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  * 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
  24 #include <net/rtnetlink.h>
  25 #include <net/ieee802154_netdev.h>
  26 #include <net/mac802154.h>
  27 #include <net/cfg802154.h>
  28
  29 #include "ieee802154_i.h"
  30
  31 /* IEEE 802.15.4 transceivers can sleep during the xmit session, so process
  32  * packets through the workqueue.
  33  */
  34 struct wpan_xmit_cb {
  35         struct sk_buff *skb;
  36         struct work_struct work;
  37         struct ieee802154_local *local;
  38 };
  39
  40 static inline struct wpan_xmit_cb *wpan_xmit_cb(const struct sk_buff *skb)
  41 {
  42         BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct wpan_xmit_cb));
  43
  44         return (struct wpan_xmit_cb *)skb->cb;
  45 }
  46
  47 static void mac802154_xmit_worker(struct work_struct *work)
  48 {
  49         struct wpan_xmit_cb *cb = container_of(work, struct wpan_xmit_cb, work);
  50         struct ieee802154_local *local = cb->local;
  51         struct sk_buff *skb = cb->skb;
  52         int res;
  53
  54         rtnl_lock();
  55
  56         /* check if ifdown occurred while schedule */
  57         if (!netif_running(skb->dev))
  58                 goto err_tx;
  59
  60         res = local->ops->xmit_sync(&local->hw, skb);
  61         if (res)
  62                 goto err_tx;
  63
  64         ieee802154_xmit_complete(&local->hw, skb);
  65
  66         rtnl_unlock();
  67
  68         return;
  69
  70 err_tx:
  71         /* Restart the netif queue on each sub_if_data object. */
  72         ieee802154_wake_queue(&local->hw);
  73         rtnl_unlock();
  74         kfree_skb(skb);
  75         netdev_dbg(skb->dev, "transmission failed\n");
  76 }
  77
  78 static netdev_tx_t
  79 mac802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
  80 {
  81         struct wpan_xmit_cb *cb = wpan_xmit_cb(skb);
  82         int ret;
  83
  84         mac802154_monitors_rx(local, skb);
  85
  86         if (!(local->hw.flags & IEEE802154_HW_OMIT_CKSUM)) {
  87                 u16 crc = crc_ccitt(0, skb->data, skb->len);
  88                 u8 *data = skb_put(skb, 2);
  89
  90                 data[0] = crc & 0xff;
  91                 data[1] = crc >> 8;
  92         }
  93
  94         if (skb_cow_head(skb, local->hw.extra_tx_headroom))
  95                 goto err_tx;
  96
  97         /* Stop the netif queue on each sub_if_data object. */
  98         ieee802154_stop_queue(&local->hw);
  99
 100         /* async is priority, otherwise sync is fallback */
 101         if (local->ops->xmit_async) {
 102                 ret = local->ops->xmit_async(&local->hw, skb);
 103                 if (ret) {
 104                         ieee802154_wake_queue(&local->hw);
 105                         goto err_tx;
 106                 }
 107         } else {
 108                 INIT_WORK(&cb->work, mac802154_xmit_worker);
 109                 cb->skb = skb;
 110                 cb->local = local;
 111
 112                 queue_work(local->workqueue, &cb->work);
 113         }
 114
 115         return NETDEV_TX_OK;
 116
 117 err_tx:
 118         kfree_skb(skb);
 119         return NETDEV_TX_OK;
 120 }
 121
 122 netdev_tx_t mac802154_monitor_xmit(struct sk_buff *skb, struct net_device *dev)
 123 {
 124         struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
 125
 126         skb->skb_iif = dev->ifindex;
 127         dev->stats.tx_packets++;
 128         dev->stats.tx_bytes += skb->len;
 129
 130         return mac802154_tx(sdata->local, skb);
 131 }
 132
 133 netdev_tx_t mac802154_wpan_xmit(struct sk_buff *skb, struct net_device *dev)
 134 {
 135         struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
 136         int rc;
 137
 138         rc = mac802154_llsec_encrypt(&sdata->sec, skb);
 139         if (rc) {
 140                 netdev_warn(dev, "encryption failed: %i\n", rc);
 141                 kfree_skb(skb);
 142                 return NETDEV_TX_OK;
 143         }
 144
 145         skb->skb_iif = dev->ifindex;
 146         dev->stats.tx_packets++;
 147         dev->stats.tx_bytes += skb->len;
 148
 149         return mac802154_tx(sdata->local, skb);
 150 }