1 /*
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
4 * extension.
5 *
6 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
7 * - generalize L3 protocol dependent part.
8 *
9 * Derived from include/linux/netfiter_ipv4/ip_conntrack.h
10 */
11
12 #ifndef _NF_CONNTRACK_H
13 #define _NF_CONNTRACK_H
14
15 #include <linux/netfilter/nf_conntrack_common.h>
16
17 #include <linux/bitops.h>
18 #include <linux/compiler.h>
19 #include <linux/atomic.h>
20
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>
26
27 #include <net/netfilter/nf_conntrack_tuple.h>
28
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;
34 struct ip_ct_tcp tcp;
35 struct nf_ct_gre gre;
36 };
37
38 union nf_conntrack_expect_proto {
39 /* insert expect proto private data here */
40 };
41
42 #include <linux/types.h>
43 #include <linux/skbuff.h>
44 #include <linux/timer.h>
45
46 #ifdef CONFIG_NETFILTER_DEBUG
47 #define NF_CT_ASSERT(x) WARN_ON(!(x))
48 #else
49 #define NF_CT_ASSERT(x)
50 #endif
51
52 struct nf_conntrack_helper;
53
54 /* Must be kept in sync with the classes defined by helpers */
55 #define NF_CT_MAX_EXPECT_CLASSES 4
56
57 /* nf_conn feature for connections that have a helper */
58 struct nf_conn_help {
59 /* Helper. if any */
60 struct nf_conntrack_helper __rcu *helper;
61
62 struct hlist_head expectations;
63
64 /* Current number of expected connections */
65 u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
66
67 /* private helper information. */
68 char data[];
69 };
70
71 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
72 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
73
74 struct nf_conn {
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 */
77 struct nf_conntrack ct_general;
78
79 spinlock_t lock;
80
81 /* XXX should I move this to the tail ? - Y.K */
82 /* These are my tuples; original and reply */
83 struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
84
85 /* Have we seen traffic both ways yet? (bitset) */
86 unsigned long status;
87
88 /* If we were expected by an expectation, this will be it */
89 struct nf_conn *master;
90
91 /* Timer function; drops refcnt when it goes off. */
92 struct timer_list timeout;
93
94 #if defined(CONFIG_NF_CONNTRACK_MARK)
95 u_int32_t mark;
96 #endif
97
98 #ifdef CONFIG_NF_CONNTRACK_SECMARK
99 u_int32_t secmark;
100 #endif
101
102 /* Extensions */
103 struct nf_ct_ext *ext;
104 #ifdef CONFIG_NET_NS
105 struct net *ct_net;
106 #endif
107
108 /* Storage reserved for other modules, must be the last member */
109 union nf_conntrack_proto proto;
110 };
111
112 static inline struct nf_conn *
nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash * hash)113 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
114 {
115 return container_of(hash, struct nf_conn,
116 tuplehash[hash->tuple.dst.dir]);
117 }
118
nf_ct_l3num(const struct nf_conn * ct)119 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
120 {
121 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
122 }
123
nf_ct_protonum(const struct nf_conn * ct)124 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
125 {
126 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
127 }
128
129 #define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
130
131 /* get master conntrack via master expectation */
132 #define master_ct(conntr) (conntr->master)
133
134 extern struct net init_net;
135
nf_ct_net(const struct nf_conn * ct)136 static inline struct net *nf_ct_net(const struct nf_conn *ct)
137 {
138 return read_pnet(&ct->ct_net);
139 }
140
141 /* Alter reply tuple (maybe alter helper). */
142 extern void
143 nf_conntrack_alter_reply(struct nf_conn *ct,
144 const struct nf_conntrack_tuple *newreply);
145
146 /* Is this tuple taken? (ignoring any belonging to the given
147 conntrack). */
148 extern int
149 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
150 const struct nf_conn *ignored_conntrack);
151
152 /* Return conntrack_info and tuple hash for given skb. */
153 static inline struct nf_conn *
nf_ct_get(const struct sk_buff * skb,enum ip_conntrack_info * ctinfo)154 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
155 {
156 *ctinfo = skb->nfctinfo;
157 return (struct nf_conn *)skb->nfct;
158 }
159
160 /* decrement reference count on a conntrack */
nf_ct_put(struct nf_conn * ct)161 static inline void nf_ct_put(struct nf_conn *ct)
162 {
163 NF_CT_ASSERT(ct);
164 nf_conntrack_put(&ct->ct_general);
165 }
166
167 /* Protocol module loading */
168 extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
169 extern void nf_ct_l3proto_module_put(unsigned short l3proto);
170
171 /*
172 * Allocate a hashtable of hlist_head (if nulls == 0),
173 * or hlist_nulls_head (if nulls == 1)
174 */
175 extern void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
176
177 extern void nf_ct_free_hashtable(void *hash, unsigned int size);
178
179 extern struct nf_conntrack_tuple_hash *
180 __nf_conntrack_find(struct net *net, u16 zone,
181 const struct nf_conntrack_tuple *tuple);
182
183 extern int nf_conntrack_hash_check_insert(struct nf_conn *ct);
184 extern void nf_ct_delete_from_lists(struct nf_conn *ct);
185 extern void nf_ct_dying_timeout(struct nf_conn *ct);
186
187 extern void nf_conntrack_flush_report(struct net *net, u32 portid, int report);
188
189 extern bool nf_ct_get_tuplepr(const struct sk_buff *skb,
190 unsigned int nhoff, u_int16_t l3num,
191 struct nf_conntrack_tuple *tuple);
192 extern bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
193 const struct nf_conntrack_tuple *orig);
194
195 extern void __nf_ct_refresh_acct(struct nf_conn *ct,
196 enum ip_conntrack_info ctinfo,
197 const struct sk_buff *skb,
198 unsigned long extra_jiffies,
199 int do_acct);
200
201 /* Refresh conntrack for this many jiffies and do accounting */
nf_ct_refresh_acct(struct nf_conn * ct,enum ip_conntrack_info ctinfo,const struct sk_buff * skb,unsigned long extra_jiffies)202 static inline void nf_ct_refresh_acct(struct nf_conn *ct,
203 enum ip_conntrack_info ctinfo,
204 const struct sk_buff *skb,
205 unsigned long extra_jiffies)
206 {
207 __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
208 }
209
210 /* Refresh conntrack for this many jiffies */
nf_ct_refresh(struct nf_conn * ct,const struct sk_buff * skb,unsigned long extra_jiffies)211 static inline void nf_ct_refresh(struct nf_conn *ct,
212 const struct sk_buff *skb,
213 unsigned long extra_jiffies)
214 {
215 __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
216 }
217
218 extern bool __nf_ct_kill_acct(struct nf_conn *ct,
219 enum ip_conntrack_info ctinfo,
220 const struct sk_buff *skb,
221 int do_acct);
222
223 /* kill conntrack and do accounting */
nf_ct_kill_acct(struct nf_conn * ct,enum ip_conntrack_info ctinfo,const struct sk_buff * skb)224 static inline bool nf_ct_kill_acct(struct nf_conn *ct,
225 enum ip_conntrack_info ctinfo,
226 const struct sk_buff *skb)
227 {
228 return __nf_ct_kill_acct(ct, ctinfo, skb, 1);
229 }
230
231 /* kill conntrack without accounting */
nf_ct_kill(struct nf_conn * ct)232 static inline bool nf_ct_kill(struct nf_conn *ct)
233 {
234 return __nf_ct_kill_acct(ct, 0, NULL, 0);
235 }
236
237 /* These are for NAT. Icky. */
238 extern s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
239 enum ip_conntrack_dir dir,
240 u32 seq);
241
242 /* Fake conntrack entry for untracked connections */
243 DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
nf_ct_untracked_get(void)244 static inline struct nf_conn *nf_ct_untracked_get(void)
245 {
246 return &__raw_get_cpu_var(nf_conntrack_untracked);
247 }
248 extern void nf_ct_untracked_status_or(unsigned long bits);
249
250 /* Iterate over all conntracks: if iter returns true, it's deleted. */
251 extern void
252 nf_ct_iterate_cleanup(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data);
253 extern void nf_conntrack_free(struct nf_conn *ct);
254 extern struct nf_conn *
255 nf_conntrack_alloc(struct net *net, u16 zone,
256 const struct nf_conntrack_tuple *orig,
257 const struct nf_conntrack_tuple *repl,
258 gfp_t gfp);
259
nf_ct_is_template(const struct nf_conn * ct)260 static inline int nf_ct_is_template(const struct nf_conn *ct)
261 {
262 return test_bit(IPS_TEMPLATE_BIT, &ct->status);
263 }
264
265 /* It's confirmed if it is, or has been in the hash table. */
nf_ct_is_confirmed(struct nf_conn * ct)266 static inline int nf_ct_is_confirmed(struct nf_conn *ct)
267 {
268 return test_bit(IPS_CONFIRMED_BIT, &ct->status);
269 }
270
nf_ct_is_dying(struct nf_conn * ct)271 static inline int nf_ct_is_dying(struct nf_conn *ct)
272 {
273 return test_bit(IPS_DYING_BIT, &ct->status);
274 }
275
nf_ct_is_untracked(const struct nf_conn * ct)276 static inline int nf_ct_is_untracked(const struct nf_conn *ct)
277 {
278 return test_bit(IPS_UNTRACKED_BIT, &ct->status);
279 }
280
281 /* Packet is received from loopback */
nf_is_loopback_packet(const struct sk_buff * skb)282 static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
283 {
284 return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
285 }
286
287 struct kernel_param;
288
289 extern 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);
294
295 #define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count)
296 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
297
298 #define MODULE_ALIAS_NFCT_HELPER(helper) \
299 MODULE_ALIAS("nfct-helper-" helper)
300
301 #endif /* _NF_CONNTRACK_H */
302