batman-adv: use eth_hdr() instead of skb->data in interface_tx path
Commit Message
Using eth_hdr() instead of skb->data avoids some ugly type casts.
I wasn't able to reproduce the skb ether header pointer mismatch
mentioned in batadv_bla_tx() on a 3.11 kernel with a vlan on top of
bat0 and therefore removed the according skb_reset_mac_header()
call, too. Nevertheless I've added a check to the beginning of
batadv_interface_tx() as I guess there might potentially be some device
drivers not being that nice.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
---
bridge_loop_avoidance.c | 3 ---
soft-interface.c | 12 +++++++++---
2 files changed, 9 insertions(+), 6 deletions(-)
@@ -1535,9 +1535,6 @@ int batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb,
if (!atomic_read(&bat_priv->bridge_loop_avoidance))
goto allow;
- /* in VLAN case, the mac header might not be set. */
- skb_reset_mac_header(skb);
-
if (batadv_bla_process_claim(bat_priv, primary_if, skb))
goto handled;
@@ -176,7 +176,13 @@ static int batadv_interface_tx(struct sk_buff *skb,
soft_iface->trans_start = jiffies;
vid = batadv_get_vid(skb, 0);
- ethhdr = (struct ethhdr *)skb->data;
+
+ if (skb->data != eth_hdr(skb)) {
+ pr_warn("Upper device did not set the ethernet header pointer correctly - adjusting\n");
+ skb_reset_mac_header(skb);
+ }
+
+ ethhdr = eth_hdr(skb);
switch (ntohs(ethhdr->h_proto)) {
case ETH_P_8021Q:
@@ -194,7 +200,7 @@ static int batadv_interface_tx(struct sk_buff *skb,
goto dropped;
/* skb->data might have been reallocated by batadv_bla_tx() */
- ethhdr = (struct ethhdr *)skb->data;
+ ethhdr = eth_hdr(skb);
/* Register the client MAC in the transtable */
if (!is_multicast_ether_addr(ethhdr->h_source)) {
@@ -230,7 +236,7 @@ static int batadv_interface_tx(struct sk_buff *skb,
/* skb->data may have been modified by
* batadv_gw_dhcp_recipient_get()
*/
- ethhdr = (struct ethhdr *)skb->data;
+ ethhdr = eth_hdr(skb);
/* if gw_mode is on, broadcast any non-DHCP message.
* All the DHCP packets are going to be sent as unicast
*/