| /* |
| * (C) 1999-2001 Paul `Rusty' Russell |
| * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> |
| * (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. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/timer.h> |
| #include <linux/skbuff.h> |
| #include <linux/gfp.h> |
| #include <net/xfrm.h> |
| #include <linux/jhash.h> |
| #include <linux/rtnetlink.h> |
| |
| #include <net/netfilter/nf_conntrack.h> |
| #include <net/netfilter/nf_conntrack_core.h> |
| #include <net/netfilter/nf_nat.h> |
| #include <net/netfilter/nf_nat_l3proto.h> |
| #include <net/netfilter/nf_nat_l4proto.h> |
| #include <net/netfilter/nf_nat_core.h> |
| #include <net/netfilter/nf_nat_helper.h> |
| #include <net/netfilter/nf_conntrack_helper.h> |
| #include <net/netfilter/nf_conntrack_seqadj.h> |
| #include <net/netfilter/nf_conntrack_l3proto.h> |
| #include <net/netfilter/nf_conntrack_zones.h> |
| #include <linux/netfilter/nf_nat.h> |
| |
| static spinlock_t nf_nat_locks[CONNTRACK_LOCKS]; |
| |
| 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; |
| |
| static struct hlist_head *nf_nat_bysource __read_mostly; |
| static unsigned int nf_nat_htable_size __read_mostly; |
| static unsigned int nf_nat_hash_rnd __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 = nf_ct_l3num(ct); |
| l3proto = __nf_nat_l3proto_find(family); |
| if (l3proto == NULL) |
| return; |
| |
| 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); |
| } |
| |
| int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family) |
| { |
| struct flowi fl; |
| unsigned int hh_len; |
| struct dst_entry *dst; |
| int err; |
| |
| err = xfrm_decode_session(skb, &fl, family); |
| if (err < 0) |
| return err; |
| |
| dst = skb_dst(skb); |
| if (dst->xfrm) |
| dst = ((struct xfrm_dst *)dst)->route; |
| dst_hold(dst); |
| |
| dst = xfrm_lookup(net, dst, &fl, skb->sk, 0); |
| if (IS_ERR(dst)) |
| return PTR_ERR(dst); |
| |
| 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 -ENOMEM; |
| return 0; |
| } |
| EXPORT_SYMBOL(nf_xfrm_me_harder); |
| #endif /* CONFIG_XFRM */ |
| |
| /* We keep an extra hash for each conntrack, for fast searching. */ |
| static unsigned int |
| hash_by_src(const struct net *n, const struct nf_conntrack_tuple *tuple) |
| { |
| unsigned int hash; |
| |
| get_random_once(&nf_nat_hash_rnd, sizeof(nf_nat_hash_rnd)); |
| |
| /* Original src, to ensure we map it consistently if poss. */ |
| hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32), |
| tuple->dst.protonum ^ nf_nat_hash_rnd ^ net_hash_mix(n)); |
| |
| return reciprocal_scale(hash, nf_nat_htable_size); |
| } |
| |
| /* 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, |
| const struct nf_conntrack_zone *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, tuple); |
| const struct nf_conn *ct; |
| |
| hlist_for_each_entry_rcu(ct, &nf_nat_bysource[h], nat_bysource) { |
| if (same_src(ct, tuple) && |
| net_eq(net, nf_ct_net(ct)) && |
| nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL)) { |
| /* 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(const struct nf_conntrack_zone *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->id); |
| |
| 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 + reciprocal_scale(j, dist)); |
| 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_conntrack_zone *zone; |
| const struct nf_nat_l3proto *l3proto; |
| const struct nf_nat_l4proto *l4proto; |
| struct net *net = nf_ct_net(ct); |
| |
| 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_ALL)) { |
| /* 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_ALL)) { |
| 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(); |
| } |
| |
| struct nf_conn_nat *nf_ct_nat_ext_add(struct nf_conn *ct) |
| { |
| struct nf_conn_nat *nat = nfct_nat(ct); |
| if (nat) |
| return nat; |
| |
| if (!nf_ct_is_confirmed(ct)) |
| nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC); |
| |
| return nat; |
| } |
| EXPORT_SYMBOL_GPL(nf_ct_nat_ext_add); |
| |
| 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; |
| |
| /* Can't setup nat info for confirmed ct. */ |
| if (nf_ct_is_confirmed(ct)) |
| return NF_ACCEPT; |
| |
| WARN_ON(maniptype != NF_NAT_MANIP_SRC && |
| maniptype != NF_NAT_MANIP_DST); |
| |
| if (WARN_ON(nf_nat_initialized(ct, maniptype))) |
| return NF_DROP; |
| |
| /* 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 (nfct_help(ct) && !nfct_seqadj(ct)) |
| if (!nfct_seqadj_ext_add(ct)) |
| return NF_DROP; |
| } |
| |
| if (maniptype == NF_NAT_MANIP_SRC) { |
| unsigned int srchash; |
| spinlock_t *lock; |
| |
| srchash = hash_by_src(net, |
| &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); |
| lock = &nf_nat_locks[srchash % CONNTRACK_LOCKS]; |
| spin_lock_bh(lock); |
| hlist_add_head_rcu(&ct->nat_bysource, |
| &nf_nat_bysource[srchash]); |
| spin_unlock_bh(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); |
| |
| static unsigned int |
| __nf_nat_alloc_null_binding(struct nf_conn *ct, enum nf_nat_manip_type manip) |
| { |
| /* Force range to this IP; let proto decide mapping for |
| * per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED). |
| * Use reply in case it's already been mangled (eg local packet). |
| */ |
| union nf_inet_addr ip = |
| (manip == NF_NAT_MANIP_SRC ? |
| ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3 : |
| ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3); |
| struct nf_nat_range range = { |
| .flags = NF_NAT_RANGE_MAP_IPS, |
| .min_addr = ip, |
| .max_addr = ip, |
| }; |
| return nf_nat_setup_info(ct, &range, manip); |
| } |
| |
| unsigned int |
| nf_nat_alloc_null_binding(struct nf_conn *ct, unsigned int hooknum) |
| { |
| return __nf_nat_alloc_null_binding(ct, HOOK2MANIP(hooknum)); |
| } |
| EXPORT_SYMBOL_GPL(nf_nat_alloc_null_binding); |
| |
| /* 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; |
| }; |
| |
| /* kill conntracks with affected NAT section */ |
| static int nf_nat_proto_remove(struct nf_conn *i, void *data) |
| { |
| const struct nf_nat_proto_clean *clean = data; |
| |
| if ((clean->l3proto && nf_ct_l3num(i) != clean->l3proto) || |
| (clean->l4proto && nf_ct_protonum(i) != clean->l4proto)) |
| return 0; |
| |
| return i->status & IPS_NAT_MASK ? 1 : 0; |
| } |
| |
| static void __nf_nat_cleanup_conntrack(struct nf_conn *ct) |
| { |
| unsigned int h; |
| |
| h = hash_by_src(nf_ct_net(ct), &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); |
| spin_lock_bh(&nf_nat_locks[h % CONNTRACK_LOCKS]); |
| hlist_del_rcu(&ct->nat_bysource); |
| spin_unlock_bh(&nf_nat_locks[h % CONNTRACK_LOCKS]); |
| } |
| |
| static int nf_nat_proto_clean(struct nf_conn *ct, void *data) |
| { |
| if (nf_nat_proto_remove(ct, data)) |
| return 1; |
| |
| if ((ct->status & IPS_SRC_NAT_DONE) == 0) |
| return 0; |
| |
| /* This netns is being destroyed, and conntrack has nat null binding. |
| * Remove it from bysource hash, as the table will be freed soon. |
| * |
| * Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack() |
| * will delete entry from already-freed table. |
| */ |
| clear_bit(IPS_SRC_NAT_DONE_BIT, &ct->status); |
| __nf_nat_cleanup_conntrack(ct); |
| |
| /* don't delete conntrack. Although that would make things a lot |
| * simpler, we'd end up flushing all conntracks on nat rmmod. |
| */ |
| return 0; |
| } |
| |
| static void nf_nat_l4proto_clean(u8 l3proto, u8 l4proto) |
| { |
| struct nf_nat_proto_clean clean = { |
| .l3proto = l3proto, |
| .l4proto = l4proto, |
| }; |
| |
| nf_ct_iterate_destroy(nf_nat_proto_remove, &clean); |
| } |
| |
| static void nf_nat_l3proto_clean(u8 l3proto) |
| { |
| struct nf_nat_proto_clean clean = { |
| .l3proto = l3proto, |
| }; |
| |
| nf_ct_iterate_destroy(nf_nat_proto_remove, &clean); |
| } |
| |
| /* 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); |
| #ifdef CONFIG_NF_NAT_PROTO_DCCP |
| RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_DCCP], |
| &nf_nat_l4proto_dccp); |
| #endif |
| #ifdef CONFIG_NF_NAT_PROTO_SCTP |
| RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_SCTP], |
| &nf_nat_l4proto_sctp); |
| #endif |
| #ifdef CONFIG_NF_NAT_PROTO_UDPLITE |
| RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_UDPLITE], |
| &nf_nat_l4proto_udplite); |
| #endif |
| 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) |
| { |
| if (ct->status & IPS_SRC_NAT_DONE) |
| __nf_nat_cleanup_conntrack(ct); |
| } |
| |
| 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, |
| .id = NF_CT_EXT_NAT, |
| }; |
| |
| #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
| |
| #include <linux/netfilter/nfnetlink.h> |
| #include <linux/netfilter/nfnetlink_conntrack.h> |
| |
| 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, NULL); |
| 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, NULL); |
| if (err < 0) |
| return err; |
| |
| err = l3proto->nlattr_to_range(tb, range); |
| if (err < 0) |
| return err; |
| |
| if (!tb[CTA_NAT_PROTO]) |
| return 0; |
| |
| return nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO], ct, range); |
| } |
| |
| /* This function is called under rcu_read_lock() */ |
| 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; |
| const struct nf_nat_l3proto *l3proto; |
| int err; |
| |
| /* Should not happen, restricted to creating new conntracks |
| * via ctnetlink. |
| */ |
| if (WARN_ON_ONCE(nf_nat_initialized(ct, manip))) |
| return -EEXIST; |
| |
| /* Make sure that L3 NAT is there by when we call nf_nat_setup_info to |
| * attach the null binding, otherwise this may oops. |
| */ |
| l3proto = __nf_nat_l3proto_find(nf_ct_l3num(ct)); |
| if (l3proto == NULL) |
| return -EAGAIN; |
| |
| /* No NAT information has been passed, allocate the null-binding */ |
| if (attr == NULL) |
| return __nf_nat_alloc_null_binding(ct, manip) == NF_DROP ? -ENOMEM : 0; |
| |
| err = nfnetlink_parse_nat(attr, ct, &range, l3proto); |
| if (err < 0) |
| return err; |
| |
| return nf_nat_setup_info(ct, &range, manip) == NF_DROP ? -ENOMEM : 0; |
| } |
| #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 struct nf_ct_helper_expectfn follow_master_nat = { |
| .name = "nat-follow-master", |
| .expectfn = nf_nat_follow_master, |
| }; |
| |
| static int __init nf_nat_init(void) |
| { |
| int ret, i; |
| |
| /* Leave them the same for the moment. */ |
| nf_nat_htable_size = nf_conntrack_htable_size; |
| if (nf_nat_htable_size < CONNTRACK_LOCKS) |
| nf_nat_htable_size = CONNTRACK_LOCKS; |
| |
| nf_nat_bysource = nf_ct_alloc_hashtable(&nf_nat_htable_size, 0); |
| if (!nf_nat_bysource) |
| return -ENOMEM; |
| |
| ret = nf_ct_extend_register(&nat_extend); |
| if (ret < 0) { |
| nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size); |
| printk(KERN_ERR "nf_nat_core: Unable to register extension\n"); |
| return ret; |
| } |
| |
| for (i = 0; i < CONNTRACK_LOCKS; i++) |
| spin_lock_init(&nf_nat_locks[i]); |
| |
| nf_ct_helper_expectfn_register(&follow_master_nat); |
| |
| BUG_ON(nfnetlink_parse_nat_setup_hook != NULL); |
| RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook, |
| nfnetlink_parse_nat_setup); |
| #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; |
| } |
| |
| static void __exit nf_nat_cleanup(void) |
| { |
| struct nf_nat_proto_clean clean = {}; |
| unsigned int i; |
| |
| nf_ct_iterate_destroy(nf_nat_proto_clean, &clean); |
| |
| nf_ct_extend_unregister(&nat_extend); |
| nf_ct_helper_expectfn_unregister(&follow_master_nat); |
| RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook, NULL); |
| #ifdef CONFIG_XFRM |
| RCU_INIT_POINTER(nf_nat_decode_session_hook, NULL); |
| #endif |
| synchronize_rcu(); |
| |
| for (i = 0; i < NFPROTO_NUMPROTO; i++) |
| kfree(nf_nat_l4protos[i]); |
| synchronize_net(); |
| nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size); |
| } |
| |
| MODULE_LICENSE("GPL"); |
| |
| module_init(nf_nat_init); |
| module_exit(nf_nat_cleanup); |