From e0b8f73f17263e156988a45ebb6aa2e67fd70cc4 Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Mon, 30 Jun 2014 13:20:14 +0900 Subject: [PATCH] datapath: Allow pop and push MPLS actions after pop VLAN This patch loosens the restrictions surrounding push and pop MPLS actions such that they will be allowed after a pop VLAN action if the inner ethernet type is acceptable for pop and push MPLS actions. This implies that there is only one VLAN tag present. Some analysis of logic of this change is as follows: The purpose of tracking vlan_tci is to allow prohibition of push and pop MPLS actions in the presence of a VLAN. In this scenario the VLAN_TAG_PRESENT bit of vlan_tci is set and eth_type is that of the packet with the outermost VLAN tag removed. A pop VLAN action may clear vlan_tci as it removes the outermost VLAN tag and the push and pop MPLS logic may rely on eth_type for their prohibition logic. This will not allow push and pop MPLS on packets with multiple VLAN tags, regardless of if they are all remove using POP VLAN, as there is no mechanism to expose the inner ethernet type beyond that of the outermost VLAN tag. Suggested-by: Jesse Gross Signed-off-by: Simon Horman Signed-off-by: Jesse Gross --- datapath/flow_netlink.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/datapath/flow_netlink.c b/datapath/flow_netlink.c index 5ee315080..925e9fbd7 100644 --- a/datapath/flow_netlink.c +++ b/datapath/flow_netlink.c @@ -1666,6 +1666,7 @@ static int ovs_nla_copy_actions__(const struct nlattr *attr, } case OVS_ACTION_ATTR_POP_VLAN: + vlan_tci = htons(0); break; case OVS_ACTION_ATTR_PUSH_VLAN: @@ -1687,13 +1688,7 @@ static int ovs_nla_copy_actions__(const struct nlattr *attr, return -EINVAL; /* Prohibit push MPLS other than to a white list * for packets that have a known tag order. - * - * vlan_tci indicates that the packet at one - * point had a VLAN. It may have been subsequently - * removed using pop VLAN so this rule is stricter - * than necessary. This is because it is not - * possible to know if a VLAN is still present - * after a pop VLAN action. */ + */ if (vlan_tci & htons(VLAN_TAG_PRESENT) || (eth_type != htons(ETH_P_IP) && eth_type != htons(ETH_P_IPV6) &&