Re: [PATCH v2.39 7/7] datapath: Add basic MPLS support to kernel
From: Pravin Shelar <hidden>
Date: 2013-09-17 18:38:19
On Mon, Sep 9, 2013 at 12:20 AM, Simon Horman [off-list ref] wrote:
Allow datapath to recognize and extract MPLS labels into flow keys and execute actions which push, pop, and set labels on packets. Based heavily on work by Leo Alterman, Ravi K, Isaku Yamahata and Joe Stringer. Cc: Ravi K <redacted> Cc: Leo Alterman <redacted> Cc: Isaku Yamahata <redacted> Cc: Joe Stringer <redacted> Signed-off-by: Simon Horman <horms@verge.net.au> ---
....
quoted hunk ↗ jump to hunk
diff --git a/datapath/datapath.h b/datapath/datapath.h index 5d50dd4..babae3b 100644 --- a/datapath/datapath.h +++ b/datapath/datapath.h@@ -36,6 +36,10 @@ #define SAMPLE_ACTION_DEPTH 3 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,11,0) +#define HAVE_INNER_PROTOCOL +#endif + /** * struct dp_stats_percpu - per-cpu packet processing statistics for a given * datapath.@@ -93,11 +97,16 @@ struct datapath { * @pkt_key: The flow information extracted from the packet. Must be nonnull. * @tun_key: Key for the tunnel that encapsulated this packet. NULL if the * packet is not being tunneled. + * @inner_protocol: Provides a substitute for the skb->inner_protocol field on + * kernels before 3.11. */ struct ovs_skb_cb { struct sw_flow *flow; struct sw_flow_key *pkt_key; struct ovs_key_ipv4_tunnel *tun_key; +#ifndef HAVE_INNER_PROTOCOL + __be16 inner_protocol; +#endif }; #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
Can you move this to compat struct ovs_gso_cb {}
....
+struct sk_buff *rpl___skb_gso_segment(struct sk_buff *skb,
+ netdev_features_t features,
+ bool tx_path)
+{
+ struct sk_buff *skb_gso;
+ __be16 type = skb->protocol;
+
+ skb->protocol = skb_network_protocol(skb);
+
+ /* this hack needed to get regular skb_gso_segment() */
+#ifdef HAVE___SKB_GSO_SEGMENT
+#undef __skb_gso_segment
+ skb_gso = __skb_gso_segment(skb, features, tx_path);
+#else
+#undef skb_gso_segment
+ skb_gso = skb_gso_segment(skb, features);
+#endif
+
+ if (!skb_gso || IS_ERR(skb_gso))
+ return skb_gso;
+
+ skb = skb_gso;
+ while (skb) {
+ skb->protocol = type;
+ skb = skb->next;
+ }
+Protocol set is required if there is MPLS header, which is rare case. So I think we can skip this loop if there is no mpls.
+ return skb_gso; +} + +struct sk_buff *rpl_skb_gso_segment(struct sk_buff *skb,
.....
quoted hunk ↗ jump to hunk
+ + if (vlan_tx_tag_present(skb) && !dev_supports_vlan_tx(skb->dev)) + vlan = true; + + if (vlan || mpls) { + netdev_features_t features; features = netif_skb_features(skb);@@ -296,6 +309,20 @@ static int netdev_send(struct vport *vport, struct sk_buff *skb) features &= ~(NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_UFO | NETIF_F_FSO); + /* As of v3.11 the kernel provides an mpls_features field in + * struct net_device which allows devices to advertise which + * features its supports for MPLS. This value defaults to + * NETIF_F_SG and as of v3.11. + * + * This compatibility code is intended for kernels older + * than v3.11 that do not support MPLS GSO and thus do not + * provide mpls_features. Thus this code uses NETIF_F_SG + * directly in place of mpls_features. + */ + + if (mpls) + features &= NETIF_F_SG; + if (netif_needs_gso(skb, features)) { struct sk_buff *nskb;@@ -319,10 +346,12 @@ static int netdev_send(struct vport *vport, struct sk_buff *skb) nskb = skb->next; skb->next = NULL; - skb = __vlan_put_tag(skb, skb->vlan_proto, vlan_tx_tag_get(skb)); + if (vlan) + skb = __vlan_put_tag(skb, skb->vlan_proto, vlan_tx_tag_get(skb)); if (likely(skb)) { len += skb->len; - vlan_set_tci(skb, 0); + if (vlan) + vlan_set_tci(skb, 0); dev_queue_xmit(skb); }@@ -333,10 +362,12 @@ static int netdev_send(struct vport *vport, struct sk_buff *skb) } tag: - skb = __vlan_put_tag(skb, skb->vlan_proto, vlan_tx_tag_get(skb)); - if (unlikely(!skb)) - return 0; - vlan_set_tci(skb, 0); + if (vlan) { + skb = __vlan_put_tag(skb, skb->vlan_proto, vlan_tx_tag_get(skb)); + if (unlikely(!skb)) + return 0; + vlan_set_tci(skb, 0); + } }
I think we can simplify code by pushing vlan and then segmenting skb, the way we do it for MPLS.