ieee802154: introduce wpan_dev_header_ops

The current header_ops callback structure of net device are used mostly
from 802.15.4 upper-layers. Because this callback structure is a very
generic one, which is also used by e.g. DGRAM AF_PACKET sockets, we
can't make this callback structure 802.15.4 specific which is currently
is.

I saw the smallest "constraint" for calling this callback with
dev_hard_header/dev_parse_header by AF_PACKET which assign a 8 byte
array for address void pointers. Currently 802.15.4 specific protocols
like af802154 and 6LoWPAN will assign the "struct ieee802154_addr" as
these parameters which is greater than 8 bytes. The current callback
implementation for header_ops.create assumes always a complete
"struct ieee802154_addr" which AF_PACKET can't never handled and is
greater than 8 bytes.

For that reason we introduce now a "generic" create/parse header_ops
callback which allows handling with intra-pan extended addresses only.
This allows a small use-case with AF_PACKET to send "somehow" a valid
dataframe over DGRAM.

To keeping the current dev_hard_header behaviour we introduce a similar
callback structure "wpan_dev_header_ops" which contains 802.15.4 specific
upper-layer header creation functionality, which can be called by
wpan_dev_hard_header.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

2 files changed, 6 insertions, 6 deletions

diff --git a/net/ieee802154/6lowpan/tx.c b/net/ieee802154/6lowpan/tx.c
index 54939d0..6067e06 100644
--- a/net/ieee802154/6lowpan/tx.c
+++ b/net/ieee802154/6lowpan/tx.c
@@ -87,8 +87,8 @@ lowpan_alloc_frag(struct sk_buff *skb, int size,
 		skb_reset_network_header(frag);
 		*mac_cb(frag) = *mac_cb(skb);
 
-		rc = dev_hard_header(frag, wdev, 0, &master_hdr->dest,
-				     &master_hdr->source, size);
+		rc = wpan_dev_hard_header(frag, wdev, &master_hdr->dest,
+					  &master_hdr->source, size);
 		if (rc < 0) {
 			kfree_skb(frag);
 			return ERR_PTR(rc);
@@ -228,8 +228,8 @@ static int lowpan_header(struct sk_buff *skb, struct net_device *ldev,
 		cb->ackreq = wpan_dev->ackreq;
 	}
 
-	return dev_hard_header(skb, lowpan_dev_info(ldev)->wdev, ETH_P_IPV6,
-			       (void *)&da, (void *)&sa, 0);
+	return wpan_dev_hard_header(skb, lowpan_dev_info(ldev)->wdev, &da, &sa,
+				    0);
 }
 
 netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev)
diff --git a/net/ieee802154/socket.c b/net/ieee802154/socket.c
index b6eacf3..be77f21 100644
--- a/net/ieee802154/socket.c
+++ b/net/ieee802154/socket.c
@@ -676,8 +676,8 @@ static int dgram_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 	cb->seclevel = ro->seclevel;
 	cb->seclevel_override = ro->seclevel_override;
 
-	err = dev_hard_header(skb, dev, ETH_P_IEEE802154, &dst_addr,
-			      ro->bound ? &ro->src_addr : NULL, size);
+	err = wpan_dev_hard_header(skb, dev, &dst_addr,
+				   ro->bound ? &ro->src_addr : NULL, size);
 	if (err < 0)
 		goto out_skb;