Hello,
thanks for detailed explanation.
> + else {
> + struct ifnet *destifp;
> +
> + destifp = if_get(rt->rt_ifidx);
> + if (destifp != NULL)
> + destmtu = destifp->if_mtu;
> + if_put(destifp);
> + }
your code potentially leaves destmtu set to 0 in case we deal with invalid
ipforward_rt. I wonder how icmp_error() we are going to call further below
(at line 1544 in the old code) is going to deal with it. May be we
should just give up on sending ICMP_UNREACH message in this case.
find my small improvement to your patch further below.
regards
sasha
--------8<---------------8<---------------8<------------------8<--------
Warning: Permanently added 'anoncvs.spacehopper.org' (ECDSA) to the list of
known hosts.
Index: ip_input.c
===================================================================
RCS file: /cvs/src/sys/netinet/ip_input.c,v
retrieving revision 1.261
diff -u -p -r1.261 ip_input.c
--- ip_input.c 14 Nov 2015 15:40:40 -0000 1.261
+++ ip_input.c 20 Nov 2015 15:48:47 -0000
@@ -1516,11 +1516,24 @@ ip_forward(struct mbuf *m, struct ifnet
if (rt->rt_rmx.rmx_mtu)
destmtu = rt->rt_rmx.rmx_mtu;
- else
- destmtu = ipforward_rt.ro_rt->rt_ifp->if_mtu;
+ else {
+ struct ifnet *destifp;
+
+ destifp = if_get(rt->rt_ifidx);
+ if (destifp != NULL)
+ destmtu = destifp->if_mtu;
+ if_put(destifp);
+ }
}
#endif /*IPSEC*/
ipstat.ips_cantfrag++;
+
+ /*
+ * route to destniation no longer exists, we should revert code
+ * back to host unreachable.
+ */
+ if (destmtu == 0)
+ code = ICMP_UNREACH_HOST;
break;
case EACCES:
