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