ipv6: add ipv6_fragment hook in ipv6_stub

Add ipv6_fragment to ipv6_stub to avoid calling netfilter when
access ip6_fragment.
Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ipv6_stubs.h

@@ -63,6 +63,9 @@ struct ipv6_stub {
 			       int encap_type);
 #endif
 	struct neigh_table *nd_tbl;
+
+	int (*ipv6_fragment)(struct net *net, struct sock *sk, struct sk_buff *skb,
+			     int (*output)(struct net *, struct sock *, struct sk_buff *));
 };
 extern const struct ipv6_stub *ipv6_stub __read_mostly;
 

net/ipv6/addrconf_core.c

@@ -191,6 +191,13 @@ static int eafnosupport_ip6_del_rt(struct net *net, struct fib6_info *rt,
 	return -EAFNOSUPPORT;
 }
 
+static int eafnosupport_ipv6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
+				      int (*output)(struct net *, struct sock *, struct sk_buff *))
+{
+	kfree_skb(skb);
+	return -EAFNOSUPPORT;
+}
+
 const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
 	.ipv6_dst_lookup_flow = eafnosupport_ipv6_dst_lookup_flow,
 	.ipv6_route_input  = eafnosupport_ipv6_route_input,
@@ -201,6 +208,7 @@ const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
 	.ip6_mtu_from_fib6 = eafnosupport_ip6_mtu_from_fib6,
 	.fib6_nh_init	   = eafnosupport_fib6_nh_init,
 	.ip6_del_rt	   = eafnosupport_ip6_del_rt,
+	.ipv6_fragment	   = eafnosupport_ipv6_fragment,
 };
 EXPORT_SYMBOL_GPL(ipv6_stub);
 

net/ipv6/af_inet6.c

@@ -1027,6 +1027,7 @@ static const struct ipv6_stub ipv6_stub_impl = {
 	.xfrm6_rcv_encap = xfrm6_rcv_encap,
 #endif
 	.nd_tbl	= &nd_tbl,
+	.ipv6_fragment = ip6_fragment,
 };
 
 static const struct ipv6_bpf_stub ipv6_bpf_stub_impl = {