Remove linkmtu and maxmtu from struct nd_ifinfo. IN6_LINKMTU can now

die and ifp->if_mtu is the one true mtu.
Suggested by and OK mpi@

9 files changed, 23 insertions, 149 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index e433dcf9dba..3537e85245c 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.c,v 1.399 2015/10/27 10:52:17 mpi Exp $	*/
+/*	$OpenBSD: if.c,v 1.400 2015/10/28 12:14:25 florian Exp $	*/
 /*	$NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $	*/
 
 /*
@@ -1734,26 +1734,12 @@ ifioctl(struct socket *so, u_long cmd, caddr_t data, struct proc *p)
 		break;
 
 	case SIOCSIFMTU:
-	{
-#ifdef INET6
-		int oldmtu = ifp->if_mtu;
-#endif
-
 		if ((error = suser(p, 0)) != 0)
 			return (error);
 		if (ifp->if_ioctl == NULL)
 			return (EOPNOTSUPP);
 		error = (*ifp->if_ioctl)(ifp, cmd, data);
-
-		/*
-		 * If the link MTU changed, do network layer specific procedure.
-		 */
-#ifdef INET6
-		if (ifp->if_mtu != oldmtu)
-			nd6_setmtu(ifp);
-#endif
 		break;
-	}
 
 	case SIOCSIFPHYADDR:
 	case SIOCDIFPHYADDR:
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index a77cc639190..287a45a4881 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_input.c,v 1.306 2015/10/24 16:08:48 mpi Exp $	*/
+/*	$OpenBSD: tcp_input.c,v 1.307 2015/10/28 12:14:25 florian Exp $	*/
 /*	$NetBSD: tcp_input.c,v 1.23 1996/02/13 23:43:44 christos Exp $	*/
 
 /*
@@ -3045,22 +3045,13 @@ tcp_mss(struct tcpcb *tp, int offer)
 		 * for IPv6, path MTU discovery is always turned on,
 		 * or the node must use packet size <= 1280.
 		 */
-		mss = IN6_LINKMTU(ifp) - iphlen - sizeof(struct tcphdr);
+		mss = ifp->if_mtu - iphlen - sizeof(struct tcphdr);
 	}
 #endif /* INET6 */
 
 	/* Calculate the value that we offer in TCPOPT_MAXSEG */
 	if (offer != -1) {
-#ifndef INET6
 		mssopt = ifp->if_mtu - iphlen - sizeof(struct tcphdr);
-#else
-		if (tp->pf == AF_INET6)
-			mssopt = IN6_LINKMTU(ifp) - iphlen -
-			    sizeof(struct tcphdr);
-		else
-			mssopt = ifp->if_mtu - iphlen - sizeof(struct tcphdr);
-#endif
-
 		mssopt = max(tcp_mssdflt, mssopt);
 	}
 
@@ -3272,7 +3263,7 @@ tcp_mss_adv(struct mbuf *m, int af)
 #ifdef INET6
 	case AF_INET6:
 		if (ifp != NULL)
-			mss = IN6_LINKMTU(ifp);
+			mss = ifp->if_mtu;
 		iphlen = sizeof(struct ip6_hdr);
 		break;
 #endif  
diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c
index 4f7034cbb84..d87678240fa 100644
--- a/sys/netinet6/icmp6.c
+++ b/sys/netinet6/icmp6.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: icmp6.c,v 1.174 2015/10/22 15:37:47 bluhm Exp $	*/
+/*	$OpenBSD: icmp6.c,v 1.175 2015/10/28 12:14:25 florian Exp $	*/
 /*	$KAME: icmp6.c,v 1.217 2001/06/20 15:03:29 jinmei Exp $	*/
 
 /*
@@ -1022,7 +1022,7 @@ icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
 	if (rt && (rt->rt_flags & RTF_HOST) &&
 	    !(rt->rt_rmx.rmx_locks & RTV_MTU) &&
 	    (rt->rt_rmx.rmx_mtu > mtu || rt->rt_rmx.rmx_mtu == 0)) {
-		if (mtu < IN6_LINKMTU(rt->rt_ifp)) {
+		if (mtu < rt->rt_ifp->if_mtu) {
 			icmp6stat.icp6s_pmtuchg++;
 			rt->rt_rmx.rmx_mtu = mtu;
 		}
diff --git a/sys/netinet6/ip6_forward.c b/sys/netinet6/ip6_forward.c
index d6a74dc2b01..6fc2bb250cc 100644
--- a/sys/netinet6/ip6_forward.c
+++ b/sys/netinet6/ip6_forward.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip6_forward.c,v 1.84 2015/10/25 15:01:59 mpi Exp $	*/
+/*	$OpenBSD: ip6_forward.c,v 1.85 2015/10/28 12:14:25 florian Exp $	*/
 /*	$KAME: ip6_forward.c,v 1.75 2001/06/29 12:42:13 jinmei Exp $	*/
 
 /*
@@ -426,14 +426,10 @@ reroute:
 	in6_proto_cksum_out(m, rt->rt_ifp);
 
 	/* Check the size after pf_test to give pf a chance to refragment. */
-	if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) {
-		if (mcopy) {
-			u_long mtu;
-
-			mtu = IN6_LINKMTU(rt->rt_ifp);
-
-			icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu);
-		}
+	if (m->m_pkthdr.len > rt->rt_ifp->if_mtu) {
+		if (mcopy)
+			icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0,
+			    rt->rt_ifp->if_mtu);
 		m_freem(m);
 		goto freert;
 	}
diff --git a/sys/netinet6/ip6_mroute.c b/sys/netinet6/ip6_mroute.c
index 0474319fc53..22be5890e39 100644
--- a/sys/netinet6/ip6_mroute.c
+++ b/sys/netinet6/ip6_mroute.c
@@ -1512,7 +1512,6 @@ phyint_send6(struct ip6_hdr *ip6, struct mif6 *mifp, struct mbuf *m)
 	static struct route_in6 ro;
 	struct	in6_multi *in6m;
 	struct sockaddr_in6 *dst6;
-	u_long linkmtu;
 
 	/*
 	 * Make a new reference to the packet; make sure that
@@ -1572,8 +1571,7 @@ phyint_send6(struct ip6_hdr *ip6, struct mif6 *mifp, struct mbuf *m)
 	 * Put the packet into the sending queue of the outgoing interface
 	 * if it would fit in the MTU of the interface.
 	 */
-	linkmtu = IN6_LINKMTU(ifp);
-	if (mb_copy->m_pkthdr.len <= linkmtu || linkmtu < IPV6_MMTU) {
+	if (mb_copy->m_pkthdr.len <= ifp->if_mtu || ifp->if_mtu < IPV6_MMTU) {
 		dst6->sin6_len = sizeof(struct sockaddr_in6);
 		dst6->sin6_family = AF_INET6;
 		dst6->sin6_addr = ip6->ip6_dst;
@@ -1590,7 +1588,8 @@ phyint_send6(struct ip6_hdr *ip6, struct mif6 *mifp, struct mbuf *m)
 #endif
 	} else {
 		if (ip6_mcast_pmtu)
-			icmp6_error(mb_copy, ICMP6_PACKET_TOO_BIG, 0, linkmtu);
+			icmp6_error(mb_copy, ICMP6_PACKET_TOO_BIG, 0,
+			    ifp->if_mtu);
 		else {
 #ifdef MRT6DEBUG
 			char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN];
diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
index 2fa1c68a4cd..eeac95d66a4 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip6_output.c,v 1.192 2015/10/25 14:43:06 florian Exp $	*/
+/*	$OpenBSD: ip6_output.c,v 1.193 2015/10/28 12:14:25 florian Exp $	*/
 /*	$KAME: ip6_output.c,v 1.172 2001/03/25 09:55:56 itojun Exp $	*/
 
 /*
@@ -772,26 +772,7 @@ reroute:
 		error = EMSGSIZE;
 		goto bad;
 	}
-	if (dontfrag && tlen > IN6_LINKMTU(ifp)) {	/* case 2-b */
-		/*
-		 * Even if the DONTFRAG option is specified, we cannot send the
-		 * packet when the data length is larger than the MTU of the
-		 * outgoing interface.
-		 * Notify the error by sending IPV6_PATHMTU ancillary data as
-		 * well as returning an error code (the latter is not described
-		 * in the API spec.)
-		 */
-#if 0
-		u_int32_t mtu32;
-		struct ip6ctlparam ip6cp;
-
-		mtu32 = (u_int32_t)mtu;
-		bzero(&ip6cp, sizeof(ip6cp));
-		ip6cp.ip6c_cmdarg = (void *)&mtu32;
-		pfctlinput2(PRC_MSGSIZE, sin6tosa(&ro_pmtu->ro_dst),
-		    (void *)&ip6cp);
-#endif
-
+	if (dontfrag && tlen > ifp->if_mtu) {	/* case 2-b */
 		error = EMSGSIZE;
 		goto bad;
 	}
@@ -1161,14 +1142,11 @@ ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
 		}
 	}
 	if (ro_pmtu->ro_rt) {
-		u_int32_t ifmtu;
-
 		if (ifp == NULL)
 			ifp = ro_pmtu->ro_rt->rt_ifp;
-		ifmtu = IN6_LINKMTU(ifp);
 		mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
 		if (mtu == 0)
-			mtu = ifmtu;
+			mtu = ifp->if_mtu;
 		else if (mtu < IPV6_MMTU) {
 			/*
 			 * RFC2460 section 5, last paragraph:
@@ -1180,7 +1158,7 @@ ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
 			 */
 			alwaysfrag = 1;
 			mtu = IPV6_MMTU;
-		} else if (mtu > ifmtu) {
+		} else if (mtu > ifp->if_mtu) {
 			/*
 			 * The MTU on the route is larger than the MTU on
 			 * the interface!  This shouldn't happen, unless the
@@ -1189,12 +1167,12 @@ ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
 			 * route to match the interface MTU (as long as the
 			 * field isn't locked).
 			 */
-			mtu = ifmtu;
+			mtu = ifp->if_mtu;
 			if (!(ro_pmtu->ro_rt->rt_rmx.rmx_locks & RTV_MTU))
 				ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
 		}
 	} else if (ifp) {
-		mtu = IN6_LINKMTU(ifp);
+		mtu = ifp->if_mtu;
 	} else
 		error = EHOSTUNREACH; /* XXX */
 
diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index c065406742d..3507a125503 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6.c,v 1.163 2015/10/27 10:52:18 mpi Exp $	*/
+/*	$OpenBSD: nd6.c,v 1.164 2015/10/28 12:14:25 florian Exp $	*/
 /*	$KAME: nd6.c,v 1.280 2002/06/08 19:52:07 itojun Exp $	*/
 
 /*
@@ -90,7 +90,6 @@ struct nd_prhead nd_prefix = { 0 };
 
 int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
 
-void nd6_setmtu0(struct ifnet *, struct nd_ifinfo *);
 void nd6_slowtimo(void *);
 struct llinfo_nd6 *nd6_free(struct rtentry *, int);
 void nd6_llinfo_timer(void *);
@@ -153,9 +152,6 @@ nd6_ifattach(struct ifnet *ifp)
 	/* per-interface IFXF_AUTOCONF6 needs to be set too to accept RAs */
 	nd->flags = (ND6_IFF_PERFORMNUD | ND6_IFF_ACCEPT_RTADV);
 
-	/* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
-	nd6_setmtu0(ifp, nd);
-
 	return nd;
 }
 
@@ -167,32 +163,6 @@ nd6_ifdetach(struct nd_ifinfo *nd)
 }
 
 void
-nd6_setmtu(struct ifnet *ifp)
-{
-	nd6_setmtu0(ifp, ND_IFINFO(ifp));
-}
-
-void
-nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi)
-{
-	u_int32_t omaxmtu;
-
-	omaxmtu = ndi->maxmtu;
-	ndi->maxmtu = ifp->if_mtu;
-
-	/*
-	 * Decreasing the interface MTU under IPV6 minimum MTU may cause
-	 * undesirable situation.  We thus notify the operator of the change
-	 * explicitly.  The check for omaxmtu is necessary to restrict the
-	 * log to the case of changing the MTU, not initializing it.
-	 */
-	if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
-		log(LOG_NOTICE, "%s: link MTU on %s (%lu) too small for IPv6\n",
-		    __func__, ifp->if_xname, (unsigned long)ndi->maxmtu);
-	}
-}
-
-void
 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
 {
 	bzero(ndopts, sizeof(*ndopts));
diff --git a/sys/netinet6/nd6.h b/sys/netinet6/nd6.h
index 03ad2db22af..6ecd4dcb24d 100644
--- a/sys/netinet6/nd6.h
+++ b/sys/netinet6/nd6.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6.h,v 1.51 2015/10/25 11:58:11 mpi Exp $	*/
+/*	$OpenBSD: nd6.h,v 1.52 2015/10/28 12:14:25 florian Exp $	*/
 /*	$KAME: nd6.h,v 1.95 2002/06/08 11:31:06 itojun Exp $	*/
 
 /*
@@ -49,8 +49,6 @@
 #define ND6_LLINFO_PROBE	4
 
 struct nd_ifinfo {
-	u_int32_t linkmtu;		/* LinkMTU */
-	u_int32_t maxmtu;		/* Upper bound of LinkMTU */
 	u_int32_t basereachable;	/* BaseReachableTime */
 	u_int32_t reachable;		/* Reachable Time */
 	u_int32_t retrans;		/* Retrans Timer */
@@ -136,13 +134,6 @@ struct	in6_ndifreq {
 #define RS_LHCOOKIE(ifp) \
 	((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->rs_lhcookie
 
-#define IN6_LINKMTU(ifp) \
-	((ND_IFINFO(ifp)->linkmtu && ND_IFINFO(ifp)->linkmtu < (ifp)->if_mtu) \
-	    ? ND_IFINFO(ifp)->linkmtu \
-	    : ((ND_IFINFO(ifp)->maxmtu && ND_IFINFO(ifp)->maxmtu < (ifp)->if_mtu) \
-		? ND_IFINFO(ifp)->maxmtu : (ifp)->if_mtu))
-
-
 struct	llinfo_nd6 {
 	struct	llinfo_nd6 *ln_next;
 	struct	llinfo_nd6 *ln_prev;
diff --git a/sys/netinet6/nd6_rtr.c b/sys/netinet6/nd6_rtr.c
index d13f7a01526..e5533a513e7 100644
--- a/sys/netinet6/nd6_rtr.c
+++ b/sys/netinet6/nd6_rtr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6_rtr.c,v 1.129 2015/10/25 21:32:16 florian Exp $	*/
+/*	$OpenBSD: nd6_rtr.c,v 1.130 2015/10/28 12:14:25 florian Exp $	*/
 /*	$KAME: nd6_rtr.c,v 1.97 2001/02/07 11:09:13 itojun Exp $	*/
 
 /*
@@ -529,43 +529,6 @@ nd6_ra_input(struct mbuf *m, int off, int icmp6len)
 	}
 
 	/*
-	 * MTU
-	 */
-	if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
-		u_long mtu;
-		u_long maxmtu;
-
-		mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
-
-		/* lower bound */
-		if (mtu < IPV6_MMTU) {
-			nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
-			    "mtu=%lu sent from %s, ignoring\n",
-			    mtu,
-			    inet_ntop(AF_INET6, &ip6->ip6_src,
-				src, sizeof(src))));
-			goto skip;
-		}
-
-		/* upper bound */
-		maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu)
-		    ? ndi->maxmtu : ifp->if_mtu;
-		if (mtu <= maxmtu) {
-			ndi->linkmtu = mtu;
-		} else {
-			nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
-			    "mtu=%lu sent from %s; "
-			    "exceeds maxmtu %lu, ignoring\n",
-			    mtu,
-			    inet_ntop(AF_INET6, &ip6->ip6_src,
-				src, sizeof(src)),
-			    maxmtu));
-		}
-	}
-
- skip:
-
-	/*
 	 * Source link layer address
 	 */
     {