[34-longterm 089/247] bonding/vlan: Avoid mangled NAs on slaves without VLAN tag insertion

Paul Gortmaker
2011-06-23T18:20:21Z

From: Ben Hutchings <bhutchings@solarflare.com>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
-------------------

This is related to commit f88a4a9b65a6f3422b81be995535d0e69df11bb8
upstream, but the bug cannot be properly fixed without the other
changes to VLAN tagging in 2.6.37.

bond_na_send() attempts to insert a VLAN tag in between building and
sending packets of the respective formats. If the slave does not
implement hardware VLAN tag insertion then vlan_put_tag() will mangle
the network-layer header because the Ethernet header is not present at
this point (unlike in bond_arp_send()).

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
drivers/net/bonding/bond_ipv6.c | 9 ++++++++-
1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/drivers/net/bonding/bond_ipv6.c b/drivers/net/bonding/bond_ipv6.c
index 6dd64cf..a131d6f 100644
--- a/drivers/net/bonding/bond_ipv6.c
+++ b/drivers/net/bonding/bond_ipv6.c
@@ -69,6 +69,13 @@ static void bond_na_send(struct net_device *slave_dev,
};
struct sk_buff *skb;

+ /* The Ethernet header is built in ndisc_send_skb(), not
+ * ndisc_build_skb(), so we cannot insert a VLAN tag. Only an
+ * out-of-line tag inserted by the hardware will work.
+ */
+ if (vlan_id && !(slave_dev->features & NETIF_F_HW_VLAN_TX))
+ return;
+
icmp6h.icmp6_router = router;
icmp6h.icmp6_solicited = 0;
icmp6h.icmp6_override = 1;
@@ -87,7 +94,7 @@ static void bond_na_send(struct net_device *slave_dev,
}

if (vlan_id) {
- skb = vlan_put_tag(skb, vlan_id);
+ skb = __vlan_hwaccel_put_tag(skb, vlan_id);
if (!skb) {
pr_err("failed to insert VLAN tag\n");
return;
--
1.7.4.4