[src/trunk]: src/usr.sbin/rtadvd Set the hoplimit of 255 as specified in RFC ...

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

details:   https://anonhg.NetBSD.org/src/rev/28193e0e1896
branches:  trunk
changeset: 338711:28193e0e1896
user:      roy <roy%NetBSD.org@localhost>
date:      Fri Jun 05 14:15:41 2015 +0000

description:
Set the hoplimit of 255 as specified in RFC 4861 section 4.2
using the IPV6_MULTICAST_HOPS socket option rather than using CMSG
when constructing each message.

diffstat:

 usr.sbin/rtadvd/rtadvd.c |  21 +++++++++------------
 1 files changed, 9 insertions(+), 12 deletions(-)

diffs (42 lines):

diff -r 94fcc49f83ab -r 28193e0e1896 usr.sbin/rtadvd/rtadvd.c
--- a/usr.sbin/rtadvd/rtadvd.c  Fri Jun 05 14:09:20 2015 +0000
+++ b/usr.sbin/rtadvd/rtadvd.c  Fri Jun 05 14:15:41 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rtadvd.c,v 1.47 2015/06/05 14:09:20 roy Exp $  */
+/*     $NetBSD: rtadvd.c,v 1.48 2015/06/05 14:15:41 roy Exp $  */
 /*     $KAME: rtadvd.c,v 1.92 2005/10/17 14:40:02 suz Exp $    */
 
 /*
@@ -1518,6 +1518,14 @@
                exit(1);
        }
 
+       /* RFC 4861 Section 4.2 */
+       on = 255;
+       if (setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &on,
+                      sizeof(on)) == -1) {
+               syslog(LOG_ERR, "<%s> IPV6_MULTICAST_HOPS: %m", __func__);
+               exit(1);
+       }
+
        /* specify to tell receiving interface */
        on = 1;
 #ifdef IPV6_RECVPKTINFO
@@ -1693,17 +1701,6 @@
        memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));       /*XXX*/
        pi->ipi6_ifindex = rai->ifindex;
 
-       /* specify the hop limit of the packet */
-       {
-               int hoplimit = 255;
-
-               cm = CMSG_NXTHDR(&sndmhdr, cm);
-               cm->cmsg_level = IPPROTO_IPV6;
-               cm->cmsg_type = IPV6_HOPLIMIT;
-               cm->cmsg_len = CMSG_LEN(sizeof(int));
-               memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
-       }
-
        syslog(LOG_DEBUG,
               "<%s> send RA on %s, # of waitings = %d",
               __func__, rai->ifname, rai->waiting);