Module Name: src Committed By: kim Date: Mon Apr 13 14:04:27 UTC 2020
Modified Files: src/sys/netinet6: nd6_rtr.c Log Message: Fix default route selection The primary issue was that in revision 1.79 a check was added in the nd6_defrouter_select() search loop to ignore the entry if RA processing is enabled on its interface. In practice this results in all entries being ignored. This fix reverses the condition, so that an entry is ignored when RA processing is NOT enabled on its interface. Further, the entry is only ignored for being selected as the default router. The currently installed router must be identified regardless of the (current) status of its interface, so that we can delete the route before installing a new one. I also added error logging when adding or deleting a route fails. This should help the administrator (or kernel developer) in noticing possible problems. Finally, if deleting a route fails, the corresponding default route entry no longer has its "installed" flag cleared, so that deletion will be retried. At a minimum, this will cause repeated messages about the failed deletion as opposed to only getting repeated messages about the installation of a new default route failing. Fixes PR kern/55091 and also PR bin/54997 as far as the behaviour observed with ndp(8). To generate a diff of this commit: cvs rdiff -u -r1.147 -r1.148 src/sys/netinet6/nd6_rtr.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
Modified files: Index: src/sys/netinet6/nd6_rtr.c diff -u src/sys/netinet6/nd6_rtr.c:1.147 src/sys/netinet6/nd6_rtr.c:1.148 --- src/sys/netinet6/nd6_rtr.c:1.147 Fri Dec 27 10:17:56 2019 +++ src/sys/netinet6/nd6_rtr.c Mon Apr 13 14:04:27 2020 @@ -1,4 +1,4 @@ -/* $NetBSD: nd6_rtr.c,v 1.147 2019/12/27 10:17:56 msaitoh Exp $ */ +/* $NetBSD: nd6_rtr.c,v 1.148 2020/04/13 14:04:27 kim Exp $ */ /* $KAME: nd6_rtr.c,v 1.95 2001/02/07 08:09:47 itojun Exp $ */ /* @@ -31,7 +31,7 @@ */ #include <sys/cdefs.h> -__KERNEL_RCSID(0, "$NetBSD: nd6_rtr.c,v 1.147 2019/12/27 10:17:56 msaitoh Exp $"); +__KERNEL_RCSID(0, "$NetBSD: nd6_rtr.c,v 1.148 2020/04/13 14:04:27 kim Exp $"); #ifdef _KERNEL_OPT #include "opt_net_mpsafe.h" @@ -487,6 +487,11 @@ defrouter_addreq(struct nd_defrouter *ne if (error == 0) { nd6_numroutes++; newdr->installed = 1; + } else { + char ip6buf[INET6_ADDRSTRLEN]; + log(LOG_ERR, "defrouter_addreq: " + "error %d adding default router %s on %s\n", + error, IN6_PRINT(ip6buf, &newdr->rtaddr), newdr->ifp->if_xname); } #ifndef NET_MPSAFE splx(s); @@ -596,10 +601,15 @@ defrouter_delreq(struct nd_defrouter *dr error = rtrequest_newmsg(RTM_DELETE, &def.sa, &gw.sa, &mask.sa, RTF_GATEWAY); - if (error == 0) + if (error == 0) { nd6_numroutes--; - - dr->installed = 0; + dr->installed = 0; + } else { + char ip6buf[INET6_ADDRSTRLEN]; + log(LOG_ERR, "defrouter_delreq: " + "error %d deleting default router %s on %s\n", + error, IN6_PRINT(ip6buf, &dr->rtaddr), dr->ifp->if_xname); + } } /* @@ -675,14 +685,6 @@ nd6_defrouter_select(void) * the ordering rule of the list described in defrtrlist_update(). */ ND_DEFROUTER_LIST_FOREACH(dr) { - ndi = ND_IFINFO(dr->ifp); - if (nd6_accepts_rtadv(ndi)) - continue; - - if (selected_dr == NULL && - nd6_is_llinfo_probreach(dr)) - selected_dr = dr; - if (dr->installed && !installed_dr) installed_dr = dr; else if (dr->installed && installed_dr) { @@ -690,6 +692,14 @@ nd6_defrouter_select(void) log(LOG_ERR, "nd6_defrouter_select: more than one router" " is installed\n"); } + + ndi = ND_IFINFO(dr->ifp); + if (!nd6_accepts_rtadv(ndi)) + continue; + + if (selected_dr == NULL && + nd6_is_llinfo_probreach(dr)) + selected_dr = dr; } /* * If none of the default routers was found to be reachable,