[src/trunk]: src/sys/netinet6 avoid possible alignment issue. sync with kame

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

details:   https://anonhg.NetBSD.org/src/rev/beb57bce4d6b
branches:  trunk
changeset: 504537:beb57bce4d6b
user:      itojun <itojun%NetBSD.org@localhost>
date:      Sun Mar 04 16:49:17 2001 +0000

description:
avoid possible alignment issue.  sync with kame

diffstat:

 sys/netinet6/raw_ip6.c |  21 +++++++--------------
 1 files changed, 7 insertions(+), 14 deletions(-)

diffs (43 lines):

diff -r 5deb36017a77 -r beb57bce4d6b sys/netinet6/raw_ip6.c
--- a/sys/netinet6/raw_ip6.c    Sun Mar 04 16:24:39 2001 +0000
+++ b/sys/netinet6/raw_ip6.c    Sun Mar 04 16:49:17 2001 +0000
@@ -1,5 +1,5 @@
-/*     $NetBSD: raw_ip6.c,v 1.30 2001/02/26 07:20:45 itojun Exp $      */
-/*     $KAME: raw_ip6.c,v 1.66 2001/02/26 06:33:14 itojun Exp $        */
+/*     $NetBSD: raw_ip6.c,v 1.31 2001/03/04 16:49:17 itojun Exp $      */
+/*     $KAME: raw_ip6.c,v 1.69 2001/03/04 15:55:44 itojun Exp $        */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -469,9 +469,8 @@
 
        if (so->so_proto->pr_protocol == IPPROTO_ICMPV6 ||
            in6p->in6p_cksum != -1) {
-               struct mbuf *n;
                int off;
-               u_int16_t *p;
+               u_int16_t sum;
 
 #define        offsetof(type, member)  ((size_t)(&((type *)0)->member)) /* XXX */
 
@@ -486,16 +485,10 @@
                }
                off += sizeof(struct ip6_hdr);
 
-               n = m;
-               while (n && n->m_len <= off) {
-                       off -= n->m_len;
-                       n = n->m_next;
-               }
-               if (!n)
-                       goto bad;
-               p = (u_int16_t *)(mtod(n, caddr_t) + off);
-               *p = 0;
-               *p = in6_cksum(m, ip6->ip6_nxt, sizeof(*ip6), plen);
+               sum = 0;
+               m_copyback(m, off, sizeof(sum), (caddr_t)&sum);
+               sum = in6_cksum(m, ip6->ip6_nxt, sizeof(*ip6), plen);
+               m_copyback(m, off, sizeof(sum), (caddr_t)&sum);
        }
 
 #ifdef IPSEC