diff options
author | Patrick McHardy <kaber@trash.net> | 2012-08-26 19:14:12 +0200 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2012-08-30 03:00:17 +0200 |
commit | 58a317f1061c894d2344c0b6a18ab4a64b69b815 (patch) | |
tree | 0e8c4dd2a74cff86cedca36de278e3eb42f939bd /net/ipv6/netfilter | |
parent | 2cf545e835aae92173ef0b1f4af385e9c40f21e8 (diff) | |
download | op-kernel-dev-58a317f1061c894d2344c0b6a18ab4a64b69b815.zip op-kernel-dev-58a317f1061c894d2344c0b6a18ab4a64b69b815.tar.gz |
netfilter: ipv6: add IPv6 NAT support
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/ipv6/netfilter')
-rw-r--r-- | net/ipv6/netfilter/Kconfig | 12 | ||||
-rw-r--r-- | net/ipv6/netfilter/Makefile | 4 | ||||
-rw-r--r-- | net/ipv6/netfilter/ip6table_nat.c | 321 | ||||
-rw-r--r-- | net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c | 37 | ||||
-rw-r--r-- | net/ipv6/netfilter/nf_nat_l3proto_ipv6.c | 287 | ||||
-rw-r--r-- | net/ipv6/netfilter/nf_nat_proto_icmpv6.c | 90 |
6 files changed, 749 insertions, 2 deletions
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..e418bd6 --- /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_IP6_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_IP6_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_IP6_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_IP6_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 dcf6010..8860d23 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 & htons(~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); } @@ -170,12 +201,14 @@ 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 && !nf_ct_is_untracked(ct)) { help = nfct_help(ct); - if (help && help->helper) { + if ((help && help->helper) || !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..81a2d1c --- /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 bool 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 +}; |