)->src, &rfcomm_pi(sk)->dst,
+			   sk->sk_state, rfcomm_pi(sk)->channel);
+	}
+
+	read_unlock(&rfcomm_sk_list.lock);
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(rfcomm_sock_debugfs);
+
+static struct dentry *rfcomm_sock_debugfs;
+
+static const struct proto_ops rfcomm_sock_ops = {
+	.family		= PF_BLUETOOTH,
+	.owner		= THIS_MODULE,
+	.release	= rfcomm_sock_release,
+	.bind		= rfcomm_sock_bind,
+	.connect	= rfcomm_sock_connect,
+	.listen		= rfcomm_sock_listen,
+	.accept		= rfcomm_sock_accept,
+	.getname	= rfcomm_sock_getname,
+	.sendmsg	= rfcomm_sock_sendmsg,
+	.recvmsg	= rfcomm_sock_recvmsg,
+	.shutdown	= rfcomm_sock_shutdown,
+	.setsockopt	= rfcomm_sock_setsockopt,
+	.getsockopt	= rfcomm_sock_getsockopt,
+	.ioctl		= rfcomm_sock_ioctl,
+	.gettstamp	= sock_gettstamp,
+	.poll		= bt_sock_poll,
+	.socketpair	= sock_no_socketpair,
+	.mmap		= sock_no_mmap,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= rfcomm_sock_compat_ioctl,
+#endif
+};
+
+static const struct net_proto_family rfcomm_sock_family_ops = {
+	.family		= PF_BLUETOOTH,
+	.owner		= THIS_MODULE,
+	.create		= rfcomm_sock_create
+};
+
+int __init rfcomm_init_sockets(void)
+{
+	int err;
+
+	BUILD_BUG_ON(sizeof(struct sockaddr_rc) > sizeof(struct sockaddr));
+
+	err = proto_register(&rfcomm_proto, 0);
+	if (err < 0)
+		return err;
+
+	err = bt_sock_register(BTPROTO_RFCOMM, &rfcomm_sock_family_ops);
+	if (err < 0) {
+		BT_ERR("RFCOMM socket layer registration failed");
+		goto error;
+	}
+
+	err = bt_procfs_init(&init_net, "rfcomm", &rfcomm_sk_list, NULL);
+	if (err < 0) {
+		BT_ERR("Failed to create RFCOMM proc file");
+		bt_sock_unregister(BTPROTO_RFCOMM);
+		goto error;
+	}
+
+	BT_INFO("RFCOMM socket layer initialized");
+
+	if (IS_ERR_OR_NULL(bt_debugfs))
+		return 0;
+
+	rfcomm_sock_debugfs = debugfs_create_file("rfcomm", 0444,
+						  bt_debugfs, NULL,
+						  &rfcomm_sock_debugfs_fops);
+
+	return 0;
+
+error:
+	proto_unregister(&rfcomm_proto);
+	return err;
+}
+
+void __exit rfcomm_cleanup_sockets(void)
+{
+	bt_procfs_cleanup(&init_net, "rfcomm");
+
+	debugfs_remove(rfcomm_sock_debugfs);
+
+	bt_sock_unregister(BTPROTO_RFCOMM);
+
+	proto_unregister(&rfcomm_proto);
+}
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
new file mode 100644
index 000000000..a58584949
--- /dev/null
+++ b/net/bluetooth/rfcomm/tty.c
@@ -0,0 +1,1160 @@
+/*
+   RFCOMM implementation for Linux Bluetooth stack (BlueZ).
+   Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com>
+   Copyright (C) 2002 Marcel Holtmann <marcel@holtmann.org>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License version 2 as
+   published by the Free Software Foundation;
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
+   IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
+   CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
+   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+   ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
+   COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
+   SOFTWARE IS DISCLAIMED.
+*/
+
+/*
+ * RFCOMM TTY.
+ */
+
+#include <linux/module.h>
+
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+#include <net/bluetooth/rfcomm.h>
+
+#define RFCOMM_TTY_MAGIC 0x6d02		/* magic number for rfcomm struct */
+#define RFCOMM_TTY_PORTS RFCOMM_MAX_DEV	/* whole lotta rfcomm devices */
+#define RFCOMM_TTY_MAJOR 216		/* device node major id of the usb/bluetooth.c driver */
+#define RFCOMM_TTY_MINOR 0
+
+static DEFINE_MUTEX(rfcomm_ioctl_mutex);
+static struct tty_driver *rfcomm_tty_driver;
+
+struct rfcomm_dev {
+	struct tty_port		port;
+	struct list_head	list;
+
+	char			name[12];
+	int			id;
+	unsigned long		flags;
+	int			err;
+
+	unsigned long		status;		/* don't export to userspace */
+
+	bdaddr_t		src;
+	bdaddr_t		dst;
+	u8			channel;
+
+	uint			modem_status;
+
+	struct rfcomm_dlc	*dlc;
+
+	struct device		*tty_dev;
+
+	atomic_t		wmem_alloc;
+
+	struct sk_buff_head	pending;
+};
+
+static LIST_HEAD(rfcomm_dev_list);
+static DEFINE_MUTEX(rfcomm_dev_lock);
+
+static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb);
+static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err);
+static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig);
+
+/* ---- Device functions ---- */
+
+static void rfcomm_dev_destruct(struct tty_port *port)
+{
+	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
+	struct rfcomm_dlc *dlc = dev->dlc;
+
+	BT_DBG("dev %p dlc %p", dev, dlc);
+
+	rfcomm_dlc_lock(dlc);
+	/* Detach DLC if it's owned by this dev */
+	if (dlc->owner == dev)
+		dlc->owner = NULL;
+	rfcomm_dlc_unlock(dlc);
+
+	rfcomm_dlc_put(dlc);
+
+	if (dev->tty_dev)
+		tty_unregister_device(rfcomm_tty_driver, dev->id);
+
+	mutex_lock(&rfcomm_dev_lock);
+	list_del(&dev->list);
+	mutex_unlock(&rfcomm_dev_lock);
+
+	kfree(dev);
+
+	/* It's safe to call module_put() here because socket still
+	   holds reference to this module. */
+	module_put(THIS_MODULE);
+}
+
+/* device-specific initialization: open the dlc */
+static int rfcomm_dev_activate(struct tty_port *port, struct tty_struct *tty)
+{
+	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
+	int err;
+
+	err = rfcomm_dlc_open(dev->dlc, &dev->src, &dev->dst, dev->channel);
+	if (err)
+		set_bit(TTY_IO_ERROR, &tty->flags);
+	return err;
+}
+
+/* we block the open until the dlc->state becomes BT_CONNECTED */
+static int rfcomm_dev_carrier_raised(struct tty_port *port)
+{
+	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
+
+	return (dev->dlc->state == BT_CONNECTED);
+}
+
+/* device-specific cleanup: close the dlc */
+static void rfcomm_dev_shutdown(struct tty_port *port)
+{
+	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
+
+	if (dev->tty_dev->parent)
+		device_move(dev->tty_dev, NULL, DPM_ORDER_DEV_LAST);
+
+	/* close the dlc */
+	rfcomm_dlc_close(dev->dlc, 0);
+}
+
+static const struct tty_port_operations rfcomm_port_ops = {
+	.destruct = rfcomm_dev_destruct,
+	.activate = rfcomm_dev_activate,
+	.shutdown = rfcomm_dev_shutdown,
+	.carrier_raised = rfcomm_dev_carrier_raised,
+};
+
+static struct rfcomm_dev *__rfcomm_dev_lookup(int id)
+{
+	struct rfcomm_dev *dev;
+
+	list_for_each_entry(dev, &rfcomm_dev_list, list)
+		if (dev->id == id)
+			return dev;
+
+	return NULL;
+}
+
+static struct rfcomm_dev *rfcomm_dev_get(int id)
+{
+	struct rfcomm_dev *dev;
+
+	mutex_lock(&rfcomm_dev_lock);
+
+	dev = __rfcomm_dev_lookup(id);
+
+	if (dev && !tty_port_get(&dev->port))
+		dev = NULL;
+
+	mutex_unlock(&rfcomm_dev_lock);
+
+	return dev;
+}
+
+static void rfcomm_reparent_device(struct rfcomm_dev *dev)
+{
+	struct hci_dev *hdev;
+	struct hci_conn *conn;
+
+	hdev = hci_get_route(&dev->dst, &dev->src, BDADDR_BREDR);
+	if (!hdev)
+		return;
+
+	/* The lookup results are unsafe to access without the
+	 * hci device lock (FIXME: why is this not documented?)
+	 */
+	hci_dev_lock(hdev);
+	conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &dev->dst);
+
+	/* Just because the acl link is in the hash table is no
+	 * guarantee the sysfs device has been added ...
+	 */
+	if (conn && device_is_registered(&conn->dev))
+		device_move(dev->tty_dev, &conn->dev, DPM_ORDER_DEV_AFTER_PARENT);
+
+	hci_dev_unlock(hdev);
+	hci_dev_put(hdev);
+}
+
+static ssize_t show_address(struct device *tty_dev, struct device_attribute *attr, char *buf)
+{
+	struct rfcomm_dev *dev = dev_get_drvdata(tty_dev);
+	return sprintf(buf, "%pMR\n", &dev->dst);
+}
+
+static ssize_t show_channel(struct device *tty_dev, struct device_attribute *attr, char *buf)
+{
+	struct rfcomm_dev *dev = dev_get_drvdata(tty_dev);
+	return sprintf(buf, "%d\n", dev->channel);
+}
+
+static DEVICE_ATTR(address, 0444, show_address, NULL);
+static DEVICE_ATTR(channel, 0444, show_channel, NULL);
+
+static struct rfcomm_dev *__rfcomm_dev_add(struct rfcomm_dev_req *req,
+					   struct rfcomm_dlc *dlc)
+{
+	struct rfcomm_dev *dev, *entry;
+	struct list_head *head = &rfcomm_dev_list;
+	int err = 0;
+
+	dev = kzalloc(sizeof(struct rfcomm_dev), GFP_KERNEL);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_lock(&rfcomm_dev_lock);
+
+	if (req->dev_id < 0) {
+		dev->id = 0;
+
+		list_for_each_entry(entry, &rfcomm_dev_list, list) {
+			if (entry->id != dev->id)
+				break;
+
+			dev->id++;
+			head = &entry->list;
+		}
+	} else {
+		dev->id = req->dev_id;
+
+		list_for_each_entry(entry, &rfcomm_dev_list, list) {
+			if (entry->id == dev->id) {
+				err = -EADDRINUSE;
+				goto out;
+			}
+
+			if (entry->id > dev->id - 1)
+				break;
+
+			head = &entry->list;
+		}
+	}
+
+	if ((dev->id < 0) || (dev->id > RFCOMM_MAX_DEV - 1)) {
+		err = -ENFILE;
+		goto out;
+	}
+
+	sprintf(dev->name, "rfcomm%d", dev->id);
+
+	list_add(&dev->list, head);
+
+	bacpy(&dev->src, &req->src);
+	bacpy(&dev->dst, &req->dst);
+	dev->channel = req->channel;
+
+	dev->flags = req->flags &
+		((1 << RFCOMM_RELEASE_ONHUP) | (1 << RFCOMM_REUSE_DLC));
+
+	tty_port_init(&dev->port);
+	dev->port.ops = &rfcomm_port_ops;
+
+	skb_queue_head_init(&dev->pending);
+
+	rfcomm_dlc_lock(dlc);
+
+	if (req->flags & (1 << RFCOMM_REUSE_DLC)) {
+		struct sock *sk = dlc->owner;
+		struct sk_buff *skb;
+
+		BUG_ON(!sk);
+
+		rfcomm_dlc_throttle(dlc);
+
+		while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
+			skb_orphan(skb);
+			skb_queue_tail(&dev->pending, skb);
+			atomic_sub(skb->len, &sk->sk_rmem_alloc);
+		}
+	}
+
+	dlc->data_ready   = rfcomm_dev_data_ready;
+	dlc->state_change = rfcomm_dev_state_change;
+	dlc->modem_status = rfcomm_dev_modem_status;
+
+	dlc->owner = dev;
+	dev->dlc   = dlc;
+
+	rfcomm_dev_modem_status(dlc, dlc->remote_v24_sig);
+
+	rfcomm_dlc_unlock(dlc);
+
+	/* It's safe to call __module_get() here because socket already
+	   holds reference to this module. */
+	__module_get(THIS_MODULE);
+
+	mutex_unlock(&rfcomm_dev_lock);
+	return dev;
+
+out:
+	mutex_unlock(&rfcomm_dev_lock);
+	kfree(dev);
+	return ERR_PTR(err);
+}
+
+static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
+{
+	struct rfcomm_dev *dev;
+	struct device *tty;
+
+	BT_DBG("id %d channel %d", req->dev_id, req->channel);
+
+	dev = __rfcomm_dev_add(req, dlc);
+	if (IS_ERR(dev)) {
+		rfcomm_dlc_put(dlc);
+		return PTR_ERR(dev);
+	}
+
+	tty = tty_port_register_device(&dev->port, rfcomm_tty_driver,
+			dev->id, NULL);
+	if (IS_ERR(tty)) {
+		tty_port_put(&dev->port);
+		return PTR_ERR(tty);
+	}
+
+	dev->tty_dev = tty;
+	rfcomm_reparent_device(dev);
+	dev_set_drvdata(dev->tty_dev, dev);
+
+	if (device_create_file(dev->tty_dev, &dev_attr_address) < 0)
+		BT_ERR("Failed to create address attribute");
+
+	if (device_create_file(dev->tty_dev, &dev_attr_channel) < 0)
+		BT_ERR("Failed to create channel attribute");
+
+	return dev->id;
+}
+
+/* ---- Send buffer ---- */
+static inline unsigned int rfcomm_room(struct rfcomm_dev *dev)
+{
+	struct rfcomm_dlc *dlc = dev->dlc;
+
+	/* Limit the outstanding number of packets not yet sent to 40 */
+	int pending = 40 - atomic_read(&dev->wmem_alloc);
+
+	return max(0, pending) * dlc->mtu;
+}
+
+static void rfcomm_wfree(struct sk_buff *skb)
+{
+	struct rfcomm_dev *dev = (void *) skb->sk;
+	atomic_dec(&dev->wmem_alloc);
+	if (test_bit(RFCOMM_TTY_ATTACHED, &dev->flags))
+		tty_port_tty_wakeup(&dev->port);
+	tty_port_put(&dev->port);
+}
+
+static void rfcomm_set_owner_w(struct sk_buff *skb, struct rfcomm_dev *dev)
+{
+	tty_port_get(&dev->port);
+	atomic_inc(&dev->wmem_alloc);
+	skb->sk = (void *) dev;
+	skb->destructor = rfcomm_wfree;
+}
+
+static struct sk_buff *rfcomm_wmalloc(struct rfcomm_dev *dev, unsigned long size, gfp_t priority)
+{
+	struct sk_buff *skb = alloc_skb(size, priority);
+	if (skb)
+		rfcomm_set_owner_w(skb, dev);
+	return skb;
+}
+
+/* ---- Device IOCTLs ---- */
+
+#define NOCAP_FLAGS ((1 << RFCOMM_REUSE_DLC) | (1 << RFCOMM_RELEASE_ONHUP))
+
+static int __rfcomm_create_dev(struct sock *sk, void __user *arg)
+{
+	struct rfcomm_dev_req req;
+	struct rfcomm_dlc *dlc;
+	int id;
+
+	if (copy_from_user(&req, arg, sizeof(req)))
+		return -EFAULT;
+
+	BT_DBG("sk %p dev_id %d flags 0x%x", sk, req.dev_id, req.flags);
+
+	if (req.flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
+		/* Socket must be connected */
+		if (sk->sk_state != BT_CONNECTED)
+			return -EBADFD;
+
+		dlc = rfcomm_pi(sk)->dlc;
+		rfcomm_dlc_hold(dlc);
+	} else {
+		/* Validate the channel is unused */
+		dlc = rfcomm_dlc_exists(&req.src, &req.dst, req.channel);
+		if (IS_ERR(dlc))
+			return PTR_ERR(dlc);
+		if (dlc)
+			return -EBUSY;
+		dlc = rfcomm_dlc_alloc(GFP_KERNEL);
+		if (!dlc)
+			return -ENOMEM;
+	}
+
+	id = rfcomm_dev_add(&req, dlc);
+	if (id < 0)
+		return id;
+
+	if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
+		/* DLC is now used by device.
+		 * Socket must be disconnected */
+		sk->sk_state = BT_CLOSED;
+	}
+
+	return id;
+}
+
+static int __rfcomm_release_dev(void __user *arg)
+{
+	struct rfcomm_dev_req req;
+	struct rfcomm_dev *dev;
+	struct tty_struct *tty;
+
+	if (copy_from_user(&req, arg, sizeof(req)))
+		return -EFAULT;
+
+	BT_DBG("dev_id %d flags 0x%x", req.dev_id, req.flags);
+
+	dev = rfcomm_dev_get(req.dev_id);
+	if (!dev)
+		return -ENODEV;
+
+	if (dev->flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN)) {
+		tty_port_put(&dev->port);
+		return -EPERM;
+	}
+
+	/* only release once */
+	if (test_and_set_bit(RFCOMM_DEV_RELEASED, &dev->status)) {
+		tty_port_put(&dev->port);
+		return -EALREADY;
+	}
+
+	if (req.flags & (1 << RFCOMM_HANGUP_NOW))
+		rfcomm_dlc_close(dev->dlc, 0);
+
+	/* Shut down TTY synchronously before freeing rfcomm_dev */
+	tty = tty_port_tty_get(&dev->port);
+	if (tty) {
+		tty_vhangup(tty);
+		tty_kref_put(tty);
+	}
+
+	if (!test_bit(RFCOMM_TTY_OWNED, &dev->status))
+		tty_port_put(&dev->port);
+
+	tty_port_put(&dev->port);
+	return 0;
+}
+
+static int rfcomm_create_dev(struct sock *sk, void __user *arg)
+{
+	int ret;
+
+	mutex_lock(&rfcomm_ioctl_mutex);
+	ret = __rfcomm_create_dev(sk, arg);
+	mutex_unlock(&rfcomm_ioctl_mutex);
+
+	return ret;
+}
+
+static int rfcomm_release_dev(void __user *arg)
+{
+	int ret;
+
+	mutex_lock(&rfcomm_ioctl_mutex);
+	ret = __rfcomm_release_dev(arg);
+	mutex_unlock(&rfcomm_ioctl_mutex);
+
+	return ret;
+}
+
+static int rfcomm_get_dev_list(void __user *arg)
+{
+	struct rfcomm_dev *dev;
+	struct rfcomm_dev_list_req *dl;
+	struct rfcomm_dev_info *di;
+	int n = 0, size, err;
+	u16 dev_num;
+
+	BT_DBG("");
+
+	if (get_user(dev_num, (u16 __user *) arg))
+		return -EFAULT;
+
+	if (!dev_num || dev_num > (PAGE_SIZE * 4) / sizeof(*di))
+		return -EINVAL;
+
+	size = sizeof(*dl) + dev_num * sizeof(*di);
+
+	dl = kzalloc(size, GFP_KERNEL);
+	if (!dl)
+		return -ENOMEM;
+
+	di = dl->dev_info;
+
+	mutex_lock(&rfcomm_dev_lock);
+
+	list_for_each_entry(dev, &rfcomm_dev_list, list) {
+		if (!tty_port_get(&dev->port))
+			continue;
+		(di + n)->id      = dev->id;
+		(di + n)->flags   = dev->flags;
+		(di + n)->state   = dev->dlc->state;
+		(di + n)->channel = dev->channel;
+		bacpy(&(di + n)->src, &dev->src);
+		bacpy(&(di + n)->dst, &dev->dst);
+		tty_port_put(&dev->port);
+		if (++n >= dev_num)
+			break;
+	}
+
+	mutex_unlock(&rfcomm_dev_lock);
+
+	dl->dev_num = n;
+	size = sizeof(*dl) + n * sizeof(*di);
+
+	err = copy_to_user(arg, dl, size);
+	kfree(dl);
+
+	return err ? -EFAULT : 0;
+}
+
+static int rfcomm_get_dev_info(void __user *arg)
+{
+	struct rfcomm_dev *dev;
+	struct rfcomm_dev_info di;
+	int err = 0;
+
+	BT_DBG("");
+
+	if (copy_from_user(&di, arg, sizeof(di)))
+		return -EFAULT;
+
+	dev = rfcomm_dev_get(di.id);
+	if (!dev)
+		return -ENODEV;
+
+	di.flags   = dev->flags;
+	di.channel = dev->channel;
+	di.state   = dev->dlc->state;
+	bacpy(&di.src, &dev->src);
+	bacpy(&di.dst, &dev->dst);
+
+	if (copy_to_user(arg, &di, sizeof(di)))
+		err = -EFAULT;
+
+	tty_port_put(&dev->port);
+	return err;
+}
+
+int rfcomm_dev_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
+{
+	BT_DBG("cmd %d arg %p", cmd, arg);
+
+	switch (cmd) {
+	case RFCOMMCREATEDEV:
+		return rfcomm_create_dev(sk, arg);
+
+	case RFCOMMRELEASEDEV:
+		return rfcomm_release_dev(arg);
+
+	case RFCOMMGETDEVLIST:
+		return rfcomm_get_dev_list(arg);
+
+	case RFCOMMGETDEVINFO:
+		return rfcomm_get_dev_info(arg);
+	}
+
+	return -EINVAL;
+}
+
+/* ---- DLC callbacks ---- */
+static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb)
+{
+	struct rfcomm_dev *dev = dlc->owner;
+
+	if (!dev) {
+		kfree_skb(skb);
+		return;
+	}
+
+	if (!skb_queue_empty(&dev->pending)) {
+		skb_queue_tail(&dev->pending, skb);
+		return;
+	}
+
+	BT_DBG("dlc %p len %d", dlc, skb->len);
+
+	tty_insert_flip_string(&dev->port, skb->data, skb->len);
+	tty_flip_buffer_push(&dev->port);
+
+	kfree_skb(skb);
+}
+
+static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
+{
+	struct rfcomm_dev *dev = dlc->owner;
+	if (!dev)
+		return;
+
+	BT_DBG("dlc %p dev %p err %d", dlc, dev, err);
+
+	dev->err = err;
+	if (dlc->state == BT_CONNECTED) {
+		rfcomm_reparent_device(dev);
+
+		wake_up_interruptible(&dev->port.open_wait);
+	} else if (dlc->state == BT_CLOSED)
+		tty_port_tty_hangup(&dev->port, false);
+}
+
+static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)
+{
+	struct rfcomm_dev *dev = dlc->owner;
+	if (!dev)
+		return;
+
+	BT_DBG("dlc %p dev %p v24_sig 0x%02x", dlc, dev, v24_sig);
+
+	if ((dev->modem_status & TIOCM_CD) && !(v24_sig & RFCOMM_V24_DV))
+		tty_port_tty_hangup(&dev->port, true);
+
+	dev->modem_status =
+		((v24_sig & RFCOMM_V24_RTC) ? (TIOCM_DSR | TIOCM_DTR) : 0) |
+		((v24_sig & RFCOMM_V24_RTR) ? (TIOCM_RTS | TIOCM_CTS) : 0) |
+		((v24_sig & RFCOMM_V24_IC)  ? TIOCM_RI : 0) |
+		((v24_sig & RFCOMM_V24_DV)  ? TIOCM_CD : 0);
+}
+
+/* ---- TTY functions ---- */
+static void rfcomm_tty_copy_pending(struct rfcomm_dev *dev)
+{
+	struct sk_buff *skb;
+	int inserted = 0;
+
+	BT_DBG("dev %p", dev);
+
+	rfcomm_dlc_lock(dev->dlc);
+
+	while ((skb = skb_dequeue(&dev->pending))) {
+		inserted += tty_insert_flip_string(&dev->port, skb->data,
+				skb->len);
+		kfree_skb(skb);
+	}
+
+	rfcomm_dlc_unlock(dev->dlc);
+
+	if (inserted > 0)
+		tty_flip_buffer_push(&dev->port);
+}
+
+/* do the reverse of install, clearing the tty fields and releasing the
+ * reference to tty_port
+ */
+static void rfcomm_tty_cleanup(struct tty_struct *tty)
+{
+	struct rfcomm_dev *dev = tty->driver_data;
+
+	clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
+
+	rfcomm_dlc_lock(dev->dlc);
+	tty->driver_data = NULL;
+	rfcomm_dlc_unlock(dev->dlc);
+
+	/*
+	 * purge the dlc->tx_queue to avoid circular dependencies
+	 * between dev and dlc
+	 */
+	skb_queue_purge(&dev->dlc->tx_queue);
+
+	tty_port_put(&dev->port);
+}
+
+/* we acquire the tty_port reference since it's here the tty is first used
+ * by setting the termios. We also populate the driver_data field and install
+ * the tty port
+ */
+static int rfcomm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct rfcomm_dev *dev;
+	struct rfcomm_dlc *dlc;
+	int err;
+
+	dev = rfcomm_dev_get(tty->index);
+	if (!dev)
+		return -ENODEV;
+
+	dlc = dev->dlc;
+
+	/* Attach TTY and open DLC */
+	rfcomm_dlc_lock(dlc);
+	tty->driver_data = dev;
+	rfcomm_dlc_unlock(dlc);
+	set_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
+
+	/* install the tty_port */
+	err = tty_port_install(&dev->port, driver, tty);
+	if (err) {
+		rfcomm_tty_cleanup(tty);
+		return err;
+	}
+
+	/* take over the tty_port reference if the port was created with the
+	 * flag RFCOMM_RELEASE_ONHUP. This will force the release of the port
+	 * when the last process closes the tty. The behaviour is expected by
+	 * userspace.
+	 */
+	if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
+		set_bit(RFCOMM_TTY_OWNED, &dev->status);
+		tty_port_put(&dev->port);
+	}
+
+	return 0;
+}
+
+static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
+{
+	struct rfcomm_dev *dev = tty->driver_data;
+	int err;
+
+	BT_DBG("tty %p id %d", tty, tty->index);
+
+	BT_DBG("dev %p dst %pMR channel %d opened %d", dev, &dev->dst,
+	       dev->channel, dev->port.count);
+
+	err = tty_port_open(&dev->port, tty, filp);
+	if (err)
+		return err;
+
+	/*
+	 * FIXME: rfcomm should use proper flow control for
+	 * received data. This hack will be unnecessary and can
+	 * be removed when that's implemented
+	 */
+	rfcomm_tty_copy_pending(dev);
+
+	rfcomm_dlc_unthrottle(dev->dlc);
+
+	return 0;
+}
+
+static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
+{
+	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+
+	BT_DBG("tty %p dev %p dlc %p opened %d", tty, dev, dev->dlc,
+						dev->port.count);
+
+	tty_port_close(&dev->port, tty, filp);
+}
+
+static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
+{
+	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+	struct rfcomm_dlc *dlc = dev->dlc;
+	struct sk_buff *skb;
+	int sent = 0, size;
+
+	BT_DBG("tty %p count %d", tty, count);
+
+	while (count) {
+		size = min_t(uint, count, dlc->mtu);
+
+		skb = rfcomm_wmalloc(dev, size + RFCOMM_SKB_RESERVE, GFP_ATOMIC);
+		if (!skb)
+			break;
+
+		skb_reserve(skb, RFCOMM_SKB_HEAD_RESERVE);
+
+		skb_put_data(skb, buf + sent, size);
+
+		rfcomm_dlc_send_noerror(dlc, skb);
+
+		sent  += size;
+		count -= size;
+	}
+
+	return sent;
+}
+
+static int rfcomm_tty_write_room(struct tty_struct *tty)
+{
+	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+	int room = 0;
+
+	if (dev && dev->dlc)
+		room = rfcomm_room(dev);
+
+	BT_DBG("tty %p room %d", tty, room);
+
+	return room;
+}
+
+static int rfcomm_tty_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
+{
+	BT_DBG("tty %p cmd 0x%02x", tty, cmd);
+
+	switch (cmd) {
+	case TCGETS:
+		BT_DBG("TCGETS is not supported");
+		return -ENOIOCTLCMD;
+
+	case TCSETS:
+		BT_DBG("TCSETS is not supported");
+		return -ENOIOCTLCMD;
+
+	case TIOCMIWAIT:
+		BT_DBG("TIOCMIWAIT");
+		break;
+
+	case TIOCSERGETLSR:
+		BT_ERR("TIOCSERGETLSR is not supported");
+		return -ENOIOCTLCMD;
+
+	case TIOCSERCONFIG:
+		BT_ERR("TIOCSERCONFIG is not supported");
+		return -ENOIOCTLCMD;
+
+	default:
+		return -ENOIOCTLCMD;	/* ioctls which we must ignore */
+
+	}
+
+	return -ENOIOCTLCMD;
+}
+
+static void rfcomm_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
+{
+	struct ktermios *new = &tty->termios;
+	int old_baud_rate = tty_termios_baud_rate(old);
+	int new_baud_rate = tty_termios_baud_rate(new);
+
+	u8 baud, data_bits, stop_bits, parity, x_on, x_off;
+	u16 changes = 0;
+
+	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+
+	BT_DBG("tty %p termios %p", tty, old);
+
+	if (!dev || !dev->dlc || !dev->dlc->session)
+		return;
+
+	/* Handle turning off CRTSCTS */
+	if ((old->c_cflag & CRTSCTS) && !(new->c_cflag & CRTSCTS))
+		BT_DBG("Turning off CRTSCTS unsupported");
+
+	/* Parity on/off and when on, odd/even */
+	if (((old->c_cflag & PARENB) != (new->c_cflag & PARENB)) ||
+			((old->c_cflag & PARODD) != (new->c_cflag & PARODD))) {
+		changes |= RFCOMM_RPN_PM_PARITY;
+		BT_DBG("Parity change detected.");
+	}
+
+	/* Mark and space parity are not supported! */
+	if (new->c_cflag & PARENB) {
+		if (new->c_cflag & PARODD) {
+			BT_DBG("Parity is ODD");
+			parity = RFCOMM_RPN_PARITY_ODD;
+		} else {
+			BT_DBG("Parity is EVEN");
+			parity = RFCOMM_RPN_PARITY_EVEN;
+		}
+	} else {
+		BT_DBG("Parity is OFF");
+		parity = RFCOMM_RPN_PARITY_NONE;
+	}
+
+	/* Setting the x_on / x_off characters */
+	if (old->c_cc[VSTOP] != new->c_cc[VSTOP]) {
+		BT_DBG("XOFF custom");
+		x_on = new->c_cc[VSTOP];
+		changes |= RFCOMM_RPN_PM_XON;
+	} else {
+		BT_DBG("XOFF default");
+		x_on = RFCOMM_RPN_XON_CHAR;
+	}
+
+	if (old->c_cc[VSTART] != new->c_cc[VSTART]) {
+		BT_DBG("XON custom");
+		x_off = new->c_cc[VSTART];
+		changes |= RFCOMM_RPN_PM_XOFF;
+	} else {
+		BT_DBG("XON default");
+		x_off = RFCOMM_RPN_XOFF_CHAR;
+	}
+
+	/* Handle setting of stop bits */
+	if ((old->c_cflag & CSTOPB) != (new->c_cflag & CSTOPB))
+		changes |= RFCOMM_RPN_PM_STOP;
+
+	/* POSIX does not support 1.5 stop bits and RFCOMM does not
+	 * support 2 stop bits. So a request for 2 stop bits gets
+	 * translated to 1.5 stop bits */
+	if (new->c_cflag & CSTOPB)
+		stop_bits = RFCOMM_RPN_STOP_15;
+	else
+		stop_bits = RFCOMM_RPN_STOP_1;
+
+	/* Handle number of data bits [5-8] */
+	if ((old->c_cflag & CSIZE) != (new->c_cflag & CSIZE))
+		changes |= RFCOMM_RPN_PM_DATA;
+
+	switch (new->c_cflag & CSIZE) {
+	case CS5:
+		data_bits = RFCOMM_RPN_DATA_5;
+		break;
+	case CS6:
+		data_bits = RFCOMM_RPN_DATA_6;
+		break;
+	case CS7:
+		data_bits = RFCOMM_RPN_DATA_7;
+		break;
+	case CS8:
+		data_bits = RFCOMM_RPN_DATA_8;
+		break;
+	default:
+		data_bits = RFCOMM_RPN_DATA_8;
+		break;
+	}
+
+	/* Handle baudrate settings */
+	if (old_baud_rate != new_baud_rate)
+		changes |= RFCOMM_RPN_PM_BITRATE;
+
+	switch (new_baud_rate) {
+	case 2400:
+		baud = RFCOMM_RPN_BR_2400;
+		break;
+	case 4800:
+		baud = RFCOMM_RPN_BR_4800;
+		break;
+	case 7200:
+		baud = RFCOMM_RPN_BR_7200;
+		break;
+	case 9600:
+		baud = RFCOMM_RPN_BR_9600;
+		break;
+	case 19200:
+		baud = RFCOMM_RPN_BR_19200;
+		break;
+	case 38400:
+		baud = RFCOMM_RPN_BR_38400;
+		break;
+	case 57600:
+		baud = RFCOMM_RPN_BR_57600;
+		break;
+	case 115200:
+		baud = RFCOMM_RPN_BR_115200;
+		break;
+	case 230400:
+		baud = RFCOMM_RPN_BR_230400;
+		break;
+	default:
+		/* 9600 is standard accordinag to the RFCOMM specification */
+		baud = RFCOMM_RPN_BR_9600;
+		break;
+
+	}
+
+	if (changes)
+		rfcomm_send_rpn(dev->dlc->session, 1, dev->dlc->dlci, baud,
+				data_bits, stop_bits, parity,
+				RFCOMM_RPN_FLOW_NONE, x_on, x_off, changes);
+}
+
+static void rfcomm_tty_throttle(struct tty_struct *tty)
+{
+	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+
+	BT_DBG("tty %p dev %p", tty, dev);
+
+	rfcomm_dlc_throttle(dev->dlc);
+}
+
+static void rfcomm_tty_unthrottle(struct tty_struct *tty)
+{
+	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+
+	BT_DBG("tty %p dev %p", tty, dev);
+
+	rfcomm_dlc_unthrottle(dev->dlc);
+}
+
+static int rfcomm_tty_chars_in_buffer(struct tty_struct *tty)
+{
+	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+
+	BT_DBG("tty %p dev %p", tty, dev);
+
+	if (!dev || !dev->dlc)
+		return 0;
+
+	if (!skb_queue_empty(&dev->dlc->tx_queue))
+		return dev->dlc->mtu;
+
+	return 0;
+}
+
+static void rfcomm_tty_flush_buffer(struct tty_struct *tty)
+{
+	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+
+	BT_DBG("tty %p dev %p", tty, dev);
+
+	if (!dev || !dev->dlc)
+		return;
+
+	skb_queue_purge(&dev->dlc->tx_queue);
+	tty_wakeup(tty);
+}
+
+static void rfcomm_tty_send_xchar(struct tty_struct *tty, char ch)
+{
+	BT_DBG("tty %p ch %c", tty, ch);
+}
+
+static void rfcomm_tty_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	BT_DBG("tty %p timeout %d", tty, timeout);
+}
+
+static void rfcomm_tty_hangup(struct tty_struct *tty)
+{
+	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+
+	BT_DBG("tty %p dev %p", tty, dev);
+
+	tty_port_hangup(&dev->port);
+}
+
+static int rfcomm_tty_tiocmget(struct tty_struct *tty)
+{
+	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+
+	BT_DBG("tty %p dev %p", tty, dev);
+
+	return dev->modem_status;
+}
+
+static int rfcomm_tty_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
+{
+	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+	struct rfcomm_dlc *dlc = dev->dlc;
+	u8 v24_sig;
+
+	BT_DBG("tty %p dev %p set 0x%02x clear 0x%02x", tty, dev, set, clear);
+
+	rfcomm_dlc_get_modem_status(dlc, &v24_sig);
+
+	if (set & TIOCM_DSR || set & TIOCM_DTR)
+		v24_sig |= RFCOMM_V24_RTC;
+	if (set & TIOCM_RTS || set & TIOCM_CTS)
+		v24_sig |= RFCOMM_V24_RTR;
+	if (set & TIOCM_RI)
+		v24_sig |= RFCOMM_V24_IC;
+	if (set & TIOCM_CD)
+		v24_sig |= RFCOMM_V24_DV;
+
+	if (clear & TIOCM_DSR || clear & TIOCM_DTR)
+		v24_sig &= ~RFCOMM_V24_RTC;
+	if (clear & TIOCM_RTS || clear & TIOCM_CTS)
+		v24_sig &= ~RFCOMM_V24_RTR;
+	if (clear & TIOCM_RI)
+		v24_sig &= ~RFCOMM_V24_IC;
+	if (clear & TIOCM_CD)
+		v24_sig &= ~RFCOMM_V24_DV;
+
+	rfcomm_dlc_set_modem_status(dlc, v24_sig);
+
+	return 0;
+}
+
+/* ---- TTY structure ---- */
+
+static const struct tty_operations rfcomm_ops = {
+	.open			= rfcomm_tty_open,
+	.close			= rfcomm_tty_close,
+	.write			= rfcomm_tty_write,
+	.write_room		= rfcomm_tty_write_room,
+	.chars_in_buffer	= rfcomm_tty_chars_in_buffer,
+	.flush_buffer		= rfcomm_tty_flush_buffer,
+	.ioctl			= rfcomm_tty_ioctl,
+	.throttle		= rfcomm_tty_throttle,
+	.unthrottle		= rfcomm_tty_unthrottle,
+	.set_termios		= rfcomm_tty_set_termios,
+	.send_xchar		= rfcomm_tty_send_xchar,
+	.hangup			= rfcomm_tty_hangup,
+	.wait_until_sent	= rfcomm_tty_wait_until_sent,
+	.tiocmget		= rfcomm_tty_tiocmget,
+	.tiocmset		= rfcomm_tty_tiocmset,
+	.install                = rfcomm_tty_install,
+	.cleanup                = rfcomm_tty_cleanup,
+};
+
+int __init rfcomm_init_ttys(void)
+{
+	int error;
+
+	rfcomm_tty_driver = alloc_tty_driver(RFCOMM_TTY_PORTS);
+	if (!rfcomm_tty_driver)
+		return -ENOMEM;
+
+	rfcomm_tty_driver->driver_name	= "rfcomm";
+	rfcomm_tty_driver->name		= "rfcomm";
+	rfcomm_tty_driver->major	= RFCOMM_TTY_MAJOR;
+	rfcomm_tty_driver->minor_start	= RFCOMM_TTY_MINOR;
+	rfcomm_tty_driver->type		= TTY_DRIVER_TYPE_SERIAL;
+	rfcomm_tty_driver->subtype	= SERIAL_TYPE_NORMAL;
+	rfcomm_tty_driver->flags	= TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
+	rfcomm_tty_driver->init_termios	= tty_std_termios;
+	rfcomm_tty_driver->init_termios.c_cflag	= B9600 | CS8 | CREAD | HUPCL;
+	rfcomm_tty_driver->init_termios.c_lflag &= ~ICANON;
+	tty_set_operations(rfcomm_tty_driver, &rfcomm_ops);
+
+	error = tty_register_driver(rfcomm_tty_driver);
+	if (error) {
+		BT_ERR("Can't register RFCOMM TTY driver");
+		put_tty_driver(rfcomm_tty_driver);
+		return error;
+	}
+
+	BT_INFO("RFCOMM TTY layer initialized");
+
+	return 0;
+}
+
+void rfcomm_cleanup_ttys(void)
+{
+	tty_unregister_driver(rfcomm_tty_driver);
+	put_tty_driver(rfcomm_tty_driver);
+}