nss_capwap.c

/*
 **************************************************************************
 * Copyright (c) 2014, 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.
 **************************************************************************
 */

 /*
  * nss_capwap.h
  *	NSS CAPWAP driver interface APIs
  */
#include "nss_core.h"
#include <nss_hal.h>
#include <linux/module.h>
#include "nss_cmn.h"
#include "nss_capwap.h"

/*
 * Spinlock for protecting tunnel operations colliding with a tunnel destroy
 */
DEFINE_SPINLOCK(nss_capwap_spinlock);

/*
 * Array of pointer for NSS CAPWAP handles. Each handle has per-tunnel
 * stats based on the if_num which is an index.
 *
 * Per CAPWAP tunnel/interface number instance.
 */
struct nss_capwap_handle {
	atomic_t refcnt;			/**< Reference count on the tunnel */
	uint32_t interface_num;			/**< Interface number */
	uint32_t tunnel_status;			/**< 0=disable, 1=enabled */
	struct nss_ctx_instance *ctx;		/**< Pointer to context */
	nss_capwap_msg_callback_t msg_callback;	/**< Msg callback */
	void *app_data;				/**< App data (argument) */
	struct nss_capwap_tunnel_stats stats;	/**< Stats per-interface number */
};
static struct nss_capwap_handle *nss_capwap_hdl[NSS_MAX_DYNAMIC_INTERFACES];

/*
 * Global definitions.
 */
extern struct nss_top_instance nss_top_main;

/*
 * nss_capwap_verify_if_num()
 *	Verify if_num passed to us.
 */
static bool nss_capwap_verify_if_num(uint32_t if_num)
{
	if (nss_is_dynamic_interface(if_num) == false) {
		return false;
	}

	if (nss_dynamic_interface_get_type(if_num) != NSS_DYNAMIC_INTERFACE_TYPE_CAPWAP) {
		return false;
	}

	return true;
}

/*
 * nss_capwap_refcnt_inc()
 *	Increments refcnt on the tunnel.
 */
static void nss_capwap_refcnt_inc(int32_t if_num)
{
	if_num = if_num - NSS_DYNAMIC_IF_START;
	atomic_inc(&nss_capwap_hdl[if_num]->refcnt);
	nss_assert(atomic_read(&nss_capwap_hdl[if_num]->refcnt) > 0);
}

/*
 * nss_capwap_refcnt_dec()
 *	Decrements refcnt on the tunnel.
 */
static void nss_capwap_refcnt_dec(int32_t if_num)
{
	if_num = if_num - NSS_DYNAMIC_IF_START;
	nss_assert(atomic_read(&nss_capwap_hdl[if_num]->refcnt) > 0);
	atomic_dec(&nss_capwap_hdl[if_num]->refcnt);
}

/*
 * nss_capwap_get_refcnt()
 *	Get refcnt on the tunnel.
 */
static uint32_t nss_capwap_get_refcnt(int32_t if_num)
{
	if_num = if_num - NSS_DYNAMIC_IF_START;
	return atomic_read(&nss_capwap_hdl[if_num]->refcnt);
}

/*
 * nss_capwap_set_msg_callback()
 *	This sets the message callback handler and its associated context
 */
static void nss_capwap_set_msg_callback(int32_t if_num, nss_capwap_msg_callback_t cb, void *app_data)
{
	struct nss_capwap_handle *h;

	h = nss_capwap_hdl[if_num - NSS_DYNAMIC_IF_START];
	if (!h) {
		return;
	}

	h->app_data = app_data;
	h->msg_callback = cb;
}

/*
 * nss_capwap_get_msg_callback()
 *	This gets the message callback handler and its associated context
 */
static nss_capwap_msg_callback_t nss_capwap_get_msg_callback(int32_t if_num, void **app_data)
{
	struct nss_capwap_handle *h;

	h = nss_capwap_hdl[if_num - NSS_DYNAMIC_IF_START];
	if (!h) {
		*app_data = NULL;
		return NULL;
	}

	*app_data = h->app_data;
	return h->msg_callback;
}

/*
 * nss_capwapmgr_update_stats()
 *	Update per-tunnel stats for each CAPWAP interface.
 */
static void nss_capwapmgr_update_stats(struct nss_capwap_handle *handle, struct nss_capwap_stats_msg *fstats)
{
	struct nss_capwap_tunnel_stats *stats;

	stats = &handle->stats;

	stats->rx_segments += fstats->rx_segments;
	stats->tx_segments += fstats->tx_segments;
	stats->dtls_pkts += fstats->dtls_pkts;
	stats->oversize_drops += fstats->oversize_drops;
	stats->frag_timeout_drops += fstats->frag_timeout_drops;
	stats->rx_queue_full_drops += fstats->rx_queue_full_drops;
	stats->rx_n2h_queue_full_drops += fstats->rx_n2h_queue_full_drops;
	stats->rx_mem_failure_drops += fstats->rx_mem_failure_drops;

	stats->tx_queue_full_drops += fstats->tx_queue_full_drops;
	stats->tx_mem_failure_drops += fstats->tx_mem_failure_drops;

	/*
	 * add pnode stats now.
	 */
	stats->pnode_stats.rx_packets += fstats->pnode_stats.rx_packets;
	stats->pnode_stats.rx_bytes += fstats->pnode_stats.rx_bytes;
	stats->pnode_stats.rx_dropped += fstats->pnode_stats.rx_dropped;
	stats->pnode_stats.tx_packets += fstats->pnode_stats.tx_packets;
	stats->pnode_stats.tx_bytes += fstats->pnode_stats.tx_bytes;
}

/*
 * nss_capwap_handler()
 * 	Handle NSS -> HLOS messages for CAPWAP
 */
static void nss_capwap_msg_handler(struct nss_ctx_instance *nss_ctx, struct nss_cmn_msg *ncm, __attribute__((unused))void *app_data)
{
	struct nss_capwap_msg *ntm = (struct nss_capwap_msg *)ncm;
	nss_capwap_msg_callback_t cb;

	/*
	 * Is this a valid request/response packet?
	 */
	if (ncm->type > NSS_CAPWAP_MSG_TYPE_MAX) {
		nss_warning("%p: received invalid message %d for CAPWAP interface", nss_ctx, ncm->type);
		return;
	}

	if (ncm->len > sizeof(struct nss_capwap_msg)) {
		nss_warning("%p: Length of message is greater than required: %d", nss_ctx, ncm->interface);
		return;
	}

	nss_core_log_msg_failures(nss_ctx, ncm);

	switch (ntm->cm.type) {
	case NSS_CAPWAP_MSG_TYPE_SYNC_STATS: {
			uint32_t if_num;

			if_num = ncm->interface - NSS_DYNAMIC_IF_START;
			if (nss_capwap_hdl[if_num] != NULL) {
				nss_capwapmgr_update_stats(nss_capwap_hdl[if_num], &ntm->msg.stats);
			}
		}
	}

	/*
	 * Update the callback and app_data for NOTIFY messages.
	 */
	if (ncm->response == NSS_CMM_RESPONSE_NOTIFY) {
		void *app_data;

		ncm->cb = (uint32_t)nss_capwap_get_msg_callback(ncm->interface, &app_data);
		ncm->app_data = (uint32_t)app_data;
	}

	/*
	 * Do we have a callback
	 */
	if (!ncm->cb) {
		nss_trace("%p: cb is null for interface %d", nss_ctx, ncm->interface);
		return;
	}

	cb = (nss_capwap_msg_callback_t)ncm->cb;
	cb((void *)ncm->app_data, ntm);
}

/*
 * nss_capwap_instance_alloc()
 *	Allocate CAPWAP tunnel instance
 */
static bool nss_capwap_instance_alloc(struct nss_ctx_instance *nss_ctx, uint32_t if_num)
{
	struct nss_capwap_handle *h;

	/*
	 * Allocate a handle
	 */
	h = kmalloc(sizeof(struct nss_capwap_handle), GFP_ATOMIC);
	if (h == NULL) {
		nss_warning("%p: no memory for allocating CAPWAP instance for interface : %d", nss_ctx, if_num);
		return false;
	}
	memset(h, 0, sizeof (struct nss_capwap_handle));
	atomic_set(&h->refcnt, 0);
	memset(&h->stats, 0, sizeof (struct nss_capwap_tunnel_stats));
	h->interface_num = if_num;

	spin_lock(&nss_capwap_spinlock);
	if (nss_capwap_hdl[if_num - NSS_DYNAMIC_IF_START] != NULL) {
		spin_unlock(&nss_capwap_spinlock);
		kfree(h);
		nss_warning("%p: Another thread is already allocated instance for :%d", nss_ctx, if_num);
		return false;
	}

	nss_capwap_hdl[if_num - NSS_DYNAMIC_IF_START] = h;
	spin_unlock(&nss_capwap_spinlock);

	return true;
}

/*
 * nss_capwap_tx_msg()
 * 	Transmit a CAPWAP message to NSS FW. Don't call this from softirq/interrupts.
 */
nss_tx_status_t nss_capwap_tx_msg(struct nss_ctx_instance *nss_ctx, struct nss_capwap_msg *msg)
{
	struct nss_capwap_msg *nm;
	struct nss_cmn_msg *ncm = &msg->cm;
	struct sk_buff *nbuf;
	int32_t status;
	int32_t if_num;

	BUG_ON(in_interrupt());
	BUG_ON(in_softirq());
	BUG_ON(in_serving_softirq());

	if (nss_capwap_verify_if_num(msg->cm.interface) == false) {
		return NSS_TX_FAILURE_BAD_PARAM;
	}

	if (ncm->type >= NSS_CAPWAP_MSG_TYPE_MAX) {
		return NSS_TX_FAILURE_BAD_PARAM;
	}

	if_num = msg->cm.interface - NSS_DYNAMIC_IF_START;
	spin_lock(&nss_capwap_spinlock);
	if (!nss_capwap_hdl[if_num]) {
		spin_unlock(&nss_capwap_spinlock);
		nss_warning("%p: capwap tunnel if_num is not there: %d", nss_ctx, msg->cm.interface);
		return NSS_TX_FAILURE_BAD_PARAM;
	}
	nss_capwap_refcnt_inc(msg->cm.interface);
	spin_unlock(&nss_capwap_spinlock);

	if (unlikely(nss_ctx->state != NSS_CORE_STATE_INITIALIZED)) {
		nss_warning("%p: capwap msg dropped as core not ready", nss_ctx);
		status = NSS_TX_FAILURE_NOT_READY;
		goto out;
	}

	if (ncm->len > sizeof(struct nss_capwap_msg)) {
		nss_warning("%p: message length is invalid: %d", nss_ctx, ncm->len);
		status = NSS_TX_FAILURE_BAD_PARAM;
		goto out;
	}

	nbuf = dev_alloc_skb(NSS_NBUF_PAYLOAD_SIZE);
	if (unlikely(!nbuf)) {
		spin_lock_bh(&nss_ctx->nss_top->stats_lock);
		nss_ctx->nss_top->stats_drv[NSS_STATS_DRV_NBUF_ALLOC_FAILS]++;
		spin_unlock_bh(&nss_ctx->nss_top->stats_lock);
		nss_warning("%p: msg dropped as command allocation failed", nss_ctx);
		status = NSS_TX_FAILURE;
		goto out;
	}

	/*
	 * Copy the message to our skb
	 */
	nm = (struct nss_capwap_msg *)skb_put(nbuf, sizeof(struct nss_capwap_msg));
	memcpy(nm, msg, sizeof(struct nss_capwap_msg));

	status = nss_core_send_buffer(nss_ctx, 0, nbuf, NSS_IF_CMD_QUEUE, H2N_BUFFER_CTRL, 0);
	if (status != NSS_CORE_STATUS_SUCCESS) {
		dev_kfree_skb_any(nbuf);
		nss_warning("%p: Unable to enqueue 'capwap message' \n", nss_ctx);
		goto out;
	}

	nss_hal_send_interrupt(nss_ctx->nmap, nss_ctx->h2n_desc_rings[NSS_IF_CMD_QUEUE].desc_ring.int_bit,
				NSS_REGS_H2N_INTR_STATUS_DATA_COMMAND_QUEUE);

	NSS_PKT_STATS_INCREMENT(nss_ctx, &nss_ctx->nss_top->stats_drv[NSS_STATS_DRV_TX_CMD_REQ]);

out:
	nss_capwap_refcnt_dec(msg->cm.interface);
	return status;
}
EXPORT_SYMBOL(nss_capwap_tx_msg);

/*
 * nss_capwap_tx_data()
 *	Transmit data buffer (skb) to a NSS interface number
 */
nss_tx_status_t nss_capwap_tx_data(struct nss_ctx_instance *nss_ctx, struct sk_buff *os_buf, uint32_t if_num)
{
	return nss_if_tx_buf(nss_ctx, os_buf, if_num);
}
EXPORT_SYMBOL(nss_capwap_tx_data);

/*
 ***********************************
 * Register/Unregister/Miscellaneous APIs
 ***********************************
 */

/*
 * nss_capwap_get_stats()
 *	API for getting stats from a CAPWAP tunnel interface stats
 */
bool nss_capwap_get_stats(uint32_t if_num, struct nss_capwap_tunnel_stats *stats)
{
	if (nss_capwap_verify_if_num(if_num) == false) {
		return false;
	}

	if_num = if_num - NSS_DYNAMIC_IF_START;
	spin_lock(&nss_capwap_spinlock);
	if (nss_capwap_hdl[if_num] == NULL) {
		spin_unlock(&nss_capwap_spinlock);
		return false;
	}

	memcpy(stats, &nss_capwap_hdl[if_num]->stats, sizeof(struct nss_capwap_tunnel_stats));
	spin_unlock(&nss_capwap_spinlock);
	return true;
}
EXPORT_SYMBOL(nss_capwap_get_stats);

/*
 * nss_capwap_notify_register()
 *	Registers a message notifier with NSS FW. It should not be called from
 *	softirq or interrupts.
 */
struct nss_ctx_instance *nss_capwap_notify_register(uint32_t if_num, nss_capwap_msg_callback_t cb, void *app_data)
{
	struct nss_ctx_instance *nss_ctx;

	nss_ctx = &nss_top_main.nss[nss_top_main.capwap_handler_id];

	if (nss_capwap_verify_if_num(if_num) == false) {
		nss_warning("%p: notfiy register received for invalid interface %d", nss_ctx, if_num);
		return NULL;
	}

	spin_lock(&nss_capwap_spinlock);
	if (nss_capwap_hdl[if_num - NSS_DYNAMIC_IF_START] != NULL) {
		spin_unlock(&nss_capwap_spinlock);
		nss_warning("%p: notfiy register tunnel already exists for interface %d", nss_ctx, if_num);
		return NULL;
	}
	spin_unlock(&nss_capwap_spinlock);

	return nss_ctx;
}
EXPORT_SYMBOL(nss_capwap_notify_register);

/*
 * nss_capwap_notify_unregister()
 *	unregister the CAPWAP notifier for the given interface number (if_num).
 *	It shouldn't be called from softirq or interrupts.
 */
nss_tx_status_t nss_capwap_notify_unregister(struct nss_ctx_instance *nss_ctx, uint32_t if_num)
{
	struct nss_top_instance *nss_top;
	int index;

	if (nss_capwap_verify_if_num(if_num) == false) {
		nss_warning("%p: notify unregister received for invalid interface %d", nss_ctx, if_num);
		return NSS_TX_FAILURE_BAD_PARAM;
	}

	nss_top = nss_ctx->nss_top;
	if (nss_top == NULL) {
		nss_warning("%p: notify unregister received for invalid nss_top %d", nss_ctx, if_num);
		return NSS_TX_FAILURE_BAD_PARAM;
	}

	index = if_num - NSS_DYNAMIC_IF_START;
	spin_lock(&nss_capwap_spinlock);
	if (nss_capwap_hdl[index] == NULL) {
		spin_unlock(&nss_capwap_spinlock);
		nss_warning("%p: notify unregister received for unallocated if_num: %d", nss_ctx, if_num);
		return NSS_TX_FAILURE_BAD_PARAM;
	}

	/*
	 * It's the responsibility of caller to wait and call us again. We return failure saying
	 * that we can't remove msg handler now.
	 */
	if (nss_capwap_get_refcnt(if_num) != 0) {
		spin_unlock(&nss_capwap_spinlock);
		nss_warning("%p: notify unregister tunnel %d: has reference", nss_ctx, if_num);
		return NSS_TX_FAILURE_QUEUE;
	}

	nss_capwap_set_msg_callback(if_num, NULL, NULL);
	spin_unlock(&nss_capwap_spinlock);

	return NSS_TX_SUCCESS;
}
EXPORT_SYMBOL(nss_capwap_notify_unregister);

/*
 * nss_capwap_data_register()
 *	Registers a data packet notifier with NSS FW.
 */
struct nss_ctx_instance *nss_capwap_data_register(uint32_t if_num, nss_capwap_buf_callback_t cb, void *app_data)
{
	struct nss_ctx_instance *nss_ctx;
	int core_status;

	nss_ctx = nss_capwap_get_ctx();
	if (nss_capwap_verify_if_num(if_num) == false) {
		nss_warning("%p: data register received for invalid interface %d", nss_ctx, if_num);
		return NULL;
	}

	spin_lock(&nss_capwap_spinlock);
	if (nss_ctx->nss_top->if_ctx[if_num] != NULL) {
		spin_unlock(&nss_capwap_spinlock);
		return NULL;
	}
	spin_unlock(&nss_capwap_spinlock);

	core_status = nss_core_register_handler(if_num, nss_capwap_msg_handler, NULL);
	if (core_status != NSS_CORE_STATUS_SUCCESS) {
		nss_warning("%p: nss core register handler failed for if_num:%d with error :%d", nss_ctx, if_num, core_status);
		return NULL;
	}

	if (nss_capwap_instance_alloc(nss_ctx, if_num) == false) {
		nss_warning("%p: couldn't allocate tunnel  instance for if_num:%d", nss_ctx, if_num);
		return NULL;
	}

	nss_ctx->nss_top->if_ctx[if_num] = app_data;
	nss_ctx->nss_top->if_rx_callback[if_num] = cb;

	return nss_ctx;
}
EXPORT_SYMBOL(nss_capwap_data_register);

/*
 * nss_capwap_data_unregister()
 *	Unregister a data packet notifier with NSS FW
 */
bool nss_capwap_data_unregister(uint32_t if_num)
{
	struct nss_ctx_instance *nss_ctx;
	struct nss_capwap_handle *h;

	nss_ctx = nss_capwap_get_ctx();
	if (nss_capwap_verify_if_num(if_num) == false) {
		nss_warning("%p: data unregister received for invalid interface %d", nss_ctx, if_num);
		return false;
	}

	spin_lock(&nss_capwap_spinlock);
	/*
	 * It's the responsibility of caller to wait and call us again.
	 */
	if (nss_capwap_get_refcnt(if_num) != 0) {
		spin_unlock(&nss_capwap_spinlock);
		nss_warning("%p: notify unregister tunnel %d: has reference", nss_ctx, if_num);
		return false;
	}
	h = nss_capwap_hdl[if_num - NSS_DYNAMIC_IF_START];
	nss_capwap_hdl[if_num - NSS_DYNAMIC_IF_START] = NULL;
	spin_unlock(&nss_capwap_spinlock);

	(void) nss_core_unregister_handler(if_num);

	nss_ctx->nss_top->if_rx_callback[if_num] = NULL;
	nss_ctx->nss_top->if_ctx[if_num] = NULL;
	kfree(h);
	return true;
}
EXPORT_SYMBOL(nss_capwap_data_unregister);

/*
 * nss_capwap_get_ctx()
 *	Return a CAPWAP NSS context.
 */
struct nss_ctx_instance *nss_capwap_get_ctx()
{
	struct nss_ctx_instance *nss_ctx;

	nss_ctx = &nss_top_main.nss[nss_top_main.capwap_handler_id];
	return nss_ctx;
}
EXPORT_SYMBOL(nss_capwap_get_ctx);

/*
 * nss_capwap_init()
 *	Initializes CAPWAP. Gets called from nss_init.c
 */
void nss_capwap_init()
{
	memset(&nss_capwap_hdl, 0, sizeof(nss_capwap_hdl));
}

/*
 * nss_capwap_msg_init()
 *	Initialize capwap message.
 */
void nss_capwap_msg_init(struct nss_capwap_msg *ncm, uint16_t if_num, uint32_t type, uint32_t len,
				nss_capwap_msg_callback_t *cb, void *app_data)
{
	nss_cmn_msg_init(&ncm->cm, if_num, type, len, (void*)cb, app_data);
}
EXPORT_SYMBOL(nss_capwap_msg_init);