3 files changed, 22 insertions, 6 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);
 
diff --git a/net/ieee802154/6lowpan/tx.c b/net/ieee802154/6lowpan/tx.c
index 6067e064a3fe..7e0563eaea98 100644
--- a/net/ieee802154/6lowpan/tx.c
+++ b/net/ieee802154/6lowpan/tx.c
@@ -10,6 +10,7 @@
 
 #include <net/6lowpan.h>
 #include <net/ieee802154_netdev.h>
+#include <net/mac802154.h>
 
 #include "6lowpan_i.h"
 
@@ -36,6 +37,13 @@ lowpan_addr_info *lowpan_skb_priv(const struct sk_buff *skb)
 			sizeof(struct lowpan_addr_info));
 }
 
+/* This callback will be called from AF_PACKET and IPv6 stack, the AF_PACKET
+ * sockets gives an 8 byte array for addresses only!
+ *
+ * TODO I think AF_PACKET DGRAM (sending/receiving) RAW (sending) makes no
+ * sense here. We should disable it, the right use-case would be AF_INET6
+ * RAW/DGRAM sockets.
+ */
 int lowpan_header_create(struct sk_buff *skb, struct net_device *ldev,
 			 unsigned short type, const void *_daddr,
 			 const void *_saddr, unsigned int len)
@@ -77,13 +85,13 @@ lowpan_alloc_frag(struct sk_buff *skb, int size,
 	struct sk_buff *frag;
 	int rc;
 
-	frag = alloc_skb(wdev->hard_header_len + wdev->needed_tailroom + size,
+	frag = alloc_skb(wdev->needed_headroom + wdev->needed_tailroom + size,
 			 GFP_ATOMIC);
 
 	if (likely(frag)) {
 		frag->dev = wdev;
 		frag->priority = skb->priority;
-		skb_reserve(frag, wdev->hard_header_len);
+		skb_reserve(frag, wdev->needed_headroom);
 		skb_reset_network_header(frag);
 		*mac_cb(frag) = *mac_cb(skb);
 
diff --git a/net/ieee802154/header_ops.c b/net/ieee802154/header_ops.c
index d8443b057022..c7439f0fbbdf 100644
--- a/net/ieee802154/header_ops.c
+++ b/net/ieee802154/header_ops.c
@@ -85,7 +85,7 @@ ieee802154_hdr_push_sechdr(u8 *buf, const struct ieee802154_sechdr *hdr)
 int
 ieee802154_hdr_push(struct sk_buff *skb, struct ieee802154_hdr *hdr)
 {
-	u8 buf[MAC802154_FRAME_HARD_HEADER_LEN];
+	u8 buf[IEEE802154_MAX_HEADER_LEN];
 	int pos = 2;
 	int rc;
 	struct ieee802154_hdr_fc *fc = &hdr->fc;