netfilter: nf_ct_helper: implement variable length helper private data
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / netfilter.h
CommitLineData
1da177e4
LT
1#ifndef __LINUX_NETFILTER_H
2#define __LINUX_NETFILTER_H
3
4#ifdef __KERNEL__
5#include <linux/init.h>
1da177e4
LT
6#include <linux/skbuff.h>
7#include <linux/net.h>
8#include <linux/if.h>
2e3075a2
JE
9#include <linux/in.h>
10#include <linux/in6.h>
1da177e4
LT
11#include <linux/wait.h>
12#include <linux/list.h>
13#endif
c8942f1f 14#include <linux/types.h>
1da177e4 15#include <linux/compiler.h>
bee95250 16#include <linux/sysctl.h>
1da177e4
LT
17
18/* Responses from hook functions. */
19#define NF_DROP 0
20#define NF_ACCEPT 1
21#define NF_STOLEN 2
22#define NF_QUEUE 3
23#define NF_REPEAT 4
24#define NF_STOP 5
25#define NF_MAX_VERDICT NF_STOP
26
0ab43f84 27/* we overload the higher bits for encoding auxiliary data such as the queue
f615df76
FW
28 * number or errno values. Not nice, but better than additional function
29 * arguments. */
30#define NF_VERDICT_MASK 0x000000ff
31
32/* extra verdict flags have mask 0x0000ff00 */
94b27cc3 33#define NF_VERDICT_FLAG_QUEUE_BYPASS 0x00008000
0ab43f84 34
f615df76 35/* queue number (NF_QUEUE) or errno (NF_DROP) */
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HW
36#define NF_VERDICT_QMASK 0xffff0000
37#define NF_VERDICT_QBITS 16
38
f615df76 39#define NF_QUEUE_NR(x) ((((x) << 16) & NF_VERDICT_QMASK) | NF_QUEUE)
0ab43f84 40
f615df76 41#define NF_DROP_ERR(x) (((-x) << 16) | NF_DROP)
da683650 42
6869c4d8
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43/* only for userspace compatibility */
44#ifndef __KERNEL__
1da177e4
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45/* Generic cache responses from hook functions.
46 <= 0x2000 is used for protocol-flags. */
47#define NFC_UNKNOWN 0x4000
48#define NFC_ALTERED 0x8000
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49
50/* NF_VERDICT_BITS should be 8 now, but userspace might break if this changes */
51#define NF_VERDICT_BITS 16
6869c4d8 52#endif
1da177e4 53
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54enum nf_inet_hooks {
55 NF_INET_PRE_ROUTING,
56 NF_INET_LOCAL_IN,
57 NF_INET_FORWARD,
58 NF_INET_LOCAL_OUT,
59 NF_INET_POST_ROUTING,
60 NF_INET_NUMHOOKS
61};
62
7e9c6eeb
JE
63enum {
64 NFPROTO_UNSPEC = 0,
65 NFPROTO_IPV4 = 2,
66 NFPROTO_ARP = 3,
67 NFPROTO_BRIDGE = 7,
68 NFPROTO_IPV6 = 10,
69 NFPROTO_DECNET = 12,
70 NFPROTO_NUMPROTO,
71};
72
643a2c15 73union nf_inet_addr {
7b33ed22 74 __u32 all[4];
643a2c15
JE
75 __be32 ip;
76 __be32 ip6[4];
2e3075a2
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77 struct in_addr in;
78 struct in6_addr in6;
643a2c15
JE
79};
80
1da177e4 81#ifdef __KERNEL__
1da177e4 82#ifdef CONFIG_NETFILTER
f615df76
FW
83static inline int NF_DROP_GETERR(int verdict)
84{
85 return -(verdict >> NF_VERDICT_QBITS);
86}
1da177e4 87
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88static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1,
89 const union nf_inet_addr *a2)
90{
91 return a1->all[0] == a2->all[0] &&
92 a1->all[1] == a2->all[1] &&
93 a1->all[2] == a2->all[2] &&
94 a1->all[3] == a2->all[3];
95}
96
efdedd54
DF
97static inline void nf_inet_addr_mask(const union nf_inet_addr *a1,
98 union nf_inet_addr *result,
99 const union nf_inet_addr *mask)
100{
101 result->all[0] = a1->all[0] & mask->all[0];
102 result->all[1] = a1->all[1] & mask->all[1];
103 result->all[2] = a1->all[2] & mask->all[2];
104 result->all[3] = a1->all[3] & mask->all[3];
105}
106
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107extern void netfilter_init(void);
108
109/* Largest hook number + 1 */
110#define NF_MAX_HOOKS 8
111
112struct sk_buff;
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113
114typedef unsigned int nf_hookfn(unsigned int hooknum,
3db05fea 115 struct sk_buff *skb,
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116 const struct net_device *in,
117 const struct net_device *out,
118 int (*okfn)(struct sk_buff *));
119
d94d9fee 120struct nf_hook_ops {
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121 struct list_head list;
122
123 /* User fills in from here down. */
124 nf_hookfn *hook;
125 struct module *owner;
76108cea
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126 u_int8_t pf;
127 unsigned int hooknum;
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128 /* Hooks are ordered in ascending priority. */
129 int priority;
130};
131
d94d9fee 132struct nf_sockopt_ops {
1da177e4
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133 struct list_head list;
134
76108cea 135 u_int8_t pf;
1da177e4
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136
137 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
138 int set_optmin;
139 int set_optmax;
140 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);
c30f540b 141#ifdef CONFIG_COMPAT
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142 int (*compat_set)(struct sock *sk, int optval,
143 void __user *user, unsigned int len);
c30f540b 144#endif
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145 int get_optmin;
146 int get_optmax;
147 int (*get)(struct sock *sk, int optval, void __user *user, int *len);
c30f540b 148#ifdef CONFIG_COMPAT
3fdadf7d
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149 int (*compat_get)(struct sock *sk, int optval,
150 void __user *user, int *len);
c30f540b 151#endif
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152 /* Use the module struct to lock set/get code in place */
153 struct module *owner;
1da177e4
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154};
155
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156/* Function to register/unregister hook points. */
157int nf_register_hook(struct nf_hook_ops *reg);
158void nf_unregister_hook(struct nf_hook_ops *reg);
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159int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
160void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n);
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161
162/* Functions to register get/setsockopt ranges (non-inclusive). You
163 need to check permissions yourself! */
164int nf_register_sockopt(struct nf_sockopt_ops *reg);
165void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
166
7e9c6eeb 167extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
1da177e4 168
a2d7ec58 169#if defined(CONFIG_JUMP_LABEL)
c5905afb
IM
170#include <linux/static_key.h>
171extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
a2d7ec58
ED
172static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
173{
174 if (__builtin_constant_p(pf) &&
175 __builtin_constant_p(hook))
c5905afb 176 return static_key_false(&nf_hooks_needed[pf][hook]);
a2d7ec58
ED
177
178 return !list_empty(&nf_hooks[pf][hook]);
179}
180#else
181static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
182{
183 return !list_empty(&nf_hooks[pf][hook]);
184}
185#endif
186
76108cea 187int nf_hook_slow(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
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188 struct net_device *indev, struct net_device *outdev,
189 int (*okfn)(struct sk_buff *), int thresh);
190
191/**
192 * nf_hook_thresh - call a netfilter hook
193 *
194 * Returns 1 if the hook has allowed the packet to pass. The function
195 * okfn must be invoked by the caller in this case. Any other return
196 * value indicates the packet has been consumed by the hook.
197 */
76108cea 198static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
3db05fea 199 struct sk_buff *skb,
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200 struct net_device *indev,
201 struct net_device *outdev,
23f3733d 202 int (*okfn)(struct sk_buff *), int thresh)
16a6677f 203{
a2d7ec58
ED
204 if (nf_hooks_active(pf, hook))
205 return nf_hook_slow(pf, hook, skb, indev, outdev, okfn, thresh);
206 return 1;
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207}
208
76108cea 209static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
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210 struct net_device *indev, struct net_device *outdev,
211 int (*okfn)(struct sk_buff *))
212{
23f3733d 213 return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN);
16a6677f 214}
1da177e4
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215
216/* Activate hook; either okfn or kfree_skb called, unless a hook
217 returns NF_STOLEN (in which case, it's up to the hook to deal with
218 the consequences).
219
220 Returns -ERRNO if packet dropped. Zero means queued, stolen or
221 accepted.
222*/
223
224/* RR:
225 > I don't want nf_hook to return anything because people might forget
226 > about async and trust the return value to mean "packet was ok".
227
228 AK:
229 Just document it clearly, then you can expect some sense from kernel
230 coders :)
231*/
232
2249065f
JE
233static inline int
234NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct sk_buff *skb,
235 struct net_device *in, struct net_device *out,
236 int (*okfn)(struct sk_buff *), int thresh)
237{
238 int ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, thresh);
239 if (ret == 1)
240 ret = okfn(skb);
241 return ret;
242}
48d5cad8 243
2249065f
JE
244static inline int
245NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sk_buff *skb,
246 struct net_device *in, struct net_device *out,
247 int (*okfn)(struct sk_buff *), bool cond)
248{
4bac6b18
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249 int ret;
250
251 if (!cond ||
ac5aa2e3 252 ((ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN)) == 1))
2249065f
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253 ret = okfn(skb);
254 return ret;
255}
1da177e4 256
2249065f
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257static inline int
258NF_HOOK(uint8_t pf, unsigned int hook, struct sk_buff *skb,
259 struct net_device *in, struct net_device *out,
260 int (*okfn)(struct sk_buff *))
261{
262 return NF_HOOK_THRESH(pf, hook, skb, in, out, okfn, INT_MIN);
263}
1da177e4
LT
264
265/* Call setsockopt() */
76108cea 266int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
b7058842 267 unsigned int len);
76108cea 268int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
1da177e4 269 int *len);
c30f540b 270#ifdef CONFIG_COMPAT
76108cea 271int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval,
b7058842 272 char __user *opt, unsigned int len);
76108cea 273int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval,
3fdadf7d 274 char __user *opt, int *len);
c30f540b 275#endif
3fdadf7d 276
089af26c
HW
277/* Call this before modifying an existing packet: ensures it is
278 modifiable and linear to the point you care about (writable_len).
279 Returns true or false. */
37d41879 280extern int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
089af26c 281
1841a4c7 282struct flowi;
02f014d8 283struct nf_queue_entry;
c01cd429 284
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285struct nf_afinfo {
286 unsigned short family;
b51655b9 287 __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook,
422c346f 288 unsigned int dataoff, u_int8_t protocol);
d63a6507
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289 __sum16 (*checksum_partial)(struct sk_buff *skb,
290 unsigned int hook,
291 unsigned int dataoff,
292 unsigned int len,
293 u_int8_t protocol);
31ad3dd6 294 int (*route)(struct net *net, struct dst_entry **dst,
0fae2e77 295 struct flowi *fl, bool strict);
bce8032e 296 void (*saveroute)(const struct sk_buff *skb,
02f014d8 297 struct nf_queue_entry *entry);
3db05fea 298 int (*reroute)(struct sk_buff *skb,
02f014d8 299 const struct nf_queue_entry *entry);
bce8032e 300 int route_key_size;
2cc7d573
HW
301};
302
0e60ebe0 303extern const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO];
1e796fda 304static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family)
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305{
306 return rcu_dereference(nf_afinfo[family]);
307}
2cc7d573 308
b51655b9 309static inline __sum16
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310nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
311 u_int8_t protocol, unsigned short family)
312{
1e796fda 313 const struct nf_afinfo *afinfo;
b51655b9 314 __sum16 csum = 0;
422c346f
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315
316 rcu_read_lock();
317 afinfo = nf_get_afinfo(family);
318 if (afinfo)
319 csum = afinfo->checksum(skb, hook, dataoff, protocol);
320 rcu_read_unlock();
321 return csum;
322}
323
d63a6507
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324static inline __sum16
325nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
326 unsigned int dataoff, unsigned int len,
327 u_int8_t protocol, unsigned short family)
328{
329 const struct nf_afinfo *afinfo;
330 __sum16 csum = 0;
331
332 rcu_read_lock();
333 afinfo = nf_get_afinfo(family);
334 if (afinfo)
335 csum = afinfo->checksum_partial(skb, hook, dataoff, len,
336 protocol);
337 rcu_read_unlock();
338 return csum;
339}
340
1e796fda
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341extern int nf_register_afinfo(const struct nf_afinfo *afinfo);
342extern void nf_unregister_afinfo(const struct nf_afinfo *afinfo);
bce8032e 343
eb9c7ebe
PM
344#include <net/flow.h>
345extern void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *);
346
347static inline void
76108cea 348nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
eb9c7ebe 349{
051578cc 350#ifdef CONFIG_NF_NAT_NEEDED
eb9c7ebe
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351 void (*decodefn)(struct sk_buff *, struct flowi *);
352
051578cc
PM
353 if (family == AF_INET) {
354 rcu_read_lock();
355 decodefn = rcu_dereference(ip_nat_decode_session);
356 if (decodefn)
357 decodefn(skb, fl);
358 rcu_read_unlock();
359 }
eb9c7ebe
PM
360#endif
361}
362
608c8e4f
HW
363#ifdef CONFIG_PROC_FS
364#include <linux/proc_fs.h>
365extern struct proc_dir_entry *proc_net_netfilter;
366#endif
367
1da177e4
LT
368#else /* !CONFIG_NETFILTER */
369#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
48d5cad8 370#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
76108cea 371static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
3db05fea 372 struct sk_buff *skb,
f53b61d8
DM
373 struct net_device *indev,
374 struct net_device *outdev,
23f3733d 375 int (*okfn)(struct sk_buff *), int thresh)
f53b61d8 376{
3db05fea 377 return okfn(skb);
f53b61d8 378}
76108cea 379static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
f53b61d8
DM
380 struct net_device *indev, struct net_device *outdev,
381 int (*okfn)(struct sk_buff *))
382{
9c92d348 383 return 1;
f53b61d8 384}
f53b61d8 385struct flowi;
eb9c7ebe 386static inline void
76108cea
JE
387nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
388{
389}
1da177e4
LT
390#endif /*CONFIG_NETFILTER*/
391
5f79e0f9 392#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
0e60ebe0 393extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *) __rcu;
5f79e0f9 394extern void nf_ct_attach(struct sk_buff *, struct sk_buff *);
0e60ebe0 395extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
5f79e0f9
YK
396#else
397static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
398#endif
399
1da177e4
LT
400#endif /*__KERNEL__*/
401#endif /*__LINUX_NETFILTER_H*/