From: mpi <mpi@openbsd.org>
Date: Mon, 5 May 2014 11:44:33 +0000 (+0000)
Subject: Use a custom ifa_rtrequest function for point-to-point interfaces
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=7da1c79582926d7bf5db9de050dc83d671827eff;p=openbsd

Use a custom ifa_rtrequest function for point-to-point interfaces
instead of relying on hacks in nd6_rtrequest() to add a route to
loopback for each address configured on such interfaces.

While here document that abusing lo0 for local traffic is not safe
for interfaces in a non-default rdomain.

Tested by claudio@, jca@ and sthen@, ok sthen@
---

diff --git a/sys/net/if.c b/sys/net/if.c
index 5f35a6d5a37..95709aec76a 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.c,v 1.286 2014/04/22 12:35:00 mpi Exp $	*/
+/*	$OpenBSD: if.c,v 1.287 2014/05/05 11:44:33 mpi Exp $	*/
 /*	$NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $	*/
 
 /*
@@ -989,6 +989,71 @@ link_rtrequest(int cmd, struct rtentry *rt)
 	}
 }
 
+/*
+ * Default action when installing a local route on a point-to-point
+ * interface.
+ */
+void
+p2p_rtrequest(int req, struct rtentry *rt)
+{
+	struct ifnet *ifp = rt->rt_ifp;
+	struct ifaddr *ifa, *lo0ifa;
+
+	switch (req) {
+	case RTM_ADD:
+		/*
+		 * XXX Here we abuse RTF_LLINFO to add a route to
+		 * loopback.  We do that to always have a route
+		 * pointing to our address.
+		 */
+		if ((rt->rt_flags & RTF_LLINFO) == 0)
+			break;
+
+		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
+			if (memcmp(rt_key(rt), ifa->ifa_addr,
+			    rt_key(rt)->sa_len) == 0)
+				break;
+		}
+
+		if (ifa == NULL)
+			break;
+
+		/*
+		 * XXX Since lo0 is in the default rdomain we should not
+		 * (ab)use it for any route related to an interface of a
+		 * different rdomain.
+		 */
+		TAILQ_FOREACH(lo0ifa, &lo0ifp->if_addrlist, ifa_list)
+			if (lo0ifa->ifa_addr->sa_family ==
+			    ifa->ifa_addr->sa_family)
+				break;
+
+		if (lo0ifa == NULL)
+			break;
+
+		rt_setgate(rt, rt_key(rt), lo0ifa->ifa_addr, ifp->if_rdomain);
+		rt->rt_ifp = lo0ifp;
+		rt->rt_flags &= ~RTF_LLINFO;
+
+		/*
+		 * make sure to set rt->rt_ifa to the interface
+		 * address we are using, otherwise we will have trouble
+		 * with source address selection.
+		 */
+		if (ifa != rt->rt_ifa) {
+			ifafree(rt->rt_ifa);
+			ifa->ifa_refcnt++;
+			rt->rt_ifa = ifa;
+		}
+		break;
+	case RTM_DELETE:
+	case RTM_RESOLVE:
+	default:
+		break;
+	}
+}
+
+
 /*
  * Bring down all interfaces
  */
diff --git a/sys/net/if_gif.c b/sys/net/if_gif.c
index ec0ba137193..264e83c6325 100644
--- a/sys/net/if_gif.c
+++ b/sys/net/if_gif.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_gif.c,v 1.66 2014/04/21 12:22:25 henning Exp $	*/
+/*	$OpenBSD: if_gif.c,v 1.67 2014/05/05 11:44:33 mpi Exp $	*/
 /*	$KAME: if_gif.c,v 1.43 2001/02/20 08:51:07 itojun Exp $	*/
 
 /*
@@ -354,7 +354,8 @@ int
 gif_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 {
 	struct gif_softc *sc  = (struct gif_softc*)ifp;
-	struct ifreq     *ifr = (struct ifreq*)data;
+	struct ifreq     *ifr = (struct ifreq *)data;
+	struct ifaddr	 *ifa = (struct ifaddr *)data;
 	int error = 0, size;
 	struct sockaddr *dst, *src;
 	struct sockaddr *sa;
@@ -363,6 +364,7 @@ gif_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 
 	switch (cmd) {
 	case SIOCSIFADDR:
+		ifa->ifa_rtrequest = p2p_rtrequest;
 		break;
 
 	case SIOCSIFDSTADDR:
diff --git a/sys/net/if_gre.c b/sys/net/if_gre.c
index e42391092e9..3e58bc1ef08 100644
--- a/sys/net/if_gre.c
+++ b/sys/net/if_gre.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: if_gre.c,v 1.67 2014/04/21 12:22:25 henning Exp $ */
+/*      $OpenBSD: if_gre.c,v 1.68 2014/05/05 11:44:33 mpi Exp $ */
 /*	$NetBSD: if_gre.c,v 1.9 1999/10/25 19:18:11 drochner Exp $ */
 
 /*
@@ -441,7 +441,8 @@ int
 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 {
 
-	struct ifreq *ifr = (struct ifreq *) data;
+	struct ifreq *ifr = (struct ifreq *)data;
+	struct ifaddr *ifa = (struct ifaddr *)data;
 	struct if_laddrreq *lifr = (struct if_laddrreq *)data;
 	struct ifkalivereq *ikar = (struct ifkalivereq *)data;
 	struct gre_softc *sc = ifp->if_softc;
@@ -455,6 +456,7 @@ gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 	switch(cmd) {
 	case SIOCSIFADDR:
 		ifp->if_flags |= IFF_UP;
+		ifa->ifa_rtrequest = p2p_rtrequest;
 		break;
 	case SIOCSIFDSTADDR:
 		break;
diff --git a/sys/net/if_ppp.c b/sys/net/if_ppp.c
index ab1dad08965..5cb44e75ac4 100644
--- a/sys/net/if_ppp.c
+++ b/sys/net/if_ppp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ppp.c,v 1.73 2014/04/19 12:08:10 henning Exp $	*/
+/*	$OpenBSD: if_ppp.c,v 1.74 2014/05/05 11:44:33 mpi Exp $	*/
 /*	$NetBSD: if_ppp.c,v 1.39 1997/05/17 21:11:59 christos Exp $	*/
 
 /*
@@ -619,6 +619,7 @@ pppsioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
     case SIOCSIFADDR:
 	if (ifa->ifa_addr->sa_family != AF_INET)
 	    error = EAFNOSUPPORT;
+	ifa->ifa_rtrequest = p2p_rtrequest;
 	break;
 
     case SIOCSIFDSTADDR:
diff --git a/sys/net/if_pppx.c b/sys/net/if_pppx.c
index 37a971504ef..66b2a836043 100644
--- a/sys/net/if_pppx.c
+++ b/sys/net/if_pppx.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_pppx.c,v 1.29 2014/04/08 04:26:53 miod Exp $ */
+/*	$OpenBSD: if_pppx.c,v 1.30 2014/05/05 11:44:33 mpi Exp $ */
 
 /*
  * Copyright (c) 2010 Claudio Jeker <claudio@openbsd.org>
@@ -1094,10 +1094,14 @@ pppx_if_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)
 {
 	struct pppx_if *pxi = (struct pppx_if *)ifp->if_softc;
 	struct ifreq *ifr = (struct ifreq *)addr;
+	struct ifaddr *ifa = (struct ifaddr *)addr;
 	int error = 0;
 
 	switch (cmd) {
 	case SIOCSIFADDR:
+		ifa->ifa_rtrequest = p2p_rtrequest;
+		break;
+
 	case SIOCSIFFLAGS:
 		break;
 
diff --git a/sys/net/if_spppsubr.c b/sys/net/if_spppsubr.c
index d3b5f0ee462..afbced7c8c7 100644
--- a/sys/net/if_spppsubr.c
+++ b/sys/net/if_spppsubr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_spppsubr.c,v 1.122 2014/05/02 10:40:26 jca Exp $	*/
+/*	$OpenBSD: if_spppsubr.c,v 1.123 2014/05/05 11:44:33 mpi Exp $	*/
 /*
  * Synchronous PPP/Cisco link level subroutines.
  * Keepalive protocol implemented in both Cisco and PPP modes.
@@ -996,7 +996,8 @@ sppp_pick(struct ifnet *ifp)
 int
 sppp_ioctl(struct ifnet *ifp, u_long cmd, void *data)
 {
-	struct ifreq *ifr = (struct ifreq*) data;
+	struct ifreq *ifr = data;
+	struct ifaddr *ifa = data;
 	struct sppp *sp = (struct sppp*) ifp;
 	int s, rv, going_up, going_down, newmode;
 
@@ -1009,6 +1010,7 @@ sppp_ioctl(struct ifnet *ifp, u_long cmd, void *data)
 
 	case SIOCSIFADDR:
 		if_up(ifp);
+		ifa->ifa_rtrequest = p2p_rtrequest;
 		/* FALLTHROUGH */
 
 	case SIOCSIFFLAGS:
diff --git a/sys/net/if_tun.c b/sys/net/if_tun.c
index 3e9a6500972..7d705463df4 100644
--- a/sys/net/if_tun.c
+++ b/sys/net/if_tun.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_tun.c,v 1.124 2014/04/22 14:41:03 mpi Exp $	*/
+/*	$OpenBSD: if_tun.c,v 1.125 2014/05/05 11:44:33 mpi Exp $	*/
 /*	$NetBSD: if_tun.c,v 1.24 1996/05/07 02:40:48 thorpej Exp $	*/
 
 /*
@@ -469,6 +469,7 @@ tun_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 {
 	struct tun_softc	*tp = (struct tun_softc *)(ifp->if_softc);
 	struct ifreq		*ifr = (struct ifreq *)data;
+	struct ifaddr		*ifa = (struct ifaddr *)data;
 	int			 error = 0, s;
 
 	s = splnet();
@@ -477,16 +478,19 @@ tun_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 	case SIOCSIFADDR:
 		tuninit(tp);
 		TUNDEBUG(("%s: address set\n", ifp->if_xname));
-		if (tp->tun_flags & TUN_LAYER2)
-			switch (((struct ifaddr *)data)->ifa_addr->sa_family) {
+		if (tp->tun_flags & TUN_LAYER2) {
+			switch (ifa->ifa_addr->sa_family) {
 #ifdef INET
 			case AF_INET:
-				arp_ifinit(&tp->arpcom, (struct ifaddr *)data);
+				arp_ifinit(&tp->arpcom, ifa);
 				break;
 #endif
 			default:
 				break;
 			}
+		} else {
+			ifa->ifa_rtrequest = p2p_rtrequest;
+		}
 		break;
 	case SIOCSIFDSTADDR:
 		tuninit(tp);
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index 34061ae5862..0277f9d0234 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_var.h,v 1.9 2014/04/23 09:30:57 mpi Exp $	*/
+/*	$OpenBSD: if_var.h,v 1.10 2014/05/05 11:44:33 mpi Exp $	*/
 /*	$NetBSD: if.h,v 1.23 1996/05/07 02:40:27 thorpej Exp $	*/
 
 /*
@@ -428,6 +428,7 @@ struct	ifaddr *ifa_ifwithnet(struct sockaddr *, u_int);
 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
 void	ifafree(struct ifaddr *);
 void	link_rtrequest(int, struct rtentry *);
+void	p2p_rtrequest(int, struct rtentry *);
 
 void	if_clone_attach(struct if_clone *);
 void	if_clone_detach(struct if_clone *);
diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c
index 4286eaee5a9..2e8c294dd9d 100644
--- a/sys/netinet/if_ether.c
+++ b/sys/netinet/if_ether.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ether.c,v 1.125 2014/04/14 09:06:42 mpi Exp $	*/
+/*	$OpenBSD: if_ether.c,v 1.126 2014/05/05 11:44:33 mpi Exp $	*/
 /*	$NetBSD: if_ether.c,v 1.31 1996/05/11 12:59:58 mycroft Exp $	*/
 
 /*
@@ -254,6 +254,12 @@ arp_rtrequest(int req, struct rtentry *rt)
 			SDL(gate)->sdl_alen = ETHER_ADDR_LEN;
 			memcpy(LLADDR(SDL(gate)),
 			    ((struct arpcom *)ifp)->ac_enaddr, ETHER_ADDR_LEN);
+
+			/*
+			 * XXX Since lo0 is in the default rdomain we
+			 * should not (ab)use it for any route related
+			 * to an interface of a different rdomain.
+			 */
 			if (useloopback)
 				rt->rt_ifp = lo0ifp;
 			/*
diff --git a/sys/netinet6/in6.c b/sys/netinet6/in6.c
index 4dcdf1d2f84..300abd63c3c 100644
--- a/sys/netinet6/in6.c
+++ b/sys/netinet6/in6.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in6.c,v 1.135 2014/04/10 13:47:21 mpi Exp $	*/
+/*	$OpenBSD: in6.c,v 1.136 2014/05/05 11:44:33 mpi Exp $	*/
 /*	$KAME: in6.c,v 1.372 2004/06/14 08:14:21 itojun Exp $	*/
 
 /*
@@ -1369,7 +1369,8 @@ in6_ifinit(struct ifnet *ifp, struct in6_ifaddr *ia6, int newhost)
 		ifacount++;
 	}
 
-	if ((ifacount <= 1 || ifp->if_type == IFT_CARP) && ifp->if_ioctl &&
+	if ((ifacount <= 1 || ifp->if_type == IFT_CARP ||
+	    (ifp->if_flags & IFF_POINTOPOINT)) && ifp->if_ioctl &&
 	    (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia6))) {
 		splx(s);
 		return (error);
@@ -1398,7 +1399,9 @@ in6_ifinit(struct ifnet *ifp, struct in6_ifaddr *ia6, int newhost)
 	/* Add ownaddr as loopback rtentry, if necessary (ex. on p2p link). */
 	if (newhost) {
 		/* set the rtrequest function to create llinfo */
-		ia6->ia_ifa.ifa_rtrequest = nd6_rtrequest;
+		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
+			ia6->ia_ifa.ifa_rtrequest = nd6_rtrequest;
+
 		rt_ifa_addloop(&(ia6->ia_ifa));
 	}
 
diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index 70faed0b066..71a1aec6222 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6.c,v 1.114 2014/04/14 09:06:42 mpi Exp $	*/
+/*	$OpenBSD: nd6.c,v 1.115 2014/05/05 11:44:33 mpi Exp $	*/
 /*	$KAME: nd6.c,v 1.280 2002/06/08 19:52:07 itojun Exp $	*/
 
 /*
@@ -1157,8 +1157,14 @@ nd6_rtrequest(int req, struct rtentry *rt)
 				memcpy(LLADDR(SDL(gate)), macp, ifp->if_addrlen);
 				SDL(gate)->sdl_alen = ifp->if_addrlen;
 			}
+
+			/*
+			 * XXX Since lo0 is in the default rdomain we
+			 * should not (ab)use it for any route related
+			 * to an interface of a different rdomain.
+			 */
 			if (nd6_useloopback) {
-				rt->rt_ifp = lo0ifp;	/*XXX*/
+				rt->rt_ifp = lo0ifp;
 				/*
 				 * Make sure rt_ifa be equal to the ifaddr
 				 * corresponding to the address.