| /* |
| * (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 bool nf_dup_ipv6_route(struct net *net, struct sk_buff *skb, |
| const struct in6_addr *gw, int oif) |
| { |
| const struct ipv6hdr *iph = ipv6_hdr(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]); |
| fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH; |
| 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 net *net, 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_reset(skb); |
| nf_ct_set(skb, NULL, IP_CT_UNTRACKED); |
| #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(net, skb, gw, oif)) { |
| __this_cpu_write(nf_skb_duplicated, true); |
| ip6_local_out(net, skb->sk, 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"); |