[src/trunk]: src/usr.sbin/tcpdump IPv6 UDP header checksum.

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

details:   https://anonhg.NetBSD.org/src/rev/6c46e320a5e8
branches:  trunk
changeset: 495610:6c46e320a5e8
user:      itojun <itojun%NetBSD.org@localhost>
date:      Tue Aug 01 17:35:18 2000 +0000

description:
IPv6 UDP header checksum.

diffstat:

 usr.sbin/tcpdump/print-udp.c |  66 ++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 63 insertions(+), 3 deletions(-)

diffs (101 lines):

diff -r c8a440cf1b54 -r 6c46e320a5e8 usr.sbin/tcpdump/print-udp.c
--- a/usr.sbin/tcpdump/print-udp.c      Tue Aug 01 17:34:00 2000 +0000
+++ b/usr.sbin/tcpdump/print-udp.c      Tue Aug 01 17:35:18 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: print-udp.c,v 1.13 1999/12/10 05:45:08 itojun Exp $    */
+/*     $NetBSD: print-udp.c,v 1.14 2000/08/01 17:35:18 itojun Exp $    */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
@@ -27,7 +27,7 @@
 static const char rcsid[] =
     "@(#) Header: print-udp.c,v 1.60 97/07/27 21:58:48 leres Exp  (LBL)";
 #else
-__RCSID("$NetBSD: print-udp.c,v 1.13 1999/12/10 05:45:08 itojun Exp $");
+__RCSID("$NetBSD: print-udp.c,v 1.14 2000/08/01 17:35:18 itojun Exp $");
 #endif
 #endif
 
@@ -318,7 +318,7 @@
        /* pseudo-header.. */
        phu.ph.len = htons(tlen);
        phu.ph.mbz = 0;
-       phu.ph.proto = ip->ip_p;
+       phu.ph.proto = IPPROTO_UDP;
        memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
        memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
 
@@ -341,6 +341,53 @@
        return (sum);
 }
 
+#ifdef INET6
+static int udp6_cksum(const struct ip6_hdr *ip6, const struct udphdr *up,
+       int len)
+{
+       int i, tlen;
+       register const u_int16_t *sp;
+       u_int32_t sum;
+       union {
+               struct {
+                       struct in6_addr ph_src;
+                       struct in6_addr ph_dst;
+                       u_int32_t       ph_len;
+                       u_int8_t        ph_zero[3];
+                       u_int8_t        ph_nxt;
+               } ph;
+               u_int16_t pa[20];
+       } phu;
+
+       tlen = ntohs(ip6->ip6_plen) + sizeof(struct ip6_hdr) -
+           ((const char *)up - (const char*)ip6);
+
+       /* pseudo-header */
+       memset(&phu, 0, sizeof(phu));
+       phu.ph.ph_src = ip6->ip6_src;
+       phu.ph.ph_dst = ip6->ip6_dst;
+       phu.ph.ph_len = htonl(tlen);
+       phu.ph.ph_nxt = IPPROTO_UDP;
+
+       sum = 0;
+       for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++)
+               sum += phu.pa[i];
+
+       sp = (const u_int16_t *)up;
+
+       for (i = 0; i < (tlen & ~1); i += 2)
+               sum += *sp++;
+
+       if (tlen & 1)
+               sum += htons((*(const char *)sp) << 8);
+
+       while (sum > 0xffff)
+               sum = (sum & 0xffff) + (sum >> 16);
+       sum = ~sum & 0xffff;
+
+       return (sum);
+}
+#endif
 
 
 /* XXX probably should use getservbyname() and cache answers */
@@ -532,6 +579,19 @@
                                (void)printf(" [udp sum ok]");
                }
        }
+#ifdef INET6
+       if (ip->ip_v == 6 && ip6->ip6_plen && vflag) {
+               int sum = up->uh_sum;
+               /* for IPv6, UDP checksum is mandatory */
+               if (TTEST2(cp[0], length)) {
+                       sum = udp6_cksum(ip6, up, length);
+                       if (sum != 0)
+                               (void)printf(" [bad udp cksum %x!]", sum);
+                       else
+                               (void)printf(" [udp sum ok]");
+               }
+       }
+#endif
 
        if (!qflag) {
 #define ISPORT(p) (dport == (p) || sport == (p))