| 1 | #ifndef _X_TABLES_H |
| 2 | #define _X_TABLES_H |
| 3 | |
| 4 | |
| 5 | #include <linux/netdevice.h> |
| 6 | #include <uapi/linux/netfilter/x_tables.h> |
| 7 | |
| 8 | /** |
| 9 | * struct xt_action_param - parameters for matches/targets |
| 10 | * |
| 11 | * @match: the match extension |
| 12 | * @target: the target extension |
| 13 | * @matchinfo: per-match data |
| 14 | * @targetinfo: per-target data |
| 15 | * @in: input netdevice |
| 16 | * @out: output netdevice |
| 17 | * @fragoff: packet is a fragment, this is the data offset |
| 18 | * @thoff: position of transport header relative to skb->data |
| 19 | * @hook: hook number given packet came from |
| 20 | * @family: Actual NFPROTO_* through which the function is invoked |
| 21 | * (helpful when match->family == NFPROTO_UNSPEC) |
| 22 | * |
| 23 | * Fields written to by extensions: |
| 24 | * |
| 25 | * @hotdrop: drop packet if we had inspection problems |
| 26 | * Network namespace obtainable using dev_net(in/out) |
| 27 | */ |
| 28 | struct xt_action_param { |
| 29 | union { |
| 30 | const struct xt_match *match; |
| 31 | const struct xt_target *target; |
| 32 | }; |
| 33 | union { |
| 34 | const void *matchinfo, *targinfo; |
| 35 | }; |
| 36 | const struct net_device *in, *out; |
| 37 | int fragoff; |
| 38 | unsigned int thoff; |
| 39 | unsigned int hooknum; |
| 40 | u_int8_t family; |
| 41 | bool hotdrop; |
| 42 | }; |
| 43 | |
| 44 | /** |
| 45 | * struct xt_mtchk_param - parameters for match extensions' |
| 46 | * checkentry functions |
| 47 | * |
| 48 | * @net: network namespace through which the check was invoked |
| 49 | * @table: table the rule is tried to be inserted into |
| 50 | * @entryinfo: the family-specific rule data |
| 51 | * (struct ipt_ip, ip6t_ip, arpt_arp or (note) ebt_entry) |
| 52 | * @match: struct xt_match through which this function was invoked |
| 53 | * @matchinfo: per-match data |
| 54 | * @hook_mask: via which hooks the new rule is reachable |
| 55 | * Other fields as above. |
| 56 | */ |
| 57 | struct xt_mtchk_param { |
| 58 | struct net *net; |
| 59 | const char *table; |
| 60 | const void *entryinfo; |
| 61 | const struct xt_match *match; |
| 62 | void *matchinfo; |
| 63 | unsigned int hook_mask; |
| 64 | u_int8_t family; |
| 65 | }; |
| 66 | |
| 67 | /** |
| 68 | * struct xt_mdtor_param - match destructor parameters |
| 69 | * Fields as above. |
| 70 | */ |
| 71 | struct xt_mtdtor_param { |
| 72 | struct net *net; |
| 73 | const struct xt_match *match; |
| 74 | void *matchinfo; |
| 75 | u_int8_t family; |
| 76 | }; |
| 77 | |
| 78 | /** |
| 79 | * struct xt_tgchk_param - parameters for target extensions' |
| 80 | * checkentry functions |
| 81 | * |
| 82 | * @entryinfo: the family-specific rule data |
| 83 | * (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry) |
| 84 | * |
| 85 | * Other fields see above. |
| 86 | */ |
| 87 | struct xt_tgchk_param { |
| 88 | struct net *net; |
| 89 | const char *table; |
| 90 | const void *entryinfo; |
| 91 | const struct xt_target *target; |
| 92 | void *targinfo; |
| 93 | unsigned int hook_mask; |
| 94 | u_int8_t family; |
| 95 | }; |
| 96 | |
| 97 | /* Target destructor parameters */ |
| 98 | struct xt_tgdtor_param { |
| 99 | struct net *net; |
| 100 | const struct xt_target *target; |
| 101 | void *targinfo; |
| 102 | u_int8_t family; |
| 103 | }; |
| 104 | |
| 105 | struct xt_match { |
| 106 | struct list_head list; |
| 107 | |
| 108 | const char name[XT_EXTENSION_MAXNAMELEN]; |
| 109 | u_int8_t revision; |
| 110 | |
| 111 | /* Return true or false: return FALSE and set *hotdrop = 1 to |
| 112 | force immediate packet drop. */ |
| 113 | /* Arguments changed since 2.6.9, as this must now handle |
| 114 | non-linear skb, using skb_header_pointer and |
| 115 | skb_ip_make_writable. */ |
| 116 | bool (*match)(const struct sk_buff *skb, |
| 117 | struct xt_action_param *); |
| 118 | |
| 119 | /* Called when user tries to insert an entry of this type. */ |
| 120 | int (*checkentry)(const struct xt_mtchk_param *); |
| 121 | |
| 122 | /* Called when entry of this type deleted. */ |
| 123 | void (*destroy)(const struct xt_mtdtor_param *); |
| 124 | #ifdef CONFIG_COMPAT |
| 125 | /* Called when userspace align differs from kernel space one */ |
| 126 | void (*compat_from_user)(void *dst, const void *src); |
| 127 | int (*compat_to_user)(void __user *dst, const void *src); |
| 128 | #endif |
| 129 | /* Set this to THIS_MODULE if you are a module, otherwise NULL */ |
| 130 | struct module *me; |
| 131 | |
| 132 | const char *table; |
| 133 | unsigned int matchsize; |
| 134 | #ifdef CONFIG_COMPAT |
| 135 | unsigned int compatsize; |
| 136 | #endif |
| 137 | unsigned int hooks; |
| 138 | unsigned short proto; |
| 139 | |
| 140 | unsigned short family; |
| 141 | }; |
| 142 | |
| 143 | /* Registration hooks for targets. */ |
| 144 | struct xt_target { |
| 145 | struct list_head list; |
| 146 | |
| 147 | const char name[XT_EXTENSION_MAXNAMELEN]; |
| 148 | u_int8_t revision; |
| 149 | |
| 150 | /* Returns verdict. Argument order changed since 2.6.9, as this |
| 151 | must now handle non-linear skbs, using skb_copy_bits and |
| 152 | skb_ip_make_writable. */ |
| 153 | unsigned int (*target)(struct sk_buff *skb, |
| 154 | const struct xt_action_param *); |
| 155 | |
| 156 | /* Called when user tries to insert an entry of this type: |
| 157 | hook_mask is a bitmask of hooks from which it can be |
| 158 | called. */ |
| 159 | /* Should return 0 on success or an error code otherwise (-Exxxx). */ |
| 160 | int (*checkentry)(const struct xt_tgchk_param *); |
| 161 | |
| 162 | /* Called when entry of this type deleted. */ |
| 163 | void (*destroy)(const struct xt_tgdtor_param *); |
| 164 | #ifdef CONFIG_COMPAT |
| 165 | /* Called when userspace align differs from kernel space one */ |
| 166 | void (*compat_from_user)(void *dst, const void *src); |
| 167 | int (*compat_to_user)(void __user *dst, const void *src); |
| 168 | #endif |
| 169 | /* Set this to THIS_MODULE if you are a module, otherwise NULL */ |
| 170 | struct module *me; |
| 171 | |
| 172 | const char *table; |
| 173 | unsigned int targetsize; |
| 174 | #ifdef CONFIG_COMPAT |
| 175 | unsigned int compatsize; |
| 176 | #endif |
| 177 | unsigned int hooks; |
| 178 | unsigned short proto; |
| 179 | |
| 180 | unsigned short family; |
| 181 | }; |
| 182 | |
| 183 | /* Furniture shopping... */ |
| 184 | struct xt_table { |
| 185 | struct list_head list; |
| 186 | |
| 187 | /* What hooks you will enter on */ |
| 188 | unsigned int valid_hooks; |
| 189 | |
| 190 | /* Man behind the curtain... */ |
| 191 | struct xt_table_info *private; |
| 192 | |
| 193 | /* Set this to THIS_MODULE if you are a module, otherwise NULL */ |
| 194 | struct module *me; |
| 195 | |
| 196 | u_int8_t af; /* address/protocol family */ |
| 197 | int priority; /* hook order */ |
| 198 | |
| 199 | /* A unique name... */ |
| 200 | const char name[XT_TABLE_MAXNAMELEN]; |
| 201 | }; |
| 202 | |
| 203 | #include <linux/netfilter_ipv4.h> |
| 204 | |
| 205 | /* The table itself */ |
| 206 | struct xt_table_info { |
| 207 | /* Size per table */ |
| 208 | unsigned int size; |
| 209 | /* Number of entries: FIXME. --RR */ |
| 210 | unsigned int number; |
| 211 | /* Initial number of entries. Needed for module usage count */ |
| 212 | unsigned int initial_entries; |
| 213 | |
| 214 | /* Entry points and underflows */ |
| 215 | unsigned int hook_entry[NF_INET_NUMHOOKS]; |
| 216 | unsigned int underflow[NF_INET_NUMHOOKS]; |
| 217 | |
| 218 | /* |
| 219 | * Number of user chains. Since tables cannot have loops, at most |
| 220 | * @stacksize jumps (number of user chains) can possibly be made. |
| 221 | */ |
| 222 | unsigned int stacksize; |
| 223 | unsigned int __percpu *stackptr; |
| 224 | void ***jumpstack; |
| 225 | /* ipt_entry tables: one per CPU */ |
| 226 | /* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */ |
| 227 | void *entries[1]; |
| 228 | }; |
| 229 | |
| 230 | #define XT_TABLE_INFO_SZ (offsetof(struct xt_table_info, entries) \ |
| 231 | + nr_cpu_ids * sizeof(char *)) |
| 232 | extern int xt_register_target(struct xt_target *target); |
| 233 | extern void xt_unregister_target(struct xt_target *target); |
| 234 | extern int xt_register_targets(struct xt_target *target, unsigned int n); |
| 235 | extern void xt_unregister_targets(struct xt_target *target, unsigned int n); |
| 236 | |
| 237 | extern int xt_register_match(struct xt_match *target); |
| 238 | extern void xt_unregister_match(struct xt_match *target); |
| 239 | extern int xt_register_matches(struct xt_match *match, unsigned int n); |
| 240 | extern void xt_unregister_matches(struct xt_match *match, unsigned int n); |
| 241 | |
| 242 | int xt_check_entry_offsets(const void *base, const char *elems, |
| 243 | unsigned int target_offset, |
| 244 | unsigned int next_offset); |
| 245 | |
| 246 | extern int xt_check_match(struct xt_mtchk_param *, |
| 247 | unsigned int size, u_int8_t proto, bool inv_proto); |
| 248 | extern int xt_check_target(struct xt_tgchk_param *, |
| 249 | unsigned int size, u_int8_t proto, bool inv_proto); |
| 250 | |
| 251 | void *xt_copy_counters_from_user(const void __user *user, unsigned int len, |
| 252 | struct xt_counters_info *info, bool compat); |
| 253 | |
| 254 | extern struct xt_table *xt_register_table(struct net *net, |
| 255 | const struct xt_table *table, |
| 256 | struct xt_table_info *bootstrap, |
| 257 | struct xt_table_info *newinfo); |
| 258 | extern void *xt_unregister_table(struct xt_table *table); |
| 259 | |
| 260 | extern struct xt_table_info *xt_replace_table(struct xt_table *table, |
| 261 | unsigned int num_counters, |
| 262 | struct xt_table_info *newinfo, |
| 263 | int *error); |
| 264 | |
| 265 | extern struct xt_match *xt_find_match(u8 af, const char *name, u8 revision); |
| 266 | extern struct xt_target *xt_find_target(u8 af, const char *name, u8 revision); |
| 267 | extern struct xt_match *xt_request_find_match(u8 af, const char *name, |
| 268 | u8 revision); |
| 269 | extern struct xt_target *xt_request_find_target(u8 af, const char *name, |
| 270 | u8 revision); |
| 271 | extern int xt_find_revision(u8 af, const char *name, u8 revision, |
| 272 | int target, int *err); |
| 273 | |
| 274 | extern struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af, |
| 275 | const char *name); |
| 276 | extern void xt_table_unlock(struct xt_table *t); |
| 277 | |
| 278 | extern int xt_proto_init(struct net *net, u_int8_t af); |
| 279 | extern void xt_proto_fini(struct net *net, u_int8_t af); |
| 280 | |
| 281 | extern struct xt_table_info *xt_alloc_table_info(unsigned int size); |
| 282 | extern void xt_free_table_info(struct xt_table_info *info); |
| 283 | |
| 284 | /** |
| 285 | * xt_recseq - recursive seqcount for netfilter use |
| 286 | * |
| 287 | * Packet processing changes the seqcount only if no recursion happened |
| 288 | * get_counters() can use read_seqcount_begin()/read_seqcount_retry(), |
| 289 | * because we use the normal seqcount convention : |
| 290 | * Low order bit set to 1 if a writer is active. |
| 291 | */ |
| 292 | DECLARE_PER_CPU(seqcount_t, xt_recseq); |
| 293 | |
| 294 | /** |
| 295 | * xt_write_recseq_begin - start of a write section |
| 296 | * |
| 297 | * Begin packet processing : all readers must wait the end |
| 298 | * 1) Must be called with preemption disabled |
| 299 | * 2) softirqs must be disabled too (or we should use this_cpu_add()) |
| 300 | * Returns : |
| 301 | * 1 if no recursion on this cpu |
| 302 | * 0 if recursion detected |
| 303 | */ |
| 304 | static inline unsigned int xt_write_recseq_begin(void) |
| 305 | { |
| 306 | unsigned int addend; |
| 307 | |
| 308 | /* |
| 309 | * Low order bit of sequence is set if we already |
| 310 | * called xt_write_recseq_begin(). |
| 311 | */ |
| 312 | addend = (__this_cpu_read(xt_recseq.sequence) + 1) & 1; |
| 313 | |
| 314 | /* |
| 315 | * This is kind of a write_seqcount_begin(), but addend is 0 or 1 |
| 316 | * We dont check addend value to avoid a test and conditional jump, |
| 317 | * since addend is most likely 1 |
| 318 | */ |
| 319 | __this_cpu_add(xt_recseq.sequence, addend); |
| 320 | smp_wmb(); |
| 321 | |
| 322 | return addend; |
| 323 | } |
| 324 | |
| 325 | /** |
| 326 | * xt_write_recseq_end - end of a write section |
| 327 | * @addend: return value from previous xt_write_recseq_begin() |
| 328 | * |
| 329 | * End packet processing : all readers can proceed |
| 330 | * 1) Must be called with preemption disabled |
| 331 | * 2) softirqs must be disabled too (or we should use this_cpu_add()) |
| 332 | */ |
| 333 | static inline void xt_write_recseq_end(unsigned int addend) |
| 334 | { |
| 335 | /* this is kind of a write_seqcount_end(), but addend is 0 or 1 */ |
| 336 | smp_wmb(); |
| 337 | __this_cpu_add(xt_recseq.sequence, addend); |
| 338 | } |
| 339 | |
| 340 | /* |
| 341 | * This helper is performance critical and must be inlined |
| 342 | */ |
| 343 | static inline unsigned long ifname_compare_aligned(const char *_a, |
| 344 | const char *_b, |
| 345 | const char *_mask) |
| 346 | { |
| 347 | const unsigned long *a = (const unsigned long *)_a; |
| 348 | const unsigned long *b = (const unsigned long *)_b; |
| 349 | const unsigned long *mask = (const unsigned long *)_mask; |
| 350 | unsigned long ret; |
| 351 | |
| 352 | ret = (a[0] ^ b[0]) & mask[0]; |
| 353 | if (IFNAMSIZ > sizeof(unsigned long)) |
| 354 | ret |= (a[1] ^ b[1]) & mask[1]; |
| 355 | if (IFNAMSIZ > 2 * sizeof(unsigned long)) |
| 356 | ret |= (a[2] ^ b[2]) & mask[2]; |
| 357 | if (IFNAMSIZ > 3 * sizeof(unsigned long)) |
| 358 | ret |= (a[3] ^ b[3]) & mask[3]; |
| 359 | BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long)); |
| 360 | return ret; |
| 361 | } |
| 362 | |
| 363 | extern struct nf_hook_ops *xt_hook_link(const struct xt_table *, nf_hookfn *); |
| 364 | extern void xt_hook_unlink(const struct xt_table *, struct nf_hook_ops *); |
| 365 | |
| 366 | #ifdef CONFIG_COMPAT |
| 367 | #include <net/compat.h> |
| 368 | |
| 369 | struct compat_xt_entry_match { |
| 370 | union { |
| 371 | struct { |
| 372 | u_int16_t match_size; |
| 373 | char name[XT_FUNCTION_MAXNAMELEN - 1]; |
| 374 | u_int8_t revision; |
| 375 | } user; |
| 376 | struct { |
| 377 | u_int16_t match_size; |
| 378 | compat_uptr_t match; |
| 379 | } kernel; |
| 380 | u_int16_t match_size; |
| 381 | } u; |
| 382 | unsigned char data[0]; |
| 383 | }; |
| 384 | |
| 385 | struct compat_xt_entry_target { |
| 386 | union { |
| 387 | struct { |
| 388 | u_int16_t target_size; |
| 389 | char name[XT_FUNCTION_MAXNAMELEN - 1]; |
| 390 | u_int8_t revision; |
| 391 | } user; |
| 392 | struct { |
| 393 | u_int16_t target_size; |
| 394 | compat_uptr_t target; |
| 395 | } kernel; |
| 396 | u_int16_t target_size; |
| 397 | } u; |
| 398 | unsigned char data[0]; |
| 399 | }; |
| 400 | |
| 401 | /* FIXME: this works only on 32 bit tasks |
| 402 | * need to change whole approach in order to calculate align as function of |
| 403 | * current task alignment */ |
| 404 | |
| 405 | struct compat_xt_counters { |
| 406 | compat_u64 pcnt, bcnt; /* Packet and byte counters */ |
| 407 | }; |
| 408 | |
| 409 | struct compat_xt_counters_info { |
| 410 | char name[XT_TABLE_MAXNAMELEN]; |
| 411 | compat_uint_t num_counters; |
| 412 | struct compat_xt_counters counters[0]; |
| 413 | }; |
| 414 | |
| 415 | struct _compat_xt_align { |
| 416 | __u8 u8; |
| 417 | __u16 u16; |
| 418 | __u32 u32; |
| 419 | compat_u64 u64; |
| 420 | }; |
| 421 | |
| 422 | #define COMPAT_XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _compat_xt_align)) |
| 423 | |
| 424 | extern void xt_compat_lock(u_int8_t af); |
| 425 | extern void xt_compat_unlock(u_int8_t af); |
| 426 | |
| 427 | extern int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta); |
| 428 | extern void xt_compat_flush_offsets(u_int8_t af); |
| 429 | extern void xt_compat_init_offsets(u_int8_t af, unsigned int number); |
| 430 | extern int xt_compat_calc_jump(u_int8_t af, unsigned int offset); |
| 431 | |
| 432 | extern int xt_compat_match_offset(const struct xt_match *match); |
| 433 | extern void xt_compat_match_from_user(struct xt_entry_match *m, |
| 434 | void **dstptr, unsigned int *size); |
| 435 | extern int xt_compat_match_to_user(const struct xt_entry_match *m, |
| 436 | void __user **dstptr, unsigned int *size); |
| 437 | |
| 438 | extern int xt_compat_target_offset(const struct xt_target *target); |
| 439 | extern void xt_compat_target_from_user(struct xt_entry_target *t, |
| 440 | void **dstptr, unsigned int *size); |
| 441 | extern int xt_compat_target_to_user(const struct xt_entry_target *t, |
| 442 | void __user **dstptr, unsigned int *size); |
| 443 | int xt_compat_check_entry_offsets(const void *base, const char *elems, |
| 444 | unsigned int target_offset, |
| 445 | unsigned int next_offset); |
| 446 | |
| 447 | #endif /* CONFIG_COMPAT */ |
| 448 | #endif /* _X_TABLES_H */ |