[ovs-dev] [PATCH v2 05/17] datapath: add processing of L3 packets
Yi Yang
yi.y.yang at intel.com
Wed Dec 28 12:26:18 UTC 2016
>From net-next commit 5108bbaddc37c1c8583f0cf2562d7d3463cd12cb.
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 at cisco.com>
Signed-off-by: Simon Horman <simon.horman at netronome.com>
Signed-off-by: Jiri Benc <jbenc at redhat.com>
Acked-by: Pravin B Shelar <pshelar at ovn.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Yi Yang <yi.y.yang at intel.com>
---
datapath/datapath.c | 14 +-----
datapath/flow.c | 120 +++++++++++++++++++++++++++++++++++++++++-----------
datapath/vport.c | 19 +++++++++
3 files changed, 115 insertions(+), 38 deletions(-)
diff --git a/datapath/datapath.c b/datapath/datapath.c
index ce2364a..1deb62d 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -571,7 +571,6 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
struct sw_flow *flow;
struct sw_flow_actions *sf_acts;
struct datapath *dp;
- struct ethhdr *eth;
struct vport *input_vport;
u16 mru = 0;
int len;
@@ -592,18 +591,6 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
nla_memcpy(__skb_put(packet, len), a[OVS_PACKET_ATTR_PACKET], len);
- skb_reset_mac_header(packet);
- eth = eth_hdr(packet);
-
- /* 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))
- packet->protocol = eth->h_proto;
- else
- packet->protocol = htons(ETH_P_802_2);
-
/* Set packet's mru */
if (a[OVS_PACKET_ATTR_MRU]) {
mru = nla_get_u16(a[OVS_PACKET_ATTR_MRU]);
@@ -630,6 +617,7 @@ 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/datapath/flow.c b/datapath/flow.c
index b66ad45..240bd00 100644
--- a/datapath/flow.c
+++ b/datapath/flow.c
@@ -301,6 +301,22 @@ static bool icmp6hdr_ok(struct sk_buff *skb)
sizeof(struct icmp6hdr));
}
+static void clear_vlan(struct sw_flow_key *key)
+{
+ key->eth.tci = 0;
+}
+
+static inline bool eth_type_is_vlan(__be16 ethertype)
+{
+ switch (ethertype) {
+ case htons(ETH_P_8021Q):
+ case htons(ETH_P_8021AD):
+ return true;
+ default:
+ return false;
+ }
+}
+
static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
{
struct qtag_prefix {
@@ -445,17 +461,20 @@ invalid:
*
* 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)
{
@@ -467,32 +486,40 @@ static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
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_is_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);
- key->eth.tci = 0;
- if (skb_vlan_tag_present(skb))
- key->eth.tci = htons(skb->vlan_tci);
- else if (eth->h_proto == htons(ETH_P_8021Q))
- if (unlikely(parse_vlan(skb, key)))
+ __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.tci = 0;
+ if (skb_vlan_tag_present(skb))
+ key->eth.tci = htons(skb->vlan_tci);
+ else if (eth->h_proto == htons(ETH_P_8021Q))
+ if (unlikely(parse_vlan(skb, key)))
+ return -ENOMEM;
+
+ key->eth.type = parse_ethertype(skb);
+ if (unlikely(key->eth.type == htons(0)))
return -ENOMEM;
- 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_network_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)) {
@@ -693,9 +720,25 @@ int ovs_flow_key_update(struct sk_buff *skb, struct sw_flow_key *key)
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);
@@ -721,7 +764,10 @@ int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,
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);
@@ -740,5 +786,29 @@ 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);
+ }
+
return key_extract(skb, key);
}
diff --git a/datapath/vport.c b/datapath/vport.c
index dbfec37..6511406 100644
--- a/datapath/vport.c
+++ b/datapath/vport.c
@@ -540,6 +540,25 @@ void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto)
{
int mtu = vport->dev->mtu;
+ switch (vport->dev->type) {
+ case ARPHRD_NONE:
+ if (mac_proto == MAC_PROTO_ETHERNET) {
+ skb_reset_network_header(skb);
+ skb_reset_mac_len(skb);
+ skb->protocol = htons(ETH_P_TEB);
+ } else if (mac_proto != MAC_PROTO_NONE) {
+ WARN_ON_ONCE(1);
+ goto drop;
+ }
+ break;
+ case ARPHRD_ETHER:
+ if (mac_proto != MAC_PROTO_ETHERNET)
+ goto drop;
+ break;
+ default:
+ goto drop;
+ }
+
if (unlikely(packet_length(skb, vport->dev) > mtu &&
!skb_is_gso(skb))) {
net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n",
--
2.1.0
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