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 #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  */
  36 struct ieee802154_xmit_cb {
  37         struct sk_buff *skb;
  38         struct work_struct work;
  39         struct ieee802154_local *local;
  40 };
  41
  42 static struct ieee802154_xmit_cb ieee802154_xmit_cb;
  43
  44 static 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
  72 err_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
  80 static netdev_tx_t
  81 ieee802154_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
 118 err_tx:
 119         kfree_skb(skb);
 120         return NETDEV_TX_OK;
 121 }
 122
 123 netdev_tx_t
 124 ieee802154_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
 133 netdev_tx_t
 134 ieee802154_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 }