Do not always set skb->protocol to be the ethertype of the L3 header.
For a packet with non-accelerated VLAN tags skb->protocol needs to be
the ethertype of the outermost non-accelerated VLAN ethertype.
Any VLAN offloading is undone on the OVS netlink interface, and any
VLAN tags added by userspace are non-accelerated, as are double tagged
VLAN packets.
Fixes: 018c1dda5f ("openvswitch: 802.1AD Flow handling, actions, vlan parsing,
netlink attributes")
Fixes: 5108bbaddc ("openvswitch: add processing of L3 packets")
Signed-off-by: Jarno Rajahalme <ja...@ovn.org>
---
v3: Set skb->protocol properly also for double tagged packets, as suggested
by Pravin. This patch is no longer needed for the MTU test failure, as
the new patch 2/3 addresses that.
net/openvswitch/datapath.c | 1 -
net/openvswitch/flow.c | 62 +++++++++++++++++++++++-----------------------
2 files changed, 31 insertions(+), 32 deletions(-)
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 2d4c4d3..9c62b63 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -606,7 +606,6 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb,
struct genl_info *info)
rcu_assign_pointer(flow->sf_acts, acts);
packet->priority = flow->key.phy.priority;
packet->mark = flow->key.phy.skb_mark;
- packet->protocol = flow->key.eth.type;
rcu_read_lock();
dp = get_dp_rcu(net, ovs_header->dp_ifindex);
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index 08aa926..e2fe2e5 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -354,6 +354,7 @@ static int parse_vlan(struct sk_buff *skb, struct
sw_flow_key *key)
res = parse_vlan_tag(skb, &key->eth.vlan);
if (res <= 0)
return res;
+ skb->protocol = key->eth.vlan.tpid;
}
/* Parse inner vlan tag. */
@@ -361,6 +362,11 @@ static int parse_vlan(struct sk_buff *skb, struct
sw_flow_key *key)
if (res <= 0)
return res;
+ /* If the outer vlan tag was accelerated, skb->protocol should
+ * refelect the inner vlan type. */
+ if (!eth_type_vlan(skb->protocol))
+ skb->protocol = key->eth.cvlan.tpid;
+
return 0;
}
@@ -477,12 +483,18 @@ static int parse_icmpv6(struct sk_buff *skb, struct
sw_flow_key *key,
}
/**
- * key_extract - extracts a flow key from an Ethernet frame.
+ * key_extract - extracts a flow key from a packet with or without an
+ * Ethernet header.
* @skb: sk_buff that contains the frame, with skb->data pointing to the
- * Ethernet header
+ * beginning of the packet.
* @key: output flow key
*
- * The caller must ensure that skb->len >= ETH_HLEN.
+ * 'key->mac_proto' must be initialized to indicate the frame type. For an L3
+ * frame 'key->mac_proto' must equal 'MAC_PROTO_NONE', and the caller must
+ * ensure that 'skb->protocol' is set to the ethertype of the L3 header.
+ * Otherwise the presence of an Ethernet header is assumed and the caller must
+ * ensure that skb->len >= ETH_HLEN and that 'skb->protocol' is initialized to
+ * zero.
*
* Returns 0 if successful, otherwise a negative errno value.
*
@@ -498,8 +510,9 @@ static int parse_icmpv6(struct sk_buff *skb, struct
sw_flow_key *key,
* of a correct length, otherwise the same as skb->network_header.
* For other key->eth.type values it is left untouched.
*
- * - skb->protocol: the type of the data starting at skb->network_header.
- * Equals to key->eth.type.
+ * - skb->protocol: For non-accelerated VLAN, one of the VLAN ether types,
+ * otherwise the same as key->eth.type, the ether type of the payload
+ * starting at skb->network_header.
*/
static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
{
@@ -531,15 +544,16 @@ static int key_extract(struct sk_buff *skb, struct
sw_flow_key *key)
if (unlikely(parse_vlan(skb, key)))
return -ENOMEM;
- skb->protocol = parse_ethertype(skb);
- if (unlikely(skb->protocol == htons(0)))
+ key->eth.type = parse_ethertype(skb);
+ if (unlikely(key->eth.type == htons(0)))
return -ENOMEM;
skb_reset_network_header(skb);
__skb_push(skb, skb->data - skb_mac_header(skb));
}
skb_reset_mac_len(skb);
- key->eth.type = skb->protocol;
+ if (!eth_type_vlan(skb->protocol))
+ skb->protocol = key->eth.type;
/* Network layer. */
if (key->eth.type == htons(ETH_P_IP)) {
@@ -800,29 +814,15 @@ int ovs_flow_key_extract_userspace(struct net *net, const
struct nlattr *attr,
if (err)
return err;
- if (ovs_key_mac_proto(key) == MAC_PROTO_NONE) {
- /* key_extract assumes that skb->protocol is set-up for
- * layer 3 packets which is the case for other callers,
- * in particular packets recieved from the network stack.
- * Here the correct value can be set from the metadata
- * extracted above.
- */
- skb->protocol = key->eth.type;
- } else {
- struct ethhdr *eth;
-
- skb_reset_mac_header(skb);
- eth = eth_hdr(skb);
-
- /* Normally, setting the skb 'protocol' field would be
- * handled by a call to eth_type_trans(), but it assumes
- * there's a sending device, which we may not have.
- */
- if (eth_proto_is_802_3(eth->h_proto))
- skb->protocol = eth->h_proto;
- else
- skb->protocol = htons(ETH_P_802_2);
- }
+ /* key_extract assumes that skb->protocol is set-up for
+ * layer 3 packets which is the case for other callers,
+ * in particular packets recieved from the network stack.
+ * Here the correct value can be set from the metadata
+ * extracted above. For layer 2 packets we initialize
+ * skb->protocol to zero and set it in key_extract() while
+ * parsing the L2 headers.
+ */
+ skb->protocol = key->eth.type;
return key_extract(skb, key);
}
--
2.1.4
