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Commit b7bd1809 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
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netfilter: nfnetlink_queue: get rid of nfnetlink_queue_ct.c 



The original intention was to avoid dependencies between nfnetlink_queue and
conntrack without ifdef pollution. However, we can achieve this by moving the
conntrack dependent code into ctnetlink and keep some glue code to access the
nfq_ct indirection from nfqueue.

After this patch, the nfq_ct indirection is always compiled in the netfilter
core to avoid polluting nfqueue with ifdefs. Thus, if nf_conntrack is not
compiled this results in only 8-bytes of memory waste in x86_64.

This patch also adds ctnetlink_nfqueue_seqadj() to avoid that the nf_conn
structure layout if exposed to nf_queue, which creates another dependency with
nf_conntrack at compilation time.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent e96f78ab

include/linux/netfilter.h

+8 −4
Original line number Diff line number Diff line
@@ -369,14 +369,21 @@ nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) 
extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;

void nf_ct_attach(struct sk_buff *, const struct sk_buff *);

extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;

#else

static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}

#endif



struct nf_conn;

enum ip_conntrack_info;

struct nlattr;



struct nfq_ct_hook {

	struct nf_conn *(*get_ct)(struct sk_buff *skb,

				  enum ip_conntrack_info *ctinfo);

	size_t (*build_size)(const struct nf_conn *ct);

	int (*build)(struct sk_buff *skb, struct nf_conn *ct);

	int (*build)(struct sk_buff *skb, struct nf_conn *ct,

		     enum ip_conntrack_info ctinfo,

		     u_int16_t ct_attr, u_int16_t ct_info_attr);

	int (*parse)(const struct nlattr *attr, struct nf_conn *ct);

	int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,

			     u32 portid, u32 report);
@@ -384,9 +391,6 @@ struct nfq_ct_hook { 
			   enum ip_conntrack_info ctinfo, s32 off);

};

extern struct nfq_ct_hook __rcu *nfq_ct_hook;

#else

static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}

#endif



/**

 * nf_skb_duplicated - TEE target has sent a packet

include/net/netfilter/nfnetlink_queue.h

deleted100644 → 0
+0 −51
Original line number Diff line number Diff line 
#ifndef _NET_NFNL_QUEUE_H_

#define _NET_NFNL_QUEUE_H_



#include <linux/netfilter/nf_conntrack_common.h>



struct nf_conn;



#ifdef CONFIG_NETFILTER_NETLINK_QUEUE_CT

struct nf_conn *nfqnl_ct_get(struct sk_buff *entskb, size_t *size,

			     enum ip_conntrack_info *ctinfo);

struct nf_conn *nfqnl_ct_parse(const struct sk_buff *skb,

			       const struct nlattr *attr,

			       enum ip_conntrack_info *ctinfo);

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

		 enum ip_conntrack_info ctinfo);

void nfqnl_ct_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,

			 enum ip_conntrack_info ctinfo, int diff);

int nfqnl_attach_expect(struct nf_conn *ct, const struct nlattr *attr,

			u32 portid, u32 report);

#else

inline struct nf_conn *

nfqnl_ct_get(struct sk_buff *entskb, size_t *size, enum ip_conntrack_info *ctinfo)

{

	return NULL;

}



inline struct nf_conn *nfqnl_ct_parse(const struct sk_buff *skb,

				      const struct nlattr *attr,

				      enum ip_conntrack_info *ctinfo)

{

	return NULL;

}



inline int

nfqnl_ct_put(struct sk_buff *skb, struct nf_conn *ct, enum ip_conntrack_info ctinfo)

{

	return 0;

}



inline void nfqnl_ct_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,

				enum ip_conntrack_info ctinfo, int diff)

{

}



inline int nfqnl_attach_expect(struct nf_conn *ct, const struct nlattr *attr,

			       u32 portid, u32 report)

{

	return 0;

}

#endif /* NF_CONNTRACK */

#endif

net/netfilter/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -11,7 +11,6 @@ obj-$(CONFIG_NETFILTER) = netfilter.o 
obj-$(CONFIG_NETFILTER_NETLINK) += nfnetlink.o

obj-$(CONFIG_NETFILTER_NETLINK_ACCT) += nfnetlink_acct.o

nfnetlink_queue-y := nfnetlink_queue_core.o

nfnetlink_queue-$(CONFIG_NETFILTER_NETLINK_QUEUE_CT) += nfnetlink_queue_ct.o

obj-$(CONFIG_NETFILTER_NETLINK_QUEUE) += nfnetlink_queue.o

obj-$(CONFIG_NETFILTER_NETLINK_LOG) += nfnetlink_log.o

net/netfilter/core.c

+6 −3
Original line number Diff line number Diff line
@@ -348,6 +348,12 @@ int skb_make_writable(struct sk_buff *skb, unsigned int writable_len) 
}

EXPORT_SYMBOL(skb_make_writable);



/* This needs to be compiled in any case to avoid dependencies between the

 * nfnetlink_queue code and nf_conntrack.

 */

struct nfq_ct_hook __rcu *nfq_ct_hook __read_mostly;

EXPORT_SYMBOL_GPL(nfq_ct_hook);



#if IS_ENABLED(CONFIG_NF_CONNTRACK)

/* This does not belong here, but locally generated errors need it if connection

   tracking in use: without this, connection may not be in hash table, and hence
@@ -385,9 +391,6 @@ void nf_conntrack_destroy(struct nf_conntrack *nfct) 
}

EXPORT_SYMBOL(nf_conntrack_destroy);



struct nfq_ct_hook __rcu *nfq_ct_hook __read_mostly;

EXPORT_SYMBOL_GPL(nfq_ct_hook);



/* Built-in default zone used e.g. by modules. */

const struct nf_conntrack_zone nf_ct_zone_dflt = {

	.id	= NF_CT_DEFAULT_ZONE_ID,

net/netfilter/nf_conntrack_netlink.c

+49 −3
Original line number Diff line number Diff line
@@ -2162,8 +2162,19 @@ ctnetlink_nfqueue_build_size(const struct nf_conn *ct) 
	       ;

}



static int

ctnetlink_nfqueue_build(struct sk_buff *skb, struct nf_conn *ct)

static struct nf_conn *ctnetlink_nfqueue_get_ct(struct sk_buff *skb,

						enum ip_conntrack_info *ctinfo)

{

	struct nf_conn *ct;



	ct = nf_ct_get(skb, ctinfo);

	if (ct && nf_ct_is_untracked(ct))

		ct = NULL;



	return ct;

}



static int __ctnetlink_nfqueue_build(struct sk_buff *skb, struct nf_conn *ct)

{

	const struct nf_conntrack_zone *zone;

	struct nlattr *nest_parms;
@@ -2235,6 +2246,31 @@ ctnetlink_nfqueue_build(struct sk_buff *skb, struct nf_conn *ct) 
	return -ENOSPC;

}



static int

ctnetlink_nfqueue_build(struct sk_buff *skb, struct nf_conn *ct,

			enum ip_conntrack_info ctinfo,

			u_int16_t ct_attr, u_int16_t ct_info_attr)

{

	struct nlattr *nest_parms;



	nest_parms = nla_nest_start(skb, ct_attr | NLA_F_NESTED);

	if (!nest_parms)

		goto nla_put_failure;



	if (__ctnetlink_nfqueue_build(skb, ct) < 0)

		goto nla_put_failure;



	nla_nest_end(skb, nest_parms);



	if (nla_put_be32(skb, ct_info_attr, htonl(ctinfo)))

		goto nla_put_failure;



	return 0;



nla_put_failure:

	return -ENOSPC;

}



static int

ctnetlink_nfqueue_parse_ct(const struct nlattr *cda[], struct nf_conn *ct)

{
@@ -2350,12 +2386,22 @@ ctnetlink_nfqueue_attach_expect(const struct nlattr *attr, struct nf_conn *ct, 
	return 0;

}



static void ctnetlink_nfqueue_seqadj(struct sk_buff *skb, struct nf_conn *ct,

				     enum ip_conntrack_info ctinfo, int diff)

{

	if (!(ct->status & IPS_NAT_MASK))

		return;



	nf_ct_tcp_seqadj_set(skb, ct, ctinfo, diff);

}



static struct nfq_ct_hook ctnetlink_nfqueue_hook = {

	.get_ct		= ctnetlink_nfqueue_get_ct,

	.build_size	= ctnetlink_nfqueue_build_size,

	.build		= ctnetlink_nfqueue_build,

	.parse		= ctnetlink_nfqueue_parse,

	.attach_expect	= ctnetlink_nfqueue_attach_expect,

	.seq_adjust	= nf_ct_tcp_seqadj_set,

	.seq_adjust	= ctnetlink_nfqueue_seqadj,

};

#endif /* CONFIG_NETFILTER_NETLINK_QUEUE_CT */