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 <linux/static_key.h> 13 #include <linux/netfilter_defs.h> 14 #include <linux/netdevice.h> 15 #include <net/net_namespace.h> 16 17 #ifdef CONFIG_NETFILTER 18 static inline int NF_DROP_GETERR(int verdict) 19 { 20 return -(verdict >> NF_VERDICT_QBITS); 21 } 22 23 static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1, 24 const union nf_inet_addr *a2) 25 { 26 return a1->all[0] == a2->all[0] && 27 a1->all[1] == a2->all[1] && 28 a1->all[2] == a2->all[2] && 29 a1->all[3] == a2->all[3]; 30 } 31 32 static inline void nf_inet_addr_mask(const union nf_inet_addr *a1, 33 union nf_inet_addr *result, 34 const union nf_inet_addr *mask) 35 { 36 result->all[0] = a1->all[0] & mask->all[0]; 37 result->all[1] = a1->all[1] & mask->all[1]; 38 result->all[2] = a1->all[2] & mask->all[2]; 39 result->all[3] = a1->all[3] & mask->all[3]; 40 } 41 42 int netfilter_init(void); 43 44 struct sk_buff; 45 46 struct nf_hook_ops; 47 48 struct sock; 49 50 struct nf_hook_state { 51 unsigned int hook; 52 u_int8_t pf; 53 struct net_device *in; 54 struct net_device *out; 55 struct sock *sk; 56 struct net *net; 57 int (*okfn)(struct net *, struct sock *, struct sk_buff *); 58 }; 59 60 typedef unsigned int nf_hookfn(void *priv, 61 struct sk_buff *skb, 62 const struct nf_hook_state *state); 63 struct nf_hook_ops { 64 /* User fills in from here down. */ 65 nf_hookfn *hook; 66 struct net_device *dev; 67 void *priv; 68 u_int8_t pf; 69 unsigned int hooknum; 70 /* Hooks are ordered in ascending priority. */ 71 int priority; 72 }; 73 74 struct nf_hook_entry { 75 nf_hookfn *hook; 76 void *priv; 77 }; 78 79 struct nf_hook_entries { 80 u16 num_hook_entries; 81 /* padding */ 82 struct nf_hook_entry hooks[]; 83 84 /* trailer: pointers to original orig_ops of each hook. 85 * 86 * This is not part of struct nf_hook_entry since its only 87 * needed in slow path (hook register/unregister). 88 * 89 * const struct nf_hook_ops *orig_ops[] 90 */ 91 }; 92 93 static inline struct nf_hook_ops **nf_hook_entries_get_hook_ops(const struct nf_hook_entries *e) 94 { 95 unsigned int n = e->num_hook_entries; 96 const void *hook_end; 97 98 hook_end = &e->hooks[n]; /* this is *past* ->hooks[]! */ 99 100 return (struct nf_hook_ops **)hook_end; 101 } 102 103 static inline int 104 nf_hook_entry_hookfn(const struct nf_hook_entry *entry, struct sk_buff *skb, 105 struct nf_hook_state *state) 106 { 107 return entry->hook(entry->priv, skb, state); 108 } 109 110 static inline void nf_hook_state_init(struct nf_hook_state *p, 111 unsigned int hook, 112 u_int8_t pf, 113 struct net_device *indev, 114 struct net_device *outdev, 115 struct sock *sk, 116 struct net *net, 117 int (*okfn)(struct net *, struct sock *, struct sk_buff *)) 118 { 119 p->hook = hook; 120 p->pf = pf; 121 p->in = indev; 122 p->out = outdev; 123 p->sk = sk; 124 p->net = net; 125 p->okfn = okfn; 126 } 127 128 129 130 struct nf_sockopt_ops { 131 struct list_head list; 132 133 u_int8_t pf; 134 135 /* Non-inclusive ranges: use 0/0/NULL to never get called. */ 136 int set_optmin; 137 int set_optmax; 138 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len); 139 #ifdef CONFIG_COMPAT 140 int (*compat_set)(struct sock *sk, int optval, 141 void __user *user, unsigned int len); 142 #endif 143 int get_optmin; 144 int get_optmax; 145 int (*get)(struct sock *sk, int optval, void __user *user, int *len); 146 #ifdef CONFIG_COMPAT 147 int (*compat_get)(struct sock *sk, int optval, 148 void __user *user, int *len); 149 #endif 150 /* Use the module struct to lock set/get code in place */ 151 struct module *owner; 152 }; 153 154 /* Function to register/unregister hook points. */ 155 int nf_register_net_hook(struct net *net, const struct nf_hook_ops *ops); 156 void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *ops); 157 int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg, 158 unsigned int n); 159 void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg, 160 unsigned int n); 161 162 /* Functions to register get/setsockopt ranges (non-inclusive). You 163 need to check permissions yourself! */ 164 int nf_register_sockopt(struct nf_sockopt_ops *reg); 165 void nf_unregister_sockopt(struct nf_sockopt_ops *reg); 166 167 #ifdef HAVE_JUMP_LABEL 168 extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; 169 #endif 170 171 int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state, 172 const struct nf_hook_entries *e, unsigned int i); 173 174 /** 175 * nf_hook - call a netfilter hook 176 * 177 * Returns 1 if the hook has allowed the packet to pass. The function 178 * okfn must be invoked by the caller in this case. Any other return 179 * value indicates the packet has been consumed by the hook. 180 */ 181 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, 182 struct sock *sk, struct sk_buff *skb, 183 struct net_device *indev, struct net_device *outdev, 184 int (*okfn)(struct net *, struct sock *, struct sk_buff *)) 185 { 186 struct nf_hook_entries *hook_head; 187 int ret = 1; 188 189 #ifdef HAVE_JUMP_LABEL 190 if (__builtin_constant_p(pf) && 191 __builtin_constant_p(hook) && 192 !static_key_false(&nf_hooks_needed[pf][hook])) 193 return 1; 194 #endif 195 196 rcu_read_lock(); 197 hook_head = rcu_dereference(net->nf.hooks[pf][hook]); 198 if (hook_head) { 199 struct nf_hook_state state; 200 201 nf_hook_state_init(&state, hook, pf, indev, outdev, 202 sk, net, okfn); 203 204 ret = nf_hook_slow(skb, &state, hook_head, 0); 205 } 206 rcu_read_unlock(); 207 208 return ret; 209 } 210 211 /* Activate hook; either okfn or kfree_skb called, unless a hook 212 returns NF_STOLEN (in which case, it's up to the hook to deal with 213 the consequences). 214 215 Returns -ERRNO if packet dropped. Zero means queued, stolen or 216 accepted. 217 */ 218 219 /* RR: 220 > I don't want nf_hook to return anything because people might forget 221 > about async and trust the return value to mean "packet was ok". 222 223 AK: 224 Just document it clearly, then you can expect some sense from kernel 225 coders :) 226 */ 227 228 static inline int 229 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, 230 struct sk_buff *skb, struct net_device *in, struct net_device *out, 231 int (*okfn)(struct net *, struct sock *, struct sk_buff *), 232 bool cond) 233 { 234 int ret; 235 236 if (!cond || 237 ((ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn)) == 1)) 238 ret = okfn(net, sk, skb); 239 return ret; 240 } 241 242 static inline int 243 NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, struct sk_buff *skb, 244 struct net_device *in, struct net_device *out, 245 int (*okfn)(struct net *, struct sock *, struct sk_buff *)) 246 { 247 int ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn); 248 if (ret == 1) 249 ret = okfn(net, sk, skb); 250 return ret; 251 } 252 253 /* Call setsockopt() */ 254 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt, 255 unsigned int len); 256 int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt, 257 int *len); 258 #ifdef CONFIG_COMPAT 259 int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, 260 char __user *opt, unsigned int len); 261 int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, 262 char __user *opt, int *len); 263 #endif 264 265 /* Call this before modifying an existing packet: ensures it is 266 modifiable and linear to the point you care about (writable_len). 267 Returns true or false. */ 268 int skb_make_writable(struct sk_buff *skb, unsigned int writable_len); 269 270 struct flowi; 271 struct nf_queue_entry; 272 273 struct nf_afinfo { 274 unsigned short family; 275 __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook, 276 unsigned int dataoff, u_int8_t protocol); 277 __sum16 (*checksum_partial)(struct sk_buff *skb, 278 unsigned int hook, 279 unsigned int dataoff, 280 unsigned int len, 281 u_int8_t protocol); 282 int (*route)(struct net *net, struct dst_entry **dst, 283 struct flowi *fl, bool strict); 284 void (*saveroute)(const struct sk_buff *skb, 285 struct nf_queue_entry *entry); 286 int (*reroute)(struct net *net, struct sk_buff *skb, 287 const struct nf_queue_entry *entry); 288 int route_key_size; 289 }; 290 291 extern const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO]; 292 static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family) 293 { 294 return rcu_dereference(nf_afinfo[family]); 295 } 296 297 static inline __sum16 298 nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff, 299 u_int8_t protocol, unsigned short family) 300 { 301 const struct nf_afinfo *afinfo; 302 __sum16 csum = 0; 303 304 rcu_read_lock(); 305 afinfo = nf_get_afinfo(family); 306 if (afinfo) 307 csum = afinfo->checksum(skb, hook, dataoff, protocol); 308 rcu_read_unlock(); 309 return csum; 310 } 311 312 static inline __sum16 313 nf_checksum_partial(struct sk_buff *skb, unsigned int hook, 314 unsigned int dataoff, unsigned int len, 315 u_int8_t protocol, unsigned short family) 316 { 317 const struct nf_afinfo *afinfo; 318 __sum16 csum = 0; 319 320 rcu_read_lock(); 321 afinfo = nf_get_afinfo(family); 322 if (afinfo) 323 csum = afinfo->checksum_partial(skb, hook, dataoff, len, 324 protocol); 325 rcu_read_unlock(); 326 return csum; 327 } 328 329 int nf_register_afinfo(const struct nf_afinfo *afinfo); 330 void nf_unregister_afinfo(const struct nf_afinfo *afinfo); 331 332 #include <net/flow.h> 333 extern void (*nf_nat_decode_session_hook)(struct sk_buff *, struct flowi *); 334 335 static inline void 336 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) 337 { 338 #ifdef CONFIG_NF_NAT_NEEDED 339 void (*decodefn)(struct sk_buff *, struct flowi *); 340 341 rcu_read_lock(); 342 decodefn = rcu_dereference(nf_nat_decode_session_hook); 343 if (decodefn) 344 decodefn(skb, fl); 345 rcu_read_unlock(); 346 #endif 347 } 348 349 #else /* !CONFIG_NETFILTER */ 350 static inline int 351 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, 352 struct sk_buff *skb, struct net_device *in, struct net_device *out, 353 int (*okfn)(struct net *, struct sock *, struct sk_buff *), 354 bool cond) 355 { 356 return okfn(net, sk, skb); 357 } 358 359 static inline int 360 NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, 361 struct sk_buff *skb, struct net_device *in, struct net_device *out, 362 int (*okfn)(struct net *, struct sock *, struct sk_buff *)) 363 { 364 return okfn(net, sk, skb); 365 } 366 367 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, 368 struct sock *sk, struct sk_buff *skb, 369 struct net_device *indev, struct net_device *outdev, 370 int (*okfn)(struct net *, struct sock *, struct sk_buff *)) 371 { 372 return 1; 373 } 374 struct flowi; 375 static inline void 376 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) 377 { 378 } 379 #endif /*CONFIG_NETFILTER*/ 380 381 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 382 #include <linux/netfilter/nf_conntrack_zones_common.h> 383 384 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu; 385 void nf_ct_attach(struct sk_buff *, const struct sk_buff *); 386 extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu; 387 #else 388 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} 389 #endif 390 391 struct nf_conn; 392 enum ip_conntrack_info; 393 struct nlattr; 394 395 struct nfnl_ct_hook { 396 struct nf_conn *(*get_ct)(const struct sk_buff *skb, 397 enum ip_conntrack_info *ctinfo); 398 size_t (*build_size)(const struct nf_conn *ct); 399 int (*build)(struct sk_buff *skb, struct nf_conn *ct, 400 enum ip_conntrack_info ctinfo, 401 u_int16_t ct_attr, u_int16_t ct_info_attr); 402 int (*parse)(const struct nlattr *attr, struct nf_conn *ct); 403 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct, 404 u32 portid, u32 report); 405 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct, 406 enum ip_conntrack_info ctinfo, s32 off); 407 }; 408 extern struct nfnl_ct_hook __rcu *nfnl_ct_hook; 409 410 /** 411 * nf_skb_duplicated - TEE target has sent a packet 412 * 413 * When a xtables target sends a packet, the OUTPUT and POSTROUTING 414 * hooks are traversed again, i.e. nft and xtables are invoked recursively. 415 * 416 * This is used by xtables TEE target to prevent the duplicated skb from 417 * being duplicated again. 418 */ 419 DECLARE_PER_CPU(bool, nf_skb_duplicated); 420 421 #endif /*__LINUX_NETFILTER_H*/ 422