1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Connection state tracking for netfilter. This is separated from,
4 * but required by, the (future) NAT layer; it can also be used by an iptables
7 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
8 * - generalize L3 protocol dependent part.
10 * Derived from include/linux/netfiter_ipv4/ip_conntrack.h
13 #ifndef _NF_CONNTRACK_H
14 #define _NF_CONNTRACK_H
16 #include <linux/netfilter/nf_conntrack_common.h>
18 #include <linux/bitops.h>
19 #include <linux/compiler.h>
20 #include <linux/atomic.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 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
48 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
51 /* Usage count in here is 1 for hash table, 1 per skb,
52 * plus 1 for any connection(s) we are `master' for
54 * Hint, SKB address this struct and refcnt via skb->_nfct and
55 * helpers nf_conntrack_get() and nf_conntrack_put().
56 * Helper nf_ct_put() equals nf_conntrack_put() by dec refcnt,
57 * beware nf_ct_get() is different and don't inc refcnt.
59 struct nf_conntrack ct_general
;
64 #ifdef CONFIG_NF_CONNTRACK_ZONES
65 struct nf_conntrack_zone zone
;
67 /* XXX should I move this to the tail ? - Y.K */
68 /* These are my tuples; original and reply */
69 struct nf_conntrack_tuple_hash tuplehash
[IP_CT_DIR_MAX
];
71 /* Have we seen traffic both ways yet? (bitset) */
74 /* jiffies32 when this ct is considered dead */
77 possible_net_t ct_net
;
79 #if IS_ENABLED(CONFIG_NF_NAT)
80 struct hlist_node nat_bysource
;
82 /* all members below initialized via memset */
83 u8 __nfct_init_offset
[0];
85 /* If we were expected by an expectation, this will be it */
86 struct nf_conn
*master
;
88 #if defined(CONFIG_NF_CONNTRACK_MARK)
92 #ifdef CONFIG_NF_CONNTRACK_SECMARK
97 struct nf_ct_ext
*ext
;
99 /* Storage reserved for other modules, must be the last member */
100 union nf_conntrack_proto proto
;
103 static inline struct nf_conn
*
104 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash
*hash
)
106 return container_of(hash
, struct nf_conn
,
107 tuplehash
[hash
->tuple
.dst
.dir
]);
110 static inline u_int16_t
nf_ct_l3num(const struct nf_conn
*ct
)
112 return ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
.src
.l3num
;
115 static inline u_int8_t
nf_ct_protonum(const struct nf_conn
*ct
)
117 return ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
.dst
.protonum
;
120 #define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
122 /* get master conntrack via master expectation */
123 #define master_ct(conntr) (conntr->master)
125 extern struct net init_net
;
127 static inline struct net
*nf_ct_net(const struct nf_conn
*ct
)
129 return read_pnet(&ct
->ct_net
);
132 /* Alter reply tuple (maybe alter helper). */
133 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
134 const struct nf_conntrack_tuple
*newreply
);
136 /* Is this tuple taken? (ignoring any belonging to the given
138 int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
139 const struct nf_conn
*ignored_conntrack
);
141 #define NFCT_INFOMASK 7UL
142 #define NFCT_PTRMASK ~(NFCT_INFOMASK)
144 /* Return conntrack_info and tuple hash for given skb. */
145 static inline struct nf_conn
*
146 nf_ct_get(const struct sk_buff
*skb
, enum ip_conntrack_info
*ctinfo
)
148 *ctinfo
= skb
->_nfct
& NFCT_INFOMASK
;
150 return (struct nf_conn
*)(skb
->_nfct
& NFCT_PTRMASK
);
153 /* decrement reference count on a conntrack */
154 static inline void nf_ct_put(struct nf_conn
*ct
)
157 nf_conntrack_put(&ct
->ct_general
);
160 /* Protocol module loading */
161 int nf_ct_l3proto_try_module_get(unsigned short l3proto
);
162 void nf_ct_l3proto_module_put(unsigned short l3proto
);
164 /* load module; enable/disable conntrack in this namespace */
165 int nf_ct_netns_get(struct net
*net
, u8 nfproto
);
166 void nf_ct_netns_put(struct net
*net
, u8 nfproto
);
169 * Allocate a hashtable of hlist_head (if nulls == 0),
170 * or hlist_nulls_head (if nulls == 1)
172 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
);
174 void nf_ct_free_hashtable(void *hash
, unsigned int size
);
176 int nf_conntrack_hash_check_insert(struct nf_conn
*ct
);
177 bool nf_ct_delete(struct nf_conn
*ct
, u32 pid
, int report
);
179 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
180 u_int16_t l3num
, struct net
*net
,
181 struct nf_conntrack_tuple
*tuple
);
182 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
183 const struct nf_conntrack_tuple
*orig
);
185 void __nf_ct_refresh_acct(struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
,
186 const struct sk_buff
*skb
,
187 unsigned long extra_jiffies
, int do_acct
);
189 /* Refresh conntrack for this many jiffies and do accounting */
190 static inline void nf_ct_refresh_acct(struct nf_conn
*ct
,
191 enum ip_conntrack_info ctinfo
,
192 const struct sk_buff
*skb
,
193 unsigned long extra_jiffies
)
195 __nf_ct_refresh_acct(ct
, ctinfo
, skb
, extra_jiffies
, 1);
198 /* Refresh conntrack for this many jiffies */
199 static inline void nf_ct_refresh(struct nf_conn
*ct
,
200 const struct sk_buff
*skb
,
201 unsigned long extra_jiffies
)
203 __nf_ct_refresh_acct(ct
, 0, skb
, extra_jiffies
, 0);
206 /* kill conntrack and do accounting */
207 bool nf_ct_kill_acct(struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
,
208 const struct sk_buff
*skb
);
210 /* kill conntrack without accounting */
211 static inline bool nf_ct_kill(struct nf_conn
*ct
)
213 return nf_ct_delete(ct
, 0, 0);
216 /* These are for NAT. Icky. */
217 extern s32 (*nf_ct_nat_offset
)(const struct nf_conn
*ct
,
218 enum ip_conntrack_dir dir
,
221 /* Set all unconfirmed conntrack as dying */
222 void nf_ct_unconfirmed_destroy(struct net
*);
224 /* Iterate over all conntracks: if iter returns true, it's deleted. */
225 void nf_ct_iterate_cleanup_net(struct net
*net
,
226 int (*iter
)(struct nf_conn
*i
, void *data
),
227 void *data
, u32 portid
, int report
);
229 /* also set unconfirmed conntracks as dying. Only use in module exit path. */
230 void nf_ct_iterate_destroy(int (*iter
)(struct nf_conn
*i
, void *data
),
233 struct nf_conntrack_zone
;
235 void nf_conntrack_free(struct nf_conn
*ct
);
236 struct nf_conn
*nf_conntrack_alloc(struct net
*net
,
237 const struct nf_conntrack_zone
*zone
,
238 const struct nf_conntrack_tuple
*orig
,
239 const struct nf_conntrack_tuple
*repl
,
242 static inline int nf_ct_is_template(const struct nf_conn
*ct
)
244 return test_bit(IPS_TEMPLATE_BIT
, &ct
->status
);
247 /* It's confirmed if it is, or has been in the hash table. */
248 static inline int nf_ct_is_confirmed(const struct nf_conn
*ct
)
250 return test_bit(IPS_CONFIRMED_BIT
, &ct
->status
);
253 static inline int nf_ct_is_dying(const struct nf_conn
*ct
)
255 return test_bit(IPS_DYING_BIT
, &ct
->status
);
258 /* Packet is received from loopback */
259 static inline bool nf_is_loopback_packet(const struct sk_buff
*skb
)
261 return skb
->dev
&& skb
->skb_iif
&& skb
->dev
->flags
& IFF_LOOPBACK
;
264 #define nfct_time_stamp ((u32)(jiffies))
266 /* jiffies until ct expires, 0 if already expired */
267 static inline unsigned long nf_ct_expires(const struct nf_conn
*ct
)
269 s32 timeout
= ct
->timeout
- nfct_time_stamp
;
271 return timeout
> 0 ? timeout
: 0;
274 static inline bool nf_ct_is_expired(const struct nf_conn
*ct
)
276 return (__s32
)(ct
->timeout
- nfct_time_stamp
) <= 0;
279 /* use after obtaining a reference count */
280 static inline bool nf_ct_should_gc(const struct nf_conn
*ct
)
282 return nf_ct_is_expired(ct
) && nf_ct_is_confirmed(ct
) &&
288 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
);
289 int nf_conntrack_hash_resize(unsigned int hashsize
);
291 extern struct hlist_nulls_head
*nf_conntrack_hash
;
292 extern unsigned int nf_conntrack_htable_size
;
293 extern seqcount_t nf_conntrack_generation
;
294 extern unsigned int nf_conntrack_max
;
296 /* must be called with rcu read lock held */
298 nf_conntrack_get_ht(struct hlist_nulls_head
**hash
, unsigned int *hsize
)
300 struct hlist_nulls_head
*hptr
;
301 unsigned int sequence
, hsz
;
304 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
305 hsz
= nf_conntrack_htable_size
;
306 hptr
= nf_conntrack_hash
;
307 } while (read_seqcount_retry(&nf_conntrack_generation
, sequence
));
313 struct nf_conn
*nf_ct_tmpl_alloc(struct net
*net
,
314 const struct nf_conntrack_zone
*zone
,
316 void nf_ct_tmpl_free(struct nf_conn
*tmpl
);
319 nf_ct_set(struct sk_buff
*skb
, struct nf_conn
*ct
, enum ip_conntrack_info info
)
321 skb
->_nfct
= (unsigned long)ct
| info
;
324 #define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count)
325 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
326 #define NF_CT_STAT_ADD_ATOMIC(net, count, v) this_cpu_add((net)->ct.stat->count, (v))
328 #define MODULE_ALIAS_NFCT_HELPER(helper) \
329 MODULE_ALIAS("nfct-helper-" helper)
331 #endif /* _NF_CONNTRACK_H */