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;
36 unsigned int tmpl_padto;
39 union nf_conntrack_expect_proto {
40 /* insert expect proto private data here */
43 #include <linux/types.h>
44 #include <linux/skbuff.h>
46 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
47 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
50 /* Usage count in here is 1 for hash table, 1 per skb,
51 * plus 1 for any connection(s) we are `master' for
53 * Hint, SKB address this struct and refcnt via skb->_nfct and
54 * helpers nf_conntrack_get() and nf_conntrack_put().
55 * Helper nf_ct_put() equals nf_conntrack_put() by dec refcnt,
56 * beware nf_ct_get() is different and don't inc refcnt.
58 struct nf_conntrack ct_general;
63 #ifdef CONFIG_NF_CONNTRACK_ZONES
64 struct nf_conntrack_zone zone;
66 /* XXX should I move this to the tail ? - Y.K */
67 /* These are my tuples; original and reply */
68 struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
70 /* Have we seen traffic both ways yet? (bitset) */
73 /* jiffies32 when this ct is considered dead */
76 possible_net_t ct_net;
78 #if IS_ENABLED(CONFIG_NF_NAT)
79 struct hlist_node nat_bysource;
81 /* all members below initialized via memset */
82 u8 __nfct_init_offset[0];
84 /* If we were expected by an expectation, this will be it */
85 struct nf_conn *master;
87 #if defined(CONFIG_NF_CONNTRACK_MARK)
91 #ifdef CONFIG_NF_CONNTRACK_SECMARK
96 struct nf_ct_ext *ext;
98 /* Storage reserved for other modules, must be the last member */
99 union nf_conntrack_proto proto;
102 static inline struct nf_conn *
103 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
105 return container_of(hash, struct nf_conn,
106 tuplehash[hash->tuple.dst.dir]);
109 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
111 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
114 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
116 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
119 #define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
121 /* get master conntrack via master expectation */
122 #define master_ct(conntr) (conntr->master)
124 extern struct net init_net;
126 static inline struct net *nf_ct_net(const struct nf_conn *ct)
128 return read_pnet(&ct->ct_net);
131 /* Alter reply tuple (maybe alter helper). */
132 void nf_conntrack_alter_reply(struct nf_conn *ct,
133 const struct nf_conntrack_tuple *newreply);
135 /* Is this tuple taken? (ignoring any belonging to the given
137 int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
138 const struct nf_conn *ignored_conntrack);
140 #define NFCT_INFOMASK 7UL
141 #define NFCT_PTRMASK ~(NFCT_INFOMASK)
143 /* Return conntrack_info and tuple hash for given skb. */
144 static inline struct nf_conn *
145 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
147 *ctinfo = skb->_nfct & NFCT_INFOMASK;
149 return (struct nf_conn *)(skb->_nfct & NFCT_PTRMASK);
152 /* decrement reference count on a conntrack */
153 static inline void nf_ct_put(struct nf_conn *ct)
156 nf_conntrack_put(&ct->ct_general);
159 /* Protocol module loading */
160 int nf_ct_l3proto_try_module_get(unsigned short l3proto);
161 void nf_ct_l3proto_module_put(unsigned short l3proto);
163 /* load module; enable/disable conntrack in this namespace */
164 int nf_ct_netns_get(struct net *net, u8 nfproto);
165 void nf_ct_netns_put(struct net *net, u8 nfproto);
168 * Allocate a hashtable of hlist_head (if nulls == 0),
169 * or hlist_nulls_head (if nulls == 1)
171 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
173 void nf_ct_free_hashtable(void *hash, unsigned int size);
175 int nf_conntrack_hash_check_insert(struct nf_conn *ct);
176 bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report);
178 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
179 u_int16_t l3num, struct net *net,
180 struct nf_conntrack_tuple *tuple);
181 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
182 const struct nf_conntrack_tuple *orig);
184 void __nf_ct_refresh_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
185 const struct sk_buff *skb,
186 unsigned long extra_jiffies, int do_acct);
188 /* Refresh conntrack for this many jiffies and do accounting */
189 static inline void nf_ct_refresh_acct(struct nf_conn *ct,
190 enum ip_conntrack_info ctinfo,
191 const struct sk_buff *skb,
192 unsigned long extra_jiffies)
194 __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
197 /* Refresh conntrack for this many jiffies */
198 static inline void nf_ct_refresh(struct nf_conn *ct,
199 const struct sk_buff *skb,
200 unsigned long extra_jiffies)
202 __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
205 /* kill conntrack and do accounting */
206 bool nf_ct_kill_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
207 const struct sk_buff *skb);
209 /* kill conntrack without accounting */
210 static inline bool nf_ct_kill(struct nf_conn *ct)
212 return nf_ct_delete(ct, 0, 0);
215 /* These are for NAT. Icky. */
216 extern s32 (*nf_ct_nat_offset)(const struct nf_conn *ct,
217 enum ip_conntrack_dir dir,
220 /* Set all unconfirmed conntrack as dying */
221 void nf_ct_unconfirmed_destroy(struct net *);
223 /* Iterate over all conntracks: if iter returns true, it's deleted. */
224 void nf_ct_iterate_cleanup_net(struct net *net,
225 int (*iter)(struct nf_conn *i, void *data),
226 void *data, u32 portid, int report);
228 /* also set unconfirmed conntracks as dying. Only use in module exit path. */
229 void nf_ct_iterate_destroy(int (*iter)(struct nf_conn *i, void *data),
232 struct nf_conntrack_zone;
234 void nf_conntrack_free(struct nf_conn *ct);
235 struct nf_conn *nf_conntrack_alloc(struct net *net,
236 const struct nf_conntrack_zone *zone,
237 const struct nf_conntrack_tuple *orig,
238 const struct nf_conntrack_tuple *repl,
241 static inline int nf_ct_is_template(const struct nf_conn *ct)
243 return test_bit(IPS_TEMPLATE_BIT, &ct->status);
246 /* It's confirmed if it is, or has been in the hash table. */
247 static inline int nf_ct_is_confirmed(const struct nf_conn *ct)
249 return test_bit(IPS_CONFIRMED_BIT, &ct->status);
252 static inline int nf_ct_is_dying(const struct nf_conn *ct)
254 return test_bit(IPS_DYING_BIT, &ct->status);
257 /* Packet is received from loopback */
258 static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
260 return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
263 #define nfct_time_stamp ((u32)(jiffies))
265 /* jiffies until ct expires, 0 if already expired */
266 static inline unsigned long nf_ct_expires(const struct nf_conn *ct)
268 s32 timeout = ct->timeout - nfct_time_stamp;
270 return timeout > 0 ? timeout : 0;
273 static inline bool nf_ct_is_expired(const struct nf_conn *ct)
275 return (__s32)(ct->timeout - nfct_time_stamp) <= 0;
278 /* use after obtaining a reference count */
279 static inline bool nf_ct_should_gc(const struct nf_conn *ct)
281 return nf_ct_is_expired(ct) && nf_ct_is_confirmed(ct) &&
287 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
288 int nf_conntrack_hash_resize(unsigned int hashsize);
290 extern struct hlist_nulls_head *nf_conntrack_hash;
291 extern unsigned int nf_conntrack_htable_size;
292 extern seqcount_t nf_conntrack_generation;
293 extern unsigned int nf_conntrack_max;
295 /* must be called with rcu read lock held */
297 nf_conntrack_get_ht(struct hlist_nulls_head **hash, unsigned int *hsize)
299 struct hlist_nulls_head *hptr;
300 unsigned int sequence, hsz;
303 sequence = read_seqcount_begin(&nf_conntrack_generation);
304 hsz = nf_conntrack_htable_size;
305 hptr = nf_conntrack_hash;
306 } while (read_seqcount_retry(&nf_conntrack_generation, sequence));
312 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
313 const struct nf_conntrack_zone *zone,
315 void nf_ct_tmpl_free(struct nf_conn *tmpl);
318 nf_ct_set(struct sk_buff *skb, struct nf_conn *ct, enum ip_conntrack_info info)
320 skb->_nfct = (unsigned long)ct | info;
323 #define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count)
324 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
325 #define NF_CT_STAT_ADD_ATOMIC(net, count, v) this_cpu_add((net)->ct.stat->count, (v))
327 #define MODULE_ALIAS_NFCT_HELPER(helper) \
328 MODULE_ALIAS("nfct-helper-" helper)
330 #endif /* _NF_CONNTRACK_H */