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 *
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.
82 */
83 struct nf_conntrack ct_general;
84
85 spinlock_t lock;
86 u16 cpu;
87
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];
91
92 /* Have we seen traffic both ways yet? (bitset) */
93 unsigned long status;
94
95 /* If we were expected by an expectation, this will be it */
96 struct nf_conn *master;
97
98 /* Timer function; drops refcnt when it goes off. */
99 struct timer_list timeout;
100
101 #if defined(CONFIG_NF_CONNTRACK_MARK)
102 u_int32_t mark;
103 #endif
104
105 #ifdef CONFIG_NF_CONNTRACK_SECMARK
106 u_int32_t secmark;
107 #endif
108
109 /* Extensions */
110 struct nf_ct_ext *ext;
111 #ifdef CONFIG_NET_NS
112 struct net *ct_net;
113 #endif
114
115 /* Storage reserved for other modules, must be the last member */
116 union nf_conntrack_proto proto;
117 };
118
119 static inline struct nf_conn *
nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash * hash)120 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
121 {
122 return container_of(hash, struct nf_conn,
123 tuplehash[hash->tuple.dst.dir]);
124 }
125
nf_ct_l3num(const struct nf_conn * ct)126 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
127 {
128 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
129 }
130
nf_ct_protonum(const struct nf_conn * ct)131 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
132 {
133 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
134 }
135
136 #define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
137
138 /* get master conntrack via master expectation */
139 #define master_ct(conntr) (conntr->master)
140
141 extern struct net init_net;
142
nf_ct_net(const struct nf_conn * ct)143 static inline struct net *nf_ct_net(const struct nf_conn *ct)
144 {
145 return read_pnet(&ct->ct_net);
146 }
147
148 /* Alter reply tuple (maybe alter helper). */
149 void nf_conntrack_alter_reply(struct nf_conn *ct,
150 const struct nf_conntrack_tuple *newreply);
151
152 /* Is this tuple taken? (ignoring any belonging to the given
153 conntrack). */
154 int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
155 const struct nf_conn *ignored_conntrack);
156
157 /* Return conntrack_info and tuple hash for given skb. */
158 static inline struct nf_conn *
nf_ct_get(const struct sk_buff * skb,enum ip_conntrack_info * ctinfo)159 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
160 {
161 *ctinfo = skb->nfctinfo;
162 return (struct nf_conn *)skb->nfct;
163 }
164
165 /* decrement reference count on a conntrack */
nf_ct_put(struct nf_conn * ct)166 static inline void nf_ct_put(struct nf_conn *ct)
167 {
168 NF_CT_ASSERT(ct);
169 nf_conntrack_put(&ct->ct_general);
170 }
171
172 /* Protocol module loading */
173 int nf_ct_l3proto_try_module_get(unsigned short l3proto);
174 void nf_ct_l3proto_module_put(unsigned short l3proto);
175
176 /*
177 * Allocate a hashtable of hlist_head (if nulls == 0),
178 * or hlist_nulls_head (if nulls == 1)
179 */
180 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
181
182 void nf_ct_free_hashtable(void *hash, unsigned int size);
183
184 struct nf_conntrack_tuple_hash *
185 __nf_conntrack_find(struct net *net, u16 zone,
186 const struct nf_conntrack_tuple *tuple);
187
188 int nf_conntrack_hash_check_insert(struct nf_conn *ct);
189 bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report);
190
191 void nf_conntrack_flush_report(struct net *net, u32 portid, int report);
192
193 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
194 u_int16_t l3num, struct nf_conntrack_tuple *tuple);
195 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
196 const struct nf_conntrack_tuple *orig);
197
198 void __nf_ct_refresh_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
199 const struct sk_buff *skb,
200 unsigned long extra_jiffies, int do_acct);
201
202 /* 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)203 static inline void nf_ct_refresh_acct(struct nf_conn *ct,
204 enum ip_conntrack_info ctinfo,
205 const struct sk_buff *skb,
206 unsigned long extra_jiffies)
207 {
208 __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
209 }
210
211 /* Refresh conntrack for this many jiffies */
nf_ct_refresh(struct nf_conn * ct,const struct sk_buff * skb,unsigned long extra_jiffies)212 static inline void nf_ct_refresh(struct nf_conn *ct,
213 const struct sk_buff *skb,
214 unsigned long extra_jiffies)
215 {
216 __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
217 }
218
219 bool __nf_ct_kill_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
220 const struct sk_buff *skb, int do_acct);
221
222 /* kill conntrack and do accounting */
nf_ct_kill_acct(struct nf_conn * ct,enum ip_conntrack_info ctinfo,const struct sk_buff * skb)223 static inline bool nf_ct_kill_acct(struct nf_conn *ct,
224 enum ip_conntrack_info ctinfo,
225 const struct sk_buff *skb)
226 {
227 return __nf_ct_kill_acct(ct, ctinfo, skb, 1);
228 }
229
230 /* kill conntrack without accounting */
nf_ct_kill(struct nf_conn * ct)231 static inline bool nf_ct_kill(struct nf_conn *ct)
232 {
233 return __nf_ct_kill_acct(ct, 0, NULL, 0);
234 }
235
236 /* These are for NAT. Icky. */
237 extern s32 (*nf_ct_nat_offset)(const struct nf_conn *ct,
238 enum ip_conntrack_dir dir,
239 u32 seq);
240
241 /* Fake conntrack entry for untracked connections */
242 DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
nf_ct_untracked_get(void)243 static inline struct nf_conn *nf_ct_untracked_get(void)
244 {
245 return raw_cpu_ptr(&nf_conntrack_untracked);
246 }
247 void nf_ct_untracked_status_or(unsigned long bits);
248
249 /* Iterate over all conntracks: if iter returns true, it's deleted. */
250 void nf_ct_iterate_cleanup(struct net *net,
251 int (*iter)(struct nf_conn *i, void *data),
252 void *data, u32 portid, int report);
253 void nf_conntrack_free(struct nf_conn *ct);
254 struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
255 const struct nf_conntrack_tuple *orig,
256 const struct nf_conntrack_tuple *repl,
257 gfp_t gfp);
258
nf_ct_is_template(const struct nf_conn * ct)259 static inline int nf_ct_is_template(const struct nf_conn *ct)
260 {
261 return test_bit(IPS_TEMPLATE_BIT, &ct->status);
262 }
263
264 /* It's confirmed if it is, or has been in the hash table. */
nf_ct_is_confirmed(struct nf_conn * ct)265 static inline int nf_ct_is_confirmed(struct nf_conn *ct)
266 {
267 return test_bit(IPS_CONFIRMED_BIT, &ct->status);
268 }
269
nf_ct_is_dying(struct nf_conn * ct)270 static inline int nf_ct_is_dying(struct nf_conn *ct)
271 {
272 return test_bit(IPS_DYING_BIT, &ct->status);
273 }
274
nf_ct_is_untracked(const struct nf_conn * ct)275 static inline int nf_ct_is_untracked(const struct nf_conn *ct)
276 {
277 return test_bit(IPS_UNTRACKED_BIT, &ct->status);
278 }
279
280 /* Packet is received from loopback */
nf_is_loopback_packet(const struct sk_buff * skb)281 static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
282 {
283 return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
284 }
285
286 struct kernel_param;
287
288 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
289 extern unsigned int nf_conntrack_htable_size;
290 extern unsigned int nf_conntrack_max;
291 extern unsigned int nf_conntrack_hash_rnd;
292 void init_nf_conntrack_hash_rnd(void);
293
294 void nf_conntrack_tmpl_insert(struct net *net, struct nf_conn *tmpl);
295
296 #define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count)
297 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
298
299 #define MODULE_ALIAS_NFCT_HELPER(helper) \
300 MODULE_ALIAS("nfct-helper-" helper)
301
302 #endif /* _NF_CONNTRACK_H */
303