Combine route_cache() and rtalloc_mpath() in new route_mpath().

Fill and check the cache and call rtalloc_mpath() together.  Then
the caller of route_mpath() does not have to care about the uint32_t
*src pointer and just pass struct in_addr.  All the conversions are
done inside the functions.

A previous version of this diff was backed out.  There was an
additional rtisvalid() in rtalloc_mpath() that prevented packet
output via interfaces that were not up.  Now the route in the cache
has to be valid, but after new lookup, rtalloc_mpath() may return
invalid routes.  This generates less errors in userland an preserves
existing behavior.

OK sashan@

diff --git a/sys/net/route.c b/sys/net/route.c
index 9dadb5a..028199b 100644 (file)
--- a/sys/net/route.c
+++ b/sys/net/route.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: route.c,v 1.435 2024/02/29 12:01:59 naddy Exp $       */
+/*     $OpenBSD: route.c,v 1.436 2024/03/31 15:53:12 bluhm Exp $       */
 /*     $NetBSD: route.c,v 1.14 1996/02/13 22:00:46 christos Exp $      */
 
 /*
@@ -239,6 +239,24 @@ route_cache(struct route *ro, const struct in_addr *dst,
        return (ESRCH);
 }
 
+/*
+ * Check cache for route, else allocate a new one, potentially using multipath
+ * to select the peer.  Update cache and return valid route or NULL.
+ */
+struct rtentry *
+route_mpath(struct route *ro, const struct in_addr *dst,
+    const struct in_addr *src, u_int rtableid)
+{
+       if (route_cache(ro, dst, src, rtableid)) {
+               uint32_t *s = NULL;
+
+               if (ro->ro_srcin.s_addr != INADDR_ANY)
+                       s = &ro->ro_srcin.s_addr;
+               ro->ro_rt = rtalloc_mpath(&ro->ro_dstsa, s, ro->ro_tableid);
+       }
+       return (ro->ro_rt);
+}
+
 #ifdef INET6
 int
 route6_cache(struct route *ro, const struct in6_addr *dst,
@@ -277,6 +295,20 @@ route6_cache(struct route *ro, const struct in6_addr *dst,
 
        return (ESRCH);
 }
+
+struct rtentry *
+route6_mpath(struct route *ro, const struct in6_addr *dst,
+    const struct in6_addr *src, u_int rtableid)
+{
+       if (route6_cache(ro, dst, src, rtableid)) {
+               uint32_t *s = NULL;
+
+               if (!IN6_IS_ADDR_UNSPECIFIED(&ro->ro_srcin6))
+                       s = &ro->ro_srcin6.s6_addr32[0];
+               ro->ro_rt = rtalloc_mpath(&ro->ro_dstsa, s, ro->ro_tableid);
+       }
+       return (ro->ro_rt);
+}
 #endif
 
 /*

diff --git a/sys/net/route.h b/sys/net/route.h
index c05a70d..a301193 100644 (file)
--- a/sys/net/route.h
+++ b/sys/net/route.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: route.h,v 1.209 2024/02/29 12:01:59 naddy Exp $       */
+/*     $OpenBSD: route.h,v 1.210 2024/03/31 15:53:12 bluhm Exp $       */
 /*     $NetBSD: route.h,v 1.9 1996/02/13 22:00:49 christos Exp $       */
 
 /*
@@ -465,8 +465,12 @@ struct bfd_config;
 void    route_init(void);
 int     route_cache(struct route *, const struct in_addr *,
            const struct in_addr *, u_int);
+struct rtentry *route_mpath(struct route *, const struct in_addr *,
+           const struct in_addr *, u_int);
 int     route6_cache(struct route *, const struct in6_addr *,
            const struct in6_addr *, u_int);
+struct rtentry *route6_mpath(struct route *, const struct in6_addr *,
+           const struct in6_addr *, u_int);
 void    rtm_ifchg(struct ifnet *);
 void    rtm_ifannounce(struct ifnet *, int);
 void    rtm_bfd(struct bfd_config *);

diff --git a/sys/netinet/in_pcb.c b/sys/netinet/in_pcb.c
index 12c0b86..b937c78 100644 (file)
--- a/sys/netinet/in_pcb.c
+++ b/sys/netinet/in_pcb.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: in_pcb.c,v 1.298 2024/03/22 21:48:38 bluhm Exp $      */
+/*     $OpenBSD: in_pcb.c,v 1.299 2024/03/31 15:53:12 bluhm Exp $      */
 /*     $NetBSD: in_pcb.c,v 1.25 1996/02/13 23:41:53 christos Exp $     */
 
 /*
@@ -904,23 +904,15 @@ in_pcblookup_local_lock(struct inpcbtable *table, const void *laddrp,
 struct rtentry *
 in_pcbrtentry(struct inpcb *inp)
 {
-       struct route *ro;
-
 #ifdef INET6
        if (ISSET(inp->inp_flags, INP_IPV6))
                return in6_pcbrtentry(inp);
 #endif
 
-       ro = &inp->inp_route;
-
        if (inp->inp_faddr.s_addr == INADDR_ANY)
                return (NULL);
-       if (route_cache(ro, &inp->inp_faddr, &inp->inp_laddr,
-           inp->inp_rtableid)) {
-               ro->ro_rt = rtalloc_mpath(&ro->ro_dstsa,
-                   &inp->inp_laddr.s_addr, ro->ro_tableid);
-       }
-       return (ro->ro_rt);
+       return (route_mpath(&inp->inp_route, &inp->inp_faddr, &inp->inp_laddr,
+           inp->inp_rtableid));
 }
 
 /*
@@ -934,7 +926,7 @@ in_pcbselsrc(struct in_addr *insrc, struct sockaddr_in *sin,
     struct inpcb *inp)
 {
        struct ip_moptions *mopts = inp->inp_moptions;
-       struct route *ro = &inp->inp_route;
+       struct rtentry *rt;
        const struct in_addr *laddr = &inp->inp_laddr;
        u_int rtableid = inp->inp_rtableid;
        struct sockaddr *ip4_source = NULL;
@@ -979,17 +971,14 @@ in_pcbselsrc(struct in_addr *insrc, struct sockaddr_in *sin,
         * If route is known or can be allocated now,
         * our src addr is taken from the i/f, else punt.
         */
-       if (route_cache(ro, &sin->sin_addr, NULL, rtableid)) {
-               /* No route yet, so try to acquire one */
-               ro->ro_rt = rtalloc_mpath(&ro->ro_dstsa, NULL, ro->ro_tableid);
-       }
+       rt = route_mpath(&inp->inp_route, &sin->sin_addr, NULL, rtableid);
 
        /*
         * If we found a route, use the address
         * corresponding to the outgoing interface.
         */
-       if (ro->ro_rt != NULL)
-               ia = ifatoia(ro->ro_rt->rt_ifa);
+       if (rt != NULL)
+               ia = ifatoia(rt->rt_ifa);
 
        /*
         * Use preferred source address if :
@@ -997,8 +986,8 @@ in_pcbselsrc(struct in_addr *insrc, struct sockaddr_in *sin,
         * - preferred source address is set
         * - output interface is UP
         */
-       if (ro->ro_rt && !(ro->ro_rt->rt_flags & RTF_LLINFO) &&
-           !(ro->ro_rt->rt_flags & RTF_HOST)) {
+       if (rt != NULL && !(rt->rt_flags & RTF_LLINFO) &&
+           !(rt->rt_flags & RTF_HOST)) {
                ip4_source = rtable_getsource(rtableid, AF_INET);
                if (ip4_source != NULL) {
                        struct ifaddr *ifa;

diff --git a/sys/netinet6/in6_pcb.c b/sys/netinet6/in6_pcb.c
index 88b6e60..edace54 100644 (file)
--- a/sys/netinet6/in6_pcb.c
+++ b/sys/netinet6/in6_pcb.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: in6_pcb.c,v 1.142 2024/03/22 18:05:01 bluhm Exp $     */
+/*     $OpenBSD: in6_pcb.c,v 1.143 2024/03/31 15:53:12 bluhm Exp $     */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -561,16 +561,10 @@ in6_pcbnotify(struct inpcbtable *table, const struct sockaddr_in6 *dst,
 struct rtentry *
 in6_pcbrtentry(struct inpcb *inp)
 {
-       struct route *ro = &inp->inp_route;
-
        if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
                return (NULL);
-       if (route6_cache(ro, &inp->inp_faddr6, &inp->inp_laddr6,
-           inp->inp_rtableid)) {
-               ro->ro_rt = rtalloc_mpath(&ro->ro_dstsa,
-                   &inp->inp_laddr6.s6_addr32[0], ro->ro_tableid);
-       }
-       return (ro->ro_rt);
+       return (route6_mpath(&inp->inp_route, &inp->inp_faddr6,
+           &inp->inp_laddr6, inp->inp_rtableid));
 }
 
 struct inpcb *

diff --git a/sys/netinet6/in6_src.c b/sys/netinet6/in6_src.c
index 2ebfdb9..d6163d2 100644 (file)
--- a/sys/netinet6/in6_src.c
+++ b/sys/netinet6/in6_src.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: in6_src.c,v 1.97 2024/02/29 12:01:59 naddy Exp $      */
+/*     $OpenBSD: in6_src.c,v 1.98 2024/03/31 15:53:12 bluhm Exp $      */
 /*     $KAME: in6_src.c,v 1.36 2001/02/06 04:08:17 itojun Exp $        */
 
 /*
@@ -95,7 +95,7 @@ in6_pcbselsrc(const struct in6_addr **in6src, struct sockaddr_in6 *dstsock,
     struct inpcb *inp, struct ip6_pktopts *opts)
 {
        struct ip6_moptions *mopts = inp->inp_moptions6;
-       struct route *ro = &inp->inp_route;
+       struct rtentry *rt;
        const struct in6_addr *laddr = &inp->inp_laddr6;
        u_int rtableid = inp->inp_rtableid;
        struct ifnet *ifp = NULL;
@@ -118,7 +118,8 @@ in6_pcbselsrc(const struct in6_addr **in6src, struct sockaddr_in6 *dstsock,
                struct sockaddr_in6 sa6;
 
                /* get the outgoing interface */
-               error = in6_selectif(dst, opts, mopts, ro, &ifp, rtableid);
+               error = in6_selectif(dst, opts, mopts, &inp->inp_route, &ifp,
+                   rtableid);
                if (error)
                        return (error);
 
@@ -179,9 +180,7 @@ 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 (route6_cache(ro, dst, NULL, rtableid)) {
-               ro->ro_rt = rtalloc_mpath(&ro->ro_dstsa, NULL, ro->ro_tableid);
-       }
+       rt = route6_mpath(&inp->inp_route, dst, NULL, rtableid);
 
        /*
         * in_pcbconnect() checks out IFF_LOOPBACK to skip using
@@ -190,14 +189,14 @@ in6_pcbselsrc(const struct in6_addr **in6src, struct sockaddr_in6 *dstsock,
         * so doesn't check out IFF_LOOPBACK.
         */
 
-       if (ro->ro_rt) {
-               ifp = if_get(ro->ro_rt->rt_ifidx);
+       if (rt != NULL) {
+               ifp = if_get(rt->rt_ifidx);
                if (ifp != NULL) {
                        ia6 = in6_ifawithscope(ifp, dst, rtableid);
                        if_put(ifp);
                }
                if (ia6 == NULL) /* xxx scope error ?*/
-                       ia6 = ifatoia6(ro->ro_rt->rt_ifa);
+                       ia6 = ifatoia6(rt->rt_ifa);
        }
 
        /*
@@ -206,8 +205,8 @@ in6_pcbselsrc(const struct in6_addr **in6src, struct sockaddr_in6 *dstsock,
         * - preferred source address is set
         * - output interface is UP
         */
-       if (ro->ro_rt && !(ro->ro_rt->rt_flags & RTF_LLINFO) &&
-           !(ro->ro_rt->rt_flags & RTF_HOST)) {
+       if (rt != NULL && !(rt->rt_flags & RTF_LLINFO) &&
+           !(rt->rt_flags & RTF_HOST)) {
                ip6_source = rtable_getsource(rtableid, AF_INET6);
                if (ip6_source != NULL) {
                        struct ifaddr *ifa;
@@ -304,11 +303,9 @@ in6_selectroute(const struct in6_addr *dst, struct ip6_pktopts *opts,
         * a new one.
         */
        if (ro) {
-               if (route6_cache(ro, dst, NULL, rtableid)) {
-                       /* No route yet, so try to acquire one */
-                       ro->ro_rt = rtalloc_mpath(&ro->ro_dstsa, NULL,
-                           ro->ro_tableid);
-               }
+               struct rtentry *rt;
+
+               rt = route6_mpath(ro, dst, NULL, rtableid);
 
                /*
                 * Check if the outgoing interface conflicts with
@@ -319,15 +316,13 @@ in6_selectroute(const struct in6_addr *dst, struct ip6_pktopts *opts,
                 */
                if (opts && opts->ip6po_pktinfo &&
                    opts->ip6po_pktinfo->ipi6_ifindex) {
-                       if (ro->ro_rt != NULL &&
-                           !ISSET(ro->ro_rt->rt_flags, RTF_LOCAL) &&
-                           ro->ro_rt->rt_ifidx !=
-                           opts->ip6po_pktinfo->ipi6_ifindex) {
+                       if (rt != NULL && !ISSET(rt->rt_flags, RTF_LOCAL) &&
+                           rt->rt_ifidx != opts->ip6po_pktinfo->ipi6_ifindex) {
                                return (NULL);
                        }
                }
 
-               return (ro->ro_rt);
+               return (rt);
        }
 
        return (NULL);
@@ -338,7 +333,7 @@ in6_selectif(const struct in6_addr *dst, struct ip6_pktopts *opts,
     struct ip6_moptions *mopts, struct route *ro, struct ifnet **retifp,
     u_int rtableid)
 {
-       struct rtentry *rt = NULL;
+       struct rtentry *rt;
        struct in6_pktinfo *pi = NULL;
 
        /* If the caller specify the outgoing interface explicitly, use it. */
@@ -377,11 +372,10 @@ in6_selectif(const struct in6_addr *dst, struct ip6_pktopts *opts,
         * Although this may not be very harmful, it should still be confusing.
         * We thus reject the case here.
         */
-       if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE)))
+       if (ISSET(rt->rt_flags, RTF_REJECT | RTF_BLACKHOLE))
                return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
 
-       if (rt != NULL)
-               *retifp = if_get(rt->rt_ifidx);
+       *retifp = if_get(rt->rt_ifidx);
 
        return (0);
 }