1 files changed, 17 insertions, 7 deletions

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index ca6e1e6c1496..c22103cec823 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -641,12 +641,12 @@ void arp_xmit(struct sk_buff *skb)
 }
 EXPORT_SYMBOL(arp_xmit);
 
-static bool arp_is_garp(struct net_device *dev, int addr_type,
-                        __be16 ar_op,
+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 && addr_type == RTN_UNICAST;
+        bool is_garp = tip == sip;
 
         /* Gratuitous ARP _replies_ also require target hwaddr to be
          * the same as source.
@@ -659,6 +659,11 @@ static bool arp_is_garp(struct net_device *dev, int addr_type,
                         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;
 }
 
@@ -859,18 +864,23 @@ 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;
 
                 /* Unsolicited ARP is not accepted by default.
                    It is possible, that this option should be enabled for some
                    devices (strip is candidate)
                  */
-                is_garp = arp_is_garp(dev, addr_type, arp->ar_op,
+                is_garp = arp_is_garp(net, dev, &addr_type, arp->ar_op,
                                       sip, tip, sha, tha);
 
                 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);
         }