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
;
39 union nf_conntrack_expect_proto
{
40 /* insert expect proto private data here */
43 #include <linux/types.h>
44 #include <linux/skbuff.h>
45 #include <linux/timer.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/destruct timer, 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 /* Timer function; drops refcnt when it goes off. */
100 struct timer_list timeout
;
102 possible_net_t ct_net
;
104 /* all members below initialized via memset */
105 u8 __nfct_init_offset
[0];
107 /* If we were expected by an expectation, this will be it */
108 struct nf_conn
*master
;
110 #if defined(CONFIG_NF_CONNTRACK_MARK)
114 #ifdef CONFIG_NF_CONNTRACK_SECMARK
119 struct nf_ct_ext
*ext
;
121 #if IS_ENABLED(CONFIG_NF_NAT)
122 struct rhash_head nat_bysource
;
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 /* Return conntrack_info and tuple hash for given skb. */
167 static inline struct nf_conn
*
168 nf_ct_get(const struct sk_buff
*skb
, enum ip_conntrack_info
*ctinfo
)
170 *ctinfo
= skb
->nfctinfo
;
171 return (struct nf_conn
*)skb
->nfct
;
174 /* decrement reference count on a conntrack */
175 static inline void nf_ct_put(struct nf_conn
*ct
)
178 nf_conntrack_put(&ct
->ct_general
);
181 /* Protocol module loading */
182 int nf_ct_l3proto_try_module_get(unsigned short l3proto
);
183 void nf_ct_l3proto_module_put(unsigned short l3proto
);
186 * Allocate a hashtable of hlist_head (if nulls == 0),
187 * or hlist_nulls_head (if nulls == 1)
189 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
);
191 void nf_ct_free_hashtable(void *hash
, unsigned int size
);
193 int nf_conntrack_hash_check_insert(struct nf_conn
*ct
);
194 bool nf_ct_delete(struct nf_conn
*ct
, u32 pid
, int report
);
196 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
197 u_int16_t l3num
, struct net
*net
,
198 struct nf_conntrack_tuple
*tuple
);
199 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
200 const struct nf_conntrack_tuple
*orig
);
202 void __nf_ct_refresh_acct(struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
,
203 const struct sk_buff
*skb
,
204 unsigned long extra_jiffies
, int do_acct
);
206 /* Refresh conntrack for this many jiffies and do accounting */
207 static inline void nf_ct_refresh_acct(struct nf_conn
*ct
,
208 enum ip_conntrack_info ctinfo
,
209 const struct sk_buff
*skb
,
210 unsigned long extra_jiffies
)
212 __nf_ct_refresh_acct(ct
, ctinfo
, skb
, extra_jiffies
, 1);
215 /* Refresh conntrack for this many jiffies */
216 static inline void nf_ct_refresh(struct nf_conn
*ct
,
217 const struct sk_buff
*skb
,
218 unsigned long extra_jiffies
)
220 __nf_ct_refresh_acct(ct
, 0, skb
, extra_jiffies
, 0);
223 bool __nf_ct_kill_acct(struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
,
224 const struct sk_buff
*skb
, int do_acct
);
226 /* kill conntrack and do accounting */
227 static inline bool nf_ct_kill_acct(struct nf_conn
*ct
,
228 enum ip_conntrack_info ctinfo
,
229 const struct sk_buff
*skb
)
231 return __nf_ct_kill_acct(ct
, ctinfo
, skb
, 1);
234 /* kill conntrack without accounting */
235 static inline bool nf_ct_kill(struct nf_conn
*ct
)
237 return __nf_ct_kill_acct(ct
, 0, NULL
, 0);
240 /* These are for NAT. Icky. */
241 extern s32 (*nf_ct_nat_offset
)(const struct nf_conn
*ct
,
242 enum ip_conntrack_dir dir
,
245 /* Fake conntrack entry for untracked connections */
246 DECLARE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
247 static inline struct nf_conn
*nf_ct_untracked_get(void)
249 return raw_cpu_ptr(&nf_conntrack_untracked
);
251 void nf_ct_untracked_status_or(unsigned long bits
);
253 /* Iterate over all conntracks: if iter returns true, it's deleted. */
254 void nf_ct_iterate_cleanup(struct net
*net
,
255 int (*iter
)(struct nf_conn
*i
, void *data
),
256 void *data
, u32 portid
, int report
);
258 struct nf_conntrack_zone
;
260 void nf_conntrack_free(struct nf_conn
*ct
);
261 struct nf_conn
*nf_conntrack_alloc(struct net
*net
,
262 const struct nf_conntrack_zone
*zone
,
263 const struct nf_conntrack_tuple
*orig
,
264 const struct nf_conntrack_tuple
*repl
,
267 static inline int nf_ct_is_template(const struct nf_conn
*ct
)
269 return test_bit(IPS_TEMPLATE_BIT
, &ct
->status
);
272 /* It's confirmed if it is, or has been in the hash table. */
273 static inline int nf_ct_is_confirmed(const struct nf_conn
*ct
)
275 return test_bit(IPS_CONFIRMED_BIT
, &ct
->status
);
278 static inline int nf_ct_is_dying(const struct nf_conn
*ct
)
280 return test_bit(IPS_DYING_BIT
, &ct
->status
);
283 static inline int nf_ct_is_untracked(const struct nf_conn
*ct
)
285 return test_bit(IPS_UNTRACKED_BIT
, &ct
->status
);
288 /* Packet is received from loopback */
289 static inline bool nf_is_loopback_packet(const struct sk_buff
*skb
)
291 return skb
->dev
&& skb
->skb_iif
&& skb
->dev
->flags
& IFF_LOOPBACK
;
294 /* jiffies until ct expires, 0 if already expired */
295 static inline unsigned long nf_ct_expires(const struct nf_conn
*ct
)
297 long timeout
= (long)ct
->timeout
.expires
- (long)jiffies
;
299 return timeout
> 0 ? timeout
: 0;
304 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
);
305 int nf_conntrack_hash_resize(unsigned int hashsize
);
306 extern unsigned int nf_conntrack_htable_size
;
307 extern unsigned int nf_conntrack_max
;
309 struct nf_conn
*nf_ct_tmpl_alloc(struct net
*net
,
310 const struct nf_conntrack_zone
*zone
,
312 void nf_ct_tmpl_free(struct nf_conn
*tmpl
);
314 #define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count)
315 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
316 #define NF_CT_STAT_ADD_ATOMIC(net, count, v) this_cpu_add((net)->ct.stat->count, (v))
318 #define MODULE_ALIAS_NFCT_HELPER(helper) \
319 MODULE_ALIAS("nfct-helper-" helper)
321 #endif /* _NF_CONNTRACK_H */