qca-nss-drv/nss_dtls_cmn.c - manifest_repos/sdk - Git at Google

 /*
  **************************************************************************
  * Copyright (c) 2017-2021, The Linux Foundation. All rights reserved.
  * Permission to use, copy, modify, and/or distribute this software for
  * any purpose with or without fee is hereby granted, provided that the
  * above copyright notice and this permission notice appear in all copies.
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  * ANY SPECIAL, DIRECT, 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.
  **************************************************************************
  */

 #include "nss_tx_rx_common.h"
 #include "nss_dtls_cmn_log.h"
 #include "nss_dtls_cmn_stats.h"
 #include "nss_dtls_cmn_strings.h"

 #define NSS_DTLS_CMN_TX_TIMEOUT 3000 /* 3 Seconds */
 #define NSS_DTLS_CMN_INTERFACE_MAX_LONG BITS_TO_LONGS(NSS_MAX_NET_INTERFACES)

 /*
  * Private data structure.
  */
 static struct nss_dtls_cmn_pvt {
 	struct semaphore sem;
 	struct completion complete;
 	enum nss_dtls_cmn_error resp;
 	unsigned long if_map[NSS_DTLS_CMN_INTERFACE_MAX_LONG];
 } dtls_cmn_pvt;

 /*
  * nss_dtls_cmn_verify_ifnum()
  *	Verify if the interface number is a DTLS interface.
  */
 static bool nss_dtls_cmn_verify_ifnum(struct nss_ctx_instance *nss_ctx, uint32_t if_num)
 {
 	enum nss_dynamic_interface_type type = nss_dynamic_interface_get_type(nss_ctx, if_num);

 	if (type == NSS_DYNAMIC_INTERFACE_TYPE_DTLS_CMN_INNER)
 		return true;

 	if (type == NSS_DYNAMIC_INTERFACE_TYPE_DTLS_CMN_OUTER)
 		return true;

 	if (if_num == NSS_DTLS_INTERFACE)
 		return true;

 	return false;
 }

 /*
  * nss_dtls_cmn_handler()
  *	Handle NSS -> HLOS messages for dtls tunnel.
  */
 static void nss_dtls_cmn_handler(struct nss_ctx_instance *nss_ctx, struct nss_cmn_msg *ncm, void *data)
 {
 	nss_dtls_cmn_msg_callback_t cb;
 	void *app_data;

 	NSS_VERIFY_CTX_MAGIC(nss_ctx);

 	nss_trace("%px: handle event for interface num :%u", nss_ctx, ncm->interface);

 	/*
 	 * Is this a valid request/response packet?
 	 */
 	if (ncm->type >= NSS_DTLS_CMN_MSG_MAX) {
 		nss_warning("%px:Bad message type(%d) for DTLS interface %d", nss_ctx, ncm->type, ncm->interface);
 		return;
 	}

 	if (nss_cmn_get_msg_len(ncm) > sizeof(struct nss_dtls_cmn_msg)) {
 		nss_warning("%px:Bad message length(%d)", nss_ctx, ncm->len);
 		return;
 	}

 	if (ncm->type == NSS_DTLS_CMN_MSG_TYPE_SYNC_STATS) {
 		nss_dtls_cmn_stats_sync(nss_ctx, ncm);
 		nss_dtls_cmn_stats_notify(nss_ctx, ncm->interface);
 	}

 	/*
 	 * Update the callback and app_data for NOTIFY messages.
 	 */
 	if (ncm->response == NSS_CMN_RESPONSE_NOTIFY) {
 		ncm->cb = (nss_ptr_t)nss_core_get_msg_handler(nss_ctx, ncm->interface);
 		ncm->app_data = (nss_ptr_t)nss_ctx->nss_rx_interface_handlers[ncm->interface].app_data;
 	}

 	/*
 	 * Log failures.
 	 */
 	nss_core_log_msg_failures(nss_ctx, ncm);

 	/*
 	 * Trace messages.
 	 */
 	nss_dtls_cmn_log_rx_msg((struct nss_dtls_cmn_msg *)ncm);

 	/*
 	 * Callback.
 	 */
 	cb = (nss_dtls_cmn_msg_callback_t)ncm->cb;
 	app_data = (void *)ncm->app_data;

 	/*
 	 * Call DTLS session callback.
 	 */
 	if (!cb) {
 		nss_warning("%px: No callback for dtls session interface %d", nss_ctx, ncm->interface);
 		return;
 	}

 	nss_trace("%px: calling dtlsmgr event handler(%u)", nss_ctx, ncm->interface);
 	cb(app_data, ncm);
 }

 /*
  * nss_dtls_cmn_callback()
  *	Callback to handle the completion of NSS->HLOS messages.
  */
 static void nss_dtls_cmn_callback(void *app_data, struct nss_cmn_msg *ncm)
 {
 	/*
 	 * This callback is for synchronous operation. The caller sends its
 	 * response pointer which needs to be loaded with the response
 	 * data arriving from the NSS.
 	 */
 	enum nss_dtls_cmn_error *resp = (enum nss_dtls_cmn_error *)app_data;

 	*resp = (ncm->response == NSS_CMN_RESPONSE_ACK) ?  NSS_DTLS_CMN_ERROR_NONE : ncm->error;
 	complete(&dtls_cmn_pvt.complete);

 	return;
 }

 /*
  * nss_dtls_cmn_ifmap_get()
  *	Return DTLS common active interfaces map.
  */
 unsigned long *nss_dtls_cmn_ifmap_get(void)
 {
 	return dtls_cmn_pvt.if_map;
 }

 /*
  * nss_dtls_cmn_tx_buf()
  *	Transmit buffer over DTLS interface.
  */
 nss_tx_status_t nss_dtls_cmn_tx_buf(struct sk_buff *skb, uint32_t if_num, struct nss_ctx_instance *nss_ctx)
 {
 	if (!nss_dtls_cmn_verify_ifnum(nss_ctx, if_num))
 		return NSS_TX_FAILURE;

 	return nss_core_send_packet(nss_ctx, skb, if_num, H2N_BIT_FLAG_VIRTUAL_BUFFER | H2N_BIT_FLAG_BUFFER_REUSABLE);
 }
 EXPORT_SYMBOL(nss_dtls_cmn_tx_buf);

 /*
  * nss_dtls_cmn_tx_msg()
  *	Transmit a DTLS message to NSS firmware.
  */
 nss_tx_status_t nss_dtls_cmn_tx_msg(struct nss_ctx_instance *nss_ctx, struct nss_dtls_cmn_msg *msg)
 {
 	struct nss_cmn_msg *ncm = &msg->cm;

 	if (ncm->type >= NSS_DTLS_CMN_MSG_MAX) {
 		nss_warning("%px: dtls message type out of range: %d", nss_ctx, ncm->type);
 		return NSS_TX_FAILURE;
 	}

 	if (!nss_dtls_cmn_verify_ifnum(nss_ctx, ncm->interface)) {
 		nss_warning("%px: dtls message interface is bad: %u", nss_ctx, ncm->interface);
 		return NSS_TX_FAILURE;
 	}

 	/*
 	 * Trace messages.
 	 */
 	nss_dtls_cmn_log_tx_msg(msg);

 	return nss_core_send_cmd(nss_ctx, msg, sizeof(*msg), NSS_NBUF_PAYLOAD_SIZE);
 }
 EXPORT_SYMBOL(nss_dtls_cmn_tx_msg);

 /*
  * nss_dtls_cmn_tx_msg_sync()
  *	Transmit a DTLS message to NSS firmware synchronously.
  */
 nss_tx_status_t nss_dtls_cmn_tx_msg_sync(struct nss_ctx_instance *nss_ctx, uint32_t if_num,
 					enum nss_dtls_cmn_msg_type type, uint16_t len,
 					struct nss_dtls_cmn_msg *ndcm, enum nss_dtls_cmn_error *resp)
 {
 	struct nss_dtls_cmn_msg ndcm_local;
 	nss_tx_status_t status;
 	int ret;

 	/*
 	 * Length of the message should be the based on type.
 	 */
 	if (len > sizeof(ndcm_local.msg)) {
 		nss_warning("%px: (%u)Bad message length(%u) for type (%d)", nss_ctx, if_num, len, type);
 		return NSS_TX_FAILURE_TOO_LARGE;
 	}

 	/*
 	 * Response buffer is a required for copying the response for message.
 	 */
 	if (!resp) {
 		nss_warning("%px: (%u)Response buffer is empty, type(%d)", nss_ctx, if_num, type);
 		return NSS_TX_FAILURE_BAD_PARAM;
 	}

 	/*
 	 * TODO: this can be removed in future as we need to ensure that the response
 	 * memory is only updated when the current outstanding request is waiting.
 	 * This can be solved by introducing sequence no. in messages and only completing
 	 * the message if the sequence no. matches. For now this is solved by passing
 	 * a known memory dtls_cmn_pvt.resp.
 	 */
 	down(&dtls_cmn_pvt.sem);

 	/*
 	 * We need to copy the message content into the actual message
 	 * to be sent to NSS.
 	 */
 	nss_dtls_cmn_msg_init(&ndcm_local, if_num, type, len, nss_dtls_cmn_callback, &dtls_cmn_pvt.resp);
 	memcpy(&ndcm_local.msg, &ndcm->msg, len);

 	status = nss_dtls_cmn_tx_msg(nss_ctx, &ndcm_local);
 	if (status != NSS_TX_SUCCESS) {
 		nss_warning("%px: dtls_tx_msg failed", nss_ctx);
 		goto done;
 	}

 	ret = wait_for_completion_timeout(&dtls_cmn_pvt.complete, msecs_to_jiffies(NSS_DTLS_CMN_TX_TIMEOUT));
 	if (!ret) {
 		nss_warning("%px: DTLS msg tx failed due to timeout", nss_ctx);
 		status = NSS_TX_FAILURE_NOT_READY;
 		goto done;
 	}

 	/*
 	 * Read memory barrier.
 	 */
 	smp_rmb();

 	/*
 	 * Copy the response received.
 	 */
 	*resp = dtls_cmn_pvt.resp;

 	/*
 	 * Only in case of non-error response we will
 	 * indicate success.
 	 */
 	if (dtls_cmn_pvt.resp != NSS_DTLS_CMN_ERROR_NONE)
 		status = NSS_TX_FAILURE;

 done:
 	up(&dtls_cmn_pvt.sem);
 	return status;
 }
 EXPORT_SYMBOL(nss_dtls_cmn_tx_msg_sync);

 /*
  * nss_dtls_cmn_notify_register()
  *	Register a handler for notification from NSS firmware.
  */
 struct nss_ctx_instance *nss_dtls_cmn_notify_register(uint32_t if_num, nss_dtls_cmn_msg_callback_t ev_cb,
 							void *app_data)
 {
 	struct nss_ctx_instance *nss_ctx = nss_dtls_cmn_get_context();
 	uint32_t ret;

 	BUG_ON(!nss_ctx);

 	ret = nss_core_register_handler(nss_ctx, if_num, nss_dtls_cmn_handler, app_data);
 	if (ret != NSS_CORE_STATUS_SUCCESS) {
 		nss_warning("%px: unable to register event handler for interface(%u)", nss_ctx, if_num);
 		return NULL;
 	}

 	ret = nss_core_register_msg_handler(nss_ctx, if_num, ev_cb);
 	if (ret != NSS_CORE_STATUS_SUCCESS) {
 		nss_core_unregister_handler(nss_ctx, if_num);
 		nss_warning("%px: unable to register event handler for interface(%u)", nss_ctx, if_num);
 		return NULL;
 	}

 	return nss_ctx;
 }
 EXPORT_SYMBOL(nss_dtls_cmn_notify_register);

 /*
  * nss_dtls_cmn_notify_unregister()
  *	Unregister notification callback handler.
  */
 void nss_dtls_cmn_notify_unregister(uint32_t if_num)
 {
 	struct nss_ctx_instance *nss_ctx = nss_dtls_cmn_get_context();
 	uint32_t ret;

 	BUG_ON(!nss_ctx);

 	ret = nss_core_unregister_msg_handler(nss_ctx, if_num);
 	if (ret != NSS_CORE_STATUS_SUCCESS) {
 		nss_warning("%px: unable to unregister event handler for interface(%u)", nss_ctx, if_num);
 		return;
 	}

 	ret = nss_core_unregister_handler(nss_ctx, if_num);
 	if (ret != NSS_CORE_STATUS_SUCCESS) {
 		nss_warning("%px: unable to unregister event handler for interface(%u)", nss_ctx, if_num);
 		return;
 	}

 	return;
 }
 EXPORT_SYMBOL(nss_dtls_cmn_notify_unregister);

 /*
  * nss_dtls_cmn_register_if()
  *	Register data and event callback handlers for dynamic interface.
  */
 struct nss_ctx_instance *nss_dtls_cmn_register_if(uint32_t if_num,
 						  nss_dtls_cmn_data_callback_t data_cb,
 						  nss_dtls_cmn_msg_callback_t ev_cb,
 						  struct net_device *netdev,
 						  uint32_t features,
 						  uint32_t type,
 						  void *app_data)
 {
 	struct nss_ctx_instance *nss_ctx = nss_dtls_cmn_get_context();
 	uint32_t ret;

 	if (!nss_dtls_cmn_verify_ifnum(nss_ctx, if_num)) {
 		nss_warning("%px: DTLS Interface is not dynamic:%u", nss_ctx, if_num);
 		return NULL;
 	}

 	if (nss_ctx->subsys_dp_register[if_num].ndev) {
 		nss_warning("%px: Cannot find free slot for DTLS NSS I/F:%u", nss_ctx, if_num);
 		return NULL;
 	}

 	nss_core_register_subsys_dp(nss_ctx, if_num, data_cb, NULL, app_data, netdev, features);
 	nss_ctx->subsys_dp_register[if_num].type = type;

 	ret = nss_core_register_handler(nss_ctx, if_num, nss_dtls_cmn_handler, app_data);
 	if (ret != NSS_CORE_STATUS_SUCCESS) {
 		nss_warning("%px: unable to register event handler for interface(%u)", nss_ctx, if_num);
 		return NULL;
 	}

 	ret = nss_core_register_msg_handler(nss_ctx, if_num, ev_cb);
 	if (ret != NSS_CORE_STATUS_SUCCESS) {
 		nss_core_unregister_handler(nss_ctx, if_num);
 		nss_warning("%px: unable to register event handler for interface(%u)", nss_ctx, if_num);
 		return NULL;
 	}

 	/*
 	 * Atomically set the bitmap for the interface number.
 	 */
 	set_bit(if_num, dtls_cmn_pvt.if_map);
 	return nss_ctx;
 }
 EXPORT_SYMBOL(nss_dtls_cmn_register_if);

 /*
  * nss_dtls_cmn_unregister_if()
  *	Unregister data and event callback handlers for the interface.
  */
 void nss_dtls_cmn_unregister_if(uint32_t if_num)
 {
 	struct nss_ctx_instance *nss_ctx = nss_dtls_cmn_get_context();
 	uint32_t ret;

 	if (!nss_ctx->subsys_dp_register[if_num].ndev) {
 		nss_warning("%px: Cannot find registered netdev for DTLS NSS I/F:%u", nss_ctx, if_num);
 		return;
 	}

 	/*
 	 * Atomically clear the bitmap for the interface number.
 	 */
 	clear_bit(if_num, dtls_cmn_pvt.if_map);

 	ret = nss_core_unregister_msg_handler(nss_ctx, if_num);
 	if (ret != NSS_CORE_STATUS_SUCCESS) {
 		nss_warning("%px: unable to unregister event handler for interface(%u)", nss_ctx, if_num);
 		return;
 	}

 	nss_core_unregister_handler(nss_ctx, if_num);

 	nss_core_unregister_subsys_dp(nss_ctx, if_num);
 	nss_ctx->subsys_dp_register[if_num].type = 0;
 }
 EXPORT_SYMBOL(nss_dtls_cmn_unregister_if);

 /*
  * nss_dtls_get_context()
  *	Return DTLS NSS context.
  */
 struct nss_ctx_instance *nss_dtls_cmn_get_context(void)
 {
 	return (struct nss_ctx_instance *)&nss_top_main.nss[nss_top_main.dtls_handler_id];
 }
 EXPORT_SYMBOL(nss_dtls_cmn_get_context);

 /*
  * nss_dtls_cmn_msg_init()
  *	Initialize nss_dtls_cmn msg.
  */
 void nss_dtls_cmn_msg_init(struct nss_dtls_cmn_msg *ncm, uint32_t if_num,
 		       uint32_t type, uint32_t len, void *cb, void *app_data)
 {
 	nss_cmn_msg_init(&ncm->cm, if_num, type, len, cb, app_data);
 }
 EXPORT_SYMBOL(nss_dtls_cmn_msg_init);

 /*
  * nss_dtls_cmn_get_ifnum()
  *	Return DTLS interface number with coreid.
  */
 int32_t nss_dtls_cmn_get_ifnum(int32_t if_num)
 {
 	struct nss_ctx_instance *nss_ctx = nss_dtls_cmn_get_context();

 	NSS_VERIFY_CTX_MAGIC(nss_ctx);
 	return NSS_INTERFACE_NUM_APPEND_COREID(nss_ctx, if_num);
 }
 EXPORT_SYMBOL(nss_dtls_cmn_get_ifnum);

 /*
  * nss_dtls_cmn_register_handler()
  *	DTLS initialization.
  */
 void nss_dtls_cmn_register_handler(void)
 {
 	sema_init(&dtls_cmn_pvt.sem, 1);
 	init_completion(&dtls_cmn_pvt.complete);
 	nss_dtls_cmn_stats_dentry_create();
 	nss_dtls_cmn_strings_dentry_create();
 }
	/*
	**************************************************************************
	* Copyright (c) 2017-2021, The Linux Foundation. All rights reserved.
	* Permission to use, copy, modify, and/or distribute this software for
	* any purpose with or without fee is hereby granted, provided that the
	* above copyright notice and this permission notice appear in all copies.
	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	* ANY SPECIAL, DIRECT, 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.
	**************************************************************************
	*/

	#include "nss_tx_rx_common.h"
	#include "nss_dtls_cmn_log.h"
	#include "nss_dtls_cmn_stats.h"
	#include "nss_dtls_cmn_strings.h"

	#define NSS_DTLS_CMN_TX_TIMEOUT 3000 /* 3 Seconds */
	#define NSS_DTLS_CMN_INTERFACE_MAX_LONG BITS_TO_LONGS(NSS_MAX_NET_INTERFACES)

	/*
	* Private data structure.
	*/
	static struct nss_dtls_cmn_pvt {
	struct semaphore sem;
	struct completion complete;
	enum nss_dtls_cmn_error resp;
	unsigned long if_map[NSS_DTLS_CMN_INTERFACE_MAX_LONG];
	} dtls_cmn_pvt;

	/*
	* nss_dtls_cmn_verify_ifnum()
	* Verify if the interface number is a DTLS interface.
	*/
	static bool nss_dtls_cmn_verify_ifnum(struct nss_ctx_instance *nss_ctx, uint32_t if_num)
	{
	enum nss_dynamic_interface_type type = nss_dynamic_interface_get_type(nss_ctx, if_num);

	if (type == NSS_DYNAMIC_INTERFACE_TYPE_DTLS_CMN_INNER)
	return true;

	if (type == NSS_DYNAMIC_INTERFACE_TYPE_DTLS_CMN_OUTER)
	return true;

	if (if_num == NSS_DTLS_INTERFACE)
	return true;

	return false;
	}

	/*
	* nss_dtls_cmn_handler()
	* Handle NSS -> HLOS messages for dtls tunnel.
	*/
	static void nss_dtls_cmn_handler(struct nss_ctx_instance nss_ctx, struct nss_cmn_msg ncm, void *data)
	{
	nss_dtls_cmn_msg_callback_t cb;
	void *app_data;

	NSS_VERIFY_CTX_MAGIC(nss_ctx);

	nss_trace("%px: handle event for interface num :%u", nss_ctx, ncm->interface);

	/*
	* Is this a valid request/response packet?
	*/
	if (ncm->type >= NSS_DTLS_CMN_MSG_MAX) {
	nss_warning("%px:Bad message type(%d) for DTLS interface %d", nss_ctx, ncm->type, ncm->interface);
	return;
	}

	if (nss_cmn_get_msg_len(ncm) > sizeof(struct nss_dtls_cmn_msg)) {
	nss_warning("%px:Bad message length(%d)", nss_ctx, ncm->len);
	return;
	}

	if (ncm->type == NSS_DTLS_CMN_MSG_TYPE_SYNC_STATS) {
	nss_dtls_cmn_stats_sync(nss_ctx, ncm);
	nss_dtls_cmn_stats_notify(nss_ctx, ncm->interface);
	}

	/*
	* Update the callback and app_data for NOTIFY messages.
	*/
	if (ncm->response == NSS_CMN_RESPONSE_NOTIFY) {
	ncm->cb = (nss_ptr_t)nss_core_get_msg_handler(nss_ctx, ncm->interface);
	ncm->app_data = (nss_ptr_t)nss_ctx->nss_rx_interface_handlers[ncm->interface].app_data;
	}

	/*
	* Log failures.
	*/
	nss_core_log_msg_failures(nss_ctx, ncm);

	/*
	* Trace messages.
	*/
	nss_dtls_cmn_log_rx_msg((struct nss_dtls_cmn_msg *)ncm);

	/*
	* Callback.
	*/
	cb = (nss_dtls_cmn_msg_callback_t)ncm->cb;
	app_data = (void *)ncm->app_data;

	/*
	* Call DTLS session callback.
	*/
	if (!cb) {
	nss_warning("%px: No callback for dtls session interface %d", nss_ctx, ncm->interface);
	return;
	}

	nss_trace("%px: calling dtlsmgr event handler(%u)", nss_ctx, ncm->interface);
	cb(app_data, ncm);
	}

	/*
	* nss_dtls_cmn_callback()
	* Callback to handle the completion of NSS->HLOS messages.
	*/
	static void nss_dtls_cmn_callback(void app_data, struct nss_cmn_msg ncm)
	{
	/*
	* This callback is for synchronous operation. The caller sends its
	* response pointer which needs to be loaded with the response
	* data arriving from the NSS.
	*/
	enum nss_dtls_cmn_error resp = (enum nss_dtls_cmn_error )app_data;

	*resp = (ncm->response == NSS_CMN_RESPONSE_ACK) ? NSS_DTLS_CMN_ERROR_NONE : ncm->error;
	complete(&dtls_cmn_pvt.complete);

	return;
	}

	/*
	* nss_dtls_cmn_ifmap_get()
	* Return DTLS common active interfaces map.
	*/
	unsigned long *nss_dtls_cmn_ifmap_get(void)
	{
	return dtls_cmn_pvt.if_map;
	}

	/*
	* nss_dtls_cmn_tx_buf()
	* Transmit buffer over DTLS interface.
	*/
	nss_tx_status_t nss_dtls_cmn_tx_buf(struct sk_buff skb, uint32_t if_num, struct nss_ctx_instance nss_ctx)
	{
	if (!nss_dtls_cmn_verify_ifnum(nss_ctx, if_num))
	return NSS_TX_FAILURE;

	return nss_core_send_packet(nss_ctx, skb, if_num, H2N_BIT_FLAG_VIRTUAL_BUFFER \| H2N_BIT_FLAG_BUFFER_REUSABLE);
	}
	EXPORT_SYMBOL(nss_dtls_cmn_tx_buf);

	/*
	* nss_dtls_cmn_tx_msg()
	* Transmit a DTLS message to NSS firmware.
	*/
	nss_tx_status_t nss_dtls_cmn_tx_msg(struct nss_ctx_instance nss_ctx, struct nss_dtls_cmn_msg msg)
	{
	struct nss_cmn_msg *ncm = &msg->cm;

	if (ncm->type >= NSS_DTLS_CMN_MSG_MAX) {
	nss_warning("%px: dtls message type out of range: %d", nss_ctx, ncm->type);
	return NSS_TX_FAILURE;
	}

	if (!nss_dtls_cmn_verify_ifnum(nss_ctx, ncm->interface)) {
	nss_warning("%px: dtls message interface is bad: %u", nss_ctx, ncm->interface);
	return NSS_TX_FAILURE;
	}

	/*
	* Trace messages.
	*/
	nss_dtls_cmn_log_tx_msg(msg);

	return nss_core_send_cmd(nss_ctx, msg, sizeof(*msg), NSS_NBUF_PAYLOAD_SIZE);
	}
	EXPORT_SYMBOL(nss_dtls_cmn_tx_msg);

	/*
	* nss_dtls_cmn_tx_msg_sync()
	* Transmit a DTLS message to NSS firmware synchronously.
	*/
	nss_tx_status_t nss_dtls_cmn_tx_msg_sync(struct nss_ctx_instance *nss_ctx, uint32_t if_num,
	enum nss_dtls_cmn_msg_type type, uint16_t len,
	struct nss_dtls_cmn_msg ndcm, enum nss_dtls_cmn_error resp)
	{
	struct nss_dtls_cmn_msg ndcm_local;
	nss_tx_status_t status;
	int ret;

	/*
	* Length of the message should be the based on type.
	*/
	if (len > sizeof(ndcm_local.msg)) {
	nss_warning("%px: (%u)Bad message length(%u) for type (%d)", nss_ctx, if_num, len, type);
	return NSS_TX_FAILURE_TOO_LARGE;
	}

	/*
	* Response buffer is a required for copying the response for message.
	*/
	if (!resp) {
	nss_warning("%px: (%u)Response buffer is empty, type(%d)", nss_ctx, if_num, type);
	return NSS_TX_FAILURE_BAD_PARAM;
	}

	/*
	* TODO: this can be removed in future as we need to ensure that the response
	* memory is only updated when the current outstanding request is waiting.
	* This can be solved by introducing sequence no. in messages and only completing
	* the message if the sequence no. matches. For now this is solved by passing
	* a known memory dtls_cmn_pvt.resp.
	*/
	down(&dtls_cmn_pvt.sem);

	/*
	* We need to copy the message content into the actual message
	* to be sent to NSS.
	*/
	nss_dtls_cmn_msg_init(&ndcm_local, if_num, type, len, nss_dtls_cmn_callback, &dtls_cmn_pvt.resp);
	memcpy(&ndcm_local.msg, &ndcm->msg, len);

	status = nss_dtls_cmn_tx_msg(nss_ctx, &ndcm_local);
	if (status != NSS_TX_SUCCESS) {
	nss_warning("%px: dtls_tx_msg failed", nss_ctx);
	goto done;
	}

	ret = wait_for_completion_timeout(&dtls_cmn_pvt.complete, msecs_to_jiffies(NSS_DTLS_CMN_TX_TIMEOUT));
	if (!ret) {
	nss_warning("%px: DTLS msg tx failed due to timeout", nss_ctx);
	status = NSS_TX_FAILURE_NOT_READY;
	goto done;
	}

	/*
	* Read memory barrier.
	*/
	smp_rmb();

	/*
	* Copy the response received.
	*/
	*resp = dtls_cmn_pvt.resp;

	/*
	* Only in case of non-error response we will
	* indicate success.
	*/
	if (dtls_cmn_pvt.resp != NSS_DTLS_CMN_ERROR_NONE)
	status = NSS_TX_FAILURE;

	done:
	up(&dtls_cmn_pvt.sem);
	return status;
	}
	EXPORT_SYMBOL(nss_dtls_cmn_tx_msg_sync);

	/*
	* nss_dtls_cmn_notify_register()
	* Register a handler for notification from NSS firmware.
	*/
	struct nss_ctx_instance *nss_dtls_cmn_notify_register(uint32_t if_num, nss_dtls_cmn_msg_callback_t ev_cb,
	void *app_data)
	{
	struct nss_ctx_instance *nss_ctx = nss_dtls_cmn_get_context();
	uint32_t ret;

	BUG_ON(!nss_ctx);

	ret = nss_core_register_handler(nss_ctx, if_num, nss_dtls_cmn_handler, app_data);
	if (ret != NSS_CORE_STATUS_SUCCESS) {
	nss_warning("%px: unable to register event handler for interface(%u)", nss_ctx, if_num);
	return NULL;
	}

	ret = nss_core_register_msg_handler(nss_ctx, if_num, ev_cb);
	if (ret != NSS_CORE_STATUS_SUCCESS) {
	nss_core_unregister_handler(nss_ctx, if_num);
	nss_warning("%px: unable to register event handler for interface(%u)", nss_ctx, if_num);
	return NULL;
	}

	return nss_ctx;
	}
	EXPORT_SYMBOL(nss_dtls_cmn_notify_register);

	/*
	* nss_dtls_cmn_notify_unregister()
	* Unregister notification callback handler.
	*/
	void nss_dtls_cmn_notify_unregister(uint32_t if_num)
	{
	struct nss_ctx_instance *nss_ctx = nss_dtls_cmn_get_context();
	uint32_t ret;

	BUG_ON(!nss_ctx);

	ret = nss_core_unregister_msg_handler(nss_ctx, if_num);
	if (ret != NSS_CORE_STATUS_SUCCESS) {
	nss_warning("%px: unable to unregister event handler for interface(%u)", nss_ctx, if_num);
	return;
	}

	ret = nss_core_unregister_handler(nss_ctx, if_num);
	if (ret != NSS_CORE_STATUS_SUCCESS) {
	nss_warning("%px: unable to unregister event handler for interface(%u)", nss_ctx, if_num);
	return;
	}

	return;
	}
	EXPORT_SYMBOL(nss_dtls_cmn_notify_unregister);

	/*
	* nss_dtls_cmn_register_if()
	* Register data and event callback handlers for dynamic interface.
	*/
	struct nss_ctx_instance *nss_dtls_cmn_register_if(uint32_t if_num,
	nss_dtls_cmn_data_callback_t data_cb,
	nss_dtls_cmn_msg_callback_t ev_cb,
	struct net_device *netdev,
	uint32_t features,
	uint32_t type,
	void *app_data)
	{
	struct nss_ctx_instance *nss_ctx = nss_dtls_cmn_get_context();
	uint32_t ret;

	if (!nss_dtls_cmn_verify_ifnum(nss_ctx, if_num)) {
	nss_warning("%px: DTLS Interface is not dynamic:%u", nss_ctx, if_num);
	return NULL;
	}

	if (nss_ctx->subsys_dp_register[if_num].ndev) {
	nss_warning("%px: Cannot find free slot for DTLS NSS I/F:%u", nss_ctx, if_num);
	return NULL;
	}

	nss_core_register_subsys_dp(nss_ctx, if_num, data_cb, NULL, app_data, netdev, features);
	nss_ctx->subsys_dp_register[if_num].type = type;

	ret = nss_core_register_handler(nss_ctx, if_num, nss_dtls_cmn_handler, app_data);
	if (ret != NSS_CORE_STATUS_SUCCESS) {
	nss_warning("%px: unable to register event handler for interface(%u)", nss_ctx, if_num);
	return NULL;
	}

	ret = nss_core_register_msg_handler(nss_ctx, if_num, ev_cb);
	if (ret != NSS_CORE_STATUS_SUCCESS) {
	nss_core_unregister_handler(nss_ctx, if_num);
	nss_warning("%px: unable to register event handler for interface(%u)", nss_ctx, if_num);
	return NULL;
	}

	/*
	* Atomically set the bitmap for the interface number.
	*/
	set_bit(if_num, dtls_cmn_pvt.if_map);
	return nss_ctx;
	}
	EXPORT_SYMBOL(nss_dtls_cmn_register_if);

	/*
	* nss_dtls_cmn_unregister_if()
	* Unregister data and event callback handlers for the interface.
	*/
	void nss_dtls_cmn_unregister_if(uint32_t if_num)
	{
	struct nss_ctx_instance *nss_ctx = nss_dtls_cmn_get_context();
	uint32_t ret;

	if (!nss_ctx->subsys_dp_register[if_num].ndev) {
	nss_warning("%px: Cannot find registered netdev for DTLS NSS I/F:%u", nss_ctx, if_num);
	return;
	}

	/*
	* Atomically clear the bitmap for the interface number.
	*/
	clear_bit(if_num, dtls_cmn_pvt.if_map);

	ret = nss_core_unregister_msg_handler(nss_ctx, if_num);
	if (ret != NSS_CORE_STATUS_SUCCESS) {
	nss_warning("%px: unable to unregister event handler for interface(%u)", nss_ctx, if_num);
	return;
	}

	nss_core_unregister_handler(nss_ctx, if_num);

	nss_core_unregister_subsys_dp(nss_ctx, if_num);
	nss_ctx->subsys_dp_register[if_num].type = 0;
	}
	EXPORT_SYMBOL(nss_dtls_cmn_unregister_if);

	/*
	* nss_dtls_get_context()
	* Return DTLS NSS context.
	*/
	struct nss_ctx_instance *nss_dtls_cmn_get_context(void)
	{
	return (struct nss_ctx_instance *)&nss_top_main.nss[nss_top_main.dtls_handler_id];
	}
	EXPORT_SYMBOL(nss_dtls_cmn_get_context);

	/*
	* nss_dtls_cmn_msg_init()
	* Initialize nss_dtls_cmn msg.
	*/
	void nss_dtls_cmn_msg_init(struct nss_dtls_cmn_msg *ncm, uint32_t if_num,
	uint32_t type, uint32_t len, void cb, void app_data)
	{
	nss_cmn_msg_init(&ncm->cm, if_num, type, len, cb, app_data);
	}
	EXPORT_SYMBOL(nss_dtls_cmn_msg_init);

	/*
	* nss_dtls_cmn_get_ifnum()
	* Return DTLS interface number with coreid.
	*/
	int32_t nss_dtls_cmn_get_ifnum(int32_t if_num)
	{
	struct nss_ctx_instance *nss_ctx = nss_dtls_cmn_get_context();

	NSS_VERIFY_CTX_MAGIC(nss_ctx);
	return NSS_INTERFACE_NUM_APPEND_COREID(nss_ctx, if_num);
	}
	EXPORT_SYMBOL(nss_dtls_cmn_get_ifnum);

	/*
	* nss_dtls_cmn_register_handler()
	* DTLS initialization.
	*/
	void nss_dtls_cmn_register_handler(void)
	{
	sema_init(&dtls_cmn_pvt.sem, 1);
	init_completion(&dtls_cmn_pvt.complete);
	nss_dtls_cmn_stats_dentry_create();
	nss_dtls_cmn_strings_dentry_create();
	}