datapath: Fix pop_vlan().

Following patch fixes bug in pop_vlan code by updating ethernet
header len.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>

diff --git a/datapath/actions.c b/datapath/actions.c
index b430090..70fe153 100644 (file)
--- a/datapath/actions.c
+++ b/datapath/actions.c
@@ -50,8 +50,7 @@ static int make_writable(struct sk_buff *skb, int write_len)
 /* remove VLAN header from packet and update csum accrodingly. */
 static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
 {
-       struct ethhdr *eh;
-       struct vlan_ethhdr *veth;
+       struct vlan_hdr *vhdr;
        int err;
 
        err = make_writable(skb, VLAN_ETH_HLEN);
@@ -62,15 +61,15 @@ static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
                skb->csum = csum_sub(skb->csum, csum_partial(skb->data
                                        + ETH_HLEN, VLAN_HLEN, 0));
 
-       veth = (struct vlan_ethhdr *) skb->data;
-       *current_tci = veth->h_vlan_TCI;
+       vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
+       *current_tci = vhdr->h_vlan_TCI;
 
        memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
+       __skb_pull(skb, VLAN_HLEN);
 
-       eh = (struct ethhdr *)__skb_pull(skb, VLAN_HLEN);
-
-       skb->protocol = eh->h_proto;
+       vlan_set_encap_proto(skb, vhdr);
        skb->mac_header += VLAN_HLEN;
+       skb_reset_mac_len(skb);
 
        return 0;
 }

diff --git a/datapath/linux/compat/include/linux/if_vlan.h b/datapath/linux/compat/include/linux/if_vlan.h
index f418407..326abb2 100644 (file)
--- a/datapath/linux/compat/include/linux/if_vlan.h
+++ b/datapath/linux/compat/include/linux/if_vlan.h
@@ -54,4 +54,38 @@ static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 #define VLAN_TAG_PRESENT       VLAN_CFI_MASK
 #endif
 
+/* This function is not exported from kernel. OVS Upstreaming patch will
+ * fix that. */
+static inline void vlan_set_encap_proto(struct sk_buff *skb, struct vlan_hdr *vhdr)
+{
+       __be16 proto;
+       unsigned char *rawp;
+
+       /*
+        * Was a VLAN packet, grab the encapsulated protocol, which the layer
+        * three protocols care about.
+        */
+
+       proto = vhdr->h_vlan_encapsulated_proto;
+       if (ntohs(proto) >= 1536) {
+               skb->protocol = proto;
+               return;
+       }
+
+       rawp = skb->data;
+       if (*(unsigned short *) rawp == 0xFFFF)
+               /*
+                * This is a magic hack to spot IPX packets. Older Novell
+                * breaks the protocol design and runs IPX over 802.3 without
+                * an 802.2 LLC layer. We look for FFFF which isn't a used
+                * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
+                * but does for the rest.
+                */
+               skb->protocol = htons(ETH_P_802_3);
+       else
+               /*
+                * Real 802.2 LLC
+                */
+               skb->protocol = htons(ETH_P_802_2);
+}
 #endif /* linux/if_vlan.h wrapper */

diff --git a/datapath/linux/compat/include/linux/skbuff.h b/datapath/linux/compat/include/linux/skbuff.h
index 456d744..311bfdb 100644 (file)
--- a/datapath/linux/compat/include/linux/skbuff.h
+++ b/datapath/linux/compat/include/linux/skbuff.h
@@ -239,4 +239,10 @@ static inline struct page *skb_frag_page(const skb_frag_t *frag)
 }
 #endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,0,0)
+static inline void skb_reset_mac_len(struct sk_buff *skb)
+{
+       skb->mac_len = skb->network_header - skb->mac_header;
+}
+#endif
 #endif