1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * (C) 2007 by Sebastian Claßen <sebastian.classen@freenet.ag>
4 * (C) 2007-2010 by Jan Engelhardt <jengelh@medozas.de>
6 * Extracted from xt_TEE.c
8 #include <linux/module.h>
9 #include <linux/percpu.h>
10 #include <linux/skbuff.h>
11 #include <linux/netfilter.h>
13 #include <net/ip6_route.h>
14 #include <net/netfilter/ipv6/nf_dup_ipv6.h>
15 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
16 #include <net/netfilter/nf_conntrack.h>
19 static bool nf_dup_ipv6_route(struct net *net, struct sk_buff *skb,
20 const struct in6_addr *gw, int oif)
22 const struct ipv6hdr *iph = ipv6_hdr(skb);
23 struct dst_entry *dst;
26 memset(&fl6, 0, sizeof(fl6));
31 fl6.flowlabel = (__force __be32)(((iph->flow_lbl[0] & 0xF) << 16) |
32 (iph->flow_lbl[1] << 8) | iph->flow_lbl[2]);
33 fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH;
34 dst = ip6_route_output(net, NULL, &fl6);
40 skb_dst_set(skb, dst);
42 skb->protocol = htons(ETH_P_IPV6);
47 void nf_dup_ipv6(struct net *net, struct sk_buff *skb, unsigned int hooknum,
48 const struct in6_addr *gw, int oif)
50 if (this_cpu_read(nf_skb_duplicated))
52 skb = pskb_copy(skb, GFP_ATOMIC);
56 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
58 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
60 if (hooknum == NF_INET_PRE_ROUTING ||
61 hooknum == NF_INET_LOCAL_IN) {
62 struct ipv6hdr *iph = ipv6_hdr(skb);
65 if (nf_dup_ipv6_route(net, skb, gw, oif)) {
66 __this_cpu_write(nf_skb_duplicated, true);
67 ip6_local_out(net, skb->sk, skb);
68 __this_cpu_write(nf_skb_duplicated, false);
73 EXPORT_SYMBOL_GPL(nf_dup_ipv6);
75 MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@freenet.ag>");
76 MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
77 MODULE_DESCRIPTION("nf_dup_ipv6: IPv6 packet duplication");
78 MODULE_LICENSE("GPL");