Hi Jason,
Thanks very much for your response!
I check the ping & traceroute code, For ping:
if (options & F_TTL) {
if (IN_MULTICAST(ntohl(dst4.sin_addr.s_addr)))
moptions |= MULTICAST_TTL;
else
options |= F_HDRINCL;
}
For traceroute:
void
check_tos(struct ip *ip, int *last_tos)
{
struct icmp *icp;
struct ip *inner_ip;
icp = (struct icmp *) (((u_char *)ip)+(ip->ip_hl<<2));
inner_ip = (struct ip *) (((u_char *)icp)+8);
if (inner_ip->ip_tos != *last_tos)
printf (" (TOS=%d!)", inner_ip->ip_tos);
*last_tos = inner_ip->ip_tos;
}
They indeed don't handle IPv6. But for netcat, it actually hangle IPv6
case at leaet from code in preceding mail. If netcat doesn't want to
handle IPv6 intentionally, I think the IPv6 code should be removed,
thanks!
Best Regards
Nan Xiao
On Thu, Sep 20, 2018 at 7:45 PM Jason McIntyre <j...@kerhand.co.uk> wrote:
>
> On Wed, Sep 19, 2018 at 06:35:13PM +0800, Nan Xiao wrote:
> > Hi tech@,
> >
> > For `-T' option explanation in netcat manual:
> >
> > -T keyword
> > Change the IPv4 TOS value or the TLS options.
> >
> > But in fact, the netcat code not only processes IPv4 but also IPv6:
> >
> > if (Tflag != -1) {
> > if (af == AF_INET && setsockopt(s, IPPROTO_IP,
> > IP_TOS, &Tflag, sizeof(Tflag)) == -1)
> > err(1, "set IP ToS");
> >
> > else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6,
> > IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1)
> > err(1, "set IPv6 traffic class");
> > }
> >
> > So I think maybe the netcat manual should be enriched at least for `-T'
> > option, thanks!
> >
>
> hi.
>
> i think if you submit a diff, there will be a better chance of getting
> an ok (or otherwise).
>
> i'm unsure about -T myself. i know that we synced the -T options for
> ping/nc/traceroute to keep them in sync with pf, but none of those other
> docs claim support for ip6 classes - actually quite the opposite.
> so i'm unsure if they work (have you tested?) or whether we want to
> document them.
>
> jmc
>
