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![David S. Miller](/assets/img/avatar_default.png)
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for your net-next tree. This batch contains connection tracking updates for the cleanup iteration path, patches from Florian Westphal: X) Skip unconfirmed conntracks in nf_ct_iterate_cleanup_net(), just set dying bit to let the CPU release them. X) Add nf_ct_iterate_destroy() to be used on module removal, to kill conntrack from all namespace. X) Restart iteration on hashtable resizing, since both may occur at the same time. X) Use the new nf_ct_iterate_destroy() to remove conntrack with NAT mapping on module removal. X) Use nf_ct_iterate_destroy() to remove conntrack entries helper module removal, from Liping Zhang. X) Use nf_ct_iterate_cleanup_net() to remove the timeout extension if user requests this, also from Liping. X) Add net_ns_barrier() and use it from FTP helper, so make sure no concurrent namespace removal happens at the same time while the helper module is being removed. X) Use NFPROTO_MAX in layer 3 conntrack protocol array, to reduce module size. Same thing in nf_tables. Updates for the nf_tables infrastructure: X) Prepare usage of the extended ACK reporting infrastructure for nf_tables. X) Remove unnecessary forward declaration in nf_tables hash set. X) Skip set size estimation if number of element is not specified. X) Changes to accomodate a (faster) unresizable hash set implementation, for anonymous sets and dynamic size fixed sets with no timeouts. X) Faster lookup function for unresizable hash table for 2 and 4 bytes key. And, finally, a bunch of asorted small updates and cleanups: X) Do not hold reference to netdev from ipt_CLUSTER, instead subscribe to device events and look up for index from the packet path, this is fixing an issue that is present since the very beginning, patch from Xin Long. X) Use nf_register_net_hook() in ipt_CLUSTER, from Florian Westphal. X) Use ebt_invalid_target() whenever possible in the ebtables tree, from Gao Feng. X) Calm down compilation warning in nf_dup infrastructure, patch from stephen hemminger. X) Statify functions in nftables rt expression, also from stephen. X) Update Makefile to use canonical method to specify nf_tables-objs. From Jike Song. X) Use nf_conntrack_helpers_register() in amanda and H323. X) Space cleanup for ctnetlink, from linzhang. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
872 lines
24 KiB
C
872 lines
24 KiB
C
/*
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* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
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* (C) 2011 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/timer.h>
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#include <linux/skbuff.h>
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#include <linux/gfp.h>
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#include <net/xfrm.h>
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#include <linux/jhash.h>
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#include <linux/rtnetlink.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_core.h>
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#include <net/netfilter/nf_nat.h>
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#include <net/netfilter/nf_nat_l3proto.h>
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#include <net/netfilter/nf_nat_l4proto.h>
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#include <net/netfilter/nf_nat_core.h>
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#include <net/netfilter/nf_nat_helper.h>
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#include <net/netfilter/nf_conntrack_helper.h>
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#include <net/netfilter/nf_conntrack_seqadj.h>
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#include <net/netfilter/nf_conntrack_l3proto.h>
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#include <net/netfilter/nf_conntrack_zones.h>
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#include <linux/netfilter/nf_nat.h>
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static DEFINE_MUTEX(nf_nat_proto_mutex);
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static const struct nf_nat_l3proto __rcu *nf_nat_l3protos[NFPROTO_NUMPROTO]
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__read_mostly;
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static const struct nf_nat_l4proto __rcu **nf_nat_l4protos[NFPROTO_NUMPROTO]
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__read_mostly;
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struct nf_nat_conn_key {
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const struct net *net;
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const struct nf_conntrack_tuple *tuple;
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const struct nf_conntrack_zone *zone;
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};
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static struct rhltable nf_nat_bysource_table;
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inline const struct nf_nat_l3proto *
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__nf_nat_l3proto_find(u8 family)
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{
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return rcu_dereference(nf_nat_l3protos[family]);
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}
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inline const struct nf_nat_l4proto *
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__nf_nat_l4proto_find(u8 family, u8 protonum)
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{
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return rcu_dereference(nf_nat_l4protos[family][protonum]);
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}
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EXPORT_SYMBOL_GPL(__nf_nat_l4proto_find);
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#ifdef CONFIG_XFRM
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static void __nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl)
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{
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const struct nf_nat_l3proto *l3proto;
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const struct nf_conn *ct;
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enum ip_conntrack_info ctinfo;
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enum ip_conntrack_dir dir;
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unsigned long statusbit;
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u8 family;
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ct = nf_ct_get(skb, &ctinfo);
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if (ct == NULL)
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return;
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family = nf_ct_l3num(ct);
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l3proto = __nf_nat_l3proto_find(family);
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if (l3proto == NULL)
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return;
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dir = CTINFO2DIR(ctinfo);
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if (dir == IP_CT_DIR_ORIGINAL)
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statusbit = IPS_DST_NAT;
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else
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statusbit = IPS_SRC_NAT;
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l3proto->decode_session(skb, ct, dir, statusbit, fl);
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}
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int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
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{
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struct flowi fl;
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unsigned int hh_len;
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struct dst_entry *dst;
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int err;
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err = xfrm_decode_session(skb, &fl, family);
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if (err < 0)
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return err;
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dst = skb_dst(skb);
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if (dst->xfrm)
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dst = ((struct xfrm_dst *)dst)->route;
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dst_hold(dst);
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dst = xfrm_lookup(net, dst, &fl, skb->sk, 0);
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if (IS_ERR(dst))
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return PTR_ERR(dst);
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skb_dst_drop(skb);
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skb_dst_set(skb, dst);
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/* Change in oif may mean change in hh_len. */
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hh_len = skb_dst(skb)->dev->hard_header_len;
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if (skb_headroom(skb) < hh_len &&
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pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
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return -ENOMEM;
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return 0;
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}
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EXPORT_SYMBOL(nf_xfrm_me_harder);
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#endif /* CONFIG_XFRM */
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static u32 nf_nat_bysource_hash(const void *data, u32 len, u32 seed)
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{
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const struct nf_conntrack_tuple *t;
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const struct nf_conn *ct = data;
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t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
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/* Original src, to ensure we map it consistently if poss. */
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seed ^= net_hash_mix(nf_ct_net(ct));
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return jhash2((const u32 *)&t->src, sizeof(t->src) / sizeof(u32),
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t->dst.protonum ^ seed);
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}
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/* Is this tuple already taken? (not by us) */
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int
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nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
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const struct nf_conn *ignored_conntrack)
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{
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/* Conntrack tracking doesn't keep track of outgoing tuples; only
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* incoming ones. NAT means they don't have a fixed mapping,
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* so we invert the tuple and look for the incoming reply.
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*
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* We could keep a separate hash if this proves too slow.
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*/
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struct nf_conntrack_tuple reply;
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nf_ct_invert_tuplepr(&reply, tuple);
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return nf_conntrack_tuple_taken(&reply, ignored_conntrack);
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}
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EXPORT_SYMBOL(nf_nat_used_tuple);
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/* If we source map this tuple so reply looks like reply_tuple, will
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* that meet the constraints of range.
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*/
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static int in_range(const struct nf_nat_l3proto *l3proto,
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const struct nf_nat_l4proto *l4proto,
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const struct nf_conntrack_tuple *tuple,
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const struct nf_nat_range *range)
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{
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/* If we are supposed to map IPs, then we must be in the
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* range specified, otherwise let this drag us onto a new src IP.
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*/
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if (range->flags & NF_NAT_RANGE_MAP_IPS &&
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!l3proto->in_range(tuple, range))
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return 0;
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if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) ||
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l4proto->in_range(tuple, NF_NAT_MANIP_SRC,
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&range->min_proto, &range->max_proto))
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return 1;
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return 0;
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}
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static inline int
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same_src(const struct nf_conn *ct,
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const struct nf_conntrack_tuple *tuple)
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{
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const struct nf_conntrack_tuple *t;
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t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
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return (t->dst.protonum == tuple->dst.protonum &&
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nf_inet_addr_cmp(&t->src.u3, &tuple->src.u3) &&
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t->src.u.all == tuple->src.u.all);
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}
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static int nf_nat_bysource_cmp(struct rhashtable_compare_arg *arg,
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const void *obj)
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{
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const struct nf_nat_conn_key *key = arg->key;
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const struct nf_conn *ct = obj;
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if (!same_src(ct, key->tuple) ||
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!net_eq(nf_ct_net(ct), key->net) ||
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!nf_ct_zone_equal(ct, key->zone, IP_CT_DIR_ORIGINAL))
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return 1;
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return 0;
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}
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static struct rhashtable_params nf_nat_bysource_params = {
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.head_offset = offsetof(struct nf_conn, nat_bysource),
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.obj_hashfn = nf_nat_bysource_hash,
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.obj_cmpfn = nf_nat_bysource_cmp,
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.nelem_hint = 256,
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.min_size = 1024,
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};
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/* Only called for SRC manip */
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static int
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find_appropriate_src(struct net *net,
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const struct nf_conntrack_zone *zone,
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const struct nf_nat_l3proto *l3proto,
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const struct nf_nat_l4proto *l4proto,
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const struct nf_conntrack_tuple *tuple,
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struct nf_conntrack_tuple *result,
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const struct nf_nat_range *range)
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{
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const struct nf_conn *ct;
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struct nf_nat_conn_key key = {
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.net = net,
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.tuple = tuple,
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.zone = zone
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};
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struct rhlist_head *hl;
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hl = rhltable_lookup(&nf_nat_bysource_table, &key,
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nf_nat_bysource_params);
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if (!hl)
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return 0;
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ct = container_of(hl, typeof(*ct), nat_bysource);
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nf_ct_invert_tuplepr(result,
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&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
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result->dst = tuple->dst;
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return in_range(l3proto, l4proto, result, range);
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}
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/* For [FUTURE] fragmentation handling, we want the least-used
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* src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus
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* if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
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* 1-65535, we don't do pro-rata allocation based on ports; we choose
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* the ip with the lowest src-ip/dst-ip/proto usage.
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*/
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static void
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find_best_ips_proto(const struct nf_conntrack_zone *zone,
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struct nf_conntrack_tuple *tuple,
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const struct nf_nat_range *range,
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const struct nf_conn *ct,
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enum nf_nat_manip_type maniptype)
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{
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union nf_inet_addr *var_ipp;
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unsigned int i, max;
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/* Host order */
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u32 minip, maxip, j, dist;
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bool full_range;
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/* No IP mapping? Do nothing. */
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if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
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return;
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if (maniptype == NF_NAT_MANIP_SRC)
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var_ipp = &tuple->src.u3;
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else
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var_ipp = &tuple->dst.u3;
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/* Fast path: only one choice. */
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if (nf_inet_addr_cmp(&range->min_addr, &range->max_addr)) {
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*var_ipp = range->min_addr;
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return;
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}
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if (nf_ct_l3num(ct) == NFPROTO_IPV4)
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max = sizeof(var_ipp->ip) / sizeof(u32) - 1;
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else
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max = sizeof(var_ipp->ip6) / sizeof(u32) - 1;
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/* Hashing source and destination IPs gives a fairly even
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* spread in practice (if there are a small number of IPs
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* involved, there usually aren't that many connections
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* anyway). The consistency means that servers see the same
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* client coming from the same IP (some Internet Banking sites
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* like this), even across reboots.
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*/
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j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3) / sizeof(u32),
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range->flags & NF_NAT_RANGE_PERSISTENT ?
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0 : (__force u32)tuple->dst.u3.all[max] ^ zone->id);
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full_range = false;
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for (i = 0; i <= max; i++) {
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/* If first bytes of the address are at the maximum, use the
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* distance. Otherwise use the full range.
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*/
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if (!full_range) {
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minip = ntohl((__force __be32)range->min_addr.all[i]);
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maxip = ntohl((__force __be32)range->max_addr.all[i]);
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dist = maxip - minip + 1;
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} else {
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minip = 0;
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dist = ~0;
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}
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var_ipp->all[i] = (__force __u32)
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htonl(minip + reciprocal_scale(j, dist));
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if (var_ipp->all[i] != range->max_addr.all[i])
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full_range = true;
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if (!(range->flags & NF_NAT_RANGE_PERSISTENT))
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j ^= (__force u32)tuple->dst.u3.all[i];
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}
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}
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/* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
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* we change the source to map into the range. For NF_INET_PRE_ROUTING
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* and NF_INET_LOCAL_OUT, we change the destination to map into the
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* range. It might not be possible to get a unique tuple, but we try.
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* At worst (or if we race), we will end up with a final duplicate in
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* __ip_conntrack_confirm and drop the packet. */
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static void
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get_unique_tuple(struct nf_conntrack_tuple *tuple,
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const struct nf_conntrack_tuple *orig_tuple,
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const struct nf_nat_range *range,
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struct nf_conn *ct,
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enum nf_nat_manip_type maniptype)
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{
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const struct nf_conntrack_zone *zone;
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const struct nf_nat_l3proto *l3proto;
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const struct nf_nat_l4proto *l4proto;
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struct net *net = nf_ct_net(ct);
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zone = nf_ct_zone(ct);
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rcu_read_lock();
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l3proto = __nf_nat_l3proto_find(orig_tuple->src.l3num);
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l4proto = __nf_nat_l4proto_find(orig_tuple->src.l3num,
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orig_tuple->dst.protonum);
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/* 1) If this srcip/proto/src-proto-part is currently mapped,
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* and that same mapping gives a unique tuple within the given
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* range, use that.
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*
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* This is only required for source (ie. NAT/masq) mappings.
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* So far, we don't do local source mappings, so multiple
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* manips not an issue.
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*/
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if (maniptype == NF_NAT_MANIP_SRC &&
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!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
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/* try the original tuple first */
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if (in_range(l3proto, l4proto, orig_tuple, range)) {
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if (!nf_nat_used_tuple(orig_tuple, ct)) {
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*tuple = *orig_tuple;
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goto out;
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}
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} else if (find_appropriate_src(net, zone, l3proto, l4proto,
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orig_tuple, tuple, range)) {
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pr_debug("get_unique_tuple: Found current src map\n");
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if (!nf_nat_used_tuple(tuple, ct))
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goto out;
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}
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}
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/* 2) Select the least-used IP/proto combination in the given range */
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*tuple = *orig_tuple;
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find_best_ips_proto(zone, tuple, range, ct, maniptype);
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/* 3) The per-protocol part of the manip is made to map into
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* the range to make a unique tuple.
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*/
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/* Only bother mapping if it's not already in range and unique */
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if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
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if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
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if (l4proto->in_range(tuple, maniptype,
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&range->min_proto,
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&range->max_proto) &&
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(range->min_proto.all == range->max_proto.all ||
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!nf_nat_used_tuple(tuple, ct)))
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goto out;
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} else if (!nf_nat_used_tuple(tuple, ct)) {
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goto out;
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}
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}
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/* Last change: get protocol to try to obtain unique tuple. */
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l4proto->unique_tuple(l3proto, tuple, range, maniptype, ct);
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out:
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rcu_read_unlock();
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}
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struct nf_conn_nat *nf_ct_nat_ext_add(struct nf_conn *ct)
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{
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struct nf_conn_nat *nat = nfct_nat(ct);
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if (nat)
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return nat;
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if (!nf_ct_is_confirmed(ct))
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nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
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return nat;
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}
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EXPORT_SYMBOL_GPL(nf_ct_nat_ext_add);
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unsigned int
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nf_nat_setup_info(struct nf_conn *ct,
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const struct nf_nat_range *range,
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enum nf_nat_manip_type maniptype)
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{
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struct nf_conntrack_tuple curr_tuple, new_tuple;
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/* Can't setup nat info for confirmed ct. */
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if (nf_ct_is_confirmed(ct))
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return NF_ACCEPT;
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NF_CT_ASSERT(maniptype == NF_NAT_MANIP_SRC ||
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maniptype == NF_NAT_MANIP_DST);
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BUG_ON(nf_nat_initialized(ct, maniptype));
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/* What we've got will look like inverse of reply. Normally
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* this is what is in the conntrack, except for prior
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* manipulations (future optimization: if num_manips == 0,
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* orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
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*/
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nf_ct_invert_tuplepr(&curr_tuple,
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&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
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get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);
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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))
|
|
if (!nfct_seqadj_ext_add(ct))
|
|
return NF_DROP;
|
|
}
|
|
|
|
if (maniptype == NF_NAT_MANIP_SRC) {
|
|
struct nf_nat_conn_key key = {
|
|
.net = nf_ct_net(ct),
|
|
.tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
|
|
.zone = nf_ct_zone(ct),
|
|
};
|
|
int err;
|
|
|
|
err = rhltable_insert_key(&nf_nat_bysource_table,
|
|
&key,
|
|
&ct->nat_bysource,
|
|
nf_nat_bysource_params);
|
|
if (err)
|
|
return NF_DROP;
|
|
}
|
|
|
|
/* 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 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);
|
|
rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
|
|
nf_nat_bysource_params);
|
|
|
|
/* 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)
|
|
rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
|
|
nf_nat_bysource_params);
|
|
}
|
|
|
|
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;
|
|
|
|
ret = rhltable_init(&nf_nat_bysource_table, &nf_nat_bysource_params);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = nf_ct_extend_register(&nat_extend);
|
|
if (ret < 0) {
|
|
rhltable_destroy(&nf_nat_bysource_table);
|
|
printk(KERN_ERR "nf_nat_core: Unable to register extension\n");
|
|
return ret;
|
|
}
|
|
|
|
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]);
|
|
|
|
rhltable_destroy(&nf_nat_bysource_table);
|
|
}
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(nf_nat_init);
|
|
module_exit(nf_nat_cleanup);
|