[src/trunk]: src/sys/netinet One more time: backout arp header alignment, now...

[martin <martin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/77ea07f28d57
branches:  trunk
changeset: 952742:77ea07f28d57
user:      martin <martin%NetBSD.org@localhost>
date:      Tue Feb 16 10:22:52 2021 +0000

description:
One more time: backout arp header alignment, now that the alignment
asserted has been aligned to reality.
Also remove unused ARP_HDR_ALIGNED_P macro. Pointed out by roy.

diffstat:

 sys/netinet/if_arp.c |  17 ++++++-----------
 1 files changed, 6 insertions(+), 11 deletions(-)

diffs (45 lines):

diff -r 39cea81b2aea -r 77ea07f28d57 sys/netinet/if_arp.c
--- a/sys/netinet/if_arp.c      Tue Feb 16 10:20:56 2021 +0000
+++ b/sys/netinet/if_arp.c      Tue Feb 16 10:22:52 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_arp.c,v 1.305 2021/02/16 05:44:13 martin Exp $      */
+/*     $NetBSD: if_arp.c,v 1.306 2021/02/16 10:22:52 martin 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 1.305 2021/02/16 05:44:13 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.306 2021/02/16 10:22:52 martin Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -133,12 +133,6 @@
  */
 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL
 
-#ifdef __NO_STRICT_ALIGNMENT
-#define        ARP_HDR_ALIGNED_P(ar)   1
-#else
-#define        ARP_HDR_ALIGNED_P(ar)   ((((vaddr_t) (ar)) & 1) == 0)
-#endif
-
 /* timers */
 static int arp_reachable = REACHABLE_TIME;
 static int arp_retrans = RETRANS_TIMER;
@@ -707,9 +701,10 @@
                MCLAIM(m, &arpdomain.dom_mowner);
                ARP_STATINC(ARP_STAT_RCVTOTAL);
 
-               if (m_get_aligned_hdr(&m, ARP_HDR_ALIGNMENT, sizeof(*ar),
-                   false) != 0)
-                       goto badlen;
+               if (__predict_false(m->m_len < sizeof(*ar))) {
+                       if ((m = m_pullup(m, sizeof(*ar))) == NULL)
+                               goto badlen;
+               }
                ar = mtod(m, struct arphdr *);
                KASSERT(POINTER_ALIGNED_P(ar, ARP_HDR_ALIGNMENT));