[src/trunk]: src/sys/netinet reject packets with 127/8 on IPv4 src/dst, they ...

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

details:   https://anonhg.NetBSD.org/src/rev/99d91d1a021e
branches:  trunk
changeset: 504416:99d91d1a021e
user:      itojun <itojun%NetBSD.org@localhost>
date:      Fri Mar 02 02:05:36 2001 +0000

description:
reject packets with 127/8 on IPv4 src/dst, they must not appear on wire
(RFC1122).  torture-tests will be welcomed.
XXX do we want to check source routing headers as well?

diffstat:

 sys/netinet/ip_input.c |  9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diffs (23 lines):

diff -r 07c427e0275b -r 99d91d1a021e sys/netinet/ip_input.c
--- a/sys/netinet/ip_input.c    Fri Mar 02 01:46:57 2001 +0000
+++ b/sys/netinet/ip_input.c    Fri Mar 02 02:05:36 2001 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ip_input.c,v 1.128 2001/03/01 16:31:39 itojun Exp $    */
+/*     $NetBSD: ip_input.c,v 1.129 2001/03/02 02:05:36 itojun Exp $    */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -418,6 +418,13 @@
                goto bad;
        }
 
+       /* 127/8 must not appear on wire - RFC1122 */
+       if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
+           (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
+               if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0)
+                       goto bad;
+       }
+
        if (in_cksum(m, hlen) != 0) {
                ipstat.ips_badsum++;
                goto bad;