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/ieee802154_netdev.h>
  25 #include <net/mac802154.h>
  26 #include <net/cfg802154.h>
  27
  28 #include "ieee802154_i.h"
  29
  30 /* IEEE 802.15.4 transceivers can sleep during the xmit session, so process
  31  * packets through the workqueue.
  32  */
  33 struct wpan_xmit_cb {
  34         struct sk_buff *skb;
  35         struct work_struct work;
  36         struct ieee802154_local *local;
  37         u8 chan;
  38         u8 page;
  39 };
  40
  41 static inline struct wpan_xmit_cb *wpan_xmit_cb(const struct sk_buff *skb)
  42 {
  43         BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct wpan_xmit_cb));
  44
  45         return (struct wpan_xmit_cb *)skb->cb;
  46 }
  47
  48 static void mac802154_xmit_worker(struct work_struct *work)
  49 {
  50         struct wpan_xmit_cb *cb = container_of(work, struct wpan_xmit_cb, work);
  51         struct ieee802154_local *local = cb->local;
  52         struct ieee802154_sub_if_data *sdata;
  53         struct sk_buff *skb = cb->skb;
  54         int res;
  55
  56         mutex_lock(&local->phy->pib_lock);
  57         if (local->phy->current_channel != cb->chan ||
  58             local->phy->current_page != cb->page) {
  59                 res = local->ops->set_channel(&local->hw, cb->page, cb->chan);
  60                 if (res) {
  61                         pr_debug("set_channel failed\n");
  62                         goto out;
  63                 }
  64
  65                 local->phy->current_channel = cb->chan;
  66                 local->phy->current_page = cb->page;
  67         }
  68
  69         res = local->ops->xmit(&local->hw, skb);
  70         if (res)
  71                 pr_debug("transmission failed\n");
  72
  73 out:
  74         mutex_unlock(&local->phy->pib_lock);
  75
  76         /* Restart the netif queue on each sub_if_data object. */
  77         rcu_read_lock();
  78         list_for_each_entry_rcu(sdata, &local->interfaces, list)
  79                 netif_wake_queue(sdata->dev);
  80         rcu_read_unlock();
  81
  82         dev_kfree_skb(skb);
  83 }
  84
  85 static netdev_tx_t mac802154_tx(struct ieee802154_local *local,
  86                                 struct sk_buff *skb, u8 page, u8 chan)
  87 {
  88         struct ieee802154_sub_if_data *sdata;
  89         struct wpan_xmit_cb *cb = wpan_xmit_cb(skb);
  90
  91         if (!(local->phy->channels_supported[page] & (1 << chan))) {
  92                 WARN_ON(1);
  93                 goto err_tx;
  94         }
  95
  96         mac802154_monitors_rx(local, skb);
  97
  98         if (!(local->hw.flags & IEEE802154_HW_OMIT_CKSUM)) {
  99                 u16 crc = crc_ccitt(0, skb->data, skb->len);
 100                 u8 *data = skb_put(skb, 2);
 101
 102                 data[0] = crc & 0xff;
 103                 data[1] = crc >> 8;
 104         }
 105
 106         if (skb_cow_head(skb, local->hw.extra_tx_headroom))
 107                 goto err_tx;
 108
 109         /* Stop the netif queue on each sub_if_data object. */
 110         rcu_read_lock();
 111         list_for_each_entry_rcu(sdata, &local->interfaces, list)
 112                 netif_stop_queue(sdata->dev);
 113         rcu_read_unlock();
 114
 115         INIT_WORK(&cb->work, mac802154_xmit_worker);
 116         cb->skb = skb;
 117         cb->local = local;
 118         cb->page = page;
 119         cb->chan = chan;
 120
 121         queue_work(local->workqueue, &cb->work);
 122
 123         return NETDEV_TX_OK;
 124
 125 err_tx:
 126         kfree_skb(skb);
 127         return NETDEV_TX_OK;
 128 }
 129
 130 netdev_tx_t mac802154_monitor_xmit(struct sk_buff *skb, struct net_device *dev)
 131 {
 132         struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
 133         u8 chan, page;
 134
 135         /* FIXME: locking */
 136         chan = sdata->local->phy->current_channel;
 137         page = sdata->local->phy->current_page;
 138
 139         if (chan == MAC802154_CHAN_NONE) /* not initialized */
 140                 return NETDEV_TX_OK;
 141
 142         if (WARN_ON(page >= WPAN_NUM_PAGES) ||
 143             WARN_ON(chan >= WPAN_NUM_CHANNELS))
 144                 return NETDEV_TX_OK;
 145
 146         skb->skb_iif = dev->ifindex;
 147         dev->stats.tx_packets++;
 148         dev->stats.tx_bytes += skb->len;
 149
 150         return mac802154_tx(sdata->local, skb, page, chan);
 151 }
 152
 153 netdev_tx_t mac802154_wpan_xmit(struct sk_buff *skb, struct net_device *dev)
 154 {
 155         struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
 156         u8 chan, page;
 157         int rc;
 158
 159         spin_lock_bh(&sdata->mib_lock);
 160         chan = sdata->chan;
 161         page = sdata->page;
 162         spin_unlock_bh(&sdata->mib_lock);
 163
 164         if (chan == MAC802154_CHAN_NONE ||
 165             page >= WPAN_NUM_PAGES ||
 166             chan >= WPAN_NUM_CHANNELS) {
 167                 kfree_skb(skb);
 168                 return NETDEV_TX_OK;
 169         }
 170
 171         rc = mac802154_llsec_encrypt(&sdata->sec, skb);
 172         if (rc) {
 173                 pr_warn("encryption failed: %i\n", rc);
 174                 kfree_skb(skb);
 175                 return NETDEV_TX_OK;
 176         }
 177
 178         skb->skb_iif = dev->ifindex;
 179         dev->stats.tx_packets++;
 180         dev->stats.tx_bytes += skb->len;
 181
 182         return mac802154_tx(sdata->local, skb, page, chan);
 183 }