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 void ieee802154_xmit_worker(struct work_struct *work)
  34 {
  35         struct ieee802154_local *local =
  36                 container_of(work, struct ieee802154_local, tx_work);
  37         struct sk_buff *skb = local->tx_skb;
  38         struct net_device *dev = skb->dev;
  39         int res;
  40
  41         res = drv_xmit_sync(local, skb);
  42         if (res)
  43                 goto err_tx;
  44
  45         ieee802154_xmit_complete(&local->hw, skb, false);
  46
  47         dev->stats.tx_packets++;
  48         dev->stats.tx_bytes += skb->len;
  49
  50         return;
  51
  52 err_tx:
  53         /* Restart the netif queue on each sub_if_data object. */
  54         ieee802154_wake_queue(&local->hw);
  55         kfree_skb(skb);
  56         netdev_dbg(dev, "transmission failed\n");
  57 }
  58
  59 static netdev_tx_t
  60 ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
  61 {
  62         struct net_device *dev = skb->dev;
  63         int ret;
  64
  65         if (!(local->hw.flags & IEEE802154_HW_TX_OMIT_CKSUM)) {
  66                 struct sk_buff *nskb;
  67                 u16 crc;
  68
  69                 if (unlikely(skb_tailroom(skb) < IEEE802154_FCS_LEN)) {
  70                         nskb = skb_copy_expand(skb, 0, IEEE802154_FCS_LEN,
  71                                                GFP_ATOMIC);
  72                         if (likely(nskb)) {
  73                                 consume_skb(skb);
  74                                 skb = nskb;
  75                         } else {
  76                                 goto err_tx;
  77                         }
  78                 }
  79
  80                 crc = crc_ccitt(0, skb->data, skb->len);
  81                 put_unaligned_le16(crc, skb_put(skb, 2));
  82         }
  83
  84         /* Stop the netif queue on each sub_if_data object. */
  85         ieee802154_stop_queue(&local->hw);
  86
  87         /* async is priority, otherwise sync is fallback */
  88         if (local->ops->xmit_async) {
  89                 ret = drv_xmit_async(local, skb);
  90                 if (ret) {
  91                         ieee802154_wake_queue(&local->hw);
  92                         goto err_tx;
  93                 }
  94
  95                 dev->stats.tx_packets++;
  96                 dev->stats.tx_bytes += skb->len;
  97         } else {
  98                 local->tx_skb = skb;
  99                 queue_work(local->workqueue, &local->tx_work);
 100         }
 101
 102         return NETDEV_TX_OK;
 103
 104 err_tx:
 105         kfree_skb(skb);
 106         return NETDEV_TX_OK;
 107 }
 108
 109 netdev_tx_t
 110 ieee802154_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev)
 111 {
 112         struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
 113
 114         skb->skb_iif = dev->ifindex;
 115
 116         return ieee802154_tx(sdata->local, skb);
 117 }
 118
 119 netdev_tx_t
 120 ieee802154_subif_start_xmit(struct sk_buff *skb, struct net_device *dev)
 121 {
 122         struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
 123         int rc;
 124
 125         /* TODO we should move it to wpan_dev_hard_header and dev_hard_header
 126          * functions. The reason is wireshark will show a mac header which is
 127          * with security fields but the payload is not encrypted.
 128          */
 129         rc = mac802154_llsec_encrypt(&sdata->sec, skb);
 130         if (rc) {
 131                 netdev_warn(dev, "encryption failed: %i\n", rc);
 132                 kfree_skb(skb);
 133                 return NETDEV_TX_OK;
 134         }
 135
 136         skb->skb_iif = dev->ifindex;
 137
 138         return ieee802154_tx(sdata->local, skb);
 139 }