Commit c0c3ab63 authored by Xin Long's avatar Xin Long Committed by Jakub Kicinski
Browse files

net: create nf_conntrack_ovs for ovs and tc use 



Similar to nf_nat_ovs created by Commit ebddb140 ("net: move the
nat function to nf_nat_ovs for ovs and tc"), this patch is to create
nf_conntrack_ovs to get these functions shared by OVS and TC only.

There are nf_ct_helper() and nf_ct_add_helper() from nf_conntrak_helper
in this patch, and will be more in the following patches.

Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
Reviewed-by: default avatarSimon Horman <simon.horman@corigine.com>
Reviewed-by: default avatarAaron Conole <aconole@redhat.com>
Acked-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 025a785f

net/netfilter/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -189,6 +189,9 @@ config NF_CONNTRACK_LABELS 
	  to connection tracking entries.  It can be used with xtables connlabel

	  match and the nftables ct expression.



config NF_CONNTRACK_OVS

	bool



config NF_CT_PROTO_DCCP

	bool 'DCCP protocol connection tracking support'

	depends on NETFILTER_ADVANCED

net/netfilter/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ nf_conntrack-$(CONFIG_NF_CONNTRACK_TIMEOUT) += nf_conntrack_timeout.o 
nf_conntrack-$(CONFIG_NF_CONNTRACK_TIMESTAMP) += nf_conntrack_timestamp.o

nf_conntrack-$(CONFIG_NF_CONNTRACK_EVENTS) += nf_conntrack_ecache.o

nf_conntrack-$(CONFIG_NF_CONNTRACK_LABELS) += nf_conntrack_labels.o

nf_conntrack-$(CONFIG_NF_CONNTRACK_OVS) += nf_conntrack_ovs.o

nf_conntrack-$(CONFIG_NF_CT_PROTO_DCCP) += nf_conntrack_proto_dccp.o

nf_conntrack-$(CONFIG_NF_CT_PROTO_SCTP) += nf_conntrack_proto_sctp.o

nf_conntrack-$(CONFIG_NF_CT_PROTO_GRE) += nf_conntrack_proto_gre.o

net/netfilter/nf_conntrack_helper.c

+0 −98
Original line number Diff line number Diff line
@@ -242,104 +242,6 @@ int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl, 
}

EXPORT_SYMBOL_GPL(__nf_ct_try_assign_helper);



/* 'skb' should already be pulled to nh_ofs. */

int nf_ct_helper(struct sk_buff *skb, struct nf_conn *ct,

		 enum ip_conntrack_info ctinfo, u16 proto)

{

	const struct nf_conntrack_helper *helper;

	const struct nf_conn_help *help;

	unsigned int protoff;

	int err;



	if (ctinfo == IP_CT_RELATED_REPLY)

		return NF_ACCEPT;



	help = nfct_help(ct);

	if (!help)

		return NF_ACCEPT;



	helper = rcu_dereference(help->helper);

	if (!helper)

		return NF_ACCEPT;



	if (helper->tuple.src.l3num != NFPROTO_UNSPEC &&

	    helper->tuple.src.l3num != proto)

		return NF_ACCEPT;



	switch (proto) {

	case NFPROTO_IPV4:

		protoff = ip_hdrlen(skb);

		proto = ip_hdr(skb)->protocol;

		break;

	case NFPROTO_IPV6: {

		u8 nexthdr = ipv6_hdr(skb)->nexthdr;

		__be16 frag_off;

		int ofs;



		ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,

				       &frag_off);

		if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {

			pr_debug("proto header not found\n");

			return NF_ACCEPT;

		}

		protoff = ofs;

		proto = nexthdr;

		break;

	}

	default:

		WARN_ONCE(1, "helper invoked on non-IP family!");

		return NF_DROP;

	}



	if (helper->tuple.dst.protonum != proto)

		return NF_ACCEPT;



	err = helper->help(skb, protoff, ct, ctinfo);

	if (err != NF_ACCEPT)

		return err;



	/* Adjust seqs after helper.  This is needed due to some helpers (e.g.,

	 * FTP with NAT) adusting the TCP payload size when mangling IP

	 * addresses and/or port numbers in the text-based control connection.

	 */

	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&

	    !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))

		return NF_DROP;

	return NF_ACCEPT;

}

EXPORT_SYMBOL_GPL(nf_ct_helper);



int nf_ct_add_helper(struct nf_conn *ct, const char *name, u8 family,

		     u8 proto, bool nat, struct nf_conntrack_helper **hp)

{

	struct nf_conntrack_helper *helper;

	struct nf_conn_help *help;

	int ret = 0;



	helper = nf_conntrack_helper_try_module_get(name, family, proto);

	if (!helper)

		return -EINVAL;



	help = nf_ct_helper_ext_add(ct, GFP_KERNEL);

	if (!help) {

		nf_conntrack_helper_put(helper);

		return -ENOMEM;

	}

#if IS_ENABLED(CONFIG_NF_NAT)

	if (nat) {

		ret = nf_nat_helper_try_module_get(name, family, proto);

		if (ret) {

			nf_conntrack_helper_put(helper);

			return ret;

		}

	}

#endif

	rcu_assign_pointer(help->helper, helper);

	*hp = helper;

	return ret;

}

EXPORT_SYMBOL_GPL(nf_ct_add_helper);



/* appropriate ct lock protecting must be taken by caller */

static int unhelp(struct nf_conn *ct, void *me)

{

net/netfilter/nf_conntrack_ovs.c

0 → 100644
+104 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/* Support ct functions for openvswitch and used by OVS and TC conntrack. */



#include <net/netfilter/nf_conntrack_helper.h>

#include <net/netfilter/nf_conntrack_seqadj.h>

#include <net/ip.h>



/* 'skb' should already be pulled to nh_ofs. */

int nf_ct_helper(struct sk_buff *skb, struct nf_conn *ct,

		 enum ip_conntrack_info ctinfo, u16 proto)

{

	const struct nf_conntrack_helper *helper;

	const struct nf_conn_help *help;

	unsigned int protoff;

	int err;



	if (ctinfo == IP_CT_RELATED_REPLY)

		return NF_ACCEPT;



	help = nfct_help(ct);

	if (!help)

		return NF_ACCEPT;



	helper = rcu_dereference(help->helper);

	if (!helper)

		return NF_ACCEPT;



	if (helper->tuple.src.l3num != NFPROTO_UNSPEC &&

	    helper->tuple.src.l3num != proto)

		return NF_ACCEPT;



	switch (proto) {

	case NFPROTO_IPV4:

		protoff = ip_hdrlen(skb);

		proto = ip_hdr(skb)->protocol;

		break;

	case NFPROTO_IPV6: {

		u8 nexthdr = ipv6_hdr(skb)->nexthdr;

		__be16 frag_off;

		int ofs;



		ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,

				       &frag_off);

		if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {

			pr_debug("proto header not found\n");

			return NF_ACCEPT;

		}

		protoff = ofs;

		proto = nexthdr;

		break;

	}

	default:

		WARN_ONCE(1, "helper invoked on non-IP family!");

		return NF_DROP;

	}



	if (helper->tuple.dst.protonum != proto)

		return NF_ACCEPT;



	err = helper->help(skb, protoff, ct, ctinfo);

	if (err != NF_ACCEPT)

		return err;



	/* Adjust seqs after helper.  This is needed due to some helpers (e.g.,

	 * FTP with NAT) adusting the TCP payload size when mangling IP

	 * addresses and/or port numbers in the text-based control connection.

	 */

	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&

	    !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))

		return NF_DROP;

	return NF_ACCEPT;

}

EXPORT_SYMBOL_GPL(nf_ct_helper);



int nf_ct_add_helper(struct nf_conn *ct, const char *name, u8 family,

		     u8 proto, bool nat, struct nf_conntrack_helper **hp)

{

	struct nf_conntrack_helper *helper;

	struct nf_conn_help *help;

	int ret = 0;



	helper = nf_conntrack_helper_try_module_get(name, family, proto);

	if (!helper)

		return -EINVAL;



	help = nf_ct_helper_ext_add(ct, GFP_KERNEL);

	if (!help) {

		nf_conntrack_helper_put(helper);

		return -ENOMEM;

	}

#if IS_ENABLED(CONFIG_NF_NAT)

	if (nat) {

		ret = nf_nat_helper_try_module_get(name, family, proto);

		if (ret) {

			nf_conntrack_helper_put(helper);

			return ret;

		}

	}

#endif

	rcu_assign_pointer(help->helper, helper);

	*hp = helper;

	return ret;

}

EXPORT_SYMBOL_GPL(nf_ct_add_helper);

net/openvswitch/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ config OPENVSWITCH 
	select NET_MPLS_GSO

	select DST_CACHE

	select NET_NSH

	select NF_CONNTRACK_OVS if NF_CONNTRACK

	select NF_NAT_OVS if NF_NAT

	help

	  Open vSwitch is a multilayer Ethernet switch targeted at virtualized