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netfilter: nfnetlink_queue: get rid of nfnetlink_queue_ct.c

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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: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2015-09-30 22:53:44 +01:00
parent e96f78ab27
commit b7bd1809e0
7 changed files with 103 additions and 187 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
include/linux/netfilter.h
View File

@ -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

51
include/net/netfilter/nfnetlink_queue.h
View File

@ -1,51 +0,0 @@
#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

1
net/netfilter/Makefile
View File

@ -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

9
net/netfilter/core.c
View File

@ -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,

52
net/netfilter/nf_conntrack_netlink.c
View File

@ -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 @@ nla_put_failure:
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 */

52
net/netfilter/nfnetlink_queue_core.c
View File

@ -28,12 +28,12 @@
#include <linux/netfilter_bridge.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_queue.h>
#include <linux/netfilter/nf_conntrack_common.h>
#include <linux/list.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <net/netfilter/nf_queue.h>
#include <net/netns/generic.h>
#include <net/netfilter/nfnetlink_queue.h>
#include <linux/atomic.h>
@ -313,6 +313,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
struct net_device *outdev;
struct nf_conn *ct = NULL;
enum ip_conntrack_info uninitialized_var(ctinfo);
struct nfq_ct_hook *nfq_ct;
bool csum_verify;
char *secdata = NULL;
u32 seclen = 0;
@ -364,8 +365,14 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
break;
}
if (queue->flags & NFQA_CFG_F_CONNTRACK)
ct = nfqnl_ct_get(entskb, &size, &ctinfo);
if (queue->flags & NFQA_CFG_F_CONNTRACK) {
nfq_ct = rcu_dereference(nfq_ct_hook);
if (nfq_ct != NULL) {
ct = nfq_ct->get_ct(entskb, &ctinfo);
if (ct != NULL)
size += nfq_ct->build_size(ct);
}
}
if (queue->flags & NFQA_CFG_F_UID_GID) {
size += (nla_total_size(sizeof(u_int32_t)) /* uid */
@ -508,7 +515,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
goto nla_put_failure;
if (ct && nfqnl_ct_put(skb, ct, ctinfo) < 0)
if (ct && nfq_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
goto nla_put_failure;
if (cap_len > data_len &&
@ -1001,6 +1008,28 @@ nfqnl_recv_verdict_batch(struct sock *ctnl, struct sk_buff *skb,
return 0;
}
static struct nf_conn *nfqnl_ct_parse(struct nfq_ct_hook *nfq_ct,
const struct nlmsghdr *nlh,
const struct nlattr * const nfqa[],
struct nf_queue_entry *entry,
enum ip_conntrack_info *ctinfo)
{
struct nf_conn *ct;
ct = nfq_ct->get_ct(entry->skb, ctinfo);
if (ct == NULL)
return NULL;
if (nfq_ct->parse(nfqa[NFQA_CT], ct) < 0)
return NULL;
if (nfqa[NFQA_EXP])
nfq_ct->attach_expect(nfqa[NFQA_EXP], ct,
NETLINK_CB(entry->skb).portid,
nlmsg_report(nlh));
return ct;
}
static int
nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
const struct nlmsghdr *nlh,
@ -1014,6 +1043,7 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
unsigned int verdict;
struct nf_queue_entry *entry;
enum ip_conntrack_info uninitialized_var(ctinfo);
struct nfq_ct_hook *nfq_ct;
struct nf_conn *ct = NULL;
struct net *net = sock_net(ctnl);
@ -1037,12 +1067,10 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
return -ENOENT;
if (nfqa[NFQA_CT]) {
ct = nfqnl_ct_parse(entry->skb, nfqa[NFQA_CT], &ctinfo);
if (ct && nfqa[NFQA_EXP]) {
nfqnl_attach_expect(ct, nfqa[NFQA_EXP],
NETLINK_CB(skb).portid,
nlmsg_report(nlh));
}
/* rcu lock already held from nfnl->call_rcu. */
nfq_ct = rcu_dereference(nfq_ct_hook);
if (nfq_ct != NULL)
ct = nfqnl_ct_parse(nfq_ct, nlh, nfqa, entry, &ctinfo);
}
if (nfqa[NFQA_PAYLOAD]) {
@ -1053,8 +1081,8 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
payload_len, entry, diff) < 0)
verdict = NF_DROP;
if (ct)
nfqnl_ct_seq_adjust(entry->skb, ct, ctinfo, diff);
if (ct && diff)
nfq_ct->seq_adjust(entry->skb, ct, ctinfo, diff);
}
if (nfqa[NFQA_MARK])

113
net/netfilter/nfnetlink_queue_ct.c
View File

@ -1,113 +0,0 @@
/*
* (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
*
* 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/skbuff.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_queue.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nfnetlink_queue.h>
struct nf_conn *nfqnl_ct_get(struct sk_buff *entskb, size_t *size,
enum ip_conntrack_info *ctinfo)
{
struct nfq_ct_hook *nfq_ct;
struct nf_conn *ct;
/* rcu_read_lock()ed by __nf_queue already. */
nfq_ct = rcu_dereference(nfq_ct_hook);
if (nfq_ct == NULL)
return NULL;
ct = nf_ct_get(entskb, ctinfo);
if (ct) {
if (!nf_ct_is_untracked(ct))
*size += nfq_ct->build_size(ct);
else
ct = NULL;
}
return ct;
}
struct nf_conn *
nfqnl_ct_parse(const struct sk_buff *skb, const struct nlattr *attr,
enum ip_conntrack_info *ctinfo)
{
struct nfq_ct_hook *nfq_ct;
struct nf_conn *ct;
/* rcu_read_lock()ed by __nf_queue already. */
nfq_ct = rcu_dereference(nfq_ct_hook);
if (nfq_ct == NULL)
return NULL;
ct = nf_ct_get(skb, ctinfo);
if (ct && !nf_ct_is_untracked(ct))
nfq_ct->parse(attr, ct);
return ct;
}
int nfqnl_ct_put(struct sk_buff *skb, struct nf_conn *ct,
enum ip_conntrack_info ctinfo)
{
struct nfq_ct_hook *nfq_ct;
struct nlattr *nest_parms;
u_int32_t tmp;
nfq_ct = rcu_dereference(nfq_ct_hook);
if (nfq_ct == NULL)
return 0;
nest_parms = nla_nest_start(skb, NFQA_CT | NLA_F_NESTED);
if (!nest_parms)
goto nla_put_failure;
if (nfq_ct->build(skb, ct) < 0)
goto nla_put_failure;
nla_nest_end(skb, nest_parms);
tmp = ctinfo;
if (nla_put_be32(skb, NFQA_CT_INFO, htonl(tmp)))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
void nfqnl_ct_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,
enum ip_conntrack_info ctinfo, int diff)
{
struct nfq_ct_hook *nfq_ct;
nfq_ct = rcu_dereference(nfq_ct_hook);
if (nfq_ct == NULL)
return;
if ((ct->status & IPS_NAT_MASK) && diff)
nfq_ct->seq_adjust(skb, ct, ctinfo, diff);
}
int nfqnl_attach_expect(struct nf_conn *ct, const struct nlattr *attr,
u32 portid, u32 report)
{
struct nfq_ct_hook *nfq_ct;
if (nf_ct_is_untracked(ct))
return 0;
nfq_ct = rcu_dereference(nfq_ct_hook);
if (nfq_ct == NULL)
return -EOPNOTSUPP;
return nfq_ct->attach_expect(attr, ct, portid, report);
}