1 #ifndef __LINUX_NETFILTER_H 2 #define __LINUX_NETFILTER_H 3 4 #include <linux/init.h> 5 #include <linux/skbuff.h> 6 #include <linux/net.h> 7 #include <linux/if.h> 8 #include <linux/in.h> 9 #include <linux/in6.h> 10 #include <linux/wait.h> 11 #include <linux/list.h> 12 #include <uapi/linux/netfilter.h> 13 #ifdef CONFIG_NETFILTER 14 static inline int NF_DROP_GETERR(int verdict) 15 { 16 return -(verdict >> NF_VERDICT_QBITS); 17 } 18 19 static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1, 20 const union nf_inet_addr *a2) 21 { 22 return a1->all[0] == a2->all[0] && 23 a1->all[1] == a2->all[1] && 24 a1->all[2] == a2->all[2] && 25 a1->all[3] == a2->all[3]; 26 } 27 28 static inline void nf_inet_addr_mask(const union nf_inet_addr *a1, 29 union nf_inet_addr *result, 30 const union nf_inet_addr *mask) 31 { 32 result->all[0] = a1->all[0] & mask->all[0]; 33 result->all[1] = a1->all[1] & mask->all[1]; 34 result->all[2] = a1->all[2] & mask->all[2]; 35 result->all[3] = a1->all[3] & mask->all[3]; 36 } 37 38 int netfilter_init(void); 39 40 /* Largest hook number + 1 */ 41 #define NF_MAX_HOOKS 8 42 43 struct sk_buff; 44 45 struct nf_hook_ops; 46 typedef unsigned int nf_hookfn(const struct nf_hook_ops *ops, 47 struct sk_buff *skb, 48 const struct net_device *in, 49 const struct net_device *out, 50 int (*okfn)(struct sk_buff *)); 51 52 struct nf_hook_ops { 53 struct list_head list; 54 55 /* User fills in from here down. */ 56 nf_hookfn *hook; 57 struct module *owner; 58 void *priv; 59 u_int8_t pf; 60 unsigned int hooknum; 61 /* Hooks are ordered in ascending priority. */ 62 int priority; 63 }; 64 65 struct nf_sockopt_ops { 66 struct list_head list; 67 68 u_int8_t pf; 69 70 /* Non-inclusive ranges: use 0/0/NULL to never get called. */ 71 int set_optmin; 72 int set_optmax; 73 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len); 74 #ifdef CONFIG_COMPAT 75 int (*compat_set)(struct sock *sk, int optval, 76 void __user *user, unsigned int len); 77 #endif 78 int get_optmin; 79 int get_optmax; 80 int (*get)(struct sock *sk, int optval, void __user *user, int *len); 81 #ifdef CONFIG_COMPAT 82 int (*compat_get)(struct sock *sk, int optval, 83 void __user *user, int *len); 84 #endif 85 /* Use the module struct to lock set/get code in place */ 86 struct module *owner; 87 }; 88 89 /* Function to register/unregister hook points. */ 90 int nf_register_hook(struct nf_hook_ops *reg); 91 void nf_unregister_hook(struct nf_hook_ops *reg); 92 int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n); 93 void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n); 94 95 /* Functions to register get/setsockopt ranges (non-inclusive). You 96 need to check permissions yourself! */ 97 int nf_register_sockopt(struct nf_sockopt_ops *reg); 98 void nf_unregister_sockopt(struct nf_sockopt_ops *reg); 99 100 extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; 101 102 #if defined(CONFIG_JUMP_LABEL) 103 #include <linux/static_key.h> 104 extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; 105 static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook) 106 { 107 if (__builtin_constant_p(pf) && 108 __builtin_constant_p(hook)) 109 return static_key_false(&nf_hooks_needed[pf][hook]); 110 111 return !list_empty(&nf_hooks[pf][hook]); 112 } 113 #else 114 static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook) 115 { 116 return !list_empty(&nf_hooks[pf][hook]); 117 } 118 #endif 119 120 int nf_hook_slow(u_int8_t pf, unsigned int hook, struct sk_buff *skb, 121 struct net_device *indev, struct net_device *outdev, 122 int (*okfn)(struct sk_buff *), int thresh); 123 124 /** 125 * nf_hook_thresh - call a netfilter hook 126 * 127 * Returns 1 if the hook has allowed the packet to pass. The function 128 * okfn must be invoked by the caller in this case. Any other return 129 * value indicates the packet has been consumed by the hook. 130 */ 131 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook, 132 struct sk_buff *skb, 133 struct net_device *indev, 134 struct net_device *outdev, 135 int (*okfn)(struct sk_buff *), int thresh) 136 { 137 if (nf_hooks_active(pf, hook)) 138 return nf_hook_slow(pf, hook, skb, indev, outdev, okfn, thresh); 139 return 1; 140 } 141 142 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb, 143 struct net_device *indev, struct net_device *outdev, 144 int (*okfn)(struct sk_buff *)) 145 { 146 return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN); 147 } 148 149 /* Activate hook; either okfn or kfree_skb called, unless a hook 150 returns NF_STOLEN (in which case, it's up to the hook to deal with 151 the consequences). 152 153 Returns -ERRNO if packet dropped. Zero means queued, stolen or 154 accepted. 155 */ 156 157 /* RR: 158 > I don't want nf_hook to return anything because people might forget 159 > about async and trust the return value to mean "packet was ok". 160 161 AK: 162 Just document it clearly, then you can expect some sense from kernel 163 coders :) 164 */ 165 166 static inline int 167 NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct sk_buff *skb, 168 struct net_device *in, struct net_device *out, 169 int (*okfn)(struct sk_buff *), int thresh) 170 { 171 int ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, thresh); 172 if (ret == 1) 173 ret = okfn(skb); 174 return ret; 175 } 176 177 static inline int 178 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sk_buff *skb, 179 struct net_device *in, struct net_device *out, 180 int (*okfn)(struct sk_buff *), bool cond) 181 { 182 int ret; 183 184 if (!cond || 185 ((ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN)) == 1)) 186 ret = okfn(skb); 187 return ret; 188 } 189 190 static inline int 191 NF_HOOK(uint8_t pf, unsigned int hook, struct sk_buff *skb, 192 struct net_device *in, struct net_device *out, 193 int (*okfn)(struct sk_buff *)) 194 { 195 return NF_HOOK_THRESH(pf, hook, skb, in, out, okfn, INT_MIN); 196 } 197 198 /* Call setsockopt() */ 199 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt, 200 unsigned int len); 201 int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt, 202 int *len); 203 #ifdef CONFIG_COMPAT 204 int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, 205 char __user *opt, unsigned int len); 206 int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, 207 char __user *opt, int *len); 208 #endif 209 210 /* Call this before modifying an existing packet: ensures it is 211 modifiable and linear to the point you care about (writable_len). 212 Returns true or false. */ 213 int skb_make_writable(struct sk_buff *skb, unsigned int writable_len); 214 215 struct flowi; 216 struct nf_queue_entry; 217 218 struct nf_afinfo { 219 unsigned short family; 220 __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook, 221 unsigned int dataoff, u_int8_t protocol); 222 __sum16 (*checksum_partial)(struct sk_buff *skb, 223 unsigned int hook, 224 unsigned int dataoff, 225 unsigned int len, 226 u_int8_t protocol); 227 int (*route)(struct net *net, struct dst_entry **dst, 228 struct flowi *fl, bool strict); 229 void (*saveroute)(const struct sk_buff *skb, 230 struct nf_queue_entry *entry); 231 int (*reroute)(struct sk_buff *skb, 232 const struct nf_queue_entry *entry); 233 int route_key_size; 234 }; 235 236 extern const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO]; 237 static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family) 238 { 239 return rcu_dereference(nf_afinfo[family]); 240 } 241 242 static inline __sum16 243 nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff, 244 u_int8_t protocol, unsigned short family) 245 { 246 const struct nf_afinfo *afinfo; 247 __sum16 csum = 0; 248 249 rcu_read_lock(); 250 afinfo = nf_get_afinfo(family); 251 if (afinfo) 252 csum = afinfo->checksum(skb, hook, dataoff, protocol); 253 rcu_read_unlock(); 254 return csum; 255 } 256 257 static inline __sum16 258 nf_checksum_partial(struct sk_buff *skb, unsigned int hook, 259 unsigned int dataoff, unsigned int len, 260 u_int8_t protocol, unsigned short family) 261 { 262 const struct nf_afinfo *afinfo; 263 __sum16 csum = 0; 264 265 rcu_read_lock(); 266 afinfo = nf_get_afinfo(family); 267 if (afinfo) 268 csum = afinfo->checksum_partial(skb, hook, dataoff, len, 269 protocol); 270 rcu_read_unlock(); 271 return csum; 272 } 273 274 int nf_register_afinfo(const struct nf_afinfo *afinfo); 275 void nf_unregister_afinfo(const struct nf_afinfo *afinfo); 276 277 #include <net/flow.h> 278 extern void (*nf_nat_decode_session_hook)(struct sk_buff *, struct flowi *); 279 280 static inline void 281 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) 282 { 283 #ifdef CONFIG_NF_NAT_NEEDED 284 void (*decodefn)(struct sk_buff *, struct flowi *); 285 286 rcu_read_lock(); 287 decodefn = rcu_dereference(nf_nat_decode_session_hook); 288 if (decodefn) 289 decodefn(skb, fl); 290 rcu_read_unlock(); 291 #endif 292 } 293 294 #else /* !CONFIG_NETFILTER */ 295 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb) 296 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb) 297 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook, 298 struct sk_buff *skb, 299 struct net_device *indev, 300 struct net_device *outdev, 301 int (*okfn)(struct sk_buff *), int thresh) 302 { 303 return okfn(skb); 304 } 305 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb, 306 struct net_device *indev, struct net_device *outdev, 307 int (*okfn)(struct sk_buff *)) 308 { 309 return 1; 310 } 311 struct flowi; 312 static inline void 313 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) 314 { 315 } 316 #endif /*CONFIG_NETFILTER*/ 317 318 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 319 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu; 320 void nf_ct_attach(struct sk_buff *, const struct sk_buff *); 321 extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu; 322 323 struct nf_conn; 324 enum ip_conntrack_info; 325 struct nlattr; 326 327 struct nfq_ct_hook { 328 size_t (*build_size)(const struct nf_conn *ct); 329 int (*build)(struct sk_buff *skb, struct nf_conn *ct); 330 int (*parse)(const struct nlattr *attr, struct nf_conn *ct); 331 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct, 332 u32 portid, u32 report); 333 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct, 334 enum ip_conntrack_info ctinfo, s32 off); 335 }; 336 extern struct nfq_ct_hook __rcu *nfq_ct_hook; 337 #else 338 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} 339 #endif 340 341 #endif /*__LINUX_NETFILTER_H*/ 342