![Thierry Du Tre](/assets/img/avatar_default.png)
This is a patch proposal to support shifted ranges in portmaps. (i.e. tcp/udp incoming port 5000-5100 on WAN redirected to LAN 192.168.1.5:2000-2100) Currently DNAT only works for single port or identical port ranges. (i.e. ports 5000-5100 on WAN interface redirected to a LAN host while original destination port is not altered) When different port ranges are configured, either 'random' mode should be used, or else all incoming connections are mapped onto the first port in the redirect range. (in described example WAN:5000-5100 will all be mapped to 192.168.1.5:2000) This patch introduces a new mode indicated by flag NF_NAT_RANGE_PROTO_OFFSET which uses a base port value to calculate an offset with the destination port present in the incoming stream. That offset is then applied as index within the redirect port range (index modulo rangewidth to handle range overflow). In described example the base port would be 5000. An incoming stream with destination port 5004 would result in an offset value 4 which means that the NAT'ed stream will be using destination port 2004. Other possibilities include deterministic mapping of larger or multiple ranges to a smaller range : WAN:5000-5999 -> LAN:5000-5099 (maps WAN port 5*xx to port 51xx) This patch does not change any current behavior. It just adds new NAT proto range functionality which must be selected via the specific flag when intended to use. A patch for iptables (libipt_DNAT.c + libip6t_DNAT.c) will also be proposed which makes this functionality immediately available. Signed-off-by: Thierry Du Tre <thierry@dtsystems.be> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
864 lines
24 KiB
C
864 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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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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 spinlock_t nf_nat_locks[CONNTRACK_LOCKS];
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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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static struct hlist_head *nf_nat_bysource __read_mostly;
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static unsigned int nf_nat_htable_size __read_mostly;
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static unsigned int nf_nat_hash_rnd __read_mostly;
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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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/* We keep an extra hash for each conntrack, for fast searching. */
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static unsigned int
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hash_by_src(const struct net *n, const struct nf_conntrack_tuple *tuple)
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{
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unsigned int hash;
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get_random_once(&nf_nat_hash_rnd, sizeof(nf_nat_hash_rnd));
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/* Original src, to ensure we map it consistently if poss. */
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hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32),
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tuple->dst.protonum ^ nf_nat_hash_rnd ^ net_hash_mix(n));
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return reciprocal_scale(hash, nf_nat_htable_size);
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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_range2 *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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/* 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_range2 *range)
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{
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unsigned int h = hash_by_src(net, tuple);
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const struct nf_conn *ct;
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hlist_for_each_entry_rcu(ct, &nf_nat_bysource[h], nat_bysource) {
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if (same_src(ct, tuple) &&
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net_eq(net, nf_ct_net(ct)) &&
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nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL)) {
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/* Copy source part from reply tuple. */
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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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if (in_range(l3proto, l4proto, result, range))
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return 1;
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}
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}
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return 0;
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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_range2 *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_range2 *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 (!(range->flags & NF_NAT_RANGE_PROTO_OFFSET) &&
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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 chance: 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_range2 *range,
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enum nf_nat_manip_type maniptype)
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{
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struct net *net = nf_ct_net(ct);
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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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WARN_ON(maniptype != NF_NAT_MANIP_SRC &&
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maniptype != NF_NAT_MANIP_DST);
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if (WARN_ON(nf_nat_initialized(ct, maniptype)))
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return NF_DROP;
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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)) {
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struct nf_conntrack_tuple reply;
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/* Alter conntrack table so will recognize replies. */
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nf_ct_invert_tuplepr(&reply, &new_tuple);
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nf_conntrack_alter_reply(ct, &reply);
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/* Non-atomic: we own this at the moment. */
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if (maniptype == NF_NAT_MANIP_SRC)
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ct->status |= IPS_SRC_NAT;
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else
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ct->status |= IPS_DST_NAT;
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if (nfct_help(ct) && !nfct_seqadj(ct))
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if (!nfct_seqadj_ext_add(ct))
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return NF_DROP;
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}
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if (maniptype == NF_NAT_MANIP_SRC) {
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unsigned int srchash;
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spinlock_t *lock;
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srchash = hash_by_src(net,
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&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
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lock = &nf_nat_locks[srchash % CONNTRACK_LOCKS];
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spin_lock_bh(lock);
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hlist_add_head_rcu(&ct->nat_bysource,
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&nf_nat_bysource[srchash]);
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spin_unlock_bh(lock);
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}
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|
/* 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_range2 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;
|
|
|
|
/* This module is being removed 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.
|
|
*/
|
|
if (test_and_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_range2 *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_range2 *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_range2 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);
|
|
pr_err("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);
|