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 struct module *owner; 94 void *priv; 95 u_int8_t pf; 96 unsigned int hooknum; 97 /* Hooks are ordered in ascending priority. */ 98 int priority; 99 }; 100 101 struct nf_sockopt_ops { 102 struct list_head list; 103 104 u_int8_t pf; 105 106 /* Non-inclusive ranges: use 0/0/NULL to never get called. */ 107 int set_optmin; 108 int set_optmax; 109 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len); 110 #ifdef CONFIG_COMPAT 111 int (*compat_set)(struct sock *sk, int optval, 112 void __user *user, unsigned int len); 113 #endif 114 int get_optmin; 115 int get_optmax; 116 int (*get)(struct sock *sk, int optval, void __user *user, int *len); 117 #ifdef CONFIG_COMPAT 118 int (*compat_get)(struct sock *sk, int optval, 119 void __user *user, int *len); 120 #endif 121 /* Use the module struct to lock set/get code in place */ 122 struct module *owner; 123 }; 124 125 /* Function to register/unregister hook points. */ 126 int nf_register_net_hook(struct net *net, const struct nf_hook_ops *ops); 127 void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *ops); 128 int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg, 129 unsigned int n); 130 void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg, 131 unsigned int n); 132 133 int nf_register_hook(struct nf_hook_ops *reg); 134 void nf_unregister_hook(struct nf_hook_ops *reg); 135 int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n); 136 void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n); 137 138 /* Functions to register get/setsockopt ranges (non-inclusive). You 139 need to check permissions yourself! */ 140 int nf_register_sockopt(struct nf_sockopt_ops *reg); 141 void nf_unregister_sockopt(struct nf_sockopt_ops *reg); 142 143 #ifdef HAVE_JUMP_LABEL 144 extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; 145 146 static inline bool nf_hook_list_active(struct list_head *hook_list, 147 u_int8_t pf, unsigned int hook) 148 { 149 if (__builtin_constant_p(pf) && 150 __builtin_constant_p(hook)) 151 return static_key_false(&nf_hooks_needed[pf][hook]); 152 153 return !list_empty(hook_list); 154 } 155 #else 156 static inline bool nf_hook_list_active(struct list_head *hook_list, 157 u_int8_t pf, unsigned int hook) 158 { 159 return !list_empty(hook_list); 160 } 161 #endif 162 163 int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state); 164 165 /** 166 * nf_hook_thresh - call a netfilter hook 167 * 168 * Returns 1 if the hook has allowed the packet to pass. The function 169 * okfn must be invoked by the caller in this case. Any other return 170 * value indicates the packet has been consumed by the hook. 171 */ 172 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook, 173 struct net *net, 174 struct sock *sk, 175 struct sk_buff *skb, 176 struct net_device *indev, 177 struct net_device *outdev, 178 int (*okfn)(struct net *, struct sock *, struct sk_buff *), 179 int thresh) 180 { 181 struct list_head *hook_list = &net->nf.hooks[pf][hook]; 182 183 if (nf_hook_list_active(hook_list, pf, hook)) { 184 struct nf_hook_state state; 185 186 nf_hook_state_init(&state, hook_list, hook, thresh, 187 pf, indev, outdev, sk, net, okfn); 188 return nf_hook_slow(skb, &state); 189 } 190 return 1; 191 } 192 193 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, 194 struct sock *sk, struct sk_buff *skb, 195 struct net_device *indev, struct net_device *outdev, 196 int (*okfn)(struct net *, struct sock *, struct sk_buff *)) 197 { 198 return nf_hook_thresh(pf, hook, net, sk, skb, indev, outdev, okfn, INT_MIN); 199 } 200 201 /* Activate hook; either okfn or kfree_skb called, unless a hook 202 returns NF_STOLEN (in which case, it's up to the hook to deal with 203 the consequences). 204 205 Returns -ERRNO if packet dropped. Zero means queued, stolen or 206 accepted. 207 */ 208 209 /* RR: 210 > I don't want nf_hook to return anything because people might forget 211 > about async and trust the return value to mean "packet was ok". 212 213 AK: 214 Just document it clearly, then you can expect some sense from kernel 215 coders :) 216 */ 217 218 static inline int 219 NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, 220 struct sk_buff *skb, struct net_device *in, 221 struct net_device *out, 222 int (*okfn)(struct net *, struct sock *, struct sk_buff *), 223 int thresh) 224 { 225 int ret = nf_hook_thresh(pf, hook, net, sk, skb, in, out, okfn, thresh); 226 if (ret == 1) 227 ret = okfn(net, sk, skb); 228 return ret; 229 } 230 231 static inline int 232 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, 233 struct sk_buff *skb, struct net_device *in, struct net_device *out, 234 int (*okfn)(struct net *, struct sock *, struct sk_buff *), 235 bool cond) 236 { 237 int ret; 238 239 if (!cond || 240 ((ret = nf_hook_thresh(pf, hook, net, sk, skb, in, out, okfn, INT_MIN)) == 1)) 241 ret = okfn(net, sk, skb); 242 return ret; 243 } 244 245 static inline int 246 NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, struct sk_buff *skb, 247 struct net_device *in, struct net_device *out, 248 int (*okfn)(struct net *, struct sock *, struct sk_buff *)) 249 { 250 return NF_HOOK_THRESH(pf, hook, net, sk, skb, in, out, okfn, INT_MIN); 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 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 #define NF_HOOK(pf, hook, net, sk, skb, indev, outdev, okfn) (okfn)(net, sk, skb) 351 #define NF_HOOK_COND(pf, hook, net, sk, skb, indev, outdev, okfn, cond) (okfn)(net, sk, skb) 352 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, 353 struct sock *sk, struct sk_buff *skb, 354 struct net_device *indev, struct net_device *outdev, 355 int (*okfn)(struct net *, struct sock *, struct sk_buff *)) 356 { 357 return 1; 358 } 359 struct flowi; 360 static inline void 361 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) 362 { 363 } 364 #endif /*CONFIG_NETFILTER*/ 365 366 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 367 #include <linux/netfilter/nf_conntrack_zones_common.h> 368 369 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu; 370 void nf_ct_attach(struct sk_buff *, const struct sk_buff *); 371 extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu; 372 373 struct nf_conn; 374 enum ip_conntrack_info; 375 struct nlattr; 376 377 struct nfq_ct_hook { 378 size_t (*build_size)(const struct nf_conn *ct); 379 int (*build)(struct sk_buff *skb, struct nf_conn *ct); 380 int (*parse)(const struct nlattr *attr, struct nf_conn *ct); 381 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct, 382 u32 portid, u32 report); 383 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct, 384 enum ip_conntrack_info ctinfo, s32 off); 385 }; 386 extern struct nfq_ct_hook __rcu *nfq_ct_hook; 387 #else 388 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} 389 #endif 390 391 /** 392 * nf_skb_duplicated - TEE target has sent a packet 393 * 394 * When a xtables target sends a packet, the OUTPUT and POSTROUTING 395 * hooks are traversed again, i.e. nft and xtables are invoked recursively. 396 * 397 * This is used by xtables TEE target to prevent the duplicated skb from 398 * being duplicated again. 399 */ 400 DECLARE_PER_CPU(bool, nf_skb_duplicated); 401 402 #endif /*__LINUX_NETFILTER_H*/ 403