X-Git-Url: https://git.kernelconcepts.de/?a=blobdiff_plain;f=net%2Flink_local.c;h=4152fae5bacba34c051bf2f877a11d435630325e;hb=42817eb85de1d7dec399c75dbd133ea6b5351a72;hp=1ba796ebdf949999f8663ff30049c1c085d43f56;hpb=095728803eedfce850a2f85828f79500cb09979e;p=karo-tx-uboot.git

diff --git a/net/link_local.c b/net/link_local.c
index 1ba796ebdf..4152fae5ba 100644
--- a/net/link_local.c
+++ b/net/link_local.c
@@ -206,6 +206,7 @@ void link_local_receive_arp(struct arp_hdr *arp, int len)
 {
 	int source_ip_conflict;
 	int target_ip_conflict;
+	IPaddr_t null_ip = 0;
 
 	if (state == DISABLED)
 		return;
@@ -267,10 +268,18 @@ void link_local_receive_arp(struct arp_hdr *arp, int len)
 	) {
 		source_ip_conflict = 1;
 	}
-	if (arp->ar_op == htons(ARPOP_REQUEST)
-	 && memcmp(&arp->ar_tpa, &ip, ARP_PLEN) == 0
-	 && memcmp(&arp->ar_tha, NetOurEther, ARP_HLEN) != 0
-	) {
+
+	/*
+	 * According to RFC 3927, section 2.2.1:
+	 * Check if packet is an ARP probe by checking for a null source IP
+	 * then check that target IP is equal to ours and source hw addr
+	 * is not equal to ours. This condition should cause a conflict only
+	 * during probe.
+	 */
+	if (arp->ar_op == htons(ARPOP_REQUEST) &&
+	    memcmp(&arp->ar_spa, &null_ip, ARP_PLEN) == 0 &&
+	    memcmp(&arp->ar_tpa, &ip, ARP_PLEN) == 0 &&
+	    memcmp(&arp->ar_sha, NetOurEther, ARP_HLEN) != 0) {
 		target_ip_conflict = 1;
 	}