+int
+dp_send_hello(struct datapath *dp, const struct sender *sender,
+ const struct ofp_header *request)
+{
+ if (request->version < OFP_VERSION) {
+ char err[64];
+ sprintf(err, "Only version 0x%02x supported", OFP_VERSION);
+ dp_send_error_msg(dp, sender, OFPET_HELLO_FAILED,
+ OFPHFC_INCOMPATIBLE, err, strlen(err));
+ return -EINVAL;
+ } else {
+ struct sk_buff *skb;
+ struct ofp_header *reply;
+
+ reply = alloc_openflow_skb(dp, sizeof *reply,
+ OFPT_HELLO, sender, &skb);
+ if (!reply)
+ return -ENOMEM;
+
+ return send_openflow_skb(skb, sender);
+ }
+}
+