The sematics for setting a vlan tag are to modify the existing tag if one exists. This can be expressed as removing the existing tag first and then adding a new one. This simplifies the code by not requiring two copies of the logic that manipulates non-accelerated vlans and should not make a performance difference because the vlan tag is contained in a single cache line.
Signed-off-by: Jesse Gross <[email protected]> --- datapath/actions.c | 28 +++++++--------------------- 1 files changed, 7 insertions(+), 21 deletions(-) diff --git a/datapath/actions.c b/datapath/actions.c index 6c1ca49..e22756c 100644 --- a/datapath/actions.c +++ b/datapath/actions.c @@ -86,30 +86,16 @@ static struct sk_buff *strip_vlan(struct sk_buff *skb) static struct sk_buff *modify_vlan_tci(struct sk_buff *skb, __be16 tci) { - struct vlan_ethhdr *vh; - __be16 old_tci; - - if (vlan_tx_tag_present(skb) || skb->protocol != htons(ETH_P_8021Q)) - return __vlan_hwaccel_put_tag(skb, ntohs(tci)); - - skb = make_writable(skb, 0); - if (unlikely(!skb)) - return NULL; - - if (unlikely(skb->len < VLAN_ETH_HLEN)) - return skb; - - vh = vlan_eth_hdr(skb); - - old_tci = vh->h_vlan_TCI; - vh->h_vlan_TCI = tci; + if (!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_8021Q)) { + if (unlikely(skb->len < VLAN_ETH_HLEN)) + return skb; - if (get_ip_summed(skb) == OVS_CSUM_COMPLETE) { - __be16 diff[] = { ~old_tci, vh->h_vlan_TCI }; - skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum); + skb = strip_vlan(skb); + if (unlikely(!skb)) + return NULL; } - return skb; + return __vlan_hwaccel_put_tag(skb, ntohs(tci)); } static bool is_ip(struct sk_buff *skb) -- 1.7.4.1 _______________________________________________ dev mailing list [email protected] http://openvswitch.org/mailman/listinfo/dev
