lib: unset ZEBRA_IFA_PEER if no dst addr present (BZ#801)
On OpenBSD, carp interfaces claim to be PtP interfaces with a 0.0.0.0/0
peer address. We process those in zebra and try to send them to
clients, at which point they get encoded as all-0. The client code,
however, decodes that to a NULL pointer instead of 0.0.0.0. This later
turns into a SEGV when CONNECTED_PREFIX sees that ZEBRA_IFA_PEER is set
and tries to access the peer prefix.
This is a band-aid fix for stable/0.99.23, a long-term solution needs
some conceptual improvements on the entire thing.
(The usefulness of a PtP-to-0.0.0.0/0 is a separate question; at this
point dropping the peer prefix seems the least intrusive solution.)
Reported-by: Laurent Lavaud <laurent.lavaud@ladtech.fr>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/lib/zclient.c b/lib/zclient.c
index 20188f6..3b5477e 100644
--- a/lib/zclient.c
+++ b/lib/zclient.c
@@ -805,6 +805,16 @@
ifc->flags = ifc_flags;
if (ifc->destination)
ifc->destination->prefixlen = ifc->address->prefixlen;
+ else if (CHECK_FLAG(ifc->flags, ZEBRA_IFA_PEER))
+ {
+ /* carp interfaces on OpenBSD with 0.0.0.0/0 as "peer" */
+ char buf[BUFSIZ];
+ prefix2str (ifc->address, buf, sizeof(buf));
+ zlog_warn("warning: interface %s address %s "
+ "with peer flag set, but no peer address!",
+ ifp->name, buf);
+ UNSET_FLAG(ifc->flags, ZEBRA_IFA_PEER);
+ }
}
}
else