From: Alexander Bluhm Subject: route cache and mpath To: tech@openbsd.org Date: Tue, 26 Mar 2024 20:25:37 +0100 Hi, I would like to recommit the route_mpath() diff that was backed out before 7.5 release. An additional rtisvalid() check has caused problems when the interface link was not up. I just removed that and now the diff should not change behavior. 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. ok? bluhm Index: net/route.c =================================================================== RCS file: /data/mirror/openbsd/cvs/src/sys/net/route.c,v diff -u -p -r1.435 route.c --- net/route.c 29 Feb 2024 12:01:59 -0000 1.435 +++ net/route.c 26 Mar 2024 19:17:12 -0000 @@ -239,6 +239,24 @@ route_cache(struct route *ro, const stru 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, @@ -276,6 +294,20 @@ route6_cache(struct route *ro, const str ro->ro_srcin6 = *src; 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 Index: net/route.h =================================================================== RCS file: /data/mirror/openbsd/cvs/src/sys/net/route.h,v diff -u -p -r1.209 route.h --- net/route.h 29 Feb 2024 12:01:59 -0000 1.209 +++ net/route.h 26 Mar 2024 19:17:12 -0000 @@ -465,7 +465,11 @@ 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); Index: netinet/in_pcb.c =================================================================== RCS file: /data/mirror/openbsd/cvs/src/sys/netinet/in_pcb.c,v diff -u -p -r1.298 in_pcb.c --- netinet/in_pcb.c 22 Mar 2024 21:48:38 -0000 1.298 +++ netinet/in_pcb.c 26 Mar 2024 19:17:12 -0000 @@ -904,23 +904,15 @@ in_pcblookup_local_lock(struct inpcbtabl 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, stru 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, stru * 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, stru * - 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; Index: netinet6/in6_pcb.c =================================================================== RCS file: /data/mirror/openbsd/cvs/src/sys/netinet6/in6_pcb.c,v diff -u -p -r1.142 in6_pcb.c --- netinet6/in6_pcb.c 22 Mar 2024 18:05:01 -0000 1.142 +++ netinet6/in6_pcb.c 26 Mar 2024 19:17:12 -0000 @@ -561,16 +561,10 @@ in6_pcbnotify(struct inpcbtable *table, 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 * Index: netinet6/in6_src.c =================================================================== RCS file: /data/mirror/openbsd/cvs/src/sys/netinet6/in6_src.c,v diff -u -p -r1.97 in6_src.c --- netinet6/in6_src.c 29 Feb 2024 12:01:59 -0000 1.97 +++ netinet6/in6_src.c 26 Mar 2024 19:17:12 -0000 @@ -95,7 +95,7 @@ in6_pcbselsrc(const struct in6_addr **in 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 **in 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 **in * 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 **in * 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 **in * - 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 *d * 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 *d */ 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_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, * 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); }