diff options
Diffstat (limited to 'net/ipv6/netfilter/nf_dup_ipv6.c')
| -rw-r--r-- | net/ipv6/netfilter/nf_dup_ipv6.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/nf_dup_ipv6.c b/net/ipv6/netfilter/nf_dup_ipv6.c new file mode 100644 index 000000000000..c8ab626556a0 --- /dev/null +++ b/net/ipv6/netfilter/nf_dup_ipv6.c @@ -0,0 +1,97 @@ +/* + * (C) 2007 by Sebastian Claßen <sebastian.classen@freenet.ag> + * (C) 2007-2010 by Jan Engelhardt <jengelh@medozas.de> + * + * Extracted from xt_TEE.c + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 or later, as + * published by the Free Software Foundation. + */ +#include <linux/module.h> +#include <linux/percpu.h> +#include <linux/skbuff.h> +#include <linux/netfilter.h> +#include <net/ipv6.h> +#include <net/ip6_route.h> +#include <net/netfilter/ipv6/nf_dup_ipv6.h> +#if IS_ENABLED(CONFIG_NF_CONNTRACK) +#include <net/netfilter/nf_conntrack.h> +#endif + +static struct net *pick_net(struct sk_buff *skb) +{ +#ifdef CONFIG_NET_NS + const struct dst_entry *dst; + + if (skb->dev != NULL) + return dev_net(skb->dev); + dst = skb_dst(skb); + if (dst != NULL && dst->dev != NULL) + return dev_net(dst->dev); +#endif + return &init_net; +} + +static bool nf_dup_ipv6_route(struct sk_buff *skb, const struct in6_addr *gw, + int oif) +{ + const struct ipv6hdr *iph = ipv6_hdr(skb); + struct net *net = pick_net(skb); + struct dst_entry *dst; + struct flowi6 fl6; + + memset(&fl6, 0, sizeof(fl6)); + if (oif != -1) + fl6.flowi6_oif = oif; + + fl6.daddr = *gw; + fl6.flowlabel = (__force __be32)(((iph->flow_lbl[0] & 0xF) << 16) | + (iph->flow_lbl[1] << 8) | iph->flow_lbl[2]); + dst = ip6_route_output(net, NULL, &fl6); + if (dst->error) { + dst_release(dst); + return false; + } + skb_dst_drop(skb); + skb_dst_set(skb, dst); + skb->dev = dst->dev; + skb->protocol = htons(ETH_P_IPV6); + + return true; +} + +void nf_dup_ipv6(struct sk_buff *skb, unsigned int hooknum, + const struct in6_addr *gw, int oif) +{ + if (this_cpu_read(nf_skb_duplicated)) + return; + skb = pskb_copy(skb, GFP_ATOMIC); + if (skb == NULL) + return; + +#if IS_ENABLED(CONFIG_NF_CONNTRACK) + nf_conntrack_put(skb->nfct); + skb->nfct = &nf_ct_untracked_get()->ct_general; + skb->nfctinfo = IP_CT_NEW; + nf_conntrack_get(skb->nfct); +#endif + if (hooknum == NF_INET_PRE_ROUTING || + hooknum == NF_INET_LOCAL_IN) { + struct ipv6hdr *iph = ipv6_hdr(skb); + --iph->hop_limit; + } + if (nf_dup_ipv6_route(skb, gw, oif)) { + __this_cpu_write(nf_skb_duplicated, true); + ip6_local_out(skb); + __this_cpu_write(nf_skb_duplicated, false); + } else { + kfree_skb(skb); + } +} +EXPORT_SYMBOL_GPL(nf_dup_ipv6); + +MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@freenet.ag>"); +MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); +MODULE_DESCRIPTION("nf_dup_ipv6: IPv6 packet duplication"); +MODULE_LICENSE("GPL"); |