[PATCH 12/19] netfilter: ipv6: add IPv6 NAT support

kaber
2012-08-09T20:18:38Z

From: Patrick McHardy <kaber@trash.net>

Signed-off-by: Patrick McHardy <kaber@trash.net>
---
include/linux/netfilter/nfnetlink_conntrack.h | 2 +
include/net/netfilter/nf_nat_l3proto.h | 5 +
include/net/netfilter/nf_nat_l4proto.h | 1 +
include/net/netns/ipv6.h | 1 +
net/core/secure_seq.c | 1 +
net/ipv6/netfilter/Kconfig | 12 +
net/ipv6/netfilter/Makefile | 4 +
net/ipv6/netfilter/ip6table_nat.c | 321 ++++++++++++++++++++++++
net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c | 39 +++-
net/ipv6/netfilter/nf_nat_l3proto_ipv6.c | 287 +++++++++++++++++++++
net/ipv6/netfilter/nf_nat_proto_icmpv6.c | 90 +++++++
11 files changed, 761 insertions(+), 2 deletions(-)
create mode 100644 net/ipv6/netfilter/ip6table_nat.c
create mode 100644 net/ipv6/netfilter/nf_nat_l3proto_ipv6.c
create mode 100644 net/ipv6/netfilter/nf_nat_proto_icmpv6.c

diff --git a/include/linux/netfilter/nfnetlink_conntrack.h b/include/linux/netfilter/nfnetlink_conntrack.h
index 68920ea..43bfe3e 100644
--- a/include/linux/netfilter/nfnetlink_conntrack.h
+++ b/include/linux/netfilter/nfnetlink_conntrack.h
@@ -147,6 +147,8 @@ enum ctattr_nat {
CTA_NAT_V4_MAXIP,
#define CTA_NAT_MAXIP CTA_NAT_V4_MAXIP
CTA_NAT_PROTO,
+ CTA_NAT_V6_MINIP,
+ CTA_NAT_V6_MAXIP,
__CTA_NAT_MAX
};
#define CTA_NAT_MAX (__CTA_NAT_MAX - 1)
diff --git a/include/net/netfilter/nf_nat_l3proto.h b/include/net/netfilter/nf_nat_l3proto.h
index 3df4a67..57d9e27 100644
--- a/include/net/netfilter/nf_nat_l3proto.h
+++ b/include/net/netfilter/nf_nat_l3proto.h
@@ -43,5 +43,10 @@ extern int nf_nat_icmp_reply_translation(struct sk_buff *skb,
struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
unsigned int hooknum);
+extern int nf_nat_icmpv6_reply_translation(struct sk_buff *skb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned int hooknum,
+ unsigned int hdrlen);

#endif /* _NF_NAT_L3PROTO_H */
diff --git a/include/net/netfilter/nf_nat_l4proto.h b/include/net/netfilter/nf_nat_l4proto.h
index 1f0a4f0..24feb68 100644
--- a/include/net/netfilter/nf_nat_l4proto.h
+++ b/include/net/netfilter/nf_nat_l4proto.h
@@ -51,6 +51,7 @@ extern const struct nf_nat_l4proto *__nf_nat_l4proto_find(u8 l3proto, u8 l4proto
extern const struct nf_nat_l4proto nf_nat_l4proto_tcp;
extern const struct nf_nat_l4proto nf_nat_l4proto_udp;
extern const struct nf_nat_l4proto nf_nat_l4proto_icmp;
+extern const struct nf_nat_l4proto nf_nat_l4proto_icmpv6;
extern const struct nf_nat_l4proto nf_nat_l4proto_unknown;

extern bool nf_nat_l4proto_in_range(const struct nf_conntrack_tuple *tuple,
diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index df0a545..0318104 100644
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -42,6 +42,7 @@ struct netns_ipv6 {
#ifdef CONFIG_SECURITY
struct xt_table *ip6table_security;
#endif
+ struct xt_table *ip6table_nat;
#endif
struct rt6_info *ip6_null_entry;
struct rt6_statistics *rt6_stats;
diff --git a/net/core/secure_seq.c b/net/core/secure_seq.c
index 99b2596..e61a8bb 100644
--- a/net/core/secure_seq.c
+++ b/net/core/secure_seq.c
@@ -76,6 +76,7 @@ u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,

return hash[0];
}
+EXPORT_SYMBOL(secure_ipv6_port_ephemeral);
#endif

#ifdef CONFIG_INET
diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig
index 1013534..b27e0ad 100644
--- a/net/ipv6/netfilter/Kconfig
+++ b/net/ipv6/netfilter/Kconfig
@@ -25,6 +25,18 @@ config NF_CONNTRACK_IPV6

To compile it as a module, choose M here. If unsure, say N.

+config NF_NAT_IPV6
+ tristate "IPv6 NAT"
+ depends on NF_CONNTRACK_IPV6
+ depends on NETFILTER_ADVANCED
+ select NF_NAT
+ help
+ The IPv6 NAT option allows masquerading, port forwarding and other
+ forms of full Network Address Port Translation. It is controlled by
+ the `nat' table in ip6tables, see the man page for ip6tables(8).
+
+ To compile it as a module, choose M here. If unsure, say N.
+
config IP6_NF_IPTABLES
tristate "IP6 tables support (required for filtering)"
depends on INET && IPV6
diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile
index 534d3f2..7677937 100644
--- a/net/ipv6/netfilter/Makefile
+++ b/net/ipv6/netfilter/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_IP6_NF_FILTER) += ip6table_filter.o
obj-$(CONFIG_IP6_NF_MANGLE) += ip6table_mangle.o
obj-$(CONFIG_IP6_NF_RAW) += ip6table_raw.o
obj-$(CONFIG_IP6_NF_SECURITY) += ip6table_security.o
+obj-$(CONFIG_NF_NAT_IPV6) += ip6table_nat.o

# objects for l3 independent conntrack
nf_conntrack_ipv6-y := nf_conntrack_l3proto_ipv6.o nf_conntrack_proto_icmpv6.o
@@ -15,6 +16,9 @@ nf_conntrack_ipv6-y := nf_conntrack_l3proto_ipv6.o nf_conntrack_proto_icmpv6.o
# l3 independent conntrack
obj-$(CONFIG_NF_CONNTRACK_IPV6) += nf_conntrack_ipv6.o nf_defrag_ipv6.o

+nf_nat_ipv6-y := nf_nat_l3proto_ipv6.o nf_nat_proto_icmpv6.o
+obj-$(CONFIG_NF_NAT_IPV6) += nf_nat_ipv6.o
+
# defrag
nf_defrag_ipv6-y := nf_defrag_ipv6_hooks.o nf_conntrack_reasm.o
obj-$(CONFIG_NF_DEFRAG_IPV6) += nf_defrag_ipv6.o
diff --git a/net/ipv6/netfilter/ip6table_nat.c b/net/ipv6/netfilter/ip6table_nat.c
new file mode 100644
index 0000000..b3f710e
--- /dev/null
+++ b/net/ipv6/netfilter/ip6table_nat.c
@@ -0,0 +1,321 @@
+/*
+ * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Based on Rusty Russell's IPv4 NAT code. Development of IPv6 NAT
+ * funded by Astaro.
+ */
+
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv6.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <linux/ipv6.h>
+#include <net/ipv6.h>
+
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_l3proto.h>
+
+static const struct xt_table nf_nat_ipv6_table = {
+ .name = "nat",
+ .valid_hooks = (1 << NF_INET_PRE_ROUTING) |
+ (1 << NF_INET_POST_ROUTING) |
+ (1 << NF_INET_LOCAL_OUT) |
+ (1 << NF_INET_LOCAL_IN),
+ .me = THIS_MODULE,
+ .af = NFPROTO_IPV6,
+};
+
+static unsigned int alloc_null_binding(struct nf_conn *ct, unsigned int hooknum)
+{
+ /* Force range to this IP; let proto decide mapping for
+ * per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
+ */
+ struct nf_nat_range range;
+
+ range.flags = 0;
+ pr_debug("Allocating NULL binding for %p (%pI6)\n", ct,
+ HOOK2MANIP(hooknum) == NF_NAT_MANIP_SRC ?
+ &ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip6 :
+ &ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip6);
+
+ return nf_nat_setup_info(ct, &range, HOOK2MANIP(hooknum));
+}
+
+static unsigned int nf_nat_rule_find(struct sk_buff *skb, unsigned int hooknum,
+ const struct net_device *in,
+ const struct net_device *out,
+ struct nf_conn *ct)
+{
+ struct net *net = nf_ct_net(ct);
+ unsigned int ret;
+
+ ret = ip6t_do_table(skb, hooknum, in, out, net->ipv6.ip6table_nat);
+ if (ret == NF_ACCEPT) {
+ if (!nf_nat_initialized(ct, HOOK2MANIP(hooknum)))
+ ret = alloc_null_binding(ct, hooknum);
+ }
+ return ret;
+}
+
+static unsigned int
+nf_nat_ipv6_fn(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn_nat *nat;
+ enum nf_nat_manip_type maniptype = HOOK2MANIP(hooknum);
+ __be16 frag_off;
+ int hdrlen;
+ u8 nexthdr;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ /* Can't track? It's not due to stress, or conntrack would
+ * have dropped it. Hence it's the user's responsibilty to
+ * packet filter it out, or implement conntrack/NAT for that
+ * protocol. 8) --RR
+ */
+ if (!ct)
+ return NF_ACCEPT;
+
+ /* Don't try to NAT if this packet is not conntracked */
+ if (nf_ct_is_untracked(ct))
+ return NF_ACCEPT;
+
+ nat = nfct_nat(ct);
+ if (!nat) {
+ /* NAT module was loaded late. */
+ if (nf_ct_is_confirmed(ct))
+ return NF_ACCEPT;
+ nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
+ if (nat == NULL) {
+ pr_debug("failed to add NAT extension\n");
+ return NF_ACCEPT;
+ }
+ }
+
+ switch (ctinfo) {
+ case IP_CT_RELATED:
+ case IP_CT_RELATED_REPLY:
+ nexthdr = ipv6_hdr(skb)->nexthdr;
+ hdrlen = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
+ &nexthdr, &frag_off);
+
+ if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
+ if (!nf_nat_icmpv6_reply_translation(skb, ct, ctinfo,
+ hooknum, hdrlen))
+ return NF_DROP;
+ else
+ return NF_ACCEPT;
+ }
+ /* Fall thru... (Only ICMPs can be IP_CT_IS_REPLY) */
+ case IP_CT_NEW:
+ /* Seen it before? This can happen for loopback, retrans,
+ * or local packets.
+ */
+ if (!nf_nat_initialized(ct, maniptype)) {
+ unsigned int ret;
+
+ ret = nf_nat_rule_find(skb, hooknum, in, out, ct);
+ if (ret != NF_ACCEPT)
+ return ret;
+ } else
+ pr_debug("Already setup manip %s for ct %p\n",
+ maniptype == NF_NAT_MANIP_SRC ? "SRC" : "DST",
+ ct);
+ break;
+
+ default:
+ /* ESTABLISHED */
+ NF_CT_ASSERT(ctinfo == IP_CT_ESTABLISHED ||
+ ctinfo == IP_CT_ESTABLISHED_REPLY);
+ }
+
+ return nf_nat_packet(ct, ctinfo, hooknum, skb);
+}
+
+static unsigned int
+nf_nat_ipv6_in(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ unsigned int ret;
+ struct in6_addr daddr = ipv6_hdr(skb)->daddr;
+
+ ret = nf_nat_ipv6_fn(hooknum, skb, in, out, okfn);
+ if (ret != NF_DROP && ret != NF_STOLEN &&
+ ipv6_addr_cmp(&daddr, &ipv6_hdr(skb)->daddr))
+ skb_dst_drop(skb);
+
+ return ret;
+}
+
+static unsigned int
+nf_nat_ipv6_out(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+#ifdef CONFIG_XFRM
+ const struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+#endif
+ unsigned int ret;
+
+ /* root is playing with raw sockets. */
+ if (skb->len < sizeof(struct ipv6hdr))
+ return NF_ACCEPT;
+
+ ret = nf_nat_ipv6_fn(hooknum, skb, in, out, okfn);
+#ifdef CONFIG_XFRM
+ if (ret != NF_DROP && ret != NF_STOLEN &&
+ !(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
+ (ct = nf_ct_get(skb, &ctinfo)) != NULL) {
+ enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+
+ if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3,
+ &ct->tuplehash[!dir].tuple.dst.u3) ||
+ (ct->tuplehash[dir].tuple.src.u.all !=
+ ct->tuplehash[!dir].tuple.dst.u.all))
+ if (nf_xfrm_me_harder(skb, AF_INET6) < 0)
+ ret = NF_DROP;
+ }
+#endif
+ return ret;
+}
+
+static unsigned int
+nf_nat_ipv6_local_fn(unsigned int hooknum,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ const struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+ unsigned int ret;
+
+ /* root is playing with raw sockets. */
+ if (skb->len < sizeof(struct ipv6hdr))
+ return NF_ACCEPT;
+
+ ret = nf_nat_ipv6_fn(hooknum, skb, in, out, okfn);
+ if (ret != NF_DROP && ret != NF_STOLEN &&
+ (ct = nf_ct_get(skb, &ctinfo)) != NULL) {
+ enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+
+ if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3,
+ &ct->tuplehash[!dir].tuple.src.u3)) {
+ if (ip6_route_me_harder(skb))
+ ret = NF_DROP;
+ }
+#ifdef CONFIG_XFRM
+ else if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
+ ct->tuplehash[dir].tuple.dst.u.all !=
+ ct->tuplehash[!dir].tuple.src.u.all)
+ if (nf_xfrm_me_harder(skb, AF_INET6))
+ ret = NF_DROP;
+#endif
+ }
+ return ret;
+}
+
+static struct nf_hook_ops nf_nat_ipv6_ops[] __read_mostly = {
+ /* Before packet filtering, change destination */
+ {
+ .hook = nf_nat_ipv6_in,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV6,
+ .hooknum = NF_INET_PRE_ROUTING,
+ .priority = NF_IP_PRI_NAT_DST,
+ },
+ /* After packet filtering, change source */
+ {
+ .hook = nf_nat_ipv6_out,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV6,
+ .hooknum = NF_INET_POST_ROUTING,
+ .priority = NF_IP_PRI_NAT_SRC,
+ },
+ /* Before packet filtering, change destination */
+ {
+ .hook = nf_nat_ipv6_local_fn,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV6,
+ .hooknum = NF_INET_LOCAL_OUT,
+ .priority = NF_IP_PRI_NAT_DST,
+ },
+ /* After packet filtering, change source */
+ {
+ .hook = nf_nat_ipv6_fn,
+ .owner = THIS_MODULE,
+ .pf = NFPROTO_IPV6,
+ .hooknum = NF_INET_LOCAL_IN,
+ .priority = NF_IP_PRI_NAT_SRC,
+ },
+};
+
+static int __net_init ip6table_nat_net_init(struct net *net)
+{
+ struct ip6t_replace *repl;
+
+ repl = ip6t_alloc_initial_table(&nf_nat_ipv6_table);
+ if (repl == NULL)
+ return -ENOMEM;
+ net->ipv6.ip6table_nat = ip6t_register_table(net, &nf_nat_ipv6_table, repl);
+ kfree(repl);
+ if (IS_ERR(net->ipv6.ip6table_nat))
+ return PTR_ERR(net->ipv6.ip6table_nat);
+ return 0;
+}
+
+static void __net_exit ip6table_nat_net_exit(struct net *net)
+{
+ ip6t_unregister_table(net, net->ipv6.ip6table_nat);
+}
+
+static struct pernet_operations ip6table_nat_net_ops = {
+ .init = ip6table_nat_net_init,
+ .exit = ip6table_nat_net_exit,
+};
+
+static int __init ip6table_nat_init(void)
+{
+ int err;
+
+ err = register_pernet_subsys(&ip6table_nat_net_ops);
+ if (err < 0)
+ goto err1;
+
+ err = nf_register_hooks(nf_nat_ipv6_ops, ARRAY_SIZE(nf_nat_ipv6_ops));
+ if (err < 0)
+ goto err2;
+ return 0;
+
+err2:
+ unregister_pernet_subsys(&ip6table_nat_net_ops);
+err1:
+ return err;
+}
+
+static void __exit ip6table_nat_exit(void)
+{
+ nf_unregister_hooks(nf_nat_ipv6_ops, ARRAY_SIZE(nf_nat_ipv6_ops));
+ unregister_pernet_subsys(&ip6table_nat_net_ops);
+}
+
+module_init(ip6table_nat_init);
+module_exit(ip6table_nat_exit);
+
+MODULE_LICENSE("GPL");
diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
index 4d92ea6..9f427b5 100644
--- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
@@ -28,6 +28,7 @@
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
+#include <net/netfilter/nf_nat_helper.h>
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
#include <net/netfilter/nf_log.h>

@@ -142,6 +143,36 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+ unsigned char pnum = ipv6_hdr(skb)->nexthdr;
+ int protoff;
+ __be16 frag_off;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (!ct || ctinfo == IP_CT_RELATED_REPLY)
+ goto out;
+
+ protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum,
+ &frag_off);
+ if (protoff < 0 || (frag_off & ntohs(~0x7)) != 0) {
+ pr_debug("proto header not found\n");
+ goto out;
+ }
+
+ /* adjust seqs for loopback traffic only in outgoing direction */
+ if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
+ !nf_is_loopback_packet(skb)) {
+ typeof(nf_nat_seq_adjust_hook) seq_adjust;
+
+ seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook);
+ if (!seq_adjust ||
+ !seq_adjust(skb, ct, ctinfo, protoff)) {
+ NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
+ return NF_DROP;
+ }
+ }
+out:
/* We've seen it coming out the other side: confirm it */
return nf_conntrack_confirm(skb);
}
@@ -169,10 +200,14 @@ static unsigned int __ipv6_conntrack_in(struct net *net,
}

/* Conntrack helpers need the entire reassembled packet in the
- * POST_ROUTING hook.
+ * POST_ROUTING hook. In case of unconfirmed connections NAT
+ * might reassign a helper, so the entire packet is also
+ * required.
*/
ct = nf_ct_get(reasm, &ctinfo);
- if (ct != NULL && test_bit(IPS_HELPER_BIT, &ct->status)) {
+ if (ct != NULL &&
+ (test_bit(IPS_HELPER_BIT, &ct->status) ||
+ !nf_ct_is_confirmed(ct))) {
nf_conntrack_get_reasm(skb);
NF_HOOK_THRESH(NFPROTO_IPV6, hooknum, reasm,
(struct net_device *)in,
diff --git a/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c b/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c
new file mode 100644
index 0000000..4d42eaa
--- /dev/null
+++ b/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c
@@ -0,0 +1,287 @@
+/*
+ * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Development of IPv6 NAT funded by Astaro.
+ */
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ipv6.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv6.h>
+#include <net/secure_seq.h>
+#include <net/checksum.h>
+#include <net/ip6_route.h>
+#include <net/ipv6.h>
+
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_l3proto.h>
+#include <net/netfilter/nf_nat_l4proto.h>
+
+static const struct nf_nat_l3proto nf_nat_l3proto_ipv6;
+
+#ifdef CONFIG_XFRM
+static void nf_nat_ipv6_decode_session(struct sk_buff *skb,
+ const struct nf_conn *ct,
+ enum ip_conntrack_dir dir,
+ unsigned long statusbit,
+ struct flowi *fl)
+{
+ const struct nf_conntrack_tuple *t = &ct->tuplehash[dir].tuple;
+ struct flowi6 *fl6 = &fl->u.ip6;
+
+ if (ct->status & statusbit) {
+ fl6->daddr = t->dst.u3.in6;
+ if (t->dst.protonum == IPPROTO_TCP ||
+ t->dst.protonum == IPPROTO_UDP ||
+ t->dst.protonum == IPPROTO_UDPLITE ||
+ t->dst.protonum == IPPROTO_DCCP ||
+ t->dst.protonum == IPPROTO_SCTP)
+ fl6->fl6_dport = t->dst.u.all;
+ }
+
+ statusbit ^= IPS_NAT_MASK;
+
+ if (ct->status & statusbit) {
+ fl6->saddr = t->src.u3.in6;
+ if (t->dst.protonum == IPPROTO_TCP ||
+ t->dst.protonum == IPPROTO_UDP ||
+ t->dst.protonum == IPPROTO_UDPLITE ||
+ t->dst.protonum == IPPROTO_DCCP ||
+ t->dst.protonum == IPPROTO_SCTP)
+ fl6->fl6_sport = t->src.u.all;
+ }
+}
+#endif
+
+static int nf_nat_ipv6_in_range(const struct nf_conntrack_tuple *t,
+ const struct nf_nat_range *range)
+{
+ return ipv6_addr_cmp(&t->src.u3.in6, &range->min_addr.in6) >= 0 &&
+ ipv6_addr_cmp(&t->src.u3.in6, &range->max_addr.in6) <= 0;
+}
+
+static u32 nf_nat_ipv6_secure_port(const struct nf_conntrack_tuple *t,
+ __be16 dport)
+{
+ return secure_ipv6_port_ephemeral(t->src.u3.ip6, t->dst.u3.ip6, dport);
+}
+
+static bool nf_nat_ipv6_manip_pkt(struct sk_buff *skb,
+ unsigned int iphdroff,
+ const struct nf_nat_l4proto *l4proto,
+ const struct nf_conntrack_tuple *target,
+ enum nf_nat_manip_type maniptype)
+{
+ struct ipv6hdr *ipv6h;
+ __be16 frag_off;
+ int hdroff;
+ u8 nexthdr;
+
+ if (!skb_make_writable(skb, iphdroff + sizeof(*ipv6h)))
+ return false;
+
+ ipv6h = (void *)skb->data + iphdroff;
+ nexthdr = ipv6h->nexthdr;
+ hdroff = ipv6_skip_exthdr(skb, iphdroff + sizeof(*ipv6h),
+ &nexthdr, &frag_off);
+ if (hdroff < 0)
+ goto manip_addr;
+
+ if ((frag_off & htons(~0x7)) == 0 &&
+ !l4proto->manip_pkt(skb, &nf_nat_l3proto_ipv6, iphdroff, hdroff,
+ target, maniptype))
+ return false;
+manip_addr:
+ if (maniptype == NF_NAT_MANIP_SRC)
+ ipv6h->saddr = target->src.u3.in6;
+ else
+ ipv6h->daddr = target->dst.u3.in6;
+
+ return true;
+}
+
+static void nf_nat_ipv6_csum_update(struct sk_buff *skb,
+ unsigned int iphdroff, __sum16 *check,
+ const struct nf_conntrack_tuple *t,
+ enum nf_nat_manip_type maniptype)
+{
+ const struct ipv6hdr *ipv6h = (struct ipv6hdr *)(skb->data + iphdroff);
+ const struct in6_addr *oldip, *newip;
+
+ if (maniptype == NF_NAT_MANIP_SRC) {
+ oldip = &ipv6h->saddr;
+ newip = &t->src.u3.in6;
+ } else {
+ oldip = &ipv6h->daddr;
+ newip = &t->dst.u3.in6;
+ }
+ inet_proto_csum_replace16(check, skb, oldip->s6_addr32,
+ newip->s6_addr32, 1);
+}
+
+static void nf_nat_ipv6_csum_recalc(struct sk_buff *skb,
+ u8 proto, void *data, __sum16 *check,
+ int datalen, int oldlen)
+{
+ const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+ struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
+
+ if (skb->ip_summed != CHECKSUM_PARTIAL) {
+ if (!(rt->rt6i_flags & RTF_LOCAL) &&
+ (!skb->dev || skb->dev->features & NETIF_F_V6_CSUM)) {
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = skb_headroom(skb) +
+ skb_network_offset(skb) +
+ (data - (void *)skb->data);
+ skb->csum_offset = (void *)check - data;
+ *check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
+ datalen, proto, 0);
+ } else {
+ *check = 0;
+ *check = csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
+ datalen, proto,
+ csum_partial(data, datalen,
+ 0));
+ if (proto == IPPROTO_UDP && !*check)
+ *check = CSUM_MANGLED_0;
+ }
+ } else
+ inet_proto_csum_replace2(check, skb,
+ htons(oldlen), htons(datalen), 1);
+}
+
+static int nf_nat_ipv6_nlattr_to_range(struct nlattr *tb[],
+ struct nf_nat_range *range)
+{
+ if (tb[CTA_NAT_V6_MINIP]) {
+ nla_memcpy(&range->min_addr.ip6, tb[CTA_NAT_V6_MINIP],
+ sizeof(struct in6_addr));
+ range->flags |= NF_NAT_RANGE_MAP_IPS;
+ }
+
+ if (tb[CTA_NAT_V6_MAXIP])
+ nla_memcpy(&range->max_addr.ip6, tb[CTA_NAT_V6_MAXIP],
+ sizeof(struct in6_addr));
+ else
+ range->max_addr = range->min_addr;
+
+ return 0;
+}
+
+static const struct nf_nat_l3proto nf_nat_l3proto_ipv6 = {
+ .l3proto = NFPROTO_IPV6,
+ .secure_port = nf_nat_ipv6_secure_port,
+ .in_range = nf_nat_ipv6_in_range,
+ .manip_pkt = nf_nat_ipv6_manip_pkt,
+ .csum_update = nf_nat_ipv6_csum_update,
+ .csum_recalc = nf_nat_ipv6_csum_recalc,
+ .nlattr_to_range = nf_nat_ipv6_nlattr_to_range,
+#ifdef CONFIG_XFRM
+ .decode_session = nf_nat_ipv6_decode_session,
+#endif
+};
+
+int nf_nat_icmpv6_reply_translation(struct sk_buff *skb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned int hooknum,
+ unsigned int hdrlen)
+{
+ struct {
+ struct icmp6hdr icmp6;
+ struct ipv6hdr ip6;
+ } *inside;
+ enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+ enum nf_nat_manip_type manip = HOOK2MANIP(hooknum);
+ const struct nf_nat_l4proto *l4proto;
+ struct nf_conntrack_tuple target;
+ unsigned long statusbit;
+
+ NF_CT_ASSERT(ctinfo == IP_CT_RELATED || ctinfo == IP_CT_RELATED_REPLY);
+
+ if (!skb_make_writable(skb, hdrlen + sizeof(*inside)))
+ return 0;
+ if (nf_ip6_checksum(skb, hooknum, hdrlen, IPPROTO_ICMPV6))
+ return 0;
+
+ inside = (void *)skb->data + hdrlen;
+ if (inside->icmp6.icmp6_type == NDISC_REDIRECT) {
+ if ((ct->status & IPS_NAT_DONE_MASK) != IPS_NAT_DONE_MASK)
+ return 0;
+ if (ct->status & IPS_NAT_MASK)
+ return 0;
+ }
+
+ if (manip == NF_NAT_MANIP_SRC)
+ statusbit = IPS_SRC_NAT;
+ else
+ statusbit = IPS_DST_NAT;
+
+ /* Invert if this is reply direction */
+ if (dir == IP_CT_DIR_REPLY)
+ statusbit ^= IPS_NAT_MASK;
+
+ if (!(ct->status & statusbit))
+ return 1;
+
+ l4proto = __nf_nat_l4proto_find(NFPROTO_IPV6, inside->ip6.nexthdr);
+ if (!nf_nat_ipv6_manip_pkt(skb, hdrlen + sizeof(inside->icmp6),
+ l4proto, &ct->tuplehash[!dir].tuple, !manip))
+ return 0;
+
+ if (skb->ip_summed != CHECKSUM_PARTIAL) {
+ struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+ inside = (void *)skb->data + hdrlen;
+ inside->icmp6.icmp6_cksum = 0;
+ inside->icmp6.icmp6_cksum =
+ csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
+ skb->len - hdrlen, IPPROTO_ICMPV6,
+ csum_partial(&inside->icmp6,
+ skb->len - hdrlen, 0));
+ }
+
+ nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
+ l4proto = __nf_nat_l4proto_find(NFPROTO_IPV6, IPPROTO_ICMPV6);
+ if (!nf_nat_ipv6_manip_pkt(skb, 0, l4proto, &target, manip))
+ return 0;
+
+ return 1;
+}
+EXPORT_SYMBOL_GPL(nf_nat_icmpv6_reply_translation);
+
+static int __init nf_nat_l3proto_ipv6_init(void)
+{
+ int err;
+
+ err = nf_nat_l4proto_register(NFPROTO_IPV6, &nf_nat_l4proto_icmpv6);
+ if (err < 0)
+ goto err1;
+ err = nf_nat_l3proto_register(&nf_nat_l3proto_ipv6);
+ if (err < 0)
+ goto err2;
+ return err;
+
+err2:
+ nf_nat_l4proto_unregister(NFPROTO_IPV6, &nf_nat_l4proto_icmpv6);
+err1:
+ return err;
+}
+
+static void __exit nf_nat_l3proto_ipv6_exit(void)
+{
+ nf_nat_l3proto_unregister(&nf_nat_l3proto_ipv6);
+ nf_nat_l4proto_unregister(NFPROTO_IPV6, &nf_nat_l4proto_icmpv6);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("nf-nat-" __stringify(AF_INET6));
+
+module_init(nf_nat_l3proto_ipv6_init);
+module_exit(nf_nat_l3proto_ipv6_exit);
diff --git a/net/ipv6/netfilter/nf_nat_proto_icmpv6.c b/net/ipv6/netfilter/nf_nat_proto_icmpv6.c
new file mode 100644
index 0000000..5d6da78
--- /dev/null
+++ b/net/ipv6/netfilter/nf_nat_proto_icmpv6.c
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2011 Patrick Mchardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Based on Rusty Russell's IPv4 ICMP NAT code. Development of IPv6
+ * NAT funded by Astaro.
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/icmpv6.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_l3proto.h>
+#include <net/netfilter/nf_nat_l4proto.h>
+
+static bool
+icmpv6_in_range(const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype,
+ const union nf_conntrack_man_proto *min,
+ const union nf_conntrack_man_proto *max)
+{
+ return ntohs(tuple->src.u.icmp.id) >= ntohs(min->icmp.id) &&
+ ntohs(tuple->src.u.icmp.id) <= ntohs(max->icmp.id);
+}
+
+static void
+icmpv6_unique_tuple(const struct nf_nat_l3proto *l3proto,
+ struct nf_conntrack_tuple *tuple,
+ const struct nf_nat_range *range,
+ enum nf_nat_manip_type maniptype,
+ const struct nf_conn *ct)
+{
+ static u16 id;
+ unsigned int range_size;
+ unsigned int i;
+
+ range_size = ntohs(range->max_proto.icmp.id) -
+ ntohs(range->min_proto.icmp.id) + 1;
+
+ if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED))
+ range_size = 0xffff;
+
+ for (i = 0; ; ++id) {
+ tuple->src.u.icmp.id = htons(ntohs(range->min_proto.icmp.id) +
+ (id % range_size));
+ if (++i == range_size || !nf_nat_used_tuple(tuple, ct))
+ return;
+ }
+}
+
+static bool
+icmpv6_manip_pkt(struct sk_buff *skb,
+ const struct nf_nat_l3proto *l3proto,
+ unsigned int iphdroff, unsigned int hdroff,
+ const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype)
+{
+ struct icmp6hdr *hdr;
+
+ if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
+ return false;
+
+ hdr = (struct icmp6hdr *)(skb->data + hdroff);
+ l3proto->csum_update(skb, iphdroff, &hdr->icmp6_cksum,
+ tuple, maniptype);
+ if (hdr->icmp6_code == ICMPV6_ECHO_REQUEST ||
+ hdr->icmp6_code == ICMPV6_ECHO_REPLY) {
+ inet_proto_csum_replace2(&hdr->icmp6_cksum, skb,
+ hdr->icmp6_identifier,
+ tuple->src.u.icmp.id, 0);
+ hdr->icmp6_identifier = tuple->src.u.icmp.id;
+ }
+ return true;
+}
+
+const struct nf_nat_l4proto nf_nat_l4proto_icmpv6 = {
+ .l4proto = IPPROTO_ICMPV6,
+ .manip_pkt = icmpv6_manip_pkt,
+ .in_range = icmpv6_in_range,
+ .unique_tuple = icmpv6_unique_tuple,
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+ .nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
+#endif
+};
--
1.7.1