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>
46 #ifdef CONFIG_NETFILTER_DEBUG
47 #define NF_CT_ASSERT(x) WARN_ON(!(x))
49 #define NF_CT_ASSERT(x)
52 struct nf_conntrack_helper;
54 /* Must be kept in sync with the classes defined by helpers */
55 #define NF_CT_MAX_EXPECT_CLASSES 4
57 /* nf_conn feature for connections that have a helper */
60 struct nf_conntrack_helper __rcu *helper;
62 struct hlist_head expectations;
64 /* Current number of expected connections */
65 u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
67 /* private helper information. */
71 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
72 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
75 /* Usage count in here is 1 for hash table, 1 per skb,
76 * plus 1 for any connection(s) we are `master' for
78 * Hint, SKB address this struct and refcnt via skb->nfct and
79 * helpers nf_conntrack_get() and nf_conntrack_put().
80 * Helper nf_ct_put() equals nf_conntrack_put() by dec refcnt,
81 * beware nf_ct_get() is different and don't inc refcnt.
83 struct nf_conntrack ct_general;
88 #ifdef CONFIG_NF_CONNTRACK_ZONES
89 struct nf_conntrack_zone zone;
91 /* XXX should I move this to the tail ? - Y.K */
92 /* These are my tuples; original and reply */
93 struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
95 /* Have we seen traffic both ways yet? (bitset) */
98 /* jiffies32 when this ct is considered dead */
101 possible_net_t ct_net;
103 #if IS_ENABLED(CONFIG_NF_NAT)
104 struct rhlist_head nat_bysource;
106 /* all members below initialized via memset */
107 u8 __nfct_init_offset[0];
109 /* If we were expected by an expectation, this will be it */
110 struct nf_conn *master;
112 #if defined(CONFIG_NF_CONNTRACK_MARK)
116 #ifdef CONFIG_NF_CONNTRACK_SECMARK
121 struct nf_ct_ext *ext;
123 /* Storage reserved for other modules, must be the last member */
124 union nf_conntrack_proto proto;
127 static inline struct nf_conn *
128 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
130 return container_of(hash, struct nf_conn,
131 tuplehash[hash->tuple.dst.dir]);
134 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
136 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
139 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
141 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
144 #define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
146 /* get master conntrack via master expectation */
147 #define master_ct(conntr) (conntr->master)
149 extern struct net init_net;
151 static inline struct net *nf_ct_net(const struct nf_conn *ct)
153 return read_pnet(&ct->ct_net);
156 /* Alter reply tuple (maybe alter helper). */
157 void nf_conntrack_alter_reply(struct nf_conn *ct,
158 const struct nf_conntrack_tuple *newreply);
160 /* Is this tuple taken? (ignoring any belonging to the given
162 int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
163 const struct nf_conn *ignored_conntrack);
165 /* Return conntrack_info and tuple hash for given skb. */
166 static inline struct nf_conn *
167 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
169 *ctinfo = skb->nfctinfo;
170 return (struct nf_conn *)skb->nfct;
173 /* decrement reference count on a conntrack */
174 static inline void nf_ct_put(struct nf_conn *ct)
177 nf_conntrack_put(&ct->ct_general);
180 /* Protocol module loading */
181 int nf_ct_l3proto_try_module_get(unsigned short l3proto);
182 void nf_ct_l3proto_module_put(unsigned short l3proto);
185 * Allocate a hashtable of hlist_head (if nulls == 0),
186 * or hlist_nulls_head (if nulls == 1)
188 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
190 void nf_ct_free_hashtable(void *hash, unsigned int size);
192 int nf_conntrack_hash_check_insert(struct nf_conn *ct);
193 bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report);
195 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
196 u_int16_t l3num, struct net *net,
197 struct nf_conntrack_tuple *tuple);
198 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
199 const struct nf_conntrack_tuple *orig);
201 void __nf_ct_refresh_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
202 const struct sk_buff *skb,
203 unsigned long extra_jiffies, int do_acct);
205 /* Refresh conntrack for this many jiffies and do accounting */
206 static inline void nf_ct_refresh_acct(struct nf_conn *ct,
207 enum ip_conntrack_info ctinfo,
208 const struct sk_buff *skb,
209 unsigned long extra_jiffies)
211 __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
214 /* Refresh conntrack for this many jiffies */
215 static inline void nf_ct_refresh(struct nf_conn *ct,
216 const struct sk_buff *skb,
217 unsigned long extra_jiffies)
219 __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
222 /* kill conntrack and do accounting */
223 bool nf_ct_kill_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
224 const struct sk_buff *skb);
226 /* kill conntrack without accounting */
227 static inline bool nf_ct_kill(struct nf_conn *ct)
229 return nf_ct_delete(ct, 0, 0);
232 /* These are for NAT. Icky. */
233 extern s32 (*nf_ct_nat_offset)(const struct nf_conn *ct,
234 enum ip_conntrack_dir dir,
237 /* Fake conntrack entry for untracked connections */
238 DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
239 static inline struct nf_conn *nf_ct_untracked_get(void)
241 return raw_cpu_ptr(&nf_conntrack_untracked);
243 void nf_ct_untracked_status_or(unsigned long bits);
245 /* Iterate over all conntracks: if iter returns true, it's deleted. */
246 void nf_ct_iterate_cleanup(struct net *net,
247 int (*iter)(struct nf_conn *i, void *data),
248 void *data, u32 portid, int report);
250 struct nf_conntrack_zone;
252 void nf_conntrack_free(struct nf_conn *ct);
253 struct nf_conn *nf_conntrack_alloc(struct net *net,
254 const struct nf_conntrack_zone *zone,
255 const struct nf_conntrack_tuple *orig,
256 const struct nf_conntrack_tuple *repl,
259 static inline int nf_ct_is_template(const struct nf_conn *ct)
261 return test_bit(IPS_TEMPLATE_BIT, &ct->status);
264 /* It's confirmed if it is, or has been in the hash table. */
265 static inline int nf_ct_is_confirmed(const struct nf_conn *ct)
267 return test_bit(IPS_CONFIRMED_BIT, &ct->status);
270 static inline int nf_ct_is_dying(const struct nf_conn *ct)
272 return test_bit(IPS_DYING_BIT, &ct->status);
275 static inline int nf_ct_is_untracked(const struct nf_conn *ct)
277 return test_bit(IPS_UNTRACKED_BIT, &ct->status);
280 /* Packet is received from loopback */
281 static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
283 return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
286 #define nfct_time_stamp ((u32)(jiffies))
288 /* jiffies until ct expires, 0 if already expired */
289 static inline unsigned long nf_ct_expires(const struct nf_conn *ct)
291 s32 timeout = ct->timeout - nfct_time_stamp;
293 return timeout > 0 ? timeout : 0;
296 static inline bool nf_ct_is_expired(const struct nf_conn *ct)
298 return (__s32)(ct->timeout - nfct_time_stamp) <= 0;
301 /* use after obtaining a reference count */
302 static inline bool nf_ct_should_gc(const struct nf_conn *ct)
304 return nf_ct_is_expired(ct) && nf_ct_is_confirmed(ct) &&
310 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
311 int nf_conntrack_hash_resize(unsigned int hashsize);
313 extern struct hlist_nulls_head *nf_conntrack_hash;
314 extern unsigned int nf_conntrack_htable_size;
315 extern seqcount_t nf_conntrack_generation;
316 extern unsigned int nf_conntrack_max;
318 /* must be called with rcu read lock held */
320 nf_conntrack_get_ht(struct hlist_nulls_head **hash, unsigned int *hsize)
322 struct hlist_nulls_head *hptr;
323 unsigned int sequence, hsz;
326 sequence = read_seqcount_begin(&nf_conntrack_generation);
327 hsz = nf_conntrack_htable_size;
328 hptr = nf_conntrack_hash;
329 } while (read_seqcount_retry(&nf_conntrack_generation, sequence));
335 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
336 const struct nf_conntrack_zone *zone,
338 void nf_ct_tmpl_free(struct nf_conn *tmpl);
340 #define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count)
341 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
342 #define NF_CT_STAT_ADD_ATOMIC(net, count, v) this_cpu_add((net)->ct.stat->count, (v))
344 #define MODULE_ALIAS_NFCT_HELPER(helper) \
345 MODULE_ALIAS("nfct-helper-" helper)
347 #endif /* _NF_CONNTRACK_H */