net/bluetooth/amp.c - kernel/msm-4.9 - Gitiles

 /*
    Copyright (c) 2011,2012 Intel Corp.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License version 2 and
    only version 2 as published by the Free Software Foundation.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 */

 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci.h>
 #include <net/bluetooth/hci_core.h>
 #include <crypto/hash.h>

 #include "hci_request.h"
 #include "a2mp.h"
 #include "amp.h"

 /* Remote AMP Controllers interface */
 void amp_ctrl_get(struct amp_ctrl *ctrl)
 {
 	BT_DBG("ctrl %p orig refcnt %d", ctrl,
 	       atomic_read(&ctrl->kref.refcount));

 	kref_get(&ctrl->kref);
 }

 static void amp_ctrl_destroy(struct kref *kref)
 {
 	struct amp_ctrl *ctrl = container_of(kref, struct amp_ctrl, kref);

 	BT_DBG("ctrl %p", ctrl);

 	kfree(ctrl->assoc);
 	kfree(ctrl);
 }

 int amp_ctrl_put(struct amp_ctrl *ctrl)
 {
 	BT_DBG("ctrl %p orig refcnt %d", ctrl,
 	       atomic_read(&ctrl->kref.refcount));

 	return kref_put(&ctrl->kref, &amp_ctrl_destroy);
 }

 struct amp_ctrl *amp_ctrl_add(struct amp_mgr *mgr, u8 id)
 {
 	struct amp_ctrl *ctrl;

 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 	if (!ctrl)
 		return NULL;

 	kref_init(&ctrl->kref);
 	ctrl->id = id;

 	mutex_lock(&mgr->amp_ctrls_lock);
 	list_add(&ctrl->list, &mgr->amp_ctrls);
 	mutex_unlock(&mgr->amp_ctrls_lock);

 	BT_DBG("mgr %p ctrl %p", mgr, ctrl);

 	return ctrl;
 }

 void amp_ctrl_list_flush(struct amp_mgr *mgr)
 {
 	struct amp_ctrl *ctrl, *n;

 	BT_DBG("mgr %p", mgr);

 	mutex_lock(&mgr->amp_ctrls_lock);
 	list_for_each_entry_safe(ctrl, n, &mgr->amp_ctrls, list) {
 		list_del(&ctrl->list);
 		amp_ctrl_put(ctrl);
 	}
 	mutex_unlock(&mgr->amp_ctrls_lock);
 }

 struct amp_ctrl *amp_ctrl_lookup(struct amp_mgr *mgr, u8 id)
 {
 	struct amp_ctrl *ctrl;

 	BT_DBG("mgr %p id %d", mgr, id);

 	mutex_lock(&mgr->amp_ctrls_lock);
 	list_for_each_entry(ctrl, &mgr->amp_ctrls, list) {
 		if (ctrl->id == id) {
 			amp_ctrl_get(ctrl);
 			mutex_unlock(&mgr->amp_ctrls_lock);
 			return ctrl;
 		}
 	}
 	mutex_unlock(&mgr->amp_ctrls_lock);

 	return NULL;
 }

 /* Physical Link interface */
 static u8 __next_handle(struct amp_mgr *mgr)
 {
 	if (++mgr->handle == 0)
 		mgr->handle = 1;

 	return mgr->handle;
 }

 struct hci_conn *phylink_add(struct hci_dev *hdev, struct amp_mgr *mgr,
 			     u8 remote_id, bool out)
 {
 	bdaddr_t *dst = &mgr->l2cap_conn->hcon->dst;
 	struct hci_conn *hcon;
 	u8 role = out ? HCI_ROLE_MASTER : HCI_ROLE_SLAVE;

 	hcon = hci_conn_add(hdev, AMP_LINK, dst, role);
 	if (!hcon)
 		return NULL;

 	BT_DBG("hcon %p dst %pMR", hcon, dst);

 	hcon->state = BT_CONNECT;
 	hcon->attempt++;
 	hcon->handle = __next_handle(mgr);
 	hcon->remote_id = remote_id;
 	hcon->amp_mgr = amp_mgr_get(mgr);

 	return hcon;
 }

 /* AMP crypto key generation interface */
 static int hmac_sha256(u8 *key, u8 ksize, char *plaintext, u8 psize, u8 *output)
 {
 	struct crypto_shash *tfm;
 	struct shash_desc *shash;
 	int ret;

 	if (!ksize)
 		return -EINVAL;

 	tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
 	if (IS_ERR(tfm)) {
 		BT_DBG("crypto_alloc_ahash failed: err %ld", PTR_ERR(tfm));
 		return PTR_ERR(tfm);
 	}

 	ret = crypto_shash_setkey(tfm, key, ksize);
 	if (ret) {
 		BT_DBG("crypto_ahash_setkey failed: err %d", ret);
 		goto failed;
 	}

 	shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(tfm),
 			GFP_KERNEL);
 	if (!shash) {
 		ret = -ENOMEM;
 		goto failed;
 	}

 	shash->tfm = tfm;
 	shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP;

 	ret = crypto_shash_digest(shash, plaintext, psize, output);

 	kfree(shash);

 failed:
 	crypto_free_shash(tfm);
 	return ret;
 }

 int phylink_gen_key(struct hci_conn *conn, u8 *data, u8 *len, u8 *type)
 {
 	struct hci_dev *hdev = conn->hdev;
 	struct link_key *key;
 	u8 keybuf[HCI_AMP_LINK_KEY_SIZE];
 	u8 gamp_key[HCI_AMP_LINK_KEY_SIZE];
 	int err;

 	if (!hci_conn_check_link_mode(conn))
 		return -EACCES;

 	BT_DBG("conn %p key_type %d", conn, conn->key_type);

 	/* Legacy key */
 	if (conn->key_type < 3) {
 		BT_ERR("Legacy key type %d", conn->key_type);
 		return -EACCES;
 	}

 	*type = conn->key_type;
 	*len = HCI_AMP_LINK_KEY_SIZE;

 	key = hci_find_link_key(hdev, &conn->dst);
 	if (!key) {
 		BT_DBG("No Link key for conn %p dst %pMR", conn, &conn->dst);
 		return -EACCES;
 	}

 	/* BR/EDR Link Key concatenated together with itself */
 	memcpy(&keybuf[0], key->val, HCI_LINK_KEY_SIZE);
 	memcpy(&keybuf[HCI_LINK_KEY_SIZE], key->val, HCI_LINK_KEY_SIZE);

 	/* Derive Generic AMP Link Key (gamp) */
 	err = hmac_sha256(keybuf, HCI_AMP_LINK_KEY_SIZE, "gamp", 4, gamp_key);
 	if (err) {
 		BT_ERR("Could not derive Generic AMP Key: err %d", err);
 		return err;
 	}

 	if (conn->key_type == HCI_LK_DEBUG_COMBINATION) {
 		BT_DBG("Use Generic AMP Key (gamp)");
 		memcpy(data, gamp_key, HCI_AMP_LINK_KEY_SIZE);
 		return err;
 	}

 	/* Derive Dedicated AMP Link Key: "802b" is 802.11 PAL keyID */
 	return hmac_sha256(gamp_key, HCI_AMP_LINK_KEY_SIZE, "802b", 4, data);
 }

 static void read_local_amp_assoc_complete(struct hci_dev *hdev, u8 status,
 					  u16 opcode, struct sk_buff *skb)
 {
 	struct hci_rp_read_local_amp_assoc *rp = (void *)skb->data;
 	struct amp_assoc *assoc = &hdev->loc_assoc;
 	size_t rem_len, frag_len;

 	BT_DBG("%s status 0x%2.2x", hdev->name, rp->status);

 	if (rp->status)
 		goto send_rsp;

 	frag_len = skb->len - sizeof(*rp);
 	rem_len = __le16_to_cpu(rp->rem_len);

 	if (rem_len > frag_len) {
 		BT_DBG("frag_len %zu rem_len %zu", frag_len, rem_len);

 		memcpy(assoc->data + assoc->offset, rp->frag, frag_len);
 		assoc->offset += frag_len;

 		/* Read other fragments */
 		amp_read_loc_assoc_frag(hdev, rp->phy_handle);

 		return;
 	}

 	memcpy(assoc->data + assoc->offset, rp->frag, rem_len);
 	assoc->len = assoc->offset + rem_len;
 	assoc->offset = 0;

 send_rsp:
 	/* Send A2MP Rsp when all fragments are received */
 	a2mp_send_getampassoc_rsp(hdev, rp->status);
 	a2mp_send_create_phy_link_req(hdev, rp->status);
 }

 void amp_read_loc_assoc_frag(struct hci_dev *hdev, u8 phy_handle)
 {
 	struct hci_cp_read_local_amp_assoc cp;
 	struct amp_assoc *loc_assoc = &hdev->loc_assoc;
 	struct hci_request req;
 	int err = 0;

 	BT_DBG("%s handle %d", hdev->name, phy_handle);

 	cp.phy_handle = phy_handle;
 	cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
 	cp.len_so_far = cpu_to_le16(loc_assoc->offset);

 	hci_req_init(&req, hdev);
 	hci_req_add(&req, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
 	err = hci_req_run_skb(&req, read_local_amp_assoc_complete);
 	if (err < 0)
 		a2mp_send_getampassoc_rsp(hdev, A2MP_STATUS_INVALID_CTRL_ID);
 }

 void amp_read_loc_assoc(struct hci_dev *hdev, struct amp_mgr *mgr)
 {
 	struct hci_cp_read_local_amp_assoc cp;
 	struct hci_request req;
 	int err = 0;

 	memset(&hdev->loc_assoc, 0, sizeof(struct amp_assoc));
 	memset(&cp, 0, sizeof(cp));

 	cp.max_len = cpu_to_le16(hdev->amp_assoc_size);

 	set_bit(READ_LOC_AMP_ASSOC, &mgr->state);
 	hci_req_init(&req, hdev);
 	hci_req_add(&req, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
 	hci_req_run_skb(&req, read_local_amp_assoc_complete);
 	if (err < 0)
 		a2mp_send_getampassoc_rsp(hdev, A2MP_STATUS_INVALID_CTRL_ID);
 }

 void amp_read_loc_assoc_final_data(struct hci_dev *hdev,
 				   struct hci_conn *hcon)
 {
 	struct hci_cp_read_local_amp_assoc cp;
 	struct amp_mgr *mgr = hcon->amp_mgr;
 	struct hci_request req;
 	int err = 0;

 	cp.phy_handle = hcon->handle;
 	cp.len_so_far = cpu_to_le16(0);
 	cp.max_len = cpu_to_le16(hdev->amp_assoc_size);

 	set_bit(READ_LOC_AMP_ASSOC_FINAL, &mgr->state);

 	/* Read Local AMP Assoc final link information data */
 	hci_req_init(&req, hdev);
 	hci_req_add(&req, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
 	hci_req_run_skb(&req, read_local_amp_assoc_complete);
 	if (err < 0)
 		a2mp_send_getampassoc_rsp(hdev, A2MP_STATUS_INVALID_CTRL_ID);
 }

 static void write_remote_amp_assoc_complete(struct hci_dev *hdev, u8 status,
 					    u16 opcode, struct sk_buff *skb)
 {
 	struct hci_rp_write_remote_amp_assoc *rp = (void *)skb->data;

 	BT_DBG("%s status 0x%2.2x phy_handle 0x%2.2x",
 	       hdev->name, rp->status, rp->phy_handle);

 	if (rp->status)
 		return;

 	amp_write_rem_assoc_continue(hdev, rp->phy_handle);
 }

 /* Write AMP Assoc data fragments, returns true with last fragment written*/
 static bool amp_write_rem_assoc_frag(struct hci_dev *hdev,
 				     struct hci_conn *hcon)
 {
 	struct hci_cp_write_remote_amp_assoc *cp;
 	struct amp_mgr *mgr = hcon->amp_mgr;
 	struct amp_ctrl *ctrl;
 	struct hci_request req;
 	u16 frag_len, len;

 	ctrl = amp_ctrl_lookup(mgr, hcon->remote_id);
 	if (!ctrl)
 		return false;

 	if (!ctrl->assoc_rem_len) {
 		BT_DBG("all fragments are written");
 		ctrl->assoc_rem_len = ctrl->assoc_len;
 		ctrl->assoc_len_so_far = 0;

 		amp_ctrl_put(ctrl);
 		return true;
 	}

 	frag_len = min_t(u16, 248, ctrl->assoc_rem_len);
 	len = frag_len + sizeof(*cp);

 	cp = kzalloc(len, GFP_KERNEL);
 	if (!cp) {
 		amp_ctrl_put(ctrl);
 		return false;
 	}

 	BT_DBG("hcon %p ctrl %p frag_len %u assoc_len %u rem_len %u",
 	       hcon, ctrl, frag_len, ctrl->assoc_len, ctrl->assoc_rem_len);

 	cp->phy_handle = hcon->handle;
 	cp->len_so_far = cpu_to_le16(ctrl->assoc_len_so_far);
 	cp->rem_len = cpu_to_le16(ctrl->assoc_rem_len);
 	memcpy(cp->frag, ctrl->assoc, frag_len);

 	ctrl->assoc_len_so_far += frag_len;
 	ctrl->assoc_rem_len -= frag_len;

 	amp_ctrl_put(ctrl);

 	hci_req_init(&req, hdev);
 	hci_req_add(&req, HCI_OP_WRITE_REMOTE_AMP_ASSOC, sizeof(cp), &cp);
 	hci_req_run_skb(&req, write_remote_amp_assoc_complete);

 	kfree(cp);

 	return false;
 }

 void amp_write_rem_assoc_continue(struct hci_dev *hdev, u8 handle)
 {
 	struct hci_conn *hcon;

 	BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);

 	hcon = hci_conn_hash_lookup_handle(hdev, handle);
 	if (!hcon)
 		return;

 	/* Send A2MP create phylink rsp when all fragments are written */
 	if (amp_write_rem_assoc_frag(hdev, hcon))
 		a2mp_send_create_phy_link_rsp(hdev, 0);
 }

 void amp_write_remote_assoc(struct hci_dev *hdev, u8 handle)
 {
 	struct hci_conn *hcon;

 	BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);

 	hcon = hci_conn_hash_lookup_handle(hdev, handle);
 	if (!hcon)
 		return;

 	BT_DBG("%s phy handle 0x%2.2x hcon %p", hdev->name, handle, hcon);

 	amp_write_rem_assoc_frag(hdev, hcon);
 }

 static void create_phylink_complete(struct hci_dev *hdev, u8 status,
 				    u16 opcode)
 {
 	struct hci_cp_create_phy_link *cp;

 	BT_DBG("%s status 0x%2.2x", hdev->name, status);

 	cp = hci_sent_cmd_data(hdev, HCI_OP_CREATE_PHY_LINK);
 	if (!cp)
 		return;

 	hci_dev_lock(hdev);

 	if (status) {
 		struct hci_conn *hcon;

 		hcon = hci_conn_hash_lookup_handle(hdev, cp->phy_handle);
 		if (hcon)
 			hci_conn_del(hcon);
 	} else {
 		amp_write_remote_assoc(hdev, cp->phy_handle);
 	}

 	hci_dev_unlock(hdev);
 }

 void amp_create_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
 			struct hci_conn *hcon)
 {
 	struct hci_cp_create_phy_link cp;
 	struct hci_request req;

 	cp.phy_handle = hcon->handle;

 	BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
 	       hcon->handle);

 	if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
 			    &cp.key_type)) {
 		BT_DBG("Cannot create link key");
 		return;
 	}

 	hci_req_init(&req, hdev);
 	hci_req_add(&req, HCI_OP_CREATE_PHY_LINK, sizeof(cp), &cp);
 	hci_req_run(&req, create_phylink_complete);
 }

 static void accept_phylink_complete(struct hci_dev *hdev, u8 status,
 				    u16 opcode)
 {
 	struct hci_cp_accept_phy_link *cp;

 	BT_DBG("%s status 0x%2.2x", hdev->name, status);

 	if (status)
 		return;

 	cp = hci_sent_cmd_data(hdev, HCI_OP_ACCEPT_PHY_LINK);
 	if (!cp)
 		return;

 	amp_write_remote_assoc(hdev, cp->phy_handle);
 }

 void amp_accept_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
 			struct hci_conn *hcon)
 {
 	struct hci_cp_accept_phy_link cp;
 	struct hci_request req;

 	cp.phy_handle = hcon->handle;

 	BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
 	       hcon->handle);

 	if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
 			    &cp.key_type)) {
 		BT_DBG("Cannot create link key");
 		return;
 	}

 	hci_req_init(&req, hdev);
 	hci_req_add(&req, HCI_OP_ACCEPT_PHY_LINK, sizeof(cp), &cp);
 	hci_req_run(&req, accept_phylink_complete);
 }

 void amp_physical_cfm(struct hci_conn *bredr_hcon, struct hci_conn *hs_hcon)
 {
 	struct hci_dev *bredr_hdev = hci_dev_hold(bredr_hcon->hdev);
 	struct amp_mgr *mgr = hs_hcon->amp_mgr;
 	struct l2cap_chan *bredr_chan;

 	BT_DBG("bredr_hcon %p hs_hcon %p mgr %p", bredr_hcon, hs_hcon, mgr);

 	if (!bredr_hdev || !mgr || !mgr->bredr_chan)
 		return;

 	bredr_chan = mgr->bredr_chan;

 	l2cap_chan_lock(bredr_chan);

 	set_bit(FLAG_EFS_ENABLE, &bredr_chan->flags);
 	bredr_chan->remote_amp_id = hs_hcon->remote_id;
 	bredr_chan->local_amp_id = hs_hcon->hdev->id;
 	bredr_chan->hs_hcon = hs_hcon;
 	bredr_chan->conn->mtu = hs_hcon->hdev->block_mtu;

 	__l2cap_physical_cfm(bredr_chan, 0);

 	l2cap_chan_unlock(bredr_chan);

 	hci_dev_put(bredr_hdev);
 }

 void amp_create_logical_link(struct l2cap_chan *chan)
 {
 	struct hci_conn *hs_hcon = chan->hs_hcon;
 	struct hci_cp_create_accept_logical_link cp;
 	struct hci_dev *hdev;

 	BT_DBG("chan %p hs_hcon %p dst %pMR", chan, hs_hcon,
 	       &chan->conn->hcon->dst);

 	if (!hs_hcon)
 		return;

 	hdev = hci_dev_hold(chan->hs_hcon->hdev);
 	if (!hdev)
 		return;

 	cp.phy_handle = hs_hcon->handle;

 	cp.tx_flow_spec.id = chan->local_id;
 	cp.tx_flow_spec.stype = chan->local_stype;
 	cp.tx_flow_spec.msdu = cpu_to_le16(chan->local_msdu);
 	cp.tx_flow_spec.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
 	cp.tx_flow_spec.acc_lat = cpu_to_le32(chan->local_acc_lat);
 	cp.tx_flow_spec.flush_to = cpu_to_le32(chan->local_flush_to);

 	cp.rx_flow_spec.id = chan->remote_id;
 	cp.rx_flow_spec.stype = chan->remote_stype;
 	cp.rx_flow_spec.msdu = cpu_to_le16(chan->remote_msdu);
 	cp.rx_flow_spec.sdu_itime = cpu_to_le32(chan->remote_sdu_itime);
 	cp.rx_flow_spec.acc_lat = cpu_to_le32(chan->remote_acc_lat);
 	cp.rx_flow_spec.flush_to = cpu_to_le32(chan->remote_flush_to);

 	if (hs_hcon->out)
 		hci_send_cmd(hdev, HCI_OP_CREATE_LOGICAL_LINK, sizeof(cp),
 			     &cp);
 	else
 		hci_send_cmd(hdev, HCI_OP_ACCEPT_LOGICAL_LINK, sizeof(cp),
 			     &cp);

 	hci_dev_put(hdev);
 }

 void amp_disconnect_logical_link(struct hci_chan *hchan)
 {
 	struct hci_conn *hcon = hchan->conn;
 	struct hci_cp_disconn_logical_link cp;

 	if (hcon->state != BT_CONNECTED) {
 		BT_DBG("hchan %p not connected", hchan);
 		return;
 	}

 	cp.log_handle = cpu_to_le16(hchan->handle);
 	hci_send_cmd(hcon->hdev, HCI_OP_DISCONN_LOGICAL_LINK, sizeof(cp), &cp);
 }

 void amp_destroy_logical_link(struct hci_chan *hchan, u8 reason)
 {
 	BT_DBG("hchan %p", hchan);

 	hci_chan_del(hchan);
 }
	/*
	Copyright (c) 2011,2012 Intel Corp.

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License version 2 and
	only version 2 as published by the Free Software Foundation.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.
	*/

	#include <net/bluetooth/bluetooth.h>
	#include <net/bluetooth/hci.h>
	#include <net/bluetooth/hci_core.h>
	#include <crypto/hash.h>

	#include "hci_request.h"
	#include "a2mp.h"
	#include "amp.h"

	/* Remote AMP Controllers interface */
	void amp_ctrl_get(struct amp_ctrl *ctrl)
	{
	BT_DBG("ctrl %p orig refcnt %d", ctrl,
	atomic_read(&ctrl->kref.refcount));

	kref_get(&ctrl->kref);
	}

	static void amp_ctrl_destroy(struct kref *kref)
	{
	struct amp_ctrl *ctrl = container_of(kref, struct amp_ctrl, kref);

	BT_DBG("ctrl %p", ctrl);

	kfree(ctrl->assoc);
	kfree(ctrl);
	}

	int amp_ctrl_put(struct amp_ctrl *ctrl)
	{
	BT_DBG("ctrl %p orig refcnt %d", ctrl,
	atomic_read(&ctrl->kref.refcount));

	return kref_put(&ctrl->kref, &amp_ctrl_destroy);
	}

	struct amp_ctrl amp_ctrl_add(struct amp_mgr mgr, u8 id)
	{
	struct amp_ctrl *ctrl;

	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
	if (!ctrl)
	return NULL;

	kref_init(&ctrl->kref);
	ctrl->id = id;

	mutex_lock(&mgr->amp_ctrls_lock);
	list_add(&ctrl->list, &mgr->amp_ctrls);
	mutex_unlock(&mgr->amp_ctrls_lock);

	BT_DBG("mgr %p ctrl %p", mgr, ctrl);

	return ctrl;
	}

	void amp_ctrl_list_flush(struct amp_mgr *mgr)
	{
	struct amp_ctrl ctrl, n;

	BT_DBG("mgr %p", mgr);

	mutex_lock(&mgr->amp_ctrls_lock);
	list_for_each_entry_safe(ctrl, n, &mgr->amp_ctrls, list) {
	list_del(&ctrl->list);
	amp_ctrl_put(ctrl);
	}
	mutex_unlock(&mgr->amp_ctrls_lock);
	}

	struct amp_ctrl amp_ctrl_lookup(struct amp_mgr mgr, u8 id)
	{
	struct amp_ctrl *ctrl;

	BT_DBG("mgr %p id %d", mgr, id);

	mutex_lock(&mgr->amp_ctrls_lock);
	list_for_each_entry(ctrl, &mgr->amp_ctrls, list) {
	if (ctrl->id == id) {
	amp_ctrl_get(ctrl);
	mutex_unlock(&mgr->amp_ctrls_lock);
	return ctrl;
	}
	}
	mutex_unlock(&mgr->amp_ctrls_lock);

	return NULL;
	}

	/* Physical Link interface */
	static u8 __next_handle(struct amp_mgr *mgr)
	{
	if (++mgr->handle == 0)
	mgr->handle = 1;

	return mgr->handle;
	}

	struct hci_conn phylink_add(struct hci_dev hdev, struct amp_mgr *mgr,
	u8 remote_id, bool out)
	{
	bdaddr_t *dst = &mgr->l2cap_conn->hcon->dst;
	struct hci_conn *hcon;
	u8 role = out ? HCI_ROLE_MASTER : HCI_ROLE_SLAVE;

	hcon = hci_conn_add(hdev, AMP_LINK, dst, role);
	if (!hcon)
	return NULL;

	BT_DBG("hcon %p dst %pMR", hcon, dst);

	hcon->state = BT_CONNECT;
	hcon->attempt++;
	hcon->handle = __next_handle(mgr);
	hcon->remote_id = remote_id;
	hcon->amp_mgr = amp_mgr_get(mgr);

	return hcon;
	}

	/* AMP crypto key generation interface */
	static int hmac_sha256(u8 key, u8 ksize, char plaintext, u8 psize, u8 *output)
	{
	struct crypto_shash *tfm;
	struct shash_desc *shash;
	int ret;

	if (!ksize)
	return -EINVAL;

	tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
	if (IS_ERR(tfm)) {
	BT_DBG("crypto_alloc_ahash failed: err %ld", PTR_ERR(tfm));
	return PTR_ERR(tfm);
	}

	ret = crypto_shash_setkey(tfm, key, ksize);
	if (ret) {
	BT_DBG("crypto_ahash_setkey failed: err %d", ret);
	goto failed;
	}

	shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(tfm),
	GFP_KERNEL);
	if (!shash) {
	ret = -ENOMEM;
	goto failed;
	}

	shash->tfm = tfm;
	shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP;

	ret = crypto_shash_digest(shash, plaintext, psize, output);

	kfree(shash);

	failed:
	crypto_free_shash(tfm);
	return ret;
	}

	int phylink_gen_key(struct hci_conn conn, u8 data, u8 len, u8 type)
	{
	struct hci_dev *hdev = conn->hdev;
	struct link_key *key;
	u8 keybuf[HCI_AMP_LINK_KEY_SIZE];
	u8 gamp_key[HCI_AMP_LINK_KEY_SIZE];
	int err;

	if (!hci_conn_check_link_mode(conn))
	return -EACCES;

	BT_DBG("conn %p key_type %d", conn, conn->key_type);

	/* Legacy key */
	if (conn->key_type < 3) {
	BT_ERR("Legacy key type %d", conn->key_type);
	return -EACCES;
	}

	*type = conn->key_type;
	*len = HCI_AMP_LINK_KEY_SIZE;

	key = hci_find_link_key(hdev, &conn->dst);
	if (!key) {
	BT_DBG("No Link key for conn %p dst %pMR", conn, &conn->dst);
	return -EACCES;
	}

	/* BR/EDR Link Key concatenated together with itself */
	memcpy(&keybuf[0], key->val, HCI_LINK_KEY_SIZE);
	memcpy(&keybuf[HCI_LINK_KEY_SIZE], key->val, HCI_LINK_KEY_SIZE);

	/* Derive Generic AMP Link Key (gamp) */
	err = hmac_sha256(keybuf, HCI_AMP_LINK_KEY_SIZE, "gamp", 4, gamp_key);
	if (err) {
	BT_ERR("Could not derive Generic AMP Key: err %d", err);
	return err;
	}

	if (conn->key_type == HCI_LK_DEBUG_COMBINATION) {
	BT_DBG("Use Generic AMP Key (gamp)");
	memcpy(data, gamp_key, HCI_AMP_LINK_KEY_SIZE);
	return err;
	}

	/* Derive Dedicated AMP Link Key: "802b" is 802.11 PAL keyID */
	return hmac_sha256(gamp_key, HCI_AMP_LINK_KEY_SIZE, "802b", 4, data);
	}

	static void read_local_amp_assoc_complete(struct hci_dev *hdev, u8 status,
	u16 opcode, struct sk_buff *skb)
	{
	struct hci_rp_read_local_amp_assoc rp = (void )skb->data;
	struct amp_assoc *assoc = &hdev->loc_assoc;
	size_t rem_len, frag_len;

	BT_DBG("%s status 0x%2.2x", hdev->name, rp->status);

	if (rp->status)
	goto send_rsp;

	frag_len = skb->len - sizeof(*rp);
	rem_len = __le16_to_cpu(rp->rem_len);

	if (rem_len > frag_len) {
	BT_DBG("frag_len %zu rem_len %zu", frag_len, rem_len);

	memcpy(assoc->data + assoc->offset, rp->frag, frag_len);
	assoc->offset += frag_len;

	/* Read other fragments */
	amp_read_loc_assoc_frag(hdev, rp->phy_handle);

	return;
	}

	memcpy(assoc->data + assoc->offset, rp->frag, rem_len);
	assoc->len = assoc->offset + rem_len;
	assoc->offset = 0;

	send_rsp:
	/* Send A2MP Rsp when all fragments are received */
	a2mp_send_getampassoc_rsp(hdev, rp->status);
	a2mp_send_create_phy_link_req(hdev, rp->status);
	}

	void amp_read_loc_assoc_frag(struct hci_dev *hdev, u8 phy_handle)
	{
	struct hci_cp_read_local_amp_assoc cp;
	struct amp_assoc *loc_assoc = &hdev->loc_assoc;
	struct hci_request req;
	int err = 0;

	BT_DBG("%s handle %d", hdev->name, phy_handle);

	cp.phy_handle = phy_handle;
	cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
	cp.len_so_far = cpu_to_le16(loc_assoc->offset);

	hci_req_init(&req, hdev);
	hci_req_add(&req, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
	err = hci_req_run_skb(&req, read_local_amp_assoc_complete);
	if (err < 0)
	a2mp_send_getampassoc_rsp(hdev, A2MP_STATUS_INVALID_CTRL_ID);
	}

	void amp_read_loc_assoc(struct hci_dev hdev, struct amp_mgr mgr)
	{
	struct hci_cp_read_local_amp_assoc cp;
	struct hci_request req;
	int err = 0;

	memset(&hdev->loc_assoc, 0, sizeof(struct amp_assoc));
	memset(&cp, 0, sizeof(cp));

	cp.max_len = cpu_to_le16(hdev->amp_assoc_size);

	set_bit(READ_LOC_AMP_ASSOC, &mgr->state);
	hci_req_init(&req, hdev);
	hci_req_add(&req, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
	hci_req_run_skb(&req, read_local_amp_assoc_complete);
	if (err < 0)
	a2mp_send_getampassoc_rsp(hdev, A2MP_STATUS_INVALID_CTRL_ID);
	}

	void amp_read_loc_assoc_final_data(struct hci_dev *hdev,
	struct hci_conn *hcon)
	{
	struct hci_cp_read_local_amp_assoc cp;
	struct amp_mgr *mgr = hcon->amp_mgr;
	struct hci_request req;
	int err = 0;

	cp.phy_handle = hcon->handle;
	cp.len_so_far = cpu_to_le16(0);
	cp.max_len = cpu_to_le16(hdev->amp_assoc_size);

	set_bit(READ_LOC_AMP_ASSOC_FINAL, &mgr->state);

	/* Read Local AMP Assoc final link information data */
	hci_req_init(&req, hdev);
	hci_req_add(&req, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
	hci_req_run_skb(&req, read_local_amp_assoc_complete);
	if (err < 0)
	a2mp_send_getampassoc_rsp(hdev, A2MP_STATUS_INVALID_CTRL_ID);
	}

	static void write_remote_amp_assoc_complete(struct hci_dev *hdev, u8 status,
	u16 opcode, struct sk_buff *skb)
	{
	struct hci_rp_write_remote_amp_assoc rp = (void )skb->data;

	BT_DBG("%s status 0x%2.2x phy_handle 0x%2.2x",
	hdev->name, rp->status, rp->phy_handle);

	if (rp->status)
	return;

	amp_write_rem_assoc_continue(hdev, rp->phy_handle);
	}

	/* Write AMP Assoc data fragments, returns true with last fragment written*/
	static bool amp_write_rem_assoc_frag(struct hci_dev *hdev,
	struct hci_conn *hcon)
	{
	struct hci_cp_write_remote_amp_assoc *cp;
	struct amp_mgr *mgr = hcon->amp_mgr;
	struct amp_ctrl *ctrl;
	struct hci_request req;
	u16 frag_len, len;

	ctrl = amp_ctrl_lookup(mgr, hcon->remote_id);
	if (!ctrl)
	return false;

	if (!ctrl->assoc_rem_len) {
	BT_DBG("all fragments are written");
	ctrl->assoc_rem_len = ctrl->assoc_len;
	ctrl->assoc_len_so_far = 0;

	amp_ctrl_put(ctrl);
	return true;
	}

	frag_len = min_t(u16, 248, ctrl->assoc_rem_len);
	len = frag_len + sizeof(*cp);

	cp = kzalloc(len, GFP_KERNEL);
	if (!cp) {
	amp_ctrl_put(ctrl);
	return false;
	}

	BT_DBG("hcon %p ctrl %p frag_len %u assoc_len %u rem_len %u",
	hcon, ctrl, frag_len, ctrl->assoc_len, ctrl->assoc_rem_len);

	cp->phy_handle = hcon->handle;
	cp->len_so_far = cpu_to_le16(ctrl->assoc_len_so_far);
	cp->rem_len = cpu_to_le16(ctrl->assoc_rem_len);
	memcpy(cp->frag, ctrl->assoc, frag_len);

	ctrl->assoc_len_so_far += frag_len;
	ctrl->assoc_rem_len -= frag_len;

	amp_ctrl_put(ctrl);

	hci_req_init(&req, hdev);
	hci_req_add(&req, HCI_OP_WRITE_REMOTE_AMP_ASSOC, sizeof(cp), &cp);
	hci_req_run_skb(&req, write_remote_amp_assoc_complete);

	kfree(cp);

	return false;
	}

	void amp_write_rem_assoc_continue(struct hci_dev *hdev, u8 handle)
	{
	struct hci_conn *hcon;

	BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);

	hcon = hci_conn_hash_lookup_handle(hdev, handle);
	if (!hcon)
	return;

	/* Send A2MP create phylink rsp when all fragments are written */
	if (amp_write_rem_assoc_frag(hdev, hcon))
	a2mp_send_create_phy_link_rsp(hdev, 0);
	}

	void amp_write_remote_assoc(struct hci_dev *hdev, u8 handle)
	{
	struct hci_conn *hcon;

	BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);

	hcon = hci_conn_hash_lookup_handle(hdev, handle);
	if (!hcon)
	return;

	BT_DBG("%s phy handle 0x%2.2x hcon %p", hdev->name, handle, hcon);

	amp_write_rem_assoc_frag(hdev, hcon);
	}

	static void create_phylink_complete(struct hci_dev *hdev, u8 status,
	u16 opcode)
	{
	struct hci_cp_create_phy_link *cp;

	BT_DBG("%s status 0x%2.2x", hdev->name, status);

	cp = hci_sent_cmd_data(hdev, HCI_OP_CREATE_PHY_LINK);
	if (!cp)
	return;

	hci_dev_lock(hdev);

	if (status) {
	struct hci_conn *hcon;

	hcon = hci_conn_hash_lookup_handle(hdev, cp->phy_handle);
	if (hcon)
	hci_conn_del(hcon);
	} else {
	amp_write_remote_assoc(hdev, cp->phy_handle);
	}

	hci_dev_unlock(hdev);
	}

	void amp_create_phylink(struct hci_dev hdev, struct amp_mgr mgr,
	struct hci_conn *hcon)
	{
	struct hci_cp_create_phy_link cp;
	struct hci_request req;

	cp.phy_handle = hcon->handle;

	BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
	hcon->handle);

	if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
	&cp.key_type)) {
	BT_DBG("Cannot create link key");
	return;
	}

	hci_req_init(&req, hdev);
	hci_req_add(&req, HCI_OP_CREATE_PHY_LINK, sizeof(cp), &cp);
	hci_req_run(&req, create_phylink_complete);
	}

	static void accept_phylink_complete(struct hci_dev *hdev, u8 status,
	u16 opcode)
	{
	struct hci_cp_accept_phy_link *cp;

	BT_DBG("%s status 0x%2.2x", hdev->name, status);

	if (status)
	return;

	cp = hci_sent_cmd_data(hdev, HCI_OP_ACCEPT_PHY_LINK);
	if (!cp)
	return;

	amp_write_remote_assoc(hdev, cp->phy_handle);
	}

	void amp_accept_phylink(struct hci_dev hdev, struct amp_mgr mgr,
	struct hci_conn *hcon)
	{
	struct hci_cp_accept_phy_link cp;
	struct hci_request req;

	cp.phy_handle = hcon->handle;

	BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
	hcon->handle);

	if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
	&cp.key_type)) {
	BT_DBG("Cannot create link key");
	return;
	}

	hci_req_init(&req, hdev);
	hci_req_add(&req, HCI_OP_ACCEPT_PHY_LINK, sizeof(cp), &cp);
	hci_req_run(&req, accept_phylink_complete);
	}

	void amp_physical_cfm(struct hci_conn bredr_hcon, struct hci_conn hs_hcon)
	{
	struct hci_dev *bredr_hdev = hci_dev_hold(bredr_hcon->hdev);
	struct amp_mgr *mgr = hs_hcon->amp_mgr;
	struct l2cap_chan *bredr_chan;

	BT_DBG("bredr_hcon %p hs_hcon %p mgr %p", bredr_hcon, hs_hcon, mgr);

	if (!bredr_hdev \|\| !mgr \|\| !mgr->bredr_chan)
	return;

	bredr_chan = mgr->bredr_chan;

	l2cap_chan_lock(bredr_chan);

	set_bit(FLAG_EFS_ENABLE, &bredr_chan->flags);
	bredr_chan->remote_amp_id = hs_hcon->remote_id;
	bredr_chan->local_amp_id = hs_hcon->hdev->id;
	bredr_chan->hs_hcon = hs_hcon;
	bredr_chan->conn->mtu = hs_hcon->hdev->block_mtu;

	__l2cap_physical_cfm(bredr_chan, 0);

	l2cap_chan_unlock(bredr_chan);

	hci_dev_put(bredr_hdev);
	}

	void amp_create_logical_link(struct l2cap_chan *chan)
	{
	struct hci_conn *hs_hcon = chan->hs_hcon;
	struct hci_cp_create_accept_logical_link cp;
	struct hci_dev *hdev;

	BT_DBG("chan %p hs_hcon %p dst %pMR", chan, hs_hcon,
	&chan->conn->hcon->dst);

	if (!hs_hcon)
	return;

	hdev = hci_dev_hold(chan->hs_hcon->hdev);
	if (!hdev)
	return;

	cp.phy_handle = hs_hcon->handle;

	cp.tx_flow_spec.id = chan->local_id;
	cp.tx_flow_spec.stype = chan->local_stype;
	cp.tx_flow_spec.msdu = cpu_to_le16(chan->local_msdu);
	cp.tx_flow_spec.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
	cp.tx_flow_spec.acc_lat = cpu_to_le32(chan->local_acc_lat);
	cp.tx_flow_spec.flush_to = cpu_to_le32(chan->local_flush_to);

	cp.rx_flow_spec.id = chan->remote_id;
	cp.rx_flow_spec.stype = chan->remote_stype;
	cp.rx_flow_spec.msdu = cpu_to_le16(chan->remote_msdu);
	cp.rx_flow_spec.sdu_itime = cpu_to_le32(chan->remote_sdu_itime);
	cp.rx_flow_spec.acc_lat = cpu_to_le32(chan->remote_acc_lat);
	cp.rx_flow_spec.flush_to = cpu_to_le32(chan->remote_flush_to);

	if (hs_hcon->out)
	hci_send_cmd(hdev, HCI_OP_CREATE_LOGICAL_LINK, sizeof(cp),
	&cp);
	else
	hci_send_cmd(hdev, HCI_OP_ACCEPT_LOGICAL_LINK, sizeof(cp),
	&cp);

	hci_dev_put(hdev);
	}

	void amp_disconnect_logical_link(struct hci_chan *hchan)
	{
	struct hci_conn *hcon = hchan->conn;
	struct hci_cp_disconn_logical_link cp;

	if (hcon->state != BT_CONNECTED) {
	BT_DBG("hchan %p not connected", hchan);
	return;
	}

	cp.log_handle = cpu_to_le16(hchan->handle);
	hci_send_cmd(hcon->hdev, HCI_OP_DISCONN_LOGICAL_LINK, sizeof(cp), &cp);
	}

	void amp_destroy_logical_link(struct hci_chan *hchan, u8 reason)
	{
	BT_DBG("hchan %p", hchan);

	hci_chan_del(hchan);
	}