]> git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blame - include/linux/netfilter.h
netfilter: reduce NF_HOOK by one argument
[mirror_ubuntu-zesty-kernel.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
LT
15#include <linux/compiler.h>
16
17/* Responses from hook functions. */
18#define NF_DROP 0
19#define NF_ACCEPT 1
20#define NF_STOLEN 2
21#define NF_QUEUE 3
22#define NF_REPEAT 4
23#define NF_STOP 5
24#define NF_MAX_VERDICT NF_STOP
25
0ab43f84
HW
26/* we overload the higher bits for encoding auxiliary data such as the queue
27 * number. Not nice, but better than additional function arguments. */
28#define NF_VERDICT_MASK 0x0000ffff
29#define NF_VERDICT_BITS 16
30
31#define NF_VERDICT_QMASK 0xffff0000
32#define NF_VERDICT_QBITS 16
33
fbabbed8 34#define NF_QUEUE_NR(x) ((((x) << NF_VERDICT_BITS) & NF_VERDICT_QMASK) | NF_QUEUE)
0ab43f84 35
6869c4d8
HW
36/* only for userspace compatibility */
37#ifndef __KERNEL__
1da177e4
LT
38/* Generic cache responses from hook functions.
39 <= 0x2000 is used for protocol-flags. */
40#define NFC_UNKNOWN 0x4000
41#define NFC_ALTERED 0x8000
6869c4d8 42#endif
1da177e4 43
6e23ae2a
PM
44enum nf_inet_hooks {
45 NF_INET_PRE_ROUTING,
46 NF_INET_LOCAL_IN,
47 NF_INET_FORWARD,
48 NF_INET_LOCAL_OUT,
49 NF_INET_POST_ROUTING,
50 NF_INET_NUMHOOKS
51};
52
7e9c6eeb
JE
53enum {
54 NFPROTO_UNSPEC = 0,
55 NFPROTO_IPV4 = 2,
56 NFPROTO_ARP = 3,
57 NFPROTO_BRIDGE = 7,
58 NFPROTO_IPV6 = 10,
59 NFPROTO_DECNET = 12,
60 NFPROTO_NUMPROTO,
61};
62
643a2c15 63union nf_inet_addr {
7b33ed22 64 __u32 all[4];
643a2c15
JE
65 __be32 ip;
66 __be32 ip6[4];
2e3075a2
JE
67 struct in_addr in;
68 struct in6_addr in6;
643a2c15
JE
69};
70
1da177e4 71#ifdef __KERNEL__
1da177e4
LT
72#ifdef CONFIG_NETFILTER
73
b8beedd2
PM
74static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1,
75 const union nf_inet_addr *a2)
76{
77 return a1->all[0] == a2->all[0] &&
78 a1->all[1] == a2->all[1] &&
79 a1->all[2] == a2->all[2] &&
80 a1->all[3] == a2->all[3];
81}
82
1da177e4
LT
83extern void netfilter_init(void);
84
85/* Largest hook number + 1 */
86#define NF_MAX_HOOKS 8
87
88struct sk_buff;
1da177e4
LT
89
90typedef unsigned int nf_hookfn(unsigned int hooknum,
3db05fea 91 struct sk_buff *skb,
1da177e4
LT
92 const struct net_device *in,
93 const struct net_device *out,
94 int (*okfn)(struct sk_buff *));
95
d94d9fee 96struct nf_hook_ops {
1da177e4
LT
97 struct list_head list;
98
99 /* User fills in from here down. */
100 nf_hookfn *hook;
101 struct module *owner;
76108cea
JE
102 u_int8_t pf;
103 unsigned int hooknum;
1da177e4
LT
104 /* Hooks are ordered in ascending priority. */
105 int priority;
106};
107
d94d9fee 108struct nf_sockopt_ops {
1da177e4
LT
109 struct list_head list;
110
76108cea 111 u_int8_t pf;
1da177e4
LT
112
113 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
114 int set_optmin;
115 int set_optmax;
116 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);
c30f540b 117#ifdef CONFIG_COMPAT
3fdadf7d
DM
118 int (*compat_set)(struct sock *sk, int optval,
119 void __user *user, unsigned int len);
c30f540b 120#endif
1da177e4
LT
121 int get_optmin;
122 int get_optmax;
123 int (*get)(struct sock *sk, int optval, void __user *user, int *len);
c30f540b 124#ifdef CONFIG_COMPAT
3fdadf7d
DM
125 int (*compat_get)(struct sock *sk, int optval,
126 void __user *user, int *len);
c30f540b 127#endif
16fcec35
NH
128 /* Use the module struct to lock set/get code in place */
129 struct module *owner;
1da177e4
LT
130};
131
1da177e4
LT
132/* Function to register/unregister hook points. */
133int nf_register_hook(struct nf_hook_ops *reg);
134void nf_unregister_hook(struct nf_hook_ops *reg);
972d1cb1
PM
135int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
136void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n);
1da177e4
LT
137
138/* Functions to register get/setsockopt ranges (non-inclusive). You
139 need to check permissions yourself! */
140int nf_register_sockopt(struct nf_sockopt_ops *reg);
141void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
142
d62f9ed4
PM
143#ifdef CONFIG_SYSCTL
144/* Sysctl registration */
b3fd3ffe
PE
145extern struct ctl_path nf_net_netfilter_sysctl_path[];
146extern struct ctl_path nf_net_ipv4_netfilter_sysctl_path[];
d62f9ed4
PM
147#endif /* CONFIG_SYSCTL */
148
7e9c6eeb 149extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
1da177e4 150
76108cea 151int nf_hook_slow(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
16a6677f
PM
152 struct net_device *indev, struct net_device *outdev,
153 int (*okfn)(struct sk_buff *), int thresh);
154
155/**
156 * nf_hook_thresh - call a netfilter hook
157 *
158 * Returns 1 if the hook has allowed the packet to pass. The function
159 * okfn must be invoked by the caller in this case. Any other return
160 * value indicates the packet has been consumed by the hook.
161 */
76108cea 162static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
3db05fea 163 struct sk_buff *skb,
16a6677f
PM
164 struct net_device *indev,
165 struct net_device *outdev,
23f3733d 166 int (*okfn)(struct sk_buff *), int thresh)
16a6677f
PM
167{
168#ifndef CONFIG_NETFILTER_DEBUG
169 if (list_empty(&nf_hooks[pf][hook]))
170 return 1;
171#endif
3db05fea 172 return nf_hook_slow(pf, hook, skb, indev, outdev, okfn, thresh);
16a6677f
PM
173}
174
76108cea 175static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
16a6677f
PM
176 struct net_device *indev, struct net_device *outdev,
177 int (*okfn)(struct sk_buff *))
178{
23f3733d 179 return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN);
16a6677f 180}
1da177e4
LT
181
182/* Activate hook; either okfn or kfree_skb called, unless a hook
183 returns NF_STOLEN (in which case, it's up to the hook to deal with
184 the consequences).
185
186 Returns -ERRNO if packet dropped. Zero means queued, stolen or
187 accepted.
188*/
189
190/* RR:
191 > I don't want nf_hook to return anything because people might forget
192 > about async and trust the return value to mean "packet was ok".
193
194 AK:
195 Just document it clearly, then you can expect some sense from kernel
196 coders :)
197*/
198
199/* This is gross, but inline doesn't cut it for avoiding the function
200 call in fast path: gcc doesn't inline (needs value tracking?). --RR */
16a6677f
PM
201
202/* HX: It's slightly less gross now. */
203
1da177e4
LT
204#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \
205({int __ret; \
23f3733d 206if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, thresh)) == 1)\
48d5cad8
PM
207 __ret = (okfn)(skb); \
208__ret;})
209
210#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) \
211({int __ret; \
23f3733d 212if ((cond) || (__ret = nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN)) == 1)\
1da177e4
LT
213 __ret = (okfn)(skb); \
214__ret;})
1da177e4 215
16a6677f
PM
216#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
217 NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN)
1da177e4
LT
218
219/* Call setsockopt() */
76108cea 220int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
b7058842 221 unsigned int len);
76108cea 222int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
1da177e4 223 int *len);
c30f540b 224#ifdef CONFIG_COMPAT
76108cea 225int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval,
b7058842 226 char __user *opt, unsigned int len);
76108cea 227int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval,
3fdadf7d 228 char __user *opt, int *len);
c30f540b 229#endif
3fdadf7d 230
089af26c
HW
231/* Call this before modifying an existing packet: ensures it is
232 modifiable and linear to the point you care about (writable_len).
233 Returns true or false. */
37d41879 234extern int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
089af26c 235
1841a4c7 236struct flowi;
02f014d8 237struct nf_queue_entry;
c01cd429 238
bce8032e
PM
239struct nf_afinfo {
240 unsigned short family;
b51655b9 241 __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook,
422c346f 242 unsigned int dataoff, u_int8_t protocol);
d63a6507
PM
243 __sum16 (*checksum_partial)(struct sk_buff *skb,
244 unsigned int hook,
245 unsigned int dataoff,
246 unsigned int len,
247 u_int8_t protocol);
1841a4c7 248 int (*route)(struct dst_entry **dst, struct flowi *fl);
bce8032e 249 void (*saveroute)(const struct sk_buff *skb,
02f014d8 250 struct nf_queue_entry *entry);
3db05fea 251 int (*reroute)(struct sk_buff *skb,
02f014d8 252 const struct nf_queue_entry *entry);
bce8032e 253 int route_key_size;
2cc7d573
HW
254};
255
7e9c6eeb 256extern const struct nf_afinfo *nf_afinfo[NFPROTO_NUMPROTO];
1e796fda 257static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family)
bce8032e
PM
258{
259 return rcu_dereference(nf_afinfo[family]);
260}
2cc7d573 261
b51655b9 262static inline __sum16
422c346f
PM
263nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
264 u_int8_t protocol, unsigned short family)
265{
1e796fda 266 const struct nf_afinfo *afinfo;
b51655b9 267 __sum16 csum = 0;
422c346f
PM
268
269 rcu_read_lock();
270 afinfo = nf_get_afinfo(family);
271 if (afinfo)
272 csum = afinfo->checksum(skb, hook, dataoff, protocol);
273 rcu_read_unlock();
274 return csum;
275}
276
d63a6507
PM
277static inline __sum16
278nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
279 unsigned int dataoff, unsigned int len,
280 u_int8_t protocol, unsigned short family)
281{
282 const struct nf_afinfo *afinfo;
283 __sum16 csum = 0;
284
285 rcu_read_lock();
286 afinfo = nf_get_afinfo(family);
287 if (afinfo)
288 csum = afinfo->checksum_partial(skb, hook, dataoff, len,
289 protocol);
290 rcu_read_unlock();
291 return csum;
292}
293
1e796fda
PM
294extern int nf_register_afinfo(const struct nf_afinfo *afinfo);
295extern void nf_unregister_afinfo(const struct nf_afinfo *afinfo);
bce8032e 296
eb9c7ebe
PM
297#include <net/flow.h>
298extern void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *);
299
300static inline void
76108cea 301nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
eb9c7ebe 302{
051578cc 303#ifdef CONFIG_NF_NAT_NEEDED
eb9c7ebe
PM
304 void (*decodefn)(struct sk_buff *, struct flowi *);
305
051578cc
PM
306 if (family == AF_INET) {
307 rcu_read_lock();
308 decodefn = rcu_dereference(ip_nat_decode_session);
309 if (decodefn)
310 decodefn(skb, fl);
311 rcu_read_unlock();
312 }
eb9c7ebe
PM
313#endif
314}
315
608c8e4f
HW
316#ifdef CONFIG_PROC_FS
317#include <linux/proc_fs.h>
318extern struct proc_dir_entry *proc_net_netfilter;
319#endif
320
1da177e4
LT
321#else /* !CONFIG_NETFILTER */
322#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
48d5cad8 323#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
76108cea 324static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
3db05fea 325 struct sk_buff *skb,
f53b61d8
DM
326 struct net_device *indev,
327 struct net_device *outdev,
23f3733d 328 int (*okfn)(struct sk_buff *), int thresh)
f53b61d8 329{
3db05fea 330 return okfn(skb);
f53b61d8 331}
76108cea 332static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
f53b61d8
DM
333 struct net_device *indev, struct net_device *outdev,
334 int (*okfn)(struct sk_buff *))
335{
9c92d348 336 return 1;
f53b61d8 337}
f53b61d8 338struct flowi;
eb9c7ebe 339static inline void
76108cea
JE
340nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
341{
342}
1da177e4
LT
343#endif /*CONFIG_NETFILTER*/
344
5f79e0f9
YK
345#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
346extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *);
347extern void nf_ct_attach(struct sk_buff *, struct sk_buff *);
de6e05c4 348extern void (*nf_ct_destroy)(struct nf_conntrack *);
5f79e0f9
YK
349#else
350static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
351#endif
352
1da177e4
LT
353#endif /*__KERNEL__*/
354#endif /*__LINUX_NETFILTER_H*/