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authorAlexander Aring <alex.aring@gmail.com>2015-09-18 11:30:43 +0200
committerMarcel Holtmann <marcel@holtmann.org>2015-09-22 11:51:20 +0200
commit87a93e4eceb495f93e3f37b100334d2641765b6c (patch)
treed917662b1912a9788cdf431fc735b243e32dfb6c /net/mac802154
parent838b83d63d2909f9136f3030dc4fffa8230c31da (diff)
downloadlinux-stericsson-87a93e4eceb495f93e3f37b100334d2641765b6c.tar.gz
ieee802154: change needed headroom/tailroom
This patch cleanups needed_headroom, needed_tailroom and hard_header_len fields for wpan and lowpan interfaces. For wpan interfaces the worst case mac header len should be part of needed_headroom, currently this is set as hard_header_len, but hard_header_len should be set to the minimum header length which xmit call assumes and this is the minimum frame length of 802.15.4. The hard_header_len value will check inside send callbacl of AF_PACKET raw sockets. For lowpan interfaces, if fragmentation isn't needed the skb will call dev_hard_header for 802154 layer and queue it afterwards. This happens without new skb allocation, so we need the same headroom and tailroom lengths like 802154 inside 802154 6lowpan layer. At least we assume as minimum header length an ipv6 header size. Signed-off-by: Alexander Aring <alex.aring@gmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/mac802154')
-rw-r--r--net/mac802154/iface.c17
-rw-r--r--net/mac802154/tx.c3
2 files changed, 14 insertions, 6 deletions
diff --git a/net/mac802154/iface.c b/net/mac802154/iface.c
index 8afe26d72971..b5a0936ce514 100644
--- a/net/mac802154/iface.c
+++ b/net/mac802154/iface.c
@@ -537,8 +537,18 @@ static void ieee802154_if_setup(struct net_device *dev)
dev->addr_len = IEEE802154_EXTENDED_ADDR_LEN;
memset(dev->broadcast, 0xff, IEEE802154_EXTENDED_ADDR_LEN);
- dev->hard_header_len = MAC802154_FRAME_HARD_HEADER_LEN;
- dev->needed_tailroom = 2 + 16; /* FCS + MIC */
+ /* Let hard_header_len set to IEEE802154_MIN_HEADER_LEN. AF_PACKET
+ * will not send frames without any payload, but ack frames
+ * has no payload, so substract one that we can send a 3 bytes
+ * frame. The xmit callback assumes at least a hard header where two
+ * bytes fc and sequence field are set.
+ */
+ dev->hard_header_len = IEEE802154_MIN_HEADER_LEN - 1;
+ /* The auth_tag header is for security and places in private payload
+ * room of mac frame which stucks between payload and FCS field.
+ */
+ dev->needed_tailroom = IEEE802154_MAX_AUTH_TAG_LEN +
+ IEEE802154_FCS_LEN;
dev->mtu = IEEE802154_MTU;
dev->tx_queue_len = 300;
dev->flags = IFF_NOARP | IFF_BROADCAST;
@@ -617,7 +627,8 @@ ieee802154_if_add(struct ieee802154_local *local, const char *name,
if (!ndev)
return ERR_PTR(-ENOMEM);
- ndev->needed_headroom = local->hw.extra_tx_headroom;
+ ndev->needed_headroom = local->hw.extra_tx_headroom +
+ IEEE802154_MAX_HEADER_LEN;
ret = dev_alloc_name(ndev, ndev->name);
if (ret < 0)
diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c
index 7ed439172f30..66d7ecb7c56b 100644
--- a/net/mac802154/tx.c
+++ b/net/mac802154/tx.c
@@ -77,9 +77,6 @@ ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
put_unaligned_le16(crc, skb_put(skb, 2));
}
- if (skb_cow_head(skb, local->hw.extra_tx_headroom))
- goto err_tx;
-
/* Stop the netif queue on each sub_if_data object. */
ieee802154_stop_queue(&local->hw);