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>
21 #include <linux/netfilter/nf_conntrack_tcp.h>
22 #include <linux/netfilter/nf_conntrack_dccp.h>
23 #include <linux/netfilter/nf_conntrack_sctp.h>
24 #include <linux/netfilter/nf_conntrack_proto_gre.h>
25 #include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
27 #include <net/netfilter/nf_conntrack_tuple.h>
29 /* per conntrack: protocol private data */
30 union nf_conntrack_proto {
31 /* insert conntrack proto private data here */
32 struct nf_ct_dccp dccp;
33 struct ip_ct_sctp sctp;
38 union nf_conntrack_expect_proto {
39 /* insert expect proto private data here */
42 #include <linux/types.h>
43 #include <linux/skbuff.h>
45 #ifdef CONFIG_NETFILTER_DEBUG
46 #define NF_CT_ASSERT(x) WARN_ON(!(x))
48 #define NF_CT_ASSERT(x)
51 struct nf_conntrack_helper;
53 /* Must be kept in sync with the classes defined by helpers */
54 #define NF_CT_MAX_EXPECT_CLASSES 4
56 /* nf_conn feature for connections that have a helper */
59 struct nf_conntrack_helper __rcu *helper;
61 struct hlist_head expectations;
63 /* Current number of expected connections */
64 u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
66 /* private helper information. */
70 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
71 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
74 /* Usage count in here is 1 for hash table, 1 per skb,
75 * plus 1 for any connection(s) we are `master' for
77 * Hint, SKB address this struct and refcnt via skb->nfct and
78 * helpers nf_conntrack_get() and nf_conntrack_put().
79 * Helper nf_ct_put() equals nf_conntrack_put() by dec refcnt,
80 * beware nf_ct_get() is different and don't inc refcnt.
82 struct nf_conntrack ct_general;
87 #ifdef CONFIG_NF_CONNTRACK_ZONES
88 struct nf_conntrack_zone zone;
90 /* XXX should I move this to the tail ? - Y.K */
91 /* These are my tuples; original and reply */
92 struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
94 /* Have we seen traffic both ways yet? (bitset) */
97 /* jiffies32 when this ct is considered dead */
100 possible_net_t ct_net;
102 #if IS_ENABLED(CONFIG_NF_NAT)
103 struct hlist_node nat_bysource;
105 /* all members below initialized via memset */
106 struct { } __nfct_init_offset;
108 /* If we were expected by an expectation, this will be it */
109 struct nf_conn *master;
111 #if defined(CONFIG_NF_CONNTRACK_MARK)
115 #ifdef CONFIG_NF_CONNTRACK_SECMARK
120 struct nf_ct_ext *ext;
122 /* Storage reserved for other modules, must be the last member */
123 union nf_conntrack_proto proto;
126 static inline struct nf_conn *
127 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
129 return container_of(hash, struct nf_conn,
130 tuplehash[hash->tuple.dst.dir]);
133 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
135 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
138 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
140 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
143 #define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
145 /* get master conntrack via master expectation */
146 #define master_ct(conntr) (conntr->master)
148 extern struct net init_net;
150 static inline struct net *nf_ct_net(const struct nf_conn *ct)
152 return read_pnet(&ct->ct_net);
155 /* Alter reply tuple (maybe alter helper). */
156 void nf_conntrack_alter_reply(struct nf_conn *ct,
157 const struct nf_conntrack_tuple *newreply);
159 /* Is this tuple taken? (ignoring any belonging to the given
161 int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
162 const struct nf_conn *ignored_conntrack);
164 /* Return conntrack_info and tuple hash for given skb. */
165 static inline struct nf_conn *
166 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
168 *ctinfo = skb->nfctinfo;
169 return (struct nf_conn *)skb->nfct;
172 /* decrement reference count on a conntrack */
173 static inline void nf_ct_put(struct nf_conn *ct)
176 nf_conntrack_put(&ct->ct_general);
179 /* Protocol module loading */
180 int nf_ct_l3proto_try_module_get(unsigned short l3proto);
181 void nf_ct_l3proto_module_put(unsigned short l3proto);
184 * Allocate a hashtable of hlist_head (if nulls == 0),
185 * or hlist_nulls_head (if nulls == 1)
187 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
189 void nf_ct_free_hashtable(void *hash, unsigned int size);
191 int nf_conntrack_hash_check_insert(struct nf_conn *ct);
192 bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report);
194 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
195 u_int16_t l3num, struct net *net,
196 struct nf_conntrack_tuple *tuple);
197 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
198 const struct nf_conntrack_tuple *orig);
200 void __nf_ct_refresh_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
201 const struct sk_buff *skb,
202 unsigned long extra_jiffies, int do_acct);
204 /* Refresh conntrack for this many jiffies and do accounting */
205 static inline void nf_ct_refresh_acct(struct nf_conn *ct,
206 enum ip_conntrack_info ctinfo,
207 const struct sk_buff *skb,
208 unsigned long extra_jiffies)
210 __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
213 /* Refresh conntrack for this many jiffies */
214 static inline void nf_ct_refresh(struct nf_conn *ct,
215 const struct sk_buff *skb,
216 unsigned long extra_jiffies)
218 __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
221 /* kill conntrack and do accounting */
222 bool nf_ct_kill_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
223 const struct sk_buff *skb);
225 /* kill conntrack without accounting */
226 static inline bool nf_ct_kill(struct nf_conn *ct)
228 return nf_ct_delete(ct, 0, 0);
231 /* These are for NAT. Icky. */
232 extern s32 (*nf_ct_nat_offset)(const struct nf_conn *ct,
233 enum ip_conntrack_dir dir,
236 /* Fake conntrack entry for untracked connections */
237 DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
238 static inline struct nf_conn *nf_ct_untracked_get(void)
240 return raw_cpu_ptr(&nf_conntrack_untracked);
242 void nf_ct_untracked_status_or(unsigned long bits);
244 /* Iterate over all conntracks: if iter returns true, it's deleted. */
245 void nf_ct_iterate_cleanup(struct net *net,
246 int (*iter)(struct nf_conn *i, void *data),
247 void *data, u32 portid, int report);
249 struct nf_conntrack_zone;
251 void nf_conntrack_free(struct nf_conn *ct);
252 struct nf_conn *nf_conntrack_alloc(struct net *net,
253 const struct nf_conntrack_zone *zone,
254 const struct nf_conntrack_tuple *orig,
255 const struct nf_conntrack_tuple *repl,
258 static inline int nf_ct_is_template(const struct nf_conn *ct)
260 return test_bit(IPS_TEMPLATE_BIT, &ct->status);
263 /* It's confirmed if it is, or has been in the hash table. */
264 static inline int nf_ct_is_confirmed(const struct nf_conn *ct)
266 return test_bit(IPS_CONFIRMED_BIT, &ct->status);
269 static inline int nf_ct_is_dying(const struct nf_conn *ct)
271 return test_bit(IPS_DYING_BIT, &ct->status);
274 static inline int nf_ct_is_untracked(const struct nf_conn *ct)
276 return test_bit(IPS_UNTRACKED_BIT, &ct->status);
279 /* Packet is received from loopback */
280 static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
282 return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
285 #define nfct_time_stamp ((u32)(jiffies))
287 /* jiffies until ct expires, 0 if already expired */
288 static inline unsigned long nf_ct_expires(const struct nf_conn *ct)
290 s32 timeout = ct->timeout - nfct_time_stamp;
292 return timeout > 0 ? timeout : 0;
295 static inline bool nf_ct_is_expired(const struct nf_conn *ct)
297 return (__s32)(ct->timeout - nfct_time_stamp) <= 0;
300 /* use after obtaining a reference count */
301 static inline bool nf_ct_should_gc(const struct nf_conn *ct)
303 return nf_ct_is_expired(ct) && nf_ct_is_confirmed(ct) &&
309 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
310 int nf_conntrack_hash_resize(unsigned int hashsize);
312 extern struct hlist_nulls_head *nf_conntrack_hash;
313 extern unsigned int nf_conntrack_htable_size;
314 extern seqcount_t nf_conntrack_generation;
315 extern unsigned int nf_conntrack_max;
317 /* must be called with rcu read lock held */
319 nf_conntrack_get_ht(struct hlist_nulls_head **hash, unsigned int *hsize)
321 struct hlist_nulls_head *hptr;
322 unsigned int sequence, hsz;
325 sequence = read_seqcount_begin(&nf_conntrack_generation);
326 hsz = nf_conntrack_htable_size;
327 hptr = nf_conntrack_hash;
328 } while (read_seqcount_retry(&nf_conntrack_generation, sequence));
334 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
335 const struct nf_conntrack_zone *zone,
337 void nf_ct_tmpl_free(struct nf_conn *tmpl);
339 u32 nf_ct_get_id(const struct nf_conn *ct);
341 #define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count)
342 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
343 #define NF_CT_STAT_ADD_ATOMIC(net, count, v) this_cpu_add((net)->ct.stat->count, (v))
345 #define MODULE_ALIAS_NFCT_HELPER(helper) \
346 MODULE_ALIAS("nfct-helper-" helper)
348 #endif /* _NF_CONNTRACK_H */