Module Name: src
Committed By: ozaki-r
Date: Mon Sep 9 07:25:32 UTC 2024
Modified Files:
src/sys/netinet: if_arp.c
Log Message:
arp: allow to send packets without an ARP resolution just after receiving an
ARP request
On receiving an ARP request, the current implemention creates an ARP
cache entry but with ND_LLINFO_NOSTATE. Such an entry still needs
an ARP resolution to send back a packet to the requester. The original
behavior before introducing the common ND framework didn't need the
resolution. IPv6 doesn't as well. To restore the original behavior,
make a new ARP cache entry with ND_LLINFO_STALE like IPv6 does.
To generate a diff of this commit:
cvs rdiff -u -r1.314 -r1.315 src/sys/netinet/if_arp.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/netinet/if_arp.c
diff -u src/sys/netinet/if_arp.c:1.314 src/sys/netinet/if_arp.c:1.315
--- src/sys/netinet/if_arp.c:1.314 Tue Aug 20 08:21:04 2024
+++ src/sys/netinet/if_arp.c Mon Sep 9 07:25:32 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: if_arp.c,v 1.314 2024/08/20 08:21:04 ozaki-r Exp $ */
+/* $NetBSD: if_arp.c,v 1.315 2024/09/09 07:25:32 ozaki-r Exp $ */
/*
* Copyright (c) 1998, 2000, 2008 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.314 2024/08/20 08:21:04 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.315 2024/09/09 07:25:32 ozaki-r Exp $");
#ifdef _KERNEL_OPT
#include "opt_ddb.h"
@@ -1034,6 +1034,17 @@ again:
/* This was a solicited ARP reply. */
la->ln_byhint = 0;
new_state = ND_LLINFO_REACHABLE;
+ } else if (op == ARPOP_REQUEST &&
+ (la->ln_state == ND_LLINFO_NOSTATE ||
+ la->ln_state == ND_LLINFO_INCOMPLETE)) {
+ /*
+ * If an ARP request comes but there is no entry
+ * and a new one has been created or an entry exists
+ * but incomplete, make it stale to allow to send
+ * packets to the requester without an ARP resolution.
+ */
+ la->ln_byhint = 0;
+ new_state = ND_LLINFO_STALE;
}
rt_cmd = la->la_flags & LLE_VALID ? 0 : RTM_ADD;
}
