From c7232c9979cba684c50b64c513c4a83c9aa70563 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Sun, 26 Aug 2012 19:14:06 +0200 Subject: netfilter: add protocol independent NAT core Convert the IPv4 NAT implementation to a protocol independent core and address family specific modules. Signed-off-by: Patrick McHardy --- net/ipv4/netfilter/nf_nat_core.c | 763 --------------------------------------- 1 file changed, 763 deletions(-) delete mode 100644 net/ipv4/netfilter/nf_nat_core.c (limited to 'net/ipv4/netfilter/nf_nat_core.c') diff --git a/net/ipv4/netfilter/nf_nat_core.c b/net/ipv4/netfilter/nf_nat_core.c deleted file mode 100644 index 44b082fd48ab..000000000000 --- a/net/ipv4/netfilter/nf_nat_core.c +++ /dev/null @@ -1,763 +0,0 @@ -/* NAT for netfilter; shared with compatibility layer. */ - -/* (C) 1999-2001 Paul `Rusty' Russell - * (C) 2002-2006 Netfilter Core Team - * - * 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 /* For tcp_prot in getorigdst */ -#include -#include -#include - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -static DEFINE_SPINLOCK(nf_nat_lock); - -static struct nf_conntrack_l3proto *l3proto __read_mostly; - -#define MAX_IP_NAT_PROTO 256 -static const struct nf_nat_protocol __rcu *nf_nat_protos[MAX_IP_NAT_PROTO] - __read_mostly; - -static inline const struct nf_nat_protocol * -__nf_nat_proto_find(u_int8_t protonum) -{ - return rcu_dereference(nf_nat_protos[protonum]); -} - -/* 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 = jhash_3words((__force u32)tuple->src.u3.ip, - (__force u32)tuple->src.u.all ^ zone, - tuple->dst.protonum, nf_conntrack_hash_rnd); - return ((u64)hash * net->ipv4.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_conntrack_tuple *tuple, - const struct nf_nat_ipv4_range *range) -{ - const struct nf_nat_protocol *proto; - int ret = 0; - - /* 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) { - if (ntohl(tuple->src.u3.ip) < ntohl(range->min_ip) || - ntohl(tuple->src.u3.ip) > ntohl(range->max_ip)) - return 0; - } - - rcu_read_lock(); - proto = __nf_nat_proto_find(tuple->dst.protonum); - if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) || - proto->in_range(tuple, NF_NAT_MANIP_SRC, - &range->min, &range->max)) - ret = 1; - rcu_read_unlock(); - - return ret; -} - -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 && - t->src.u3.ip == tuple->src.u3.ip && - 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_conntrack_tuple *tuple, - struct nf_conntrack_tuple *result, - const struct nf_nat_ipv4_range *range) -{ - unsigned int h = hash_by_src(net, zone, tuple); - const struct nf_conn_nat *nat; - const struct nf_conn *ct; - const struct hlist_node *n; - - rcu_read_lock(); - hlist_for_each_entry_rcu(nat, n, &net->ipv4.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(result, range)) { - rcu_read_unlock(); - return 1; - } - } - } - rcu_read_unlock(); - 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_ipv4_range *range, - const struct nf_conn *ct, - enum nf_nat_manip_type maniptype) -{ - __be32 *var_ipp; - /* Host order */ - u_int32_t minip, maxip, j; - - /* 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.ip; - else - var_ipp = &tuple->dst.u3.ip; - - /* Fast path: only one choice. */ - if (range->min_ip == range->max_ip) { - *var_ipp = range->min_ip; - return; - } - - /* 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. */ - minip = ntohl(range->min_ip); - maxip = ntohl(range->max_ip); - j = jhash_2words((__force u32)tuple->src.u3.ip, - range->flags & NF_NAT_RANGE_PERSISTENT ? - 0 : (__force u32)tuple->dst.u3.ip ^ zone, 0); - j = ((u64)j * (maxip - minip + 1)) >> 32; - *var_ipp = htonl(minip + j); -} - -/* 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_ipv4_range *range, - struct nf_conn *ct, - enum nf_nat_manip_type maniptype) -{ - struct net *net = nf_ct_net(ct); - const struct nf_nat_protocol *proto; - u16 zone = nf_ct_zone(ct); - - /* 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(orig_tuple, range)) { - if (!nf_nat_used_tuple(orig_tuple, ct)) { - *tuple = *orig_tuple; - return; - } - } else if (find_appropriate_src(net, zone, orig_tuple, tuple, - range)) { - pr_debug("get_unique_tuple: Found current src map\n"); - if (!nf_nat_used_tuple(tuple, ct)) - return; - } - } - - /* 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. */ - - rcu_read_lock(); - proto = __nf_nat_proto_find(orig_tuple->dst.protonum); - - /* 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 (proto->in_range(tuple, maniptype, &range->min, - &range->max) && - (range->min.all == range->max.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. */ - proto->unique_tuple(tuple, range, maniptype, ct); -out: - rcu_read_unlock(); -} - -unsigned int -nf_nat_setup_info(struct nf_conn *ct, - const struct nf_nat_ipv4_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 = - conntrack->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 area */ - nat = nfct_nat(ct); - nat->ct = ct; - hlist_add_head_rcu(&nat->bysource, - &net->ipv4.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); - -/* Returns true if succeeded. */ -static bool -manip_pkt(u_int16_t proto, - struct sk_buff *skb, - unsigned int iphdroff, - const struct nf_conntrack_tuple *target, - enum nf_nat_manip_type maniptype) -{ - struct iphdr *iph; - const struct nf_nat_protocol *p; - - if (!skb_make_writable(skb, iphdroff + sizeof(*iph))) - return false; - - iph = (void *)skb->data + iphdroff; - - /* Manipulate protcol part. */ - - /* rcu_read_lock()ed by nf_hook_slow */ - p = __nf_nat_proto_find(proto); - if (!p->manip_pkt(skb, iphdroff, 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; -} - -/* 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) -{ - 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); - - if (!manip_pkt(target.dst.protonum, skb, 0, &target, mtype)) - return NF_DROP; - } - return NF_ACCEPT; -} -EXPORT_SYMBOL_GPL(nf_nat_packet); - -/* Dir is direction ICMP is coming from (opposite to packet it contains) */ -int nf_nat_icmp_reply_translation(struct nf_conn *ct, - enum ip_conntrack_info ctinfo, - unsigned int hooknum, - struct sk_buff *skb) -{ - struct { - struct icmphdr icmp; - struct iphdr ip; - } *inside; - struct nf_conntrack_tuple target; - int hdrlen = ip_hdrlen(skb); - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - unsigned long statusbit; - enum nf_nat_manip_type manip = HOOK2MANIP(hooknum); - - if (!skb_make_writable(skb, hdrlen + sizeof(*inside))) - return 0; - - inside = (void *)skb->data + hdrlen; - - /* We're actually going to mangle it beyond trivial checksum - adjustment, so make sure the current checksum is correct. */ - if (nf_ip_checksum(skb, hooknum, hdrlen, 0)) - return 0; - - /* Must be RELATED */ - NF_CT_ASSERT(skb->nfctinfo == IP_CT_RELATED || - skb->nfctinfo == IP_CT_RELATED_REPLY); - - /* Redirects on non-null nats must be dropped, else they'll - start talking to each other without our translation, and be - confused... --RR */ - if (inside->icmp.type == ICMP_REDIRECT) { - /* If NAT isn't finished, assume it and drop. */ - 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 dir. */ - if (dir == IP_CT_DIR_REPLY) - statusbit ^= IPS_NAT_MASK; - - if (!(ct->status & statusbit)) - return 1; - - pr_debug("icmp_reply_translation: translating error %p manip %u " - "dir %s\n", skb, manip, - dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY"); - - /* Change inner back to look like incoming packet. We do the - opposite manip on this hook to normal, because it might not - pass all hooks (locally-generated ICMP). Consider incoming - packet: PREROUTING (DST manip), routing produces ICMP, goes - through POSTROUTING (which must correct the DST manip). */ - if (!manip_pkt(inside->ip.protocol, skb, hdrlen + sizeof(inside->icmp), - &ct->tuplehash[!dir].tuple, !manip)) - return 0; - - if (skb->ip_summed != CHECKSUM_PARTIAL) { - /* Reloading "inside" here since manip_pkt inner. */ - 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 the reply to an incoming packet - * (proto 0 means don't invert per-proto part). */ - nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); - if (!manip_pkt(0, skb, 0, &target, manip)) - return 0; - - return 1; -} -EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation); - -/* Protocol registration. */ -int nf_nat_protocol_register(const struct nf_nat_protocol *proto) -{ - int ret = 0; - - spin_lock_bh(&nf_nat_lock); - if (rcu_dereference_protected( - nf_nat_protos[proto->protonum], - lockdep_is_held(&nf_nat_lock) - ) != &nf_nat_unknown_protocol) { - ret = -EBUSY; - goto out; - } - RCU_INIT_POINTER(nf_nat_protos[proto->protonum], proto); - out: - spin_unlock_bh(&nf_nat_lock); - return ret; -} -EXPORT_SYMBOL(nf_nat_protocol_register); - -/* No one stores the protocol anywhere; simply delete it. */ -void nf_nat_protocol_unregister(const struct nf_nat_protocol *proto) -{ - spin_lock_bh(&nf_nat_lock); - RCU_INIT_POINTER(nf_nat_protos[proto->protonum], - &nf_nat_unknown_protocol); - spin_unlock_bh(&nf_nat_lock); - synchronize_rcu(); -} -EXPORT_SYMBOL(nf_nat_protocol_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_ipv4_range *range) -{ - struct nlattr *tb[CTA_PROTONAT_MAX+1]; - const struct nf_nat_protocol *npt; - int err; - - err = nla_parse_nested(tb, CTA_PROTONAT_MAX, attr, protonat_nla_policy); - if (err < 0) - return err; - - rcu_read_lock(); - npt = __nf_nat_proto_find(nf_ct_protonum(ct)); - if (npt->nlattr_to_range) - err = npt->nlattr_to_range(tb, range); - rcu_read_unlock(); - return err; -} - -static const struct nla_policy nat_nla_policy[CTA_NAT_MAX+1] = { - [CTA_NAT_MINIP] = { .type = NLA_U32 }, - [CTA_NAT_MAXIP] = { .type = NLA_U32 }, - [CTA_NAT_PROTO] = { .type = NLA_NESTED }, -}; - -static int -nfnetlink_parse_nat(const struct nlattr *nat, - const struct nf_conn *ct, struct nf_nat_ipv4_range *range) -{ - 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; - - if (tb[CTA_NAT_MINIP]) - range->min_ip = nla_get_be32(tb[CTA_NAT_MINIP]); - - if (!tb[CTA_NAT_MAXIP]) - range->max_ip = range->min_ip; - else - range->max_ip = nla_get_be32(tb[CTA_NAT_MAXIP]); - - if (range->min_ip) - range->flags |= NF_NAT_RANGE_MAP_IPS; - - if (!tb[CTA_NAT_PROTO]) - return 0; - - err = nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO], ct, range); - if (err < 0) - return err; - - return 0; -} - -static int -nfnetlink_parse_nat_setup(struct nf_conn *ct, - enum nf_nat_manip_type manip, - const struct nlattr *attr) -{ - struct nf_nat_ipv4_range range; - - if (nfnetlink_parse_nat(attr, ct, &range) < 0) - return -EINVAL; - 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->ipv4.nat_htable_size = net->ct.htable_size; - net->ipv4.nat_bysource = nf_ct_alloc_hashtable(&net->ipv4.nat_htable_size, 0); - if (!net->ipv4.nat_bysource) - return -ENOMEM; - return 0; -} - -/* Clear NAT section of all conntracks, in case we're loaded again. */ -static int clean_nat(struct nf_conn *i, void *data) -{ - struct nf_conn_nat *nat = nfct_nat(i); - - if (!nat) - return 0; - memset(nat, 0, sizeof(*nat)); - i->status &= ~(IPS_NAT_MASK | IPS_NAT_DONE_MASK | IPS_SEQ_ADJUST); - return 0; -} - -static void __net_exit nf_nat_net_exit(struct net *net) -{ - nf_ct_iterate_cleanup(net, &clean_nat, NULL); - synchronize_rcu(); - nf_ct_free_hashtable(net->ipv4.nat_bysource, net->ipv4.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) -{ - size_t i; - int ret; - - need_ipv4_conntrack(); - - 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; - - /* Sew in builtin protocols. */ - spin_lock_bh(&nf_nat_lock); - for (i = 0; i < MAX_IP_NAT_PROTO; i++) - RCU_INIT_POINTER(nf_nat_protos[i], &nf_nat_unknown_protocol); - RCU_INIT_POINTER(nf_nat_protos[IPPROTO_TCP], &nf_nat_protocol_tcp); - RCU_INIT_POINTER(nf_nat_protos[IPPROTO_UDP], &nf_nat_protocol_udp); - RCU_INIT_POINTER(nf_nat_protos[IPPROTO_ICMP], &nf_nat_protocol_icmp); - spin_unlock_bh(&nf_nat_lock); - - /* Initialize fake conntrack so that NAT will skip it */ - nf_ct_untracked_status_or(IPS_NAT_DONE_MASK); - - l3proto = nf_ct_l3proto_find_get((u_int16_t)AF_INET); - - nf_ct_helper_expectfn_register(&follow_master_nat); - - 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); - return 0; - - cleanup_extend: - nf_ct_extend_unregister(&nat_extend); - return ret; -} - -static void __exit nf_nat_cleanup(void) -{ - unregister_pernet_subsys(&nf_nat_net_ops); - nf_ct_l3proto_put(l3proto); - 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); - synchronize_net(); -} - -MODULE_LICENSE("GPL"); -MODULE_ALIAS("nf-nat-ipv4"); - -module_init(nf_nat_init); -module_exit(nf_nat_cleanup); -- cgit v1.2.3