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mac802154: rx: simplify crc receive handling

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This patch change the actual crc handling while receive. Currently the
IEEE802154_HW_RX_OMIT_CKSUM flag is used to filter a frame with a bad crc.
This patch changes the behaviour of IEEE802154_HW_RX_OMIT_CKSUM to add a
crc while receiving for the monitor interface. After monitor receiving
we remove the crc for frame parsing. This affect the driver layer
because all drivers sets IEEE802154_HW_RX_OMIT_CKSUM and deliver without
checksum.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Alexander Aring 2014-10-29 21:34:36 +01:00 committed by Marcel Holtmann
parent 08c511a733
commit b7889497d3
1 changed files with 12 additions and 22 deletions
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34
net/mac802154/rx.c
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@ -21,6 +21,7 @@
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/crc-ccitt.h>
#include <asm/unaligned.h>
#include <net/mac802154.h>
#include <net/ieee802154_netdev.h>
@ -225,8 +226,6 @@ ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
{
struct sk_buff *skb2;
struct ieee802154_sub_if_data *sdata;
u16 crc = crc_ccitt(0, skb->data, skb->len);
u8 *data;
skb_reset_mac_header(skb);
skb->ip_summed = CHECKSUM_UNNECESSARY;
@ -241,9 +240,6 @@ ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
skb2 = skb_clone(skb, GFP_ATOMIC);
skb2->dev = sdata->dev;
skb2->pkt_type = PACKET_HOST;
data = skb_put(skb2, 2);
data[0] = crc & 0xff;
data[1] = crc >> 8;
netif_rx_ni(skb2);
}
@ -255,32 +251,26 @@ void ieee802154_rx(struct ieee802154_hw *hw, struct sk_buff *skb)
WARN_ON_ONCE(softirq_count() == 0);
if (!(local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM)) {
u16 crc;
/* TODO: When a transceiver omits the checksum here, we
* add an own calculated one. This is currently an ugly
* solution because the monitor needs a crc here.
*/
if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
u16 crc = crc_ccitt(0, skb->data, skb->len);
if (skb->len < 2) {
pr_debug("got invalid frame\n");
goto fail;
}
crc = crc_ccitt(0, skb->data, skb->len);
if (crc) {
pr_debug("CRC mismatch\n");
goto fail;
}
skb_trim(skb, skb->len - 2); /* CRC */
put_unaligned_le16(crc, skb_put(skb, 2));
}
rcu_read_lock();
ieee802154_monitors_rx(local, skb);
/* remove crc */
skb_trim(skb, skb->len - 2);
__ieee802154_rx_handle_packet(local, skb);
rcu_read_unlock();
return;
fail:
kfree_skb(skb);
}
EXPORT_SYMBOL(ieee802154_rx);