Merge branch 'ufs-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[karo-tx-linux.git] / net / ipv4 / arp.c

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index d54345a06f720fb1cd7632a364aa7e7e19ff6216..e9f3386a528b4a792839d5e50894a68d3097eb42 100644 (file)
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -641,6 +641,32 @@ void arp_xmit(struct sk_buff *skb)
 }
 EXPORT_SYMBOL(arp_xmit);
 
+static bool arp_is_garp(struct net *net, struct net_device *dev,
+                       int *addr_type, __be16 ar_op,
+                       __be32 sip, __be32 tip,
+                       unsigned char *sha, unsigned char *tha)
+{
+       bool is_garp = tip == sip;
+
+       /* Gratuitous ARP _replies_ also require target hwaddr to be
+        * the same as source.
+        */
+       if (is_garp && ar_op == htons(ARPOP_REPLY))
+               is_garp =
+                       /* IPv4 over IEEE 1394 doesn't provide target
+                        * hardware address field in its ARP payload.
+                        */
+                       tha &&
+                       !memcmp(tha, sha, dev->addr_len);
+
+       if (is_garp) {
+               *addr_type = inet_addr_type_dev_table(net, dev, sip);
+               if (*addr_type != RTN_UNICAST)
+                       is_garp = false;
+       }
+       return is_garp;
+}
+
 /*
  *     Process an arp request.
  */
@@ -837,29 +863,25 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb)
 
        n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
 
-       if (IN_DEV_ARP_ACCEPT(in_dev)) {
-               unsigned int addr_type = inet_addr_type_dev_table(net, dev, sip);
+       addr_type = -1;
+       if (n || IN_DEV_ARP_ACCEPT(in_dev)) {
+               is_garp = arp_is_garp(net, dev, &addr_type, arp->ar_op,
+                                     sip, tip, sha, tha);
+       }
 
+       if (IN_DEV_ARP_ACCEPT(in_dev)) {
                /* Unsolicited ARP is not accepted by default.
                   It is possible, that this option should be enabled for some
                   devices (strip is candidate)
                 */
-               is_garp = tip == sip && addr_type == RTN_UNICAST;
-
-               /* Unsolicited ARP _replies_ also require target hwaddr to be
-                * the same as source.
-                */
-               if (is_garp && arp->ar_op == htons(ARPOP_REPLY))
-                       is_garp =
-                               /* IPv4 over IEEE 1394 doesn't provide target
-                                * hardware address field in its ARP payload.
-                                */
-                               tha &&
-                               !memcmp(tha, sha, dev->addr_len);
-
                if (!n &&
-                   ((arp->ar_op == htons(ARPOP_REPLY)  &&
-                               addr_type == RTN_UNICAST) || is_garp))
+                   (is_garp ||
+                    (arp->ar_op == htons(ARPOP_REPLY) &&
+                     (addr_type == RTN_UNICAST ||
+                      (addr_type < 0 &&
+                       /* postpone calculation to as late as possible */
+                       inet_addr_type_dev_table(net, dev, sip) ==
+                               RTN_UNICAST)))))
                        n = __neigh_lookup(&arp_tbl, &sip, dev, 1);
        }