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bonding/vlan: Avoid mangled NAs on slaves without VLAN tag insertion

PATCH In review Ben Hutchings 3 participants 3 messages Feb 7, 2011 – Feb 16, 2011

Subsystems (3)
Networking Network drivers Bonding driver
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Ben Hutchings

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PATCH 1/1 bonding/vlan: Avoid mangled NAs on slaves without VLAN tag insertion

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 <[email protected]>

---
This fix is applicable to versions [2.6.29, 2.6.36]. The context for the second hunk needs to be reduced to 1 line for versions < 2.6.33 (git am -C1) as the logging call was changed.

Ben.

 drivers/net/bonding/bond_ipv6.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)
drivers/net/bonding/bond_ipv6.c +8 -1
index 121b073..78eb5fa 100644
@@ -70,6 +70,13 @@ 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;

@@ -88,7 +95,7 @@ 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;
Signature · 7 lines
1.7.2.3


-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
maintainer Acked-by on v1 1/1
#1 lore raw

From: Ben Hutchings <[email protected]>
Date: Mon, 07 Feb 2011 19:20:55 +0000

Quoted 11 lines

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 <[email protected]>
Acked-by David S. Miller <[email protected]>
#2 lore raw
Quoted 13 lines · David Miller

From: Ben Hutchings <[email protected]>
Date: Mon, 07 Feb 2011 19:20:55 +0000

Quoted 10 lines

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()).

Quoted 3 lines
Quoted 1 line
Signed-off-by Ben Hutchings <[email protected]>
Acked-by David S. Miller <[email protected]>

Great, thanks for the patch, now queued up for the next .32-stable release.

greg k-h