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 #ifdef __KERNEL__
18 #include <linux/bitops.h>
19 #include <linux/compiler.h>
20 #include <asm/atomic.h>
21
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/ipv4/nf_conntrack_icmp.h>
27 #include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
28
29 #include <net/netfilter/nf_conntrack_tuple.h>
30
31 /* per conntrack: protocol private data */
32 union nf_conntrack_proto {
33 /* insert conntrack proto private data here */
34 struct nf_ct_dccp dccp;
35 struct ip_ct_sctp sctp;
36 struct ip_ct_tcp tcp;
37 struct ip_ct_icmp icmp;
38 struct nf_ct_icmpv6 icmpv6;
39 struct nf_ct_gre gre;
40 };
41
42 union nf_conntrack_expect_proto {
43 /* insert expect proto private data here */
44 };
45
46 /* Add protocol helper include file here */
47 #include <linux/netfilter/nf_conntrack_ftp.h>
48 #include <linux/netfilter/nf_conntrack_pptp.h>
49 #include <linux/netfilter/nf_conntrack_h323.h>
50 #include <linux/netfilter/nf_conntrack_sane.h>
51 #include <linux/netfilter/nf_conntrack_sip.h>
52
53 /* per conntrack: application helper private data */
54 union nf_conntrack_help {
55 /* insert conntrack helper private data (master) here */
56 struct nf_ct_ftp_master ct_ftp_info;
57 struct nf_ct_pptp_master ct_pptp_info;
58 struct nf_ct_h323_master ct_h323_info;
59 struct nf_ct_sane_master ct_sane_info;
60 struct nf_ct_sip_master ct_sip_info;
61 };
62
63 #include <linux/types.h>
64 #include <linux/skbuff.h>
65 #include <linux/timer.h>
66
67 #ifdef CONFIG_NETFILTER_DEBUG
68 #define NF_CT_ASSERT(x) WARN_ON(!(x))
69 #else
70 #define NF_CT_ASSERT(x)
71 #endif
72
73 struct nf_conntrack_helper;
74
75 /* Must be kept in sync with the classes defined by helpers */
76 #define NF_CT_MAX_EXPECT_CLASSES 3
77
78 /* nf_conn feature for connections that have a helper */
79 struct nf_conn_help {
80 /* Helper. if any */
81 struct nf_conntrack_helper *helper;
82
83 union nf_conntrack_help help;
84
85 struct hlist_head expectations;
86
87 /* Current number of expected connections */
88 u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
89 };
90
91 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
92 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
93
94 struct nf_conn
95 {
96 /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
97 plus 1 for any connection(s) we are `master' for */
98 struct nf_conntrack ct_general;
99
100 /* XXX should I move this to the tail ? - Y.K */
101 /* These are my tuples; original and reply */
102 struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
103
104 /* Have we seen traffic both ways yet? (bitset) */
105 unsigned long status;
106
107 /* If we were expected by an expectation, this will be it */
108 struct nf_conn *master;
109
110 /* Timer function; drops refcnt when it goes off. */
111 struct timer_list timeout;
112
113 #if defined(CONFIG_NF_CONNTRACK_MARK)
114 u_int32_t mark;
115 #endif
116
117 #ifdef CONFIG_NF_CONNTRACK_SECMARK
118 u_int32_t secmark;
119 #endif
120
121 /* Storage reserved for other modules: */
122 union nf_conntrack_proto proto;
123
124 /* Extensions */
125 struct nf_ct_ext *ext;
126 #ifdef CONFIG_NET_NS
127 struct net *ct_net;
128 #endif
129 struct rcu_head rcu;
130 };
131
132 static inline struct nf_conn *
nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash * hash)133 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
134 {
135 return container_of(hash, struct nf_conn,
136 tuplehash[hash->tuple.dst.dir]);
137 }
138
nf_ct_l3num(const struct nf_conn * ct)139 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
140 {
141 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
142 }
143
nf_ct_protonum(const struct nf_conn * ct)144 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
145 {
146 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
147 }
148
149 /* get master conntrack via master expectation */
150 #define master_ct(conntr) (conntr->master)
151
152 extern struct net init_net;
153
nf_ct_net(const struct nf_conn * ct)154 static inline struct net *nf_ct_net(const struct nf_conn *ct)
155 {
156 #ifdef CONFIG_NET_NS
157 return ct->ct_net;
158 #else
159 return &init_net;
160 #endif
161 }
162
163 /* Alter reply tuple (maybe alter helper). */
164 extern void
165 nf_conntrack_alter_reply(struct nf_conn *ct,
166 const struct nf_conntrack_tuple *newreply);
167
168 /* Is this tuple taken? (ignoring any belonging to the given
169 conntrack). */
170 extern int
171 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
172 const struct nf_conn *ignored_conntrack);
173
174 /* Return conntrack_info and tuple hash for given skb. */
175 static inline struct nf_conn *
nf_ct_get(const struct sk_buff * skb,enum ip_conntrack_info * ctinfo)176 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
177 {
178 *ctinfo = skb->nfctinfo;
179 return (struct nf_conn *)skb->nfct;
180 }
181
182 /* decrement reference count on a conntrack */
nf_ct_put(struct nf_conn * ct)183 static inline void nf_ct_put(struct nf_conn *ct)
184 {
185 NF_CT_ASSERT(ct);
186 nf_conntrack_put(&ct->ct_general);
187 }
188
189 /* Protocol module loading */
190 extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
191 extern void nf_ct_l3proto_module_put(unsigned short l3proto);
192
193 extern struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced);
194 extern void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced,
195 unsigned int size);
196
197 extern struct nf_conntrack_tuple_hash *
198 __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple);
199
200 extern void nf_conntrack_hash_insert(struct nf_conn *ct);
201
202 extern void nf_conntrack_flush(struct net *net, u32 pid, int report);
203
204 extern bool nf_ct_get_tuplepr(const struct sk_buff *skb,
205 unsigned int nhoff, u_int16_t l3num,
206 struct nf_conntrack_tuple *tuple);
207 extern bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
208 const struct nf_conntrack_tuple *orig);
209
210 extern void __nf_ct_refresh_acct(struct nf_conn *ct,
211 enum ip_conntrack_info ctinfo,
212 const struct sk_buff *skb,
213 unsigned long extra_jiffies,
214 int do_acct);
215
216 /* 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)217 static inline void nf_ct_refresh_acct(struct nf_conn *ct,
218 enum ip_conntrack_info ctinfo,
219 const struct sk_buff *skb,
220 unsigned long extra_jiffies)
221 {
222 __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
223 }
224
225 /* Refresh conntrack for this many jiffies */
nf_ct_refresh(struct nf_conn * ct,const struct sk_buff * skb,unsigned long extra_jiffies)226 static inline void nf_ct_refresh(struct nf_conn *ct,
227 const struct sk_buff *skb,
228 unsigned long extra_jiffies)
229 {
230 __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
231 }
232
233 extern bool __nf_ct_kill_acct(struct nf_conn *ct,
234 enum ip_conntrack_info ctinfo,
235 const struct sk_buff *skb,
236 int do_acct);
237
238 /* kill conntrack and do accounting */
nf_ct_kill_acct(struct nf_conn * ct,enum ip_conntrack_info ctinfo,const struct sk_buff * skb)239 static inline bool nf_ct_kill_acct(struct nf_conn *ct,
240 enum ip_conntrack_info ctinfo,
241 const struct sk_buff *skb)
242 {
243 return __nf_ct_kill_acct(ct, ctinfo, skb, 1);
244 }
245
246 /* kill conntrack without accounting */
nf_ct_kill(struct nf_conn * ct)247 static inline bool nf_ct_kill(struct nf_conn *ct)
248 {
249 return __nf_ct_kill_acct(ct, 0, NULL, 0);
250 }
251
252 /* These are for NAT. Icky. */
253 /* Update TCP window tracking data when NAT mangles the packet */
254 extern void nf_conntrack_tcp_update(const struct sk_buff *skb,
255 unsigned int dataoff,
256 struct nf_conn *ct,
257 int dir);
258
259 /* Fake conntrack entry for untracked connections */
260 extern struct nf_conn nf_conntrack_untracked;
261
262 /* Iterate over all conntracks: if iter returns true, it's deleted. */
263 extern void
264 nf_ct_iterate_cleanup(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data);
265 extern void nf_conntrack_free(struct nf_conn *ct);
266 extern struct nf_conn *
267 nf_conntrack_alloc(struct net *net,
268 const struct nf_conntrack_tuple *orig,
269 const struct nf_conntrack_tuple *repl,
270 gfp_t gfp);
271
272 /* It's confirmed if it is, or has been in the hash table. */
nf_ct_is_confirmed(struct nf_conn * ct)273 static inline int nf_ct_is_confirmed(struct nf_conn *ct)
274 {
275 return test_bit(IPS_CONFIRMED_BIT, &ct->status);
276 }
277
nf_ct_is_dying(struct nf_conn * ct)278 static inline int nf_ct_is_dying(struct nf_conn *ct)
279 {
280 return test_bit(IPS_DYING_BIT, &ct->status);
281 }
282
nf_ct_is_untracked(const struct sk_buff * skb)283 static inline int nf_ct_is_untracked(const struct sk_buff *skb)
284 {
285 return (skb->nfct == &nf_conntrack_untracked.ct_general);
286 }
287
288 extern int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
289 extern unsigned int nf_conntrack_htable_size;
290 extern int nf_conntrack_max;
291
292 #define NF_CT_STAT_INC(net, count) \
293 (per_cpu_ptr((net)->ct.stat, raw_smp_processor_id())->count++)
294 #define NF_CT_STAT_INC_ATOMIC(net, count) \
295 do { \
296 local_bh_disable(); \
297 per_cpu_ptr((net)->ct.stat, raw_smp_processor_id())->count++; \
298 local_bh_enable(); \
299 } while (0)
300
301 #define MODULE_ALIAS_NFCT_HELPER(helper) \
302 MODULE_ALIAS("nfct-helper-" helper)
303
304 #endif /* __KERNEL__ */
305 #endif /* _NF_CONNTRACK_H */
306