netfilter: nfnetlink_log: fix NLA_PUT macro removal bug
[linux-3.10.git] / net / mac802154 / tx.c
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  * 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  * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
19  * Sergey Lapin <slapin@ossfans.org>
20  * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
21  * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
22  */
23
24 #include <linux/netdevice.h>
25 #include <linux/if_arp.h>
26 #include <linux/crc-ccitt.h>
27
28 #include <net/mac802154.h>
29 #include <net/wpan-phy.h>
30
31 #include "mac802154.h"
32
33 /* IEEE 802.15.4 transceivers can sleep during the xmit session, so process
34  * packets through the workqueue.
35  */
36 struct xmit_work {
37         struct sk_buff *skb;
38         struct work_struct work;
39         struct mac802154_priv *priv;
40         u8 chan;
41         u8 page;
42         u8 xmit_attempts;
43 };
44
45 static void mac802154_xmit_worker(struct work_struct *work)
46 {
47         struct xmit_work *xw = container_of(work, struct xmit_work, work);
48         int res;
49
50         mutex_lock(&xw->priv->phy->pib_lock);
51         if (xw->priv->phy->current_channel != xw->chan ||
52             xw->priv->phy->current_page != xw->page) {
53                 res = xw->priv->ops->set_channel(&xw->priv->hw,
54                                                   xw->page,
55                                                   xw->chan);
56                 if (res) {
57                         pr_debug("set_channel failed\n");
58                         goto out;
59                 }
60         }
61
62         res = xw->priv->ops->xmit(&xw->priv->hw, xw->skb);
63
64 out:
65         mutex_unlock(&xw->priv->phy->pib_lock);
66
67         if (res) {
68                 if (xw->xmit_attempts++ < MAC802154_MAX_XMIT_ATTEMPTS) {
69                         queue_work(xw->priv->dev_workqueue, &xw->work);
70                         return;
71                 } else
72                         pr_debug("transmission failed for %d times",
73                                  MAC802154_MAX_XMIT_ATTEMPTS);
74         }
75
76         dev_kfree_skb(xw->skb);
77
78         kfree(xw);
79 }
80
81 netdev_tx_t mac802154_tx(struct mac802154_priv *priv, struct sk_buff *skb,
82                          u8 page, u8 chan)
83 {
84         struct xmit_work *work;
85
86         if (!(priv->phy->channels_supported[page] & (1 << chan))) {
87                 WARN_ON(1);
88                 return NETDEV_TX_OK;
89         }
90
91         mac802154_monitors_rx(mac802154_to_priv(&priv->hw), skb);
92
93         if (!(priv->hw.flags & IEEE802154_HW_OMIT_CKSUM)) {
94                 u16 crc = crc_ccitt(0, skb->data, skb->len);
95                 u8 *data = skb_put(skb, 2);
96                 data[0] = crc & 0xff;
97                 data[1] = crc >> 8;
98         }
99
100         if (skb_cow_head(skb, priv->hw.extra_tx_headroom)) {
101                 dev_kfree_skb(skb);
102                 return NETDEV_TX_OK;
103         }
104
105         work = kzalloc(sizeof(struct xmit_work), GFP_ATOMIC);
106         if (!work)
107                 return NETDEV_TX_BUSY;
108
109         INIT_WORK(&work->work, mac802154_xmit_worker);
110         work->skb = skb;
111         work->priv = priv;
112         work->page = page;
113         work->chan = chan;
114         work->xmit_attempts = 0;
115
116         queue_work(priv->dev_workqueue, &work->work);
117
118         return NETDEV_TX_OK;
119 }