From a6e18ff111701b4ff6947605bfbe9594ec42a6e8 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Mon, 16 Nov 2015 15:43:44 -0500 Subject: [PATCH 1/2] vlan: Fix untag operations of stacked vlans with REORDER_HEADER off When we have multiple stacked vlan devices all of which have turned off REORDER_HEADER flag, the untag operation does not locate the ethernet addresses correctly for nested vlans. The reason is that in case of REORDER_HEADER flag being off, the outer vlan headers are put back and the mac_len is adjusted to account for the presense of the header. Then, the subsequent untag operation, for the next level vlan, always use VLAN_ETH_HLEN to locate the begining of the ethernet header and that ends up being a multiple of 4 bytes short of the actuall beginning of the mac header (the multiple depending on the how many vlan encapsulations ethere are). As a reslult, if there are multiple levles of vlan devices with REODER_HEADER being off, the recevied packets end up being dropped. To solve this, we use skb->mac_len as the offset. The value is always set on receive path and starts out as a ETH_HLEN. The value is also updated when the vlan header manupations occur so we know it will be correct. Signed-off-by: Vladislav Yasevich Signed-off-by: David S. Miller --- net/core/skbuff.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index aa41e6dd6429..152b9c70e252 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4268,7 +4268,8 @@ static struct sk_buff *skb_reorder_vlan_header(struct sk_buff *skb) return NULL; } - memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN); + memmove(skb->data - ETH_HLEN, skb->data - skb->mac_len, + 2 * ETH_ALEN); skb->mac_header += VLAN_HLEN; return skb; } From 28f9ee22bcdd84726dbf6267d0b58f254166b900 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Mon, 16 Nov 2015 15:43:45 -0500 Subject: [PATCH 2/2] vlan: Do not put vlan headers back on bridge and macvlan ports When a vlan is configured with REORDER_HEADER set to 0, the vlan header is put back into the packet and makes it appear that the vlan header is still there even after it's been processed. This posses a problem for bridge and macvlan ports. The packets passed to those device may be forwarded and at the time of the forward, vlan headers end up being unexpectedly present. With the patch, we make sure that we do not put the vlan header back (when REORDER_HEADER is 0) if a bridge or macvlan has been configured on top of the vlan device. Signed-off-by: Vladislav Yasevich Signed-off-by: David S. Miller --- include/linux/netdevice.h | 5 +++++ net/8021q/vlan_core.c | 4 +++- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index cc221b967687..67bfac1abfc1 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3857,6 +3857,11 @@ static inline bool netif_is_bridge_master(const struct net_device *dev) return dev->priv_flags & IFF_EBRIDGE; } +static inline bool netif_is_bridge_port(const struct net_device *dev) +{ + return dev->priv_flags & IFF_BRIDGE_PORT; +} + static inline bool netif_is_ovs_master(const struct net_device *dev) { return dev->priv_flags & IFF_OPENVSWITCH; diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c index 496b27588493..e2ed69850489 100644 --- a/net/8021q/vlan_core.c +++ b/net/8021q/vlan_core.c @@ -30,7 +30,9 @@ bool vlan_do_receive(struct sk_buff **skbp) skb->pkt_type = PACKET_HOST; } - if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR)) { + if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR) && + !netif_is_macvlan_port(vlan_dev) && + !netif_is_bridge_port(vlan_dev)) { unsigned int offset = skb->data - skb_mac_header(skb); /*