linux/net/mac802154/rx.c
alex.bluesman.smirnov@gmail.com 32bad7e30f mac802154: add wpan device-class support
Every real 802.15.4 transceiver, which works with software MAC layer,
can be classified as a wpan device in this stack. So the wpan device
implementation provides missing link in datapath between the device
drivers and the Linux network queue.

According to the IEEE 802.15.4 standard each packet can be one of the
following types:
 - beacon
 - MAC layer command
 - ACK
 - data

This patch adds support for the data packet-type only, but this is
enough to perform data transmission and receiving over radio.

Signed-off-by: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-26 21:06:11 -07:00

116 lines
3.0 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 */
}
mac802154_monitors_rx(priv, skb);
mac802154_wpans_rx(priv, skb);
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);