Add ability for the datapath to match IP address in ARPs

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

diff --git a/datapath/flow.c b/datapath/flow.c
index b24c242..ae60617 100644 (file)
--- a/datapath/flow.c
+++ b/datapath/flow.c
@@ -1,6 +1,9 @@
 /*
  * Distributed under the terms of the GNU GPL version 2.
  * Copyright (c) 2007, 2008, 2009 Nicira Networks.
+ *
+ * Significant portions of this file may be copied from parts of the Linux
+ * kernel, by Linus Torvalds and others.
  */
 
 #include "flow.h"
@@ -15,6 +18,7 @@
 #include <linux/module.h>
 #include <linux/in.h>
 #include <linux/rcupdate.h>
+#include <linux/if_arp.h>
 #include <linux/if_ether.h>
 #include <linux/ip.h>
 #include <linux/tcp.h>
@@ -26,6 +30,27 @@
 
 struct kmem_cache *flow_cache;
 
+struct arp_eth_header
+{
+       __be16      ar_hrd;     /* format of hardware address   */
+       __be16      ar_pro;     /* format of protocol address   */
+       unsigned char   ar_hln; /* length of hardware address   */
+       unsigned char   ar_pln; /* length of protocol address   */
+       __be16      ar_op;      /* ARP opcode (command)     */
+
+       /* Ethernet+IPv4 specific members. */
+       unsigned char       ar_sha[ETH_ALEN];   /* sender hardware address  */
+       unsigned char       ar_sip[4];          /* sender IP address        */
+       unsigned char       ar_tha[ETH_ALEN];   /* target hardware address  */
+       unsigned char       ar_tip[4];          /* target IP address        */
+} __attribute__((packed));
+
+static inline int arphdr_ok(struct sk_buff *skb)
+{
+       int nh_ofs = skb_network_offset(skb);
+       return pskb_may_pull(skb, nh_ofs + sizeof(struct arp_eth_header));
+}
+
 static inline int iphdr_ok(struct sk_buff *skb)
 {
        int nh_ofs = skb_network_offset(skb);
@@ -263,6 +288,27 @@ int flow_extract(struct sk_buff *skb, u16 in_port, struct odp_flow_key *key)
                } else {
                        retval = 1;
                }
+       } else if (key->dl_type == htons(ETH_P_ARP) && arphdr_ok(skb)) {
+               struct arp_eth_header *arp;
+
+               arp = (struct arp_eth_header *)skb_network_header(skb);
+
+        if (arp->ar_hrd == htons(1)
+                && arp->ar_pro == htons(ETH_P_IP)
+                && arp->ar_hln == ETH_ALEN
+                && arp->ar_pln == 4) {
+
+            /* We only match on the lower 8 bits of the opcode. */
+            if (ntohs(arp->ar_op) <= 0xff) {
+                key->nw_proto = ntohs(arp->ar_op);
+            }
+
+            if (key->nw_proto == ARPOP_REQUEST 
+                    || key->nw_proto == ARPOP_REPLY) {
+                memcpy(&key->nw_src, arp->ar_sip, sizeof(key->nw_src));
+                memcpy(&key->nw_dst, arp->ar_tip, sizeof(key->nw_dst));
+            }
+        }
        } else {
                skb_reset_transport_header(skb);
        }