/* * (C) 1999-2001 Paul `Rusty' Russell * (C) 2002-2006 Netfilter Core Team * (C) 2011 Patrick McHardy * * 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static DEFINE_SPINLOCK(nf_nat_lock); static DEFINE_MUTEX(nf_nat_proto_mutex); static const struct nf_nat_l3proto __rcu *nf_nat_l3protos[NFPROTO_NUMPROTO] __read_mostly; static const struct nf_nat_l4proto __rcu **nf_nat_l4protos[NFPROTO_NUMPROTO] __read_mostly; inline const struct nf_nat_l3proto * __nf_nat_l3proto_find(u8 family) { return rcu_dereference(nf_nat_l3protos[family]); } inline const struct nf_nat_l4proto * __nf_nat_l4proto_find(u8 family, u8 protonum) { return rcu_dereference(nf_nat_l4protos[family][protonum]); } EXPORT_SYMBOL_GPL(__nf_nat_l4proto_find); #ifdef CONFIG_XFRM static void __nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl) { const struct nf_nat_l3proto *l3proto; const struct nf_conn *ct; enum ip_conntrack_info ctinfo; enum ip_conntrack_dir dir; unsigned long statusbit; u8 family; ct = nf_ct_get(skb, &ctinfo); if (ct == NULL) return; family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num; rcu_read_lock(); l3proto = __nf_nat_l3proto_find(family); if (l3proto == NULL) goto out; dir = CTINFO2DIR(ctinfo); if (dir == IP_CT_DIR_ORIGINAL) statusbit = IPS_DST_NAT; else statusbit = IPS_SRC_NAT; l3proto->decode_session(skb, ct, dir, statusbit, fl); out: rcu_read_unlock(); } int nf_xfrm_me_harder(struct sk_buff *skb, unsigned int family) { struct flowi fl; unsigned int hh_len; struct dst_entry *dst; if (xfrm_decode_session(skb, &fl, family) < 0) return -1; dst = skb_dst(skb); if (dst->xfrm) dst = ((struct xfrm_dst *)dst)->route; dst_hold(dst); dst = xfrm_lookup(dev_net(dst->dev), dst, &fl, skb->sk, 0); if (IS_ERR(dst)) return -1; skb_dst_drop(skb); skb_dst_set(skb, dst); /* Change in oif may mean change in hh_len. */ hh_len = skb_dst(skb)->dev->hard_header_len; if (skb_headroom(skb) < hh_len && pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC)) return -1; return 0; } EXPORT_SYMBOL(nf_xfrm_me_harder); #endif /* CONFIG_XFRM */ /* We keep an extra hash for each conntrack, for fast searching. */ static inline unsigned int hash_by_src(const struct net *net, u16 zone, const struct nf_conntrack_tuple *tuple) { unsigned int hash; /* Original src, to ensure we map it consistently if poss. */ hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32), tuple->dst.protonum ^ zone ^ nf_conntrack_hash_rnd); return ((u64)hash * net->ct.nat_htable_size) >> 32; } /* Is this tuple already taken? (not by us) */ int nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple, const struct nf_conn *ignored_conntrack) { /* Conntrack tracking doesn't keep track of outgoing tuples; only * incoming ones. NAT means they don't have a fixed mapping, * so we invert the tuple and look for the incoming reply. * * We could keep a separate hash if this proves too slow. */ struct nf_conntrack_tuple reply; nf_ct_invert_tuplepr(&reply, tuple); return nf_conntrack_tuple_taken(&reply, ignored_conntrack); } EXPORT_SYMBOL(nf_nat_used_tuple); /* If we source map this tuple so reply looks like reply_tuple, will * that meet the constraints of range. */ static int in_range(const struct nf_nat_l3proto *l3proto, const struct nf_nat_l4proto *l4proto, const struct nf_conntrack_tuple *tuple, const struct nf_nat_range *range) { /* If we are supposed to map IPs, then we must be in the * range specified, otherwise let this drag us onto a new src IP. */ if (range->flags & NF_NAT_RANGE_MAP_IPS && !l3proto->in_range(tuple, range)) return 0; if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) || l4proto->in_range(tuple, NF_NAT_MANIP_SRC, &range->min_proto, &range->max_proto)) return 1; return 0; } static inline int same_src(const struct nf_conn *ct, const struct nf_conntrack_tuple *tuple) { const struct nf_conntrack_tuple *t; t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; return (t->dst.protonum == tuple->dst.protonum && nf_inet_addr_cmp(&t->src.u3, &tuple->src.u3) && t->src.u.all == tuple->src.u.all); } /* Only called for SRC manip */ static int find_appropriate_src(struct net *net, u16 zone, const struct nf_nat_l3proto *l3proto, const struct nf_nat_l4proto *l4proto, const struct nf_conntrack_tuple *tuple, struct nf_conntrack_tuple *result, const struct nf_nat_range *range) { unsigned int h = hash_by_src(net, zone, tuple); const struct nf_conn_nat *nat; const struct nf_conn *ct; hlist_for_each_entry_rcu(nat, &net->ct.nat_bysource[h], bysource) { ct = nat->ct; if (same_src(ct, tuple) && nf_ct_zone(ct) == zone) { /* Copy source part from reply tuple. */ nf_ct_invert_tuplepr(result, &ct->tuplehash[IP_CT_DIR_REPLY].tuple); result->dst = tuple->dst; if (in_range(l3proto, l4proto, result, range)) return 1; } } return 0; } /* For [FUTURE] fragmentation handling, we want the least-used * src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus * if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports * 1-65535, we don't do pro-rata allocation based on ports; we choose * the ip with the lowest src-ip/dst-ip/proto usage. */ static void find_best_ips_proto(u16 zone, struct nf_conntrack_tuple *tuple, const struct nf_nat_range *range, const struct nf_conn *ct, enum nf_nat_manip_type maniptype) { union nf_inet_addr *var_ipp; unsigned int i, max; /* Host order */ u32 minip, maxip, j, dist; bool full_range; /* No IP mapping? Do nothing. */ if (!(range->flags & NF_NAT_RANGE_MAP_IPS)) return; if (maniptype == NF_NAT_MANIP_SRC) var_ipp = &tuple->src.u3; else var_ipp = &tuple->dst.u3; /* Fast path: only one choice. */ if (nf_inet_addr_cmp(&range->min_addr, &range->max_addr)) { *var_ipp = range->min_addr; return; } if (nf_ct_l3num(ct) == NFPROTO_IPV4) max = sizeof(var_ipp->ip) / sizeof(u32) - 1; else max = sizeof(var_ipp->ip6) / sizeof(u32) - 1; /* Hashing source and destination IPs gives a fairly even * spread in practice (if there are a small number of IPs * involved, there usually aren't that many connections * anyway). The consistency means that servers see the same * client coming from the same IP (some Internet Banking sites * like this), even across reboots. */ j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3) / sizeof(u32), range->flags & NF_NAT_RANGE_PERSISTENT ? 0 : (__force u32)tuple->dst.u3.all[max] ^ zone); full_range = false; for (i = 0; i <= max; i++) { /* If first bytes of the address are at the maximum, use the * distance. Otherwise use the full range. */ if (!full_range) { minip = ntohl((__force __be32)range->min_addr.all[i]); maxip = ntohl((__force __be32)range->max_addr.all[i]); dist = maxip - minip + 1; } else { minip = 0; dist = ~0; } var_ipp->all[i] = (__force __u32) htonl(minip + (((u64)j * dist) >> 32)); if (var_ipp->all[i] != range->max_addr.all[i]) full_range = true; if (!(range->flags & NF_NAT_RANGE_PERSISTENT)) j ^= (__force u32)tuple->dst.u3.all[i]; } } /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING, * we change the source to map into the range. For NF_INET_PRE_ROUTING * and NF_INET_LOCAL_OUT, we change the destination to map into the * range. It might not be possible to get a unique tuple, but we try. * At worst (or if we race), we will end up with a final duplicate in * __ip_conntrack_confirm and drop the packet. */ static void get_unique_tuple(struct nf_conntrack_tuple *tuple, const struct nf_conntrack_tuple *orig_tuple, const struct nf_nat_range *range, struct nf_conn *ct, enum nf_nat_manip_type maniptype) { const struct nf_nat_l3proto *l3proto; const struct nf_nat_l4proto *l4proto; struct net *net = nf_ct_net(ct); u16 zone = nf_ct_zone(ct); rcu_read_lock(); l3proto = __nf_nat_l3proto_find(orig_tuple->src.l3num); l4proto = __nf_nat_l4proto_find(orig_tuple->src.l3num, orig_tuple->dst.protonum); /* 1) If this srcip/proto/src-proto-part is currently mapped, * and that same mapping gives a unique tuple within the given * range, use that. * * This is only required for source (ie. NAT/masq) mappings. * So far, we don't do local source mappings, so multiple * manips not an issue. */ if (maniptype == NF_NAT_MANIP_SRC && !(range->flags & NF_NAT_RANGE_PROTO_RANDOM)) { /* try the original tuple first */ if (in_range(l3proto, l4proto, orig_tuple, range)) { if (!nf_nat_used_tuple(orig_tuple, ct)) { *tuple = *orig_tuple; goto out; } } else if (find_appropriate_src(net, zone, l3proto, l4proto, orig_tuple, tuple, range)) { pr_debug("get_unique_tuple: Found current src map\n"); if (!nf_nat_used_tuple(tuple, ct)) goto out; } } /* 2) Select the least-used IP/proto combination in the given range */ *tuple = *orig_tuple; find_best_ips_proto(zone, tuple, range, ct, maniptype); /* 3) The per-protocol part of the manip is made to map into * the range to make a unique tuple. */ /* Only bother mapping if it's not already in range and unique */ if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM)) { if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) { if (l4proto->in_range(tuple, maniptype, &range->min_proto, &range->max_proto) && (range->min_proto.all == range->max_proto.all || !nf_nat_used_tuple(tuple, ct))) goto out; } else if (!nf_nat_used_tuple(tuple, ct)) { goto out; } } /* Last change: get protocol to try to obtain unique tuple. */ l4proto->unique_tuple(l3proto, tuple, range, maniptype, ct); out: rcu_read_unlock(); } unsigned int nf_nat_setup_info(struct nf_conn *ct, const struct nf_nat_range *range, enum nf_nat_manip_type maniptype) { struct net *net = nf_ct_net(ct); struct nf_conntrack_tuple curr_tuple, new_tuple; struct nf_conn_nat *nat; /* nat helper or nfctnetlink also setup binding */ nat = nfct_nat(ct); if (!nat) { 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; } } NF_CT_ASSERT(maniptype == NF_NAT_MANIP_SRC || maniptype == NF_NAT_MANIP_DST); BUG_ON(nf_nat_initialized(ct, maniptype)); /* What we've got will look like inverse of reply. Normally * this is what is in the conntrack, except for prior * manipulations (future optimization: if num_manips == 0, * orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple) */ nf_ct_invert_tuplepr(&curr_tuple, &ct->tuplehash[IP_CT_DIR_REPLY].tuple); get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype); if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) { struct nf_conntrack_tuple reply; /* Alter conntrack table so will recognize replies. */ nf_ct_invert_tuplepr(&reply, &new_tuple); nf_conntrack_alter_reply(ct, &reply); /* Non-atomic: we own this at the moment. */ if (maniptype == NF_NAT_MANIP_SRC) ct->status |= IPS_SRC_NAT; else ct->status |= IPS_DST_NAT; } if (maniptype == NF_NAT_MANIP_SRC) { unsigned int srchash; srchash = hash_by_src(net, nf_ct_zone(ct), &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); spin_lock_bh(&nf_nat_lock); /* nf_conntrack_alter_reply might re-allocate extension aera */ nat = nfct_nat(ct); nat->ct = ct; hlist_add_head_rcu(&nat->bysource, &net->ct.nat_bysource[srchash]); spin_unlock_bh(&nf_nat_lock); } /* It's done. */ if (maniptype == NF_NAT_MANIP_DST) ct->status |= IPS_DST_NAT_DONE; else ct->status |= IPS_SRC_NAT_DONE; return NF_ACCEPT; } EXPORT_SYMBOL(nf_nat_setup_info); /* Do packet manipulations according to nf_nat_setup_info. */ unsigned int nf_nat_packet(struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned int hooknum, struct sk_buff *skb) { const struct nf_nat_l3proto *l3proto; const struct nf_nat_l4proto *l4proto; enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); unsigned long statusbit; enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum); if (mtype == NF_NAT_MANIP_SRC) statusbit = IPS_SRC_NAT; else statusbit = IPS_DST_NAT; /* Invert if this is reply dir. */ if (dir == IP_CT_DIR_REPLY) statusbit ^= IPS_NAT_MASK; /* Non-atomic: these bits don't change. */ if (ct->status & statusbit) { struct nf_conntrack_tuple target; /* We are aiming to look like inverse of other direction. */ nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); l3proto = __nf_nat_l3proto_find(target.src.l3num); l4proto = __nf_nat_l4proto_find(target.src.l3num, target.dst.protonum); if (!l3proto->manip_pkt(skb, 0, l4proto, &target, mtype)) return NF_DROP; } return NF_ACCEPT; } EXPORT_SYMBOL_GPL(nf_nat_packet); struct nf_nat_proto_clean { u8 l3proto; u8 l4proto; bool hash; }; /* Clear NAT section of all conntracks, in case we're loaded again. */ static int nf_nat_proto_clean(struct nf_conn *i, void *data) { const struct nf_nat_proto_clean *clean = data; struct nf_conn_nat *nat = nfct_nat(i); if (!nat) return 0; if (!(i->status & IPS_SRC_NAT_DONE)) return 0; if ((clean->l3proto && nf_ct_l3num(i) != clean->l3proto) || (clean->l4proto && nf_ct_protonum(i) != clean->l4proto)) return 0; if (clean->hash) { spin_lock_bh(&nf_nat_lock); hlist_del_rcu(&nat->bysource); spin_unlock_bh(&nf_nat_lock); } else { memset(nat, 0, sizeof(*nat)); i->status &= ~(IPS_NAT_MASK | IPS_NAT_DONE_MASK | IPS_SEQ_ADJUST); } return 0; } static void nf_nat_l4proto_clean(u8 l3proto, u8 l4proto) { struct nf_nat_proto_clean clean = { .l3proto = l3proto, .l4proto = l4proto, }; struct net *net; rtnl_lock(); /* Step 1 - remove from bysource hash */ clean.hash = true; for_each_net(net) nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean); synchronize_rcu(); /* Step 2 - clean NAT section */ clean.hash = false; for_each_net(net) nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean); rtnl_unlock(); } static void nf_nat_l3proto_clean(u8 l3proto) { struct nf_nat_proto_clean clean = { .l3proto = l3proto, }; struct net *net; rtnl_lock(); /* Step 1 - remove from bysource hash */ clean.hash = true; for_each_net(net) nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean); synchronize_rcu(); /* Step 2 - clean NAT section */ clean.hash = false; for_each_net(net) nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean); rtnl_unlock(); } /* Protocol registration. */ int nf_nat_l4proto_register(u8 l3proto, const struct nf_nat_l4proto *l4proto) { const struct nf_nat_l4proto **l4protos; unsigned int i; int ret = 0; mutex_lock(&nf_nat_proto_mutex); if (nf_nat_l4protos[l3proto] == NULL) { l4protos = kmalloc(IPPROTO_MAX * sizeof(struct nf_nat_l4proto *), GFP_KERNEL); if (l4protos == NULL) { ret = -ENOMEM; goto out; } for (i = 0; i < IPPROTO_MAX; i++) RCU_INIT_POINTER(l4protos[i], &nf_nat_l4proto_unknown); /* Before making proto_array visible to lockless readers, * we must make sure its content is committed to memory. */ smp_wmb(); nf_nat_l4protos[l3proto] = l4protos; } if (rcu_dereference_protected( nf_nat_l4protos[l3proto][l4proto->l4proto], lockdep_is_held(&nf_nat_proto_mutex) ) != &nf_nat_l4proto_unknown) { ret = -EBUSY; goto out; } RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto], l4proto); out: mutex_unlock(&nf_nat_proto_mutex); return ret; } EXPORT_SYMBOL_GPL(nf_nat_l4proto_register); /* No one stores the protocol anywhere; simply delete it. */ void nf_nat_l4proto_unregister(u8 l3proto, const struct nf_nat_l4proto *l4proto) { mutex_lock(&nf_nat_proto_mutex); RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto], &nf_nat_l4proto_unknown); mutex_unlock(&nf_nat_proto_mutex); synchronize_rcu(); nf_nat_l4proto_clean(l3proto, l4proto->l4proto); } EXPORT_SYMBOL_GPL(nf_nat_l4proto_unregister); int nf_nat_l3proto_register(const struct nf_nat_l3proto *l3proto) { int err; err = nf_ct_l3proto_try_module_get(l3proto->l3proto); if (err < 0) return err; mutex_lock(&nf_nat_proto_mutex); RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_TCP], &nf_nat_l4proto_tcp); RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_UDP], &nf_nat_l4proto_udp); mutex_unlock(&nf_nat_proto_mutex); RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], l3proto); return 0; } EXPORT_SYMBOL_GPL(nf_nat_l3proto_register); void nf_nat_l3proto_unregister(const struct nf_nat_l3proto *l3proto) { mutex_lock(&nf_nat_proto_mutex); RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], NULL); mutex_unlock(&nf_nat_proto_mutex); synchronize_rcu(); nf_nat_l3proto_clean(l3proto->l3proto); nf_ct_l3proto_module_put(l3proto->l3proto); } EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister); /* No one using conntrack by the time this called. */ static void nf_nat_cleanup_conntrack(struct nf_conn *ct) { struct nf_conn_nat *nat = nf_ct_ext_find(ct, NF_CT_EXT_NAT); if (nat == NULL || nat->ct == NULL) return; NF_CT_ASSERT(nat->ct->status & IPS_SRC_NAT_DONE); spin_lock_bh(&nf_nat_lock); hlist_del_rcu(&nat->bysource); spin_unlock_bh(&nf_nat_lock); } static void nf_nat_move_storage(void *new, void *old) { struct nf_conn_nat *new_nat = new; struct nf_conn_nat *old_nat = old; struct nf_conn *ct = old_nat->ct; if (!ct || !(ct->status & IPS_SRC_NAT_DONE)) return; spin_lock_bh(&nf_nat_lock); hlist_replace_rcu(&old_nat->bysource, &new_nat->bysource); spin_unlock_bh(&nf_nat_lock); } static struct nf_ct_ext_type nat_extend __read_mostly = { .len = sizeof(struct nf_conn_nat), .align = __alignof__(struct nf_conn_nat), .destroy = nf_nat_cleanup_conntrack, .move = nf_nat_move_storage, .id = NF_CT_EXT_NAT, .flags = NF_CT_EXT_F_PREALLOC, }; #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) #include #include static const struct nla_policy protonat_nla_policy[CTA_PROTONAT_MAX+1] = { [CTA_PROTONAT_PORT_MIN] = { .type = NLA_U16 }, [CTA_PROTONAT_PORT_MAX] = { .type = NLA_U16 }, }; static int nfnetlink_parse_nat_proto(struct nlattr *attr, const struct nf_conn *ct, struct nf_nat_range *range) { struct nlattr *tb[CTA_PROTONAT_MAX+1]; const struct nf_nat_l4proto *l4proto; int err; err = nla_parse_nested(tb, CTA_PROTONAT_MAX, attr, protonat_nla_policy); if (err < 0) return err; l4proto = __nf_nat_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct)); if (l4proto->nlattr_to_range) err = l4proto->nlattr_to_range(tb, range); return err; } static const struct nla_policy nat_nla_policy[CTA_NAT_MAX+1] = { [CTA_NAT_V4_MINIP] = { .type = NLA_U32 }, [CTA_NAT_V4_MAXIP] = { .type = NLA_U32 }, [CTA_NAT_V6_MINIP] = { .len = sizeof(struct in6_addr) }, [CTA_NAT_V6_MAXIP] = { .len = sizeof(struct in6_addr) }, [CTA_NAT_PROTO] = { .type = NLA_NESTED }, }; static int nfnetlink_parse_nat(const struct nlattr *nat, const struct nf_conn *ct, struct nf_nat_range *range) { const struct nf_nat_l3proto *l3proto; struct nlattr *tb[CTA_NAT_MAX+1]; int err; memset(range, 0, sizeof(*range)); err = nla_parse_nested(tb, CTA_NAT_MAX, nat, nat_nla_policy); if (err < 0) return err; rcu_read_lock(); l3proto = __nf_nat_l3proto_find(nf_ct_l3num(ct)); if (l3proto == NULL) { err = -EAGAIN; goto out; } err = l3proto->nlattr_to_range(tb, range); if (err < 0) goto out; if (!tb[CTA_NAT_PROTO]) goto out; err = nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO], ct, range); out: rcu_read_unlock(); return err; } static int nfnetlink_parse_nat_setup(struct nf_conn *ct, enum nf_nat_manip_type manip, const struct nlattr *attr) { struct nf_nat_range range; int err; err = nfnetlink_parse_nat(attr, ct, &range); if (err < 0) return err; if (nf_nat_initialized(ct, manip)) return -EEXIST; return nf_nat_setup_info(ct, &range, manip); } #else static int nfnetlink_parse_nat_setup(struct nf_conn *ct, enum nf_nat_manip_type manip, const struct nlattr *attr) { return -EOPNOTSUPP; } #endif static int __net_init nf_nat_net_init(struct net *net) { /* Leave them the same for the moment. */ net->ct.nat_htable_size = net->ct.htable_size; net->ct.nat_bysource = nf_ct_alloc_hashtable(&net->ct.nat_htable_size, 0); if (!net->ct.nat_bysource) return -ENOMEM; return 0; } static void __net_exit nf_nat_net_exit(struct net *net) { struct nf_nat_proto_clean clean = {}; nf_ct_iterate_cleanup(net, &nf_nat_proto_clean, &clean); synchronize_rcu(); nf_ct_free_hashtable(net->ct.nat_bysource, net->ct.nat_htable_size); } static struct pernet_operations nf_nat_net_ops = { .init = nf_nat_net_init, .exit = nf_nat_net_exit, }; static struct nf_ct_helper_expectfn follow_master_nat = { .name = "nat-follow-master", .expectfn = nf_nat_follow_master, }; static struct nfq_ct_nat_hook nfq_ct_nat = { .seq_adjust = nf_nat_tcp_seq_adjust, }; static int __init nf_nat_init(void) { int ret; ret = nf_ct_extend_register(&nat_extend); if (ret < 0) { printk(KERN_ERR "nf_nat_core: Unable to register extension\n"); return ret; } ret = register_pernet_subsys(&nf_nat_net_ops); if (ret < 0) goto cleanup_extend; nf_ct_helper_expectfn_register(&follow_master_nat); /* Initialize fake conntrack so that NAT will skip it */ nf_ct_untracked_status_or(IPS_NAT_DONE_MASK); BUG_ON(nf_nat_seq_adjust_hook != NULL); RCU_INIT_POINTER(nf_nat_seq_adjust_hook, nf_nat_seq_adjust); BUG_ON(nfnetlink_parse_nat_setup_hook != NULL); RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook, nfnetlink_parse_nat_setup); BUG_ON(nf_ct_nat_offset != NULL); RCU_INIT_POINTER(nf_ct_nat_offset, nf_nat_get_offset); RCU_INIT_POINTER(nfq_ct_nat_hook, &nfq_ct_nat); #ifdef CONFIG_XFRM BUG_ON(nf_nat_decode_session_hook != NULL); RCU_INIT_POINTER(nf_nat_decode_session_hook, __nf_nat_decode_session); #endif return 0; cleanup_extend: nf_ct_extend_unregister(&nat_extend); return ret; } static void __exit nf_nat_cleanup(void) { unsigned int i; unregister_pernet_subsys(&nf_nat_net_ops); nf_ct_extend_unregister(&nat_extend); nf_ct_helper_expectfn_unregister(&follow_master_nat); RCU_INIT_POINTER(nf_nat_seq_adjust_hook, NULL); RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook, NULL); RCU_INIT_POINTER(nf_ct_nat_offset, NULL); RCU_INIT_POINTER(nfq_ct_nat_hook, NULL); #ifdef CONFIG_XFRM RCU_INIT_POINTER(nf_nat_decode_session_hook, NULL); #endif for (i = 0; i < NFPROTO_NUMPROTO; i++) kfree(nf_nat_l4protos[i]); synchronize_net(); } MODULE_LICENSE("GPL"); module_init(nf_nat_init); module_exit(nf_nat_cleanup);