On the train back from n2k16 I found the real cause of the hang reported
by Dimitris Papastamos [0] and exposed by our recent
changes to the routing table.
When an interface is removed/detached the kernel delete all the
corresponding route entries. At this moment the interface is
DOWN and the corresponding route as well. So the priority check
should consider that.
Without the diff attached or the workaround to stop iterating when
an error occurs, the kernel would loop forever since it can't remove
the RTF_BROADCAST entry.
[0] https://marc.info/?l=openbsd-bugs&m=146909621511954&w=2
ok?
Index: net/route.c
===================================================================
RCS file: /cvs/src/sys/net/route.c,v
retrieving revision 1.313
diff -u -p -r1.313 route.c
--- net/route.c 22 Jul 2016 11:03:30 -0000 1.313
+++ net/route.c 8 Aug 2016 09:33:15 -0000
@@ -873,7 +873,7 @@ rtrequest_delete(struct rt_addrinfo *inf
* kernel.
*/
if ((rt->rt_flags & (RTF_LOCAL|RTF_BROADCAST)) &&
- prio != RTP_LOCAL) {
+ (prio & RTP_MASK) != RTP_LOCAL) {
rtfree(rt);
return (EINVAL);
}
