alistair23-linux/net/mac802154/rx.c
Phoebe Buckheister 2d3b5b0a90 mac802154: don't deliver packets to devices that are down
Only one WPAN devices can be active at any given time, so only deliver
packets to that one interface that is actually up. Multiple monitors may
be up at any given time, but we don't have to deliver to monitors that
are down either.

Signed-off-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-11 12:10:19 -07:00

116 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);
if (!(priv->hw.flags & IEEE802154_HW_OMIT_CKSUM)) {
u16 crc;
if (skb->len < 2) {
pr_debug("got invalid frame\n");
goto fail;
}
crc = crc_ccitt(0, skb->data, skb->len);
if (crc) {
pr_debug("CRC mismatch\n");
goto fail;
}
skb_trim(skb, skb->len - 2); /* CRC */
}
mac802154_monitors_rx(priv, skb);
mac802154_wpans_rx(priv, skb);
return;
fail:
kfree_skb(skb);
}
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);