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