2 * (C) 2007 by Sebastian Claßen <sebastian.classen@freenet.ag>
3 * (C) 2007-2010 by Jan Engelhardt <jengelh@medozas.de>
5 * Extracted from xt_TEE.c
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 or later, as
9 * published by the Free Software Foundation.
11 #include <linux/module.h>
12 #include <linux/percpu.h>
13 #include <linux/skbuff.h>
14 #include <linux/netfilter.h>
16 #include <net/ip6_route.h>
17 #include <net/netfilter/ipv6/nf_dup_ipv6.h>
18 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
19 #include <net/netfilter/nf_conntrack.h>
22 static struct net *pick_net(struct sk_buff *skb)
25 const struct dst_entry *dst;
28 return dev_net(skb->dev);
30 if (dst != NULL && dst->dev != NULL)
31 return dev_net(dst->dev);
36 static bool nf_dup_ipv6_route(struct sk_buff *skb, const struct in6_addr *gw,
39 const struct ipv6hdr *iph = ipv6_hdr(skb);
40 struct net *net = pick_net(skb);
41 struct dst_entry *dst;
44 memset(&fl6, 0, sizeof(fl6));
49 fl6.flowlabel = (__force __be32)(((iph->flow_lbl[0] & 0xF) << 16) |
50 (iph->flow_lbl[1] << 8) | iph->flow_lbl[2]);
51 dst = ip6_route_output(net, NULL, &fl6);
57 skb_dst_set(skb, dst);
59 skb->protocol = htons(ETH_P_IPV6);
64 void nf_dup_ipv6(struct sk_buff *skb, unsigned int hooknum,
65 const struct in6_addr *gw, int oif)
67 if (this_cpu_read(nf_skb_duplicated))
69 skb = pskb_copy(skb, GFP_ATOMIC);
73 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
74 nf_conntrack_put(skb->nfct);
75 skb->nfct = &nf_ct_untracked_get()->ct_general;
76 skb->nfctinfo = IP_CT_NEW;
77 nf_conntrack_get(skb->nfct);
79 if (hooknum == NF_INET_PRE_ROUTING ||
80 hooknum == NF_INET_LOCAL_IN) {
81 struct ipv6hdr *iph = ipv6_hdr(skb);
84 if (nf_dup_ipv6_route(skb, gw, oif)) {
85 __this_cpu_write(nf_skb_duplicated, true);
87 __this_cpu_write(nf_skb_duplicated, false);
92 EXPORT_SYMBOL_GPL(nf_dup_ipv6);
94 MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@freenet.ag>");
95 MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
96 MODULE_DESCRIPTION("nf_dup_ipv6: IPv6 packet duplication");
97 MODULE_LICENSE("GPL");