Subject: Re: [PATCH net RESEND] bonding: set correct vlan id for alb xmit path

From: Ding Tianhong <[email-masked]>
Date: Wed, 12 Mar 2014 15:14:46 +0800

On 2014/3/12 0:26, Veaceslav Falico wrote:
> On Tue, Mar 11, 2014 at 10:14:00AM +0800, Ding Tianhong wrote:
>> The commit d3ab3ffd1d728d7ee77340e7e7e2c7cfe6a4013e
>> (bonding: use rlb_client_info->vlan_id instead of ->tag)
>> remove the rlb_client_info->tag, but occur some issues,
>> The vlan_get_tag() will return 0 for success and -EINVAL for
>> error, so the client_info->vlan_id always be set to 0 if the
>> vlan_get_tag return 0 for success, so the client_info would
>> never get a correct vlan id, and could not send a skb for vlan id 0.
> 
> VLAN id 0 is a reserved value, afaik, used for traffic prioritizing (by
> 8021p), so it shouldn't be treated as a normal VLAN.
> 
> Also, I remember that it was used internally for HW filtering, so it might
> interfere with those (if a devices has NETIF_F_HW_VLAN_CTAG_FITLER VLAN id
> 0 is added automatically).
> 
> Based on these I don't think that bonding should see VLAN 0 as a normal
> VLAN.
> 

Yes, the vlan id 0 is reserved, this tag could not indicate a valid vlan group although
I set some vlan dev to id 0 and they could work, this has trouble me for a long time,
maybe I need to add some restrict for vlan id, I will remove the vlan id 0 and resend, thanks.

Ding

>>
>> Fix this by convert the client_info->vlan_id from u16 to s16,
>> and set to -1 for default value, the s16 is enough for the range
>> of the vlan id.
>>
>> Fixes: d3ab3ffd1d7 (bonding: use rlb_client_info->vlan_id instead of ->tag)
>>
>> Cc: Jay Vosburgh <[email-masked]>
>> Cc: Veaceslav Falico <[email-masked]>
>> Cc: Andy Gospodarek <[email-masked]>
>> Signed-off-by: Ding Tianhong <[email-masked]>
>> ---
>> drivers/net/bonding/bond_alb.c | 8 ++++----
>> drivers/net/bonding/bond_alb.h | 2 +-
>> 2 files changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
>> index aaeeacf..fa95f70 100644
>> --- a/drivers/net/bonding/bond_alb.c
>> +++ b/drivers/net/bonding/bond_alb.c
>> @@ -539,7 +539,7 @@ static void rlb_update_client(struct rlb_client_info *client_info)
>>
>>         skb->dev = client_info->slave->dev;
>>
>> -        if (client_info->vlan_id) {
>> +        if (client_info->vlan_id >= 0) {
>>             skb = vlan_put_tag(skb, htons(ETH_P_8021Q), client_info->vlan_id);
>>             if (!skb) {
>>                 pr_err("%s: Error: failed to insert VLAN tag\n",
>> @@ -722,8 +722,8 @@ static struct slave *rlb_choose_channel(struct sk_buff *skb, struct bonding *bon
>>             client_info->ntt = 0;
>>         }
>>
>> -        if (!vlan_get_tag(skb, &client_info->vlan_id))
>> -            client_info->vlan_id = 0;
>> +        if (vlan_get_tag(skb, &client_info->vlan_id))
>> +            client_info->vlan_id = -1;
>>
>>         if (!client_info->assigned) {
>>             u32 prev_tbl_head = bond_info->rx_hashtbl_used_head;
>> @@ -827,7 +827,7 @@ static void rlb_init_table_entry_dst(struct rlb_client_info *entry)
>>     entry->used_prev = RLB_NULL_INDEX;
>>     entry->assigned = 0;
>>     entry->slave = NULL;
>> -    entry->vlan_id = 0;
>> +    entry->vlan_id = -1;
>> }
>> static void rlb_init_table_entry_src(struct rlb_client_info *entry)
>> {
>> diff --git a/drivers/net/bonding/bond_alb.h b/drivers/net/bonding/bond_alb.h
>> index e09dd4bf..b49af98 100644
>> --- a/drivers/net/bonding/bond_alb.h
>> +++ b/drivers/net/bonding/bond_alb.h
>> @@ -125,7 +125,7 @@ struct rlb_client_info {
>>     u8  assigned;        /* checking whether this entry is assigned */
>>     u8  ntt;        /* flag - need to transmit client info */
>>     struct slave *slave;    /* the slave assigned to this client */
>> -    unsigned short vlan_id;    /* VLAN tag associated with IP address */
>> +    short vlan_id;        /* VLAN tag associated with IP address */
>> };
>>
>> struct tlb_slave_info {
>> -- 
>> 1.8.0
>>
>>
> 
> .
>