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 18static inline int NF_DROP_GETERR(int verdict) 19{ 20 return -(verdict >> NF_VERDICT_QBITS); 21} 22 23static 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 32static 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 42int netfilter_init(void); 43 44struct sk_buff; 45 46struct nf_hook_ops; 47 48struct sock; 49 50struct 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 62static 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 83typedef unsigned int nf_hookfn(void *priv, 84 struct sk_buff *skb, 85 const struct nf_hook_state *state); 86 87struct 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 100struct 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. */ 125int nf_register_net_hook(struct net *net, const struct nf_hook_ops *ops); 126void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *ops); 127int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg, 128 unsigned int n); 129void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg, 130 unsigned int n); 131 132int nf_register_hook(struct nf_hook_ops *reg); 133void nf_unregister_hook(struct nf_hook_ops *reg); 134int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n); 135void 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! */ 139int nf_register_sockopt(struct nf_sockopt_ops *reg); 140void nf_unregister_sockopt(struct nf_sockopt_ops *reg); 141 142#ifdef HAVE_JUMP_LABEL 143extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; 144 145static inline bool nf_hook_list_active(struct list_head *hook_list, 146 u_int8_t pf, unsigned int hook) 147{ 148 if (__builtin_constant_p(pf) && 149 __builtin_constant_p(hook)) 150 return static_key_false(&nf_hooks_needed[pf][hook]); 151 152 return !list_empty(hook_list); 153} 154#else 155static inline bool nf_hook_list_active(struct list_head *hook_list, 156 u_int8_t pf, unsigned int hook) 157{ 158 return !list_empty(hook_list); 159} 160#endif 161 162int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state); 163 164/** 165 * nf_hook_thresh - call a netfilter hook 166 * 167 * Returns 1 if the hook has allowed the packet to pass. The function 168 * okfn must be invoked by the caller in this case. Any other return 169 * value indicates the packet has been consumed by the hook. 170 */ 171static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook, 172 struct net *net, 173 struct sock *sk, 174 struct sk_buff *skb, 175 struct net_device *indev, 176 struct net_device *outdev, 177 int (*okfn)(struct net *, struct sock *, struct sk_buff *), 178 int thresh) 179{ 180 struct list_head *hook_list = &net->nf.hooks[pf][hook]; 181 182 if (nf_hook_list_active(hook_list, pf, hook)) { 183 struct nf_hook_state state; 184 185 nf_hook_state_init(&state, hook_list, hook, thresh, 186 pf, indev, outdev, sk, net, okfn); 187 return nf_hook_slow(skb, &state); 188 } 189 return 1; 190} 191 192static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, 193 struct sock *sk, struct sk_buff *skb, 194 struct net_device *indev, struct net_device *outdev, 195 int (*okfn)(struct net *, struct sock *, struct sk_buff *)) 196{ 197 return nf_hook_thresh(pf, hook, net, sk, skb, indev, outdev, okfn, INT_MIN); 198} 199 200/* Activate hook; either okfn or kfree_skb called, unless a hook 201 returns NF_STOLEN (in which case, it's up to the hook to deal with 202 the consequences). 203 204 Returns -ERRNO if packet dropped. Zero means queued, stolen or 205 accepted. 206*/ 207 208/* RR: 209 > I don't want nf_hook to return anything because people might forget 210 > about async and trust the return value to mean "packet was ok". 211 212 AK: 213 Just document it clearly, then you can expect some sense from kernel 214 coders :) 215*/ 216 217static inline int 218NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, 219 struct sk_buff *skb, struct net_device *in, 220 struct net_device *out, 221 int (*okfn)(struct net *, struct sock *, struct sk_buff *), 222 int thresh) 223{ 224 int ret = nf_hook_thresh(pf, hook, net, sk, skb, in, out, okfn, thresh); 225 if (ret == 1) 226 ret = okfn(net, sk, skb); 227 return ret; 228} 229 230static inline int 231NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, 232 struct sk_buff *skb, struct net_device *in, struct net_device *out, 233 int (*okfn)(struct net *, struct sock *, struct sk_buff *), 234 bool cond) 235{ 236 int ret; 237 238 if (!cond || 239 ((ret = nf_hook_thresh(pf, hook, net, sk, skb, in, out, okfn, INT_MIN)) == 1)) 240 ret = okfn(net, sk, skb); 241 return ret; 242} 243 244static inline int 245NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, struct sk_buff *skb, 246 struct net_device *in, struct net_device *out, 247 int (*okfn)(struct net *, struct sock *, struct sk_buff *)) 248{ 249 return NF_HOOK_THRESH(pf, hook, net, sk, skb, in, out, okfn, INT_MIN); 250} 251 252/* Call setsockopt() */ 253int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt, 254 unsigned int len); 255int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt, 256 int *len); 257#ifdef CONFIG_COMPAT 258int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, 259 char __user *opt, unsigned int len); 260int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, 261 char __user *opt, int *len); 262#endif 263 264/* Call this before modifying an existing packet: ensures it is 265 modifiable and linear to the point you care about (writable_len). 266 Returns true or false. */ 267int skb_make_writable(struct sk_buff *skb, unsigned int writable_len); 268 269struct flowi; 270struct nf_queue_entry; 271 272struct nf_afinfo { 273 unsigned short family; 274 __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook, 275 unsigned int dataoff, u_int8_t protocol); 276 __sum16 (*checksum_partial)(struct sk_buff *skb, 277 unsigned int hook, 278 unsigned int dataoff, 279 unsigned int len, 280 u_int8_t protocol); 281 int (*route)(struct net *net, struct dst_entry **dst, 282 struct flowi *fl, bool strict); 283 void (*saveroute)(const struct sk_buff *skb, 284 struct nf_queue_entry *entry); 285 int (*reroute)(struct net *net, struct sk_buff *skb, 286 const struct nf_queue_entry *entry); 287 int route_key_size; 288}; 289 290extern const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO]; 291static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family) 292{ 293 return rcu_dereference(nf_afinfo[family]); 294} 295 296static inline __sum16 297nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff, 298 u_int8_t protocol, unsigned short family) 299{ 300 const struct nf_afinfo *afinfo; 301 __sum16 csum = 0; 302 303 rcu_read_lock(); 304 afinfo = nf_get_afinfo(family); 305 if (afinfo) 306 csum = afinfo->checksum(skb, hook, dataoff, protocol); 307 rcu_read_unlock(); 308 return csum; 309} 310 311static inline __sum16 312nf_checksum_partial(struct sk_buff *skb, unsigned int hook, 313 unsigned int dataoff, unsigned int len, 314 u_int8_t protocol, unsigned short family) 315{ 316 const struct nf_afinfo *afinfo; 317 __sum16 csum = 0; 318 319 rcu_read_lock(); 320 afinfo = nf_get_afinfo(family); 321 if (afinfo) 322 csum = afinfo->checksum_partial(skb, hook, dataoff, len, 323 protocol); 324 rcu_read_unlock(); 325 return csum; 326} 327 328int nf_register_afinfo(const struct nf_afinfo *afinfo); 329void nf_unregister_afinfo(const struct nf_afinfo *afinfo); 330 331#include <net/flow.h> 332extern void (*nf_nat_decode_session_hook)(struct sk_buff *, struct flowi *); 333 334static inline void 335nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) 336{ 337#ifdef CONFIG_NF_NAT_NEEDED 338 void (*decodefn)(struct sk_buff *, struct flowi *); 339 340 rcu_read_lock(); 341 decodefn = rcu_dereference(nf_nat_decode_session_hook); 342 if (decodefn) 343 decodefn(skb, fl); 344 rcu_read_unlock(); 345#endif 346} 347 348#else /* !CONFIG_NETFILTER */ 349static inline int 350NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, 351 struct sk_buff *skb, struct net_device *in, struct net_device *out, 352 int (*okfn)(struct net *, struct sock *, struct sk_buff *), 353 bool cond) 354{ 355 return okfn(net, sk, skb); 356} 357 358static inline int 359NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, 360 struct sk_buff *skb, struct net_device *in, struct net_device *out, 361 int (*okfn)(struct net *, struct sock *, struct sk_buff *)) 362{ 363 return okfn(net, sk, skb); 364} 365 366static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, 367 struct sock *sk, struct sk_buff *skb, 368 struct net_device *indev, struct net_device *outdev, 369 int (*okfn)(struct net *, struct sock *, struct sk_buff *)) 370{ 371 return 1; 372} 373struct flowi; 374static inline void 375nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) 376{ 377} 378#endif /*CONFIG_NETFILTER*/ 379 380#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 381#include <linux/netfilter/nf_conntrack_zones_common.h> 382 383extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu; 384void nf_ct_attach(struct sk_buff *, const struct sk_buff *); 385extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu; 386#else 387static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} 388#endif 389 390struct nf_conn; 391enum ip_conntrack_info; 392struct nlattr; 393 394struct nfnl_ct_hook { 395 struct nf_conn *(*get_ct)(const struct sk_buff *skb, 396 enum ip_conntrack_info *ctinfo); 397 size_t (*build_size)(const struct nf_conn *ct); 398 int (*build)(struct sk_buff *skb, struct nf_conn *ct, 399 enum ip_conntrack_info ctinfo, 400 u_int16_t ct_attr, u_int16_t ct_info_attr); 401 int (*parse)(const struct nlattr *attr, struct nf_conn *ct); 402 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct, 403 u32 portid, u32 report); 404 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct, 405 enum ip_conntrack_info ctinfo, s32 off); 406}; 407extern struct nfnl_ct_hook __rcu *nfnl_ct_hook; 408 409/** 410 * nf_skb_duplicated - TEE target has sent a packet 411 * 412 * When a xtables target sends a packet, the OUTPUT and POSTROUTING 413 * hooks are traversed again, i.e. nft and xtables are invoked recursively. 414 * 415 * This is used by xtables TEE target to prevent the duplicated skb from 416 * being duplicated again. 417 */ 418DECLARE_PER_CPU(bool, nf_skb_duplicated); 419 420#endif /*__LINUX_NETFILTER_H*/ 421