Implement proxy ARP for ART based on mpath support.

Since mpath is not enabled in RAMDISK, proxy ARP won't work there either.

ok bluhm@

5 files changed, 63 insertions, 12 deletions

diff --git a/sys/net/route.h b/sys/net/route.h
index 15b76bfed3d..bef35438642 100644
--- a/sys/net/route.h
+++ b/sys/net/route.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: route.h,v 1.133 2016/03/26 21:56:04 mpi Exp $	*/
+/*	$OpenBSD: route.h,v 1.134 2016/03/30 10:13:14 mpi Exp $	*/
 /*	$NetBSD: route.h,v 1.9 1996/02/13 22:00:49 christos Exp $	*/
 
 /*
@@ -136,6 +136,7 @@ struct rtentry {
 #define RTF_BLACKHOLE	0x1000		/* just discard pkts (during updates) */
 #define RTF_PROTO3	0x2000		/* protocol specific routing flag */
 #define RTF_PROTO2	0x4000		/* protocol specific routing flag */
+#define RTF_ANNOUNCE	RTF_PROTO2	/* announce L2 entry */
 #define RTF_PROTO1	0x8000		/* protocol specific routing flag */
 #define RTF_CLONED	0x10000		/* this is a cloned route */
 #define RTF_MPATH	0x40000		/* multipath route or operation */
diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index 008d91e0a77..11ef5246a4c 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rtsock.c,v 1.187 2016/03/26 21:56:04 mpi Exp $	*/
+/*	$OpenBSD: rtsock.c,v 1.188 2016/03/30 10:13:14 mpi Exp $	*/
 /*	$NetBSD: rtsock.c,v 1.18 1996/03/29 00:32:10 cgd Exp $	*/
 
 /*
@@ -98,6 +98,7 @@ struct walkarg {
 
 int	route_ctloutput(int, struct socket *, int, int, struct mbuf **);
 void	route_input(struct mbuf *m0, ...);
+int	route_arp_conflict(struct rt_addrinfo *, unsigned int);
 
 struct mbuf	*rt_msg1(int, struct rt_addrinfo *);
 int		 rt_msg2(int, int, struct rt_addrinfo *, caddr_t,
@@ -600,6 +601,8 @@ route_output(struct mbuf *m, ...)
 			error = EINVAL;
 			goto flush;
 		}
+		if ((error = route_arp_conflict(&info, tableid)))
+			goto flush;
 		error = rtrequest(RTM_ADD, &info, prio, &saved_nrt, tableid);
 		if (error == 0) {
 			rt_setmetrics(rtm->rtm_inits, &rtm->rtm_rmx,
@@ -886,6 +889,47 @@ fail:
 	return (error);
 }
 
+/*
+ * Check if the user request to insert an ARP entry does not conflict
+ * with existing ones.
+ *
+ * Only two entries are allowed for a given IP address: a private one
+ * (priv) and a public one (pub).
+ */
+int
+route_arp_conflict(struct rt_addrinfo *info, unsigned int tableid)
+{
+#if defined(ART) && !defined(SMALL_KERNEL)
+	struct rtentry	*rt;
+	int		 proxy = (info->rti_flags & RTF_ANNOUNCE);
+
+	if ((info->rti_flags & RTF_LLINFO) == 0 ||
+	    (info->rti_info[RTAX_DST]->sa_family != AF_INET))
+		return (0);
+
+	rt = rtalloc(info->rti_info[RTAX_DST], 0, tableid);
+	if (rt == NULL || !ISSET(rt->rt_flags, RTF_LLINFO)) {
+		rtfree(rt);
+		return (0);
+	}
+
+	/*
+	 * Same destination and both "priv" or "pub" conflict.
+	 * If a second entry exists, it always conflict.
+	 */
+	if ((ISSET(rt->rt_flags, RTF_ANNOUNCE) == proxy) ||
+	    (rtable_mpath_next(rt) != NULL)) {
+		rtfree(rt);
+		return (EEXIST);
+	}
+
+	/* No conflict but an entry exist so we need to force mpath. */
+	info->rti_flags |= RTF_MPATH;
+	rtfree(rt);
+#endif /* ART && !SMALL_KERNEL */
+	return (0);
+}
+
 void
 rt_setmetrics(u_long which, struct rt_metrics *in, struct rt_kmetrics *out)
 {
diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c
index 50095387798..ca7fea72be9 100644
--- a/sys/netinet/if_ether.c
+++ b/sys/netinet/if_ether.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ether.c,v 1.203 2016/03/24 07:15:10 mpi Exp $	*/
+/*	$OpenBSD: if_ether.c,v 1.204 2016/03/30 10:13:14 mpi Exp $	*/
 /*	$NetBSD: if_ether.c,v 1.31 1996/05/11 12:59:58 mycroft Exp $	*/
 
 /*
@@ -698,8 +698,20 @@ arplookup(u_int32_t addr, int create, int proxy, u_int tableid)
 	}
 
 	if (proxy && !ISSET(rt->rt_flags, RTF_ANNOUNCE)) {
+		struct rtentry *mrt = NULL;
+#if defined(ART) && !defined(SMALL_KERNEL)
+		mrt = rt;
+		KERNEL_LOCK();
+		while ((mrt = rtable_mpath_next(mrt)) != NULL) {
+			if (ISSET(mrt->rt_flags, RTF_ANNOUNCE)) {
+				rtref(mrt);
+				break;
+			}
+		}
+		KERNEL_UNLOCK();
+#endif /* ART && !SMALL_KERNEL */
 		rtfree(rt);
-		return (NULL);
+		return (mrt);
 	}
 
 	return (rt);
diff --git a/sys/netinet/if_ether.h b/sys/netinet/if_ether.h
index 365693b0103..a6e5fc1bd01 100644
--- a/sys/netinet/if_ether.h
+++ b/sys/netinet/if_ether.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ether.h,v 1.69 2016/03/16 11:48:27 dlg Exp $	*/
+/*	$OpenBSD: if_ether.h,v 1.70 2016/03/30 10:13:14 mpi Exp $	*/
 /*	$NetBSD: if_ether.h,v 1.22 1996/05/11 13:00:00 mycroft Exp $	*/
 
 /*
@@ -148,7 +148,6 @@ struct sockaddr_inarp {
  * IP and ethernet specific routing flags
  */
 #define	RTF_USETRAILERS	  RTF_PROTO1	/* use trailers */
-#define	RTF_ANNOUNCE	  RTF_PROTO2	/* announce new arp entry */
 #define	RTF_PERMANENT_ARP RTF_PROTO3    /* only manual overwrite of entry */
 
 #ifdef _KERNEL
diff --git a/sys/netinet6/nd6.h b/sys/netinet6/nd6.h
index 1f534d02d04..80e91781fa9 100644
--- a/sys/netinet6/nd6.h
+++ b/sys/netinet6/nd6.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6.h,v 1.57 2016/03/03 12:57:15 jca Exp $	*/
+/*	$OpenBSD: nd6.h,v 1.58 2016/03/30 10:13:14 mpi Exp $	*/
 /*	$KAME: nd6.h,v 1.95 2002/06/08 11:31:06 itojun Exp $	*/
 
 /*
@@ -35,11 +35,6 @@
 
 #include <sys/task.h>
 
-/* see net/route.h, or net/if_inarp.h */
-#ifndef RTF_ANNOUNCE
-#define RTF_ANNOUNCE	RTF_PROTO2
-#endif
-
 #define ND6_LLINFO_PURGE	-3
 #define ND6_LLINFO_NOSTATE	-2
 #define ND6_LLINFO_INCOMPLETE	0