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>
44 #include <linux/timer.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/destruct timer, 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 /* XXX should I move this to the tail ? - Y.K */
89 /* These are my tuples; original and reply */
90 struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
92 /* Have we seen traffic both ways yet? (bitset) */
95 /* Timer function; drops refcnt when it goes off. */
96 struct timer_list timeout;
98 possible_net_t ct_net;
100 /* all members below initialized via memset */
101 u8 __nfct_init_offset[0];
103 /* If we were expected by an expectation, this will be it */
104 struct nf_conn *master;
106 #if defined(CONFIG_NF_CONNTRACK_MARK)
110 #ifdef CONFIG_NF_CONNTRACK_SECMARK
115 struct nf_ct_ext *ext;
117 /* Storage reserved for other modules, must be the last member */
118 union nf_conntrack_proto proto;
121 static inline struct nf_conn *
122 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
124 return container_of(hash, struct nf_conn,
125 tuplehash[hash->tuple.dst.dir]);
128 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
130 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
133 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
135 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
138 #define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
140 /* get master conntrack via master expectation */
141 #define master_ct(conntr) (conntr->master)
143 extern struct net init_net;
145 static inline struct net *nf_ct_net(const struct nf_conn *ct)
147 return read_pnet(&ct->ct_net);
150 /* Alter reply tuple (maybe alter helper). */
151 void nf_conntrack_alter_reply(struct nf_conn *ct,
152 const struct nf_conntrack_tuple *newreply);
154 /* Is this tuple taken? (ignoring any belonging to the given
156 int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
157 const struct nf_conn *ignored_conntrack);
159 /* Return conntrack_info and tuple hash for given skb. */
160 static inline struct nf_conn *
161 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
163 *ctinfo = skb->nfctinfo;
164 return (struct nf_conn *)skb->nfct;
167 /* decrement reference count on a conntrack */
168 static inline void nf_ct_put(struct nf_conn *ct)
171 nf_conntrack_put(&ct->ct_general);
174 /* Protocol module loading */
175 int nf_ct_l3proto_try_module_get(unsigned short l3proto);
176 void nf_ct_l3proto_module_put(unsigned short l3proto);
179 * Allocate a hashtable of hlist_head (if nulls == 0),
180 * or hlist_nulls_head (if nulls == 1)
182 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
184 void nf_ct_free_hashtable(void *hash, unsigned int size);
186 int nf_conntrack_hash_check_insert(struct nf_conn *ct);
187 bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report);
189 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
190 u_int16_t l3num, struct net *net,
191 struct nf_conntrack_tuple *tuple);
192 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
193 const struct nf_conntrack_tuple *orig);
195 void __nf_ct_refresh_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
196 const struct sk_buff *skb,
197 unsigned long extra_jiffies, int do_acct);
199 /* Refresh conntrack for this many jiffies and do accounting */
200 static inline void nf_ct_refresh_acct(struct nf_conn *ct,
201 enum ip_conntrack_info ctinfo,
202 const struct sk_buff *skb,
203 unsigned long extra_jiffies)
205 __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
208 /* Refresh conntrack for this many jiffies */
209 static inline void nf_ct_refresh(struct nf_conn *ct,
210 const struct sk_buff *skb,
211 unsigned long extra_jiffies)
213 __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
216 bool __nf_ct_kill_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
217 const struct sk_buff *skb, int do_acct);
219 /* kill conntrack and do accounting */
220 static inline bool nf_ct_kill_acct(struct nf_conn *ct,
221 enum ip_conntrack_info ctinfo,
222 const struct sk_buff *skb)
224 return __nf_ct_kill_acct(ct, ctinfo, skb, 1);
227 /* kill conntrack without accounting */
228 static inline bool nf_ct_kill(struct nf_conn *ct)
230 return __nf_ct_kill_acct(ct, 0, NULL, 0);
233 /* These are for NAT. Icky. */
234 extern s32 (*nf_ct_nat_offset)(const struct nf_conn *ct,
235 enum ip_conntrack_dir dir,
238 /* Fake conntrack entry for untracked connections */
239 DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
240 static inline struct nf_conn *nf_ct_untracked_get(void)
242 return raw_cpu_ptr(&nf_conntrack_untracked);
244 void nf_ct_untracked_status_or(unsigned long bits);
246 /* Iterate over all conntracks: if iter returns true, it's deleted. */
247 void nf_ct_iterate_cleanup(struct net *net,
248 int (*iter)(struct nf_conn *i, void *data),
249 void *data, u32 portid, int report);
251 struct nf_conntrack_zone;
253 void nf_conntrack_free(struct nf_conn *ct);
254 struct nf_conn *nf_conntrack_alloc(struct net *net,
255 const struct nf_conntrack_zone *zone,
256 const struct nf_conntrack_tuple *orig,
257 const struct nf_conntrack_tuple *repl,
260 static inline int nf_ct_is_template(const struct nf_conn *ct)
262 return test_bit(IPS_TEMPLATE_BIT, &ct->status);
265 /* It's confirmed if it is, or has been in the hash table. */
266 static inline int nf_ct_is_confirmed(struct nf_conn *ct)
268 return test_bit(IPS_CONFIRMED_BIT, &ct->status);
271 static inline int nf_ct_is_dying(struct nf_conn *ct)
273 return test_bit(IPS_DYING_BIT, &ct->status);
276 static inline int nf_ct_is_untracked(const struct nf_conn *ct)
278 return test_bit(IPS_UNTRACKED_BIT, &ct->status);
281 /* Packet is received from loopback */
282 static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
284 return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
289 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
290 extern unsigned int nf_conntrack_htable_size;
291 extern unsigned int nf_conntrack_max;
292 extern unsigned int nf_conntrack_hash_rnd;
293 void init_nf_conntrack_hash_rnd(void);
295 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
296 const struct nf_conntrack_zone *zone,
298 void nf_ct_tmpl_free(struct nf_conn *tmpl);
300 #define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count)
301 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
303 #define MODULE_ALIAS_NFCT_HELPER(helper) \
304 MODULE_ALIAS("nfct-helper-" helper)
306 #endif /* _NF_CONNTRACK_H */