openvswitch: add processing of L3 packets
Support receiving, extracting flow key and sending of L3 packets (packets
without an Ethernet header).
Note that even after this patch, non-Ethernet interfaces are still not
allowed to be added to bridges. Similarly, netlink interface for sending and
receiving L3 packets to/from user space is not in place yet.
Based on previous versions by Lorand Jakab and Simon Horman.
Signed-off-by: Lorand Jakab <lojakab@cisco.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index 96c8c47..08aa926 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -334,14 +334,17 @@
return 1;
}
-static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
+static void clear_vlan(struct sw_flow_key *key)
{
- int res;
-
key->eth.vlan.tci = 0;
key->eth.vlan.tpid = 0;
key->eth.cvlan.tci = 0;
key->eth.cvlan.tpid = 0;
+}
+
+static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
+{
+ int res;
if (skb_vlan_tag_present(skb)) {
key->eth.vlan.tci = htons(skb->vlan_tci);
@@ -483,17 +486,20 @@
*
* Returns 0 if successful, otherwise a negative errno value.
*
- * Initializes @skb header pointers as follows:
+ * Initializes @skb header fields as follows:
*
- * - skb->mac_header: the Ethernet header.
+ * - skb->mac_header: the L2 header.
*
- * - skb->network_header: just past the Ethernet header, or just past the
- * VLAN header, to the first byte of the Ethernet payload.
+ * - skb->network_header: just past the L2 header, or just past the
+ * VLAN header, to the first byte of the L2 payload.
*
* - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
* on output, then just past the IP header, if one is present and
* 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.
*/
static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
{
@@ -505,28 +511,35 @@
skb_reset_mac_header(skb);
- /* Link layer. We are guaranteed to have at least the 14 byte Ethernet
- * header in the linear data area.
- */
- eth = eth_hdr(skb);
- ether_addr_copy(key->eth.src, eth->h_source);
- ether_addr_copy(key->eth.dst, eth->h_dest);
+ /* Link layer. */
+ clear_vlan(key);
+ if (key->mac_proto == MAC_PROTO_NONE) {
+ if (unlikely(eth_type_vlan(skb->protocol)))
+ return -EINVAL;
- __skb_pull(skb, 2 * ETH_ALEN);
- /* We are going to push all headers that we pull, so no need to
- * update skb->csum here.
- */
+ skb_reset_network_header(skb);
+ } else {
+ eth = eth_hdr(skb);
+ ether_addr_copy(key->eth.src, eth->h_source);
+ ether_addr_copy(key->eth.dst, eth->h_dest);
- if (unlikely(parse_vlan(skb, key)))
- return -ENOMEM;
+ __skb_pull(skb, 2 * ETH_ALEN);
+ /* We are going to push all headers that we pull, so no need to
+ * update skb->csum here.
+ */
- key->eth.type = parse_ethertype(skb);
- if (unlikely(key->eth.type == htons(0)))
- return -ENOMEM;
+ if (unlikely(parse_vlan(skb, key)))
+ return -ENOMEM;
- skb_reset_network_header(skb);
+ skb->protocol = parse_ethertype(skb);
+ if (unlikely(skb->protocol == htons(0)))
+ return -ENOMEM;
+
+ skb_reset_network_header(skb);
+ __skb_push(skb, skb->data - skb_mac_header(skb));
+ }
skb_reset_mac_len(skb);
- __skb_push(skb, skb->data - skb_mac_header(skb));
+ key->eth.type = skb->protocol;
/* Network layer. */
if (key->eth.type == htons(ETH_P_IP)) {
@@ -721,9 +734,25 @@
return key_extract(skb, key);
}
+static int key_extract_mac_proto(struct sk_buff *skb)
+{
+ switch (skb->dev->type) {
+ case ARPHRD_ETHER:
+ return MAC_PROTO_ETHERNET;
+ case ARPHRD_NONE:
+ if (skb->protocol == htons(ETH_P_TEB))
+ return MAC_PROTO_ETHERNET;
+ return MAC_PROTO_NONE;
+ }
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+}
+
int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,
struct sk_buff *skb, struct sw_flow_key *key)
{
+ int res;
+
/* Extract metadata from packet. */
if (tun_info) {
key->tun_proto = ip_tunnel_info_af(tun_info);
@@ -751,7 +780,10 @@
key->phy.skb_mark = skb->mark;
ovs_ct_fill_key(skb, key);
key->ovs_flow_hash = 0;
- key->mac_proto = MAC_PROTO_ETHERNET;
+ res = key_extract_mac_proto(skb);
+ if (res < 0)
+ return res;
+ key->mac_proto = res;
key->recirc_id = 0;
return key_extract(skb, key);
@@ -768,5 +800,29 @@
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);
+ }
+
return key_extract(skb, key);
}