Adding upstream version 6.1.76.upstream/6.1.76

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

1 files changed, 8657 insertions, 0 deletions

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
new file mode 100644
index 000000000..4c5793053
--- /dev/null
+++ b/net/bluetooth/l2cap_core.c
@@ -0,0 +1,8657 @@
+/*
+   BlueZ - Bluetooth protocol stack for Linux
+   Copyright (C) 2000-2001 Qualcomm Incorporated
+   Copyright (C) 2009-2010 Gustavo F. Padovan <gustavo@padovan.org>
+   Copyright (C) 2010 Google Inc.
+   Copyright (C) 2011 ProFUSION Embedded Systems
+   Copyright (c) 2012 Code Aurora Forum.  All rights reserved.
+
+   Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>
+
+   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 L2CAP core. */
+
+#include <linux/module.h>
+
+#include <linux/debugfs.h>
+#include <linux/crc16.h>
+#include <linux/filter.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+#include <net/bluetooth/l2cap.h>
+
+#include "smp.h"
+#include "a2mp.h"
+#include "amp.h"
+
+#define LE_FLOWCTL_MAX_CREDITS 65535
+
+bool disable_ertm;
+bool enable_ecred;
+
+static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN | L2CAP_FEAT_UCD;
+
+static LIST_HEAD(chan_list);
+static DEFINE_RWLOCK(chan_list_lock);
+
+static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn,
+				       u8 code, u8 ident, u16 dlen, void *data);
+static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
+			   void *data);
+static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size);
+static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err);
+
+static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
+		     struct sk_buff_head *skbs, u8 event);
+static void l2cap_retrans_timeout(struct work_struct *work);
+static void l2cap_monitor_timeout(struct work_struct *work);
+static void l2cap_ack_timeout(struct work_struct *work);
+
+static inline u8 bdaddr_type(u8 link_type, u8 bdaddr_type)
+{
+	if (link_type == LE_LINK) {
+		if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
+			return BDADDR_LE_PUBLIC;
+		else
+			return BDADDR_LE_RANDOM;
+	}
+
+	return BDADDR_BREDR;
+}
+
+static inline u8 bdaddr_src_type(struct hci_conn *hcon)
+{
+	return bdaddr_type(hcon->type, hcon->src_type);
+}
+
+static inline u8 bdaddr_dst_type(struct hci_conn *hcon)
+{
+	return bdaddr_type(hcon->type, hcon->dst_type);
+}
+
+/* ---- L2CAP channels ---- */
+
+static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
+						   u16 cid)
+{
+	struct l2cap_chan *c;
+
+	list_for_each_entry(c, &conn->chan_l, list) {
+		if (c->dcid == cid)
+			return c;
+	}
+	return NULL;
+}
+
+static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn,
+						   u16 cid)
+{
+	struct l2cap_chan *c;
+
+	list_for_each_entry(c, &conn->chan_l, list) {
+		if (c->scid == cid)
+			return c;
+	}
+	return NULL;
+}
+
+/* Find channel with given SCID.
+ * Returns a reference locked channel.
+ */
+static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn,
+						 u16 cid)
+{
+	struct l2cap_chan *c;
+
+	mutex_lock(&conn->chan_lock);
+	c = __l2cap_get_chan_by_scid(conn, cid);
+	if (c) {
+		/* Only lock if chan reference is not 0 */
+		c = l2cap_chan_hold_unless_zero(c);
+		if (c)
+			l2cap_chan_lock(c);
+	}
+	mutex_unlock(&conn->chan_lock);
+
+	return c;
+}
+
+/* Find channel with given DCID.
+ * Returns a reference locked channel.
+ */
+static struct l2cap_chan *l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
+						 u16 cid)
+{
+	struct l2cap_chan *c;
+
+	mutex_lock(&conn->chan_lock);
+	c = __l2cap_get_chan_by_dcid(conn, cid);
+	if (c) {
+		/* Only lock if chan reference is not 0 */
+		c = l2cap_chan_hold_unless_zero(c);
+		if (c)
+			l2cap_chan_lock(c);
+	}
+	mutex_unlock(&conn->chan_lock);
+
+	return c;
+}
+
+static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn,
+						    u8 ident)
+{
+	struct l2cap_chan *c;
+
+	list_for_each_entry(c, &conn->chan_l, list) {
+		if (c->ident == ident)
+			return c;
+	}
+	return NULL;
+}
+
+static struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_conn *conn,
+						  u8 ident)
+{
+	struct l2cap_chan *c;
+
+	mutex_lock(&conn->chan_lock);
+	c = __l2cap_get_chan_by_ident(conn, ident);
+	if (c) {
+		/* Only lock if chan reference is not 0 */
+		c = l2cap_chan_hold_unless_zero(c);
+		if (c)
+			l2cap_chan_lock(c);
+	}
+	mutex_unlock(&conn->chan_lock);
+
+	return c;
+}
+
+static struct l2cap_chan *__l2cap_global_chan_by_addr(__le16 psm, bdaddr_t *src,
+						      u8 src_type)
+{
+	struct l2cap_chan *c;
+
+	list_for_each_entry(c, &chan_list, global_l) {
+		if (src_type == BDADDR_BREDR && c->src_type != BDADDR_BREDR)
+			continue;
+
+		if (src_type != BDADDR_BREDR && c->src_type == BDADDR_BREDR)
+			continue;
+
+		if (c->sport == psm && !bacmp(&c->src, src))
+			return c;
+	}
+	return NULL;
+}
+
+int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm)
+{
+	int err;
+
+	write_lock(&chan_list_lock);
+
+	if (psm && __l2cap_global_chan_by_addr(psm, src, chan->src_type)) {
+		err = -EADDRINUSE;
+		goto done;
+	}
+
+	if (psm) {
+		chan->psm = psm;
+		chan->sport = psm;
+		err = 0;
+	} else {
+		u16 p, start, end, incr;
+
+		if (chan->src_type == BDADDR_BREDR) {
+			start = L2CAP_PSM_DYN_START;
+			end = L2CAP_PSM_AUTO_END;
+			incr = 2;
+		} else {
+			start = L2CAP_PSM_LE_DYN_START;
+			end = L2CAP_PSM_LE_DYN_END;
+			incr = 1;
+		}
+
+		err = -EINVAL;
+		for (p = start; p <= end; p += incr)
+			if (!__l2cap_global_chan_by_addr(cpu_to_le16(p), src,
+							 chan->src_type)) {
+				chan->psm   = cpu_to_le16(p);
+				chan->sport = cpu_to_le16(p);
+				err = 0;
+				break;
+			}
+	}
+
+done:
+	write_unlock(&chan_list_lock);
+	return err;
+}
+EXPORT_SYMBOL_GPL(l2cap_add_psm);
+
+int l2cap_add_scid(struct l2cap_chan *chan,  __u16 scid)
+{
+	write_lock(&chan_list_lock);
+
+	/* Override the defaults (which are for conn-oriented) */
+	chan->omtu = L2CAP_DEFAULT_MTU;
+	chan->chan_type = L2CAP_CHAN_FIXED;
+
+	chan->scid = scid;
+
+	write_unlock(&chan_list_lock);
+
+	return 0;
+}
+
+static u16 l2cap_alloc_cid(struct l2cap_conn *conn)
+{
+	u16 cid, dyn_end;
+
+	if (conn->hcon->type == LE_LINK)
+		dyn_end = L2CAP_CID_LE_DYN_END;
+	else
+		dyn_end = L2CAP_CID_DYN_END;
+
+	for (cid = L2CAP_CID_DYN_START; cid <= dyn_end; cid++) {
+		if (!__l2cap_get_chan_by_scid(conn, cid))
+			return cid;
+	}
+
+	return 0;
+}
+
+static void l2cap_state_change(struct l2cap_chan *chan, int state)
+{
+	BT_DBG("chan %p %s -> %s", chan, state_to_string(chan->state),
+	       state_to_string(state));
+
+	chan->state = state;
+	chan->ops->state_change(chan, state, 0);
+}
+
+static inline void l2cap_state_change_and_error(struct l2cap_chan *chan,
+						int state, int err)
+{
+	chan->state = state;
+	chan->ops->state_change(chan, chan->state, err);
+}
+
+static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err)
+{
+	chan->ops->state_change(chan, chan->state, err);
+}
+
+static void __set_retrans_timer(struct l2cap_chan *chan)
+{
+	if (!delayed_work_pending(&chan->monitor_timer) &&
+	    chan->retrans_timeout) {
+		l2cap_set_timer(chan, &chan->retrans_timer,
+				msecs_to_jiffies(chan->retrans_timeout));
+	}
+}
+
+static void __set_monitor_timer(struct l2cap_chan *chan)
+{
+	__clear_retrans_timer(chan);
+	if (chan->monitor_timeout) {
+		l2cap_set_timer(chan, &chan->monitor_timer,
+				msecs_to_jiffies(chan->monitor_timeout));
+	}
+}
+
+static struct sk_buff *l2cap_ertm_seq_in_queue(struct sk_buff_head *head,
+					       u16 seq)
+{
+	struct sk_buff *skb;
+
+	skb_queue_walk(head, skb) {
+		if (bt_cb(skb)->l2cap.txseq == seq)
+			return skb;
+	}
+
+	return NULL;
+}
+
+/* ---- L2CAP sequence number lists ---- */
+
+/* For ERTM, ordered lists of sequence numbers must be tracked for
+ * SREJ requests that are received and for frames that are to be
+ * retransmitted. These seq_list functions implement a singly-linked
+ * list in an array, where membership in the list can also be checked
+ * in constant time. Items can also be added to the tail of the list
+ * and removed from the head in constant time, without further memory
+ * allocs or frees.
+ */
+
+static int l2cap_seq_list_init(struct l2cap_seq_list *seq_list, u16 size)
+{
+	size_t alloc_size, i;
+
+	/* Allocated size is a power of 2 to map sequence numbers
+	 * (which may be up to 14 bits) in to a smaller array that is
+	 * sized for the negotiated ERTM transmit windows.
+	 */
+	alloc_size = roundup_pow_of_two(size);
+
+	seq_list->list = kmalloc_array(alloc_size, sizeof(u16), GFP_KERNEL);
+	if (!seq_list->list)
+		return -ENOMEM;
+
+	seq_list->mask = alloc_size - 1;
+	seq_list->head = L2CAP_SEQ_LIST_CLEAR;
+	seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
+	for (i = 0; i < alloc_size; i++)
+		seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
+
+	return 0;
+}
+
+static inline void l2cap_seq_list_free(struct l2cap_seq_list *seq_list)
+{
+	kfree(seq_list->list);
+}
+
+static inline bool l2cap_seq_list_contains(struct l2cap_seq_list *seq_list,
+					   u16 seq)
+{
+	/* Constant-time check for list membership */
+	return seq_list->list[seq & seq_list->mask] != L2CAP_SEQ_LIST_CLEAR;
+}
+
+static inline u16 l2cap_seq_list_pop(struct l2cap_seq_list *seq_list)
+{
+	u16 seq = seq_list->head;
+	u16 mask = seq_list->mask;
+
+	seq_list->head = seq_list->list[seq & mask];
+	seq_list->list[seq & mask] = L2CAP_SEQ_LIST_CLEAR;
+
+	if (seq_list->head == L2CAP_SEQ_LIST_TAIL) {
+		seq_list->head = L2CAP_SEQ_LIST_CLEAR;
+		seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
+	}
+
+	return seq;
+}
+
+static void l2cap_seq_list_clear(struct l2cap_seq_list *seq_list)
+{
+	u16 i;
+
+	if (seq_list->head == L2CAP_SEQ_LIST_CLEAR)
+		return;
+
+	for (i = 0; i <= seq_list->mask; i++)
+		seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
+
+	seq_list->head = L2CAP_SEQ_LIST_CLEAR;
+	seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
+}
+
+static void l2cap_seq_list_append(struct l2cap_seq_list *seq_list, u16 seq)
+{
+	u16 mask = seq_list->mask;
+
+	/* All appends happen in constant time */
+
+	if (seq_list->list[seq & mask] != L2CAP_SEQ_LIST_CLEAR)
+		return;
+
+	if (seq_list->tail == L2CAP_SEQ_LIST_CLEAR)
+		seq_list->head = seq;
+	else
+		seq_list->list[seq_list->tail & mask] = seq;
+
+	seq_list->tail = seq;
+	seq_list->list[seq & mask] = L2CAP_SEQ_LIST_TAIL;
+}
+
+static void l2cap_chan_timeout(struct work_struct *work)
+{
+	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
+					       chan_timer.work);
+	struct l2cap_conn *conn = chan->conn;
+	int reason;
+
+	BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
+
+	mutex_lock(&conn->chan_lock);
+	/* __set_chan_timer() calls l2cap_chan_hold(chan) while scheduling
+	 * this work. No need to call l2cap_chan_hold(chan) here again.
+	 */
+	l2cap_chan_lock(chan);
+
+	if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG)
+		reason = ECONNREFUSED;
+	else if (chan->state == BT_CONNECT &&
+		 chan->sec_level != BT_SECURITY_SDP)
+		reason = ECONNREFUSED;
+	else
+		reason = ETIMEDOUT;
+
+	l2cap_chan_close(chan, reason);
+
+	chan->ops->close(chan);
+
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+
+	mutex_unlock(&conn->chan_lock);
+}
+
+struct l2cap_chan *l2cap_chan_create(void)
+{
+	struct l2cap_chan *chan;
+
+	chan = kzalloc(sizeof(*chan), GFP_ATOMIC);
+	if (!chan)
+		return NULL;
+
+	skb_queue_head_init(&chan->tx_q);
+	skb_queue_head_init(&chan->srej_q);
+	mutex_init(&chan->lock);
+
+	/* Set default lock nesting level */
+	atomic_set(&chan->nesting, L2CAP_NESTING_NORMAL);
+
+	write_lock(&chan_list_lock);
+	list_add(&chan->global_l, &chan_list);
+	write_unlock(&chan_list_lock);
+
+	INIT_DELAYED_WORK(&chan->chan_timer, l2cap_chan_timeout);
+	INIT_DELAYED_WORK(&chan->retrans_timer, l2cap_retrans_timeout);
+	INIT_DELAYED_WORK(&chan->monitor_timer, l2cap_monitor_timeout);
+	INIT_DELAYED_WORK(&chan->ack_timer, l2cap_ack_timeout);
+
+	chan->state = BT_OPEN;
+
+	kref_init(&chan->kref);
+
+	/* This flag is cleared in l2cap_chan_ready() */
+	set_bit(CONF_NOT_COMPLETE, &chan->conf_state);
+
+	BT_DBG("chan %p", chan);
+
+	return chan;
+}
+EXPORT_SYMBOL_GPL(l2cap_chan_create);
+
+static void l2cap_chan_destroy(struct kref *kref)
+{
+	struct l2cap_chan *chan = container_of(kref, struct l2cap_chan, kref);
+
+	BT_DBG("chan %p", chan);
+
+	write_lock(&chan_list_lock);
+	list_del(&chan->global_l);
+	write_unlock(&chan_list_lock);
+
+	kfree(chan);
+}
+
+void l2cap_chan_hold(struct l2cap_chan *c)
+{
+	BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref));
+
+	kref_get(&c->kref);
+}
+
+struct l2cap_chan *l2cap_chan_hold_unless_zero(struct l2cap_chan *c)
+{
+	BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref));
+
+	if (!kref_get_unless_zero(&c->kref))
+		return NULL;
+
+	return c;
+}
+
+void l2cap_chan_put(struct l2cap_chan *c)
+{
+	BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref));
+
+	kref_put(&c->kref, l2cap_chan_destroy);
+}
+EXPORT_SYMBOL_GPL(l2cap_chan_put);
+
+void l2cap_chan_set_defaults(struct l2cap_chan *chan)
+{
+	chan->fcs  = L2CAP_FCS_CRC16;
+	chan->max_tx = L2CAP_DEFAULT_MAX_TX;
+	chan->tx_win = L2CAP_DEFAULT_TX_WINDOW;
+	chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
+	chan->remote_max_tx = chan->max_tx;
+	chan->remote_tx_win = chan->tx_win;
+	chan->ack_win = L2CAP_DEFAULT_TX_WINDOW;
+	chan->sec_level = BT_SECURITY_LOW;
+	chan->flush_to = L2CAP_DEFAULT_FLUSH_TO;
+	chan->retrans_timeout = L2CAP_DEFAULT_RETRANS_TO;
+	chan->monitor_timeout = L2CAP_DEFAULT_MONITOR_TO;
+
+	chan->conf_state = 0;
+	set_bit(CONF_NOT_COMPLETE, &chan->conf_state);
+
+	set_bit(FLAG_FORCE_ACTIVE, &chan->flags);
+}
+EXPORT_SYMBOL_GPL(l2cap_chan_set_defaults);
+
+static void l2cap_le_flowctl_init(struct l2cap_chan *chan, u16 tx_credits)
+{
+	chan->sdu = NULL;
+	chan->sdu_last_frag = NULL;
+	chan->sdu_len = 0;
+	chan->tx_credits = tx_credits;
+	/* Derive MPS from connection MTU to stop HCI fragmentation */
+	chan->mps = min_t(u16, chan->imtu, chan->conn->mtu - L2CAP_HDR_SIZE);
+	/* Give enough credits for a full packet */
+	chan->rx_credits = (chan->imtu / chan->mps) + 1;
+
+	skb_queue_head_init(&chan->tx_q);
+}
+
+static void l2cap_ecred_init(struct l2cap_chan *chan, u16 tx_credits)
+{
+	l2cap_le_flowctl_init(chan, tx_credits);
+
+	/* L2CAP implementations shall support a minimum MPS of 64 octets */
+	if (chan->mps < L2CAP_ECRED_MIN_MPS) {
+		chan->mps = L2CAP_ECRED_MIN_MPS;
+		chan->rx_credits = (chan->imtu / chan->mps) + 1;
+	}
+}
+
+void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
+{
+	BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn,
+	       __le16_to_cpu(chan->psm), chan->dcid);
+
+	conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
+
+	chan->conn = conn;
+
+	switch (chan->chan_type) {
+	case L2CAP_CHAN_CONN_ORIENTED:
+		/* Alloc CID for connection-oriented socket */
+		chan->scid = l2cap_alloc_cid(conn);
+		if (conn->hcon->type == ACL_LINK)
+			chan->omtu = L2CAP_DEFAULT_MTU;
+		break;
+
+	case L2CAP_CHAN_CONN_LESS:
+		/* Connectionless socket */
+		chan->scid = L2CAP_CID_CONN_LESS;
+		chan->dcid = L2CAP_CID_CONN_LESS;
+		chan->omtu = L2CAP_DEFAULT_MTU;
+		break;
+
+	case L2CAP_CHAN_FIXED:
+		/* Caller will set CID and CID specific MTU values */
+		break;
+
+	default:
+		/* Raw socket can send/recv signalling messages only */
+		chan->scid = L2CAP_CID_SIGNALING;
+		chan->dcid = L2CAP_CID_SIGNALING;
+		chan->omtu = L2CAP_DEFAULT_MTU;
+	}
+
+	chan->local_id		= L2CAP_BESTEFFORT_ID;
+	chan->local_stype	= L2CAP_SERV_BESTEFFORT;
+	chan->local_msdu	= L2CAP_DEFAULT_MAX_SDU_SIZE;
+	chan->local_sdu_itime	= L2CAP_DEFAULT_SDU_ITIME;
+	chan->local_acc_lat	= L2CAP_DEFAULT_ACC_LAT;
+	chan->local_flush_to	= L2CAP_EFS_DEFAULT_FLUSH_TO;
+
+	l2cap_chan_hold(chan);
+
+	/* Only keep a reference for fixed channels if they requested it */
+	if (chan->chan_type != L2CAP_CHAN_FIXED ||
+	    test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
+		hci_conn_hold(conn->hcon);
+
+	list_add(&chan->list, &conn->chan_l);
+}
+
+void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
+{
+	mutex_lock(&conn->chan_lock);
+	__l2cap_chan_add(conn, chan);
+	mutex_unlock(&conn->chan_lock);
+}
+
+void l2cap_chan_del(struct l2cap_chan *chan, int err)
+{
+	struct l2cap_conn *conn = chan->conn;
+
+	__clear_chan_timer(chan);
+
+	BT_DBG("chan %p, conn %p, err %d, state %s", chan, conn, err,
+	       state_to_string(chan->state));
+
+	chan->ops->teardown(chan, err);
+
+	if (conn) {
+		struct amp_mgr *mgr = conn->hcon->amp_mgr;
+		/* Delete from channel list */
+		list_del(&chan->list);
+
+		l2cap_chan_put(chan);
+
+		chan->conn = NULL;
+
+		/* Reference was only held for non-fixed channels or
+		 * fixed channels that explicitly requested it using the
+		 * FLAG_HOLD_HCI_CONN flag.
+		 */
+		if (chan->chan_type != L2CAP_CHAN_FIXED ||
+		    test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
+			hci_conn_drop(conn->hcon);
+
+		if (mgr && mgr->bredr_chan == chan)
+			mgr->bredr_chan = NULL;
+	}
+
+	if (chan->hs_hchan) {
+		struct hci_chan *hs_hchan = chan->hs_hchan;
+
+		BT_DBG("chan %p disconnect hs_hchan %p", chan, hs_hchan);
+		amp_disconnect_logical_link(hs_hchan);
+	}
+
+	if (test_bit(CONF_NOT_COMPLETE, &chan->conf_state))
+		return;
+
+	switch (chan->mode) {
+	case L2CAP_MODE_BASIC:
+		break;
+
+	case L2CAP_MODE_LE_FLOWCTL:
+	case L2CAP_MODE_EXT_FLOWCTL:
+		skb_queue_purge(&chan->tx_q);
+		break;
+
+	case L2CAP_MODE_ERTM:
+		__clear_retrans_timer(chan);
+		__clear_monitor_timer(chan);
+		__clear_ack_timer(chan);
+
+		skb_queue_purge(&chan->srej_q);
+
+		l2cap_seq_list_free(&chan->srej_list);
+		l2cap_seq_list_free(&chan->retrans_list);
+		fallthrough;
+
+	case L2CAP_MODE_STREAMING:
+		skb_queue_purge(&chan->tx_q);
+		break;
+	}
+}
+EXPORT_SYMBOL_GPL(l2cap_chan_del);
+
+static void __l2cap_chan_list_id(struct l2cap_conn *conn, u16 id,
+				 l2cap_chan_func_t func, void *data)
+{
+	struct l2cap_chan *chan, *l;
+
+	list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
+		if (chan->ident == id)
+			func(chan, data);
+	}
+}
+
+static void __l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
+			      void *data)
+{
+	struct l2cap_chan *chan;
+
+	list_for_each_entry(chan, &conn->chan_l, list) {
+		func(chan, data);
+	}
+}
+
+void l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
+		     void *data)
+{
+	if (!conn)
+		return;
+
+	mutex_lock(&conn->chan_lock);
+	__l2cap_chan_list(conn, func, data);
+	mutex_unlock(&conn->chan_lock);
+}
+
+EXPORT_SYMBOL_GPL(l2cap_chan_list);
+
+static void l2cap_conn_update_id_addr(struct work_struct *work)
+{
+	struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
+					       id_addr_update_work);
+	struct hci_conn *hcon = conn->hcon;
+	struct l2cap_chan *chan;
+
+	mutex_lock(&conn->chan_lock);
+
+	list_for_each_entry(chan, &conn->chan_l, list) {
+		l2cap_chan_lock(chan);
+		bacpy(&chan->dst, &hcon->dst);
+		chan->dst_type = bdaddr_dst_type(hcon);
+		l2cap_chan_unlock(chan);
+	}
+
+	mutex_unlock(&conn->chan_lock);
+}
+
+static void l2cap_chan_le_connect_reject(struct l2cap_chan *chan)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct l2cap_le_conn_rsp rsp;
+	u16 result;
+
+	if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
+		result = L2CAP_CR_LE_AUTHORIZATION;
+	else
+		result = L2CAP_CR_LE_BAD_PSM;
+
+	l2cap_state_change(chan, BT_DISCONN);
+
+	rsp.dcid    = cpu_to_le16(chan->scid);
+	rsp.mtu     = cpu_to_le16(chan->imtu);
+	rsp.mps     = cpu_to_le16(chan->mps);
+	rsp.credits = cpu_to_le16(chan->rx_credits);
+	rsp.result  = cpu_to_le16(result);
+
+	l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
+		       &rsp);
+}
+
+static void l2cap_chan_ecred_connect_reject(struct l2cap_chan *chan)
+{
+	l2cap_state_change(chan, BT_DISCONN);
+
+	__l2cap_ecred_conn_rsp_defer(chan);
+}
+
+static void l2cap_chan_connect_reject(struct l2cap_chan *chan)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct l2cap_conn_rsp rsp;
+	u16 result;
+
+	if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
+		result = L2CAP_CR_SEC_BLOCK;
+	else
+		result = L2CAP_CR_BAD_PSM;
+
+	l2cap_state_change(chan, BT_DISCONN);
+
+	rsp.scid   = cpu_to_le16(chan->dcid);
+	rsp.dcid   = cpu_to_le16(chan->scid);
+	rsp.result = cpu_to_le16(result);
+	rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
+
+	l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, sizeof(rsp), &rsp);
+}
+
+void l2cap_chan_close(struct l2cap_chan *chan, int reason)
+{
+	struct l2cap_conn *conn = chan->conn;
+
+	BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
+
+	switch (chan->state) {
+	case BT_LISTEN:
+		chan->ops->teardown(chan, 0);
+		break;
+
+	case BT_CONNECTED:
+	case BT_CONFIG:
+		if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
+			__set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
+			l2cap_send_disconn_req(chan, reason);
+		} else
+			l2cap_chan_del(chan, reason);
+		break;
+
+	case BT_CONNECT2:
+		if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
+			if (conn->hcon->type == ACL_LINK)
+				l2cap_chan_connect_reject(chan);
+			else if (conn->hcon->type == LE_LINK) {
+				switch (chan->mode) {
+				case L2CAP_MODE_LE_FLOWCTL:
+					l2cap_chan_le_connect_reject(chan);
+					break;
+				case L2CAP_MODE_EXT_FLOWCTL:
+					l2cap_chan_ecred_connect_reject(chan);
+					return;
+				}
+			}
+		}
+
+		l2cap_chan_del(chan, reason);
+		break;
+
+	case BT_CONNECT:
+	case BT_DISCONN:
+		l2cap_chan_del(chan, reason);
+		break;
+
+	default:
+		chan->ops->teardown(chan, 0);
+		break;
+	}
+}
+EXPORT_SYMBOL(l2cap_chan_close);
+
+static inline u8 l2cap_get_auth_type(struct l2cap_chan *chan)
+{
+	switch (chan->chan_type) {
+	case L2CAP_CHAN_RAW:
+		switch (chan->sec_level) {
+		case BT_SECURITY_HIGH:
+		case BT_SECURITY_FIPS:
+			return HCI_AT_DEDICATED_BONDING_MITM;
+		case BT_SECURITY_MEDIUM:
+			return HCI_AT_DEDICATED_BONDING;
+		default:
+			return HCI_AT_NO_BONDING;
+		}
+		break;
+	case L2CAP_CHAN_CONN_LESS:
+		if (chan->psm == cpu_to_le16(L2CAP_PSM_3DSP)) {
+			if (chan->sec_level == BT_SECURITY_LOW)
+				chan->sec_level = BT_SECURITY_SDP;
+		}
+		if (chan->sec_level == BT_SECURITY_HIGH ||
+		    chan->sec_level == BT_SECURITY_FIPS)
+			return HCI_AT_NO_BONDING_MITM;
+		else
+			return HCI_AT_NO_BONDING;
+		break;
+	case L2CAP_CHAN_CONN_ORIENTED:
+		if (chan->psm == cpu_to_le16(L2CAP_PSM_SDP)) {
+			if (chan->sec_level == BT_SECURITY_LOW)
+				chan->sec_level = BT_SECURITY_SDP;
+
+			if (chan->sec_level == BT_SECURITY_HIGH ||
+			    chan->sec_level == BT_SECURITY_FIPS)
+				return HCI_AT_NO_BONDING_MITM;
+			else
+				return HCI_AT_NO_BONDING;
+		}
+		fallthrough;
+
+	default:
+		switch (chan->sec_level) {
+		case BT_SECURITY_HIGH:
+		case BT_SECURITY_FIPS:
+			return HCI_AT_GENERAL_BONDING_MITM;
+		case BT_SECURITY_MEDIUM:
+			return HCI_AT_GENERAL_BONDING;
+		default:
+			return HCI_AT_NO_BONDING;
+		}
+		break;
+	}
+}
+
+/* Service level security */
+int l2cap_chan_check_security(struct l2cap_chan *chan, bool initiator)
+{
+	struct l2cap_conn *conn = chan->conn;
+	__u8 auth_type;
+
+	if (conn->hcon->type == LE_LINK)
+		return smp_conn_security(conn->hcon, chan->sec_level);
+
+	auth_type = l2cap_get_auth_type(chan);
+
+	return hci_conn_security(conn->hcon, chan->sec_level, auth_type,
+				 initiator);
+}
+
+static u8 l2cap_get_ident(struct l2cap_conn *conn)
+{
+	u8 id;
+
+	/* Get next available identificator.
+	 *    1 - 128 are used by kernel.
+	 *  129 - 199 are reserved.
+	 *  200 - 254 are used by utilities like l2ping, etc.
+	 */
+
+	mutex_lock(&conn->ident_lock);
+
+	if (++conn->tx_ident > 128)
+		conn->tx_ident = 1;
+
+	id = conn->tx_ident;
+
+	mutex_unlock(&conn->ident_lock);
+
+	return id;
+}
+
+static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
+			   void *data)
+{
+	struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data);
+	u8 flags;
+
+	BT_DBG("code 0x%2.2x", code);
+
+	if (!skb)
+		return;
+
+	/* Use NO_FLUSH if supported or we have an LE link (which does
+	 * not support auto-flushing packets) */
+	if (lmp_no_flush_capable(conn->hcon->hdev) ||
+	    conn->hcon->type == LE_LINK)
+		flags = ACL_START_NO_FLUSH;
+	else
+		flags = ACL_START;
+
+	bt_cb(skb)->force_active = BT_POWER_FORCE_ACTIVE_ON;
+	skb->priority = HCI_PRIO_MAX;
+
+	hci_send_acl(conn->hchan, skb, flags);
+}
+
+static bool __chan_is_moving(struct l2cap_chan *chan)
+{
+	return chan->move_state != L2CAP_MOVE_STABLE &&
+	       chan->move_state != L2CAP_MOVE_WAIT_PREPARE;
+}
+
+static void l2cap_do_send(struct l2cap_chan *chan, struct sk_buff *skb)
+{
+	struct hci_conn *hcon = chan->conn->hcon;
+	u16 flags;
+
+	BT_DBG("chan %p, skb %p len %d priority %u", chan, skb, skb->len,
+	       skb->priority);
+
+	if (chan->hs_hcon && !__chan_is_moving(chan)) {
+		if (chan->hs_hchan)
+			hci_send_acl(chan->hs_hchan, skb, ACL_COMPLETE);
+		else
+			kfree_skb(skb);
+
+		return;
+	}
+
+	/* Use NO_FLUSH for LE links (where this is the only option) or
+	 * if the BR/EDR link supports it and flushing has not been
+	 * explicitly requested (through FLAG_FLUSHABLE).
+	 */
+	if (hcon->type == LE_LINK ||
+	    (!test_bit(FLAG_FLUSHABLE, &chan->flags) &&
+	     lmp_no_flush_capable(hcon->hdev)))
+		flags = ACL_START_NO_FLUSH;
+	else
+		flags = ACL_START;
+
+	bt_cb(skb)->force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags);
+	hci_send_acl(chan->conn->hchan, skb, flags);
+}
+
+static void __unpack_enhanced_control(u16 enh, struct l2cap_ctrl *control)
+{
+	control->reqseq = (enh & L2CAP_CTRL_REQSEQ) >> L2CAP_CTRL_REQSEQ_SHIFT;
+	control->final = (enh & L2CAP_CTRL_FINAL) >> L2CAP_CTRL_FINAL_SHIFT;
+
+	if (enh & L2CAP_CTRL_FRAME_TYPE) {
+		/* S-Frame */
+		control->sframe = 1;
+		control->poll = (enh & L2CAP_CTRL_POLL) >> L2CAP_CTRL_POLL_SHIFT;
+		control->super = (enh & L2CAP_CTRL_SUPERVISE) >> L2CAP_CTRL_SUPER_SHIFT;
+
+		control->sar = 0;
+		control->txseq = 0;
+	} else {
+		/* I-Frame */
+		control->sframe = 0;
+		control->sar = (enh & L2CAP_CTRL_SAR) >> L2CAP_CTRL_SAR_SHIFT;
+		control->txseq = (enh & L2CAP_CTRL_TXSEQ) >> L2CAP_CTRL_TXSEQ_SHIFT;
+
+		control->poll = 0;
+		control->super = 0;
+	}
+}
+
+static void __unpack_extended_control(u32 ext, struct l2cap_ctrl *control)
+{
+	control->reqseq = (ext & L2CAP_EXT_CTRL_REQSEQ) >> L2CAP_EXT_CTRL_REQSEQ_SHIFT;
+	control->final = (ext & L2CAP_EXT_CTRL_FINAL) >> L2CAP_EXT_CTRL_FINAL_SHIFT;
+
+	if (ext & L2CAP_EXT_CTRL_FRAME_TYPE) {
+		/* S-Frame */
+		control->sframe = 1;
+		control->poll = (ext & L2CAP_EXT_CTRL_POLL) >> L2CAP_EXT_CTRL_POLL_SHIFT;
+		control->super = (ext & L2CAP_EXT_CTRL_SUPERVISE) >> L2CAP_EXT_CTRL_SUPER_SHIFT;
+
+		control->sar = 0;
+		control->txseq = 0;
+	} else {
+		/* I-Frame */
+		control->sframe = 0;
+		control->sar = (ext & L2CAP_EXT_CTRL_SAR) >> L2CAP_EXT_CTRL_SAR_SHIFT;
+		control->txseq = (ext & L2CAP_EXT_CTRL_TXSEQ) >> L2CAP_EXT_CTRL_TXSEQ_SHIFT;
+
+		control->poll = 0;
+		control->super = 0;
+	}
+}
+
+static inline void __unpack_control(struct l2cap_chan *chan,
+				    struct sk_buff *skb)
+{
+	if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
+		__unpack_extended_control(get_unaligned_le32(skb->data),
+					  &bt_cb(skb)->l2cap);
+		skb_pull(skb, L2CAP_EXT_CTRL_SIZE);
+	} else {
+		__unpack_enhanced_control(get_unaligned_le16(skb->data),
+					  &bt_cb(skb)->l2cap);
+		skb_pull(skb, L2CAP_ENH_CTRL_SIZE);
+	}
+}
+
+static u32 __pack_extended_control(struct l2cap_ctrl *control)
+{
+	u32 packed;
+
+	packed = control->reqseq << L2CAP_EXT_CTRL_REQSEQ_SHIFT;
+	packed |= control->final << L2CAP_EXT_CTRL_FINAL_SHIFT;
+
+	if (control->sframe) {
+		packed |= control->poll << L2CAP_EXT_CTRL_POLL_SHIFT;
+		packed |= control->super << L2CAP_EXT_CTRL_SUPER_SHIFT;
+		packed |= L2CAP_EXT_CTRL_FRAME_TYPE;
+	} else {
+		packed |= control->sar << L2CAP_EXT_CTRL_SAR_SHIFT;
+		packed |= control->txseq << L2CAP_EXT_CTRL_TXSEQ_SHIFT;
+	}
+
+	return packed;
+}
+
+static u16 __pack_enhanced_control(struct l2cap_ctrl *control)
+{
+	u16 packed;
+
+	packed = control->reqseq << L2CAP_CTRL_REQSEQ_SHIFT;
+	packed |= control->final << L2CAP_CTRL_FINAL_SHIFT;
+
+	if (control->sframe) {
+		packed |= control->poll << L2CAP_CTRL_POLL_SHIFT;
+		packed |= control->super << L2CAP_CTRL_SUPER_SHIFT;
+		packed |= L2CAP_CTRL_FRAME_TYPE;
+	} else {
+		packed |= control->sar << L2CAP_CTRL_SAR_SHIFT;
+		packed |= control->txseq << L2CAP_CTRL_TXSEQ_SHIFT;
+	}
+
+	return packed;
+}
+
+static inline void __pack_control(struct l2cap_chan *chan,
+				  struct l2cap_ctrl *control,
+				  struct sk_buff *skb)
+{
+	if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
+		put_unaligned_le32(__pack_extended_control(control),
+				   skb->data + L2CAP_HDR_SIZE);
+	} else {
+		put_unaligned_le16(__pack_enhanced_control(control),
+				   skb->data + L2CAP_HDR_SIZE);
+	}
+}
+
+static inline unsigned int __ertm_hdr_size(struct l2cap_chan *chan)
+{
+	if (test_bit(FLAG_EXT_CTRL, &chan->flags))
+		return L2CAP_EXT_HDR_SIZE;
+	else
+		return L2CAP_ENH_HDR_SIZE;
+}
+
+static struct sk_buff *l2cap_create_sframe_pdu(struct l2cap_chan *chan,
+					       u32 control)
+{
+	struct sk_buff *skb;
+	struct l2cap_hdr *lh;
+	int hlen = __ertm_hdr_size(chan);
+
+	if (chan->fcs == L2CAP_FCS_CRC16)
+		hlen += L2CAP_FCS_SIZE;
+
+	skb = bt_skb_alloc(hlen, GFP_KERNEL);
+
+	if (!skb)
+		return ERR_PTR(-ENOMEM);
+
+	lh = skb_put(skb, L2CAP_HDR_SIZE);
+	lh->len = cpu_to_le16(hlen - L2CAP_HDR_SIZE);
+	lh->cid = cpu_to_le16(chan->dcid);
+
+	if (test_bit(FLAG_EXT_CTRL, &chan->flags))
+		put_unaligned_le32(control, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
+	else
+		put_unaligned_le16(control, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
+
+	if (chan->fcs == L2CAP_FCS_CRC16) {
+		u16 fcs = crc16(0, (u8 *)skb->data, skb->len);
+		put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
+	}
+
+	skb->priority = HCI_PRIO_MAX;
+	return skb;
+}
+
+static void l2cap_send_sframe(struct l2cap_chan *chan,
+			      struct l2cap_ctrl *control)
+{
+	struct sk_buff *skb;
+	u32 control_field;
+
+	BT_DBG("chan %p, control %p", chan, control);
+
+	if (!control->sframe)
+		return;
+
+	if (__chan_is_moving(chan))
+		return;
+
+	if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state) &&
+	    !control->poll)
+		control->final = 1;
+
+	if (control->super == L2CAP_SUPER_RR)
+		clear_bit(CONN_RNR_SENT, &chan->conn_state);
+	else if (control->super == L2CAP_SUPER_RNR)
+		set_bit(CONN_RNR_SENT, &chan->conn_state);
+
+	if (control->super != L2CAP_SUPER_SREJ) {
+		chan->last_acked_seq = control->reqseq;
+		__clear_ack_timer(chan);
+	}
+
+	BT_DBG("reqseq %d, final %d, poll %d, super %d", control->reqseq,
+	       control->final, control->poll, control->super);
+
+	if (test_bit(FLAG_EXT_CTRL, &chan->flags))
+		control_field = __pack_extended_control(control);
+	else
+		control_field = __pack_enhanced_control(control);
+
+	skb = l2cap_create_sframe_pdu(chan, control_field);
+	if (!IS_ERR(skb))
+		l2cap_do_send(chan, skb);
+}
+
+static void l2cap_send_rr_or_rnr(struct l2cap_chan *chan, bool poll)
+{
+	struct l2cap_ctrl control;
+
+	BT_DBG("chan %p, poll %d", chan, poll);
+
+	memset(&control, 0, sizeof(control));
+	control.sframe = 1;
+	control.poll = poll;
+
+	if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
+		control.super = L2CAP_SUPER_RNR;
+	else
+		control.super = L2CAP_SUPER_RR;
+
+	control.reqseq = chan->buffer_seq;
+	l2cap_send_sframe(chan, &control);
+}
+
+static inline int __l2cap_no_conn_pending(struct l2cap_chan *chan)
+{
+	if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
+		return true;
+
+	return !test_bit(CONF_CONNECT_PEND, &chan->conf_state);
+}
+
+static bool __amp_capable(struct l2cap_chan *chan)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct hci_dev *hdev;
+	bool amp_available = false;
+
+	if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
+		return false;
+
+	if (!(conn->remote_fixed_chan & L2CAP_FC_A2MP))
+		return false;
+
+	read_lock(&hci_dev_list_lock);
+	list_for_each_entry(hdev, &hci_dev_list, list) {
+		if (hdev->amp_type != AMP_TYPE_BREDR &&
+		    test_bit(HCI_UP, &hdev->flags)) {
+			amp_available = true;
+			break;
+		}
+	}
+	read_unlock(&hci_dev_list_lock);
+
+	if (chan->chan_policy == BT_CHANNEL_POLICY_AMP_PREFERRED)
+		return amp_available;
+
+	return false;
+}
+
+static bool l2cap_check_efs(struct l2cap_chan *chan)
+{
+	/* Check EFS parameters */
+	return true;
+}
+
+void l2cap_send_conn_req(struct l2cap_chan *chan)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct l2cap_conn_req req;
+
+	req.scid = cpu_to_le16(chan->scid);
+	req.psm  = chan->psm;
+
+	chan->ident = l2cap_get_ident(conn);
+
+	set_bit(CONF_CONNECT_PEND, &chan->conf_state);
+
+	l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_REQ, sizeof(req), &req);
+}
+
+static void l2cap_send_create_chan_req(struct l2cap_chan *chan, u8 amp_id)
+{
+	struct l2cap_create_chan_req req;
+	req.scid = cpu_to_le16(chan->scid);
+	req.psm  = chan->psm;
+	req.amp_id = amp_id;
+
+	chan->ident = l2cap_get_ident(chan->conn);
+
+	l2cap_send_cmd(chan->conn, chan->ident, L2CAP_CREATE_CHAN_REQ,
+		       sizeof(req), &req);
+}
+
+static void l2cap_move_setup(struct l2cap_chan *chan)
+{
+	struct sk_buff *skb;
+
+	BT_DBG("chan %p", chan);
+
+	if (chan->mode != L2CAP_MODE_ERTM)
+		return;
+
+	__clear_retrans_timer(chan);
+	__clear_monitor_timer(chan);
+	__clear_ack_timer(chan);
+
+	chan->retry_count = 0;
+	skb_queue_walk(&chan->tx_q, skb) {
+		if (bt_cb(skb)->l2cap.retries)
+			bt_cb(skb)->l2cap.retries = 1;
+		else
+			break;
+	}
+
+	chan->expected_tx_seq = chan->buffer_seq;
+
+	clear_bit(CONN_REJ_ACT, &chan->conn_state);
+	clear_bit(CONN_SREJ_ACT, &chan->conn_state);
+	l2cap_seq_list_clear(&chan->retrans_list);
+	l2cap_seq_list_clear(&chan->srej_list);
+	skb_queue_purge(&chan->srej_q);
+
+	chan->tx_state = L2CAP_TX_STATE_XMIT;
+	chan->rx_state = L2CAP_RX_STATE_MOVE;
+
+	set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
+}
+
+static void l2cap_move_done(struct l2cap_chan *chan)
+{
+	u8 move_role = chan->move_role;
+	BT_DBG("chan %p", chan);
+
+	chan->move_state = L2CAP_MOVE_STABLE;
+	chan->move_role = L2CAP_MOVE_ROLE_NONE;
+
+	if (chan->mode != L2CAP_MODE_ERTM)
+		return;
+
+	switch (move_role) {
+	case L2CAP_MOVE_ROLE_INITIATOR:
+		l2cap_tx(chan, NULL, NULL, L2CAP_EV_EXPLICIT_POLL);
+		chan->rx_state = L2CAP_RX_STATE_WAIT_F;
+		break;
+	case L2CAP_MOVE_ROLE_RESPONDER:
+		chan->rx_state = L2CAP_RX_STATE_WAIT_P;
+		break;
+	}
+}
+
+static void l2cap_chan_ready(struct l2cap_chan *chan)
+{
+	/* The channel may have already been flagged as connected in
+	 * case of receiving data before the L2CAP info req/rsp
+	 * procedure is complete.
+	 */
+	if (chan->state == BT_CONNECTED)
+		return;
+
+	/* This clears all conf flags, including CONF_NOT_COMPLETE */
+	chan->conf_state = 0;
+	__clear_chan_timer(chan);
+
+	switch (chan->mode) {
+	case L2CAP_MODE_LE_FLOWCTL:
+	case L2CAP_MODE_EXT_FLOWCTL:
+		if (!chan->tx_credits)
+			chan->ops->suspend(chan);
+		break;
+	}
+
+	chan->state = BT_CONNECTED;
+
+	chan->ops->ready(chan);
+}
+
+static void l2cap_le_connect(struct l2cap_chan *chan)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct l2cap_le_conn_req req;
+
+	if (test_and_set_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags))
+		return;
+
+	if (!chan->imtu)
+		chan->imtu = chan->conn->mtu;
+
+	l2cap_le_flowctl_init(chan, 0);
+
+	memset(&req, 0, sizeof(req));
+	req.psm     = chan->psm;
+	req.scid    = cpu_to_le16(chan->scid);
+	req.mtu     = cpu_to_le16(chan->imtu);
+	req.mps     = cpu_to_le16(chan->mps);
+	req.credits = cpu_to_le16(chan->rx_credits);
+
+	chan->ident = l2cap_get_ident(conn);
+
+	l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_REQ,
+		       sizeof(req), &req);
+}
+
+struct l2cap_ecred_conn_data {
+	struct {
+		struct l2cap_ecred_conn_req req;
+		__le16 scid[5];
+	} __packed pdu;
+	struct l2cap_chan *chan;
+	struct pid *pid;
+	int count;
+};
+
+static void l2cap_ecred_defer_connect(struct l2cap_chan *chan, void *data)
+{
+	struct l2cap_ecred_conn_data *conn = data;
+	struct pid *pid;
+
+	if (chan == conn->chan)
+		return;
+
+	if (!test_and_clear_bit(FLAG_DEFER_SETUP, &chan->flags))
+		return;
+
+	pid = chan->ops->get_peer_pid(chan);
+
+	/* Only add deferred channels with the same PID/PSM */
+	if (conn->pid != pid || chan->psm != conn->chan->psm || chan->ident ||
+	    chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT)
+		return;
+
+	if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
+		return;
+
+	l2cap_ecred_init(chan, 0);
+
+	/* Set the same ident so we can match on the rsp */
+	chan->ident = conn->chan->ident;
+
+	/* Include all channels deferred */
+	conn->pdu.scid[conn->count] = cpu_to_le16(chan->scid);
+
+	conn->count++;
+}
+
+static void l2cap_ecred_connect(struct l2cap_chan *chan)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct l2cap_ecred_conn_data data;
+
+	if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
+		return;
+
+	if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
+		return;
+
+	l2cap_ecred_init(chan, 0);
+
+	memset(&data, 0, sizeof(data));
+	data.pdu.req.psm     = chan->psm;
+	data.pdu.req.mtu     = cpu_to_le16(chan->imtu);
+	data.pdu.req.mps     = cpu_to_le16(chan->mps);
+	data.pdu.req.credits = cpu_to_le16(chan->rx_credits);
+	data.pdu.scid[0]     = cpu_to_le16(chan->scid);
+
+	chan->ident = l2cap_get_ident(conn);
+
+	data.count = 1;
+	data.chan = chan;
+	data.pid = chan->ops->get_peer_pid(chan);
+
+	__l2cap_chan_list(conn, l2cap_ecred_defer_connect, &data);
+
+	l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_CONN_REQ,
+		       sizeof(data.pdu.req) + data.count * sizeof(__le16),
+		       &data.pdu);
+}
+
+static void l2cap_le_start(struct l2cap_chan *chan)
+{
+	struct l2cap_conn *conn = chan->conn;
+
+	if (!smp_conn_security(conn->hcon, chan->sec_level))
+		return;
+
+	if (!chan->psm) {
+		l2cap_chan_ready(chan);
+		return;
+	}
+
+	if (chan->state == BT_CONNECT) {
+		if (chan->mode == L2CAP_MODE_EXT_FLOWCTL)
+			l2cap_ecred_connect(chan);
+		else
+			l2cap_le_connect(chan);
+	}
+}
+
+static void l2cap_start_connection(struct l2cap_chan *chan)
+{
+	if (__amp_capable(chan)) {
+		BT_DBG("chan %p AMP capable: discover AMPs", chan);
+		a2mp_discover_amp(chan);
+	} else if (chan->conn->hcon->type == LE_LINK) {
+		l2cap_le_start(chan);
+	} else {
+		l2cap_send_conn_req(chan);
+	}
+}
+
+static void l2cap_request_info(struct l2cap_conn *conn)
+{
+	struct l2cap_info_req req;
+
+	if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
+		return;
+
+	req.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
+
+	conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
+	conn->info_ident = l2cap_get_ident(conn);
+
+	schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
+
+	l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
+		       sizeof(req), &req);
+}
+
+static bool l2cap_check_enc_key_size(struct hci_conn *hcon)
+{
+	/* The minimum encryption key size needs to be enforced by the
+	 * host stack before establishing any L2CAP connections. The
+	 * specification in theory allows a minimum of 1, but to align
+	 * BR/EDR and LE transports, a minimum of 7 is chosen.
+	 *
+	 * This check might also be called for unencrypted connections
+	 * that have no key size requirements. Ensure that the link is
+	 * actually encrypted before enforcing a key size.
+	 */
+	int min_key_size = hcon->hdev->min_enc_key_size;
+
+	/* On FIPS security level, key size must be 16 bytes */
+	if (hcon->sec_level == BT_SECURITY_FIPS)
+		min_key_size = 16;
+
+	return (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags) ||
+		hcon->enc_key_size >= min_key_size);
+}
+
+static void l2cap_do_start(struct l2cap_chan *chan)
+{
+	struct l2cap_conn *conn = chan->conn;
+
+	if (conn->hcon->type == LE_LINK) {
+		l2cap_le_start(chan);
+		return;
+	}
+
+	if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)) {
+		l2cap_request_info(conn);
+		return;
+	}
+
+	if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE))
+		return;
+
+	if (!l2cap_chan_check_security(chan, true) ||
+	    !__l2cap_no_conn_pending(chan))
+		return;
+
+	if (l2cap_check_enc_key_size(conn->hcon))
+		l2cap_start_connection(chan);
+	else
+		__set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
+}
+
+static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
+{
+	u32 local_feat_mask = l2cap_feat_mask;
+	if (!disable_ertm)
+		local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING;
+
+	switch (mode) {
+	case L2CAP_MODE_ERTM:
+		return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask;
+	case L2CAP_MODE_STREAMING:
+		return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask;
+	default:
+		return 0x00;
+	}
+}
+
+static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct l2cap_disconn_req req;
+
+	if (!conn)
+		return;
+
+	if (chan->mode == L2CAP_MODE_ERTM && chan->state == BT_CONNECTED) {
+		__clear_retrans_timer(chan);
+		__clear_monitor_timer(chan);
+		__clear_ack_timer(chan);
+	}
+
+	if (chan->scid == L2CAP_CID_A2MP) {
+		l2cap_state_change(chan, BT_DISCONN);
+		return;
+	}
+
+	req.dcid = cpu_to_le16(chan->dcid);
+	req.scid = cpu_to_le16(chan->scid);
+	l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_DISCONN_REQ,
+		       sizeof(req), &req);
+
+	l2cap_state_change_and_error(chan, BT_DISCONN, err);
+}
+
+/* ---- L2CAP connections ---- */
+static void l2cap_conn_start(struct l2cap_conn *conn)
+{
+	struct l2cap_chan *chan, *tmp;
+
+	BT_DBG("conn %p", conn);
+
+	mutex_lock(&conn->chan_lock);
+
+	list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
+		l2cap_chan_lock(chan);
+
+		if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
+			l2cap_chan_ready(chan);
+			l2cap_chan_unlock(chan);
+			continue;
+		}
+
+		if (chan->state == BT_CONNECT) {
+			if (!l2cap_chan_check_security(chan, true) ||
+			    !__l2cap_no_conn_pending(chan)) {
+				l2cap_chan_unlock(chan);
+				continue;
+			}
+
+			if (!l2cap_mode_supported(chan->mode, conn->feat_mask)
+			    && test_bit(CONF_STATE2_DEVICE,
+					&chan->conf_state)) {
+				l2cap_chan_close(chan, ECONNRESET);
+				l2cap_chan_unlock(chan);
+				continue;
+			}
+
+			if (l2cap_check_enc_key_size(conn->hcon))
+				l2cap_start_connection(chan);
+			else
+				l2cap_chan_close(chan, ECONNREFUSED);
+
+		} else if (chan->state == BT_CONNECT2) {
+			struct l2cap_conn_rsp rsp;
+			char buf[128];
+			rsp.scid = cpu_to_le16(chan->dcid);
+			rsp.dcid = cpu_to_le16(chan->scid);
+
+			if (l2cap_chan_check_security(chan, false)) {
+				if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
+					rsp.result = cpu_to_le16(L2CAP_CR_PEND);
+					rsp.status = cpu_to_le16(L2CAP_CS_AUTHOR_PEND);
+					chan->ops->defer(chan);
+
+				} else {
+					l2cap_state_change(chan, BT_CONFIG);
+					rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
+					rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
+				}
+			} else {
+				rsp.result = cpu_to_le16(L2CAP_CR_PEND);
+				rsp.status = cpu_to_le16(L2CAP_CS_AUTHEN_PEND);
+			}
+
+			l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
+				       sizeof(rsp), &rsp);
+
+			if (test_bit(CONF_REQ_SENT, &chan->conf_state) ||
+			    rsp.result != L2CAP_CR_SUCCESS) {
+				l2cap_chan_unlock(chan);
+				continue;
+			}
+
+			set_bit(CONF_REQ_SENT, &chan->conf_state);
+			l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
+				       l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
+			chan->num_conf_req++;
+		}
+
+		l2cap_chan_unlock(chan);
+	}
+
+	mutex_unlock(&conn->chan_lock);
+}
+
+static void l2cap_le_conn_ready(struct l2cap_conn *conn)
+{
+	struct hci_conn *hcon = conn->hcon;
+	struct hci_dev *hdev = hcon->hdev;
+
+	BT_DBG("%s conn %p", hdev->name, conn);
+
+	/* For outgoing pairing which doesn't necessarily have an
+	 * associated socket (e.g. mgmt_pair_device).
+	 */
+	if (hcon->out)
+		smp_conn_security(hcon, hcon->pending_sec_level);
+
+	/* For LE peripheral connections, make sure the connection interval
+	 * is in the range of the minimum and maximum interval that has
+	 * been configured for this connection. If not, then trigger
+	 * the connection update procedure.
+	 */
+	if (hcon->role == HCI_ROLE_SLAVE &&
+	    (hcon->le_conn_interval < hcon->le_conn_min_interval ||
+	     hcon->le_conn_interval > hcon->le_conn_max_interval)) {
+		struct l2cap_conn_param_update_req req;
+
+		req.min = cpu_to_le16(hcon->le_conn_min_interval);
+		req.max = cpu_to_le16(hcon->le_conn_max_interval);
+		req.latency = cpu_to_le16(hcon->le_conn_latency);
+		req.to_multiplier = cpu_to_le16(hcon->le_supv_timeout);
+
+		l2cap_send_cmd(conn, l2cap_get_ident(conn),
+			       L2CAP_CONN_PARAM_UPDATE_REQ, sizeof(req), &req);
+	}
+}
+
+static void l2cap_conn_ready(struct l2cap_conn *conn)
+{
+	struct l2cap_chan *chan;
+	struct hci_conn *hcon = conn->hcon;
+
+	BT_DBG("conn %p", conn);
+
+	if (hcon->type == ACL_LINK)
+		l2cap_request_info(conn);
+
+	mutex_lock(&conn->chan_lock);
+
+	list_for_each_entry(chan, &conn->chan_l, list) {
+
+		l2cap_chan_lock(chan);
+
+		if (chan->scid == L2CAP_CID_A2MP) {
+			l2cap_chan_unlock(chan);
+			continue;
+		}
+
+		if (hcon->type == LE_LINK) {
+			l2cap_le_start(chan);
+		} else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
+			if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
+				l2cap_chan_ready(chan);
+		} else if (chan->state == BT_CONNECT) {
+			l2cap_do_start(chan);
+		}
+
+		l2cap_chan_unlock(chan);
+	}
+
+	mutex_unlock(&conn->chan_lock);
+
+	if (hcon->type == LE_LINK)
+		l2cap_le_conn_ready(conn);
+
+	queue_work(hcon->hdev->workqueue, &conn->pending_rx_work);
+}
+
+/* Notify sockets that we cannot guaranty reliability anymore */
+static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err)
+{
+	struct l2cap_chan *chan;
+
+	BT_DBG("conn %p", conn);
+
+	mutex_lock(&conn->chan_lock);
+
+	list_for_each_entry(chan, &conn->chan_l, list) {
+		if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
+			l2cap_chan_set_err(chan, err);
+	}
+
+	mutex_unlock(&conn->chan_lock);
+}
+
+static void l2cap_info_timeout(struct work_struct *work)
+{
+	struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
+					       info_timer.work);
+
+	conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
+	conn->info_ident = 0;
+
+	l2cap_conn_start(conn);
+}
+
+/*
+ * l2cap_user
+ * External modules can register l2cap_user objects on l2cap_conn. The ->probe
+ * callback is called during registration. The ->remove callback is called
+ * during unregistration.
+ * An l2cap_user object can either be explicitly unregistered or when the
+ * underlying l2cap_conn object is deleted. This guarantees that l2cap->hcon,
+ * l2cap->hchan, .. are valid as long as the remove callback hasn't been called.
+ * External modules must own a reference to the l2cap_conn object if they intend
+ * to call l2cap_unregister_user(). The l2cap_conn object might get destroyed at
+ * any time if they don't.
+ */
+
+int l2cap_register_user(struct l2cap_conn *conn, struct l2cap_user *user)
+{
+	struct hci_dev *hdev = conn->hcon->hdev;
+	int ret;
+
+	/* We need to check whether l2cap_conn is registered. If it is not, we
+	 * must not register the l2cap_user. l2cap_conn_del() is unregisters
+	 * l2cap_conn objects, but doesn't provide its own locking. Instead, it
+	 * relies on the parent hci_conn object to be locked. This itself relies
+	 * on the hci_dev object to be locked. So we must lock the hci device
+	 * here, too. */
+
+	hci_dev_lock(hdev);
+
+	if (!list_empty(&user->list)) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	/* conn->hchan is NULL after l2cap_conn_del() was called */
+	if (!conn->hchan) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	ret = user->probe(conn, user);
+	if (ret)
+		goto out_unlock;
+
+	list_add(&user->list, &conn->users);
+	ret = 0;
+
+out_unlock:
+	hci_dev_unlock(hdev);
+	return ret;
+}
+EXPORT_SYMBOL(l2cap_register_user);
+
+void l2cap_unregister_user(struct l2cap_conn *conn, struct l2cap_user *user)
+{
+	struct hci_dev *hdev = conn->hcon->hdev;
+
+	hci_dev_lock(hdev);
+
+	if (list_empty(&user->list))
+		goto out_unlock;
+
+	list_del_init(&user->list);
+	user->remove(conn, user);
+
+out_unlock:
+	hci_dev_unlock(hdev);
+}
+EXPORT_SYMBOL(l2cap_unregister_user);
+
+static void l2cap_unregister_all_users(struct l2cap_conn *conn)
+{
+	struct l2cap_user *user;
+
+	while (!list_empty(&conn->users)) {
+		user = list_first_entry(&conn->users, struct l2cap_user, list);
+		list_del_init(&user->list);
+		user->remove(conn, user);
+	}
+}
+
+static void l2cap_conn_del(struct hci_conn *hcon, int err)
+{
+	struct l2cap_conn *conn = hcon->l2cap_data;
+	struct l2cap_chan *chan, *l;
+
+	if (!conn)
+		return;
+
+	BT_DBG("hcon %p conn %p, err %d", hcon, conn, err);
+
+	kfree_skb(conn->rx_skb);
+
+	skb_queue_purge(&conn->pending_rx);
+
+	/* We can not call flush_work(&conn->pending_rx_work) here since we
+	 * might block if we are running on a worker from the same workqueue
+	 * pending_rx_work is waiting on.
+	 */
+	if (work_pending(&conn->pending_rx_work))
+		cancel_work_sync(&conn->pending_rx_work);
+
+	if (work_pending(&conn->id_addr_update_work))
+		cancel_work_sync(&conn->id_addr_update_work);
+
+	l2cap_unregister_all_users(conn);
+
+	/* Force the connection to be immediately dropped */
+	hcon->disc_timeout = 0;
+
+	mutex_lock(&conn->chan_lock);
+
+	/* Kill channels */
+	list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
+		l2cap_chan_hold(chan);
+		l2cap_chan_lock(chan);
+
+		l2cap_chan_del(chan, err);
+
+		chan->ops->close(chan);
+
+		l2cap_chan_unlock(chan);
+		l2cap_chan_put(chan);
+	}
+
+	mutex_unlock(&conn->chan_lock);
+
+	hci_chan_del(conn->hchan);
+
+	if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
+		cancel_delayed_work_sync(&conn->info_timer);
+
+	hcon->l2cap_data = NULL;
+	conn->hchan = NULL;
+	l2cap_conn_put(conn);
+}
+
+static void l2cap_conn_free(struct kref *ref)
+{
+	struct l2cap_conn *conn = container_of(ref, struct l2cap_conn, ref);
+
+	hci_conn_put(conn->hcon);
+	kfree(conn);
+}
+
+struct l2cap_conn *l2cap_conn_get(struct l2cap_conn *conn)
+{
+	kref_get(&conn->ref);
+	return conn;
+}
+EXPORT_SYMBOL(l2cap_conn_get);
+
+void l2cap_conn_put(struct l2cap_conn *conn)
+{
+	kref_put(&conn->ref, l2cap_conn_free);
+}
+EXPORT_SYMBOL(l2cap_conn_put);
+
+/* ---- Socket interface ---- */
+
+/* Find socket with psm and source / destination bdaddr.
+ * Returns closest match.
+ */
+static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
+						   bdaddr_t *src,
+						   bdaddr_t *dst,
+						   u8 link_type)
+{
+	struct l2cap_chan *c, *tmp, *c1 = NULL;
+
+	read_lock(&chan_list_lock);
+
+	list_for_each_entry_safe(c, tmp, &chan_list, global_l) {
+		if (state && c->state != state)
+			continue;
+
+		if (link_type == ACL_LINK && c->src_type != BDADDR_BREDR)
+			continue;
+
+		if (link_type == LE_LINK && c->src_type == BDADDR_BREDR)
+			continue;
+
+		if (c->chan_type != L2CAP_CHAN_FIXED && c->psm == psm) {
+			int src_match, dst_match;
+			int src_any, dst_any;
+
+			/* Exact match. */
+			src_match = !bacmp(&c->src, src);
+			dst_match = !bacmp(&c->dst, dst);
+			if (src_match && dst_match) {
+				if (!l2cap_chan_hold_unless_zero(c))
+					continue;
+
+				read_unlock(&chan_list_lock);
+				return c;
+			}
+
+			/* Closest match */
+			src_any = !bacmp(&c->src, BDADDR_ANY);
+			dst_any = !bacmp(&c->dst, BDADDR_ANY);
+			if ((src_match && dst_any) || (src_any && dst_match) ||
+			    (src_any && dst_any))
+				c1 = c;
+		}
+	}
+
+	if (c1)
+		c1 = l2cap_chan_hold_unless_zero(c1);
+
+	read_unlock(&chan_list_lock);
+
+	return c1;
+}
+
+static void l2cap_monitor_timeout(struct work_struct *work)
+{
+	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
+					       monitor_timer.work);
+
+	BT_DBG("chan %p", chan);
+
+	l2cap_chan_lock(chan);
+
+	if (!chan->conn) {
+		l2cap_chan_unlock(chan);
+		l2cap_chan_put(chan);
+		return;
+	}
+
+	l2cap_tx(chan, NULL, NULL, L2CAP_EV_MONITOR_TO);
+
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+}
+
+static void l2cap_retrans_timeout(struct work_struct *work)
+{
+	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
+					       retrans_timer.work);
+
+	BT_DBG("chan %p", chan);
+
+	l2cap_chan_lock(chan);
+
+	if (!chan->conn) {
+		l2cap_chan_unlock(chan);
+		l2cap_chan_put(chan);
+		return;
+	}
+
+	l2cap_tx(chan, NULL, NULL, L2CAP_EV_RETRANS_TO);
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+}
+
+static void l2cap_streaming_send(struct l2cap_chan *chan,
+				 struct sk_buff_head *skbs)
+{
+	struct sk_buff *skb;
+	struct l2cap_ctrl *control;
+
+	BT_DBG("chan %p, skbs %p", chan, skbs);
+
+	if (__chan_is_moving(chan))
+		return;
+
+	skb_queue_splice_tail_init(skbs, &chan->tx_q);
+
+	while (!skb_queue_empty(&chan->tx_q)) {
+
+		skb = skb_dequeue(&chan->tx_q);
+
+		bt_cb(skb)->l2cap.retries = 1;
+		control = &bt_cb(skb)->l2cap;
+
+		control->reqseq = 0;
+		control->txseq = chan->next_tx_seq;
+
+		__pack_control(chan, control, skb);
+
+		if (chan->fcs == L2CAP_FCS_CRC16) {
+			u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
+			put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
+		}
+
+		l2cap_do_send(chan, skb);
+
+		BT_DBG("Sent txseq %u", control->txseq);
+
+		chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
+		chan->frames_sent++;
+	}
+}
+
+static int l2cap_ertm_send(struct l2cap_chan *chan)
+{
+	struct sk_buff *skb, *tx_skb;
+	struct l2cap_ctrl *control;
+	int sent = 0;
+
+	BT_DBG("chan %p", chan);
+
+	if (chan->state != BT_CONNECTED)
+		return -ENOTCONN;
+
+	if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
+		return 0;
+
+	if (__chan_is_moving(chan))
+		return 0;
+
+	while (chan->tx_send_head &&
+	       chan->unacked_frames < chan->remote_tx_win &&
+	       chan->tx_state == L2CAP_TX_STATE_XMIT) {
+
+		skb = chan->tx_send_head;
+
+		bt_cb(skb)->l2cap.retries = 1;
+		control = &bt_cb(skb)->l2cap;
+
+		if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
+			control->final = 1;
+
+		control->reqseq = chan->buffer_seq;
+		chan->last_acked_seq = chan->buffer_seq;
+		control->txseq = chan->next_tx_seq;
+
+		__pack_control(chan, control, skb);
+
+		if (chan->fcs == L2CAP_FCS_CRC16) {
+			u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
+			put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
+		}
+
+		/* Clone after data has been modified. Data is assumed to be
+		   read-only (for locking purposes) on cloned sk_buffs.
+		 */
+		tx_skb = skb_clone(skb, GFP_KERNEL);
+
+		if (!tx_skb)
+			break;
+
+		__set_retrans_timer(chan);
+
+		chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
+		chan->unacked_frames++;
+		chan->frames_sent++;
+		sent++;
+
+		if (skb_queue_is_last(&chan->tx_q, skb))
+			chan->tx_send_head = NULL;
+		else
+			chan->tx_send_head = skb_queue_next(&chan->tx_q, skb);
+
+		l2cap_do_send(chan, tx_skb);
+		BT_DBG("Sent txseq %u", control->txseq);
+	}
+
+	BT_DBG("Sent %d, %u unacked, %u in ERTM queue", sent,
+	       chan->unacked_frames, skb_queue_len(&chan->tx_q));
+
+	return sent;
+}
+
+static void l2cap_ertm_resend(struct l2cap_chan *chan)
+{
+	struct l2cap_ctrl control;
+	struct sk_buff *skb;
+	struct sk_buff *tx_skb;
+	u16 seq;
+
+	BT_DBG("chan %p", chan);
+
+	if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
+		return;
+
+	if (__chan_is_moving(chan))
+		return;
+
+	while (chan->retrans_list.head != L2CAP_SEQ_LIST_CLEAR) {
+		seq = l2cap_seq_list_pop(&chan->retrans_list);
+
+		skb = l2cap_ertm_seq_in_queue(&chan->tx_q, seq);
+		if (!skb) {
+			BT_DBG("Error: Can't retransmit seq %d, frame missing",
+			       seq);
+			continue;
+		}
+
+		bt_cb(skb)->l2cap.retries++;
+		control = bt_cb(skb)->l2cap;
+
+		if (chan->max_tx != 0 &&
+		    bt_cb(skb)->l2cap.retries > chan->max_tx) {
+			BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
+			l2cap_send_disconn_req(chan, ECONNRESET);
+			l2cap_seq_list_clear(&chan->retrans_list);
+			break;
+		}
+
+		control.reqseq = chan->buffer_seq;
+		if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
+			control.final = 1;
+		else
+			control.final = 0;
+
+		if (skb_cloned(skb)) {
+			/* Cloned sk_buffs are read-only, so we need a
+			 * writeable copy
+			 */
+			tx_skb = skb_copy(skb, GFP_KERNEL);
+		} else {
+			tx_skb = skb_clone(skb, GFP_KERNEL);
+		}
+
+		if (!tx_skb) {
+			l2cap_seq_list_clear(&chan->retrans_list);
+			break;
+		}
+
+		/* Update skb contents */
+		if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
+			put_unaligned_le32(__pack_extended_control(&control),
+					   tx_skb->data + L2CAP_HDR_SIZE);
+		} else {
+			put_unaligned_le16(__pack_enhanced_control(&control),
+					   tx_skb->data + L2CAP_HDR_SIZE);
+		}
+
+		/* Update FCS */
+		if (chan->fcs == L2CAP_FCS_CRC16) {
+			u16 fcs = crc16(0, (u8 *) tx_skb->data,
+					tx_skb->len - L2CAP_FCS_SIZE);
+			put_unaligned_le16(fcs, skb_tail_pointer(tx_skb) -
+						L2CAP_FCS_SIZE);
+		}
+
+		l2cap_do_send(chan, tx_skb);
+
+		BT_DBG("Resent txseq %d", control.txseq);
+
+		chan->last_acked_seq = chan->buffer_seq;
+	}
+}
+
+static void l2cap_retransmit(struct l2cap_chan *chan,
+			     struct l2cap_ctrl *control)
+{
+	BT_DBG("chan %p, control %p", chan, control);
+
+	l2cap_seq_list_append(&chan->retrans_list, control->reqseq);
+	l2cap_ertm_resend(chan);
+}
+
+static void l2cap_retransmit_all(struct l2cap_chan *chan,
+				 struct l2cap_ctrl *control)
+{
+	struct sk_buff *skb;
+
+	BT_DBG("chan %p, control %p", chan, control);
+
+	if (control->poll)
+		set_bit(CONN_SEND_FBIT, &chan->conn_state);
+
+	l2cap_seq_list_clear(&chan->retrans_list);
+
+	if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
+		return;
+
+	if (chan->unacked_frames) {
+		skb_queue_walk(&chan->tx_q, skb) {
+			if (bt_cb(skb)->l2cap.txseq == control->reqseq ||
+			    skb == chan->tx_send_head)
+				break;
+		}
+
+		skb_queue_walk_from(&chan->tx_q, skb) {
+			if (skb == chan->tx_send_head)
+				break;
+
+			l2cap_seq_list_append(&chan->retrans_list,
+					      bt_cb(skb)->l2cap.txseq);
+		}
+
+		l2cap_ertm_resend(chan);
+	}
+}
+
+static void l2cap_send_ack(struct l2cap_chan *chan)
+{
+	struct l2cap_ctrl control;
+	u16 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
+					 chan->last_acked_seq);
+	int threshold;
+
+	BT_DBG("chan %p last_acked_seq %d buffer_seq %d",
+	       chan, chan->last_acked_seq, chan->buffer_seq);
+
+	memset(&control, 0, sizeof(control));
+	control.sframe = 1;
+
+	if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
+	    chan->rx_state == L2CAP_RX_STATE_RECV) {
+		__clear_ack_timer(chan);
+		control.super = L2CAP_SUPER_RNR;
+		control.reqseq = chan->buffer_seq;
+		l2cap_send_sframe(chan, &control);
+	} else {
+		if (!test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) {
+			l2cap_ertm_send(chan);
+			/* If any i-frames were sent, they included an ack */
+			if (chan->buffer_seq == chan->last_acked_seq)
+				frames_to_ack = 0;
+		}
+
+		/* Ack now if the window is 3/4ths full.
+		 * Calculate without mul or div
+		 */
+		threshold = chan->ack_win;
+		threshold += threshold << 1;
+		threshold >>= 2;
+
+		BT_DBG("frames_to_ack %u, threshold %d", frames_to_ack,
+		       threshold);
+
+		if (frames_to_ack >= threshold) {
+			__clear_ack_timer(chan);
+			control.super = L2CAP_SUPER_RR;
+			control.reqseq = chan->buffer_seq;
+			l2cap_send_sframe(chan, &control);
+			frames_to_ack = 0;
+		}
+
+		if (frames_to_ack)
+			__set_ack_timer(chan);
+	}
+}
+
+static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
+					 struct msghdr *msg, int len,
+					 int count, struct sk_buff *skb)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct sk_buff **frag;
+	int sent = 0;
+
+	if (!copy_from_iter_full(skb_put(skb, count), count, &msg->msg_iter))
+		return -EFAULT;
+
+	sent += count;
+	len  -= count;
+
+	/* Continuation fragments (no L2CAP header) */
+	frag = &skb_shinfo(skb)->frag_list;
+	while (len) {
+		struct sk_buff *tmp;
+
+		count = min_t(unsigned int, conn->mtu, len);
+
+		tmp = chan->ops->alloc_skb(chan, 0, count,
+					   msg->msg_flags & MSG_DONTWAIT);
+		if (IS_ERR(tmp))
+			return PTR_ERR(tmp);
+
+		*frag = tmp;
+
+		if (!copy_from_iter_full(skb_put(*frag, count), count,
+				   &msg->msg_iter))
+			return -EFAULT;
+
+		sent += count;
+		len  -= count;
+
+		skb->len += (*frag)->len;
+		skb->data_len += (*frag)->len;
+
+		frag = &(*frag)->next;
+	}
+
+	return sent;
+}
+
+static struct sk_buff *l2cap_create_connless_pdu(struct l2cap_chan *chan,
+						 struct msghdr *msg, size_t len)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct sk_buff *skb;
+	int err, count, hlen = L2CAP_HDR_SIZE + L2CAP_PSMLEN_SIZE;
+	struct l2cap_hdr *lh;
+
+	BT_DBG("chan %p psm 0x%2.2x len %zu", chan,
+	       __le16_to_cpu(chan->psm), len);
+
+	count = min_t(unsigned int, (conn->mtu - hlen), len);
+
+	skb = chan->ops->alloc_skb(chan, hlen, count,
+				   msg->msg_flags & MSG_DONTWAIT);
+	if (IS_ERR(skb))
+		return skb;
+
+	/* Create L2CAP header */
+	lh = skb_put(skb, L2CAP_HDR_SIZE);
+	lh->cid = cpu_to_le16(chan->dcid);
+	lh->len = cpu_to_le16(len + L2CAP_PSMLEN_SIZE);
+	put_unaligned(chan->psm, (__le16 *) skb_put(skb, L2CAP_PSMLEN_SIZE));
+
+	err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
+	if (unlikely(err < 0)) {
+		kfree_skb(skb);
+		return ERR_PTR(err);
+	}
+	return skb;
+}
+
+static struct sk_buff *l2cap_create_basic_pdu(struct l2cap_chan *chan,
+					      struct msghdr *msg, size_t len)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct sk_buff *skb;
+	int err, count;
+	struct l2cap_hdr *lh;
+
+	BT_DBG("chan %p len %zu", chan, len);
+
+	count = min_t(unsigned int, (conn->mtu - L2CAP_HDR_SIZE), len);
+
+	skb = chan->ops->alloc_skb(chan, L2CAP_HDR_SIZE, count,
+				   msg->msg_flags & MSG_DONTWAIT);
+	if (IS_ERR(skb))
+		return skb;
+
+	/* Create L2CAP header */
+	lh = skb_put(skb, L2CAP_HDR_SIZE);
+	lh->cid = cpu_to_le16(chan->dcid);
+	lh->len = cpu_to_le16(len);
+
+	err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
+	if (unlikely(err < 0)) {
+		kfree_skb(skb);
+		return ERR_PTR(err);
+	}
+	return skb;
+}
+
+static struct sk_buff *l2cap_create_iframe_pdu(struct l2cap_chan *chan,
+					       struct msghdr *msg, size_t len,
+					       u16 sdulen)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct sk_buff *skb;
+	int err, count, hlen;
+	struct l2cap_hdr *lh;
+
+	BT_DBG("chan %p len %zu", chan, len);
+
+	if (!conn)
+		return ERR_PTR(-ENOTCONN);
+
+	hlen = __ertm_hdr_size(chan);
+
+	if (sdulen)
+		hlen += L2CAP_SDULEN_SIZE;
+
+	if (chan->fcs == L2CAP_FCS_CRC16)
+		hlen += L2CAP_FCS_SIZE;
+
+	count = min_t(unsigned int, (conn->mtu - hlen), len);
+
+	skb = chan->ops->alloc_skb(chan, hlen, count,
+				   msg->msg_flags & MSG_DONTWAIT);
+	if (IS_ERR(skb))
+		return skb;
+
+	/* Create L2CAP header */
+	lh = skb_put(skb, L2CAP_HDR_SIZE);
+	lh->cid = cpu_to_le16(chan->dcid);
+	lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
+
+	/* Control header is populated later */
+	if (test_bit(FLAG_EXT_CTRL, &chan->flags))
+		put_unaligned_le32(0, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
+	else
+		put_unaligned_le16(0, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
+
+	if (sdulen)
+		put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
+
+	err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
+	if (unlikely(err < 0)) {
+		kfree_skb(skb);
+		return ERR_PTR(err);
+	}
+
+	bt_cb(skb)->l2cap.fcs = chan->fcs;
+	bt_cb(skb)->l2cap.retries = 0;
+	return skb;
+}
+
+static int l2cap_segment_sdu(struct l2cap_chan *chan,
+			     struct sk_buff_head *seg_queue,
+			     struct msghdr *msg, size_t len)
+{
+	struct sk_buff *skb;
+	u16 sdu_len;
+	size_t pdu_len;
+	u8 sar;
+
+	BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
+
+	/* It is critical that ERTM PDUs fit in a single HCI fragment,
+	 * so fragmented skbs are not used.  The HCI layer's handling
+	 * of fragmented skbs is not compatible with ERTM's queueing.
+	 */
+
+	/* PDU size is derived from the HCI MTU */
+	pdu_len = chan->conn->mtu;
+
+	/* Constrain PDU size for BR/EDR connections */
+	if (!chan->hs_hcon)
+		pdu_len = min_t(size_t, pdu_len, L2CAP_BREDR_MAX_PAYLOAD);
+
+	/* Adjust for largest possible L2CAP overhead. */
+	if (chan->fcs)
+		pdu_len -= L2CAP_FCS_SIZE;
+
+	pdu_len -= __ertm_hdr_size(chan);
+
+	/* Remote device may have requested smaller PDUs */
+	pdu_len = min_t(size_t, pdu_len, chan->remote_mps);
+
+	if (len <= pdu_len) {
+		sar = L2CAP_SAR_UNSEGMENTED;
+		sdu_len = 0;
+		pdu_len = len;
+	} else {
+		sar = L2CAP_SAR_START;
+		sdu_len = len;
+	}
+
+	while (len > 0) {
+		skb = l2cap_create_iframe_pdu(chan, msg, pdu_len, sdu_len);
+
+		if (IS_ERR(skb)) {
+			__skb_queue_purge(seg_queue);
+			return PTR_ERR(skb);
+		}
+
+		bt_cb(skb)->l2cap.sar = sar;
+		__skb_queue_tail(seg_queue, skb);
+
+		len -= pdu_len;
+		if (sdu_len)
+			sdu_len = 0;
+
+		if (len <= pdu_len) {
+			sar = L2CAP_SAR_END;
+			pdu_len = len;
+		} else {
+			sar = L2CAP_SAR_CONTINUE;
+		}
+	}
+
+	return 0;
+}
+
+static struct sk_buff *l2cap_create_le_flowctl_pdu(struct l2cap_chan *chan,
+						   struct msghdr *msg,
+						   size_t len, u16 sdulen)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct sk_buff *skb;
+	int err, count, hlen;
+	struct l2cap_hdr *lh;
+
+	BT_DBG("chan %p len %zu", chan, len);
+
+	if (!conn)
+		return ERR_PTR(-ENOTCONN);
+
+	hlen = L2CAP_HDR_SIZE;
+
+	if (sdulen)
+		hlen += L2CAP_SDULEN_SIZE;
+
+	count = min_t(unsigned int, (conn->mtu - hlen), len);
+
+	skb = chan->ops->alloc_skb(chan, hlen, count,
+				   msg->msg_flags & MSG_DONTWAIT);
+	if (IS_ERR(skb))
+		return skb;
+
+	/* Create L2CAP header */
+	lh = skb_put(skb, L2CAP_HDR_SIZE);
+	lh->cid = cpu_to_le16(chan->dcid);
+	lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
+
+	if (sdulen)
+		put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
+
+	err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
+	if (unlikely(err < 0)) {
+		kfree_skb(skb);
+		return ERR_PTR(err);
+	}
+
+	return skb;
+}
+
+static int l2cap_segment_le_sdu(struct l2cap_chan *chan,
+				struct sk_buff_head *seg_queue,
+				struct msghdr *msg, size_t len)
+{
+	struct sk_buff *skb;
+	size_t pdu_len;
+	u16 sdu_len;
+
+	BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
+
+	sdu_len = len;
+	pdu_len = chan->remote_mps - L2CAP_SDULEN_SIZE;
+
+	while (len > 0) {
+		if (len <= pdu_len)
+			pdu_len = len;
+
+		skb = l2cap_create_le_flowctl_pdu(chan, msg, pdu_len, sdu_len);
+		if (IS_ERR(skb)) {
+			__skb_queue_purge(seg_queue);
+			return PTR_ERR(skb);
+		}
+
+		__skb_queue_tail(seg_queue, skb);
+
+		len -= pdu_len;
+
+		if (sdu_len) {
+			sdu_len = 0;
+			pdu_len += L2CAP_SDULEN_SIZE;
+		}
+	}
+
+	return 0;
+}
+
+static void l2cap_le_flowctl_send(struct l2cap_chan *chan)
+{
+	int sent = 0;
+
+	BT_DBG("chan %p", chan);
+
+	while (chan->tx_credits && !skb_queue_empty(&chan->tx_q)) {
+		l2cap_do_send(chan, skb_dequeue(&chan->tx_q));
+		chan->tx_credits--;
+		sent++;
+	}
+
+	BT_DBG("Sent %d credits %u queued %u", sent, chan->tx_credits,
+	       skb_queue_len(&chan->tx_q));
+}
+
+int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len)
+{
+	struct sk_buff *skb;
+	int err;
+	struct sk_buff_head seg_queue;
+
+	if (!chan->conn)
+		return -ENOTCONN;
+
+	/* Connectionless channel */
+	if (chan->chan_type == L2CAP_CHAN_CONN_LESS) {
+		skb = l2cap_create_connless_pdu(chan, msg, len);
+		if (IS_ERR(skb))
+			return PTR_ERR(skb);
+
+		l2cap_do_send(chan, skb);
+		return len;
+	}
+
+	switch (chan->mode) {
+	case L2CAP_MODE_LE_FLOWCTL:
+	case L2CAP_MODE_EXT_FLOWCTL:
+		/* Check outgoing MTU */
+		if (len > chan->omtu)
+			return -EMSGSIZE;
+
+		__skb_queue_head_init(&seg_queue);
+
+		err = l2cap_segment_le_sdu(chan, &seg_queue, msg, len);
+
+		if (chan->state != BT_CONNECTED) {
+			__skb_queue_purge(&seg_queue);
+			err = -ENOTCONN;
+		}
+
+		if (err)
+			return err;
+
+		skb_queue_splice_tail_init(&seg_queue, &chan->tx_q);
+
+		l2cap_le_flowctl_send(chan);
+
+		if (!chan->tx_credits)
+			chan->ops->suspend(chan);
+
+		err = len;
+
+		break;
+
+	case L2CAP_MODE_BASIC:
+		/* Check outgoing MTU */
+		if (len > chan->omtu)
+			return -EMSGSIZE;
+
+		/* Create a basic PDU */
+		skb = l2cap_create_basic_pdu(chan, msg, len);
+		if (IS_ERR(skb))
+			return PTR_ERR(skb);
+
+		l2cap_do_send(chan, skb);
+		err = len;
+		break;
+
+	case L2CAP_MODE_ERTM:
+	case L2CAP_MODE_STREAMING:
+		/* Check outgoing MTU */
+		if (len > chan->omtu) {
+			err = -EMSGSIZE;
+			break;
+		}
+
+		__skb_queue_head_init(&seg_queue);
+
+		/* Do segmentation before calling in to the state machine,
+		 * since it's possible to block while waiting for memory
+		 * allocation.
+		 */
+		err = l2cap_segment_sdu(chan, &seg_queue, msg, len);
+
+		if (err)
+			break;
+
+		if (chan->mode == L2CAP_MODE_ERTM)
+			l2cap_tx(chan, NULL, &seg_queue, L2CAP_EV_DATA_REQUEST);
+		else
+			l2cap_streaming_send(chan, &seg_queue);
+
+		err = len;
+
+		/* If the skbs were not queued for sending, they'll still be in
+		 * seg_queue and need to be purged.
+		 */
+		__skb_queue_purge(&seg_queue);
+		break;
+
+	default:
+		BT_DBG("bad state %1.1x", chan->mode);
+		err = -EBADFD;
+	}
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(l2cap_chan_send);
+
+static void l2cap_send_srej(struct l2cap_chan *chan, u16 txseq)
+{
+	struct l2cap_ctrl control;
+	u16 seq;
+
+	BT_DBG("chan %p, txseq %u", chan, txseq);
+
+	memset(&control, 0, sizeof(control));
+	control.sframe = 1;
+	control.super = L2CAP_SUPER_SREJ;
+
+	for (seq = chan->expected_tx_seq; seq != txseq;
+	     seq = __next_seq(chan, seq)) {
+		if (!l2cap_ertm_seq_in_queue(&chan->srej_q, seq)) {
+			control.reqseq = seq;
+			l2cap_send_sframe(chan, &control);
+			l2cap_seq_list_append(&chan->srej_list, seq);
+		}
+	}
+
+	chan->expected_tx_seq = __next_seq(chan, txseq);
+}
+
+static void l2cap_send_srej_tail(struct l2cap_chan *chan)
+{
+	struct l2cap_ctrl control;
+
+	BT_DBG("chan %p", chan);
+
+	if (chan->srej_list.tail == L2CAP_SEQ_LIST_CLEAR)
+		return;
+
+	memset(&control, 0, sizeof(control));
+	control.sframe = 1;
+	control.super = L2CAP_SUPER_SREJ;
+	control.reqseq = chan->srej_list.tail;
+	l2cap_send_sframe(chan, &control);
+}
+
+static void l2cap_send_srej_list(struct l2cap_chan *chan, u16 txseq)
+{
+	struct l2cap_ctrl control;
+	u16 initial_head;
+	u16 seq;
+
+	BT_DBG("chan %p, txseq %u", chan, txseq);
+
+	memset(&control, 0, sizeof(control));
+	control.sframe = 1;
+	control.super = L2CAP_SUPER_SREJ;
+
+	/* Capture initial list head to allow only one pass through the list. */
+	initial_head = chan->srej_list.head;
+
+	do {
+		seq = l2cap_seq_list_pop(&chan->srej_list);
+		if (seq == txseq || seq == L2CAP_SEQ_LIST_CLEAR)
+			break;
+
+		control.reqseq = seq;
+		l2cap_send_sframe(chan, &control);
+		l2cap_seq_list_append(&chan->srej_list, seq);
+	} while (chan->srej_list.head != initial_head);
+}
+
+static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq)
+{
+	struct sk_buff *acked_skb;
+	u16 ackseq;
+
+	BT_DBG("chan %p, reqseq %u", chan, reqseq);
+
+	if (chan->unacked_frames == 0 || reqseq == chan->expected_ack_seq)
+		return;
+
+	BT_DBG("expected_ack_seq %u, unacked_frames %u",
+	       chan->expected_ack_seq, chan->unacked_frames);
+
+	for (ackseq = chan->expected_ack_seq; ackseq != reqseq;
+	     ackseq = __next_seq(chan, ackseq)) {
+
+		acked_skb = l2cap_ertm_seq_in_queue(&chan->tx_q, ackseq);
+		if (acked_skb) {
+			skb_unlink(acked_skb, &chan->tx_q);
+			kfree_skb(acked_skb);
+			chan->unacked_frames--;
+		}
+	}
+
+	chan->expected_ack_seq = reqseq;
+
+	if (chan->unacked_frames == 0)
+		__clear_retrans_timer(chan);
+
+	BT_DBG("unacked_frames %u", chan->unacked_frames);
+}
+
+static void l2cap_abort_rx_srej_sent(struct l2cap_chan *chan)
+{
+	BT_DBG("chan %p", chan);
+
+	chan->expected_tx_seq = chan->buffer_seq;
+	l2cap_seq_list_clear(&chan->srej_list);
+	skb_queue_purge(&chan->srej_q);
+	chan->rx_state = L2CAP_RX_STATE_RECV;
+}
+
+static void l2cap_tx_state_xmit(struct l2cap_chan *chan,
+				struct l2cap_ctrl *control,
+				struct sk_buff_head *skbs, u8 event)
+{
+	BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
+	       event);
+
+	switch (event) {
+	case L2CAP_EV_DATA_REQUEST:
+		if (chan->tx_send_head == NULL)
+			chan->tx_send_head = skb_peek(skbs);
+
+		skb_queue_splice_tail_init(skbs, &chan->tx_q);
+		l2cap_ertm_send(chan);
+		break;
+	case L2CAP_EV_LOCAL_BUSY_DETECTED:
+		BT_DBG("Enter LOCAL_BUSY");
+		set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
+
+		if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
+			/* The SREJ_SENT state must be aborted if we are to
+			 * enter the LOCAL_BUSY state.
+			 */
+			l2cap_abort_rx_srej_sent(chan);
+		}
+
+		l2cap_send_ack(chan);
+
+		break;
+	case L2CAP_EV_LOCAL_BUSY_CLEAR:
+		BT_DBG("Exit LOCAL_BUSY");
+		clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
+
+		if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
+			struct l2cap_ctrl local_control;
+
+			memset(&local_control, 0, sizeof(local_control));
+			local_control.sframe = 1;
+			local_control.super = L2CAP_SUPER_RR;
+			local_control.poll = 1;
+			local_control.reqseq = chan->buffer_seq;
+			l2cap_send_sframe(chan, &local_control);
+
+			chan->retry_count = 1;
+			__set_monitor_timer(chan);
+			chan->tx_state = L2CAP_TX_STATE_WAIT_F;
+		}
+		break;
+	case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
+		l2cap_process_reqseq(chan, control->reqseq);
+		break;
+	case L2CAP_EV_EXPLICIT_POLL:
+		l2cap_send_rr_or_rnr(chan, 1);
+		chan->retry_count = 1;
+		__set_monitor_timer(chan);
+		__clear_ack_timer(chan);
+		chan->tx_state = L2CAP_TX_STATE_WAIT_F;
+		break;
+	case L2CAP_EV_RETRANS_TO:
+		l2cap_send_rr_or_rnr(chan, 1);
+		chan->retry_count = 1;
+		__set_monitor_timer(chan);
+		chan->tx_state = L2CAP_TX_STATE_WAIT_F;
+		break;
+	case L2CAP_EV_RECV_FBIT:
+		/* Nothing to process */
+		break;
+	default:
+		break;
+	}
+}
+
+static void l2cap_tx_state_wait_f(struct l2cap_chan *chan,
+				  struct l2cap_ctrl *control,
+				  struct sk_buff_head *skbs, u8 event)
+{
+	BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
+	       event);
+
+	switch (event) {
+	case L2CAP_EV_DATA_REQUEST:
+		if (chan->tx_send_head == NULL)
+			chan->tx_send_head = skb_peek(skbs);
+		/* Queue data, but don't send. */
+		skb_queue_splice_tail_init(skbs, &chan->tx_q);
+		break;
+	case L2CAP_EV_LOCAL_BUSY_DETECTED:
+		BT_DBG("Enter LOCAL_BUSY");
+		set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
+
+		if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
+			/* The SREJ_SENT state must be aborted if we are to
+			 * enter the LOCAL_BUSY state.
+			 */
+			l2cap_abort_rx_srej_sent(chan);
+		}
+
+		l2cap_send_ack(chan);
+
+		break;
+	case L2CAP_EV_LOCAL_BUSY_CLEAR:
+		BT_DBG("Exit LOCAL_BUSY");
+		clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
+
+		if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
+			struct l2cap_ctrl local_control;
+			memset(&local_control, 0, sizeof(local_control));
+			local_control.sframe = 1;
+			local_control.super = L2CAP_SUPER_RR;
+			local_control.poll = 1;
+			local_control.reqseq = chan->buffer_seq;
+			l2cap_send_sframe(chan, &local_control);
+
+			chan->retry_count = 1;
+			__set_monitor_timer(chan);
+			chan->tx_state = L2CAP_TX_STATE_WAIT_F;
+		}
+		break;
+	case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
+		l2cap_process_reqseq(chan, control->reqseq);
+		fallthrough;
+
+	case L2CAP_EV_RECV_FBIT:
+		if (control && control->final) {
+			__clear_monitor_timer(chan);
+			if (chan->unacked_frames > 0)
+				__set_retrans_timer(chan);
+			chan->retry_count = 0;
+			chan->tx_state = L2CAP_TX_STATE_XMIT;
+			BT_DBG("recv fbit tx_state 0x2.2%x", chan->tx_state);
+		}
+		break;
+	case L2CAP_EV_EXPLICIT_POLL:
+		/* Ignore */
+		break;
+	case L2CAP_EV_MONITOR_TO:
+		if (chan->max_tx == 0 || chan->retry_count < chan->max_tx) {
+			l2cap_send_rr_or_rnr(chan, 1);
+			__set_monitor_timer(chan);
+			chan->retry_count++;
+		} else {
+			l2cap_send_disconn_req(chan, ECONNABORTED);
+		}
+		break;
+	default:
+		break;
+	}
+}
+
+static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
+		     struct sk_buff_head *skbs, u8 event)
+{
+	BT_DBG("chan %p, control %p, skbs %p, event %d, state %d",
+	       chan, control, skbs, event, chan->tx_state);
+
+	switch (chan->tx_state) {
+	case L2CAP_TX_STATE_XMIT:
+		l2cap_tx_state_xmit(chan, control, skbs, event);
+		break;
+	case L2CAP_TX_STATE_WAIT_F:
+		l2cap_tx_state_wait_f(chan, control, skbs, event);
+		break;
+	default:
+		/* Ignore event */
+		break;
+	}
+}
+
+static void l2cap_pass_to_tx(struct l2cap_chan *chan,
+			     struct l2cap_ctrl *control)
+{
+	BT_DBG("chan %p, control %p", chan, control);
+	l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_REQSEQ_AND_FBIT);
+}
+
+static void l2cap_pass_to_tx_fbit(struct l2cap_chan *chan,
+				  struct l2cap_ctrl *control)
+{
+	BT_DBG("chan %p, control %p", chan, control);
+	l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_FBIT);
+}
+
+/* Copy frame to all raw sockets on that connection */
+static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
+{
+	struct sk_buff *nskb;
+	struct l2cap_chan *chan;
+
+	BT_DBG("conn %p", conn);
+
+	mutex_lock(&conn->chan_lock);
+
+	list_for_each_entry(chan, &conn->chan_l, list) {
+		if (chan->chan_type != L2CAP_CHAN_RAW)
+			continue;
+
+		/* Don't send frame to the channel it came from */
+		if (bt_cb(skb)->l2cap.chan == chan)
+			continue;
+
+		nskb = skb_clone(skb, GFP_KERNEL);
+		if (!nskb)
+			continue;
+		if (chan->ops->recv(chan, nskb))
+			kfree_skb(nskb);
+	}
+
+	mutex_unlock(&conn->chan_lock);
+}
+
+/* ---- L2CAP signalling commands ---- */
+static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code,
+				       u8 ident, u16 dlen, void *data)
+{
+	struct sk_buff *skb, **frag;
+	struct l2cap_cmd_hdr *cmd;
+	struct l2cap_hdr *lh;
+	int len, count;
+
+	BT_DBG("conn %p, code 0x%2.2x, ident 0x%2.2x, len %u",
+	       conn, code, ident, dlen);
+
+	if (conn->mtu < L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE)
+		return NULL;
+
+	len = L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE + dlen;
+	count = min_t(unsigned int, conn->mtu, len);
+
+	skb = bt_skb_alloc(count, GFP_KERNEL);
+	if (!skb)
+		return NULL;
+
+	lh = skb_put(skb, L2CAP_HDR_SIZE);
+	lh->len = cpu_to_le16(L2CAP_CMD_HDR_SIZE + dlen);
+
+	if (conn->hcon->type == LE_LINK)
+		lh->cid = cpu_to_le16(L2CAP_CID_LE_SIGNALING);
+	else
+		lh->cid = cpu_to_le16(L2CAP_CID_SIGNALING);
+
+	cmd = skb_put(skb, L2CAP_CMD_HDR_SIZE);
+	cmd->code  = code;
+	cmd->ident = ident;
+	cmd->len   = cpu_to_le16(dlen);
+
+	if (dlen) {
+		count -= L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE;
+		skb_put_data(skb, data, count);
+		data += count;
+	}
+
+	len -= skb->len;
+
+	/* Continuation fragments (no L2CAP header) */
+	frag = &skb_shinfo(skb)->frag_list;
+	while (len) {
+		count = min_t(unsigned int, conn->mtu, len);
+
+		*frag = bt_skb_alloc(count, GFP_KERNEL);
+		if (!*frag)
+			goto fail;
+
+		skb_put_data(*frag, data, count);
+
+		len  -= count;
+		data += count;
+
+		frag = &(*frag)->next;
+	}
+
+	return skb;
+
+fail:
+	kfree_skb(skb);
+	return NULL;
+}
+
+static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen,
+				     unsigned long *val)
+{
+	struct l2cap_conf_opt *opt = *ptr;
+	int len;
+
+	len = L2CAP_CONF_OPT_SIZE + opt->len;
+	*ptr += len;
+
+	*type = opt->type;
+	*olen = opt->len;
+
+	switch (opt->len) {
+	case 1:
+		*val = *((u8 *) opt->val);
+		break;
+
+	case 2:
+		*val = get_unaligned_le16(opt->val);
+		break;
+
+	case 4:
+		*val = get_unaligned_le32(opt->val);
+		break;
+
+	default:
+		*val = (unsigned long) opt->val;
+		break;
+	}
+
+	BT_DBG("type 0x%2.2x len %u val 0x%lx", *type, opt->len, *val);
+	return len;
+}
+
+static void l2cap_add_conf_opt(void **ptr, u8 type, u8 len, unsigned long val, size_t size)
+{
+	struct l2cap_conf_opt *opt = *ptr;
+
+	BT_DBG("type 0x%2.2x len %u val 0x%lx", type, len, val);
+
+	if (size < L2CAP_CONF_OPT_SIZE + len)
+		return;
+
+	opt->type = type;
+	opt->len  = len;
+
+	switch (len) {
+	case 1:
+		*((u8 *) opt->val)  = val;
+		break;
+
+	case 2:
+		put_unaligned_le16(val, opt->val);
+		break;
+
+	case 4:
+		put_unaligned_le32(val, opt->val);
+		break;
+
+	default:
+		memcpy(opt->val, (void *) val, len);
+		break;
+	}
+
+	*ptr += L2CAP_CONF_OPT_SIZE + len;
+}
+
+static void l2cap_add_opt_efs(void **ptr, struct l2cap_chan *chan, size_t size)
+{
+	struct l2cap_conf_efs efs;
+
+	switch (chan->mode) {
+	case L2CAP_MODE_ERTM:
+		efs.id		= chan->local_id;
+		efs.stype	= chan->local_stype;
+		efs.msdu	= cpu_to_le16(chan->local_msdu);
+		efs.sdu_itime	= cpu_to_le32(chan->local_sdu_itime);
+		efs.acc_lat	= cpu_to_le32(L2CAP_DEFAULT_ACC_LAT);
+		efs.flush_to	= cpu_to_le32(L2CAP_EFS_DEFAULT_FLUSH_TO);
+		break;
+
+	case L2CAP_MODE_STREAMING:
+		efs.id		= 1;
+		efs.stype	= L2CAP_SERV_BESTEFFORT;
+		efs.msdu	= cpu_to_le16(chan->local_msdu);
+		efs.sdu_itime	= cpu_to_le32(chan->local_sdu_itime);
+		efs.acc_lat	= 0;
+		efs.flush_to	= 0;
+		break;
+
+	default:
+		return;
+	}
+
+	l2cap_add_conf_opt(ptr, L2CAP_CONF_EFS, sizeof(efs),
+			   (unsigned long) &efs, size);
+}
+
+static void l2cap_ack_timeout(struct work_struct *work)
+{
+	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
+					       ack_timer.work);
+	u16 frames_to_ack;
+
+	BT_DBG("chan %p", chan);
+
+	l2cap_chan_lock(chan);
+
+	frames_to_ack = __seq_offset(chan, chan->buffer_seq,
+				     chan->last_acked_seq);
+
+	if (frames_to_ack)
+		l2cap_send_rr_or_rnr(chan, 0);
+
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+}
+
+int l2cap_ertm_init(struct l2cap_chan *chan)
+{
+	int err;
+
+	chan->next_tx_seq = 0;
+	chan->expected_tx_seq = 0;
+	chan->expected_ack_seq = 0;
+	chan->unacked_frames = 0;
+	chan->buffer_seq = 0;
+	chan->frames_sent = 0;
+	chan->last_acked_seq = 0;
+	chan->sdu = NULL;
+	chan->sdu_last_frag = NULL;
+	chan->sdu_len = 0;
+
+	skb_queue_head_init(&chan->tx_q);
+
+	chan->local_amp_id = AMP_ID_BREDR;
+	chan->move_id = AMP_ID_BREDR;
+	chan->move_state = L2CAP_MOVE_STABLE;
+	chan->move_role = L2CAP_MOVE_ROLE_NONE;
+
+	if (chan->mode != L2CAP_MODE_ERTM)
+		return 0;
+
+	chan->rx_state = L2CAP_RX_STATE_RECV;
+	chan->tx_state = L2CAP_TX_STATE_XMIT;
+
+	skb_queue_head_init(&chan->srej_q);
+
+	err = l2cap_seq_list_init(&chan->srej_list, chan->tx_win);
+	if (err < 0)
+		return err;
+
+	err = l2cap_seq_list_init(&chan->retrans_list, chan->remote_tx_win);
+	if (err < 0)
+		l2cap_seq_list_free(&chan->srej_list);
+
+	return err;
+}
+
+static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask)
+{
+	switch (mode) {
+	case L2CAP_MODE_STREAMING:
+	case L2CAP_MODE_ERTM:
+		if (l2cap_mode_supported(mode, remote_feat_mask))
+			return mode;
+		fallthrough;
+	default:
+		return L2CAP_MODE_BASIC;
+	}
+}
+
+static inline bool __l2cap_ews_supported(struct l2cap_conn *conn)
+{
+	return ((conn->local_fixed_chan & L2CAP_FC_A2MP) &&
+		(conn->feat_mask & L2CAP_FEAT_EXT_WINDOW));
+}
+
+static inline bool __l2cap_efs_supported(struct l2cap_conn *conn)
+{
+	return ((conn->local_fixed_chan & L2CAP_FC_A2MP) &&
+		(conn->feat_mask & L2CAP_FEAT_EXT_FLOW));
+}
+
+static void __l2cap_set_ertm_timeouts(struct l2cap_chan *chan,
+				      struct l2cap_conf_rfc *rfc)
+{
+	if (chan->local_amp_id != AMP_ID_BREDR && chan->hs_hcon) {
+		u64 ertm_to = chan->hs_hcon->hdev->amp_be_flush_to;
+
+		/* Class 1 devices have must have ERTM timeouts
+		 * exceeding the Link Supervision Timeout.  The
+		 * default Link Supervision Timeout for AMP
+		 * controllers is 10 seconds.
+		 *
+		 * Class 1 devices use 0xffffffff for their
+		 * best-effort flush timeout, so the clamping logic
+		 * will result in a timeout that meets the above
+		 * requirement.  ERTM timeouts are 16-bit values, so
+		 * the maximum timeout is 65.535 seconds.
+		 */
+
+		/* Convert timeout to milliseconds and round */
+		ertm_to = DIV_ROUND_UP_ULL(ertm_to, 1000);
+
+		/* This is the recommended formula for class 2 devices
+		 * that start ERTM timers when packets are sent to the
+		 * controller.
+		 */
+		ertm_to = 3 * ertm_to + 500;
+
+		if (ertm_to > 0xffff)
+			ertm_to = 0xffff;
+
+		rfc->retrans_timeout = cpu_to_le16((u16) ertm_to);
+		rfc->monitor_timeout = rfc->retrans_timeout;
+	} else {
+		rfc->retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO);
+		rfc->monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO);
+	}
+}
+
+static inline void l2cap_txwin_setup(struct l2cap_chan *chan)
+{
+	if (chan->tx_win > L2CAP_DEFAULT_TX_WINDOW &&
+	    __l2cap_ews_supported(chan->conn)) {
+		/* use extended control field */
+		set_bit(FLAG_EXT_CTRL, &chan->flags);
+		chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW;
+	} else {
+		chan->tx_win = min_t(u16, chan->tx_win,
+				     L2CAP_DEFAULT_TX_WINDOW);
+		chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
+	}
+	chan->ack_win = chan->tx_win;
+}
+
+static void l2cap_mtu_auto(struct l2cap_chan *chan)
+{
+	struct hci_conn *conn = chan->conn->hcon;
+
+	chan->imtu = L2CAP_DEFAULT_MIN_MTU;
+
+	/* The 2-DH1 packet has between 2 and 56 information bytes
+	 * (including the 2-byte payload header)
+	 */
+	if (!(conn->pkt_type & HCI_2DH1))
+		chan->imtu = 54;
+
+	/* The 3-DH1 packet has between 2 and 85 information bytes
+	 * (including the 2-byte payload header)
+	 */
+	if (!(conn->pkt_type & HCI_3DH1))
+		chan->imtu = 83;
+
+	/* The 2-DH3 packet has between 2 and 369 information bytes
+	 * (including the 2-byte payload header)
+	 */
+	if (!(conn->pkt_type & HCI_2DH3))
+		chan->imtu = 367;
+
+	/* The 3-DH3 packet has between 2 and 554 information bytes
+	 * (including the 2-byte payload header)
+	 */
+	if (!(conn->pkt_type & HCI_3DH3))
+		chan->imtu = 552;
+
+	/* The 2-DH5 packet has between 2 and 681 information bytes
+	 * (including the 2-byte payload header)
+	 */
+	if (!(conn->pkt_type & HCI_2DH5))
+		chan->imtu = 679;
+
+	/* The 3-DH5 packet has between 2 and 1023 information bytes
+	 * (including the 2-byte payload header)
+	 */
+	if (!(conn->pkt_type & HCI_3DH5))
+		chan->imtu = 1021;
+}
+
+static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size)
+{
+	struct l2cap_conf_req *req = data;
+	struct l2cap_conf_rfc rfc = { .mode = chan->mode };
+	void *ptr = req->data;
+	void *endptr = data + data_size;
+	u16 size;
+
+	BT_DBG("chan %p", chan);
+
+	if (chan->num_conf_req || chan->num_conf_rsp)
+		goto done;
+
+	switch (chan->mode) {
+	case L2CAP_MODE_STREAMING:
+	case L2CAP_MODE_ERTM:
+		if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state))
+			break;
+
+		if (__l2cap_efs_supported(chan->conn))
+			set_bit(FLAG_EFS_ENABLE, &chan->flags);
+
+		fallthrough;
+	default:
+		chan->mode = l2cap_select_mode(rfc.mode, chan->conn->feat_mask);
+		break;
+	}
+
+done:
+	if (chan->imtu != L2CAP_DEFAULT_MTU) {
+		if (!chan->imtu)
+			l2cap_mtu_auto(chan);
+		l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu,
+				   endptr - ptr);
+	}
+
+	switch (chan->mode) {
+	case L2CAP_MODE_BASIC:
+		if (disable_ertm)
+			break;
+
+		if (!(chan->conn->feat_mask & L2CAP_FEAT_ERTM) &&
+		    !(chan->conn->feat_mask & L2CAP_FEAT_STREAMING))
+			break;
+
+		rfc.mode            = L2CAP_MODE_BASIC;
+		rfc.txwin_size      = 0;
+		rfc.max_transmit    = 0;
+		rfc.retrans_timeout = 0;
+		rfc.monitor_timeout = 0;
+		rfc.max_pdu_size    = 0;
+
+		l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
+				   (unsigned long) &rfc, endptr - ptr);
+		break;
+
+	case L2CAP_MODE_ERTM:
+		rfc.mode            = L2CAP_MODE_ERTM;
+		rfc.max_transmit    = chan->max_tx;
+
+		__l2cap_set_ertm_timeouts(chan, &rfc);
+
+		size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
+			     L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
+			     L2CAP_FCS_SIZE);
+		rfc.max_pdu_size = cpu_to_le16(size);
+
+		l2cap_txwin_setup(chan);
+
+		rfc.txwin_size = min_t(u16, chan->tx_win,
+				       L2CAP_DEFAULT_TX_WINDOW);
+
+		l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
+				   (unsigned long) &rfc, endptr - ptr);
+
+		if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
+			l2cap_add_opt_efs(&ptr, chan, endptr - ptr);
+
+		if (test_bit(FLAG_EXT_CTRL, &chan->flags))
+			l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
+					   chan->tx_win, endptr - ptr);
+
+		if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
+			if (chan->fcs == L2CAP_FCS_NONE ||
+			    test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
+				chan->fcs = L2CAP_FCS_NONE;
+				l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
+						   chan->fcs, endptr - ptr);
+			}
+		break;
+
+	case L2CAP_MODE_STREAMING:
+		l2cap_txwin_setup(chan);
+		rfc.mode            = L2CAP_MODE_STREAMING;
+		rfc.txwin_size      = 0;
+		rfc.max_transmit    = 0;
+		rfc.retrans_timeout = 0;
+		rfc.monitor_timeout = 0;
+
+		size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
+			     L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
+			     L2CAP_FCS_SIZE);
+		rfc.max_pdu_size = cpu_to_le16(size);
+
+		l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
+				   (unsigned long) &rfc, endptr - ptr);
+
+		if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
+			l2cap_add_opt_efs(&ptr, chan, endptr - ptr);
+
+		if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
+			if (chan->fcs == L2CAP_FCS_NONE ||
+			    test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
+				chan->fcs = L2CAP_FCS_NONE;
+				l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
+						   chan->fcs, endptr - ptr);
+			}
+		break;
+	}
+
+	req->dcid  = cpu_to_le16(chan->dcid);
+	req->flags = cpu_to_le16(0);
+
+	return ptr - data;
+}
+
+static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data_size)
+{
+	struct l2cap_conf_rsp *rsp = data;
+	void *ptr = rsp->data;
+	void *endptr = data + data_size;
+	void *req = chan->conf_req;
+	int len = chan->conf_len;
+	int type, hint, olen;
+	unsigned long val;
+	struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
+	struct l2cap_conf_efs efs;
+	u8 remote_efs = 0;
+	u16 mtu = L2CAP_DEFAULT_MTU;
+	u16 result = L2CAP_CONF_SUCCESS;
+	u16 size;
+
+	BT_DBG("chan %p", chan);
+
+	while (len >= L2CAP_CONF_OPT_SIZE) {
+		len -= l2cap_get_conf_opt(&req, &type, &olen, &val);
+		if (len < 0)
+			break;
+
+		hint  = type & L2CAP_CONF_HINT;
+		type &= L2CAP_CONF_MASK;
+
+		switch (type) {
+		case L2CAP_CONF_MTU:
+			if (olen != 2)
+				break;
+			mtu = val;
+			break;
+
+		case L2CAP_CONF_FLUSH_TO:
+			if (olen != 2)
+				break;
+			chan->flush_to = val;
+			break;
+
+		case L2CAP_CONF_QOS:
+			break;
+
+		case L2CAP_CONF_RFC:
+			if (olen != sizeof(rfc))
+				break;
+			memcpy(&rfc, (void *) val, olen);
+			break;
+
+		case L2CAP_CONF_FCS:
+			if (olen != 1)
+				break;
+			if (val == L2CAP_FCS_NONE)
+				set_bit(CONF_RECV_NO_FCS, &chan->conf_state);
+			break;
+
+		case L2CAP_CONF_EFS:
+			if (olen != sizeof(efs))
+				break;
+			remote_efs = 1;
+			memcpy(&efs, (void *) val, olen);
+			break;
+
+		case L2CAP_CONF_EWS:
+			if (olen != 2)
+				break;
+			if (!(chan->conn->local_fixed_chan & L2CAP_FC_A2MP))
+				return -ECONNREFUSED;
+			set_bit(FLAG_EXT_CTRL, &chan->flags);
+			set_bit(CONF_EWS_RECV, &chan->conf_state);
+			chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW;
+			chan->remote_tx_win = val;
+			break;
+
+		default:
+			if (hint)
+				break;
+			result = L2CAP_CONF_UNKNOWN;
+			l2cap_add_conf_opt(&ptr, (u8)type, sizeof(u8), type, endptr - ptr);
+			break;
+		}
+	}
+
+	if (chan->num_conf_rsp || chan->num_conf_req > 1)
+		goto done;
+
+	switch (chan->mode) {
+	case L2CAP_MODE_STREAMING:
+	case L2CAP_MODE_ERTM:
+		if (!test_bit(CONF_STATE2_DEVICE, &chan->conf_state)) {
+			chan->mode = l2cap_select_mode(rfc.mode,
+						       chan->conn->feat_mask);
+			break;
+		}
+
+		if (remote_efs) {
+			if (__l2cap_efs_supported(chan->conn))
+				set_bit(FLAG_EFS_ENABLE, &chan->flags);
+			else
+				return -ECONNREFUSED;
+		}
+
+		if (chan->mode != rfc.mode)
+			return -ECONNREFUSED;
+
+		break;
+	}
+
+done:
+	if (chan->mode != rfc.mode) {
+		result = L2CAP_CONF_UNACCEPT;
+		rfc.mode = chan->mode;
+
+		if (chan->num_conf_rsp == 1)
+			return -ECONNREFUSED;
+
+		l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
+				   (unsigned long) &rfc, endptr - ptr);
+	}
+
+	if (result == L2CAP_CONF_SUCCESS) {
+		/* Configure output options and let the other side know
+		 * which ones we don't like. */
+
+		if (mtu < L2CAP_DEFAULT_MIN_MTU)
+			result = L2CAP_CONF_UNACCEPT;
+		else {
+			chan->omtu = mtu;
+			set_bit(CONF_MTU_DONE, &chan->conf_state);
+		}
+		l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->omtu, endptr - ptr);
+
+		if (remote_efs) {
+			if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
+			    efs.stype != L2CAP_SERV_NOTRAFIC &&
+			    efs.stype != chan->local_stype) {
+
+				result = L2CAP_CONF_UNACCEPT;
+
+				if (chan->num_conf_req >= 1)
+					return -ECONNREFUSED;
+
+				l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
+						   sizeof(efs),
+						   (unsigned long) &efs, endptr - ptr);
+			} else {
+				/* Send PENDING Conf Rsp */
+				result = L2CAP_CONF_PENDING;
+				set_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
+			}
+		}
+
+		switch (rfc.mode) {
+		case L2CAP_MODE_BASIC:
+			chan->fcs = L2CAP_FCS_NONE;
+			set_bit(CONF_MODE_DONE, &chan->conf_state);
+			break;
+
+		case L2CAP_MODE_ERTM:
+			if (!test_bit(CONF_EWS_RECV, &chan->conf_state))
+				chan->remote_tx_win = rfc.txwin_size;
+			else
+				rfc.txwin_size = L2CAP_DEFAULT_TX_WINDOW;
+
+			chan->remote_max_tx = rfc.max_transmit;
+
+			size = min_t(u16, le16_to_cpu(rfc.max_pdu_size),
+				     chan->conn->mtu - L2CAP_EXT_HDR_SIZE -
+				     L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE);
+			rfc.max_pdu_size = cpu_to_le16(size);
+			chan->remote_mps = size;
+
+			__l2cap_set_ertm_timeouts(chan, &rfc);
+
+			set_bit(CONF_MODE_DONE, &chan->conf_state);
+
+			l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
+					   sizeof(rfc), (unsigned long) &rfc, endptr - ptr);
+
+			if (remote_efs &&
+			    test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
+				chan->remote_id = efs.id;
+				chan->remote_stype = efs.stype;
+				chan->remote_msdu = le16_to_cpu(efs.msdu);
+				chan->remote_flush_to =
+					le32_to_cpu(efs.flush_to);
+				chan->remote_acc_lat =
+					le32_to_cpu(efs.acc_lat);
+				chan->remote_sdu_itime =
+					le32_to_cpu(efs.sdu_itime);
+				l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
+						   sizeof(efs),
+						   (unsigned long) &efs, endptr - ptr);
+			}
+			break;
+
+		case L2CAP_MODE_STREAMING:
+			size = min_t(u16, le16_to_cpu(rfc.max_pdu_size),
+				     chan->conn->mtu - L2CAP_EXT_HDR_SIZE -
+				     L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE);
+			rfc.max_pdu_size = cpu_to_le16(size);
+			chan->remote_mps = size;
+
+			set_bit(CONF_MODE_DONE, &chan->conf_state);
+
+			l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
+					   (unsigned long) &rfc, endptr - ptr);
+
+			break;
+
+		default:
+			result = L2CAP_CONF_UNACCEPT;
+
+			memset(&rfc, 0, sizeof(rfc));
+			rfc.mode = chan->mode;
+		}
+
+		if (result == L2CAP_CONF_SUCCESS)
+			set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
+	}
+	rsp->scid   = cpu_to_le16(chan->dcid);
+	rsp->result = cpu_to_le16(result);
+	rsp->flags  = cpu_to_le16(0);
+
+	return ptr - data;
+}
+
+static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len,
+				void *data, size_t size, u16 *result)
+{
+	struct l2cap_conf_req *req = data;
+	void *ptr = req->data;
+	void *endptr = data + size;
+	int type, olen;
+	unsigned long val;
+	struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
+	struct l2cap_conf_efs efs;
+
+	BT_DBG("chan %p, rsp %p, len %d, req %p", chan, rsp, len, data);
+
+	while (len >= L2CAP_CONF_OPT_SIZE) {
+		len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
+		if (len < 0)
+			break;
+
+		switch (type) {
+		case L2CAP_CONF_MTU:
+			if (olen != 2)
+				break;
+			if (val < L2CAP_DEFAULT_MIN_MTU) {
+				*result = L2CAP_CONF_UNACCEPT;
+				chan->imtu = L2CAP_DEFAULT_MIN_MTU;
+			} else
+				chan->imtu = val;
+			l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu,
+					   endptr - ptr);
+			break;
+
+		case L2CAP_CONF_FLUSH_TO:
+			if (olen != 2)
+				break;
+			chan->flush_to = val;
+			l2cap_add_conf_opt(&ptr, L2CAP_CONF_FLUSH_TO, 2,
+					   chan->flush_to, endptr - ptr);
+			break;
+
+		case L2CAP_CONF_RFC:
+			if (olen != sizeof(rfc))
+				break;
+			memcpy(&rfc, (void *)val, olen);
+			if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state) &&
+			    rfc.mode != chan->mode)
+				return -ECONNREFUSED;
+			chan->fcs = 0;
+			l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
+					   (unsigned long) &rfc, endptr - ptr);
+			break;
+
+		case L2CAP_CONF_EWS:
+			if (olen != 2)
+				break;
+			chan->ack_win = min_t(u16, val, chan->ack_win);
+			l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
+					   chan->tx_win, endptr - ptr);
+			break;
+
+		case L2CAP_CONF_EFS:
+			if (olen != sizeof(efs))
+				break;
+			memcpy(&efs, (void *)val, olen);
+			if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
+			    efs.stype != L2CAP_SERV_NOTRAFIC &&
+			    efs.stype != chan->local_stype)
+				return -ECONNREFUSED;
+			l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs),
+					   (unsigned long) &efs, endptr - ptr);
+			break;
+
+		case L2CAP_CONF_FCS:
+			if (olen != 1)
+				break;
+			if (*result == L2CAP_CONF_PENDING)
+				if (val == L2CAP_FCS_NONE)
+					set_bit(CONF_RECV_NO_FCS,
+						&chan->conf_state);
+			break;
+		}
+	}
+
+	if (chan->mode == L2CAP_MODE_BASIC && chan->mode != rfc.mode)
+		return -ECONNREFUSED;
+
+	chan->mode = rfc.mode;
+
+	if (*result == L2CAP_CONF_SUCCESS || *result == L2CAP_CONF_PENDING) {
+		switch (rfc.mode) {
+		case L2CAP_MODE_ERTM:
+			chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
+			chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
+			chan->mps    = le16_to_cpu(rfc.max_pdu_size);
+			if (!test_bit(FLAG_EXT_CTRL, &chan->flags))
+				chan->ack_win = min_t(u16, chan->ack_win,
+						      rfc.txwin_size);
+
+			if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
+				chan->local_msdu = le16_to_cpu(efs.msdu);
+				chan->local_sdu_itime =
+					le32_to_cpu(efs.sdu_itime);
+				chan->local_acc_lat = le32_to_cpu(efs.acc_lat);
+				chan->local_flush_to =
+					le32_to_cpu(efs.flush_to);
+			}
+			break;
+
+		case L2CAP_MODE_STREAMING:
+			chan->mps    = le16_to_cpu(rfc.max_pdu_size);
+		}
+	}
+
+	req->dcid   = cpu_to_le16(chan->dcid);
+	req->flags  = cpu_to_le16(0);
+
+	return ptr - data;
+}
+
+static int l2cap_build_conf_rsp(struct l2cap_chan *chan, void *data,
+				u16 result, u16 flags)
+{
+	struct l2cap_conf_rsp *rsp = data;
+	void *ptr = rsp->data;
+
+	BT_DBG("chan %p", chan);
+
+	rsp->scid   = cpu_to_le16(chan->dcid);
+	rsp->result = cpu_to_le16(result);
+	rsp->flags  = cpu_to_le16(flags);
+
+	return ptr - data;
+}
+
+void __l2cap_le_connect_rsp_defer(struct l2cap_chan *chan)
+{
+	struct l2cap_le_conn_rsp rsp;
+	struct l2cap_conn *conn = chan->conn;
+
+	BT_DBG("chan %p", chan);
+
+	rsp.dcid    = cpu_to_le16(chan->scid);
+	rsp.mtu     = cpu_to_le16(chan->imtu);
+	rsp.mps     = cpu_to_le16(chan->mps);
+	rsp.credits = cpu_to_le16(chan->rx_credits);
+	rsp.result  = cpu_to_le16(L2CAP_CR_LE_SUCCESS);
+
+	l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
+		       &rsp);
+}
+
+static void l2cap_ecred_list_defer(struct l2cap_chan *chan, void *data)
+{
+	int *result = data;
+
+	if (*result || test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
+		return;
+
+	switch (chan->state) {
+	case BT_CONNECT2:
+		/* If channel still pending accept add to result */
+		(*result)++;
+		return;
+	case BT_CONNECTED:
+		return;
+	default:
+		/* If not connected or pending accept it has been refused */
+		*result = -ECONNREFUSED;
+		return;
+	}
+}
+
+struct l2cap_ecred_rsp_data {
+	struct {
+		struct l2cap_ecred_conn_rsp rsp;
+		__le16 scid[L2CAP_ECRED_MAX_CID];
+	} __packed pdu;
+	int count;
+};
+
+static void l2cap_ecred_rsp_defer(struct l2cap_chan *chan, void *data)
+{
+	struct l2cap_ecred_rsp_data *rsp = data;
+
+	if (test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
+		return;
+
+	/* Reset ident so only one response is sent */
+	chan->ident = 0;
+
+	/* Include all channels pending with the same ident */
+	if (!rsp->pdu.rsp.result)
+		rsp->pdu.rsp.dcid[rsp->count++] = cpu_to_le16(chan->scid);
+	else
+		l2cap_chan_del(chan, ECONNRESET);
+}
+
+void __l2cap_ecred_conn_rsp_defer(struct l2cap_chan *chan)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct l2cap_ecred_rsp_data data;
+	u16 id = chan->ident;
+	int result = 0;
+
+	if (!id)
+		return;
+
+	BT_DBG("chan %p id %d", chan, id);
+
+	memset(&data, 0, sizeof(data));
+
+	data.pdu.rsp.mtu     = cpu_to_le16(chan->imtu);
+	data.pdu.rsp.mps     = cpu_to_le16(chan->mps);
+	data.pdu.rsp.credits = cpu_to_le16(chan->rx_credits);
+	data.pdu.rsp.result  = cpu_to_le16(L2CAP_CR_LE_SUCCESS);
+
+	/* Verify that all channels are ready */
+	__l2cap_chan_list_id(conn, id, l2cap_ecred_list_defer, &result);
+
+	if (result > 0)
+		return;
+
+	if (result < 0)
+		data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_AUTHORIZATION);
+
+	/* Build response */
+	__l2cap_chan_list_id(conn, id, l2cap_ecred_rsp_defer, &data);
+
+	l2cap_send_cmd(conn, id, L2CAP_ECRED_CONN_RSP,
+		       sizeof(data.pdu.rsp) + (data.count * sizeof(__le16)),
+		       &data.pdu);
+}
+
+void __l2cap_connect_rsp_defer(struct l2cap_chan *chan)
+{
+	struct l2cap_conn_rsp rsp;
+	struct l2cap_conn *conn = chan->conn;
+	u8 buf[128];
+	u8 rsp_code;
+
+	rsp.scid   = cpu_to_le16(chan->dcid);
+	rsp.dcid   = cpu_to_le16(chan->scid);
+	rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
+	rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
+
+	if (chan->hs_hcon)
+		rsp_code = L2CAP_CREATE_CHAN_RSP;
+	else
+		rsp_code = L2CAP_CONN_RSP;
+
+	BT_DBG("chan %p rsp_code %u", chan, rsp_code);
+
+	l2cap_send_cmd(conn, chan->ident, rsp_code, sizeof(rsp), &rsp);
+
+	if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
+		return;
+
+	l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
+		       l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
+	chan->num_conf_req++;
+}
+
+static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len)
+{
+	int type, olen;
+	unsigned long val;
+	/* Use sane default values in case a misbehaving remote device
+	 * did not send an RFC or extended window size option.
+	 */
+	u16 txwin_ext = chan->ack_win;
+	struct l2cap_conf_rfc rfc = {
+		.mode = chan->mode,
+		.retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO),
+		.monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO),
+		.max_pdu_size = cpu_to_le16(chan->imtu),
+		.txwin_size = min_t(u16, chan->ack_win, L2CAP_DEFAULT_TX_WINDOW),
+	};
+
+	BT_DBG("chan %p, rsp %p, len %d", chan, rsp, len);
+
+	if ((chan->mode != L2CAP_MODE_ERTM) && (chan->mode != L2CAP_MODE_STREAMING))
+		return;
+
+	while (len >= L2CAP_CONF_OPT_SIZE) {
+		len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
+		if (len < 0)
+			break;
+
+		switch (type) {
+		case L2CAP_CONF_RFC:
+			if (olen != sizeof(rfc))
+				break;
+			memcpy(&rfc, (void *)val, olen);
+			break;
+		case L2CAP_CONF_EWS:
+			if (olen != 2)
+				break;
+			txwin_ext = val;
+			break;
+		}
+	}
+
+	switch (rfc.mode) {
+	case L2CAP_MODE_ERTM:
+		chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
+		chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
+		chan->mps = le16_to_cpu(rfc.max_pdu_size);
+		if (test_bit(FLAG_EXT_CTRL, &chan->flags))
+			chan->ack_win = min_t(u16, chan->ack_win, txwin_ext);
+		else
+			chan->ack_win = min_t(u16, chan->ack_win,
+					      rfc.txwin_size);
+		break;
+	case L2CAP_MODE_STREAMING:
+		chan->mps    = le16_to_cpu(rfc.max_pdu_size);
+	}
+}
+
+static inline int l2cap_command_rej(struct l2cap_conn *conn,
+				    struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				    u8 *data)
+{
+	struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
+
+	if (cmd_len < sizeof(*rej))
+		return -EPROTO;
+
+	if (rej->reason != L2CAP_REJ_NOT_UNDERSTOOD)
+		return 0;
+
+	if ((conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) &&
+	    cmd->ident == conn->info_ident) {
+		cancel_delayed_work(&conn->info_timer);
+
+		conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
+		conn->info_ident = 0;
+
+		l2cap_conn_start(conn);
+	}
+
+	return 0;
+}
+
+static struct l2cap_chan *l2cap_connect(struct l2cap_conn *conn,
+					struct l2cap_cmd_hdr *cmd,
+					u8 *data, u8 rsp_code, u8 amp_id)
+{
+	struct l2cap_conn_req *req = (struct l2cap_conn_req *) data;
+	struct l2cap_conn_rsp rsp;
+	struct l2cap_chan *chan = NULL, *pchan;
+	int result, status = L2CAP_CS_NO_INFO;
+
+	u16 dcid = 0, scid = __le16_to_cpu(req->scid);
+	__le16 psm = req->psm;
+
+	BT_DBG("psm 0x%2.2x scid 0x%4.4x", __le16_to_cpu(psm), scid);
+
+	/* Check if we have socket listening on psm */
+	pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
+					 &conn->hcon->dst, ACL_LINK);
+	if (!pchan) {
+		result = L2CAP_CR_BAD_PSM;
+		goto sendresp;
+	}
+
+	mutex_lock(&conn->chan_lock);
+	l2cap_chan_lock(pchan);
+
+	/* Check if the ACL is secure enough (if not SDP) */
+	if (psm != cpu_to_le16(L2CAP_PSM_SDP) &&
+	    !hci_conn_check_link_mode(conn->hcon)) {
+		conn->disc_reason = HCI_ERROR_AUTH_FAILURE;
+		result = L2CAP_CR_SEC_BLOCK;
+		goto response;
+	}
+
+	result = L2CAP_CR_NO_MEM;
+
+	/* Check for valid dynamic CID range (as per Erratum 3253) */
+	if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_DYN_END) {
+		result = L2CAP_CR_INVALID_SCID;
+		goto response;
+	}
+
+	/* Check if we already have channel with that dcid */
+	if (__l2cap_get_chan_by_dcid(conn, scid)) {
+		result = L2CAP_CR_SCID_IN_USE;
+		goto response;
+	}
+
+	chan = pchan->ops->new_connection(pchan);
+	if (!chan)
+		goto response;
+
+	/* For certain devices (ex: HID mouse), support for authentication,
+	 * pairing and bonding is optional. For such devices, inorder to avoid
+	 * the ACL alive for too long after L2CAP disconnection, reset the ACL
+	 * disc_timeout back to HCI_DISCONN_TIMEOUT during L2CAP connect.
+	 */
+	conn->hcon->disc_timeout = HCI_DISCONN_TIMEOUT;
+
+	bacpy(&chan->src, &conn->hcon->src);
+	bacpy(&chan->dst, &conn->hcon->dst);
+	chan->src_type = bdaddr_src_type(conn->hcon);
+	chan->dst_type = bdaddr_dst_type(conn->hcon);
+	chan->psm  = psm;
+	chan->dcid = scid;
+	chan->local_amp_id = amp_id;
+
+	__l2cap_chan_add(conn, chan);
+
+	dcid = chan->scid;
+
+	__set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
+
+	chan->ident = cmd->ident;
+
+	if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) {
+		if (l2cap_chan_check_security(chan, false)) {
+			if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
+				l2cap_state_change(chan, BT_CONNECT2);
+				result = L2CAP_CR_PEND;
+				status = L2CAP_CS_AUTHOR_PEND;
+				chan->ops->defer(chan);
+			} else {
+				/* Force pending result for AMP controllers.
+				 * The connection will succeed after the
+				 * physical link is up.
+				 */
+				if (amp_id == AMP_ID_BREDR) {
+					l2cap_state_change(chan, BT_CONFIG);
+					result = L2CAP_CR_SUCCESS;
+				} else {
+					l2cap_state_change(chan, BT_CONNECT2);
+					result = L2CAP_CR_PEND;
+				}
+				status = L2CAP_CS_NO_INFO;
+			}
+		} else {
+			l2cap_state_change(chan, BT_CONNECT2);
+			result = L2CAP_CR_PEND;
+			status = L2CAP_CS_AUTHEN_PEND;
+		}
+	} else {
+		l2cap_state_change(chan, BT_CONNECT2);
+		result = L2CAP_CR_PEND;
+		status = L2CAP_CS_NO_INFO;
+	}
+
+response:
+	l2cap_chan_unlock(pchan);
+	mutex_unlock(&conn->chan_lock);
+	l2cap_chan_put(pchan);
+
+sendresp:
+	rsp.scid   = cpu_to_le16(scid);
+	rsp.dcid   = cpu_to_le16(dcid);
+	rsp.result = cpu_to_le16(result);
+	rsp.status = cpu_to_le16(status);
+	l2cap_send_cmd(conn, cmd->ident, rsp_code, sizeof(rsp), &rsp);
+
+	if (result == L2CAP_CR_PEND && status == L2CAP_CS_NO_INFO) {
+		struct l2cap_info_req info;
+		info.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
+
+		conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
+		conn->info_ident = l2cap_get_ident(conn);
+
+		schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
+
+		l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
+			       sizeof(info), &info);
+	}
+
+	if (chan && !test_bit(CONF_REQ_SENT, &chan->conf_state) &&
+	    result == L2CAP_CR_SUCCESS) {
+		u8 buf[128];
+		set_bit(CONF_REQ_SENT, &chan->conf_state);
+		l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
+			       l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
+		chan->num_conf_req++;
+	}
+
+	return chan;
+}
+
+static int l2cap_connect_req(struct l2cap_conn *conn,
+			     struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data)
+{
+	struct hci_dev *hdev = conn->hcon->hdev;
+	struct hci_conn *hcon = conn->hcon;
+
+	if (cmd_len < sizeof(struct l2cap_conn_req))
+		return -EPROTO;
+
+	hci_dev_lock(hdev);
+	if (hci_dev_test_flag(hdev, HCI_MGMT) &&
+	    !test_and_set_bit(HCI_CONN_MGMT_CONNECTED, &hcon->flags))
+		mgmt_device_connected(hdev, hcon, NULL, 0);
+	hci_dev_unlock(hdev);
+
+	l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP, 0);
+	return 0;
+}
+
+static int l2cap_connect_create_rsp(struct l2cap_conn *conn,
+				    struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				    u8 *data)
+{
+	struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data;
+	u16 scid, dcid, result, status;
+	struct l2cap_chan *chan;
+	u8 req[128];
+	int err;
+
+	if (cmd_len < sizeof(*rsp))
+		return -EPROTO;
+
+	scid   = __le16_to_cpu(rsp->scid);
+	dcid   = __le16_to_cpu(rsp->dcid);
+	result = __le16_to_cpu(rsp->result);
+	status = __le16_to_cpu(rsp->status);
+
+	if (result == L2CAP_CR_SUCCESS && (dcid < L2CAP_CID_DYN_START ||
+					   dcid > L2CAP_CID_DYN_END))
+		return -EPROTO;
+
+	BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x",
+	       dcid, scid, result, status);
+
+	mutex_lock(&conn->chan_lock);
+
+	if (scid) {
+		chan = __l2cap_get_chan_by_scid(conn, scid);
+		if (!chan) {
+			err = -EBADSLT;
+			goto unlock;
+		}
+	} else {
+		chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
+		if (!chan) {
+			err = -EBADSLT;
+			goto unlock;
+		}
+	}
+
+	chan = l2cap_chan_hold_unless_zero(chan);
+	if (!chan) {
+		err = -EBADSLT;
+		goto unlock;
+	}
+
+	err = 0;
+
+	l2cap_chan_lock(chan);
+
+	switch (result) {
+	case L2CAP_CR_SUCCESS:
+		if (__l2cap_get_chan_by_dcid(conn, dcid)) {
+			err = -EBADSLT;
+			break;
+		}
+
+		l2cap_state_change(chan, BT_CONFIG);
+		chan->ident = 0;
+		chan->dcid = dcid;
+		clear_bit(CONF_CONNECT_PEND, &chan->conf_state);
+
+		if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
+			break;
+
+		l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
+			       l2cap_build_conf_req(chan, req, sizeof(req)), req);
+		chan->num_conf_req++;
+		break;
+
+	case L2CAP_CR_PEND:
+		set_bit(CONF_CONNECT_PEND, &chan->conf_state);
+		break;
+
+	default:
+		l2cap_chan_del(chan, ECONNREFUSED);
+		break;
+	}
+
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+
+unlock:
+	mutex_unlock(&conn->chan_lock);
+
+	return err;
+}
+
+static inline void set_default_fcs(struct l2cap_chan *chan)
+{
+	/* FCS is enabled only in ERTM or streaming mode, if one or both
+	 * sides request it.
+	 */
+	if (chan->mode != L2CAP_MODE_ERTM && chan->mode != L2CAP_MODE_STREAMING)
+		chan->fcs = L2CAP_FCS_NONE;
+	else if (!test_bit(CONF_RECV_NO_FCS, &chan->conf_state))
+		chan->fcs = L2CAP_FCS_CRC16;
+}
+
+static void l2cap_send_efs_conf_rsp(struct l2cap_chan *chan, void *data,
+				    u8 ident, u16 flags)
+{
+	struct l2cap_conn *conn = chan->conn;
+
+	BT_DBG("conn %p chan %p ident %d flags 0x%4.4x", conn, chan, ident,
+	       flags);
+
+	clear_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
+	set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
+
+	l2cap_send_cmd(conn, ident, L2CAP_CONF_RSP,
+		       l2cap_build_conf_rsp(chan, data,
+					    L2CAP_CONF_SUCCESS, flags), data);
+}
+
+static void cmd_reject_invalid_cid(struct l2cap_conn *conn, u8 ident,
+				   u16 scid, u16 dcid)
+{
+	struct l2cap_cmd_rej_cid rej;
+
+	rej.reason = cpu_to_le16(L2CAP_REJ_INVALID_CID);
+	rej.scid = __cpu_to_le16(scid);
+	rej.dcid = __cpu_to_le16(dcid);
+
+	l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej);
+}
+
+static inline int l2cap_config_req(struct l2cap_conn *conn,
+				   struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				   u8 *data)
+{
+	struct l2cap_conf_req *req = (struct l2cap_conf_req *) data;
+	u16 dcid, flags;
+	u8 rsp[64];
+	struct l2cap_chan *chan;
+	int len, err = 0;
+
+	if (cmd_len < sizeof(*req))
+		return -EPROTO;
+
+	dcid  = __le16_to_cpu(req->dcid);
+	flags = __le16_to_cpu(req->flags);
+
+	BT_DBG("dcid 0x%4.4x flags 0x%2.2x", dcid, flags);
+
+	chan = l2cap_get_chan_by_scid(conn, dcid);
+	if (!chan) {
+		cmd_reject_invalid_cid(conn, cmd->ident, dcid, 0);
+		return 0;
+	}
+
+	if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2 &&
+	    chan->state != BT_CONNECTED) {
+		cmd_reject_invalid_cid(conn, cmd->ident, chan->scid,
+				       chan->dcid);
+		goto unlock;
+	}
+
+	/* Reject if config buffer is too small. */
+	len = cmd_len - sizeof(*req);
+	if (chan->conf_len + len > sizeof(chan->conf_req)) {
+		l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
+			       l2cap_build_conf_rsp(chan, rsp,
+			       L2CAP_CONF_REJECT, flags), rsp);
+		goto unlock;
+	}
+
+	/* Store config. */
+	memcpy(chan->conf_req + chan->conf_len, req->data, len);
+	chan->conf_len += len;
+
+	if (flags & L2CAP_CONF_FLAG_CONTINUATION) {
+		/* Incomplete config. Send empty response. */
+		l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
+			       l2cap_build_conf_rsp(chan, rsp,
+			       L2CAP_CONF_SUCCESS, flags), rsp);
+		goto unlock;
+	}
+
+	/* Complete config. */
+	len = l2cap_parse_conf_req(chan, rsp, sizeof(rsp));
+	if (len < 0) {
+		l2cap_send_disconn_req(chan, ECONNRESET);
+		goto unlock;
+	}
+
+	chan->ident = cmd->ident;
+	l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp);
+	if (chan->num_conf_rsp < L2CAP_CONF_MAX_CONF_RSP)
+		chan->num_conf_rsp++;
+
+	/* Reset config buffer. */
+	chan->conf_len = 0;
+
+	if (!test_bit(CONF_OUTPUT_DONE, &chan->conf_state))
+		goto unlock;
+
+	if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) {
+		set_default_fcs(chan);
+
+		if (chan->mode == L2CAP_MODE_ERTM ||
+		    chan->mode == L2CAP_MODE_STREAMING)
+			err = l2cap_ertm_init(chan);
+
+		if (err < 0)
+			l2cap_send_disconn_req(chan, -err);
+		else
+			l2cap_chan_ready(chan);
+
+		goto unlock;
+	}
+
+	if (!test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) {
+		u8 buf[64];
+		l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
+			       l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
+		chan->num_conf_req++;
+	}
+
+	/* Got Conf Rsp PENDING from remote side and assume we sent
+	   Conf Rsp PENDING in the code above */
+	if (test_bit(CONF_REM_CONF_PEND, &chan->conf_state) &&
+	    test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
+
+		/* check compatibility */
+
+		/* Send rsp for BR/EDR channel */
+		if (!chan->hs_hcon)
+			l2cap_send_efs_conf_rsp(chan, rsp, cmd->ident, flags);
+		else
+			chan->ident = cmd->ident;
+	}
+
+unlock:
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+	return err;
+}
+
+static inline int l2cap_config_rsp(struct l2cap_conn *conn,
+				   struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				   u8 *data)
+{
+	struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data;
+	u16 scid, flags, result;
+	struct l2cap_chan *chan;
+	int len = cmd_len - sizeof(*rsp);
+	int err = 0;
+
+	if (cmd_len < sizeof(*rsp))
+		return -EPROTO;
+
+	scid   = __le16_to_cpu(rsp->scid);
+	flags  = __le16_to_cpu(rsp->flags);
+	result = __le16_to_cpu(rsp->result);
+
+	BT_DBG("scid 0x%4.4x flags 0x%2.2x result 0x%2.2x len %d", scid, flags,
+	       result, len);
+
+	chan = l2cap_get_chan_by_scid(conn, scid);
+	if (!chan)
+		return 0;
+
+	switch (result) {
+	case L2CAP_CONF_SUCCESS:
+		l2cap_conf_rfc_get(chan, rsp->data, len);
+		clear_bit(CONF_REM_CONF_PEND, &chan->conf_state);
+		break;
+
+	case L2CAP_CONF_PENDING:
+		set_bit(CONF_REM_CONF_PEND, &chan->conf_state);
+
+		if (test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
+			char buf[64];
+
+			len = l2cap_parse_conf_rsp(chan, rsp->data, len,
+						   buf, sizeof(buf), &result);
+			if (len < 0) {
+				l2cap_send_disconn_req(chan, ECONNRESET);
+				goto done;
+			}
+
+			if (!chan->hs_hcon) {
+				l2cap_send_efs_conf_rsp(chan, buf, cmd->ident,
+							0);
+			} else {
+				if (l2cap_check_efs(chan)) {
+					amp_create_logical_link(chan);
+					chan->ident = cmd->ident;
+				}
+			}
+		}
+		goto done;
+
+	case L2CAP_CONF_UNKNOWN:
+	case L2CAP_CONF_UNACCEPT:
+		if (chan->num_conf_rsp <= L2CAP_CONF_MAX_CONF_RSP) {
+			char req[64];
+
+			if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) {
+				l2cap_send_disconn_req(chan, ECONNRESET);
+				goto done;
+			}
+
+			/* throw out any old stored conf requests */
+			result = L2CAP_CONF_SUCCESS;
+			len = l2cap_parse_conf_rsp(chan, rsp->data, len,
+						   req, sizeof(req), &result);
+			if (len < 0) {
+				l2cap_send_disconn_req(chan, ECONNRESET);
+				goto done;
+			}
+
+			l2cap_send_cmd(conn, l2cap_get_ident(conn),
+				       L2CAP_CONF_REQ, len, req);
+			chan->num_conf_req++;
+			if (result != L2CAP_CONF_SUCCESS)
+				goto done;
+			break;
+		}
+		fallthrough;
+
+	default:
+		l2cap_chan_set_err(chan, ECONNRESET);
+
+		__set_chan_timer(chan, L2CAP_DISC_REJ_TIMEOUT);
+		l2cap_send_disconn_req(chan, ECONNRESET);
+		goto done;
+	}
+
+	if (flags & L2CAP_CONF_FLAG_CONTINUATION)
+		goto done;
+
+	set_bit(CONF_INPUT_DONE, &chan->conf_state);
+
+	if (test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) {
+		set_default_fcs(chan);
+
+		if (chan->mode == L2CAP_MODE_ERTM ||
+		    chan->mode == L2CAP_MODE_STREAMING)
+			err = l2cap_ertm_init(chan);
+
+		if (err < 0)
+			l2cap_send_disconn_req(chan, -err);
+		else
+			l2cap_chan_ready(chan);
+	}
+
+done:
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+	return err;
+}
+
+static inline int l2cap_disconnect_req(struct l2cap_conn *conn,
+				       struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				       u8 *data)
+{
+	struct l2cap_disconn_req *req = (struct l2cap_disconn_req *) data;
+	struct l2cap_disconn_rsp rsp;
+	u16 dcid, scid;
+	struct l2cap_chan *chan;
+
+	if (cmd_len != sizeof(*req))
+		return -EPROTO;
+
+	scid = __le16_to_cpu(req->scid);
+	dcid = __le16_to_cpu(req->dcid);
+
+	BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid);
+
+	chan = l2cap_get_chan_by_scid(conn, dcid);
+	if (!chan) {
+		cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid);
+		return 0;
+	}
+
+	rsp.dcid = cpu_to_le16(chan->scid);
+	rsp.scid = cpu_to_le16(chan->dcid);
+	l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp);
+
+	chan->ops->set_shutdown(chan);
+
+	l2cap_chan_unlock(chan);
+	mutex_lock(&conn->chan_lock);
+	l2cap_chan_lock(chan);
+	l2cap_chan_del(chan, ECONNRESET);
+	mutex_unlock(&conn->chan_lock);
+
+	chan->ops->close(chan);
+
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+
+	return 0;
+}
+
+static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn,
+				       struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				       u8 *data)
+{
+	struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data;
+	u16 dcid, scid;
+	struct l2cap_chan *chan;
+
+	if (cmd_len != sizeof(*rsp))
+		return -EPROTO;
+
+	scid = __le16_to_cpu(rsp->scid);
+	dcid = __le16_to_cpu(rsp->dcid);
+
+	BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid);
+
+	chan = l2cap_get_chan_by_scid(conn, scid);
+	if (!chan) {
+		return 0;
+	}
+
+	if (chan->state != BT_DISCONN) {
+		l2cap_chan_unlock(chan);
+		l2cap_chan_put(chan);
+		return 0;
+	}
+
+	l2cap_chan_unlock(chan);
+	mutex_lock(&conn->chan_lock);
+	l2cap_chan_lock(chan);
+	l2cap_chan_del(chan, 0);
+	mutex_unlock(&conn->chan_lock);
+
+	chan->ops->close(chan);
+
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+
+	return 0;
+}
+
+static inline int l2cap_information_req(struct l2cap_conn *conn,
+					struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+					u8 *data)
+{
+	struct l2cap_info_req *req = (struct l2cap_info_req *) data;
+	u16 type;
+
+	if (cmd_len != sizeof(*req))
+		return -EPROTO;
+
+	type = __le16_to_cpu(req->type);
+
+	BT_DBG("type 0x%4.4x", type);
+
+	if (type == L2CAP_IT_FEAT_MASK) {
+		u8 buf[8];
+		u32 feat_mask = l2cap_feat_mask;
+		struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
+		rsp->type   = cpu_to_le16(L2CAP_IT_FEAT_MASK);
+		rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
+		if (!disable_ertm)
+			feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING
+				| L2CAP_FEAT_FCS;
+		if (conn->local_fixed_chan & L2CAP_FC_A2MP)
+			feat_mask |= L2CAP_FEAT_EXT_FLOW
+				| L2CAP_FEAT_EXT_WINDOW;
+
+		put_unaligned_le32(feat_mask, rsp->data);
+		l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
+			       buf);
+	} else if (type == L2CAP_IT_FIXED_CHAN) {
+		u8 buf[12];
+		struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
+
+		rsp->type   = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
+		rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
+		rsp->data[0] = conn->local_fixed_chan;
+		memset(rsp->data + 1, 0, 7);
+		l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
+			       buf);
+	} else {
+		struct l2cap_info_rsp rsp;
+		rsp.type   = cpu_to_le16(type);
+		rsp.result = cpu_to_le16(L2CAP_IR_NOTSUPP);
+		l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(rsp),
+			       &rsp);
+	}
+
+	return 0;
+}
+
+static inline int l2cap_information_rsp(struct l2cap_conn *conn,
+					struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+					u8 *data)
+{
+	struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data;
+	u16 type, result;
+
+	if (cmd_len < sizeof(*rsp))
+		return -EPROTO;
+
+	type   = __le16_to_cpu(rsp->type);
+	result = __le16_to_cpu(rsp->result);
+
+	BT_DBG("type 0x%4.4x result 0x%2.2x", type, result);
+
+	/* L2CAP Info req/rsp are unbound to channels, add extra checks */
+	if (cmd->ident != conn->info_ident ||
+	    conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
+		return 0;
+
+	cancel_delayed_work(&conn->info_timer);
+
+	if (result != L2CAP_IR_SUCCESS) {
+		conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
+		conn->info_ident = 0;
+
+		l2cap_conn_start(conn);
+
+		return 0;
+	}
+
+	switch (type) {
+	case L2CAP_IT_FEAT_MASK:
+		conn->feat_mask = get_unaligned_le32(rsp->data);
+
+		if (conn->feat_mask & L2CAP_FEAT_FIXED_CHAN) {
+			struct l2cap_info_req req;
+			req.type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
+
+			conn->info_ident = l2cap_get_ident(conn);
+
+			l2cap_send_cmd(conn, conn->info_ident,
+				       L2CAP_INFO_REQ, sizeof(req), &req);
+		} else {
+			conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
+			conn->info_ident = 0;
+
+			l2cap_conn_start(conn);
+		}
+		break;
+
+	case L2CAP_IT_FIXED_CHAN:
+		conn->remote_fixed_chan = rsp->data[0];
+		conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
+		conn->info_ident = 0;
+
+		l2cap_conn_start(conn);
+		break;
+	}
+
+	return 0;
+}
+
+static int l2cap_create_channel_req(struct l2cap_conn *conn,
+				    struct l2cap_cmd_hdr *cmd,
+				    u16 cmd_len, void *data)
+{
+	struct l2cap_create_chan_req *req = data;
+	struct l2cap_create_chan_rsp rsp;
+	struct l2cap_chan *chan;
+	struct hci_dev *hdev;
+	u16 psm, scid;
+
+	if (cmd_len != sizeof(*req))
+		return -EPROTO;
+
+	if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
+		return -EINVAL;
+
+	psm = le16_to_cpu(req->psm);
+	scid = le16_to_cpu(req->scid);
+
+	BT_DBG("psm 0x%2.2x, scid 0x%4.4x, amp_id %d", psm, scid, req->amp_id);
+
+	/* For controller id 0 make BR/EDR connection */
+	if (req->amp_id == AMP_ID_BREDR) {
+		l2cap_connect(conn, cmd, data, L2CAP_CREATE_CHAN_RSP,
+			      req->amp_id);
+		return 0;
+	}
+
+	/* Validate AMP controller id */
+	hdev = hci_dev_get(req->amp_id);
+	if (!hdev)
+		goto error;
+
+	if (hdev->dev_type != HCI_AMP || !test_bit(HCI_UP, &hdev->flags)) {
+		hci_dev_put(hdev);
+		goto error;
+	}
+
+	chan = l2cap_connect(conn, cmd, data, L2CAP_CREATE_CHAN_RSP,
+			     req->amp_id);
+	if (chan) {
+		struct amp_mgr *mgr = conn->hcon->amp_mgr;
+		struct hci_conn *hs_hcon;
+
+		hs_hcon = hci_conn_hash_lookup_ba(hdev, AMP_LINK,
+						  &conn->hcon->dst);
+		if (!hs_hcon) {
+			hci_dev_put(hdev);
+			cmd_reject_invalid_cid(conn, cmd->ident, chan->scid,
+					       chan->dcid);
+			return 0;
+		}
+
+		BT_DBG("mgr %p bredr_chan %p hs_hcon %p", mgr, chan, hs_hcon);
+
+		mgr->bredr_chan = chan;
+		chan->hs_hcon = hs_hcon;
+		chan->fcs = L2CAP_FCS_NONE;
+		conn->mtu = hdev->block_mtu;
+	}
+
+	hci_dev_put(hdev);
+
+	return 0;
+
+error:
+	rsp.dcid = 0;
+	rsp.scid = cpu_to_le16(scid);
+	rsp.result = cpu_to_le16(L2CAP_CR_BAD_AMP);
+	rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
+
+	l2cap_send_cmd(conn, cmd->ident, L2CAP_CREATE_CHAN_RSP,
+		       sizeof(rsp), &rsp);
+
+	return 0;
+}
+
+static void l2cap_send_move_chan_req(struct l2cap_chan *chan, u8 dest_amp_id)
+{
+	struct l2cap_move_chan_req req;
+	u8 ident;
+
+	BT_DBG("chan %p, dest_amp_id %d", chan, dest_amp_id);
+
+	ident = l2cap_get_ident(chan->conn);
+	chan->ident = ident;
+
+	req.icid = cpu_to_le16(chan->scid);
+	req.dest_amp_id = dest_amp_id;
+
+	l2cap_send_cmd(chan->conn, ident, L2CAP_MOVE_CHAN_REQ, sizeof(req),
+		       &req);
+
+	__set_chan_timer(chan, L2CAP_MOVE_TIMEOUT);
+}
+
+static void l2cap_send_move_chan_rsp(struct l2cap_chan *chan, u16 result)
+{
+	struct l2cap_move_chan_rsp rsp;
+
+	BT_DBG("chan %p, result 0x%4.4x", chan, result);
+
+	rsp.icid = cpu_to_le16(chan->dcid);
+	rsp.result = cpu_to_le16(result);
+
+	l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_RSP,
+		       sizeof(rsp), &rsp);
+}
+
+static void l2cap_send_move_chan_cfm(struct l2cap_chan *chan, u16 result)
+{
+	struct l2cap_move_chan_cfm cfm;
+
+	BT_DBG("chan %p, result 0x%4.4x", chan, result);
+
+	chan->ident = l2cap_get_ident(chan->conn);
+
+	cfm.icid = cpu_to_le16(chan->scid);
+	cfm.result = cpu_to_le16(result);
+
+	l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_CFM,
+		       sizeof(cfm), &cfm);
+
+	__set_chan_timer(chan, L2CAP_MOVE_TIMEOUT);
+}
+
+static void l2cap_send_move_chan_cfm_icid(struct l2cap_conn *conn, u16 icid)
+{
+	struct l2cap_move_chan_cfm cfm;
+
+	BT_DBG("conn %p, icid 0x%4.4x", conn, icid);
+
+	cfm.icid = cpu_to_le16(icid);
+	cfm.result = cpu_to_le16(L2CAP_MC_UNCONFIRMED);
+
+	l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_MOVE_CHAN_CFM,
+		       sizeof(cfm), &cfm);
+}
+
+static void l2cap_send_move_chan_cfm_rsp(struct l2cap_conn *conn, u8 ident,
+					 u16 icid)
+{
+	struct l2cap_move_chan_cfm_rsp rsp;
+
+	BT_DBG("icid 0x%4.4x", icid);
+
+	rsp.icid = cpu_to_le16(icid);
+	l2cap_send_cmd(conn, ident, L2CAP_MOVE_CHAN_CFM_RSP, sizeof(rsp), &rsp);
+}
+
+static void __release_logical_link(struct l2cap_chan *chan)
+{
+	chan->hs_hchan = NULL;
+	chan->hs_hcon = NULL;
+
+	/* Placeholder - release the logical link */
+}
+
+static void l2cap_logical_fail(struct l2cap_chan *chan)
+{
+	/* Logical link setup failed */
+	if (chan->state != BT_CONNECTED) {
+		/* Create channel failure, disconnect */
+		l2cap_send_disconn_req(chan, ECONNRESET);
+		return;
+	}
+
+	switch (chan->move_role) {
+	case L2CAP_MOVE_ROLE_RESPONDER:
+		l2cap_move_done(chan);
+		l2cap_send_move_chan_rsp(chan, L2CAP_MR_NOT_SUPP);
+		break;
+	case L2CAP_MOVE_ROLE_INITIATOR:
+		if (chan->move_state == L2CAP_MOVE_WAIT_LOGICAL_COMP ||
+		    chan->move_state == L2CAP_MOVE_WAIT_LOGICAL_CFM) {
+			/* Remote has only sent pending or
+			 * success responses, clean up
+			 */
+			l2cap_move_done(chan);
+		}
+
+		/* Other amp move states imply that the move
+		 * has already aborted
+		 */
+		l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
+		break;
+	}
+}
+
+static void l2cap_logical_finish_create(struct l2cap_chan *chan,
+					struct hci_chan *hchan)
+{
+	struct l2cap_conf_rsp rsp;
+
+	chan->hs_hchan = hchan;
+	chan->hs_hcon->l2cap_data = chan->conn;
+
+	l2cap_send_efs_conf_rsp(chan, &rsp, chan->ident, 0);
+
+	if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) {
+		int err;
+
+		set_default_fcs(chan);
+
+		err = l2cap_ertm_init(chan);
+		if (err < 0)
+			l2cap_send_disconn_req(chan, -err);
+		else
+			l2cap_chan_ready(chan);
+	}
+}
+
+static void l2cap_logical_finish_move(struct l2cap_chan *chan,
+				      struct hci_chan *hchan)
+{
+	chan->hs_hcon = hchan->conn;
+	chan->hs_hcon->l2cap_data = chan->conn;
+
+	BT_DBG("move_state %d", chan->move_state);
+
+	switch (chan->move_state) {
+	case L2CAP_MOVE_WAIT_LOGICAL_COMP:
+		/* Move confirm will be sent after a success
+		 * response is received
+		 */
+		chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
+		break;
+	case L2CAP_MOVE_WAIT_LOGICAL_CFM:
+		if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
+			chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
+		} else if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) {
+			chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP;
+			l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
+		} else if (chan->move_role == L2CAP_MOVE_ROLE_RESPONDER) {
+			chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
+			l2cap_send_move_chan_rsp(chan, L2CAP_MR_SUCCESS);
+		}
+		break;
+	default:
+		/* Move was not in expected state, free the channel */
+		__release_logical_link(chan);
+
+		chan->move_state = L2CAP_MOVE_STABLE;
+	}
+}
+
+/* Call with chan locked */
+void l2cap_logical_cfm(struct l2cap_chan *chan, struct hci_chan *hchan,
+		       u8 status)
+{
+	BT_DBG("chan %p, hchan %p, status %d", chan, hchan, status);
+
+	if (status) {
+		l2cap_logical_fail(chan);
+		__release_logical_link(chan);
+		return;
+	}
+
+	if (chan->state != BT_CONNECTED) {
+		/* Ignore logical link if channel is on BR/EDR */
+		if (chan->local_amp_id != AMP_ID_BREDR)
+			l2cap_logical_finish_create(chan, hchan);
+	} else {
+		l2cap_logical_finish_move(chan, hchan);
+	}
+}
+
+void l2cap_move_start(struct l2cap_chan *chan)
+{
+	BT_DBG("chan %p", chan);
+
+	if (chan->local_amp_id == AMP_ID_BREDR) {
+		if (chan->chan_policy != BT_CHANNEL_POLICY_AMP_PREFERRED)
+			return;
+		chan->move_role = L2CAP_MOVE_ROLE_INITIATOR;
+		chan->move_state = L2CAP_MOVE_WAIT_PREPARE;
+		/* Placeholder - start physical link setup */
+	} else {
+		chan->move_role = L2CAP_MOVE_ROLE_INITIATOR;
+		chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
+		chan->move_id = 0;
+		l2cap_move_setup(chan);
+		l2cap_send_move_chan_req(chan, 0);
+	}
+}
+
+static void l2cap_do_create(struct l2cap_chan *chan, int result,
+			    u8 local_amp_id, u8 remote_amp_id)
+{
+	BT_DBG("chan %p state %s %u -> %u", chan, state_to_string(chan->state),
+	       local_amp_id, remote_amp_id);
+
+	chan->fcs = L2CAP_FCS_NONE;
+
+	/* Outgoing channel on AMP */
+	if (chan->state == BT_CONNECT) {
+		if (result == L2CAP_CR_SUCCESS) {
+			chan->local_amp_id = local_amp_id;
+			l2cap_send_create_chan_req(chan, remote_amp_id);
+		} else {
+			/* Revert to BR/EDR connect */
+			l2cap_send_conn_req(chan);
+		}
+
+		return;
+	}
+
+	/* Incoming channel on AMP */
+	if (__l2cap_no_conn_pending(chan)) {
+		struct l2cap_conn_rsp rsp;
+		char buf[128];
+		rsp.scid = cpu_to_le16(chan->dcid);
+		rsp.dcid = cpu_to_le16(chan->scid);
+
+		if (result == L2CAP_CR_SUCCESS) {
+			/* Send successful response */
+			rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
+			rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
+		} else {
+			/* Send negative response */
+			rsp.result = cpu_to_le16(L2CAP_CR_NO_MEM);
+			rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
+		}
+
+		l2cap_send_cmd(chan->conn, chan->ident, L2CAP_CREATE_CHAN_RSP,
+			       sizeof(rsp), &rsp);
+
+		if (result == L2CAP_CR_SUCCESS) {
+			l2cap_state_change(chan, BT_CONFIG);
+			set_bit(CONF_REQ_SENT, &chan->conf_state);
+			l2cap_send_cmd(chan->conn, l2cap_get_ident(chan->conn),
+				       L2CAP_CONF_REQ,
+				       l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
+			chan->num_conf_req++;
+		}
+	}
+}
+
+static void l2cap_do_move_initiate(struct l2cap_chan *chan, u8 local_amp_id,
+				   u8 remote_amp_id)
+{
+	l2cap_move_setup(chan);
+	chan->move_id = local_amp_id;
+	chan->move_state = L2CAP_MOVE_WAIT_RSP;
+
+	l2cap_send_move_chan_req(chan, remote_amp_id);
+}
+
+static void l2cap_do_move_respond(struct l2cap_chan *chan, int result)
+{
+	struct hci_chan *hchan = NULL;
+
+	/* Placeholder - get hci_chan for logical link */
+
+	if (hchan) {
+		if (hchan->state == BT_CONNECTED) {
+			/* Logical link is ready to go */
+			chan->hs_hcon = hchan->conn;
+			chan->hs_hcon->l2cap_data = chan->conn;
+			chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
+			l2cap_send_move_chan_rsp(chan, L2CAP_MR_SUCCESS);
+
+			l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS);
+		} else {
+			/* Wait for logical link to be ready */
+			chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
+		}
+	} else {
+		/* Logical link not available */
+		l2cap_send_move_chan_rsp(chan, L2CAP_MR_NOT_ALLOWED);
+	}
+}
+
+static void l2cap_do_move_cancel(struct l2cap_chan *chan, int result)
+{
+	if (chan->move_role == L2CAP_MOVE_ROLE_RESPONDER) {
+		u8 rsp_result;
+		if (result == -EINVAL)
+			rsp_result = L2CAP_MR_BAD_ID;
+		else
+			rsp_result = L2CAP_MR_NOT_ALLOWED;
+
+		l2cap_send_move_chan_rsp(chan, rsp_result);
+	}
+
+	chan->move_role = L2CAP_MOVE_ROLE_NONE;
+	chan->move_state = L2CAP_MOVE_STABLE;
+
+	/* Restart data transmission */
+	l2cap_ertm_send(chan);
+}
+
+/* Invoke with locked chan */
+void __l2cap_physical_cfm(struct l2cap_chan *chan, int result)
+{
+	u8 local_amp_id = chan->local_amp_id;
+	u8 remote_amp_id = chan->remote_amp_id;
+
+	BT_DBG("chan %p, result %d, local_amp_id %d, remote_amp_id %d",
+	       chan, result, local_amp_id, remote_amp_id);
+
+	if (chan->state == BT_DISCONN || chan->state == BT_CLOSED)
+		return;
+
+	if (chan->state != BT_CONNECTED) {
+		l2cap_do_create(chan, result, local_amp_id, remote_amp_id);
+	} else if (result != L2CAP_MR_SUCCESS) {
+		l2cap_do_move_cancel(chan, result);
+	} else {
+		switch (chan->move_role) {
+		case L2CAP_MOVE_ROLE_INITIATOR:
+			l2cap_do_move_initiate(chan, local_amp_id,
+					       remote_amp_id);
+			break;
+		case L2CAP_MOVE_ROLE_RESPONDER:
+			l2cap_do_move_respond(chan, result);
+			break;
+		default:
+			l2cap_do_move_cancel(chan, result);
+			break;
+		}
+	}
+}
+
+static inline int l2cap_move_channel_req(struct l2cap_conn *conn,
+					 struct l2cap_cmd_hdr *cmd,
+					 u16 cmd_len, void *data)
+{
+	struct l2cap_move_chan_req *req = data;
+	struct l2cap_move_chan_rsp rsp;
+	struct l2cap_chan *chan;
+	u16 icid = 0;
+	u16 result = L2CAP_MR_NOT_ALLOWED;
+
+	if (cmd_len != sizeof(*req))
+		return -EPROTO;
+
+	icid = le16_to_cpu(req->icid);
+
+	BT_DBG("icid 0x%4.4x, dest_amp_id %d", icid, req->dest_amp_id);
+
+	if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
+		return -EINVAL;
+
+	chan = l2cap_get_chan_by_dcid(conn, icid);
+	if (!chan) {
+		rsp.icid = cpu_to_le16(icid);
+		rsp.result = cpu_to_le16(L2CAP_MR_NOT_ALLOWED);
+		l2cap_send_cmd(conn, cmd->ident, L2CAP_MOVE_CHAN_RSP,
+			       sizeof(rsp), &rsp);
+		return 0;
+	}
+
+	chan->ident = cmd->ident;
+
+	if (chan->scid < L2CAP_CID_DYN_START ||
+	    chan->chan_policy == BT_CHANNEL_POLICY_BREDR_ONLY ||
+	    (chan->mode != L2CAP_MODE_ERTM &&
+	     chan->mode != L2CAP_MODE_STREAMING)) {
+		result = L2CAP_MR_NOT_ALLOWED;
+		goto send_move_response;
+	}
+
+	if (chan->local_amp_id == req->dest_amp_id) {
+		result = L2CAP_MR_SAME_ID;
+		goto send_move_response;
+	}
+
+	if (req->dest_amp_id != AMP_ID_BREDR) {
+		struct hci_dev *hdev;
+		hdev = hci_dev_get(req->dest_amp_id);
+		if (!hdev || hdev->dev_type != HCI_AMP ||
+		    !test_bit(HCI_UP, &hdev->flags)) {
+			if (hdev)
+				hci_dev_put(hdev);
+
+			result = L2CAP_MR_BAD_ID;
+			goto send_move_response;
+		}
+		hci_dev_put(hdev);
+	}
+
+	/* Detect a move collision.  Only send a collision response
+	 * if this side has "lost", otherwise proceed with the move.
+	 * The winner has the larger bd_addr.
+	 */
+	if ((__chan_is_moving(chan) ||
+	     chan->move_role != L2CAP_MOVE_ROLE_NONE) &&
+	    bacmp(&conn->hcon->src, &conn->hcon->dst) > 0) {
+		result = L2CAP_MR_COLLISION;
+		goto send_move_response;
+	}
+
+	chan->move_role = L2CAP_MOVE_ROLE_RESPONDER;
+	l2cap_move_setup(chan);
+	chan->move_id = req->dest_amp_id;
+
+	if (req->dest_amp_id == AMP_ID_BREDR) {
+		/* Moving to BR/EDR */
+		if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
+			chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
+			result = L2CAP_MR_PEND;
+		} else {
+			chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
+			result = L2CAP_MR_SUCCESS;
+		}
+	} else {
+		chan->move_state = L2CAP_MOVE_WAIT_PREPARE;
+		/* Placeholder - uncomment when amp functions are available */
+		/*amp_accept_physical(chan, req->dest_amp_id);*/
+		result = L2CAP_MR_PEND;
+	}
+
+send_move_response:
+	l2cap_send_move_chan_rsp(chan, result);
+
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+
+	return 0;
+}
+
+static void l2cap_move_continue(struct l2cap_conn *conn, u16 icid, u16 result)
+{
+	struct l2cap_chan *chan;
+	struct hci_chan *hchan = NULL;
+
+	chan = l2cap_get_chan_by_scid(conn, icid);
+	if (!chan) {
+		l2cap_send_move_chan_cfm_icid(conn, icid);
+		return;
+	}
+
+	__clear_chan_timer(chan);
+	if (result == L2CAP_MR_PEND)
+		__set_chan_timer(chan, L2CAP_MOVE_ERTX_TIMEOUT);
+
+	switch (chan->move_state) {
+	case L2CAP_MOVE_WAIT_LOGICAL_COMP:
+		/* Move confirm will be sent when logical link
+		 * is complete.
+		 */
+		chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
+		break;
+	case L2CAP_MOVE_WAIT_RSP_SUCCESS:
+		if (result == L2CAP_MR_PEND) {
+			break;
+		} else if (test_bit(CONN_LOCAL_BUSY,
+				    &chan->conn_state)) {
+			chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
+		} else {
+			/* Logical link is up or moving to BR/EDR,
+			 * proceed with move
+			 */
+			chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP;
+			l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
+		}
+		break;
+	case L2CAP_MOVE_WAIT_RSP:
+		/* Moving to AMP */
+		if (result == L2CAP_MR_SUCCESS) {
+			/* Remote is ready, send confirm immediately
+			 * after logical link is ready
+			 */
+			chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
+		} else {
+			/* Both logical link and move success
+			 * are required to confirm
+			 */
+			chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_COMP;
+		}
+
+		/* Placeholder - get hci_chan for logical link */
+		if (!hchan) {
+			/* Logical link not available */
+			l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
+			break;
+		}
+
+		/* If the logical link is not yet connected, do not
+		 * send confirmation.
+		 */
+		if (hchan->state != BT_CONNECTED)
+			break;
+
+		/* Logical link is already ready to go */
+
+		chan->hs_hcon = hchan->conn;
+		chan->hs_hcon->l2cap_data = chan->conn;
+
+		if (result == L2CAP_MR_SUCCESS) {
+			/* Can confirm now */
+			l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
+		} else {
+			/* Now only need move success
+			 * to confirm
+			 */
+			chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
+		}
+
+		l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS);
+		break;
+	default:
+		/* Any other amp move state means the move failed. */
+		chan->move_id = chan->local_amp_id;
+		l2cap_move_done(chan);
+		l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
+	}
+
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+}
+
+static void l2cap_move_fail(struct l2cap_conn *conn, u8 ident, u16 icid,
+			    u16 result)
+{
+	struct l2cap_chan *chan;
+
+	chan = l2cap_get_chan_by_ident(conn, ident);
+	if (!chan) {
+		/* Could not locate channel, icid is best guess */
+		l2cap_send_move_chan_cfm_icid(conn, icid);
+		return;
+	}
+
+	__clear_chan_timer(chan);
+
+	if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) {
+		if (result == L2CAP_MR_COLLISION) {
+			chan->move_role = L2CAP_MOVE_ROLE_RESPONDER;
+		} else {
+			/* Cleanup - cancel move */
+			chan->move_id = chan->local_amp_id;
+			l2cap_move_done(chan);
+		}
+	}
+
+	l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
+
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+}
+
+static int l2cap_move_channel_rsp(struct l2cap_conn *conn,
+				  struct l2cap_cmd_hdr *cmd,
+				  u16 cmd_len, void *data)
+{
+	struct l2cap_move_chan_rsp *rsp = data;
+	u16 icid, result;
+
+	if (cmd_len != sizeof(*rsp))
+		return -EPROTO;
+
+	icid = le16_to_cpu(rsp->icid);
+	result = le16_to_cpu(rsp->result);
+
+	BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result);
+
+	if (result == L2CAP_MR_SUCCESS || result == L2CAP_MR_PEND)
+		l2cap_move_continue(conn, icid, result);
+	else
+		l2cap_move_fail(conn, cmd->ident, icid, result);
+
+	return 0;
+}
+
+static int l2cap_move_channel_confirm(struct l2cap_conn *conn,
+				      struct l2cap_cmd_hdr *cmd,
+				      u16 cmd_len, void *data)
+{
+	struct l2cap_move_chan_cfm *cfm = data;
+	struct l2cap_chan *chan;
+	u16 icid, result;
+
+	if (cmd_len != sizeof(*cfm))
+		return -EPROTO;
+
+	icid = le16_to_cpu(cfm->icid);
+	result = le16_to_cpu(cfm->result);
+
+	BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result);
+
+	chan = l2cap_get_chan_by_dcid(conn, icid);
+	if (!chan) {
+		/* Spec requires a response even if the icid was not found */
+		l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid);
+		return 0;
+	}
+
+	if (chan->move_state == L2CAP_MOVE_WAIT_CONFIRM) {
+		if (result == L2CAP_MC_CONFIRMED) {
+			chan->local_amp_id = chan->move_id;
+			if (chan->local_amp_id == AMP_ID_BREDR)
+				__release_logical_link(chan);
+		} else {
+			chan->move_id = chan->local_amp_id;
+		}
+
+		l2cap_move_done(chan);
+	}
+
+	l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid);
+
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+
+	return 0;
+}
+
+static inline int l2cap_move_channel_confirm_rsp(struct l2cap_conn *conn,
+						 struct l2cap_cmd_hdr *cmd,
+						 u16 cmd_len, void *data)
+{
+	struct l2cap_move_chan_cfm_rsp *rsp = data;
+	struct l2cap_chan *chan;
+	u16 icid;
+
+	if (cmd_len != sizeof(*rsp))
+		return -EPROTO;
+
+	icid = le16_to_cpu(rsp->icid);
+
+	BT_DBG("icid 0x%4.4x", icid);
+
+	chan = l2cap_get_chan_by_scid(conn, icid);
+	if (!chan)
+		return 0;
+
+	__clear_chan_timer(chan);
+
+	if (chan->move_state == L2CAP_MOVE_WAIT_CONFIRM_RSP) {
+		chan->local_amp_id = chan->move_id;
+
+		if (chan->local_amp_id == AMP_ID_BREDR && chan->hs_hchan)
+			__release_logical_link(chan);
+
+		l2cap_move_done(chan);
+	}
+
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+
+	return 0;
+}
+
+static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
+					      struct l2cap_cmd_hdr *cmd,
+					      u16 cmd_len, u8 *data)
+{
+	struct hci_conn *hcon = conn->hcon;
+	struct l2cap_conn_param_update_req *req;
+	struct l2cap_conn_param_update_rsp rsp;
+	u16 min, max, latency, to_multiplier;
+	int err;
+
+	if (hcon->role != HCI_ROLE_MASTER)
+		return -EINVAL;
+
+	if (cmd_len != sizeof(struct l2cap_conn_param_update_req))
+		return -EPROTO;
+
+	req = (struct l2cap_conn_param_update_req *) data;
+	min		= __le16_to_cpu(req->min);
+	max		= __le16_to_cpu(req->max);
+	latency		= __le16_to_cpu(req->latency);
+	to_multiplier	= __le16_to_cpu(req->to_multiplier);
+
+	BT_DBG("min 0x%4.4x max 0x%4.4x latency: 0x%4.4x Timeout: 0x%4.4x",
+	       min, max, latency, to_multiplier);
+
+	memset(&rsp, 0, sizeof(rsp));
+
+	err = hci_check_conn_params(min, max, latency, to_multiplier);
+	if (err)
+		rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED);
+	else
+		rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_ACCEPTED);
+
+	l2cap_send_cmd(conn, cmd->ident, L2CAP_CONN_PARAM_UPDATE_RSP,
+		       sizeof(rsp), &rsp);
+
+	if (!err) {
+		u8 store_hint;
+
+		store_hint = hci_le_conn_update(hcon, min, max, latency,
+						to_multiplier);
+		mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type,
+				    store_hint, min, max, latency,
+				    to_multiplier);
+
+	}
+
+	return 0;
+}
+
+static int l2cap_le_connect_rsp(struct l2cap_conn *conn,
+				struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				u8 *data)
+{
+	struct l2cap_le_conn_rsp *rsp = (struct l2cap_le_conn_rsp *) data;
+	struct hci_conn *hcon = conn->hcon;
+	u16 dcid, mtu, mps, credits, result;
+	struct l2cap_chan *chan;
+	int err, sec_level;
+
+	if (cmd_len < sizeof(*rsp))
+		return -EPROTO;
+
+	dcid    = __le16_to_cpu(rsp->dcid);
+	mtu     = __le16_to_cpu(rsp->mtu);
+	mps     = __le16_to_cpu(rsp->mps);
+	credits = __le16_to_cpu(rsp->credits);
+	result  = __le16_to_cpu(rsp->result);
+
+	if (result == L2CAP_CR_LE_SUCCESS && (mtu < 23 || mps < 23 ||
+					   dcid < L2CAP_CID_DYN_START ||
+					   dcid > L2CAP_CID_LE_DYN_END))
+		return -EPROTO;
+
+	BT_DBG("dcid 0x%4.4x mtu %u mps %u credits %u result 0x%2.2x",
+	       dcid, mtu, mps, credits, result);
+
+	mutex_lock(&conn->chan_lock);
+
+	chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
+	if (!chan) {
+		err = -EBADSLT;
+		goto unlock;
+	}
+
+	err = 0;
+
+	l2cap_chan_lock(chan);
+
+	switch (result) {
+	case L2CAP_CR_LE_SUCCESS:
+		if (__l2cap_get_chan_by_dcid(conn, dcid)) {
+			err = -EBADSLT;
+			break;
+		}
+
+		chan->ident = 0;
+		chan->dcid = dcid;
+		chan->omtu = mtu;
+		chan->remote_mps = mps;
+		chan->tx_credits = credits;
+		l2cap_chan_ready(chan);
+		break;
+
+	case L2CAP_CR_LE_AUTHENTICATION:
+	case L2CAP_CR_LE_ENCRYPTION:
+		/* If we already have MITM protection we can't do
+		 * anything.
+		 */
+		if (hcon->sec_level > BT_SECURITY_MEDIUM) {
+			l2cap_chan_del(chan, ECONNREFUSED);
+			break;
+		}
+
+		sec_level = hcon->sec_level + 1;
+		if (chan->sec_level < sec_level)
+			chan->sec_level = sec_level;
+
+		/* We'll need to send a new Connect Request */
+		clear_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags);
+
+		smp_conn_security(hcon, chan->sec_level);
+		break;
+
+	default:
+		l2cap_chan_del(chan, ECONNREFUSED);
+		break;
+	}
+
+	l2cap_chan_unlock(chan);
+
+unlock:
+	mutex_unlock(&conn->chan_lock);
+
+	return err;
+}
+
+static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
+				      struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				      u8 *data)
+{
+	int err = 0;
+
+	switch (cmd->code) {
+	case L2CAP_COMMAND_REJ:
+		l2cap_command_rej(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_CONN_REQ:
+		err = l2cap_connect_req(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_CONN_RSP:
+	case L2CAP_CREATE_CHAN_RSP:
+		l2cap_connect_create_rsp(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_CONF_REQ:
+		err = l2cap_config_req(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_CONF_RSP:
+		l2cap_config_rsp(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_DISCONN_REQ:
+		err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_DISCONN_RSP:
+		l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_ECHO_REQ:
+		l2cap_send_cmd(conn, cmd->ident, L2CAP_ECHO_RSP, cmd_len, data);
+		break;
+
+	case L2CAP_ECHO_RSP:
+		break;
+
+	case L2CAP_INFO_REQ:
+		err = l2cap_information_req(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_INFO_RSP:
+		l2cap_information_rsp(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_CREATE_CHAN_REQ:
+		err = l2cap_create_channel_req(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_MOVE_CHAN_REQ:
+		err = l2cap_move_channel_req(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_MOVE_CHAN_RSP:
+		l2cap_move_channel_rsp(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_MOVE_CHAN_CFM:
+		err = l2cap_move_channel_confirm(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_MOVE_CHAN_CFM_RSP:
+		l2cap_move_channel_confirm_rsp(conn, cmd, cmd_len, data);
+		break;
+
+	default:
+		BT_ERR("Unknown BR/EDR signaling command 0x%2.2x", cmd->code);
+		err = -EINVAL;
+		break;
+	}
+
+	return err;
+}
+
+static int l2cap_le_connect_req(struct l2cap_conn *conn,
+				struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				u8 *data)
+{
+	struct l2cap_le_conn_req *req = (struct l2cap_le_conn_req *) data;
+	struct l2cap_le_conn_rsp rsp;
+	struct l2cap_chan *chan, *pchan;
+	u16 dcid, scid, credits, mtu, mps;
+	__le16 psm;
+	u8 result;
+
+	if (cmd_len != sizeof(*req))
+		return -EPROTO;
+
+	scid = __le16_to_cpu(req->scid);
+	mtu  = __le16_to_cpu(req->mtu);
+	mps  = __le16_to_cpu(req->mps);
+	psm  = req->psm;
+	dcid = 0;
+	credits = 0;
+
+	if (mtu < 23 || mps < 23)
+		return -EPROTO;
+
+	BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
+	       scid, mtu, mps);
+
+	/* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
+	 * page 1059:
+	 *
+	 * Valid range: 0x0001-0x00ff
+	 *
+	 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
+	 */
+	if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
+		result = L2CAP_CR_LE_BAD_PSM;
+		chan = NULL;
+		goto response;
+	}
+
+	/* Check if we have socket listening on psm */
+	pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
+					 &conn->hcon->dst, LE_LINK);
+	if (!pchan) {
+		result = L2CAP_CR_LE_BAD_PSM;
+		chan = NULL;
+		goto response;
+	}
+
+	mutex_lock(&conn->chan_lock);
+	l2cap_chan_lock(pchan);
+
+	if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
+				     SMP_ALLOW_STK)) {
+		result = L2CAP_CR_LE_AUTHENTICATION;
+		chan = NULL;
+		goto response_unlock;
+	}
+
+	/* Check for valid dynamic CID range */
+	if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) {
+		result = L2CAP_CR_LE_INVALID_SCID;
+		chan = NULL;
+		goto response_unlock;
+	}
+
+	/* Check if we already have channel with that dcid */
+	if (__l2cap_get_chan_by_dcid(conn, scid)) {
+		result = L2CAP_CR_LE_SCID_IN_USE;
+		chan = NULL;
+		goto response_unlock;
+	}
+
+	chan = pchan->ops->new_connection(pchan);
+	if (!chan) {
+		result = L2CAP_CR_LE_NO_MEM;
+		goto response_unlock;
+	}
+
+	bacpy(&chan->src, &conn->hcon->src);
+	bacpy(&chan->dst, &conn->hcon->dst);
+	chan->src_type = bdaddr_src_type(conn->hcon);
+	chan->dst_type = bdaddr_dst_type(conn->hcon);
+	chan->psm  = psm;
+	chan->dcid = scid;
+	chan->omtu = mtu;
+	chan->remote_mps = mps;
+
+	__l2cap_chan_add(conn, chan);
+
+	l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits));
+
+	dcid = chan->scid;
+	credits = chan->rx_credits;
+
+	__set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
+
+	chan->ident = cmd->ident;
+
+	if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
+		l2cap_state_change(chan, BT_CONNECT2);
+		/* The following result value is actually not defined
+		 * for LE CoC but we use it to let the function know
+		 * that it should bail out after doing its cleanup
+		 * instead of sending a response.
+		 */
+		result = L2CAP_CR_PEND;
+		chan->ops->defer(chan);
+	} else {
+		l2cap_chan_ready(chan);
+		result = L2CAP_CR_LE_SUCCESS;
+	}
+
+response_unlock:
+	l2cap_chan_unlock(pchan);
+	mutex_unlock(&conn->chan_lock);
+	l2cap_chan_put(pchan);
+
+	if (result == L2CAP_CR_PEND)
+		return 0;
+
+response:
+	if (chan) {
+		rsp.mtu = cpu_to_le16(chan->imtu);
+		rsp.mps = cpu_to_le16(chan->mps);
+	} else {
+		rsp.mtu = 0;
+		rsp.mps = 0;
+	}
+
+	rsp.dcid    = cpu_to_le16(dcid);
+	rsp.credits = cpu_to_le16(credits);
+	rsp.result  = cpu_to_le16(result);
+
+	l2cap_send_cmd(conn, cmd->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), &rsp);
+
+	return 0;
+}
+
+static inline int l2cap_le_credits(struct l2cap_conn *conn,
+				   struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				   u8 *data)
+{
+	struct l2cap_le_credits *pkt;
+	struct l2cap_chan *chan;
+	u16 cid, credits, max_credits;
+
+	if (cmd_len != sizeof(*pkt))
+		return -EPROTO;
+
+	pkt = (struct l2cap_le_credits *) data;
+	cid	= __le16_to_cpu(pkt->cid);
+	credits	= __le16_to_cpu(pkt->credits);
+
+	BT_DBG("cid 0x%4.4x credits 0x%4.4x", cid, credits);
+
+	chan = l2cap_get_chan_by_dcid(conn, cid);
+	if (!chan)
+		return -EBADSLT;
+
+	max_credits = LE_FLOWCTL_MAX_CREDITS - chan->tx_credits;
+	if (credits > max_credits) {
+		BT_ERR("LE credits overflow");
+		l2cap_send_disconn_req(chan, ECONNRESET);
+
+		/* Return 0 so that we don't trigger an unnecessary
+		 * command reject packet.
+		 */
+		goto unlock;
+	}
+
+	chan->tx_credits += credits;
+
+	/* Resume sending */
+	l2cap_le_flowctl_send(chan);
+
+	if (chan->tx_credits)
+		chan->ops->resume(chan);
+
+unlock:
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+
+	return 0;
+}
+
+static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn,
+				       struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				       u8 *data)
+{
+	struct l2cap_ecred_conn_req *req = (void *) data;
+	struct {
+		struct l2cap_ecred_conn_rsp rsp;
+		__le16 dcid[L2CAP_ECRED_MAX_CID];
+	} __packed pdu;
+	struct l2cap_chan *chan, *pchan;
+	u16 mtu, mps;
+	__le16 psm;
+	u8 result, len = 0;
+	int i, num_scid;
+	bool defer = false;
+
+	if (!enable_ecred)
+		return -EINVAL;
+
+	if (cmd_len < sizeof(*req) || (cmd_len - sizeof(*req)) % sizeof(u16)) {
+		result = L2CAP_CR_LE_INVALID_PARAMS;
+		goto response;
+	}
+
+	cmd_len -= sizeof(*req);
+	num_scid = cmd_len / sizeof(u16);
+
+	if (num_scid > ARRAY_SIZE(pdu.dcid)) {
+		result = L2CAP_CR_LE_INVALID_PARAMS;
+		goto response;
+	}
+
+	mtu  = __le16_to_cpu(req->mtu);
+	mps  = __le16_to_cpu(req->mps);
+
+	if (mtu < L2CAP_ECRED_MIN_MTU || mps < L2CAP_ECRED_MIN_MPS) {
+		result = L2CAP_CR_LE_UNACCEPT_PARAMS;
+		goto response;
+	}
+
+	psm  = req->psm;
+
+	/* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
+	 * page 1059:
+	 *
+	 * Valid range: 0x0001-0x00ff
+	 *
+	 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
+	 */
+	if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
+		result = L2CAP_CR_LE_BAD_PSM;
+		goto response;
+	}
+
+	BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps);
+
+	memset(&pdu, 0, sizeof(pdu));
+
+	/* Check if we have socket listening on psm */
+	pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
+					 &conn->hcon->dst, LE_LINK);
+	if (!pchan) {
+		result = L2CAP_CR_LE_BAD_PSM;
+		goto response;
+	}
+
+	mutex_lock(&conn->chan_lock);
+	l2cap_chan_lock(pchan);
+
+	if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
+				     SMP_ALLOW_STK)) {
+		result = L2CAP_CR_LE_AUTHENTICATION;
+		goto unlock;
+	}
+
+	result = L2CAP_CR_LE_SUCCESS;
+
+	for (i = 0; i < num_scid; i++) {
+		u16 scid = __le16_to_cpu(req->scid[i]);
+
+		BT_DBG("scid[%d] 0x%4.4x", i, scid);
+
+		pdu.dcid[i] = 0x0000;
+		len += sizeof(*pdu.dcid);
+
+		/* Check for valid dynamic CID range */
+		if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) {
+			result = L2CAP_CR_LE_INVALID_SCID;
+			continue;
+		}
+
+		/* Check if we already have channel with that dcid */
+		if (__l2cap_get_chan_by_dcid(conn, scid)) {
+			result = L2CAP_CR_LE_SCID_IN_USE;
+			continue;
+		}
+
+		chan = pchan->ops->new_connection(pchan);
+		if (!chan) {
+			result = L2CAP_CR_LE_NO_MEM;
+			continue;
+		}
+
+		bacpy(&chan->src, &conn->hcon->src);
+		bacpy(&chan->dst, &conn->hcon->dst);
+		chan->src_type = bdaddr_src_type(conn->hcon);
+		chan->dst_type = bdaddr_dst_type(conn->hcon);
+		chan->psm  = psm;
+		chan->dcid = scid;
+		chan->omtu = mtu;
+		chan->remote_mps = mps;
+
+		__l2cap_chan_add(conn, chan);
+
+		l2cap_ecred_init(chan, __le16_to_cpu(req->credits));
+
+		/* Init response */
+		if (!pdu.rsp.credits) {
+			pdu.rsp.mtu = cpu_to_le16(chan->imtu);
+			pdu.rsp.mps = cpu_to_le16(chan->mps);
+			pdu.rsp.credits = cpu_to_le16(chan->rx_credits);
+		}
+
+		pdu.dcid[i] = cpu_to_le16(chan->scid);
+
+		__set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
+
+		chan->ident = cmd->ident;
+		chan->mode = L2CAP_MODE_EXT_FLOWCTL;
+
+		if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
+			l2cap_state_change(chan, BT_CONNECT2);
+			defer = true;
+			chan->ops->defer(chan);
+		} else {
+			l2cap_chan_ready(chan);
+		}
+	}
+
+unlock:
+	l2cap_chan_unlock(pchan);
+	mutex_unlock(&conn->chan_lock);
+	l2cap_chan_put(pchan);
+
+response:
+	pdu.rsp.result = cpu_to_le16(result);
+
+	if (defer)
+		return 0;
+
+	l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_CONN_RSP,
+		       sizeof(pdu.rsp) + len, &pdu);
+
+	return 0;
+}
+
+static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn,
+				       struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				       u8 *data)
+{
+	struct l2cap_ecred_conn_rsp *rsp = (void *) data;
+	struct hci_conn *hcon = conn->hcon;
+	u16 mtu, mps, credits, result;
+	struct l2cap_chan *chan, *tmp;
+	int err = 0, sec_level;
+	int i = 0;
+
+	if (cmd_len < sizeof(*rsp))
+		return -EPROTO;
+
+	mtu     = __le16_to_cpu(rsp->mtu);
+	mps     = __le16_to_cpu(rsp->mps);
+	credits = __le16_to_cpu(rsp->credits);
+	result  = __le16_to_cpu(rsp->result);
+
+	BT_DBG("mtu %u mps %u credits %u result 0x%4.4x", mtu, mps, credits,
+	       result);
+
+	mutex_lock(&conn->chan_lock);
+
+	cmd_len -= sizeof(*rsp);
+
+	list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
+		u16 dcid;
+
+		if (chan->ident != cmd->ident ||
+		    chan->mode != L2CAP_MODE_EXT_FLOWCTL ||
+		    chan->state == BT_CONNECTED)
+			continue;
+
+		l2cap_chan_lock(chan);
+
+		/* Check that there is a dcid for each pending channel */
+		if (cmd_len < sizeof(dcid)) {
+			l2cap_chan_del(chan, ECONNREFUSED);
+			l2cap_chan_unlock(chan);
+			continue;
+		}
+
+		dcid = __le16_to_cpu(rsp->dcid[i++]);
+		cmd_len -= sizeof(u16);
+
+		BT_DBG("dcid[%d] 0x%4.4x", i, dcid);
+
+		/* Check if dcid is already in use */
+		if (dcid && __l2cap_get_chan_by_dcid(conn, dcid)) {
+			/* If a device receives a
+			 * L2CAP_CREDIT_BASED_CONNECTION_RSP packet with an
+			 * already-assigned Destination CID, then both the
+			 * original channel and the new channel shall be
+			 * immediately discarded and not used.
+			 */
+			l2cap_chan_del(chan, ECONNREFUSED);
+			l2cap_chan_unlock(chan);
+			chan = __l2cap_get_chan_by_dcid(conn, dcid);
+			l2cap_chan_lock(chan);
+			l2cap_chan_del(chan, ECONNRESET);
+			l2cap_chan_unlock(chan);
+			continue;
+		}
+
+		switch (result) {
+		case L2CAP_CR_LE_AUTHENTICATION:
+		case L2CAP_CR_LE_ENCRYPTION:
+			/* If we already have MITM protection we can't do
+			 * anything.
+			 */
+			if (hcon->sec_level > BT_SECURITY_MEDIUM) {
+				l2cap_chan_del(chan, ECONNREFUSED);
+				break;
+			}
+
+			sec_level = hcon->sec_level + 1;
+			if (chan->sec_level < sec_level)
+				chan->sec_level = sec_level;
+
+			/* We'll need to send a new Connect Request */
+			clear_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags);
+
+			smp_conn_security(hcon, chan->sec_level);
+			break;
+
+		case L2CAP_CR_LE_BAD_PSM:
+			l2cap_chan_del(chan, ECONNREFUSED);
+			break;
+
+		default:
+			/* If dcid was not set it means channels was refused */
+			if (!dcid) {
+				l2cap_chan_del(chan, ECONNREFUSED);
+				break;
+			}
+
+			chan->ident = 0;
+			chan->dcid = dcid;
+			chan->omtu = mtu;
+			chan->remote_mps = mps;
+			chan->tx_credits = credits;
+			l2cap_chan_ready(chan);
+			break;
+		}
+
+		l2cap_chan_unlock(chan);
+	}
+
+	mutex_unlock(&conn->chan_lock);
+
+	return err;
+}
+
+static inline int l2cap_ecred_reconf_req(struct l2cap_conn *conn,
+					 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+					 u8 *data)
+{
+	struct l2cap_ecred_reconf_req *req = (void *) data;
+	struct l2cap_ecred_reconf_rsp rsp;
+	u16 mtu, mps, result;
+	struct l2cap_chan *chan;
+	int i, num_scid;
+
+	if (!enable_ecred)
+		return -EINVAL;
+
+	if (cmd_len < sizeof(*req) || cmd_len - sizeof(*req) % sizeof(u16)) {
+		result = L2CAP_CR_LE_INVALID_PARAMS;
+		goto respond;
+	}
+
+	mtu = __le16_to_cpu(req->mtu);
+	mps = __le16_to_cpu(req->mps);
+
+	BT_DBG("mtu %u mps %u", mtu, mps);
+
+	if (mtu < L2CAP_ECRED_MIN_MTU) {
+		result = L2CAP_RECONF_INVALID_MTU;
+		goto respond;
+	}
+
+	if (mps < L2CAP_ECRED_MIN_MPS) {
+		result = L2CAP_RECONF_INVALID_MPS;
+		goto respond;
+	}
+
+	cmd_len -= sizeof(*req);
+	num_scid = cmd_len / sizeof(u16);
+	result = L2CAP_RECONF_SUCCESS;
+
+	for (i = 0; i < num_scid; i++) {
+		u16 scid;
+
+		scid = __le16_to_cpu(req->scid[i]);
+		if (!scid)
+			return -EPROTO;
+
+		chan = __l2cap_get_chan_by_dcid(conn, scid);
+		if (!chan)
+			continue;
+
+		/* If the MTU value is decreased for any of the included
+		 * channels, then the receiver shall disconnect all
+		 * included channels.
+		 */
+		if (chan->omtu > mtu) {
+			BT_ERR("chan %p decreased MTU %u -> %u", chan,
+			       chan->omtu, mtu);
+			result = L2CAP_RECONF_INVALID_MTU;
+		}
+
+		chan->omtu = mtu;
+		chan->remote_mps = mps;
+	}
+
+respond:
+	rsp.result = cpu_to_le16(result);
+
+	l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_RECONF_RSP, sizeof(rsp),
+		       &rsp);
+
+	return 0;
+}
+
+static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn,
+					 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+					 u8 *data)
+{
+	struct l2cap_chan *chan, *tmp;
+	struct l2cap_ecred_conn_rsp *rsp = (void *) data;
+	u16 result;
+
+	if (cmd_len < sizeof(*rsp))
+		return -EPROTO;
+
+	result = __le16_to_cpu(rsp->result);
+
+	BT_DBG("result 0x%4.4x", rsp->result);
+
+	if (!result)
+		return 0;
+
+	list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
+		if (chan->ident != cmd->ident)
+			continue;
+
+		l2cap_chan_del(chan, ECONNRESET);
+	}
+
+	return 0;
+}
+
+static inline int l2cap_le_command_rej(struct l2cap_conn *conn,
+				       struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				       u8 *data)
+{
+	struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
+	struct l2cap_chan *chan;
+
+	if (cmd_len < sizeof(*rej))
+		return -EPROTO;
+
+	mutex_lock(&conn->chan_lock);
+
+	chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
+	if (!chan)
+		goto done;
+
+	chan = l2cap_chan_hold_unless_zero(chan);
+	if (!chan)
+		goto done;
+
+	l2cap_chan_lock(chan);
+	l2cap_chan_del(chan, ECONNREFUSED);
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+
+done:
+	mutex_unlock(&conn->chan_lock);
+	return 0;
+}
+
+static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
+				   struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				   u8 *data)
+{
+	int err = 0;
+
+	switch (cmd->code) {
+	case L2CAP_COMMAND_REJ:
+		l2cap_le_command_rej(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_CONN_PARAM_UPDATE_REQ:
+		err = l2cap_conn_param_update_req(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_CONN_PARAM_UPDATE_RSP:
+		break;
+
+	case L2CAP_LE_CONN_RSP:
+		l2cap_le_connect_rsp(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_LE_CONN_REQ:
+		err = l2cap_le_connect_req(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_LE_CREDITS:
+		err = l2cap_le_credits(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_ECRED_CONN_REQ:
+		err = l2cap_ecred_conn_req(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_ECRED_CONN_RSP:
+		err = l2cap_ecred_conn_rsp(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_ECRED_RECONF_REQ:
+		err = l2cap_ecred_reconf_req(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_ECRED_RECONF_RSP:
+		err = l2cap_ecred_reconf_rsp(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_DISCONN_REQ:
+		err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_DISCONN_RSP:
+		l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
+		break;
+
+	default:
+		BT_ERR("Unknown LE signaling command 0x%2.2x", cmd->code);
+		err = -EINVAL;
+		break;
+	}
+
+	return err;
+}
+
+static inline void l2cap_le_sig_channel(struct l2cap_conn *conn,
+					struct sk_buff *skb)
+{
+	struct hci_conn *hcon = conn->hcon;
+	struct l2cap_cmd_hdr *cmd;
+	u16 len;
+	int err;
+
+	if (hcon->type != LE_LINK)
+		goto drop;
+
+	if (skb->len < L2CAP_CMD_HDR_SIZE)
+		goto drop;
+
+	cmd = (void *) skb->data;
+	skb_pull(skb, L2CAP_CMD_HDR_SIZE);
+
+	len = le16_to_cpu(cmd->len);
+
+	BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, cmd->ident);
+
+	if (len != skb->len || !cmd->ident) {
+		BT_DBG("corrupted command");
+		goto drop;
+	}
+
+	err = l2cap_le_sig_cmd(conn, cmd, len, skb->data);
+	if (err) {
+		struct l2cap_cmd_rej_unk rej;
+
+		BT_ERR("Wrong link type (%d)", err);
+
+		rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
+		l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ,
+			       sizeof(rej), &rej);
+	}
+
+drop:
+	kfree_skb(skb);
+}
+
+static inline void l2cap_sig_send_rej(struct l2cap_conn *conn, u16 ident)
+{
+	struct l2cap_cmd_rej_unk rej;
+
+	rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
+	l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej);
+}
+
+static inline void l2cap_sig_channel(struct l2cap_conn *conn,
+				     struct sk_buff *skb)
+{
+	struct hci_conn *hcon = conn->hcon;
+	struct l2cap_cmd_hdr *cmd;
+	int err;
+
+	l2cap_raw_recv(conn, skb);
+
+	if (hcon->type != ACL_LINK)
+		goto drop;
+
+	while (skb->len >= L2CAP_CMD_HDR_SIZE) {
+		u16 len;
+
+		cmd = (void *) skb->data;
+		skb_pull(skb, L2CAP_CMD_HDR_SIZE);
+
+		len = le16_to_cpu(cmd->len);
+
+		BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len,
+		       cmd->ident);
+
+		if (len > skb->len || !cmd->ident) {
+			BT_DBG("corrupted command");
+			l2cap_sig_send_rej(conn, cmd->ident);
+			break;
+		}
+
+		err = l2cap_bredr_sig_cmd(conn, cmd, len, skb->data);
+		if (err) {
+			BT_ERR("Wrong link type (%d)", err);
+			l2cap_sig_send_rej(conn, cmd->ident);
+		}
+
+		skb_pull(skb, len);
+	}
+
+	if (skb->len > 0) {
+		BT_DBG("corrupted command");
+		l2cap_sig_send_rej(conn, 0);
+	}
+
+drop:
+	kfree_skb(skb);
+}
+
+static int l2cap_check_fcs(struct l2cap_chan *chan,  struct sk_buff *skb)
+{
+	u16 our_fcs, rcv_fcs;
+	int hdr_size;
+
+	if (test_bit(FLAG_EXT_CTRL, &chan->flags))
+		hdr_size = L2CAP_EXT_HDR_SIZE;
+	else
+		hdr_size = L2CAP_ENH_HDR_SIZE;
+
+	if (chan->fcs == L2CAP_FCS_CRC16) {
+		skb_trim(skb, skb->len - L2CAP_FCS_SIZE);
+		rcv_fcs = get_unaligned_le16(skb->data + skb->len);
+		our_fcs = crc16(0, skb->data - hdr_size, skb->len + hdr_size);
+
+		if (our_fcs != rcv_fcs)
+			return -EBADMSG;
+	}
+	return 0;
+}
+
+static void l2cap_send_i_or_rr_or_rnr(struct l2cap_chan *chan)
+{
+	struct l2cap_ctrl control;
+
+	BT_DBG("chan %p", chan);
+
+	memset(&control, 0, sizeof(control));
+	control.sframe = 1;
+	control.final = 1;
+	control.reqseq = chan->buffer_seq;
+	set_bit(CONN_SEND_FBIT, &chan->conn_state);
+
+	if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
+		control.super = L2CAP_SUPER_RNR;
+		l2cap_send_sframe(chan, &control);
+	}
+
+	if (test_and_clear_bit(CONN_REMOTE_BUSY, &chan->conn_state) &&
+	    chan->unacked_frames > 0)
+		__set_retrans_timer(chan);
+
+	/* Send pending iframes */
+	l2cap_ertm_send(chan);
+
+	if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
+	    test_bit(CONN_SEND_FBIT, &chan->conn_state)) {
+		/* F-bit wasn't sent in an s-frame or i-frame yet, so
+		 * send it now.
+		 */
+		control.super = L2CAP_SUPER_RR;
+		l2cap_send_sframe(chan, &control);
+	}
+}
+
+static void append_skb_frag(struct sk_buff *skb, struct sk_buff *new_frag,
+			    struct sk_buff **last_frag)
+{
+	/* skb->len reflects data in skb as well as all fragments
+	 * skb->data_len reflects only data in fragments
+	 */
+	if (!skb_has_frag_list(skb))
+		skb_shinfo(skb)->frag_list = new_frag;
+
+	new_frag->next = NULL;
+
+	(*last_frag)->next = new_frag;
+	*last_frag = new_frag;
+
+	skb->len += new_frag->len;
+	skb->data_len += new_frag->len;
+	skb->truesize += new_frag->truesize;
+}
+
+static int l2cap_reassemble_sdu(struct l2cap_chan *chan, struct sk_buff *skb,
+				struct l2cap_ctrl *control)
+{
+	int err = -EINVAL;
+
+	switch (control->sar) {
+	case L2CAP_SAR_UNSEGMENTED:
+		if (chan->sdu)
+			break;
+
+		err = chan->ops->recv(chan, skb);
+		break;
+
+	case L2CAP_SAR_START:
+		if (chan->sdu)
+			break;
+
+		if (!pskb_may_pull(skb, L2CAP_SDULEN_SIZE))
+			break;
+
+		chan->sdu_len = get_unaligned_le16(skb->data);
+		skb_pull(skb, L2CAP_SDULEN_SIZE);
+
+		if (chan->sdu_len > chan->imtu) {
+			err = -EMSGSIZE;
+			break;
+		}
+
+		if (skb->len >= chan->sdu_len)
+			break;
+
+		chan->sdu = skb;
+		chan->sdu_last_frag = skb;
+
+		skb = NULL;
+		err = 0;
+		break;
+
+	case L2CAP_SAR_CONTINUE:
+		if (!chan->sdu)
+			break;
+
+		append_skb_frag(chan->sdu, skb,
+				&chan->sdu_last_frag);
+		skb = NULL;
+
+		if (chan->sdu->len >= chan->sdu_len)
+			break;
+
+		err = 0;
+		break;
+
+	case L2CAP_SAR_END:
+		if (!chan->sdu)
+			break;
+
+		append_skb_frag(chan->sdu, skb,
+				&chan->sdu_last_frag);
+		skb = NULL;
+
+		if (chan->sdu->len != chan->sdu_len)
+			break;
+
+		err = chan->ops->recv(chan, chan->sdu);
+
+		if (!err) {
+			/* Reassembly complete */
+			chan->sdu = NULL;
+			chan->sdu_last_frag = NULL;
+			chan->sdu_len = 0;
+		}
+		break;
+	}
+
+	if (err) {
+		kfree_skb(skb);
+		kfree_skb(chan->sdu);
+		chan->sdu = NULL;
+		chan->sdu_last_frag = NULL;
+		chan->sdu_len = 0;
+	}
+
+	return err;
+}
+
+static int l2cap_resegment(struct l2cap_chan *chan)
+{
+	/* Placeholder */
+	return 0;
+}
+
+void l2cap_chan_busy(struct l2cap_chan *chan, int busy)
+{
+	u8 event;
+
+	if (chan->mode != L2CAP_MODE_ERTM)
+		return;
+
+	event = busy ? L2CAP_EV_LOCAL_BUSY_DETECTED : L2CAP_EV_LOCAL_BUSY_CLEAR;
+	l2cap_tx(chan, NULL, NULL, event);
+}
+
+static int l2cap_rx_queued_iframes(struct l2cap_chan *chan)
+{
+	int err = 0;
+	/* Pass sequential frames to l2cap_reassemble_sdu()
+	 * until a gap is encountered.
+	 */
+
+	BT_DBG("chan %p", chan);
+
+	while (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
+		struct sk_buff *skb;
+		BT_DBG("Searching for skb with txseq %d (queue len %d)",
+		       chan->buffer_seq, skb_queue_len(&chan->srej_q));
+
+		skb = l2cap_ertm_seq_in_queue(&chan->srej_q, chan->buffer_seq);
+
+		if (!skb)
+			break;
+
+		skb_unlink(skb, &chan->srej_q);
+		chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
+		err = l2cap_reassemble_sdu(chan, skb, &bt_cb(skb)->l2cap);
+		if (err)
+			break;
+	}
+
+	if (skb_queue_empty(&chan->srej_q)) {
+		chan->rx_state = L2CAP_RX_STATE_RECV;
+		l2cap_send_ack(chan);
+	}
+
+	return err;
+}
+
+static void l2cap_handle_srej(struct l2cap_chan *chan,
+			      struct l2cap_ctrl *control)
+{
+	struct sk_buff *skb;
+
+	BT_DBG("chan %p, control %p", chan, control);
+
+	if (control->reqseq == chan->next_tx_seq) {
+		BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
+		l2cap_send_disconn_req(chan, ECONNRESET);
+		return;
+	}
+
+	skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
+
+	if (skb == NULL) {
+		BT_DBG("Seq %d not available for retransmission",
+		       control->reqseq);
+		return;
+	}
+
+	if (chan->max_tx != 0 && bt_cb(skb)->l2cap.retries >= chan->max_tx) {
+		BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
+		l2cap_send_disconn_req(chan, ECONNRESET);
+		return;
+	}
+
+	clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
+
+	if (control->poll) {
+		l2cap_pass_to_tx(chan, control);
+
+		set_bit(CONN_SEND_FBIT, &chan->conn_state);
+		l2cap_retransmit(chan, control);
+		l2cap_ertm_send(chan);
+
+		if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
+			set_bit(CONN_SREJ_ACT, &chan->conn_state);
+			chan->srej_save_reqseq = control->reqseq;
+		}
+	} else {
+		l2cap_pass_to_tx_fbit(chan, control);
+
+		if (control->final) {
+			if (chan->srej_save_reqseq != control->reqseq ||
+			    !test_and_clear_bit(CONN_SREJ_ACT,
+						&chan->conn_state))
+				l2cap_retransmit(chan, control);
+		} else {
+			l2cap_retransmit(chan, control);
+			if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
+				set_bit(CONN_SREJ_ACT, &chan->conn_state);
+				chan->srej_save_reqseq = control->reqseq;
+			}
+		}
+	}
+}
+
+static void l2cap_handle_rej(struct l2cap_chan *chan,
+			     struct l2cap_ctrl *control)
+{
+	struct sk_buff *skb;
+
+	BT_DBG("chan %p, control %p", chan, control);
+
+	if (control->reqseq == chan->next_tx_seq) {
+		BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
+		l2cap_send_disconn_req(chan, ECONNRESET);
+		return;
+	}
+
+	skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
+
+	if (chan->max_tx && skb &&
+	    bt_cb(skb)->l2cap.retries >= chan->max_tx) {
+		BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
+		l2cap_send_disconn_req(chan, ECONNRESET);
+		return;
+	}
+
+	clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
+
+	l2cap_pass_to_tx(chan, control);
+
+	if (control->final) {
+		if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state))
+			l2cap_retransmit_all(chan, control);
+	} else {
+		l2cap_retransmit_all(chan, control);
+		l2cap_ertm_send(chan);
+		if (chan->tx_state == L2CAP_TX_STATE_WAIT_F)
+			set_bit(CONN_REJ_ACT, &chan->conn_state);
+	}
+}
+
+static u8 l2cap_classify_txseq(struct l2cap_chan *chan, u16 txseq)
+{
+	BT_DBG("chan %p, txseq %d", chan, txseq);
+
+	BT_DBG("last_acked_seq %d, expected_tx_seq %d", chan->last_acked_seq,
+	       chan->expected_tx_seq);
+
+	if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
+		if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
+		    chan->tx_win) {
+			/* See notes below regarding "double poll" and
+			 * invalid packets.
+			 */
+			if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
+				BT_DBG("Invalid/Ignore - after SREJ");
+				return L2CAP_TXSEQ_INVALID_IGNORE;
+			} else {
+				BT_DBG("Invalid - in window after SREJ sent");
+				return L2CAP_TXSEQ_INVALID;
+			}
+		}
+
+		if (chan->srej_list.head == txseq) {
+			BT_DBG("Expected SREJ");
+			return L2CAP_TXSEQ_EXPECTED_SREJ;
+		}
+
+		if (l2cap_ertm_seq_in_queue(&chan->srej_q, txseq)) {
+			BT_DBG("Duplicate SREJ - txseq already stored");
+			return L2CAP_TXSEQ_DUPLICATE_SREJ;
+		}
+
+		if (l2cap_seq_list_contains(&chan->srej_list, txseq)) {
+			BT_DBG("Unexpected SREJ - not requested");
+			return L2CAP_TXSEQ_UNEXPECTED_SREJ;
+		}
+	}
+
+	if (chan->expected_tx_seq == txseq) {
+		if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
+		    chan->tx_win) {
+			BT_DBG("Invalid - txseq outside tx window");
+			return L2CAP_TXSEQ_INVALID;
+		} else {
+			BT_DBG("Expected");
+			return L2CAP_TXSEQ_EXPECTED;
+		}
+	}
+
+	if (__seq_offset(chan, txseq, chan->last_acked_seq) <
+	    __seq_offset(chan, chan->expected_tx_seq, chan->last_acked_seq)) {
+		BT_DBG("Duplicate - expected_tx_seq later than txseq");
+		return L2CAP_TXSEQ_DUPLICATE;
+	}
+
+	if (__seq_offset(chan, txseq, chan->last_acked_seq) >= chan->tx_win) {
+		/* A source of invalid packets is a "double poll" condition,
+		 * where delays cause us to send multiple poll packets.  If
+		 * the remote stack receives and processes both polls,
+		 * sequence numbers can wrap around in such a way that a
+		 * resent frame has a sequence number that looks like new data
+		 * with a sequence gap.  This would trigger an erroneous SREJ
+		 * request.
+		 *
+		 * Fortunately, this is impossible with a tx window that's
+		 * less than half of the maximum sequence number, which allows
+		 * invalid frames to be safely ignored.
+		 *
+		 * With tx window sizes greater than half of the tx window
+		 * maximum, the frame is invalid and cannot be ignored.  This
+		 * causes a disconnect.
+		 */
+
+		if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
+			BT_DBG("Invalid/Ignore - txseq outside tx window");
+			return L2CAP_TXSEQ_INVALID_IGNORE;
+		} else {
+			BT_DBG("Invalid - txseq outside tx window");
+			return L2CAP_TXSEQ_INVALID;
+		}
+	} else {
+		BT_DBG("Unexpected - txseq indicates missing frames");
+		return L2CAP_TXSEQ_UNEXPECTED;
+	}
+}
+
+static int l2cap_rx_state_recv(struct l2cap_chan *chan,
+			       struct l2cap_ctrl *control,
+			       struct sk_buff *skb, u8 event)
+{
+	struct l2cap_ctrl local_control;
+	int err = 0;
+	bool skb_in_use = false;
+
+	BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
+	       event);
+
+	switch (event) {
+	case L2CAP_EV_RECV_IFRAME:
+		switch (l2cap_classify_txseq(chan, control->txseq)) {
+		case L2CAP_TXSEQ_EXPECTED:
+			l2cap_pass_to_tx(chan, control);
+
+			if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
+				BT_DBG("Busy, discarding expected seq %d",
+				       control->txseq);
+				break;
+			}
+
+			chan->expected_tx_seq = __next_seq(chan,
+							   control->txseq);
+
+			chan->buffer_seq = chan->expected_tx_seq;
+			skb_in_use = true;
+
+			/* l2cap_reassemble_sdu may free skb, hence invalidate
+			 * control, so make a copy in advance to use it after
+			 * l2cap_reassemble_sdu returns and to avoid the race
+			 * condition, for example:
+			 *
+			 * The current thread calls:
+			 *   l2cap_reassemble_sdu
+			 *     chan->ops->recv == l2cap_sock_recv_cb
+			 *       __sock_queue_rcv_skb
+			 * Another thread calls:
+			 *   bt_sock_recvmsg
+			 *     skb_recv_datagram
+			 *     skb_free_datagram
+			 * Then the current thread tries to access control, but
+			 * it was freed by skb_free_datagram.
+			 */
+			local_control = *control;
+			err = l2cap_reassemble_sdu(chan, skb, control);
+			if (err)
+				break;
+
+			if (local_control.final) {
+				if (!test_and_clear_bit(CONN_REJ_ACT,
+							&chan->conn_state)) {
+					local_control.final = 0;
+					l2cap_retransmit_all(chan, &local_control);
+					l2cap_ertm_send(chan);
+				}
+			}
+
+			if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
+				l2cap_send_ack(chan);
+			break;
+		case L2CAP_TXSEQ_UNEXPECTED:
+			l2cap_pass_to_tx(chan, control);
+
+			/* Can't issue SREJ frames in the local busy state.
+			 * Drop this frame, it will be seen as missing
+			 * when local busy is exited.
+			 */
+			if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
+				BT_DBG("Busy, discarding unexpected seq %d",
+				       control->txseq);
+				break;
+			}
+
+			/* There was a gap in the sequence, so an SREJ
+			 * must be sent for each missing frame.  The
+			 * current frame is stored for later use.
+			 */
+			skb_queue_tail(&chan->srej_q, skb);
+			skb_in_use = true;
+			BT_DBG("Queued %p (queue len %d)", skb,
+			       skb_queue_len(&chan->srej_q));
+
+			clear_bit(CONN_SREJ_ACT, &chan->conn_state);
+			l2cap_seq_list_clear(&chan->srej_list);
+			l2cap_send_srej(chan, control->txseq);
+
+			chan->rx_state = L2CAP_RX_STATE_SREJ_SENT;
+			break;
+		case L2CAP_TXSEQ_DUPLICATE:
+			l2cap_pass_to_tx(chan, control);
+			break;
+		case L2CAP_TXSEQ_INVALID_IGNORE:
+			break;
+		case L2CAP_TXSEQ_INVALID:
+		default:
+			l2cap_send_disconn_req(chan, ECONNRESET);
+			break;
+		}
+		break;
+	case L2CAP_EV_RECV_RR:
+		l2cap_pass_to_tx(chan, control);
+		if (control->final) {
+			clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
+
+			if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state) &&
+			    !__chan_is_moving(chan)) {
+				control->final = 0;
+				l2cap_retransmit_all(chan, control);
+			}
+
+			l2cap_ertm_send(chan);
+		} else if (control->poll) {
+			l2cap_send_i_or_rr_or_rnr(chan);
+		} else {
+			if (test_and_clear_bit(CONN_REMOTE_BUSY,
+					       &chan->conn_state) &&
+			    chan->unacked_frames)
+				__set_retrans_timer(chan);
+
+			l2cap_ertm_send(chan);
+		}
+		break;
+	case L2CAP_EV_RECV_RNR:
+		set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
+		l2cap_pass_to_tx(chan, control);
+		if (control && control->poll) {
+			set_bit(CONN_SEND_FBIT, &chan->conn_state);
+			l2cap_send_rr_or_rnr(chan, 0);
+		}
+		__clear_retrans_timer(chan);
+		l2cap_seq_list_clear(&chan->retrans_list);
+		break;
+	case L2CAP_EV_RECV_REJ:
+		l2cap_handle_rej(chan, control);
+		break;
+	case L2CAP_EV_RECV_SREJ:
+		l2cap_handle_srej(chan, control);
+		break;
+	default:
+		break;
+	}
+
+	if (skb && !skb_in_use) {
+		BT_DBG("Freeing %p", skb);
+		kfree_skb(skb);
+	}
+
+	return err;
+}
+
+static int l2cap_rx_state_srej_sent(struct l2cap_chan *chan,
+				    struct l2cap_ctrl *control,
+				    struct sk_buff *skb, u8 event)
+{
+	int err = 0;
+	u16 txseq = control->txseq;
+	bool skb_in_use = false;
+
+	BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
+	       event);
+
+	switch (event) {
+	case L2CAP_EV_RECV_IFRAME:
+		switch (l2cap_classify_txseq(chan, txseq)) {
+		case L2CAP_TXSEQ_EXPECTED:
+			/* Keep frame for reassembly later */
+			l2cap_pass_to_tx(chan, control);
+			skb_queue_tail(&chan->srej_q, skb);
+			skb_in_use = true;
+			BT_DBG("Queued %p (queue len %d)", skb,
+			       skb_queue_len(&chan->srej_q));
+
+			chan->expected_tx_seq = __next_seq(chan, txseq);
+			break;
+		case L2CAP_TXSEQ_EXPECTED_SREJ:
+			l2cap_seq_list_pop(&chan->srej_list);
+
+			l2cap_pass_to_tx(chan, control);
+			skb_queue_tail(&chan->srej_q, skb);
+			skb_in_use = true;
+			BT_DBG("Queued %p (queue len %d)", skb,
+			       skb_queue_len(&chan->srej_q));
+
+			err = l2cap_rx_queued_iframes(chan);
+			if (err)
+				break;
+
+			break;
+		case L2CAP_TXSEQ_UNEXPECTED:
+			/* Got a frame that can't be reassembled yet.
+			 * Save it for later, and send SREJs to cover
+			 * the missing frames.
+			 */
+			skb_queue_tail(&chan->srej_q, skb);
+			skb_in_use = true;
+			BT_DBG("Queued %p (queue len %d)", skb,
+			       skb_queue_len(&chan->srej_q));
+
+			l2cap_pass_to_tx(chan, control);
+			l2cap_send_srej(chan, control->txseq);
+			break;
+		case L2CAP_TXSEQ_UNEXPECTED_SREJ:
+			/* This frame was requested with an SREJ, but
+			 * some expected retransmitted frames are
+			 * missing.  Request retransmission of missing
+			 * SREJ'd frames.
+			 */
+			skb_queue_tail(&chan->srej_q, skb);
+			skb_in_use = true;
+			BT_DBG("Queued %p (queue len %d)", skb,
+			       skb_queue_len(&chan->srej_q));
+
+			l2cap_pass_to_tx(chan, control);
+			l2cap_send_srej_list(chan, control->txseq);
+			break;
+		case L2CAP_TXSEQ_DUPLICATE_SREJ:
+			/* We've already queued this frame.  Drop this copy. */
+			l2cap_pass_to_tx(chan, control);
+			break;
+		case L2CAP_TXSEQ_DUPLICATE:
+			/* Expecting a later sequence number, so this frame
+			 * was already received.  Ignore it completely.
+			 */
+			break;
+		case L2CAP_TXSEQ_INVALID_IGNORE:
+			break;
+		case L2CAP_TXSEQ_INVALID:
+		default:
+			l2cap_send_disconn_req(chan, ECONNRESET);
+			break;
+		}
+		break;
+	case L2CAP_EV_RECV_RR:
+		l2cap_pass_to_tx(chan, control);
+		if (control->final) {
+			clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
+
+			if (!test_and_clear_bit(CONN_REJ_ACT,
+						&chan->conn_state)) {
+				control->final = 0;
+				l2cap_retransmit_all(chan, control);
+			}
+
+			l2cap_ertm_send(chan);
+		} else if (control->poll) {
+			if (test_and_clear_bit(CONN_REMOTE_BUSY,
+					       &chan->conn_state) &&
+			    chan->unacked_frames) {
+				__set_retrans_timer(chan);
+			}
+
+			set_bit(CONN_SEND_FBIT, &chan->conn_state);
+			l2cap_send_srej_tail(chan);
+		} else {
+			if (test_and_clear_bit(CONN_REMOTE_BUSY,
+					       &chan->conn_state) &&
+			    chan->unacked_frames)
+				__set_retrans_timer(chan);
+
+			l2cap_send_ack(chan);
+		}
+		break;
+	case L2CAP_EV_RECV_RNR:
+		set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
+		l2cap_pass_to_tx(chan, control);
+		if (control->poll) {
+			l2cap_send_srej_tail(chan);
+		} else {
+			struct l2cap_ctrl rr_control;
+			memset(&rr_control, 0, sizeof(rr_control));
+			rr_control.sframe = 1;
+			rr_control.super = L2CAP_SUPER_RR;
+			rr_control.reqseq = chan->buffer_seq;
+			l2cap_send_sframe(chan, &rr_control);
+		}
+
+		break;
+	case L2CAP_EV_RECV_REJ:
+		l2cap_handle_rej(chan, control);
+		break;
+	case L2CAP_EV_RECV_SREJ:
+		l2cap_handle_srej(chan, control);
+		break;
+	}
+
+	if (skb && !skb_in_use) {
+		BT_DBG("Freeing %p", skb);
+		kfree_skb(skb);
+	}
+
+	return err;
+}
+
+static int l2cap_finish_move(struct l2cap_chan *chan)
+{
+	BT_DBG("chan %p", chan);
+
+	chan->rx_state = L2CAP_RX_STATE_RECV;
+
+	if (chan->hs_hcon)
+		chan->conn->mtu = chan->hs_hcon->hdev->block_mtu;
+	else
+		chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
+
+	return l2cap_resegment(chan);
+}
+
+static int l2cap_rx_state_wait_p(struct l2cap_chan *chan,
+				 struct l2cap_ctrl *control,
+				 struct sk_buff *skb, u8 event)
+{
+	int err;
+
+	BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
+	       event);
+
+	if (!control->poll)
+		return -EPROTO;
+
+	l2cap_process_reqseq(chan, control->reqseq);
+
+	if (!skb_queue_empty(&chan->tx_q))
+		chan->tx_send_head = skb_peek(&chan->tx_q);
+	else
+		chan->tx_send_head = NULL;
+
+	/* Rewind next_tx_seq to the point expected
+	 * by the receiver.
+	 */
+	chan->next_tx_seq = control->reqseq;
+	chan->unacked_frames = 0;
+
+	err = l2cap_finish_move(chan);
+	if (err)
+		return err;
+
+	set_bit(CONN_SEND_FBIT, &chan->conn_state);
+	l2cap_send_i_or_rr_or_rnr(chan);
+
+	if (event == L2CAP_EV_RECV_IFRAME)
+		return -EPROTO;
+
+	return l2cap_rx_state_recv(chan, control, NULL, event);
+}
+
+static int l2cap_rx_state_wait_f(struct l2cap_chan *chan,
+				 struct l2cap_ctrl *control,
+				 struct sk_buff *skb, u8 event)
+{
+	int err;
+
+	if (!control->final)
+		return -EPROTO;
+
+	clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
+
+	chan->rx_state = L2CAP_RX_STATE_RECV;
+	l2cap_process_reqseq(chan, control->reqseq);
+
+	if (!skb_queue_empty(&chan->tx_q))
+		chan->tx_send_head = skb_peek(&chan->tx_q);
+	else
+		chan->tx_send_head = NULL;
+
+	/* Rewind next_tx_seq to the point expected
+	 * by the receiver.
+	 */
+	chan->next_tx_seq = control->reqseq;
+	chan->unacked_frames = 0;
+
+	if (chan->hs_hcon)
+		chan->conn->mtu = chan->hs_hcon->hdev->block_mtu;
+	else
+		chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
+
+	err = l2cap_resegment(chan);
+
+	if (!err)
+		err = l2cap_rx_state_recv(chan, control, skb, event);
+
+	return err;
+}
+
+static bool __valid_reqseq(struct l2cap_chan *chan, u16 reqseq)
+{
+	/* Make sure reqseq is for a packet that has been sent but not acked */
+	u16 unacked;
+
+	unacked = __seq_offset(chan, chan->next_tx_seq, chan->expected_ack_seq);
+	return __seq_offset(chan, chan->next_tx_seq, reqseq) <= unacked;
+}
+
+static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
+		    struct sk_buff *skb, u8 event)
+{
+	int err = 0;
+
+	BT_DBG("chan %p, control %p, skb %p, event %d, state %d", chan,
+	       control, skb, event, chan->rx_state);
+
+	if (__valid_reqseq(chan, control->reqseq)) {
+		switch (chan->rx_state) {
+		case L2CAP_RX_STATE_RECV:
+			err = l2cap_rx_state_recv(chan, control, skb, event);
+			break;
+		case L2CAP_RX_STATE_SREJ_SENT:
+			err = l2cap_rx_state_srej_sent(chan, control, skb,
+						       event);
+			break;
+		case L2CAP_RX_STATE_WAIT_P:
+			err = l2cap_rx_state_wait_p(chan, control, skb, event);
+			break;
+		case L2CAP_RX_STATE_WAIT_F:
+			err = l2cap_rx_state_wait_f(chan, control, skb, event);
+			break;
+		default:
+			/* shut it down */
+			break;
+		}
+	} else {
+		BT_DBG("Invalid reqseq %d (next_tx_seq %d, expected_ack_seq %d",
+		       control->reqseq, chan->next_tx_seq,
+		       chan->expected_ack_seq);
+		l2cap_send_disconn_req(chan, ECONNRESET);
+	}
+
+	return err;
+}
+
+static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
+			   struct sk_buff *skb)
+{
+	/* l2cap_reassemble_sdu may free skb, hence invalidate control, so store
+	 * the txseq field in advance to use it after l2cap_reassemble_sdu
+	 * returns and to avoid the race condition, for example:
+	 *
+	 * The current thread calls:
+	 *   l2cap_reassemble_sdu
+	 *     chan->ops->recv == l2cap_sock_recv_cb
+	 *       __sock_queue_rcv_skb
+	 * Another thread calls:
+	 *   bt_sock_recvmsg
+	 *     skb_recv_datagram
+	 *     skb_free_datagram
+	 * Then the current thread tries to access control, but it was freed by
+	 * skb_free_datagram.
+	 */
+	u16 txseq = control->txseq;
+
+	BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb,
+	       chan->rx_state);
+
+	if (l2cap_classify_txseq(chan, txseq) == L2CAP_TXSEQ_EXPECTED) {
+		l2cap_pass_to_tx(chan, control);
+
+		BT_DBG("buffer_seq %u->%u", chan->buffer_seq,
+		       __next_seq(chan, chan->buffer_seq));
+
+		chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
+
+		l2cap_reassemble_sdu(chan, skb, control);
+	} else {
+		if (chan->sdu) {
+			kfree_skb(chan->sdu);
+			chan->sdu = NULL;
+		}
+		chan->sdu_last_frag = NULL;
+		chan->sdu_len = 0;
+
+		if (skb) {
+			BT_DBG("Freeing %p", skb);
+			kfree_skb(skb);
+		}
+	}
+
+	chan->last_acked_seq = txseq;
+	chan->expected_tx_seq = __next_seq(chan, txseq);
+
+	return 0;
+}
+
+static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
+{
+	struct l2cap_ctrl *control = &bt_cb(skb)->l2cap;
+	u16 len;
+	u8 event;
+
+	__unpack_control(chan, skb);
+
+	len = skb->len;
+
+	/*
+	 * We can just drop the corrupted I-frame here.
+	 * Receiver will miss it and start proper recovery
+	 * procedures and ask for retransmission.
+	 */
+	if (l2cap_check_fcs(chan, skb))
+		goto drop;
+
+	if (!control->sframe && control->sar == L2CAP_SAR_START)
+		len -= L2CAP_SDULEN_SIZE;
+
+	if (chan->fcs == L2CAP_FCS_CRC16)
+		len -= L2CAP_FCS_SIZE;
+
+	if (len > chan->mps) {
+		l2cap_send_disconn_req(chan, ECONNRESET);
+		goto drop;
+	}
+
+	if (chan->ops->filter) {
+		if (chan->ops->filter(chan, skb))
+			goto drop;
+	}
+
+	if (!control->sframe) {
+		int err;
+
+		BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d",
+		       control->sar, control->reqseq, control->final,
+		       control->txseq);
+
+		/* Validate F-bit - F=0 always valid, F=1 only
+		 * valid in TX WAIT_F
+		 */
+		if (control->final && chan->tx_state != L2CAP_TX_STATE_WAIT_F)
+			goto drop;
+
+		if (chan->mode != L2CAP_MODE_STREAMING) {
+			event = L2CAP_EV_RECV_IFRAME;
+			err = l2cap_rx(chan, control, skb, event);
+		} else {
+			err = l2cap_stream_rx(chan, control, skb);
+		}
+
+		if (err)
+			l2cap_send_disconn_req(chan, ECONNRESET);
+	} else {
+		const u8 rx_func_to_event[4] = {
+			L2CAP_EV_RECV_RR, L2CAP_EV_RECV_REJ,
+			L2CAP_EV_RECV_RNR, L2CAP_EV_RECV_SREJ
+		};
+
+		/* Only I-frames are expected in streaming mode */
+		if (chan->mode == L2CAP_MODE_STREAMING)
+			goto drop;
+
+		BT_DBG("sframe reqseq %d, final %d, poll %d, super %d",
+		       control->reqseq, control->final, control->poll,
+		       control->super);
+
+		if (len != 0) {
+			BT_ERR("Trailing bytes: %d in sframe", len);
+			l2cap_send_disconn_req(chan, ECONNRESET);
+			goto drop;
+		}
+
+		/* Validate F and P bits */
+		if (control->final && (control->poll ||
+				       chan->tx_state != L2CAP_TX_STATE_WAIT_F))
+			goto drop;
+
+		event = rx_func_to_event[control->super];
+		if (l2cap_rx(chan, control, skb, event))
+			l2cap_send_disconn_req(chan, ECONNRESET);
+	}
+
+	return 0;
+
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+
+static void l2cap_chan_le_send_credits(struct l2cap_chan *chan)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct l2cap_le_credits pkt;
+	u16 return_credits;
+
+	return_credits = (chan->imtu / chan->mps) + 1;
+
+	if (chan->rx_credits >= return_credits)
+		return;
+
+	return_credits -= chan->rx_credits;
+
+	BT_DBG("chan %p returning %u credits to sender", chan, return_credits);
+
+	chan->rx_credits += return_credits;
+
+	pkt.cid     = cpu_to_le16(chan->scid);
+	pkt.credits = cpu_to_le16(return_credits);
+
+	chan->ident = l2cap_get_ident(conn);
+
+	l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt);
+}
+
+static int l2cap_ecred_recv(struct l2cap_chan *chan, struct sk_buff *skb)
+{
+	int err;
+
+	BT_DBG("SDU reassemble complete: chan %p skb->len %u", chan, skb->len);
+
+	/* Wait recv to confirm reception before updating the credits */
+	err = chan->ops->recv(chan, skb);
+
+	/* Update credits whenever an SDU is received */
+	l2cap_chan_le_send_credits(chan);
+
+	return err;
+}
+
+static int l2cap_ecred_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
+{
+	int err;
+
+	if (!chan->rx_credits) {
+		BT_ERR("No credits to receive LE L2CAP data");
+		l2cap_send_disconn_req(chan, ECONNRESET);
+		return -ENOBUFS;
+	}
+
+	if (chan->imtu < skb->len) {
+		BT_ERR("Too big LE L2CAP PDU");
+		return -ENOBUFS;
+	}
+
+	chan->rx_credits--;
+	BT_DBG("rx_credits %u -> %u", chan->rx_credits + 1, chan->rx_credits);
+
+	/* Update if remote had run out of credits, this should only happens
+	 * if the remote is not using the entire MPS.
+	 */
+	if (!chan->rx_credits)
+		l2cap_chan_le_send_credits(chan);
+
+	err = 0;
+
+	if (!chan->sdu) {
+		u16 sdu_len;
+
+		sdu_len = get_unaligned_le16(skb->data);
+		skb_pull(skb, L2CAP_SDULEN_SIZE);
+
+		BT_DBG("Start of new SDU. sdu_len %u skb->len %u imtu %u",
+		       sdu_len, skb->len, chan->imtu);
+
+		if (sdu_len > chan->imtu) {
+			BT_ERR("Too big LE L2CAP SDU length received");
+			err = -EMSGSIZE;
+			goto failed;
+		}
+
+		if (skb->len > sdu_len) {
+			BT_ERR("Too much LE L2CAP data received");
+			err = -EINVAL;
+			goto failed;
+		}
+
+		if (skb->len == sdu_len)
+			return l2cap_ecred_recv(chan, skb);
+
+		chan->sdu = skb;
+		chan->sdu_len = sdu_len;
+		chan->sdu_last_frag = skb;
+
+		/* Detect if remote is not able to use the selected MPS */
+		if (skb->len + L2CAP_SDULEN_SIZE < chan->mps) {
+			u16 mps_len = skb->len + L2CAP_SDULEN_SIZE;
+
+			/* Adjust the number of credits */
+			BT_DBG("chan->mps %u -> %u", chan->mps, mps_len);
+			chan->mps = mps_len;
+			l2cap_chan_le_send_credits(chan);
+		}
+
+		return 0;
+	}
+
+	BT_DBG("SDU fragment. chan->sdu->len %u skb->len %u chan->sdu_len %u",
+	       chan->sdu->len, skb->len, chan->sdu_len);
+
+	if (chan->sdu->len + skb->len > chan->sdu_len) {
+		BT_ERR("Too much LE L2CAP data received");
+		err = -EINVAL;
+		goto failed;
+	}
+
+	append_skb_frag(chan->sdu, skb, &chan->sdu_last_frag);
+	skb = NULL;
+
+	if (chan->sdu->len == chan->sdu_len) {
+		err = l2cap_ecred_recv(chan, chan->sdu);
+		if (!err) {
+			chan->sdu = NULL;
+			chan->sdu_last_frag = NULL;
+			chan->sdu_len = 0;
+		}
+	}
+
+failed:
+	if (err) {
+		kfree_skb(skb);
+		kfree_skb(chan->sdu);
+		chan->sdu = NULL;
+		chan->sdu_last_frag = NULL;
+		chan->sdu_len = 0;
+	}
+
+	/* We can't return an error here since we took care of the skb
+	 * freeing internally. An error return would cause the caller to
+	 * do a double-free of the skb.
+	 */
+	return 0;
+}
+
+static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid,
+			       struct sk_buff *skb)
+{
+	struct l2cap_chan *chan;
+
+	chan = l2cap_get_chan_by_scid(conn, cid);
+	if (!chan) {
+		if (cid == L2CAP_CID_A2MP) {
+			chan = a2mp_channel_create(conn, skb);
+			if (!chan) {
+				kfree_skb(skb);
+				return;
+			}
+
+			l2cap_chan_hold(chan);
+			l2cap_chan_lock(chan);
+		} else {
+			BT_DBG("unknown cid 0x%4.4x", cid);
+			/* Drop packet and return */
+			kfree_skb(skb);
+			return;
+		}
+	}
+
+	BT_DBG("chan %p, len %d", chan, skb->len);
+
+	/* If we receive data on a fixed channel before the info req/rsp
+	 * procedure is done simply assume that the channel is supported
+	 * and mark it as ready.
+	 */
+	if (chan->chan_type == L2CAP_CHAN_FIXED)
+		l2cap_chan_ready(chan);
+
+	if (chan->state != BT_CONNECTED)
+		goto drop;
+
+	switch (chan->mode) {
+	case L2CAP_MODE_LE_FLOWCTL:
+	case L2CAP_MODE_EXT_FLOWCTL:
+		if (l2cap_ecred_data_rcv(chan, skb) < 0)
+			goto drop;
+
+		goto done;
+
+	case L2CAP_MODE_BASIC:
+		/* If socket recv buffers overflows we drop data here
+		 * which is *bad* because L2CAP has to be reliable.
+		 * But we don't have any other choice. L2CAP doesn't
+		 * provide flow control mechanism. */
+
+		if (chan->imtu < skb->len) {
+			BT_ERR("Dropping L2CAP data: receive buffer overflow");
+			goto drop;
+		}
+
+		if (!chan->ops->recv(chan, skb))
+			goto done;
+		break;
+
+	case L2CAP_MODE_ERTM:
+	case L2CAP_MODE_STREAMING:
+		l2cap_data_rcv(chan, skb);
+		goto done;
+
+	default:
+		BT_DBG("chan %p: bad mode 0x%2.2x", chan, chan->mode);
+		break;
+	}
+
+drop:
+	kfree_skb(skb);
+
+done:
+	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
+}
+
+static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm,
+				  struct sk_buff *skb)
+{
+	struct hci_conn *hcon = conn->hcon;
+	struct l2cap_chan *chan;
+
+	if (hcon->type != ACL_LINK)
+		goto free_skb;
+
+	chan = l2cap_global_chan_by_psm(0, psm, &hcon->src, &hcon->dst,
+					ACL_LINK);
+	if (!chan)
+		goto free_skb;
+
+	BT_DBG("chan %p, len %d", chan, skb->len);
+
+	if (chan->state != BT_BOUND && chan->state != BT_CONNECTED)
+		goto drop;
+
+	if (chan->imtu < skb->len)
+		goto drop;
+
+	/* Store remote BD_ADDR and PSM for msg_name */
+	bacpy(&bt_cb(skb)->l2cap.bdaddr, &hcon->dst);
+	bt_cb(skb)->l2cap.psm = psm;
+
+	if (!chan->ops->recv(chan, skb)) {
+		l2cap_chan_put(chan);
+		return;
+	}
+
+drop:
+	l2cap_chan_put(chan);
+free_skb:
+	kfree_skb(skb);
+}
+
+static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb)
+{
+	struct l2cap_hdr *lh = (void *) skb->data;
+	struct hci_conn *hcon = conn->hcon;
+	u16 cid, len;
+	__le16 psm;
+
+	if (hcon->state != BT_CONNECTED) {
+		BT_DBG("queueing pending rx skb");
+		skb_queue_tail(&conn->pending_rx, skb);
+		return;
+	}
+
+	skb_pull(skb, L2CAP_HDR_SIZE);
+	cid = __le16_to_cpu(lh->cid);
+	len = __le16_to_cpu(lh->len);
+
+	if (len != skb->len) {
+		kfree_skb(skb);
+		return;
+	}
+
+	/* Since we can't actively block incoming LE connections we must
+	 * at least ensure that we ignore incoming data from them.
+	 */
+	if (hcon->type == LE_LINK &&
+	    hci_bdaddr_list_lookup(&hcon->hdev->reject_list, &hcon->dst,
+				   bdaddr_dst_type(hcon))) {
+		kfree_skb(skb);
+		return;
+	}
+
+	BT_DBG("len %d, cid 0x%4.4x", len, cid);
+
+	switch (cid) {
+	case L2CAP_CID_SIGNALING:
+		l2cap_sig_channel(conn, skb);
+		break;
+
+	case L2CAP_CID_CONN_LESS:
+		psm = get_unaligned((__le16 *) skb->data);
+		skb_pull(skb, L2CAP_PSMLEN_SIZE);
+		l2cap_conless_channel(conn, psm, skb);
+		break;
+
+	case L2CAP_CID_LE_SIGNALING:
+		l2cap_le_sig_channel(conn, skb);
+		break;
+
+	default:
+		l2cap_data_channel(conn, cid, skb);
+		break;
+	}
+}
+
+static void process_pending_rx(struct work_struct *work)
+{
+	struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
+					       pending_rx_work);
+	struct sk_buff *skb;
+
+	BT_DBG("");
+
+	while ((skb = skb_dequeue(&conn->pending_rx)))
+		l2cap_recv_frame(conn, skb);
+}
+
+static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon)
+{
+	struct l2cap_conn *conn = hcon->l2cap_data;
+	struct hci_chan *hchan;
+
+	if (conn)
+		return conn;
+
+	hchan = hci_chan_create(hcon);
+	if (!hchan)
+		return NULL;
+
+	conn = kzalloc(sizeof(*conn), GFP_KERNEL);
+	if (!conn) {
+		hci_chan_del(hchan);
+		return NULL;
+	}
+
+	kref_init(&conn->ref);
+	hcon->l2cap_data = conn;
+	conn->hcon = hci_conn_get(hcon);
+	conn->hchan = hchan;
+
+	BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan);
+
+	switch (hcon->type) {
+	case LE_LINK:
+		if (hcon->hdev->le_mtu) {
+			conn->mtu = hcon->hdev->le_mtu;
+			break;
+		}
+		fallthrough;
+	default:
+		conn->mtu = hcon->hdev->acl_mtu;
+		break;
+	}
+
+	conn->feat_mask = 0;
+
+	conn->local_fixed_chan = L2CAP_FC_SIG_BREDR | L2CAP_FC_CONNLESS;
+
+	if (hcon->type == ACL_LINK &&
+	    hci_dev_test_flag(hcon->hdev, HCI_HS_ENABLED))
+		conn->local_fixed_chan |= L2CAP_FC_A2MP;
+
+	if (hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED) &&
+	    (bredr_sc_enabled(hcon->hdev) ||
+	     hci_dev_test_flag(hcon->hdev, HCI_FORCE_BREDR_SMP)))
+		conn->local_fixed_chan |= L2CAP_FC_SMP_BREDR;
+
+	mutex_init(&conn->ident_lock);
+	mutex_init(&conn->chan_lock);
+
+	INIT_LIST_HEAD(&conn->chan_l);
+	INIT_LIST_HEAD(&conn->users);
+
+	INIT_DELAYED_WORK(&conn->info_timer, l2cap_info_timeout);
+
+	skb_queue_head_init(&conn->pending_rx);
+	INIT_WORK(&conn->pending_rx_work, process_pending_rx);
+	INIT_WORK(&conn->id_addr_update_work, l2cap_conn_update_id_addr);
+
+	conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
+
+	return conn;
+}
+
+static bool is_valid_psm(u16 psm, u8 dst_type)
+{
+	if (!psm)
+		return false;
+
+	if (bdaddr_type_is_le(dst_type))
+		return (psm <= 0x00ff);
+
+	/* PSM must be odd and lsb of upper byte must be 0 */
+	return ((psm & 0x0101) == 0x0001);
+}
+
+struct l2cap_chan_data {
+	struct l2cap_chan *chan;
+	struct pid *pid;
+	int count;
+};
+
+static void l2cap_chan_by_pid(struct l2cap_chan *chan, void *data)
+{
+	struct l2cap_chan_data *d = data;
+	struct pid *pid;
+
+	if (chan == d->chan)
+		return;
+
+	if (!test_bit(FLAG_DEFER_SETUP, &chan->flags))
+		return;
+
+	pid = chan->ops->get_peer_pid(chan);
+
+	/* Only count deferred channels with the same PID/PSM */
+	if (d->pid != pid || chan->psm != d->chan->psm || chan->ident ||
+	    chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT)
+		return;
+
+	d->count++;
+}
+
+int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
+		       bdaddr_t *dst, u8 dst_type)
+{
+	struct l2cap_conn *conn;
+	struct hci_conn *hcon;
+	struct hci_dev *hdev;
+	int err;
+
+	BT_DBG("%pMR -> %pMR (type %u) psm 0x%4.4x mode 0x%2.2x", &chan->src,
+	       dst, dst_type, __le16_to_cpu(psm), chan->mode);
+
+	hdev = hci_get_route(dst, &chan->src, chan->src_type);
+	if (!hdev)
+		return -EHOSTUNREACH;
+
+	hci_dev_lock(hdev);
+
+	if (!is_valid_psm(__le16_to_cpu(psm), dst_type) && !cid &&
+	    chan->chan_type != L2CAP_CHAN_RAW) {
+		err = -EINVAL;
+		goto done;
+	}
+
+	if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !psm) {
+		err = -EINVAL;
+		goto done;
+	}
+
+	if (chan->chan_type == L2CAP_CHAN_FIXED && !cid) {
+		err = -EINVAL;
+		goto done;
+	}
+
+	switch (chan->mode) {
+	case L2CAP_MODE_BASIC:
+		break;
+	case L2CAP_MODE_LE_FLOWCTL:
+		break;
+	case L2CAP_MODE_EXT_FLOWCTL:
+		if (!enable_ecred) {
+			err = -EOPNOTSUPP;
+			goto done;
+		}
+		break;
+	case L2CAP_MODE_ERTM:
+	case L2CAP_MODE_STREAMING:
+		if (!disable_ertm)
+			break;
+		fallthrough;
+	default:
+		err = -EOPNOTSUPP;
+		goto done;
+	}
+
+	switch (chan->state) {
+	case BT_CONNECT:
+	case BT_CONNECT2:
+	case BT_CONFIG:
+		/* Already connecting */
+		err = 0;
+		goto done;
+
+	case BT_CONNECTED:
+		/* Already connected */
+		err = -EISCONN;
+		goto done;
+
+	case BT_OPEN:
+	case BT_BOUND:
+		/* Can connect */
+		break;
+
+	default:
+		err = -EBADFD;
+		goto done;
+	}
+
+	/* Set destination address and psm */
+	bacpy(&chan->dst, dst);
+	chan->dst_type = dst_type;
+
+	chan->psm = psm;
+	chan->dcid = cid;
+
+	if (bdaddr_type_is_le(dst_type)) {
+		/* Convert from L2CAP channel address type to HCI address type
+		 */
+		if (dst_type == BDADDR_LE_PUBLIC)
+			dst_type = ADDR_LE_DEV_PUBLIC;
+		else
+			dst_type = ADDR_LE_DEV_RANDOM;
+
+		if (hci_dev_test_flag(hdev, HCI_ADVERTISING))
+			hcon = hci_connect_le(hdev, dst, dst_type, false,
+					      chan->sec_level,
+					      HCI_LE_CONN_TIMEOUT,
+					      HCI_ROLE_SLAVE);
+		else
+			hcon = hci_connect_le_scan(hdev, dst, dst_type,
+						   chan->sec_level,
+						   HCI_LE_CONN_TIMEOUT,
+						   CONN_REASON_L2CAP_CHAN);
+
+	} else {
+		u8 auth_type = l2cap_get_auth_type(chan);
+		hcon = hci_connect_acl(hdev, dst, chan->sec_level, auth_type,
+				       CONN_REASON_L2CAP_CHAN);
+	}
+
+	if (IS_ERR(hcon)) {
+		err = PTR_ERR(hcon);
+		goto done;
+	}
+
+	conn = l2cap_conn_add(hcon);
+	if (!conn) {
+		hci_conn_drop(hcon);
+		err = -ENOMEM;
+		goto done;
+	}
+
+	if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) {
+		struct l2cap_chan_data data;
+
+		data.chan = chan;
+		data.pid = chan->ops->get_peer_pid(chan);
+		data.count = 1;
+
+		l2cap_chan_list(conn, l2cap_chan_by_pid, &data);
+
+		/* Check if there isn't too many channels being connected */
+		if (data.count > L2CAP_ECRED_CONN_SCID_MAX) {
+			hci_conn_drop(hcon);
+			err = -EPROTO;
+			goto done;
+		}
+	}
+
+	mutex_lock(&conn->chan_lock);
+	l2cap_chan_lock(chan);
+
+	if (cid && __l2cap_get_chan_by_dcid(conn, cid)) {
+		hci_conn_drop(hcon);
+		err = -EBUSY;
+		goto chan_unlock;
+	}
+
+	/* Update source addr of the socket */
+	bacpy(&chan->src, &hcon->src);
+	chan->src_type = bdaddr_src_type(hcon);
+
+	__l2cap_chan_add(conn, chan);
+
+	/* l2cap_chan_add takes its own ref so we can drop this one */
+	hci_conn_drop(hcon);
+
+	l2cap_state_change(chan, BT_CONNECT);
+	__set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
+
+	/* Release chan->sport so that it can be reused by other
+	 * sockets (as it's only used for listening sockets).
+	 */
+	write_lock(&chan_list_lock);
+	chan->sport = 0;
+	write_unlock(&chan_list_lock);
+
+	if (hcon->state == BT_CONNECTED) {
+		if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
+			__clear_chan_timer(chan);
+			if (l2cap_chan_check_security(chan, true))
+				l2cap_state_change(chan, BT_CONNECTED);
+		} else
+			l2cap_do_start(chan);
+	}
+
+	err = 0;
+
+chan_unlock:
+	l2cap_chan_unlock(chan);
+	mutex_unlock(&conn->chan_lock);
+done:
+	hci_dev_unlock(hdev);
+	hci_dev_put(hdev);
+	return err;
+}
+EXPORT_SYMBOL_GPL(l2cap_chan_connect);
+
+static void l2cap_ecred_reconfigure(struct l2cap_chan *chan)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct {
+		struct l2cap_ecred_reconf_req req;
+		__le16 scid;
+	} pdu;
+
+	pdu.req.mtu = cpu_to_le16(chan->imtu);
+	pdu.req.mps = cpu_to_le16(chan->mps);
+	pdu.scid    = cpu_to_le16(chan->scid);
+
+	chan->ident = l2cap_get_ident(conn);
+
+	l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ,
+		       sizeof(pdu), &pdu);
+}
+
+int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu)
+{
+	if (chan->imtu > mtu)
+		return -EINVAL;
+
+	BT_DBG("chan %p mtu 0x%4.4x", chan, mtu);
+
+	chan->imtu = mtu;
+
+	l2cap_ecred_reconfigure(chan);
+
+	return 0;
+}
+
+/* ---- L2CAP interface with lower layer (HCI) ---- */
+
+int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr)
+{
+	int exact = 0, lm1 = 0, lm2 = 0;
+	struct l2cap_chan *c;
+
+	BT_DBG("hdev %s, bdaddr %pMR", hdev->name, bdaddr);
+
+	/* Find listening sockets and check their link_mode */
+	read_lock(&chan_list_lock);
+	list_for_each_entry(c, &chan_list, global_l) {
+		if (c->state != BT_LISTEN)
+			continue;
+
+		if (!bacmp(&c->src, &hdev->bdaddr)) {
+			lm1 |= HCI_LM_ACCEPT;
+			if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
+				lm1 |= HCI_LM_MASTER;
+			exact++;
+		} else if (!bacmp(&c->src, BDADDR_ANY)) {
+			lm2 |= HCI_LM_ACCEPT;
+			if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
+				lm2 |= HCI_LM_MASTER;
+		}
+	}
+	read_unlock(&chan_list_lock);
+
+	return exact ? lm1 : lm2;
+}
+
+/* Find the next fixed channel in BT_LISTEN state, continue iteration
+ * from an existing channel in the list or from the beginning of the
+ * global list (by passing NULL as first parameter).
+ */
+static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c,
+						  struct hci_conn *hcon)
+{
+	u8 src_type = bdaddr_src_type(hcon);
+
+	read_lock(&chan_list_lock);
+
+	if (c)
+		c = list_next_entry(c, global_l);
+	else
+		c = list_entry(chan_list.next, typeof(*c), global_l);
+
+	list_for_each_entry_from(c, &chan_list, global_l) {
+		if (c->chan_type != L2CAP_CHAN_FIXED)
+			continue;
+		if (c->state != BT_LISTEN)
+			continue;
+		if (bacmp(&c->src, &hcon->src) && bacmp(&c->src, BDADDR_ANY))
+			continue;
+		if (src_type != c->src_type)
+			continue;
+
+		c = l2cap_chan_hold_unless_zero(c);
+		read_unlock(&chan_list_lock);
+		return c;
+	}
+
+	read_unlock(&chan_list_lock);
+
+	return NULL;
+}
+
+static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status)
+{
+	struct hci_dev *hdev = hcon->hdev;
+	struct l2cap_conn *conn;
+	struct l2cap_chan *pchan;
+	u8 dst_type;
+
+	if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
+		return;
+
+	BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status);
+
+	if (status) {
+		l2cap_conn_del(hcon, bt_to_errno(status));
+		return;
+	}
+
+	conn = l2cap_conn_add(hcon);
+	if (!conn)
+		return;
+
+	dst_type = bdaddr_dst_type(hcon);
+
+	/* If device is blocked, do not create channels for it */
+	if (hci_bdaddr_list_lookup(&hdev->reject_list, &hcon->dst, dst_type))
+		return;
+
+	/* Find fixed channels and notify them of the new connection. We
+	 * use multiple individual lookups, continuing each time where
+	 * we left off, because the list lock would prevent calling the
+	 * potentially sleeping l2cap_chan_lock() function.
+	 */
+	pchan = l2cap_global_fixed_chan(NULL, hcon);
+	while (pchan) {
+		struct l2cap_chan *chan, *next;
+
+		/* Client fixed channels should override server ones */
+		if (__l2cap_get_chan_by_dcid(conn, pchan->scid))
+			goto next;
+
+		l2cap_chan_lock(pchan);
+		chan = pchan->ops->new_connection(pchan);
+		if (chan) {
+			bacpy(&chan->src, &hcon->src);
+			bacpy(&chan->dst, &hcon->dst);
+			chan->src_type = bdaddr_src_type(hcon);
+			chan->dst_type = dst_type;
+
+			__l2cap_chan_add(conn, chan);
+		}
+
+		l2cap_chan_unlock(pchan);
+next:
+		next = l2cap_global_fixed_chan(pchan, hcon);
+		l2cap_chan_put(pchan);
+		pchan = next;
+	}
+
+	l2cap_conn_ready(conn);
+}
+
+int l2cap_disconn_ind(struct hci_conn *hcon)
+{
+	struct l2cap_conn *conn = hcon->l2cap_data;
+
+	BT_DBG("hcon %p", hcon);
+
+	if (!conn)
+		return HCI_ERROR_REMOTE_USER_TERM;
+	return conn->disc_reason;
+}
+
+static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason)
+{
+	if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
+		return;
+
+	BT_DBG("hcon %p reason %d", hcon, reason);
+
+	l2cap_conn_del(hcon, bt_to_errno(reason));
+}
+
+static inline void l2cap_check_encryption(struct l2cap_chan *chan, u8 encrypt)
+{
+	if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
+		return;
+
+	if (encrypt == 0x00) {
+		if (chan->sec_level == BT_SECURITY_MEDIUM) {
+			__set_chan_timer(chan, L2CAP_ENC_TIMEOUT);
+		} else if (chan->sec_level == BT_SECURITY_HIGH ||
+			   chan->sec_level == BT_SECURITY_FIPS)
+			l2cap_chan_close(chan, ECONNREFUSED);
+	} else {
+		if (chan->sec_level == BT_SECURITY_MEDIUM)
+			__clear_chan_timer(chan);
+	}
+}
+
+static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
+{
+	struct l2cap_conn *conn = hcon->l2cap_data;
+	struct l2cap_chan *chan;
+
+	if (!conn)
+		return;
+
+	BT_DBG("conn %p status 0x%2.2x encrypt %u", conn, status, encrypt);
+
+	mutex_lock(&conn->chan_lock);
+
+	list_for_each_entry(chan, &conn->chan_l, list) {
+		l2cap_chan_lock(chan);
+
+		BT_DBG("chan %p scid 0x%4.4x state %s", chan, chan->scid,
+		       state_to_string(chan->state));
+
+		if (chan->scid == L2CAP_CID_A2MP) {
+			l2cap_chan_unlock(chan);
+			continue;
+		}
+
+		if (!status && encrypt)
+			chan->sec_level = hcon->sec_level;
+
+		if (!__l2cap_no_conn_pending(chan)) {
+			l2cap_chan_unlock(chan);
+			continue;
+		}
+
+		if (!status && (chan->state == BT_CONNECTED ||
+				chan->state == BT_CONFIG)) {
+			chan->ops->resume(chan);
+			l2cap_check_encryption(chan, encrypt);
+			l2cap_chan_unlock(chan);
+			continue;
+		}
+
+		if (chan->state == BT_CONNECT) {
+			if (!status && l2cap_check_enc_key_size(hcon))
+				l2cap_start_connection(chan);
+			else
+				__set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
+		} else if (chan->state == BT_CONNECT2 &&
+			   !(chan->mode == L2CAP_MODE_EXT_FLOWCTL ||
+			     chan->mode == L2CAP_MODE_LE_FLOWCTL)) {
+			struct l2cap_conn_rsp rsp;
+			__u16 res, stat;
+
+			if (!status && l2cap_check_enc_key_size(hcon)) {
+				if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
+					res = L2CAP_CR_PEND;
+					stat = L2CAP_CS_AUTHOR_PEND;
+					chan->ops->defer(chan);
+				} else {
+					l2cap_state_change(chan, BT_CONFIG);
+					res = L2CAP_CR_SUCCESS;
+					stat = L2CAP_CS_NO_INFO;
+				}
+			} else {
+				l2cap_state_change(chan, BT_DISCONN);
+				__set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
+				res = L2CAP_CR_SEC_BLOCK;
+				stat = L2CAP_CS_NO_INFO;
+			}
+
+			rsp.scid   = cpu_to_le16(chan->dcid);
+			rsp.dcid   = cpu_to_le16(chan->scid);
+			rsp.result = cpu_to_le16(res);
+			rsp.status = cpu_to_le16(stat);
+			l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
+				       sizeof(rsp), &rsp);
+
+			if (!test_bit(CONF_REQ_SENT, &chan->conf_state) &&
+			    res == L2CAP_CR_SUCCESS) {
+				char buf[128];
+				set_bit(CONF_REQ_SENT, &chan->conf_state);
+				l2cap_send_cmd(conn, l2cap_get_ident(conn),
+					       L2CAP_CONF_REQ,
+					       l2cap_build_conf_req(chan, buf, sizeof(buf)),
+					       buf);
+				chan->num_conf_req++;
+			}
+		}
+
+		l2cap_chan_unlock(chan);
+	}
+
+	mutex_unlock(&conn->chan_lock);
+}
+
+/* Append fragment into frame respecting the maximum len of rx_skb */
+static int l2cap_recv_frag(struct l2cap_conn *conn, struct sk_buff *skb,
+			   u16 len)
+{
+	if (!conn->rx_skb) {
+		/* Allocate skb for the complete frame (with header) */
+		conn->rx_skb = bt_skb_alloc(len, GFP_KERNEL);
+		if (!conn->rx_skb)
+			return -ENOMEM;
+		/* Init rx_len */
+		conn->rx_len = len;
+	}
+
+	/* Copy as much as the rx_skb can hold */
+	len = min_t(u16, len, skb->len);
+	skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, len), len);
+	skb_pull(skb, len);
+	conn->rx_len -= len;
+
+	return len;
+}
+
+static int l2cap_recv_len(struct l2cap_conn *conn, struct sk_buff *skb)
+{
+	struct sk_buff *rx_skb;
+	int len;
+
+	/* Append just enough to complete the header */
+	len = l2cap_recv_frag(conn, skb, L2CAP_LEN_SIZE - conn->rx_skb->len);
+
+	/* If header could not be read just continue */
+	if (len < 0 || conn->rx_skb->len < L2CAP_LEN_SIZE)
+		return len;
+
+	rx_skb = conn->rx_skb;
+	len = get_unaligned_le16(rx_skb->data);
+
+	/* Check if rx_skb has enough space to received all fragments */
+	if (len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE) <= skb_tailroom(rx_skb)) {
+		/* Update expected len */
+		conn->rx_len = len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE);
+		return L2CAP_LEN_SIZE;
+	}
+
+	/* Reset conn->rx_skb since it will need to be reallocated in order to
+	 * fit all fragments.
+	 */
+	conn->rx_skb = NULL;
+
+	/* Reallocates rx_skb using the exact expected length */
+	len = l2cap_recv_frag(conn, rx_skb,
+			      len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE));
+	kfree_skb(rx_skb);
+
+	return len;
+}
+
+static void l2cap_recv_reset(struct l2cap_conn *conn)
+{
+	kfree_skb(conn->rx_skb);
+	conn->rx_skb = NULL;
+	conn->rx_len = 0;
+}
+
+void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
+{
+	struct l2cap_conn *conn = hcon->l2cap_data;
+	int len;
+
+	/* For AMP controller do not create l2cap conn */
+	if (!conn && hcon->hdev->dev_type != HCI_PRIMARY)
+		goto drop;
+
+	if (!conn)
+		conn = l2cap_conn_add(hcon);
+
+	if (!conn)
+		goto drop;
+
+	BT_DBG("conn %p len %u flags 0x%x", conn, skb->len, flags);
+
+	switch (flags) {
+	case ACL_START:
+	case ACL_START_NO_FLUSH:
+	case ACL_COMPLETE:
+		if (conn->rx_skb) {
+			BT_ERR("Unexpected start frame (len %d)", skb->len);
+			l2cap_recv_reset(conn);
+			l2cap_conn_unreliable(conn, ECOMM);
+		}
+
+		/* Start fragment may not contain the L2CAP length so just
+		 * copy the initial byte when that happens and use conn->mtu as
+		 * expected length.
+		 */
+		if (skb->len < L2CAP_LEN_SIZE) {
+			l2cap_recv_frag(conn, skb, conn->mtu);
+			break;
+		}
+
+		len = get_unaligned_le16(skb->data) + L2CAP_HDR_SIZE;
+
+		if (len == skb->len) {
+			/* Complete frame received */
+			l2cap_recv_frame(conn, skb);
+			return;
+		}
+
+		BT_DBG("Start: total len %d, frag len %u", len, skb->len);
+
+		if (skb->len > len) {
+			BT_ERR("Frame is too long (len %u, expected len %d)",
+			       skb->len, len);
+			l2cap_conn_unreliable(conn, ECOMM);
+			goto drop;
+		}
+
+		/* Append fragment into frame (with header) */
+		if (l2cap_recv_frag(conn, skb, len) < 0)
+			goto drop;
+
+		break;
+
+	case ACL_CONT:
+		BT_DBG("Cont: frag len %u (expecting %u)", skb->len, conn->rx_len);
+
+		if (!conn->rx_skb) {
+			BT_ERR("Unexpected continuation frame (len %d)", skb->len);
+			l2cap_conn_unreliable(conn, ECOMM);
+			goto drop;
+		}
+
+		/* Complete the L2CAP length if it has not been read */
+		if (conn->rx_skb->len < L2CAP_LEN_SIZE) {
+			if (l2cap_recv_len(conn, skb) < 0) {
+				l2cap_conn_unreliable(conn, ECOMM);
+				goto drop;
+			}
+
+			/* Header still could not be read just continue */
+			if (conn->rx_skb->len < L2CAP_LEN_SIZE)
+				break;
+		}
+
+		if (skb->len > conn->rx_len) {
+			BT_ERR("Fragment is too long (len %u, expected %u)",
+			       skb->len, conn->rx_len);
+			l2cap_recv_reset(conn);
+			l2cap_conn_unreliable(conn, ECOMM);
+			goto drop;
+		}
+
+		/* Append fragment into frame (with header) */
+		l2cap_recv_frag(conn, skb, skb->len);
+
+		if (!conn->rx_len) {
+			/* Complete frame received. l2cap_recv_frame
+			 * takes ownership of the skb so set the global
+			 * rx_skb pointer to NULL first.
+			 */
+			struct sk_buff *rx_skb = conn->rx_skb;
+			conn->rx_skb = NULL;
+			l2cap_recv_frame(conn, rx_skb);
+		}
+		break;
+	}
+
+drop:
+	kfree_skb(skb);
+}
+
+static struct hci_cb l2cap_cb = {
+	.name		= "L2CAP",
+	.connect_cfm	= l2cap_connect_cfm,
+	.disconn_cfm	= l2cap_disconn_cfm,
+	.security_cfm	= l2cap_security_cfm,
+};
+
+static int l2cap_debugfs_show(struct seq_file *f, void *p)
+{
+	struct l2cap_chan *c;
+
+	read_lock(&chan_list_lock);
+
+	list_for_each_entry(c, &chan_list, global_l) {
+		seq_printf(f, "%pMR (%u) %pMR (%u) %d %d 0x%4.4x 0x%4.4x %d %d %d %d\n",
+			   &c->src, c->src_type, &c->dst, c->dst_type,
+			   c->state, __le16_to_cpu(c->psm),
+			   c->scid, c->dcid, c->imtu, c->omtu,
+			   c->sec_level, c->mode);
+	}
+
+	read_unlock(&chan_list_lock);
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(l2cap_debugfs);
+
+static struct dentry *l2cap_debugfs;
+
+int __init l2cap_init(void)
+{
+	int err;
+
+	err = l2cap_init_sockets();
+	if (err < 0)
+		return err;
+
+	hci_register_cb(&l2cap_cb);
+
+	if (IS_ERR_OR_NULL(bt_debugfs))
+		return 0;
+
+	l2cap_debugfs = debugfs_create_file("l2cap", 0444, bt_debugfs,
+					    NULL, &l2cap_debugfs_fops);
+
+	return 0;
+}
+
+void l2cap_exit(void)
+{
+	debugfs_remove(l2cap_debugfs);
+	hci_unregister_cb(&l2cap_cb);
+	l2cap_cleanup_sockets();
+}
+
+module_param(disable_ertm, bool, 0644);
+MODULE_PARM_DESC(disable_ertm, "Disable enhanced retransmission mode");
+
+module_param(enable_ecred, bool, 0644);
+MODULE_PARM_DESC(enable_ecred, "Enable enhanced credit flow control mode");