On 2019/01/17 17:17, Zahari Doychev wrote: > On Tue, Jan 15, 2019 at 03:11:28PM +0900, Toshiaki Makita wrote: >> On 2019/01/13 22:59, Zahari Doychev wrote: >>> Use the skb->mac_len instead of using the ETH_HLEN when pushing the skb >>> data pointer. This fixes sending incorrect packets when more than one >>> vlan tags are pushed by tc-vlan and the mac header length is bigger than >>> ETH_HLEN. In this way the vlan tagged contained in the skb is inserted at >>> right offset in the packet payload before sending the packet. >>> >>> Signed-off-by: Zahari Doychev <zahari.doychev@xxxxxxxxx> >>> --- >>> net/bridge/br_forward.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c >>> index 5372e2042adf..55f928043f77 100644 >>> --- a/net/bridge/br_forward.c >>> +++ b/net/bridge/br_forward.c >>> @@ -39,7 +39,7 @@ int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb >>> if (!is_skb_forwardable(skb->dev, skb)) >>> goto drop; >>> >>> - skb_push(skb, ETH_HLEN); >>> + skb_push(skb, skb->mac_len); >>> br_drop_fake_rtable(skb); >>> >>> if (skb->ip_summed == CHECKSUM_PARTIAL && >>> >> >> I guess you mean skb->data points to mac_header + ETH_HLEN + VLAN_HLEN >> when bridge receives skbs in br_handle_frame()? > > yes, this is what I see. > >> If so, the behavior of act_vlan is odd. Normal double tagged skbs from >> hardware devices should have skb->data pointing to mac_header + ETH_HLEN >> because they just call eth_type_trans() before entering >> netif_receive_skb()... >> I think act_vlan needs some fix. > > The act_valn is using the skb_vlan_push(...) to add the vlan tags and in this > way increasing the skb->data and mac_len. So I think I can add a fix there to > set the skb->data to point to mac_header + ETH_HLEN when more tags are added. As skb->data always points to mac_header after calling skb_vlan_push(), we probably need to remember mac_len before invocation of it? The problem should be this part in tcf_vlan_act(): > out: > if (skb_at_tc_ingress(skb)) > skb_pull_rcsum(skb, skb->mac_len); skb->mac_len should not be used here. -- Toshiaki Makita
