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;
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 #ifdef CONFIG_NETFILTER_DEBUG
48 #define NF_CT_ASSERT(x) WARN_ON(!(x))
50 #define NF_CT_ASSERT(x)
53 struct nf_conntrack_helper;
55 /* Must be kept in sync with the classes defined by helpers */
56 #define NF_CT_MAX_EXPECT_CLASSES 4
58 /* nf_conn feature for connections that have a helper */
61 struct nf_conntrack_helper __rcu *helper;
63 struct hlist_head expectations;
65 /* Current number of expected connections */
66 u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
68 /* private helper information. */
72 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
73 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
76 /* Usage count in here is 1 for hash table, 1 per skb,
77 * plus 1 for any connection(s) we are `master' for
79 * Hint, SKB address this struct and refcnt via skb->_nfct and
80 * helpers nf_conntrack_get() and nf_conntrack_put().
81 * Helper nf_ct_put() equals nf_conntrack_put() by dec refcnt,
82 * beware nf_ct_get() is different and don't inc refcnt.
84 struct nf_conntrack ct_general;
89 #ifdef CONFIG_NF_CONNTRACK_ZONES
90 struct nf_conntrack_zone zone;
92 /* XXX should I move this to the tail ? - Y.K */
93 /* These are my tuples; original and reply */
94 struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
96 /* Have we seen traffic both ways yet? (bitset) */
99 /* jiffies32 when this ct is considered dead */
102 possible_net_t ct_net;
104 #if IS_ENABLED(CONFIG_NF_NAT)
105 struct rhlist_head nat_bysource;
107 /* all members below initialized via memset */
108 u8 __nfct_init_offset[0];
110 /* If we were expected by an expectation, this will be it */
111 struct nf_conn *master;
113 #if defined(CONFIG_NF_CONNTRACK_MARK)
117 #ifdef CONFIG_NF_CONNTRACK_SECMARK
122 struct nf_ct_ext *ext;
124 /* Storage reserved for other modules, must be the last member */
125 union nf_conntrack_proto proto;
128 static inline struct nf_conn *
129 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
131 return container_of(hash, struct nf_conn,
132 tuplehash[hash->tuple.dst.dir]);
135 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
137 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
140 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
142 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
145 #define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
147 /* get master conntrack via master expectation */
148 #define master_ct(conntr) (conntr->master)
150 extern struct net init_net;
152 static inline struct net *nf_ct_net(const struct nf_conn *ct)
154 return read_pnet(&ct->ct_net);
157 /* Alter reply tuple (maybe alter helper). */
158 void nf_conntrack_alter_reply(struct nf_conn *ct,
159 const struct nf_conntrack_tuple *newreply);
161 /* Is this tuple taken? (ignoring any belonging to the given
163 int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
164 const struct nf_conn *ignored_conntrack);
166 #define NFCT_INFOMASK 7UL
167 #define NFCT_PTRMASK ~(NFCT_INFOMASK)
169 /* Return conntrack_info and tuple hash for given skb. */
170 static inline struct nf_conn *
171 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
173 *ctinfo = skb->_nfct & NFCT_INFOMASK;
175 return (struct nf_conn *)(skb->_nfct & NFCT_PTRMASK);
178 /* decrement reference count on a conntrack */
179 static inline void nf_ct_put(struct nf_conn *ct)
182 nf_conntrack_put(&ct->ct_general);
185 /* Protocol module loading */
186 int nf_ct_l3proto_try_module_get(unsigned short l3proto);
187 void nf_ct_l3proto_module_put(unsigned short l3proto);
189 /* load module; enable/disable conntrack in this namespace */
190 int nf_ct_netns_get(struct net *net, u8 nfproto);
191 void nf_ct_netns_put(struct net *net, u8 nfproto);
194 * Allocate a hashtable of hlist_head (if nulls == 0),
195 * or hlist_nulls_head (if nulls == 1)
197 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
199 void nf_ct_free_hashtable(void *hash, unsigned int size);
201 int nf_conntrack_hash_check_insert(struct nf_conn *ct);
202 bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report);
204 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
205 u_int16_t l3num, struct net *net,
206 struct nf_conntrack_tuple *tuple);
207 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
208 const struct nf_conntrack_tuple *orig);
210 void __nf_ct_refresh_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
211 const struct sk_buff *skb,
212 unsigned long extra_jiffies, int do_acct);
214 /* Refresh conntrack for this many jiffies and do accounting */
215 static inline void nf_ct_refresh_acct(struct nf_conn *ct,
216 enum ip_conntrack_info ctinfo,
217 const struct sk_buff *skb,
218 unsigned long extra_jiffies)
220 __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
223 /* Refresh conntrack for this many jiffies */
224 static inline void nf_ct_refresh(struct nf_conn *ct,
225 const struct sk_buff *skb,
226 unsigned long extra_jiffies)
228 __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
231 /* kill conntrack and do accounting */
232 bool nf_ct_kill_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
233 const struct sk_buff *skb);
235 /* kill conntrack without accounting */
236 static inline bool nf_ct_kill(struct nf_conn *ct)
238 return nf_ct_delete(ct, 0, 0);
241 /* These are for NAT. Icky. */
242 extern s32 (*nf_ct_nat_offset)(const struct nf_conn *ct,
243 enum ip_conntrack_dir dir,
246 /* Fake conntrack entry for untracked connections */
247 DECLARE_PER_CPU_ALIGNED(struct nf_conn, nf_conntrack_untracked);
248 static inline struct nf_conn *nf_ct_untracked_get(void)
250 return raw_cpu_ptr(&nf_conntrack_untracked);
252 void nf_ct_untracked_status_or(unsigned long bits);
254 /* Iterate over all conntracks: if iter returns true, it's deleted. */
255 void nf_ct_iterate_cleanup(struct net *net,
256 int (*iter)(struct nf_conn *i, void *data),
257 void *data, u32 portid, int report);
259 struct nf_conntrack_zone;
261 void nf_conntrack_free(struct nf_conn *ct);
262 struct nf_conn *nf_conntrack_alloc(struct net *net,
263 const struct nf_conntrack_zone *zone,
264 const struct nf_conntrack_tuple *orig,
265 const struct nf_conntrack_tuple *repl,
268 static inline int nf_ct_is_template(const struct nf_conn *ct)
270 return test_bit(IPS_TEMPLATE_BIT, &ct->status);
273 /* It's confirmed if it is, or has been in the hash table. */
274 static inline int nf_ct_is_confirmed(const struct nf_conn *ct)
276 return test_bit(IPS_CONFIRMED_BIT, &ct->status);
279 static inline int nf_ct_is_dying(const struct nf_conn *ct)
281 return test_bit(IPS_DYING_BIT, &ct->status);
284 static inline int nf_ct_is_untracked(const struct nf_conn *ct)
286 return test_bit(IPS_UNTRACKED_BIT, &ct->status);
289 /* Packet is received from loopback */
290 static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
292 return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
295 #define nfct_time_stamp ((u32)(jiffies))
297 /* jiffies until ct expires, 0 if already expired */
298 static inline unsigned long nf_ct_expires(const struct nf_conn *ct)
300 s32 timeout = ct->timeout - nfct_time_stamp;
302 return timeout > 0 ? timeout : 0;
305 static inline bool nf_ct_is_expired(const struct nf_conn *ct)
307 return (__s32)(ct->timeout - nfct_time_stamp) <= 0;
310 /* use after obtaining a reference count */
311 static inline bool nf_ct_should_gc(const struct nf_conn *ct)
313 return nf_ct_is_expired(ct) && nf_ct_is_confirmed(ct) &&
319 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
320 int nf_conntrack_hash_resize(unsigned int hashsize);
322 extern struct hlist_nulls_head *nf_conntrack_hash;
323 extern unsigned int nf_conntrack_htable_size;
324 extern seqcount_t nf_conntrack_generation;
325 extern unsigned int nf_conntrack_max;
327 /* must be called with rcu read lock held */
329 nf_conntrack_get_ht(struct hlist_nulls_head **hash, unsigned int *hsize)
331 struct hlist_nulls_head *hptr;
332 unsigned int sequence, hsz;
335 sequence = read_seqcount_begin(&nf_conntrack_generation);
336 hsz = nf_conntrack_htable_size;
337 hptr = nf_conntrack_hash;
338 } while (read_seqcount_retry(&nf_conntrack_generation, sequence));
344 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
345 const struct nf_conntrack_zone *zone,
347 void nf_ct_tmpl_free(struct nf_conn *tmpl);
350 nf_ct_set(struct sk_buff *skb, struct nf_conn *ct, enum ip_conntrack_info info)
352 skb->_nfct = (unsigned long)ct | info;
355 #define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count)
356 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
357 #define NF_CT_STAT_ADD_ATOMIC(net, count, v) this_cpu_add((net)->ct.stat->count, (v))
359 #define MODULE_ALIAS_NFCT_HELPER(helper) \
360 MODULE_ALIAS("nfct-helper-" helper)
362 #endif /* _NF_CONNTRACK_H */