1/*
2 * Copyright 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 * Written by:
14 * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
15 * Sergey Lapin <slapin@ossfans.org>
16 * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
17 * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
18 */
19
20#include <linux/netdevice.h>
21#include <linux/if_arp.h>
22#include <linux/crc-ccitt.h>
23#include <asm/unaligned.h>
24
25#include <net/rtnetlink.h>
26#include <net/ieee802154_netdev.h>
27#include <net/mac802154.h>
28#include <net/cfg802154.h>
29
30#include "ieee802154_i.h"
31#include "driver-ops.h"
32
33/* IEEE 802.15.4 transceivers can sleep during the xmit session, so process
34 * packets through the workqueue.
35 */
36struct ieee802154_xmit_cb {
37	struct sk_buff *skb;
38	struct work_struct work;
39	struct ieee802154_local *local;
40};
41
42static struct ieee802154_xmit_cb ieee802154_xmit_cb;
43
44static void ieee802154_xmit_worker(struct work_struct *work)
45{
46	struct ieee802154_xmit_cb *cb =
47		container_of(work, struct ieee802154_xmit_cb, work);
48	struct ieee802154_local *local = cb->local;
49	struct sk_buff *skb = cb->skb;
50	struct net_device *dev = skb->dev;
51	int res;
52
53	rtnl_lock();
54
55	/* check if ifdown occurred while schedule */
56	if (!netif_running(dev))
57		goto err_tx;
58
59	res = drv_xmit_sync(local, skb);
60	if (res)
61		goto err_tx;
62
63	ieee802154_xmit_complete(&local->hw, skb, false);
64
65	dev->stats.tx_packets++;
66	dev->stats.tx_bytes += skb->len;
67
68	rtnl_unlock();
69
70	return;
71
72err_tx:
73	/* Restart the netif queue on each sub_if_data object. */
74	ieee802154_wake_queue(&local->hw);
75	rtnl_unlock();
76	kfree_skb(skb);
77	netdev_dbg(dev, "transmission failed\n");
78}
79
80static netdev_tx_t
81ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
82{
83	struct net_device *dev = skb->dev;
84	int ret;
85
86	if (!(local->hw.flags & IEEE802154_HW_TX_OMIT_CKSUM)) {
87		u16 crc = crc_ccitt(0, skb->data, skb->len);
88
89		put_unaligned_le16(crc, skb_put(skb, 2));
90	}
91
92	if (skb_cow_head(skb, local->hw.extra_tx_headroom))
93		goto err_tx;
94
95	/* Stop the netif queue on each sub_if_data object. */
96	ieee802154_stop_queue(&local->hw);
97
98	/* async is priority, otherwise sync is fallback */
99	if (local->ops->xmit_async) {
100		ret = drv_xmit_async(local, skb);
101		if (ret) {
102			ieee802154_wake_queue(&local->hw);
103			goto err_tx;
104		}
105
106		dev->stats.tx_packets++;
107		dev->stats.tx_bytes += skb->len;
108	} else {
109		INIT_WORK(&ieee802154_xmit_cb.work, ieee802154_xmit_worker);
110		ieee802154_xmit_cb.skb = skb;
111		ieee802154_xmit_cb.local = local;
112
113		queue_work(local->workqueue, &ieee802154_xmit_cb.work);
114	}
115
116	return NETDEV_TX_OK;
117
118err_tx:
119	kfree_skb(skb);
120	return NETDEV_TX_OK;
121}
122
123netdev_tx_t
124ieee802154_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev)
125{
126	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
127
128	skb->skb_iif = dev->ifindex;
129
130	return ieee802154_tx(sdata->local, skb);
131}
132
133netdev_tx_t
134ieee802154_subif_start_xmit(struct sk_buff *skb, struct net_device *dev)
135{
136	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
137	int rc;
138
139	rc = mac802154_llsec_encrypt(&sdata->sec, skb);
140	if (rc) {
141		netdev_warn(dev, "encryption failed: %i\n", rc);
142		kfree_skb(skb);
143		return NETDEV_TX_OK;
144	}
145
146	skb->skb_iif = dev->ifindex;
147
148	return ieee802154_tx(sdata->local, skb);
149}
150