Subject: Re: [PATCH net] bonding: Don't assume 802.1Q when sending alb learning packets.

From: Vlad Yasevich <[email-masked]>
Date: Wed, 21 May 2014 16:10:14 -0400

On 05/21/2014 11:48 AM, Veaceslav Falico wrote:
> On Wed, May 21, 2014 at 11:24:39AM -0400, Vlad Yasevich wrote:
>> TLB/ALB learning packets always assume 802.1Q vlan protocol, but
>> that is no longer the case since we now have support for Q-in-Q
>> on top of bonding.  Pass the vlan protocol to alb_send_lp_vid()
>> so that the packets are properly tagged.
>>
>> CC: Jay Vosburgh <[email-masked]>
>> CC: Veaceslav Falico <[email-masked]>
> 
> There one more left - the rlb_update_client(), but it'll require a bit more
> hacking with rlb_client_info struct to work. Maybe some day in the future
> :).

Just looked at it and it looks like q-in-q support is very incompletely
in for alb mode bonding.

Some things I noticed:
  1) bond_start_xmit() looks at skb->protocol only which could be 8021Q
     or 8021ad.  Need to look for the protocol harder.
  2) all the arp recv_probe handlers need to know how skip past vlan
     headers to see if this is an ARP or not.
  3) rlb_client_info needs to know about all vlan headers, not just the
     outer one so that rlb_update_client() can function correctly.

-vlad

> 
> Acked-by: Veaceslav Falico <[email-masked]>
> 
>> CC: Andy Gospodarek <[email-masked]>
>> Signed-off-by: Vlad Yasevich <[email-masked]>
>> ---
>> drivers/net/bonding/bond_alb.c | 7 ++++---
>> 1 file changed, 4 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/net/bonding/bond_alb.c
>> b/drivers/net/bonding/bond_alb.c
>> index e538478..2ec945c 100644
>> --- a/drivers/net/bonding/bond_alb.c
>> +++ b/drivers/net/bonding/bond_alb.c
>> @@ -995,7 +995,7 @@ static void rlb_clear_vlan(struct bonding *bond,
>> unsigned short vlan_id)
>> /*********************** tlb/rlb shared functions *********************/
>>
>> static void alb_send_lp_vid(struct slave *slave, u8 mac_addr[],
>> -                u16 vid)
>> +                __be16 vlan_proto, u16 vid)
>> {
>>     struct learning_pkt pkt;
>>     struct sk_buff *skb;
>> @@ -1021,7 +1021,7 @@ static void alb_send_lp_vid(struct slave *slave,
>> u8 mac_addr[],
>>     skb->dev = slave->dev;
>>
>>     if (vid) {
>> -        skb = vlan_put_tag(skb, htons(ETH_P_8021Q), vid);
>> +        skb = vlan_put_tag(skb, vlan_proto, vid);
>>         if (!skb) {
>>             pr_err("%s: Error: failed to insert VLAN tag\n",
>>                    slave->bond->dev->name);
>> @@ -1040,13 +1040,14 @@ static void alb_send_learning_packets(struct
>> slave *slave, u8 mac_addr[])
>>     struct list_head *iter;
>>
>>     /* send untagged */
>> -    alb_send_lp_vid(slave, mac_addr, 0);
>> +    alb_send_lp_vid(slave, mac_addr, 0, 0);
>>
>>     /* loop through vlans and send one packet for each */
>>     rcu_read_lock();
>>     netdev_for_each_all_upper_dev_rcu(bond->dev, upper, iter) {
>>         if (is_vlan_dev(upper) && vlan_get_encap_level(upper) == 0)
>>             alb_send_lp_vid(slave, mac_addr,
>> +                    vlan_dev_vlan_proto(upper),
>>                     vlan_dev_vlan_id(upper));
>>     }
>>     rcu_read_unlock();
>> -- 
>> 1.9.0
>>