linux-stable/net/mac802154/tx.c
Alexander Aring b40988c438 ieee802154: change mtu size behaviour
This patch changes the mtu size of 802.15.4 interfaces. The current
setting is the meaning of the maximum transport unit with mac header,
which is 127 bytes according 802.15.4. The linux meaning of the mtu size
field is the maximum payload of a mac frame. Like in ethernet, which is
1500 bytes.

We have dynamic length of mac frames in 802.15.4, this is why we assume
the minimum header length which is hard_header_len. This contains fc and
sequence fields. These can evaluated by driver layer without additional
checks. We currently don't support to set the FCS from userspace, so we
need to subtract this from mtu size as well.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2015-09-30 13:21:32 +02:00

135 lines
3.2 KiB
C

/*
* Copyright 2007-2012 Siemens AG
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Written by:
* Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
* Sergey Lapin <slapin@ossfans.org>
* Maxim Gorbachyov <maxim.gorbachev@siemens.com>
* Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
*/
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/crc-ccitt.h>
#include <asm/unaligned.h>
#include <net/rtnetlink.h>
#include <net/ieee802154_netdev.h>
#include <net/mac802154.h>
#include <net/cfg802154.h>
#include "ieee802154_i.h"
#include "driver-ops.h"
void ieee802154_xmit_worker(struct work_struct *work)
{
struct ieee802154_local *local =
container_of(work, struct ieee802154_local, tx_work);
struct sk_buff *skb = local->tx_skb;
struct net_device *dev = skb->dev;
int res;
rtnl_lock();
/* check if ifdown occurred while schedule */
if (!netif_running(dev))
goto err_tx;
res = drv_xmit_sync(local, skb);
if (res)
goto err_tx;
ieee802154_xmit_complete(&local->hw, skb, false);
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;
rtnl_unlock();
return;
err_tx:
/* Restart the netif queue on each sub_if_data object. */
ieee802154_wake_queue(&local->hw);
rtnl_unlock();
kfree_skb(skb);
netdev_dbg(dev, "transmission failed\n");
}
static netdev_tx_t
ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
int ret;
if (!(local->hw.flags & IEEE802154_HW_TX_OMIT_CKSUM)) {
u16 crc = crc_ccitt(0, skb->data, skb->len);
put_unaligned_le16(crc, skb_put(skb, 2));
}
/* Stop the netif queue on each sub_if_data object. */
ieee802154_stop_queue(&local->hw);
/* async is priority, otherwise sync is fallback */
if (local->ops->xmit_async) {
ret = drv_xmit_async(local, skb);
if (ret) {
ieee802154_wake_queue(&local->hw);
goto err_tx;
}
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;
} else {
local->tx_skb = skb;
queue_work(local->workqueue, &local->tx_work);
}
return NETDEV_TX_OK;
err_tx:
kfree_skb(skb);
return NETDEV_TX_OK;
}
netdev_tx_t
ieee802154_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
skb->skb_iif = dev->ifindex;
return ieee802154_tx(sdata->local, skb);
}
netdev_tx_t
ieee802154_subif_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
int rc;
/* TODO we should move it to wpan_dev_hard_header and dev_hard_header
* functions. The reason is wireshark will show a mac header which is
* with security fields but the payload is not encrypted.
*/
rc = mac802154_llsec_encrypt(&sdata->sec, skb);
if (rc) {
netdev_warn(dev, "encryption failed: %i\n", rc);
kfree_skb(skb);
return NETDEV_TX_OK;
}
skb->skb_iif = dev->ifindex;
return ieee802154_tx(sdata->local, skb);
}