UDP-Lite fixes

[bz]

Summary

In the UDP over IPv6 implementation several cases are using the wrong protocol, e.g., based on wrong "next header" assumptions (which does not have to point to the upper layer protocol), or using hard-coded UDP instead of UDP or UDP-Lite switching protocols.
Fix those cases for UDP-Lite it to work correctly.

PR: 202788
Submitted by: Tiwei Bie (btw mail.ustc.edu.cn) (one part)
MFC After: 2 weeks

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=202788

[kevlo]

You're right, we should use "proto" to get the UDP or UDP-Lite.
Thanks for fixing it.

[btw]

sys/netinet6/udp6_usrreq.c

1236 ↗

(On Diff #8813)

If we are going to replace the hard-coded UDP used in ip_protox[]
with UDP or UDP-Lite switching protocols, should we do that in all
cases? (I know UDP and UDP-Lite share udp_usrreqs)

Such as these codes:

static void
udp6_abort(struct socket *so)
{
	......

#ifdef INET
	if (inp->inp_vflag & INP_IPV4) {
		struct pr_usrreqs *pru;

		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
		(*pru->pru_abort)(so);
		return;
	}
#endif
	......
}

static void
udp6_close(struct socket *so)
{
	......

#ifdef INET
	if (inp->inp_vflag & INP_IPV4) {
		struct pr_usrreqs *pru;

		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
		(*pru->pru_disconnect)(so);
		return;
	}
#endif

	......
}

static int
udp6_disconnect(struct socket *so)
{
	......

#ifdef INET
	if (inp->inp_vflag & INP_IPV4) {
		struct pr_usrreqs *pru;

		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
		(void)(*pru->pru_disconnect)(so);
		return (0);
	}
#endif

	......

}

Thanks! :-)

[bz]

Update for all ip_protox[] cases.

[bz]

Updated to catch the other 3.