Pablo Neira Ayuso | bbde9fc | 2015-05-31 17:54:44 +0200 | [diff] [blame] | 1 | /* |
| 2 | * (C) 2007 by Sebastian Claßen <sebastian.classen@freenet.ag> |
| 3 | * (C) 2007-2010 by Jan Engelhardt <jengelh@medozas.de> |
| 4 | * |
| 5 | * Extracted from xt_TEE.c |
| 6 | * |
| 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. |
| 10 | */ |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/percpu.h> |
| 13 | #include <linux/skbuff.h> |
Daniel Borkmann | a82b0e6 | 2015-09-02 20:54:02 +0200 | [diff] [blame] | 14 | #include <linux/netfilter.h> |
Pablo Neira Ayuso | bbde9fc | 2015-05-31 17:54:44 +0200 | [diff] [blame] | 15 | #include <net/ipv6.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> |
| 20 | #endif |
| 21 | |
Eric W. Biederman | 206e8c0 | 2015-09-18 14:33:02 -0500 | [diff] [blame] | 22 | static bool nf_dup_ipv6_route(struct net *net, struct sk_buff *skb, |
| 23 | const struct in6_addr *gw, int oif) |
Pablo Neira Ayuso | bbde9fc | 2015-05-31 17:54:44 +0200 | [diff] [blame] | 24 | { |
| 25 | const struct ipv6hdr *iph = ipv6_hdr(skb); |
Pablo Neira Ayuso | bbde9fc | 2015-05-31 17:54:44 +0200 | [diff] [blame] | 26 | struct dst_entry *dst; |
| 27 | struct flowi6 fl6; |
| 28 | |
| 29 | memset(&fl6, 0, sizeof(fl6)); |
| 30 | if (oif != -1) |
| 31 | fl6.flowi6_oif = oif; |
| 32 | |
| 33 | fl6.daddr = *gw; |
Pablo Neira Ayuso | 59e2642 | 2015-08-21 21:28:10 +0200 | [diff] [blame] | 34 | fl6.flowlabel = (__force __be32)(((iph->flow_lbl[0] & 0xF) << 16) | |
| 35 | (iph->flow_lbl[1] << 8) | iph->flow_lbl[2]); |
Paolo Abeni | 83170f3 | 2016-05-26 19:08:10 +0200 | [diff] [blame] | 36 | fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH; |
Pablo Neira Ayuso | bbde9fc | 2015-05-31 17:54:44 +0200 | [diff] [blame] | 37 | dst = ip6_route_output(net, NULL, &fl6); |
| 38 | if (dst->error) { |
| 39 | dst_release(dst); |
| 40 | return false; |
| 41 | } |
| 42 | skb_dst_drop(skb); |
| 43 | skb_dst_set(skb, dst); |
| 44 | skb->dev = dst->dev; |
| 45 | skb->protocol = htons(ETH_P_IPV6); |
| 46 | |
| 47 | return true; |
| 48 | } |
| 49 | |
Eric W. Biederman | 206e8c0 | 2015-09-18 14:33:02 -0500 | [diff] [blame] | 50 | void nf_dup_ipv6(struct net *net, struct sk_buff *skb, unsigned int hooknum, |
Pablo Neira Ayuso | bbde9fc | 2015-05-31 17:54:44 +0200 | [diff] [blame] | 51 | const struct in6_addr *gw, int oif) |
| 52 | { |
Pablo Neira Ayuso | d877f07 | 2015-05-31 18:04:11 +0200 | [diff] [blame] | 53 | if (this_cpu_read(nf_skb_duplicated)) |
Pablo Neira Ayuso | bbde9fc | 2015-05-31 17:54:44 +0200 | [diff] [blame] | 54 | return; |
| 55 | skb = pskb_copy(skb, GFP_ATOMIC); |
| 56 | if (skb == NULL) |
| 57 | return; |
| 58 | |
| 59 | #if IS_ENABLED(CONFIG_NF_CONNTRACK) |
| 60 | nf_conntrack_put(skb->nfct); |
| 61 | skb->nfct = &nf_ct_untracked_get()->ct_general; |
| 62 | skb->nfctinfo = IP_CT_NEW; |
| 63 | nf_conntrack_get(skb->nfct); |
| 64 | #endif |
| 65 | if (hooknum == NF_INET_PRE_ROUTING || |
| 66 | hooknum == NF_INET_LOCAL_IN) { |
| 67 | struct ipv6hdr *iph = ipv6_hdr(skb); |
| 68 | --iph->hop_limit; |
| 69 | } |
Eric W. Biederman | 206e8c0 | 2015-09-18 14:33:02 -0500 | [diff] [blame] | 70 | if (nf_dup_ipv6_route(net, skb, gw, oif)) { |
Pablo Neira Ayuso | bbde9fc | 2015-05-31 17:54:44 +0200 | [diff] [blame] | 71 | __this_cpu_write(nf_skb_duplicated, true); |
Eric W. Biederman | 33224b1 | 2015-10-07 16:48:46 -0500 | [diff] [blame] | 72 | ip6_local_out(net, skb->sk, skb); |
Pablo Neira Ayuso | bbde9fc | 2015-05-31 17:54:44 +0200 | [diff] [blame] | 73 | __this_cpu_write(nf_skb_duplicated, false); |
| 74 | } else { |
| 75 | kfree_skb(skb); |
| 76 | } |
| 77 | } |
| 78 | EXPORT_SYMBOL_GPL(nf_dup_ipv6); |
| 79 | |
| 80 | MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@freenet.ag>"); |
| 81 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); |
| 82 | MODULE_DESCRIPTION("nf_dup_ipv6: IPv6 packet duplication"); |
| 83 | MODULE_LICENSE("GPL"); |