diff options
Diffstat (limited to 'net/netfilter')
| -rw-r--r-- | net/netfilter/Kconfig | 8 | ||||
| -rw-r--r-- | net/netfilter/nf_nat_core.c | 17 | ||||
| -rw-r--r-- | net/netfilter/nf_nat_proto.c | 678 |
3 files changed, 702 insertions, 1 deletions
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 5a753cec005b..5beb51d39dc2 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -396,7 +396,13 @@ config NETFILTER_NETLINK_GLUE_CT the enqueued via NFNETLINK. config NF_NAT - tristate + tristate "Network Address Translation support" + depends on NF_CONNTRACK + default m if NETFILTER_ADVANCED=n + help + The NAT option allows masquerading, port forwarding and other + forms of full Network Address Port Translation. This can be + controlled by iptables, ip6tables or nft. config NF_NAT_NEEDED bool diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 0f39ae7a9f34..0c548ff215b2 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -1203,6 +1203,8 @@ static struct nf_nat_hook nat_hook = { .manip_pkt = nf_nat_manip_pkt, }; +int nf_nat_l3proto_init(void); +void nf_nat_l3proto_exit(void); static int __init nf_nat_init(void) { int ret, i; @@ -1237,6 +1239,19 @@ static int __init nf_nat_init(void) WARN_ON(nf_nat_hook != NULL); RCU_INIT_POINTER(nf_nat_hook, &nat_hook); + ret = nf_nat_l3proto_init(); + if (ret) { + nf_ct_extend_unregister(&nat_extend); + nf_ct_helper_expectfn_unregister(&follow_master_nat); + RCU_INIT_POINTER(nf_nat_hook, NULL); + + synchronize_net(); + kvfree(nf_nat_bysource); + unregister_pernet_subsys(&nat_net_ops); + + return ret; + } + return 0; } @@ -1246,6 +1261,8 @@ static void __exit nf_nat_cleanup(void) nf_ct_iterate_destroy(nf_nat_proto_clean, &clean); + nf_nat_l3proto_exit(); + nf_ct_extend_unregister(&nat_extend); nf_ct_helper_expectfn_unregister(&follow_master_nat); RCU_INIT_POINTER(nf_nat_hook, NULL); diff --git a/net/netfilter/nf_nat_proto.c b/net/netfilter/nf_nat_proto.c index f83bf9d8c9f5..9c4db18741ef 100644 --- a/net/netfilter/nf_nat_proto.c +++ b/net/netfilter/nf_nat_proto.c @@ -24,6 +24,22 @@ #include <net/netfilter/nf_nat_l3proto.h> #include <net/netfilter/nf_nat_l4proto.h> +#include <linux/ipv6.h> +#include <linux/netfilter_ipv6.h> +#include <net/checksum.h> +#include <net/ip6_checksum.h> +#include <net/ip6_route.h> +#include <net/xfrm.h> +#include <net/ipv6.h> + +#include <net/netfilter/nf_conntrack_core.h> +#include <net/netfilter/nf_conntrack.h> + +static const struct nf_nat_l3proto nf_nat_l3proto_ipv4; +#if IS_ENABLED(CONFIG_IPV6) +static const struct nf_nat_l3proto nf_nat_l3proto_ipv6; +#endif + static void __udp_manip_pkt(struct sk_buff *skb, const struct nf_nat_l3proto *l3proto, @@ -341,3 +357,665 @@ bool nf_nat_l4proto_manip_pkt(struct sk_buff *skb, return true; } EXPORT_SYMBOL_GPL(nf_nat_l4proto_manip_pkt); + +static bool nf_nat_ipv4_manip_pkt(struct sk_buff *skb, + unsigned int iphdroff, + const struct nf_conntrack_tuple *target, + enum nf_nat_manip_type maniptype) +{ + struct iphdr *iph; + unsigned int hdroff; + + if (!skb_make_writable(skb, iphdroff + sizeof(*iph))) + return false; + + iph = (void *)skb->data + iphdroff; + hdroff = iphdroff + iph->ihl * 4; + + if (!nf_nat_l4proto_manip_pkt(skb, &nf_nat_l3proto_ipv4, iphdroff, + hdroff, target, maniptype)) + return false; + iph = (void *)skb->data + iphdroff; + + if (maniptype == NF_NAT_MANIP_SRC) { + csum_replace4(&iph->check, iph->saddr, target->src.u3.ip); + iph->saddr = target->src.u3.ip; + } else { + csum_replace4(&iph->check, iph->daddr, target->dst.u3.ip); + iph->daddr = target->dst.u3.ip; + } + return true; +} + +static bool nf_nat_ipv6_manip_pkt(struct sk_buff *skb, + unsigned int iphdroff, + const struct nf_conntrack_tuple *target, + enum nf_nat_manip_type maniptype) +{ +#if IS_ENABLED(CONFIG_IPV6) + 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 && + !nf_nat_l4proto_manip_pkt(skb, &nf_nat_l3proto_ipv6, iphdroff, hdroff, + target, maniptype)) + return false; + + /* must reload, offset might have changed */ + ipv6h = (void *)skb->data + iphdroff; + +manip_addr: + if (maniptype == NF_NAT_MANIP_SRC) + ipv6h->saddr = target->src.u3.in6; + else + ipv6h->daddr = target->dst.u3.in6; + +#endif + return true; +} + +static void nf_nat_ipv4_csum_update(struct sk_buff *skb, + unsigned int iphdroff, __sum16 *check, + const struct nf_conntrack_tuple *t, + enum nf_nat_manip_type maniptype) +{ + struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff); + __be32 oldip, newip; + + if (maniptype == NF_NAT_MANIP_SRC) { + oldip = iph->saddr; + newip = t->src.u3.ip; + } else { + oldip = iph->daddr; + newip = t->dst.u3.ip; + } + inet_proto_csum_replace4(check, skb, oldip, newip, 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) +{ +#if IS_ENABLED(CONFIG_IPV6) + 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, true); +#endif +} + +static void nf_nat_ipv4_csum_recalc(struct sk_buff *skb, + u8 proto, void *data, __sum16 *check, + int datalen, int oldlen) +{ + if (skb->ip_summed != CHECKSUM_PARTIAL) { + const struct iphdr *iph = ip_hdr(skb); + + skb->ip_summed = CHECKSUM_PARTIAL; + skb->csum_start = skb_headroom(skb) + skb_network_offset(skb) + + ip_hdrlen(skb); + skb->csum_offset = (void *)check - data; + *check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, datalen, + proto, 0); + } else { + inet_proto_csum_replace2(check, skb, + htons(oldlen), htons(datalen), true); + } +} + +#if IS_ENABLED(CONFIG_IPV6) +static void nf_nat_ipv6_csum_recalc(struct sk_buff *skb, + u8 proto, void *data, __sum16 *check, + int datalen, int oldlen) +{ + if (skb->ip_summed != CHECKSUM_PARTIAL) { + const struct ipv6hdr *ipv6h = ipv6_hdr(skb); + + 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 { + inet_proto_csum_replace2(check, skb, + htons(oldlen), htons(datalen), true); + } +} +#endif + +static const struct nf_nat_l3proto nf_nat_l3proto_ipv4 = { + .l3proto = NFPROTO_IPV4, + .manip_pkt = nf_nat_ipv4_manip_pkt, + .csum_update = nf_nat_ipv4_csum_update, + .csum_recalc = nf_nat_ipv4_csum_recalc, +}; + +int nf_nat_icmp_reply_translation(struct sk_buff *skb, + struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int hooknum) +{ + struct { + struct icmphdr icmp; + struct iphdr ip; + } *inside; + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + enum nf_nat_manip_type manip = HOOK2MANIP(hooknum); + unsigned int hdrlen = ip_hdrlen(skb); + struct nf_conntrack_tuple target; + unsigned long statusbit; + + WARN_ON(ctinfo != IP_CT_RELATED && ctinfo != IP_CT_RELATED_REPLY); + + if (!skb_make_writable(skb, hdrlen + sizeof(*inside))) + return 0; + if (nf_ip_checksum(skb, hooknum, hdrlen, 0)) + return 0; + + inside = (void *)skb->data + hdrlen; + if (inside->icmp.type == ICMP_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; + + if (!nf_nat_ipv4_manip_pkt(skb, hdrlen + sizeof(inside->icmp), + &ct->tuplehash[!dir].tuple, !manip)) + return 0; + + if (skb->ip_summed != CHECKSUM_PARTIAL) { + /* Reloading "inside" here since manip_pkt may reallocate */ + inside = (void *)skb->data + hdrlen; + inside->icmp.checksum = 0; + inside->icmp.checksum = + csum_fold(skb_checksum(skb, hdrlen, + skb->len - hdrlen, 0)); + } + + /* Change outer to look like the reply to an incoming packet */ + nf_ct_invert_tuple(&target, &ct->tuplehash[!dir].tuple); + target.dst.protonum = IPPROTO_ICMP; + if (!nf_nat_ipv4_manip_pkt(skb, 0, &target, manip)) + return 0; + + return 1; +} +EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation); + +static unsigned int +nf_nat_ipv4_fn(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + + ct = nf_ct_get(skb, &ctinfo); + if (!ct) + return NF_ACCEPT; + + if (ctinfo == IP_CT_RELATED || ctinfo == IP_CT_RELATED_REPLY) { + if (ip_hdr(skb)->protocol == IPPROTO_ICMP) { + if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo, + state->hook)) + return NF_DROP; + else + return NF_ACCEPT; + } + } + + return nf_nat_inet_fn(priv, skb, state); +} + +static unsigned int +nf_nat_ipv4_in(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + unsigned int ret; + __be32 daddr = ip_hdr(skb)->daddr; + + ret = nf_nat_ipv4_fn(priv, skb, state); + if (ret == NF_ACCEPT && daddr != ip_hdr(skb)->daddr) + skb_dst_drop(skb); + + return ret; +} + +static unsigned int +nf_nat_ipv4_out(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ +#ifdef CONFIG_XFRM + const struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + int err; +#endif + unsigned int ret; + + ret = nf_nat_ipv4_fn(priv, skb, state); +#ifdef CONFIG_XFRM + if (ret != NF_ACCEPT) + return ret; + + if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) + return ret; + + ct = nf_ct_get(skb, &ctinfo); + if (ct) { + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + + if (ct->tuplehash[dir].tuple.src.u3.ip != + ct->tuplehash[!dir].tuple.dst.u3.ip || + (ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP && + ct->tuplehash[dir].tuple.src.u.all != + ct->tuplehash[!dir].tuple.dst.u.all)) { + err = nf_xfrm_me_harder(state->net, skb, AF_INET); + if (err < 0) + ret = NF_DROP_ERR(err); + } + } +#endif + return ret; +} + +static unsigned int +nf_nat_ipv4_local_fn(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + const struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + unsigned int ret; + int err; + + ret = nf_nat_ipv4_fn(priv, skb, state); + if (ret != NF_ACCEPT) + return ret; + + ct = nf_ct_get(skb, &ctinfo); + if (ct) { + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + + if (ct->tuplehash[dir].tuple.dst.u3.ip != + ct->tuplehash[!dir].tuple.src.u3.ip) { + err = ip_route_me_harder(state->net, skb, RTN_UNSPEC); + if (err < 0) + ret = NF_DROP_ERR(err); + } +#ifdef CONFIG_XFRM + else if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && + ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP && + ct->tuplehash[dir].tuple.dst.u.all != + ct->tuplehash[!dir].tuple.src.u.all) { + err = nf_xfrm_me_harder(state->net, skb, AF_INET); + if (err < 0) + ret = NF_DROP_ERR(err); + } +#endif + } + return ret; +} + +static const struct nf_hook_ops nf_nat_ipv4_ops[] = { + /* Before packet filtering, change destination */ + { + .hook = nf_nat_ipv4_in, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_PRE_ROUTING, + .priority = NF_IP_PRI_NAT_DST, + }, + /* After packet filtering, change source */ + { + .hook = nf_nat_ipv4_out, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_POST_ROUTING, + .priority = NF_IP_PRI_NAT_SRC, + }, + /* Before packet filtering, change destination */ + { + .hook = nf_nat_ipv4_local_fn, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_NAT_DST, + }, + /* After packet filtering, change source */ + { + .hook = nf_nat_ipv4_fn, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_LOCAL_IN, + .priority = NF_IP_PRI_NAT_SRC, + }, +}; + +int nf_nat_l3proto_ipv4_register_fn(struct net *net, const struct nf_hook_ops *ops) +{ + return nf_nat_register_fn(net, ops, nf_nat_ipv4_ops, ARRAY_SIZE(nf_nat_ipv4_ops)); +} +EXPORT_SYMBOL_GPL(nf_nat_l3proto_ipv4_register_fn); + +void nf_nat_l3proto_ipv4_unregister_fn(struct net *net, const struct nf_hook_ops *ops) +{ + nf_nat_unregister_fn(net, ops, ARRAY_SIZE(nf_nat_ipv4_ops)); +} +EXPORT_SYMBOL_GPL(nf_nat_l3proto_ipv4_unregister_fn); + +int nf_nat_l3proto_init(void) +{ + int ret = nf_nat_l3proto_register(&nf_nat_l3proto_ipv4); + +#if IS_ENABLED(CONFIG_IPV6) + if (ret) + return ret; + + ret = nf_nat_l3proto_register(&nf_nat_l3proto_ipv6); + if (ret == 0) + return ret; + + nf_nat_l3proto_unregister(&nf_nat_l3proto_ipv4); +#endif + return ret; +} + +void nf_nat_l3proto_exit(void) +{ +#if IS_ENABLED(CONFIG_IPV6) + nf_nat_l3proto_unregister(&nf_nat_l3proto_ipv6); +#endif + nf_nat_l3proto_unregister(&nf_nat_l3proto_ipv4); +} + +#if IS_ENABLED(CONFIG_IPV6) +static const struct nf_nat_l3proto nf_nat_l3proto_ipv6; + +static const struct nf_nat_l3proto nf_nat_l3proto_ipv6 = { + .l3proto = NFPROTO_IPV6, + .manip_pkt = nf_nat_ipv6_manip_pkt, + .csum_update = nf_nat_ipv6_csum_update, + .csum_recalc = nf_nat_ipv6_csum_recalc, +}; + +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); + struct nf_conntrack_tuple target; + unsigned long statusbit; + + WARN_ON(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; + + if (!nf_nat_ipv6_manip_pkt(skb, hdrlen + sizeof(inside->icmp6), + &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, + skb_checksum(skb, hdrlen, + skb->len - hdrlen, 0)); + } + + nf_ct_invert_tuple(&target, &ct->tuplehash[!dir].tuple); + target.dst.protonum = IPPROTO_ICMPV6; + if (!nf_nat_ipv6_manip_pkt(skb, 0, &target, manip)) + return 0; + + return 1; +} +EXPORT_SYMBOL_GPL(nf_nat_icmpv6_reply_translation); + +static unsigned int +nf_nat_ipv6_fn(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + __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; + + if (ctinfo == IP_CT_RELATED || ctinfo == 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, + state->hook, + hdrlen)) + return NF_DROP; + else + return NF_ACCEPT; + } + } + + return nf_nat_inet_fn(priv, skb, state); +} + +static unsigned int +nf_nat_ipv6_in(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + unsigned int ret; + struct in6_addr daddr = ipv6_hdr(skb)->daddr; + + ret = nf_nat_ipv6_fn(priv, skb, state); + 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(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ +#ifdef CONFIG_XFRM + const struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + int err; +#endif + unsigned int ret; + + ret = nf_nat_ipv6_fn(priv, skb, state); +#ifdef CONFIG_XFRM + if (ret != NF_ACCEPT) + return ret; + + if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) + return ret; + ct = nf_ct_get(skb, &ctinfo); + if (ct) { + 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.dst.protonum != IPPROTO_ICMPV6 && + ct->tuplehash[dir].tuple.src.u.all != + ct->tuplehash[!dir].tuple.dst.u.all)) { + err = nf_xfrm_me_harder(state->net, skb, AF_INET6); + if (err < 0) + ret = NF_DROP_ERR(err); + } + } +#endif + + return ret; +} + +static int nat_route_me_harder(struct net *net, struct sk_buff *skb) +{ +#ifdef CONFIG_IPV6_MODULE + const struct nf_ipv6_ops *v6_ops = nf_get_ipv6_ops(); + + if (!v6_ops) + return -EHOSTUNREACH; + + return v6_ops->route_me_harder(net, skb); +#else + return ip6_route_me_harder(net, skb); +#endif +} + +static unsigned int +nf_nat_ipv6_local_fn(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + const struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + unsigned int ret; + int err; + + ret = nf_nat_ipv6_fn(priv, skb, state); + if (ret != NF_ACCEPT) + return ret; + + ct = nf_ct_get(skb, &ctinfo); + if (ct) { + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + + if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, + &ct->tuplehash[!dir].tuple.src.u3)) { + err = nat_route_me_harder(state->net, skb); + if (err < 0) + ret = NF_DROP_ERR(err); + } +#ifdef CONFIG_XFRM + else if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && + ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMPV6 && + ct->tuplehash[dir].tuple.dst.u.all != + ct->tuplehash[!dir].tuple.src.u.all) { + err = nf_xfrm_me_harder(state->net, skb, AF_INET6); + if (err < 0) + ret = NF_DROP_ERR(err); + } +#endif + } + + return ret; +} + +static const struct nf_hook_ops nf_nat_ipv6_ops[] = { + /* Before packet filtering, change destination */ + { + .hook = nf_nat_ipv6_in, + .pf = NFPROTO_IPV6, + .hooknum = NF_INET_PRE_ROUTING, + .priority = NF_IP6_PRI_NAT_DST, + }, + /* After packet filtering, change source */ + { + .hook = nf_nat_ipv6_out, + .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, + .pf = NFPROTO_IPV6, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP6_PRI_NAT_DST, + }, + /* After packet filtering, change source */ + { + .hook = nf_nat_ipv6_fn, + .pf = NFPROTO_IPV6, + .hooknum = NF_INET_LOCAL_IN, + .priority = NF_IP6_PRI_NAT_SRC, + }, +}; + +int nf_nat_l3proto_ipv6_register_fn(struct net *net, const struct nf_hook_ops *ops) +{ + return nf_nat_register_fn(net, ops, nf_nat_ipv6_ops, + ARRAY_SIZE(nf_nat_ipv6_ops)); +} +EXPORT_SYMBOL_GPL(nf_nat_l3proto_ipv6_register_fn); + +void nf_nat_l3proto_ipv6_unregister_fn(struct net *net, const struct nf_hook_ops *ops) +{ + nf_nat_unregister_fn(net, ops, ARRAY_SIZE(nf_nat_ipv6_ops)); +} +EXPORT_SYMBOL_GPL(nf_nat_l3proto_ipv6_unregister_fn); +#endif /* CONFIG_IPV6 */ |