2 files changed, 14 insertions, 4 deletions

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index c532884f4fec..2dc7a1d97686 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -852,9 +852,18 @@ arp_notify - BOOLEAN
             or hardware address changes.
 
 arp_accept - BOOLEAN
-        Define behavior when gratuitous arp replies are received:
-        0 - drop gratuitous arp frames
-        1 - accept gratuitous arp frames
+        Define behavior for gratuitous ARP frames who's IP is not
+        already present in the ARP table:
+        0 - don't create new entries in the ARP table
+        1 - create new entries in the ARP table
+
+        Both replies and requests type gratuitous arp will trigger the
+        ARP table to be updated, if this setting is on.
+
+        If the ARP table already contains the IP address of the
+        gratuitous arp frame, the arp table will be updated regardless
+        if this setting is on or off.
+
 
 app_solicit - INTEGER
         The maximum number of probes to send to the user space ARP daemon
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 078709233bc4..1940b4df7699 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -907,7 +907,8 @@ static int arp_process(struct sk_buff *skb)
                    devices (strip is candidate)
                  */
                 if (n == NULL &&
-                    arp->ar_op == htons(ARPOP_REPLY) &&
+                    (arp->ar_op == htons(ARPOP_REPLY) ||
+                     (arp->ar_op == htons(ARPOP_REQUEST) && tip == sip)) &&
                     inet_addr_type(net, sip) == RTN_UNICAST)
                         n = __neigh_lookup(&arp_tbl, &sip, dev, 1);
         }