datapath: Fix compilation on newer old-style Xen kernels.

[sliver-openvswitch.git] / datapath / datapath.c

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 08b6200..539859a 100644 (file)
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -575,9 +575,10 @@ static int dp_frame_hook(struct net_bridge_port *p, struct sk_buff **pskb)
 #endif
 
 #if defined(CONFIG_XEN) && defined(HAVE_PROTO_DATA_VALID)
-/* This code is copied verbatim from net/dev/core.c in Xen's
- * linux-2.6.18-92.1.10.el5.xs5.0.0.394.644.  We can't call those functions
- * directly because they aren't exported. */
+/* This code is based on a skb_checksum_setup from net/dev/core.c from a
+ * combination of Lenny's 2.6.26 Xen kernel and Xen's
+ * linux-2.6.18-92.1.10.el5.xs5.0.0.394.644.  We can't call this function
+ * directly because it isn't exported in all versions. */
 static int skb_pull_up_to(struct sk_buff *skb, void *ptr)
 {
        if (ptr < (void *)skb->tail)
@@ -592,34 +593,57 @@ static int skb_pull_up_to(struct sk_buff *skb, void *ptr)
 
 int vswitch_skb_checksum_setup(struct sk_buff *skb)
 {
-       if (skb->proto_csum_blank) {
-               if (skb->protocol != htons(ETH_P_IP))
-                       goto out;
-               if (!skb_pull_up_to(skb, skb->nh.iph + 1))
-                       goto out;
-               skb->h.raw = (unsigned char *)skb->nh.iph + 4*skb->nh.iph->ihl;
-               switch (skb->nh.iph->protocol) {
-               case IPPROTO_TCP:
-                       skb->csum = offsetof(struct tcphdr, check);
-                       break;
-               case IPPROTO_UDP:
-                       skb->csum = offsetof(struct udphdr, check);
-                       break;
-               default:
-                       if (net_ratelimit())
-                               printk(KERN_ERR "Attempting to checksum a non-"
-                                      "TCP/UDP packet, dropping a protocol"
-                                      " %d packet", skb->nh.iph->protocol);
-                       goto out;
-               }
-               if (!skb_pull_up_to(skb, skb->h.raw + skb->csum + 2))
-                       goto out;
-               skb->ip_summed = CHECKSUM_HW;
-               skb->proto_csum_blank = 0;
+       struct iphdr *iph;
+       unsigned char *th;
+       int err = -EPROTO;
+       __u16 csum_start, csum_offset;
+
+       if (!skb->proto_csum_blank)
+               return 0;
+
+       if (skb->protocol != htons(ETH_P_IP))
+               goto out;
+
+       if (!skb_pull_up_to(skb, skb_network_header(skb) + 1))
+               goto out;
+
+       iph = ip_hdr(skb);
+       th = skb_network_header(skb) + 4 * iph->ihl;
+
+       csum_start = th - skb->head;
+       switch (iph->protocol) {
+       case IPPROTO_TCP:
+               csum_offset = offsetof(struct tcphdr, check);
+               break;
+       case IPPROTO_UDP:
+               csum_offset = offsetof(struct udphdr, check);
+               break;
+       default:
+               if (net_ratelimit())
+                       printk(KERN_ERR "Attempting to checksum a non-"
+                              "TCP/UDP packet, dropping a protocol"
+                              " %d packet", iph->protocol);
+               goto out;
        }
-       return 0;
+
+       if (!skb_pull_up_to(skb, th + csum_offset + 2))
+               goto out;
+
+       skb->ip_summed = CHECKSUM_PARTIAL;
+       skb->proto_csum_blank = 0;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
+       skb->csum_start = csum_start;
+       skb->csum_offset = csum_offset;
+#else
+       skb_set_transport_header(skb, csum_start - skb_headroom(skb));
+       skb->csum = csum_offset;
+#endif
+
+       err = 0;
+
 out:
-       return -EPROTO;
+       return err;
 }
 #else
 int vswitch_skb_checksum_setup(struct sk_buff *skb) { return 0; }