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Commit 1f55236b authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso
Browse files

netfilter: nf_nat: move common nat code to nat core 



Copy-pasted, both l3 helpers almost use same code here.
Split out the common part into an 'inet' helper.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent b9ccc07e

include/net/netfilter/nf_nat_core.h

+7 −0
Original line number Diff line number Diff line
@@ -11,6 +11,13 @@ 
unsigned int nf_nat_packet(struct nf_conn *ct, enum ip_conntrack_info ctinfo,

			   unsigned int hooknum, struct sk_buff *skb);



unsigned int

nf_nat_inet_fn(void *priv, struct sk_buff *skb,

	       const struct nf_hook_state *state,

	       unsigned int (*do_chain)(void *priv,

					struct sk_buff *skb,

					const struct nf_hook_state *state));



int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family);



static inline int nf_nat_initialized(struct nf_conn *ct,

net/ipv4/netfilter/nf_nat_l3proto_ipv4.c

+2 −53
Original line number Diff line number Diff line
@@ -250,24 +250,12 @@ nf_nat_ipv4_fn(void *priv, struct sk_buff *skb, 
{

	struct nf_conn *ct;

	enum ip_conntrack_info ctinfo;

	struct nf_conn_nat *nat;

	/* maniptype == SRC for postrouting. */

	enum nf_nat_manip_type maniptype = HOOK2MANIP(state->hook);



	ct = nf_ct_get(skb, &ctinfo);

	/* Can't track?  It's not due to stress, or conntrack would

	 * have dropped it.  Hence it's the user's responsibilty to

	 * packet filter it out, or implement conntrack/NAT for that

	 * protocol. 8) --RR

	 */

	if (!ct)

		return NF_ACCEPT;



	nat = nfct_nat(ct);



	switch (ctinfo) {

	case IP_CT_RELATED:

	case IP_CT_RELATED_REPLY:

	if (ctinfo == IP_CT_RELATED || ctinfo == IP_CT_RELATED_REPLY) {

		if (ip_hdr(skb)->protocol == IPPROTO_ICMP) {

			if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,

							   state->hook))
@@ -275,48 +263,9 @@ nf_nat_ipv4_fn(void *priv, struct sk_buff *skb, 
			else

				return NF_ACCEPT;

		}

		/* Only ICMPs can be IP_CT_IS_REPLY: */

		/* fall through */

	case IP_CT_NEW:

		/* Seen it before?  This can happen for loopback, retrans,

		 * or local packets.

		 */

		if (!nf_nat_initialized(ct, maniptype)) {

			unsigned int ret;



			ret = do_chain(priv, skb, state);

			if (ret != NF_ACCEPT)

				return ret;



			if (nf_nat_initialized(ct, HOOK2MANIP(state->hook)))

				break;



			ret = nf_nat_alloc_null_binding(ct, state->hook);

			if (ret != NF_ACCEPT)

				return ret;

		} else {

			pr_debug("Already setup manip %s for ct %p\n",

				 maniptype == NF_NAT_MANIP_SRC ? "SRC" : "DST",

				 ct);

			if (nf_nat_oif_changed(state->hook, ctinfo, nat,

					       state->out))

				goto oif_changed;

	}

		break;



	default:

		/* ESTABLISHED */

		WARN_ON(ctinfo != IP_CT_ESTABLISHED &&

			ctinfo != IP_CT_ESTABLISHED_REPLY);

		if (nf_nat_oif_changed(state->hook, ctinfo, nat, state->out))

			goto oif_changed;

	}



	return nf_nat_packet(ct, ctinfo, state->hook, skb);



oif_changed:

	nf_ct_kill_acct(ct, ctinfo, skb);

	return NF_DROP;

	return nf_nat_inet_fn(priv, skb, state, do_chain);

}

EXPORT_SYMBOL_GPL(nf_nat_ipv4_fn);

net/ipv6/netfilter/nf_nat_l3proto_ipv6.c

+2 −46
Original line number Diff line number Diff line
@@ -261,8 +261,6 @@ nf_nat_ipv6_fn(void *priv, struct sk_buff *skb, 
{

	struct nf_conn *ct;

	enum ip_conntrack_info ctinfo;

	struct nf_conn_nat *nat;

	enum nf_nat_manip_type maniptype = HOOK2MANIP(state->hook);

	__be16 frag_off;

	int hdrlen;

	u8 nexthdr;
@@ -276,11 +274,7 @@ nf_nat_ipv6_fn(void *priv, struct sk_buff *skb, 
	if (!ct)

		return NF_ACCEPT;



	nat = nfct_nat(ct);



	switch (ctinfo) {

	case IP_CT_RELATED:

	case IP_CT_RELATED_REPLY:

	if (ctinfo == IP_CT_RELATED || ctinfo == IP_CT_RELATED_REPLY) {

		nexthdr = ipv6_hdr(skb)->nexthdr;

		hdrlen = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),

					  &nexthdr, &frag_off);
@@ -293,47 +287,9 @@ nf_nat_ipv6_fn(void *priv, struct sk_buff *skb, 
			else

				return NF_ACCEPT;

		}

		/* Only ICMPs can be IP_CT_IS_REPLY: */

		/* fall through */

	case IP_CT_NEW:

		/* Seen it before?  This can happen for loopback, retrans,

		 * or local packets.

		 */

		if (!nf_nat_initialized(ct, maniptype)) {

			unsigned int ret;



			ret = do_chain(priv, skb, state);

			if (ret != NF_ACCEPT)

				return ret;



			if (nf_nat_initialized(ct, HOOK2MANIP(state->hook)))

				break;



			ret = nf_nat_alloc_null_binding(ct, state->hook);

			if (ret != NF_ACCEPT)

				return ret;

		} else {

			pr_debug("Already setup manip %s for ct %p\n",

				 maniptype == NF_NAT_MANIP_SRC ? "SRC" : "DST",

				 ct);

			if (nf_nat_oif_changed(state->hook, ctinfo, nat, state->out))

				goto oif_changed;

		}

		break;



	default:

		/* ESTABLISHED */

		WARN_ON(ctinfo != IP_CT_ESTABLISHED &&

			ctinfo != IP_CT_ESTABLISHED_REPLY);

		if (nf_nat_oif_changed(state->hook, ctinfo, nat, state->out))

			goto oif_changed;

	}



	return nf_nat_packet(ct, ctinfo, state->hook, skb);



oif_changed:

	nf_ct_kill_acct(ct, ctinfo, skb);

	return NF_DROP;

	return nf_nat_inet_fn(priv, skb, state, do_chain);

}

EXPORT_SYMBOL_GPL(nf_nat_ipv6_fn);

net/netfilter/nf_nat_core.c

+70 −0
Original line number Diff line number Diff line
@@ -513,6 +513,76 @@ unsigned int nf_nat_packet(struct nf_conn *ct, 
}

EXPORT_SYMBOL_GPL(nf_nat_packet);



unsigned int

nf_nat_inet_fn(void *priv, struct sk_buff *skb,

	       const struct nf_hook_state *state,

	       unsigned int (*do_chain)(void *priv,

					struct sk_buff *skb,

					const struct nf_hook_state *state))

{

	struct nf_conn *ct;

	enum ip_conntrack_info ctinfo;

	struct nf_conn_nat *nat;

	/* maniptype == SRC for postrouting. */

	enum nf_nat_manip_type maniptype = HOOK2MANIP(state->hook);



	ct = nf_ct_get(skb, &ctinfo);

	/* Can't track?  It's not due to stress, or conntrack would

	 * have dropped it.  Hence it's the user's responsibilty to

	 * packet filter it out, or implement conntrack/NAT for that

	 * protocol. 8) --RR

	 */

	if (!ct)

		return NF_ACCEPT;



	nat = nfct_nat(ct);



	switch (ctinfo) {

	case IP_CT_RELATED:

	case IP_CT_RELATED_REPLY:

		/* Only ICMPs can be IP_CT_IS_REPLY.  Fallthrough */

	case IP_CT_NEW:

		/* Seen it before?  This can happen for loopback, retrans,

		 * or local packets.

		 */

		if (!nf_nat_initialized(ct, maniptype)) {

			unsigned int ret;



			ret = do_chain(priv, skb, state);

			if (ret != NF_ACCEPT)

				return ret;



			if (nf_nat_initialized(ct, HOOK2MANIP(state->hook)))

				break;



			ret = nf_nat_alloc_null_binding(ct, state->hook);

			if (ret != NF_ACCEPT)

				return ret;

		} else {

			pr_debug("Already setup manip %s for ct %p (status bits 0x%lx)\n",

				 maniptype == NF_NAT_MANIP_SRC ? "SRC" : "DST",

				 ct, ct->status);

			if (nf_nat_oif_changed(state->hook, ctinfo, nat,

					       state->out))

				goto oif_changed;

		}

		break;

	default:

		/* ESTABLISHED */

		WARN_ON(ctinfo != IP_CT_ESTABLISHED &&

			ctinfo != IP_CT_ESTABLISHED_REPLY);

		if (nf_nat_oif_changed(state->hook, ctinfo, nat, state->out))

			goto oif_changed;

	}



	return nf_nat_packet(ct, ctinfo, state->hook, skb);



oif_changed:

	nf_ct_kill_acct(ct, ctinfo, skb);

	return NF_DROP;

}

EXPORT_SYMBOL_GPL(nf_nat_inet_fn);



struct nf_nat_proto_clean {

	u8	l3proto;

	u8	l4proto;