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Diffstat (limited to 'net/ieee802154/6lowpan/core.c')
-rw-r--r--net/ieee802154/6lowpan/core.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c
index 9f0cfa598e3a..44420ed95574 100644
--- a/net/ieee802154/6lowpan/core.c
+++ b/net/ieee802154/6lowpan/core.c
@@ -104,9 +104,8 @@ static void lowpan_setup(struct net_device *ldev)
ldev->addr_len = IEEE802154_ADDR_LEN;
memset(ldev->broadcast, 0xff, IEEE802154_ADDR_LEN);
ldev->type = ARPHRD_6LOWPAN;
- /* Frame Control + Sequence Number + Address fields + Security Header */
- ldev->hard_header_len = 2 + 1 + 20 + 14;
- ldev->needed_tailroom = 2; /* FCS */
+ /* We need an ipv6hdr as minimum len when calling xmit */
+ ldev->hard_header_len = sizeof(struct ipv6hdr);
ldev->mtu = IPV6_MIN_MTU;
ldev->priv_flags |= IFF_NO_QUEUE;
ldev->flags = IFF_BROADCAST | IFF_MULTICAST;
@@ -156,6 +155,15 @@ static int lowpan_newlink(struct net *src_net, struct net_device *ldev,
lowpan_dev_info(ldev)->wdev = wdev;
/* Set the lowpan hardware address to the wpan hardware address. */
memcpy(ldev->dev_addr, wdev->dev_addr, IEEE802154_ADDR_LEN);
+ /* We need headroom for possible wpan_dev_hard_header call and tailroom
+ * for encryption/fcs handling. The lowpan interface will replace
+ * the IPv6 header with 6LoWPAN header. At worst case the 6LoWPAN
+ * header has LOWPAN_IPHC_MAX_HEADER_LEN more bytes than the IPv6
+ * header.
+ */
+ ldev->needed_headroom = LOWPAN_IPHC_MAX_HEADER_LEN +
+ wdev->needed_headroom;
+ ldev->needed_tailroom = wdev->needed_tailroom;
lowpan_netdev_setup(ldev, LOWPAN_LLTYPE_IEEE802154);