1/*
2 * Copyright (C) 2007-2012 Siemens AG
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 *
17 * Written by:
18 * Pavel Smolenskiy <pavel.smolenskiy@gmail.com>
19 * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
20 * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
21 * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
22 */
23
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/workqueue.h>
27#include <linux/netdevice.h>
28#include <linux/crc-ccitt.h>
29
30#include <net/mac802154.h>
31#include <net/ieee802154_netdev.h>
32
33#include "mac802154.h"
34
35/* The IEEE 802.15.4 standard defines 4 MAC packet types:
36 * - beacon frame
37 * - MAC command frame
38 * - acknowledgement frame
39 * - data frame
40 *
41 * and only the data frame should be pushed to the upper layers, other types
42 * are just internal MAC layer management information. So only data packets
43 * are going to be sent to the networking queue, all other will be processed
44 * right here by using the device workqueue.
45 */
46struct rx_work {
47	struct sk_buff *skb;
48	struct work_struct work;
49	struct ieee802154_dev *dev;
50	u8 lqi;
51};
52
53static void
54mac802154_subif_rx(struct ieee802154_dev *hw, struct sk_buff *skb, u8 lqi)
55{
56	struct mac802154_priv *priv = mac802154_to_priv(hw);
57
58	mac_cb(skb)->lqi = lqi;
59	skb->protocol = htons(ETH_P_IEEE802154);
60	skb_reset_mac_header(skb);
61
62	if (!(priv->hw.flags & IEEE802154_HW_OMIT_CKSUM)) {
63		u16 crc;
64
65		if (skb->len < 2) {
66			pr_debug("got invalid frame\n");
67			goto fail;
68		}
69		crc = crc_ccitt(0, skb->data, skb->len);
70		if (crc) {
71			pr_debug("CRC mismatch\n");
72			goto fail;
73		}
74		skb_trim(skb, skb->len - 2); /* CRC */
75	}
76
77	mac802154_monitors_rx(priv, skb);
78	mac802154_wpans_rx(priv, skb);
79
80	return;
81
82fail:
83	kfree_skb(skb);
84}
85
86static void mac802154_rx_worker(struct work_struct *work)
87{
88	struct rx_work *rw = container_of(work, struct rx_work, work);
89
90	mac802154_subif_rx(rw->dev, rw->skb, rw->lqi);
91	kfree(rw);
92}
93
94void
95ieee802154_rx_irqsafe(struct ieee802154_dev *dev, struct sk_buff *skb, u8 lqi)
96{
97	struct mac802154_priv *priv = mac802154_to_priv(dev);
98	struct rx_work *work;
99
100	if (!skb)
101		return;
102
103	work = kzalloc(sizeof(*work), GFP_ATOMIC);
104	if (!work)
105		return;
106
107	INIT_WORK(&work->work, mac802154_rx_worker);
108	work->skb = skb;
109	work->dev = dev;
110	work->lqi = lqi;
111
112	queue_work(priv->dev_workqueue, &work->work);
113}
114EXPORT_SYMBOL(ieee802154_rx_irqsafe);
115