Use the route generation number also for IPv6.

Implement route6_cache() to check whether the cached route is still
valid and otherwise fill caching parameter of struct route_in6.
Also count cache hits and misses in netstat.  in_pcbrtentry() uses
route cache now.

OK claudio@

8 files changed, 68 insertions, 105 deletions

diff --git a/sys/net/route.c b/sys/net/route.c
index adb37198527..5a6f7aad6d8 100644
--- a/sys/net/route.c
+++ b/sys/net/route.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: route.c,v 1.428 2024/02/05 23:16:39 bluhm Exp $	*/
+/*	$OpenBSD: route.c,v 1.429 2024/02/07 23:40:40 bluhm Exp $	*/
 /*	$NetBSD: route.c,v 1.14 1996/02/13 22:00:46 christos Exp $	*/
 
 /*
@@ -230,6 +230,36 @@ route_cache(struct route *ro, struct in_addr addr, u_int rtableid)
 	satosin(&ro->ro_dst)->sin_addr = addr;
 }
 
+void
+route6_cache(struct route_in6 *ro, const struct in6_addr *addr,
+    u_int rtableid)
+{
+	u_long gen;
+
+	gen = atomic_load_long(&rtgeneration);
+	membar_consumer();
+
+	if (rtisvalid(ro->ro_rt) &&
+	    ro->ro_generation == gen &&
+	    ro->ro_tableid == rtableid &&
+	    ro->ro_dst.sin6_family == AF_INET6 &&
+	    IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, addr)) {
+		ip6stat_inc(ip6s_rtcachehit);
+		return;
+	}
+
+	ip6stat_inc(ip6s_rtcachemiss);
+	rtfree(ro->ro_rt);
+	ro->ro_rt = NULL;
+	ro->ro_generation = gen;
+	ro->ro_tableid = rtableid;
+
+	memset(&ro->ro_dst, 0, sizeof(ro->ro_dst));
+	ro->ro_dst.sin6_family = AF_INET6;
+	ro->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
+	ro->ro_dst.sin6_addr = *addr;
+}
+
 /*
  * Returns 1 if the (cached) ``rt'' entry is still valid, 0 otherwise.
  */
diff --git a/sys/netinet/in_pcb.c b/sys/netinet/in_pcb.c
index fd6417eead0..456135a722c 100644
--- a/sys/netinet/in_pcb.c
+++ b/sys/netinet/in_pcb.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in_pcb.c,v 1.289 2024/02/02 15:39:23 bluhm Exp $	*/
+/*	$OpenBSD: in_pcb.c,v 1.290 2024/02/07 23:40:40 bluhm Exp $	*/
 /*	$NetBSD: in_pcb.c,v 1.25 1996/02/13 23:41:53 christos Exp $	*/
 
 /*
@@ -916,24 +916,10 @@ in_pcbrtentry(struct inpcb *inp)
 
 	ro = &inp->inp_route;
 
-	/* check if route is still valid */
-	if (!rtisvalid(ro->ro_rt)) {
-		rtfree(ro->ro_rt);
-		ro->ro_rt = NULL;
-	}
-
-	/*
-	 * No route yet, so try to acquire one.
-	 */
+	if (inp->inp_faddr.s_addr == INADDR_ANY)
+		return (NULL);
+	route_cache(ro, inp->inp_faddr, inp->inp_rtableid);
 	if (ro->ro_rt == NULL) {
-		memset(ro, 0, sizeof(struct route));
-
-		if (inp->inp_faddr.s_addr == INADDR_ANY)
-			return (NULL);
-		ro->ro_dst.sa_family = AF_INET;
-		ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
-		satosin(&ro->ro_dst)->sin_addr = inp->inp_faddr;
-		ro->ro_tableid = inp->inp_rtableid;
 		ro->ro_rt = rtalloc_mpath(&ro->ro_dst,
 		    &inp->inp_laddr.s_addr, ro->ro_tableid);
 	}
diff --git a/sys/netinet6/in6.h b/sys/netinet6/in6.h
index 909166c7ac9..771f26c9cbb 100644
--- a/sys/netinet6/in6.h
+++ b/sys/netinet6/in6.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in6.h,v 1.113 2024/01/31 14:56:43 bluhm Exp $	*/
+/*	$OpenBSD: in6.h,v 1.114 2024/02/07 23:40:40 bluhm Exp $	*/
 /*	$KAME: in6.h,v 1.83 2001/03/29 02:55:07 jinmei Exp $	*/
 
 /*
@@ -428,6 +428,8 @@ int	in6_mask2len(struct in6_addr *, u_char *);
 int	in6_nam2sin6(const struct mbuf *, struct sockaddr_in6 **);
 int	in6_sa2sin6(struct sockaddr *, struct sockaddr_in6 **);
 
+void	route6_cache(struct route_in6 *, const struct in6_addr *, u_int);
+
 struct ip6_pktopts;
 struct ip6_moptions;
 
diff --git a/sys/netinet6/in6_pcb.c b/sys/netinet6/in6_pcb.c
index d447beb8329..0be0c4587d0 100644
--- a/sys/netinet6/in6_pcb.c
+++ b/sys/netinet6/in6_pcb.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in6_pcb.c,v 1.134 2024/01/31 12:27:57 bluhm Exp $	*/
+/*	$OpenBSD: in6_pcb.c,v 1.135 2024/02/07 23:40:40 bluhm Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -566,24 +566,10 @@ in6_pcbrtentry(struct inpcb *inp)
 {
 	struct route_in6 *ro = &inp->inp_route6;
 
-	/* check if route is still valid */
-	if (!rtisvalid(ro->ro_rt)) {
-		rtfree(ro->ro_rt);
-		ro->ro_rt = NULL;
-	}
-
-	/*
-	 * No route yet, so try to acquire one.
-	 */
+	if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
+		return (NULL);
+	route6_cache(ro, &inp->inp_faddr6, inp->inp_rtableid);
 	if (ro->ro_rt == NULL) {
-		memset(ro, 0, sizeof(struct route_in6));
-
-		if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
-			return (NULL);
-		ro->ro_dst.sin6_family = AF_INET6;
-		ro->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
-		ro->ro_dst.sin6_addr = inp->inp_faddr6;
-		ro->ro_tableid = inp->inp_rtableid;
 		ro->ro_rt = rtalloc_mpath(sin6tosa(&ro->ro_dst),
 		    &inp->inp_laddr6.s6_addr32[0], ro->ro_tableid);
 	}
diff --git a/sys/netinet6/in6_src.c b/sys/netinet6/in6_src.c
index 2c989ec154c..78205a08d83 100644
--- a/sys/netinet6/in6_src.c
+++ b/sys/netinet6/in6_src.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in6_src.c,v 1.91 2024/01/09 19:57:01 bluhm Exp $	*/
+/*	$OpenBSD: in6_src.c,v 1.92 2024/02/07 23:40:40 bluhm Exp $	*/
 /*	$KAME: in6_src.c,v 1.36 2001/02/06 04:08:17 itojun Exp $	*/
 
 /*
@@ -82,7 +82,7 @@
 #include <netinet6/ip6_var.h>
 #include <netinet6/nd6.h>
 
-int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *,
+int in6_selectif(const struct in6_addr *, struct ip6_pktopts *,
     struct ip6_moptions *, struct route_in6 *, struct ifnet **, u_int);
 
 /*
@@ -118,7 +118,7 @@ in6_pcbselsrc(const struct in6_addr **in6src, struct sockaddr_in6 *dstsock,
 		struct sockaddr_in6 sa6;
 
 		/* get the outgoing interface */
-		error = in6_selectif(dstsock, opts, mopts, ro, &ifp, rtableid);
+		error = in6_selectif(dst, opts, mopts, ro, &ifp, rtableid);
 		if (error)
 			return (error);
 
@@ -179,22 +179,8 @@ in6_pcbselsrc(const struct in6_addr **in6src, struct sockaddr_in6 *dstsock,
 	 * If route is known or can be allocated now,
 	 * our src addr is taken from the i/f, else punt.
 	 */
-	if (!rtisvalid(ro->ro_rt) || (ro->ro_tableid != rtableid) ||
-	    !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, dst)) {
-		rtfree(ro->ro_rt);
-		ro->ro_rt = NULL;
-	}
+	route6_cache(ro, dst, rtableid);
 	if (ro->ro_rt == NULL) {
-		struct sockaddr_in6 *sa6;
-
-		/* No route yet, so try to acquire one */
-		bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
-		ro->ro_tableid = rtableid;
-		sa6 = &ro->ro_dst;
-		sa6->sin6_family = AF_INET6;
-		sa6->sin6_len = sizeof(struct sockaddr_in6);
-		sa6->sin6_addr = *dst;
-		sa6->sin6_scope_id = dstsock->sin6_scope_id;
 		ro->ro_rt = rtalloc(sin6tosa(&ro->ro_dst),
 		    RT_RESOLVE, ro->ro_tableid);
 	}
@@ -312,35 +298,17 @@ in6_selectsrc(const struct in6_addr **in6src, struct sockaddr_in6 *dstsock,
 }
 
 struct rtentry *
-in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
+in6_selectroute(const struct in6_addr *dst, struct ip6_pktopts *opts,
     struct route_in6 *ro, unsigned int rtableid)
 {
-	struct in6_addr *dst;
-
-	dst = &dstsock->sin6_addr;
-
 	/*
 	 * Use a cached route if it exists and is valid, else try to allocate
 	 * a new one.
 	 */
 	if (ro) {
-		if (rtisvalid(ro->ro_rt))
-			KASSERT(sin6tosa(&ro->ro_dst)->sa_family == AF_INET6);
-		if (!rtisvalid(ro->ro_rt) ||
-		    !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, dst)) {
-			rtfree(ro->ro_rt);
-			ro->ro_rt = NULL;
-		}
+		route6_cache(ro, dst, rtableid);
 		if (ro->ro_rt == NULL) {
-			struct sockaddr_in6 *sa6;
-
 			/* No route yet, so try to acquire one */
-			bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
-			ro->ro_tableid = rtableid;
-			sa6 = &ro->ro_dst;
-			*sa6 = *dstsock;
-			sa6->sin6_scope_id = 0;
-			ro->ro_tableid = rtableid;
 			ro->ro_rt = rtalloc_mpath(sin6tosa(&ro->ro_dst),
 			    NULL, ro->ro_tableid);
 		}
@@ -369,7 +337,7 @@ in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
 }
 
 int
-in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
+in6_selectif(const struct in6_addr *dst, struct ip6_pktopts *opts,
     struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp,
     u_int rtableid)
 {
@@ -387,11 +355,11 @@ in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
 	 * If the destination address is a multicast address and the outgoing
 	 * interface for the address is specified by the caller, use it.
 	 */
-	if (IN6_IS_ADDR_MULTICAST(&dstsock->sin6_addr) &&
+	if (IN6_IS_ADDR_MULTICAST(dst) &&
 	    mopts != NULL && (*retifp = if_get(mopts->im6o_ifidx)) != NULL)
 	    	return (0);
 
-	rt = in6_selectroute(dstsock, opts, ro, rtableid);
+	rt = in6_selectroute(dst, opts, ro, rtableid);
 	if (rt == NULL)
 		return (EHOSTUNREACH);
 
diff --git a/sys/netinet6/ip6_forward.c b/sys/netinet6/ip6_forward.c
index 7de1e0ec701..54b7615f517 100644
--- a/sys/netinet6/ip6_forward.c
+++ b/sys/netinet6/ip6_forward.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip6_forward.c,v 1.112 2023/07/07 08:05:02 bluhm Exp $	*/
+/*	$OpenBSD: ip6_forward.c,v 1.113 2024/02/07 23:40:40 bluhm Exp $	*/
 /*	$KAME: ip6_forward.c,v 1.75 2001/06/29 12:42:13 jinmei Exp $	*/
 
 /*
@@ -85,7 +85,7 @@ void
 ip6_forward(struct mbuf *m, struct rtentry *rt, int srcrt)
 {
 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
-	struct sockaddr_in6 *sin6;
+	struct sockaddr *dst;
 	struct route_in6 ro;
 	struct ifnet *ifp = NULL;
 	int error = 0, type = 0, code = 0, destmtu = 0;
@@ -165,15 +165,12 @@ reroute:
 	}
 #endif /* IPSEC */
 
-	memset(&ro, 0, sizeof(ro));
-	sin6 = &ro.ro_dst;
-	sin6->sin6_family = AF_INET6;
-	sin6->sin6_len = sizeof(*sin6);
-	sin6->sin6_addr = ip6->ip6_dst;
-
+	ro.ro_rt = NULL;
+	route6_cache(&ro, &ip6->ip6_dst, m->m_pkthdr.ph_rtableid);
+	dst = sin6tosa(&ro.ro_dst);
 	if (!rtisvalid(rt)) {
 		rtfree(rt);
-		rt = rtalloc_mpath(sin6tosa(sin6), &ip6->ip6_src.s6_addr32[0],
+		rt = rtalloc_mpath(dst, &ip6->ip6_src.s6_addr32[0],
 		    m->m_pkthdr.ph_rtableid);
 		if (rt == NULL) {
 			ip6stat_inc(ip6s_noroute);
@@ -185,6 +182,7 @@ reroute:
 			goto out;
 		}
 	}
+	ro.ro_rt = rt;
 
 	/*
 	 * Scope check: if a packet can't be delivered to its destination
@@ -226,8 +224,6 @@ reroute:
 	 */
 	if (tdb != NULL) {
 		/* Callee frees mbuf */
-		ro.ro_rt = rt;
-		ro.ro_tableid = m->m_pkthdr.ph_rtableid;
 		error = ip6_output_ipsec_send(tdb, m, &ro, 0, 1);
 		rt = ro.ro_rt;
 		if (error)
@@ -237,7 +233,7 @@ reroute:
 #endif /* IPSEC */
 
 	if (rt->rt_flags & RTF_GATEWAY)
-		sin6 = satosin6(rt->rt_gateway);
+		dst = rt->rt_gateway;
 
 	/*
 	 * If we are to forward the packet using the same interface
@@ -319,7 +315,7 @@ reroute:
 	}
 #endif
 
-	error = if_output_tso(ifp, &m, sin6tosa(sin6), rt, ifp->if_mtu);
+	error = if_output_tso(ifp, &m, dst, rt, ifp->if_mtu);
 	if (error)
 		ip6stat_inc(ip6s_cantforward);
 	else if (m == NULL)
diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
index f3da1972a94..3efd26129cb 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip6_output.c,v 1.284 2024/01/31 12:27:57 bluhm Exp $	*/
+/*	$OpenBSD: ip6_output.c,v 1.285 2024/02/07 23:40:40 bluhm Exp $	*/
 /*	$KAME: ip6_output.c,v 1.172 2001/03/25 09:55:56 itojun Exp $	*/
 
 /*
@@ -169,7 +169,7 @@ ip6_output(struct mbuf *m, struct ip6_pktopts *opt, struct route_in6 *ro,
 	int hlen, tlen;
 	struct route_in6 ip6route;
 	struct rtentry *rt = NULL;
-	struct sockaddr_in6 *dst, dstsock;
+	struct sockaddr_in6 *dst;
 	int error = 0;
 	u_long mtu;
 	int dontfrag;
@@ -442,13 +442,7 @@ reroute:
 	}
 #endif /* IPSEC */
 
-	bzero(&dstsock, sizeof(dstsock));
-	dstsock.sin6_family = AF_INET6;
-	dstsock.sin6_addr = ip6->ip6_dst;
-	dstsock.sin6_len = sizeof(dstsock);
-	ro->ro_tableid = m->m_pkthdr.ph_rtableid;
-
-	if (IN6_IS_ADDR_MULTICAST(&dstsock.sin6_addr)) {
+	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 		struct in6_pktinfo *pi = NULL;
 
 		/*
@@ -463,7 +457,8 @@ reroute:
 	}
 
 	if (ifp == NULL) {
-		rt = in6_selectroute(&dstsock, opt, ro, ro->ro_tableid);
+		rt = in6_selectroute(&ip6->ip6_dst, opt, ro,
+		    m->m_pkthdr.ph_rtableid);
 		if (rt == NULL) {
 			ip6stat_inc(ip6s_noroute);
 			error = EHOSTUNREACH;
@@ -485,7 +480,7 @@ reroute:
 			goto bad;
 		}
 	} else {
-		*dst = dstsock;
+		route6_cache(ro, &ip6->ip6_dst, m->m_pkthdr.ph_rtableid);
 	}
 
 	if (rt && (rt->rt_flags & RTF_GATEWAY) &&
diff --git a/sys/netinet6/ip6_var.h b/sys/netinet6/ip6_var.h
index 06d6ce7572f..f23287b6f28 100644
--- a/sys/netinet6/ip6_var.h
+++ b/sys/netinet6/ip6_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip6_var.h,v 1.111 2024/02/05 23:16:39 bluhm Exp $	*/
+/*	$OpenBSD: ip6_var.h,v 1.112 2024/02/07 23:40:40 bluhm Exp $	*/
 /*	$KAME: ip6_var.h,v 1.33 2000/06/11 14:59:20 jinmei Exp $	*/
 
 /*
@@ -369,7 +369,7 @@ int	in6_pcbselsrc(const struct in6_addr **, struct sockaddr_in6 *,
 	    struct inpcb *, struct ip6_pktopts *);
 int	in6_selectsrc(const struct in6_addr **, struct sockaddr_in6 *,
 	    struct ip6_moptions *, unsigned int);
-struct rtentry *in6_selectroute(struct sockaddr_in6 *, struct ip6_pktopts *,
+struct rtentry *in6_selectroute(const struct in6_addr *, struct ip6_pktopts *,
 	    struct route_in6 *, unsigned int rtableid);
 
 u_int32_t ip6_randomflowlabel(void);