aboutsummaryrefslogtreecommitdiffstats
path: root/include/net/netfilter/nf_conntrack.h
blob: 2cc304efe7f972e515cd831054ed9ccc7b92c303 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Connection state tracking for netfilter.  This is separated from,
 * but required by, the (future) NAT layer; it can also be used by an iptables
 * extension.
 *
 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
 *	- generalize L3 protocol dependent part.
 *
 * Derived from include/linux/netfiter_ipv4/ip_conntrack.h
 */

#ifndef _NF_CONNTRACK_H
#define _NF_CONNTRACK_H

#include <linux/netfilter/nf_conntrack_common.h>

#include <linux/bitops.h>
#include <linux/compiler.h>
#include <linux/atomic.h>

#include <linux/netfilter/nf_conntrack_tcp.h>
#include <linux/netfilter/nf_conntrack_dccp.h>
#include <linux/netfilter/nf_conntrack_sctp.h>
#include <linux/netfilter/nf_conntrack_proto_gre.h>
#include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>

#include <net/netfilter/nf_conntrack_tuple.h>

struct nf_ct_udp {
	unsigned long	stream_ts;
};

/* per conntrack: protocol private data */
union nf_conntrack_proto {
	/* insert conntrack proto private data here */
	struct nf_ct_dccp dccp;
	struct ip_ct_sctp sctp;
	struct ip_ct_tcp tcp;
	struct nf_ct_udp udp;
	struct nf_ct_gre gre;
	unsigned int tmpl_padto;
};

union nf_conntrack_expect_proto {
	/* insert expect proto private data here */
};

struct nf_conntrack_net {
	unsigned int users4;
	unsigned int users6;
	unsigned int users_bridge;
};

#include <linux/types.h>
#include <linux/skbuff.h>

#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>

struct nf_conn {
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
	/* Usage count in here is 1 for hash table, 1 per skb,
	 * plus 1 for any connection(s) we are `master' for
	 *
	 * Hint, SKB address this struct and refcnt via skb->_nfct and
	 * helpers nf_conntrack_get() and nf_conntrack_put().
	 * Helper nf_ct_put() equals nf_conntrack_put() by dec refcnt,
	 * beware nf_ct_get() is different and don't inc refcnt.
	 */
	struct nf_conntrack ct_general;
#endif

	spinlock_t	lock;
	/* jiffies32 when this ct is considered dead */
	u32 timeout;

#ifdef CONFIG_NF_CONNTRACK_ZONES
	struct nf_conntrack_zone zone;
#endif
	/* XXX should I move this to the tail ? - Y.K */
	/* These are my tuples; original and reply */
	struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];

	/* Have we seen traffic both ways yet? (bitset) */
	unsigned long status;

	u16		cpu;
	possible_net_t ct_net;

#if IS_ENABLED(CONFIG_NF_NAT)
	struct hlist_node	nat_bysource;
#endif
	/* all members below initialized via memset */
	u8 __nfct_init_offset[0];

	/* If we were expected by an expectation, this will be it */
	struct nf_conn *master;

#if defined(CONFIG_NF_CONNTRACK_MARK)
	u_int32_t mark;
#endif

#ifdef CONFIG_NF_CONNTRACK_SECMARK
	u_int32_t secmark;
#endif

	/* Extensions */
	struct nf_ct_ext *ext;

	/* Storage reserved for other modules, must be the last member */
	union nf_conntrack_proto proto;
};

static inline struct nf_conn *
nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
{
	return container_of(hash, struct nf_conn,
			    tuplehash[hash->tuple.dst.dir]);
}

static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
{
	return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
}

static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
{
	return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
}

#define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)

/* get master conntrack via master expectation */
#define master_ct(conntr) (conntr->master)

extern struct net init_net;

static inline struct net *nf_ct_net(const struct nf_conn *ct)
{
	return read_pnet(&ct->ct_net);
}

/* Alter reply tuple (maybe alter helper). */
void nf_conntrack_alter_reply(struct nf_conn *ct,
			      const struct nf_conntrack_tuple *newreply);

/* Is this tuple taken? (ignoring any belonging to the given
   conntrack). */
int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
			     const struct nf_conn *ignored_conntrack);

#if IS_ENABLED(CONFIG_NF_CONNTRACK)

#define NFCT_INFOMASK	7UL
#define NFCT_PTRMASK	~(NFCT_INFOMASK)

/* Return conntrack_info and tuple hash for given skb. */
static inline struct nf_conn *
nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
{
	*ctinfo = skb->_nfct & NFCT_INFOMASK;

	return (struct nf_conn *)(skb->_nfct & NFCT_PTRMASK);
}

/* decrement reference count on a conntrack */
static inline void nf_ct_put(struct nf_conn *ct)
{
	WARN_ON(!ct);
	nf_conntrack_put(&ct->ct_general);
}

#endif

/* Protocol module loading */
int nf_ct_l3proto_try_module_get(unsigned short l3proto);
void nf_ct_l3proto_module_put(unsigned short l3proto);

/* load module; enable/disable conntrack in this namespace */
int nf_ct_netns_get(struct net *net, u8 nfproto);
void nf_ct_netns_put(struct net *net, u8 nfproto);

/*
 * Allocate a hashtable of hlist_head (if nulls == 0),
 * or hlist_nulls_head (if nulls == 1)
 */
void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);

int nf_conntrack_hash_check_insert(struct nf_conn *ct);
bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report);

bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
		       u_int16_t l3num, struct net *net,
		       struct nf_conntrack_tuple *tuple);

void __nf_ct_refresh_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
			  const struct sk_buff *skb,
			  u32 extra_jiffies, bool do_acct);

/* Refresh conntrack for this many jiffies and do accounting */
static inline void nf_ct_refresh_acct(struct nf_conn *ct,
				      enum ip_conntrack_info ctinfo,
				      const struct sk_buff *skb,
				      u32 extra_jiffies)
{
	__nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, true);
}

/* Refresh conntrack for this many jiffies */
static inline void nf_ct_refresh(struct nf_conn *ct,
				 const struct sk_buff *skb,
				 u32 extra_jiffies)
{
	__nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, false);
}

/* kill conntrack and do accounting */
bool nf_ct_kill_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
		     const struct sk_buff *skb);

/* kill conntrack without accounting */
static inline bool nf_ct_kill(struct nf_conn *ct)
{
	return nf_ct_delete(ct, 0, 0);
}

/* Set all unconfirmed conntrack as dying */
void nf_ct_unconfirmed_destroy(struct net *);

/* Iterate over all conntracks: if iter returns true, it's deleted. */
void nf_ct_iterate_cleanup_net(struct net *net,
			       int (*iter)(struct nf_conn *i, void *data),
			       void *data, u32 portid, int report);

/* also set unconfirmed conntracks as dying. Only use in module exit path. */
void nf_ct_iterate_destroy(int (*iter)(struct nf_conn *i, void *data),
			   void *data);

struct nf_conntrack_zone;

void nf_conntrack_free(struct nf_conn *ct);
struct nf_conn *nf_conntrack_alloc(struct net *net,
				   const struct nf_conntrack_zone *zone,
				   const struct nf_conntrack_tuple *orig,
				   const struct nf_conntrack_tuple *repl,
				   gfp_t gfp);

static inline int nf_ct_is_template(const struct nf_conn *ct)
{
	return test_bit(IPS_TEMPLATE_BIT, &ct->status);
}

/* It's confirmed if it is, or has been in the hash table. */
static inline int nf_ct_is_confirmed(const struct nf_conn *ct)
{
	return test_bit(IPS_CONFIRMED_BIT, &ct->status);
}

static inline int nf_ct_is_dying(const struct nf_conn *ct)
{
	return test_bit(IPS_DYING_BIT, &ct->status);
}

/* Packet is received from loopback */
static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
{
	return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
}

#define nfct_time_stamp ((u32)(jiffies))

/* jiffies until ct expires, 0 if already expired */
static inline unsigned long nf_ct_expires(const struct nf_conn *ct)
{
	s32 timeout = ct->timeout - nfct_time_stamp;

	return timeout > 0 ? timeout : 0;
}

static inline bool nf_ct_is_expired(const struct nf_conn *ct)
{
	return (__s32)(ct->timeout - nfct_time_stamp) <= 0;
}

/* use after obtaining a reference count */
static inline bool nf_ct_should_gc(const struct nf_conn *ct)
{
	return nf_ct_is_expired(ct) && nf_ct_is_confirmed(ct) &&
	       !nf_ct_is_dying(ct);
}

struct kernel_param;

int nf_conntrack_set_hashsize(const char *val, const struct kernel_param *kp);
int nf_conntrack_hash_resize(unsigned int hashsize);

extern struct hlist_nulls_head *nf_conntrack_hash;
extern unsigned int nf_conntrack_htable_size;
extern seqcount_t nf_conntrack_generation;
extern unsigned int nf_conntrack_max;

/* must be called with rcu read lock held */
static inline void
nf_conntrack_get_ht(struct hlist_nulls_head **hash, unsigned int *hsize)
{
	struct hlist_nulls_head *hptr;
	unsigned int sequence, hsz;

	do {
		sequence = read_seqcount_begin(&nf_conntrack_generation);
		hsz = nf_conntrack_htable_size;
		hptr = nf_conntrack_hash;
	} while (read_seqcount_retry(&nf_conntrack_generation, sequence));

	*hash = hptr;
	*hsize = hsz;
}

struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
				 const struct nf_conntrack_zone *zone,
				 gfp_t flags);
void nf_ct_tmpl_free(struct nf_conn *tmpl);

u32 nf_ct_get_id(const struct nf_conn *ct);

#if IS_ENABLED(CONFIG_NF_CONNTRACK)

static inline void
nf_ct_set(struct sk_buff *skb, struct nf_conn *ct, enum ip_conntrack_info info)
{
	skb->_nfct = (unsigned long)ct | info;
}

#endif

#define NF_CT_STAT_INC(net, count)	  __this_cpu_inc((net)->ct.stat->count)
#define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
#define NF_CT_STAT_ADD_ATOMIC(net, count, v) this_cpu_add((net)->ct.stat->count, (v))

#define MODULE_ALIAS_NFCT_HELPER(helper) \
        MODULE_ALIAS("nfct-helper-" helper)

#endif /* _NF_CONNTRACK_H */