netfilter: conntrack: remove l3->l4 mapping information

l4 protocols are demuxed by l3num, l4num pair.

However, almost all l4 trackers are l3 agnostic.

Only exceptions are:
 - gre, icmp (ipv4 only)
 - icmpv6 (ipv6 only)

This commit gets rid of the l3 mapping, l4 trackers can now be looked up
by their IPPROTO_XXX value alone, which gets rid of the additional l3
indirection.

For icmp, ipcmp6 and gre, add a check on state->pf and
return -NF_ACCEPT in case we're asked to track e.g. icmpv6-in-ipv4,
this seems more fitting than using the generic tracker.

Additionally we can kill the 2nd l4proto definitions that were needed
for v4/v6 split -- they are now the same so we can use single l4proto
struct for each protocol, rather than two.

The EXPORT_SYMBOLs can be removed as all these object files are
part of nf_conntrack with no external references.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 6 insertions, 8 deletions

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index f8c74f31aa36..099a450e26be 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -135,8 +135,7 @@ static int ctnetlink_dump_tuples(struct sk_buff *skb,
 	ret = ctnetlink_dump_tuples_ip(skb, tuple);
 
 	if (ret >= 0) {
-		l4proto = __nf_ct_l4proto_find(tuple->src.l3num,
-					       tuple->dst.protonum);
+		l4proto = __nf_ct_l4proto_find(tuple->dst.protonum);
 		ret = ctnetlink_dump_tuples_proto(skb, tuple, l4proto);
 	}
 	rcu_read_unlock();
@@ -184,7 +183,7 @@ static int ctnetlink_dump_protoinfo(struct sk_buff *skb, struct nf_conn *ct)
 	struct nlattr *nest_proto;
 	int ret;
 
-	l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
+	l4proto = __nf_ct_l4proto_find(nf_ct_protonum(ct));
 	if (!l4proto->to_nlattr)
 		return 0;
 
@@ -592,7 +591,7 @@ static size_t ctnetlink_proto_size(const struct nf_conn *ct)
 	len = nla_policy_len(cta_ip_nla_policy, CTA_IP_MAX + 1);
 	len *= 3u; /* ORIG, REPLY, MASTER */
 
-	l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
+	l4proto = __nf_ct_l4proto_find(nf_ct_protonum(ct));
 	len += l4proto->nlattr_size;
 	if (l4proto->nlattr_tuple_size) {
 		len4 = l4proto->nlattr_tuple_size();
@@ -1054,7 +1053,7 @@ static int ctnetlink_parse_tuple_proto(struct nlattr *attr,
 	tuple->dst.protonum = nla_get_u8(tb[CTA_PROTO_NUM]);
 
 	rcu_read_lock();
-	l4proto = __nf_ct_l4proto_find(tuple->src.l3num, tuple->dst.protonum);
+	l4proto = __nf_ct_l4proto_find(tuple->dst.protonum);
 
 	if (likely(l4proto->nlattr_to_tuple)) {
 		ret = nla_validate_nested(attr, CTA_PROTO_MAX,
@@ -1702,7 +1701,7 @@ static int ctnetlink_change_protoinfo(struct nf_conn *ct,
 		return err;
 
 	rcu_read_lock();
-	l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
+	l4proto = __nf_ct_l4proto_find(nf_ct_protonum(ct));
 	if (l4proto->from_nlattr)
 		err = l4proto->from_nlattr(tb, ct);
 	rcu_read_unlock();
@@ -2662,8 +2661,7 @@ static int ctnetlink_exp_dump_mask(struct sk_buff *skb,
 	rcu_read_lock();
 	ret = ctnetlink_dump_tuples_ip(skb, &m);
 	if (ret >= 0) {
-		l4proto = __nf_ct_l4proto_find(tuple->src.l3num,
-					       tuple->dst.protonum);
+		l4proto = __nf_ct_l4proto_find(tuple->dst.protonum);
 	ret = ctnetlink_dump_tuples_proto(skb, &m, l4proto);
 	}
 	rcu_read_unlock();