linux/net/mac802154/rx.c
alex.bluesman.smirnov@gmail.com 1cd829c83e mac802154: RX data path
Main RX data path implementation between physical and mac layers.

Signed-off-by: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-16 15:16:44 -04:00

114 lines
2.9 KiB
C

/*
* Copyright (C) 2007-2012 Siemens AG
*
* 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.
*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Written by:
* Pavel Smolenskiy <pavel.smolenskiy@gmail.com>
* Maxim Gorbachyov <maxim.gorbachev@siemens.com>
* Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
* Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/workqueue.h>
#include <linux/netdevice.h>
#include <linux/crc-ccitt.h>
#include <net/mac802154.h>
#include <net/ieee802154_netdev.h>
#include "mac802154.h"
/* The IEEE 802.15.4 standard defines 4 MAC packet types:
* - beacon frame
* - MAC command frame
* - acknowledgement frame
* - data frame
*
* and only the data frame should be pushed to the upper layers, other types
* are just internal MAC layer management information. So only data packets
* are going to be sent to the networking queue, all other will be processed
* right here by using the device workqueue.
*/
struct rx_work {
struct sk_buff *skb;
struct work_struct work;
struct ieee802154_dev *dev;
u8 lqi;
};
static void
mac802154_subif_rx(struct ieee802154_dev *hw, struct sk_buff *skb, u8 lqi)
{
struct mac802154_priv *priv = mac802154_to_priv(hw);
mac_cb(skb)->lqi = lqi;
skb->protocol = htons(ETH_P_IEEE802154);
skb_reset_mac_header(skb);
BUILD_BUG_ON(sizeof(struct ieee802154_mac_cb) > sizeof(skb->cb));
if (!(priv->hw.flags & IEEE802154_HW_OMIT_CKSUM)) {
u16 crc;
if (skb->len < 2) {
pr_debug("got invalid frame\n");
goto out;
}
crc = crc_ccitt(0, skb->data, skb->len);
if (crc) {
pr_debug("CRC mismatch\n");
goto out;
}
skb_trim(skb, skb->len - 2); /* CRC */
}
out:
dev_kfree_skb(skb);
return;
}
static void mac802154_rx_worker(struct work_struct *work)
{
struct rx_work *rw = container_of(work, struct rx_work, work);
struct sk_buff *skb = rw->skb;
mac802154_subif_rx(rw->dev, skb, rw->lqi);
kfree(rw);
}
void
ieee802154_rx_irqsafe(struct ieee802154_dev *dev, struct sk_buff *skb, u8 lqi)
{
struct mac802154_priv *priv = mac802154_to_priv(dev);
struct rx_work *work;
if (!skb)
return;
work = kzalloc(sizeof(struct rx_work), GFP_ATOMIC);
if (!work)
return;
INIT_WORK(&work->work, mac802154_rx_worker);
work->skb = skb;
work->dev = dev;
work->lqi = lqi;
queue_work(priv->dev_workqueue, &work->work);
}
EXPORT_SYMBOL(ieee802154_rx_irqsafe);