arp: Don't resolve own, configured IPv4 address

DHCP clients might try to resolve the assigned address to check if it's
already in use: don't resolve the configured IPv4 address.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/arp.c b/arp.c
index 17fad9f..89e4019 100644
--- a/arp.c
+++ b/arp.c
@@ -63,6 +63,10 @@ int arp(struct ctx *c, struct ethhdr *eh, size_t len)
 	if (*((uint32_t *)&am->sip) && !memcmp(am->sip, am->tip, 4))
 		return 1;
 
+	/* Don't resolve our own address, either. */
+	if (!memcmp(am->tip, &c->addr4, 4))
+		return 1;
+
 	ah->ar_op = htons(ARPOP_REPLY);
 	memcpy(am->tha, am->sha, ETH_ALEN);
 	memcpy(am->sha, c->mac, ETH_ALEN);