cregit-Linux how code gets into the kernel

Release 4.11 net/netfilter/nf_nat_core.c

Directory: net/netfilter
/*
 * (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
 * (C) 2011 Patrick McHardy <kaber@trash.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/skbuff.h>
#include <linux/gfp.h>
#include <net/xfrm.h>
#include <linux/jhash.h>
#include <linux/rtnetlink.h>

#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_l3proto.h>
#include <net/netfilter/nf_nat_l4proto.h>
#include <net/netfilter/nf_nat_core.h>
#include <net/netfilter/nf_nat_helper.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_seqadj.h>
#include <net/netfilter/nf_conntrack_l3proto.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <linux/netfilter/nf_nat.h>

static DEFINE_MUTEX(nf_nat_proto_mutex);
static const struct nf_nat_l3proto __rcu *nf_nat_l3protos[NFPROTO_NUMPROTO]
						
__read_mostly;
static const struct nf_nat_l4proto __rcu **nf_nat_l4protos[NFPROTO_NUMPROTO]
						
__read_mostly;


struct nf_nat_conn_key {
	
const struct net *net;
	
const struct nf_conntrack_tuple *tuple;
	
const struct nf_conntrack_zone *zone;
};


static struct rhltable nf_nat_bysource_table;



inline const struct nf_nat_l3proto *

__nf_nat_l3proto_find(u8 family)
{
	return rcu_dereference(nf_nat_l3protos[family]);
}


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Jozsef Kadlecsik1152.38%125.00%


Patrick McHardy1047.62%375.00%


Total21100.00%4100.00%





inline const struct nf_nat_l4proto *

__nf_nat_l4proto_find(u8 family, u8 protonum)
{
	return rcu_dereference(nf_nat_l4protos[family][protonum]);
}

Contributors
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Patrick McHardy1659.26%266.67%


Jozsef Kadlecsik1140.74%133.33%


Total27100.00%3100.00%




EXPORT_SYMBOL_GPL(__nf_nat_l4proto_find);

#ifdef CONFIG_XFRM



static void __nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl)
{
	const struct nf_nat_l3proto *l3proto;
	const struct nf_conn *ct;
	enum ip_conntrack_info ctinfo;
	enum ip_conntrack_dir dir;
	unsigned  long statusbit;
	u8 family;

	ct = nf_ct_get(skb, &ctinfo);
	if (ct == NULL)
		return;

	family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
	rcu_read_lock();
	l3proto = __nf_nat_l3proto_find(family);
	if (l3proto == NULL)
		goto out;

	dir = CTINFO2DIR(ctinfo);
	if (dir == IP_CT_DIR_ORIGINAL)
		statusbit = IPS_DST_NAT;
	else
		statusbit = IPS_SRC_NAT;

	l3proto->decode_session(skb, ct, dir, statusbit, fl);
out:
	rcu_read_unlock();
}


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Patrick McHardy11383.09%375.00%


Jozsef Kadlecsik2316.91%125.00%


Total136100.00%4100.00%






int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
{
	struct flowi fl;
	unsigned int hh_len;
	struct dst_entry *dst;
	int err;

	err = xfrm_decode_session(skb, &fl, family);
	if (err < 0)
		return err;

	dst = skb_dst(skb);
	if (dst->xfrm)
		dst = ((struct xfrm_dst *)dst)->route;
	dst_hold(dst);

	dst = xfrm_lookup(net, dst, &fl, skb->sk, 0);
	if (IS_ERR(dst))
		return PTR_ERR(dst);

	skb_dst_drop(skb);
	skb_dst_set(skb, dst);

	/* Change in oif may mean change in hh_len. */
	hh_len = skb_dst(skb)->dev->hard_header_len;
	if (skb_headroom(skb) < hh_len &&
	    pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
		return -ENOMEM;
	return 0;
}

Contributors
PersonTokensPropCommitsCommitProp
Patrick McHardy14281.61%350.00%


Jozsef Kadlecsik2011.49%116.67%


Dan Carpenter63.45%116.67%


Eric W. Biedermann63.45%116.67%


Total174100.00%6100.00%




EXPORT_SYMBOL(nf_xfrm_me_harder);
#endif /* CONFIG_XFRM */




static u32 nf_nat_bysource_hash(const void *data, u32 len, u32 seed)
{
	const struct nf_conntrack_tuple *t;
	const struct nf_conn *ct = data;

	t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
	/* Original src, to ensure we map it consistently if poss. */

	seed ^= net_hash_mix(nf_ct_net(ct));
	return jhash2((const u32 *)&t->src, sizeof(t->src) / sizeof(u32),
		      t->dst.protonum ^ seed);
}


Contributors
PersonTokensPropCommitsCommitProp
Florian Westphal4955.68%233.33%


Patrick McHardy2730.68%116.67%


Jozsef Kadlecsik910.23%116.67%


Daniel Borkmann33.41%233.33%


Total88100.00%6100.00%



/* Is this tuple already taken? (not by us) */


int

nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
		  const struct nf_conn *ignored_conntrack)
{
	/* Conntrack tracking doesn't keep track of outgoing tuples; only
         * incoming ones.  NAT means they don't have a fixed mapping,
         * so we invert the tuple and look for the incoming reply.
         *
         * We could keep a separate hash if this proves too slow.
         */
	struct nf_conntrack_tuple reply;

	nf_ct_invert_tuplepr(&reply, tuple);
	return nf_conntrack_tuple_taken(&reply, ignored_conntrack);
}

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Total39100.00%1100.00%




EXPORT_SYMBOL(nf_nat_used_tuple);

/* If we source map this tuple so reply looks like reply_tuple, will
 * that meet the constraints of range.
 */



static int in_range(const struct nf_nat_l3proto *l3proto,
		    const struct nf_nat_l4proto *l4proto,
		    const struct nf_conntrack_tuple *tuple,
		    const struct nf_nat_range *range)
{
	/* If we are supposed to map IPs, then we must be in the
         * range specified, otherwise let this drag us onto a new src IP.
         */
	if (range->flags & NF_NAT_RANGE_MAP_IPS &&
	    !l3proto->in_range(tuple, range))
		return 0;

	if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) ||
	    l4proto->in_range(tuple, NF_NAT_MANIP_SRC,
			      &range->min_proto, &range->max_proto))
		return 1;

	return 0;
}


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Patrick McHardy88100.00%1100.00%


Total88100.00%1100.00%





static inline int

same_src(const struct nf_conn *ct,
	 const struct nf_conntrack_tuple *tuple)
{
	const struct nf_conntrack_tuple *t;

	t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
	return (t->dst.protonum == tuple->dst.protonum &&
		nf_inet_addr_cmp(&t->src.u3, &tuple->src.u3) &&
		t->src.u.all == tuple->src.u.all);
}


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Patrick McHardy4856.47%150.00%


Jozsef Kadlecsik3743.53%150.00%


Total85100.00%2100.00%






static int nf_nat_bysource_cmp(struct rhashtable_compare_arg *arg,
			       const void *obj)
{
	const struct nf_nat_conn_key *key = arg->key;
	const struct nf_conn *ct = obj;

	if (!same_src(ct, key->tuple) ||
	    !net_eq(nf_ct_net(ct), key->net) ||
	    !nf_ct_zone_equal(ct, key->zone, IP_CT_DIR_ORIGINAL))
		return 1;

	return 0;
}


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Total77100.00%2100.00%




static struct rhashtable_params nf_nat_bysource_params = {
	.head_offset = offsetof(struct nf_conn, nat_bysource),
	.obj_hashfn = nf_nat_bysource_hash,
	.obj_cmpfn = nf_nat_bysource_cmp,
	.nelem_hint = 256,
	.min_size = 1024,
};

/* Only called for SRC manip */


static int

find_appropriate_src(struct net *net,
		     const struct nf_conntrack_zone *zone,
		     const struct nf_nat_l3proto *l3proto,
		     const struct nf_nat_l4proto *l4proto,
		     const struct nf_conntrack_tuple *tuple,
		     struct nf_conntrack_tuple *result,
		     const struct nf_nat_range *range)
{
	const struct nf_conn *ct;
	struct nf_nat_conn_key key = {
		.net = net,
		.tuple = tuple,
		.zone = zone
	};
	struct rhlist_head *hl;

	hl = rhltable_lookup(&nf_nat_bysource_table, &key,
			     nf_nat_bysource_params);
	if (!hl)
		return 0;

	ct = container_of(hl, typeof(*ct), nat_bysource);

	nf_ct_invert_tuplepr(result,
			     &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
	result->dst = tuple->dst;

	return in_range(l3proto, l4proto, result, range);
}


Contributors
PersonTokensPropCommitsCommitProp
Jozsef Kadlecsik5939.60%110.00%


Florian Westphal5738.26%330.00%


Patrick McHardy2013.42%220.00%


Daniel Borkmann74.70%220.00%


Alexey Dobriyan53.36%110.00%


Jan Engelhardt10.67%110.00%


Total149100.00%10100.00%



/* For [FUTURE] fragmentation handling, we want the least-used
 * src-ip/dst-ip/proto triple.  Fairness doesn't come into it.  Thus
 * if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
 * 1-65535, we don't do pro-rata allocation based on ports; we choose
 * the ip with the lowest src-ip/dst-ip/proto usage.
 */


static void

find_best_ips_proto(const struct nf_conntrack_zone *zone,
		    struct nf_conntrack_tuple *tuple,
		    const struct nf_nat_range *range,
		    const struct nf_conn *ct,
		    enum nf_nat_manip_type maniptype)
{
	union nf_inet_addr *var_ipp;
	unsigned int i, max;
	/* Host order */
	u32 minip, maxip, j, dist;
	bool full_range;

	/* No IP mapping?  Do nothing. */
	if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
		return;

	if (maniptype == NF_NAT_MANIP_SRC)
		var_ipp = &tuple->src.u3;
	else
		var_ipp = &tuple->dst.u3;

	/* Fast path: only one choice. */
	if (nf_inet_addr_cmp(&range->min_addr, &range->max_addr)) {
		*var_ipp = range->min_addr;
		return;
	}

	if (nf_ct_l3num(ct) == NFPROTO_IPV4)
		max = sizeof(var_ipp->ip) / sizeof(u32) - 1;
	else
		max = sizeof(var_ipp->ip6) / sizeof(u32) - 1;

	/* Hashing source and destination IPs gives a fairly even
         * spread in practice (if there are a small number of IPs
         * involved, there usually aren't that many connections
         * anyway).  The consistency means that servers see the same
         * client coming from the same IP (some Internet Banking sites
         * like this), even across reboots.
         */
	j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3) / sizeof(u32),
		   range->flags & NF_NAT_RANGE_PERSISTENT ?
			0 : (__force u32)tuple->dst.u3.all[max] ^ zone->id);

	full_range = false;
	for (i = 0; i <= max; i++) {
		/* If first bytes of the address are at the maximum, use the
                 * distance. Otherwise use the full range.
                 */
		if (!full_range) {
			minip = ntohl((__force __be32)range->min_addr.all[i]);
			maxip = ntohl((__force __be32)range->max_addr.all[i]);
			dist  = maxip - minip + 1;
		} else {
			minip = 0;
			dist  = ~0;
		}

		var_ipp->all[i] = (__force __u32)
			htonl(minip + reciprocal_scale(j, dist));
		if (var_ipp->all[i] != range->max_addr.all[i])
			full_range = true;

		if (!(range->flags & NF_NAT_RANGE_PERSISTENT))
			j ^= (__force u32)tuple->dst.u3.all[i];
	}
}


Contributors
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Patrick McHardy23161.27%550.00%


Jozsef Kadlecsik12934.22%110.00%


Daniel Borkmann102.65%220.00%


Florian Westphal51.33%110.00%


Maximilian Engelhardt20.53%110.00%


Total377100.00%10100.00%



/* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
 * we change the source to map into the range. For NF_INET_PRE_ROUTING
 * and NF_INET_LOCAL_OUT, we change the destination to map into the
 * range. It might not be possible to get a unique tuple, but we try.
 * At worst (or if we race), we will end up with a final duplicate in
 * __ip_conntrack_confirm and drop the packet. */


static void

get_unique_tuple(struct nf_conntrack_tuple *tuple,
		 const struct nf_conntrack_tuple *orig_tuple,
		 const struct nf_nat_range *range,
		 struct nf_conn *ct,
		 enum nf_nat_manip_type maniptype)
{
	const struct nf_conntrack_zone *zone;
	const struct nf_nat_l3proto *l3proto;
	const struct nf_nat_l4proto *l4proto;
	struct net *net = nf_ct_net(ct);

	zone = nf_ct_zone(ct);

	rcu_read_lock();
	l3proto = __nf_nat_l3proto_find(orig_tuple->src.l3num);
	l4proto = __nf_nat_l4proto_find(orig_tuple->src.l3num,
					orig_tuple->dst.protonum);

	/* 1) If this srcip/proto/src-proto-part is currently mapped,
         * and that same mapping gives a unique tuple within the given
         * range, use that.
         *
         * This is only required for source (ie. NAT/masq) mappings.
         * So far, we don't do local source mappings, so multiple
         * manips not an issue.
         */
	if (maniptype == NF_NAT_MANIP_SRC &&
	    !(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
		/* try the original tuple first */
		if (in_range(l3proto, l4proto, orig_tuple, range)) {
			if (!nf_nat_used_tuple(orig_tuple, ct)) {
				*tuple = *orig_tuple;
				goto out;
			}
		} else if (find_appropriate_src(net, zone, l3proto, l4proto,
						orig_tuple, tuple, range)) {
			pr_debug("get_unique_tuple: Found current src map\n");
			if (!nf_nat_used_tuple(tuple, ct))
				goto out;
		}
	}

	/* 2) Select the least-used IP/proto combination in the given range */
	*tuple = *orig_tuple;
	find_best_ips_proto(zone, tuple, range, ct, maniptype);

	/* 3) The per-protocol part of the manip is made to map into
         * the range to make a unique tuple.
         */

	/* Only bother mapping if it's not already in range and unique */
	if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
		if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
			if (l4proto->in_range(tuple, maniptype,
					      &range->min_proto,
					      &range->max_proto) &&
			    (range->min_proto.all == range->max_proto.all ||
			     !nf_nat_used_tuple(tuple, ct)))
				goto out;
		} else if (!nf_nat_used_tuple(tuple, ct)) {
			goto out;
		}
	}

	/* Last change: get protocol to try to obtain unique tuple. */
	l4proto->unique_tuple(l3proto, tuple, range, maniptype, ct);
out:
	rcu_read_unlock();
}


Contributors
PersonTokensPropCommitsCommitProp
Jozsef Kadlecsik13241.12%17.14%


Patrick McHardy9128.35%535.71%


Changli Gao7021.81%428.57%


Alexey Dobriyan123.74%17.14%


Daniel Borkmann103.12%214.29%


Eric Leblond61.87%17.14%


Total321100.00%14100.00%






struct nf_conn_nat *nf_ct_nat_ext_add(struct nf_conn *ct)
{
	struct nf_conn_nat *nat = nfct_nat(ct);
	if (nat)
		return nat;

	if (!nf_ct_is_confirmed(ct))
		nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);

	return nat;
}

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Total51100.00%1100.00%




EXPORT_SYMBOL_GPL(nf_ct_nat_ext_add);



unsigned int

nf_nat_setup_info(struct nf_conn *ct,
		  const struct nf_nat_range *range,
		  enum nf_nat_manip_type maniptype)
{
	struct nf_conntrack_tuple curr_tuple, new_tuple;
	struct nf_conn_nat *nat;

	/* nat helper or nfctnetlink also setup binding */
	nat = nf_ct_nat_ext_add(ct);
	if (nat == NULL)
		return NF_ACCEPT;

	NF_CT_ASSERT(maniptype == NF_NAT_MANIP_SRC ||
		     maniptype == NF_NAT_MANIP_DST);
	BUG_ON(nf_nat_initialized(ct, maniptype));

	/* What we've got will look like inverse of reply. Normally
         * this is what is in the conntrack, except for prior
         * manipulations (future optimization: if num_manips == 0,
         * orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
         */
	nf_ct_invert_tuplepr(&curr_tuple,
			     &ct->tuplehash[IP_CT_DIR_REPLY].tuple);

	get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);

	if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) {
		struct nf_conntrack_tuple reply;

		/* Alter conntrack table so will recognize replies. */
		nf_ct_invert_tuplepr(&reply, &new_tuple);
		nf_conntrack_alter_reply(ct, &reply);

		/* Non-atomic: we own this at the moment. */
		if (maniptype == NF_NAT_MANIP_SRC)
			ct->status |= IPS_SRC_NAT;
		else
			ct->status |= IPS_DST_NAT;

		if (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;
}

Contributors
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Jozsef Kadlecsik16460.74%17.14%


Florian Westphal5420.00%428.57%


Patrick McHardy238.52%428.57%


Yasuyuki Kozakai165.93%17.14%


Gao Feng72.59%17.14%


Changli Gao62.22%321.43%


Total270100.00%14100.00%




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);
}


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Pablo Neira Ayuso85100.00%2100.00%


Total85100.00%2100.00%





unsigned int

nf_nat_alloc_null_binding(struct nf_conn *ct, unsigned int hooknum)
{
	return __nf_nat_alloc_null_binding(ct, HOOK2MANIP(hooknum));
}

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Total26100.00%2100.00%




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;
}

Contributors
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Jozsef Kadlecsik12472.94%125.00%


Patrick McHardy4425.88%250.00%


Herbert Xu21.18%125.00%


Total170100.00%4100.00%




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;
	struct nf_conn_nat *nat = nfct_nat(i);

	if (!nat)
		return 0;

	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;
}


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Patrick McHardy4248.28%133.33%


Jozsef Kadlecsik3944.83%133.33%


Florian Westphal66.90%133.33%


Total87100.00%3100.00%






static int nf_nat_proto_clean(struct nf_conn *ct, void *data)
{
	struct nf_conn_nat *nat = nfct_nat(ct);

	if (nf_nat_proto_remove(ct, data))
		return 1;

	if (!nat)
		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.
         */
	ct->status &= ~IPS_NAT_DONE_MASK;
	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;
}


Contributors
PersonTokensPropCommitsCommitProp
Florian Westphal70100.00%3100.00%


Total70100.00%3100.00%






static void nf_nat_l4proto_clean(u8 l3proto, u8 l4proto)
{
	struct nf_nat_proto_clean clean = {
		.l3proto = l3proto,
		.l4proto = l4proto,
        };
	struct net *net;

	rtnl_lock();
	for_each_net(net)
		nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean, 0, 0);
	rtnl_unlock();
}


Contributors
PersonTokensPropCommitsCommitProp
Patrick McHardy4782.46%120.00%


Florian Westphal58.77%240.00%


Julian Anastasov35.26%120.00%


Jozsef Kadlecsik23.51%120.00%


Total57100.00%5100.00%






static void nf_nat_l3proto_clean(u8 l3proto)
{
	struct nf_nat_proto_clean clean = {
		.l3proto = l3proto,
        };
	struct net *net;

	rtnl_lock();

	for_each_net(net)
		nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean, 0, 0);
	rtnl_unlock();
}


Contributors
PersonTokensPropCommitsCommitProp
Patrick McHardy4183.67%125.00%


Florian Westphal510.20%250.00%


Jozsef Kadlecsik36.12%125.00%


Total49100.00%4100.00%



/* 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;
}

Contributors
PersonTokensPropCommitsCommitProp
Patrick McHardy15488.51%150.00%


Jozsef Kadlecsik2011.49%150.00%


Total174100.00%2100.00%




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);
}

Contributors
PersonTokensPropCommitsCommitProp
Patrick McHardy4379.63%150.00%


Jozsef Kadlecsik1120.37%150.00%


Total54100.00%2100.00%




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],