Commit 6114cc51 authored Nov 03, 2016 by Florian Westphal Committed by Pablo Neira Ayuso Nov 08, 2016

netfilter: conntrack: fix CT target for UNSPEC helpers



Thomas reports its not possible to attach the H.245 helper:

iptables -t raw -A PREROUTING -p udp -j CT --helper H.245
iptables: No chain/target/match by that name.
xt_CT: No such helper "H.245"

This is because H.245 registers as NFPROTO_UNSPEC, but the CT target
passes NFPROTO_IPV4/IPV6 to nf_conntrack_helper_try_module_get.

We should treat UNSPEC as wildcard and ignore the l3num instead.

Reported-by: Thomas Woerner <twoerner@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

parent fb9c9649

net/netfilter/nf_conntrack_helper.c

+8 −3

Original line number	Diff line number	Diff line
		@@ -138,9 +138,14 @@ __nf_conntrack_helper_find(const char *name, u16 l3num, u8 protonum)

		for (i = 0; i < nf_ct_helper_hsize; i++) {
		hlist_for_each_entry_rcu(h, &nf_ct_helper_hash[i], hnode) {
		if (!strcmp(h->name, name) &&
		h->tuple.src.l3num == l3num &&
		h->tuple.dst.protonum == protonum)
		if (strcmp(h->name, name))
		continue;

		if (h->tuple.src.l3num != NFPROTO_UNSPEC &&
		h->tuple.src.l3num != l3num)
		continue;

		if (h->tuple.dst.protonum == protonum)
		return h;
		}
		}