2 * Connection state tracking for netfilter. This is separated from,
3 * but required by, the (future) NAT layer; it can also be used by an iptables
6 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
7 * - generalize L3 protocol dependent part.
9 * Derived from include/linux/netfiter_ipv4/ip_conntrack.h
12 #ifndef _NF_CONNTRACK_H
13 #define _NF_CONNTRACK_H
15 #include <linux/netfilter/nf_conntrack_common.h>
17 #include <linux/bitops.h>
18 #include <linux/compiler.h>
19 #include <linux/atomic.h>
20 #include <linux/rhashtable.h>
22 #include <linux/netfilter/nf_conntrack_tcp.h>
23 #include <linux/netfilter/nf_conntrack_dccp.h>
24 #include <linux/netfilter/nf_conntrack_sctp.h>
25 #include <linux/netfilter/nf_conntrack_proto_gre.h>
26 #include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
28 #include <net/netfilter/nf_conntrack_tuple.h>
30 /* per conntrack: protocol private data */
31 union nf_conntrack_proto
{
32 /* insert conntrack proto private data here */
33 struct nf_ct_dccp dccp
;
34 struct ip_ct_sctp sctp
;
37 unsigned int tmpl_padto
;
40 union nf_conntrack_expect_proto
{
41 /* insert expect proto private data here */
44 #include <linux/types.h>
45 #include <linux/skbuff.h>
47 #ifdef CONFIG_NETFILTER_DEBUG
48 #define NF_CT_ASSERT(x) WARN_ON(!(x))
50 #define NF_CT_ASSERT(x)
53 struct nf_conntrack_helper
;
55 /* Must be kept in sync with the classes defined by helpers */
56 #define NF_CT_MAX_EXPECT_CLASSES 4
58 /* nf_conn feature for connections that have a helper */
61 struct nf_conntrack_helper __rcu
*helper
;
63 struct hlist_head expectations
;
65 /* Current number of expected connections */
66 u8 expecting
[NF_CT_MAX_EXPECT_CLASSES
];
68 /* private helper information. */
72 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
73 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
76 /* Usage count in here is 1 for hash table, 1 per skb,
77 * plus 1 for any connection(s) we are `master' for
79 * Hint, SKB address this struct and refcnt via skb->nfct and
80 * helpers nf_conntrack_get() and nf_conntrack_put().
81 * Helper nf_ct_put() equals nf_conntrack_put() by dec refcnt,
82 * beware nf_ct_get() is different and don't inc refcnt.
84 struct nf_conntrack ct_general
;
89 #ifdef CONFIG_NF_CONNTRACK_ZONES
90 struct nf_conntrack_zone zone
;
92 /* XXX should I move this to the tail ? - Y.K */
93 /* These are my tuples; original and reply */
94 struct nf_conntrack_tuple_hash tuplehash
[IP_CT_DIR_MAX
];
96 /* Have we seen traffic both ways yet? (bitset) */
99 /* jiffies32 when this ct is considered dead */
102 possible_net_t ct_net
;
104 #if IS_ENABLED(CONFIG_NF_NAT)
105 struct rhlist_head nat_bysource
;
107 /* all members below initialized via memset */
108 u8 __nfct_init_offset
[0];
110 /* If we were expected by an expectation, this will be it */
111 struct nf_conn
*master
;
113 #if defined(CONFIG_NF_CONNTRACK_MARK)
117 #ifdef CONFIG_NF_CONNTRACK_SECMARK
122 struct nf_ct_ext
*ext
;
124 /* Storage reserved for other modules, must be the last member */
125 union nf_conntrack_proto proto
;
128 static inline struct nf_conn
*
129 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash
*hash
)
131 return container_of(hash
, struct nf_conn
,
132 tuplehash
[hash
->tuple
.dst
.dir
]);
135 static inline u_int16_t
nf_ct_l3num(const struct nf_conn
*ct
)
137 return ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
.src
.l3num
;
140 static inline u_int8_t
nf_ct_protonum(const struct nf_conn
*ct
)
142 return ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
.dst
.protonum
;
145 #define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
147 /* get master conntrack via master expectation */
148 #define master_ct(conntr) (conntr->master)
150 extern struct net init_net
;
152 static inline struct net
*nf_ct_net(const struct nf_conn
*ct
)
154 return read_pnet(&ct
->ct_net
);
157 /* Alter reply tuple (maybe alter helper). */
158 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
159 const struct nf_conntrack_tuple
*newreply
);
161 /* Is this tuple taken? (ignoring any belonging to the given
163 int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
164 const struct nf_conn
*ignored_conntrack
);
166 #define NFCT_INFOMASK 7UL
168 /* Return conntrack_info and tuple hash for given skb. */
169 static inline struct nf_conn
*
170 nf_ct_get(const struct sk_buff
*skb
, enum ip_conntrack_info
*ctinfo
)
172 *ctinfo
= skb
->nfctinfo
;
173 return (struct nf_conn
*)skb
->nfct
;
176 /* decrement reference count on a conntrack */
177 static inline void nf_ct_put(struct nf_conn
*ct
)
180 nf_conntrack_put(&ct
->ct_general
);
183 /* Protocol module loading */
184 int nf_ct_l3proto_try_module_get(unsigned short l3proto
);
185 void nf_ct_l3proto_module_put(unsigned short l3proto
);
187 /* load module; enable/disable conntrack in this namespace */
188 int nf_ct_netns_get(struct net
*net
, u8 nfproto
);
189 void nf_ct_netns_put(struct net
*net
, u8 nfproto
);
192 * Allocate a hashtable of hlist_head (if nulls == 0),
193 * or hlist_nulls_head (if nulls == 1)
195 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
);
197 void nf_ct_free_hashtable(void *hash
, unsigned int size
);
199 int nf_conntrack_hash_check_insert(struct nf_conn
*ct
);
200 bool nf_ct_delete(struct nf_conn
*ct
, u32 pid
, int report
);
202 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
203 u_int16_t l3num
, struct net
*net
,
204 struct nf_conntrack_tuple
*tuple
);
205 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
206 const struct nf_conntrack_tuple
*orig
);
208 void __nf_ct_refresh_acct(struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
,
209 const struct sk_buff
*skb
,
210 unsigned long extra_jiffies
, int do_acct
);
212 /* Refresh conntrack for this many jiffies and do accounting */
213 static inline void nf_ct_refresh_acct(struct nf_conn
*ct
,
214 enum ip_conntrack_info ctinfo
,
215 const struct sk_buff
*skb
,
216 unsigned long extra_jiffies
)
218 __nf_ct_refresh_acct(ct
, ctinfo
, skb
, extra_jiffies
, 1);
221 /* Refresh conntrack for this many jiffies */
222 static inline void nf_ct_refresh(struct nf_conn
*ct
,
223 const struct sk_buff
*skb
,
224 unsigned long extra_jiffies
)
226 __nf_ct_refresh_acct(ct
, 0, skb
, extra_jiffies
, 0);
229 /* kill conntrack and do accounting */
230 bool nf_ct_kill_acct(struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
,
231 const struct sk_buff
*skb
);
233 /* kill conntrack without accounting */
234 static inline bool nf_ct_kill(struct nf_conn
*ct
)
236 return nf_ct_delete(ct
, 0, 0);
239 /* These are for NAT. Icky. */
240 extern s32 (*nf_ct_nat_offset
)(const struct nf_conn
*ct
,
241 enum ip_conntrack_dir dir
,
244 /* Fake conntrack entry for untracked connections */
245 DECLARE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
246 static inline struct nf_conn
*nf_ct_untracked_get(void)
248 return raw_cpu_ptr(&nf_conntrack_untracked
);
250 void nf_ct_untracked_status_or(unsigned long bits
);
252 /* Iterate over all conntracks: if iter returns true, it's deleted. */
253 void nf_ct_iterate_cleanup(struct net
*net
,
254 int (*iter
)(struct nf_conn
*i
, void *data
),
255 void *data
, u32 portid
, int report
);
257 struct nf_conntrack_zone
;
259 void nf_conntrack_free(struct nf_conn
*ct
);
260 struct nf_conn
*nf_conntrack_alloc(struct net
*net
,
261 const struct nf_conntrack_zone
*zone
,
262 const struct nf_conntrack_tuple
*orig
,
263 const struct nf_conntrack_tuple
*repl
,
266 static inline int nf_ct_is_template(const struct nf_conn
*ct
)
268 return test_bit(IPS_TEMPLATE_BIT
, &ct
->status
);
271 /* It's confirmed if it is, or has been in the hash table. */
272 static inline int nf_ct_is_confirmed(const struct nf_conn
*ct
)
274 return test_bit(IPS_CONFIRMED_BIT
, &ct
->status
);
277 static inline int nf_ct_is_dying(const struct nf_conn
*ct
)
279 return test_bit(IPS_DYING_BIT
, &ct
->status
);
282 static inline int nf_ct_is_untracked(const struct nf_conn
*ct
)
284 return test_bit(IPS_UNTRACKED_BIT
, &ct
->status
);
287 /* Packet is received from loopback */
288 static inline bool nf_is_loopback_packet(const struct sk_buff
*skb
)
290 return skb
->dev
&& skb
->skb_iif
&& skb
->dev
->flags
& IFF_LOOPBACK
;
293 #define nfct_time_stamp ((u32)(jiffies))
295 /* jiffies until ct expires, 0 if already expired */
296 static inline unsigned long nf_ct_expires(const struct nf_conn
*ct
)
298 s32 timeout
= ct
->timeout
- nfct_time_stamp
;
300 return timeout
> 0 ? timeout
: 0;
303 static inline bool nf_ct_is_expired(const struct nf_conn
*ct
)
305 return (__s32
)(ct
->timeout
- nfct_time_stamp
) <= 0;
308 /* use after obtaining a reference count */
309 static inline bool nf_ct_should_gc(const struct nf_conn
*ct
)
311 return nf_ct_is_expired(ct
) && nf_ct_is_confirmed(ct
) &&
317 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
);
318 int nf_conntrack_hash_resize(unsigned int hashsize
);
320 extern struct hlist_nulls_head
*nf_conntrack_hash
;
321 extern unsigned int nf_conntrack_htable_size
;
322 extern seqcount_t nf_conntrack_generation
;
323 extern unsigned int nf_conntrack_max
;
325 /* must be called with rcu read lock held */
327 nf_conntrack_get_ht(struct hlist_nulls_head
**hash
, unsigned int *hsize
)
329 struct hlist_nulls_head
*hptr
;
330 unsigned int sequence
, hsz
;
333 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
334 hsz
= nf_conntrack_htable_size
;
335 hptr
= nf_conntrack_hash
;
336 } while (read_seqcount_retry(&nf_conntrack_generation
, sequence
));
342 struct nf_conn
*nf_ct_tmpl_alloc(struct net
*net
,
343 const struct nf_conntrack_zone
*zone
,
345 void nf_ct_tmpl_free(struct nf_conn
*tmpl
);
348 nf_ct_set(struct sk_buff
*skb
, struct nf_conn
*ct
, enum ip_conntrack_info info
)
350 skb
->nfct
= &ct
->ct_general
;
351 skb
->nfctinfo
= info
;
354 #define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count)
355 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
356 #define NF_CT_STAT_ADD_ATOMIC(net, count, v) this_cpu_add((net)->ct.stat->count, (v))
358 #define MODULE_ALIAS_NFCT_HELPER(helper) \
359 MODULE_ALIAS("nfct-helper-" helper)
361 #endif /* _NF_CONNTRACK_H */