Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

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).
This commit is contained in:
kim 2020-04-13 14:04:27 +00:00
parent 5b81bbd6c0
commit c729dd4278
1 changed files with 23 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
sys/netinet6/nd6_rtr.c
View File

@ -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 *newdr)
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,