include/linux/netfilter/x_tables.h

   1 #ifndef _X_TABLES_H
   2 #define _X_TABLES_H
   3
   4 #define XT_FUNCTION_MAXNAMELEN 30
   5 #define XT_TABLE_MAXNAMELEN 32
   6
   7 struct xt_entry_match
   8 {
   9         union {
  10                 struct {
  11                         u_int16_t match_size;
  12
  13                         /* Used by userspace */
  14                         char name[XT_FUNCTION_MAXNAMELEN-1];
  15
  16                         u_int8_t revision;
  17                 } user;
  18                 struct {
  19                         u_int16_t match_size;
  20
  21                         /* Used inside the kernel */
  22                         struct xt_match *match;
  23                 } kernel;
  24
  25                 /* Total length */
  26                 u_int16_t match_size;
  27         } u;
  28
  29         unsigned char data[0];
  30 };
  31
  32 struct xt_entry_target
  33 {
  34         union {
  35                 struct {
  36                         u_int16_t target_size;
  37
  38                         /* Used by userspace */
  39                         char name[XT_FUNCTION_MAXNAMELEN-1];
  40
  41                         u_int8_t revision;
  42                 } user;
  43                 struct {
  44                         u_int16_t target_size;
  45
  46                         /* Used inside the kernel */
  47                         struct xt_target *target;
  48                 } kernel;
  49
  50                 /* Total length */
  51                 u_int16_t target_size;
  52         } u;
  53
  54         unsigned char data[0];
  55 };
  56
  57 struct xt_standard_target
  58 {
  59         struct xt_entry_target target;
  60         int verdict;
  61 };
  62
  63 /* The argument to IPT_SO_GET_REVISION_*.  Returns highest revision
  64  * kernel supports, if >= revision. */
  65 struct xt_get_revision
  66 {
  67         char name[XT_FUNCTION_MAXNAMELEN-1];
  68
  69         u_int8_t revision;
  70 };
  71
  72 /* CONTINUE verdict for targets */
  73 #define XT_CONTINUE 0xFFFFFFFF
  74
  75 /* For standard target */
  76 #define XT_RETURN (-NF_REPEAT - 1)
  77
  78 /* this is a dummy structure to find out the alignment requirement for a struct
  79  * containing all the fundamental data types that are used in ipt_entry,
  80  * ip6t_entry and arpt_entry.  This sucks, and it is a hack.  It will be my
  81  * personal pleasure to remove it -HW
  82  */
  83 struct _xt_align
  84 {
  85         u_int8_t u8;
  86         u_int16_t u16;
  87         u_int32_t u32;
  88         u_int64_t u64;
  89 };
  90
  91 #define XT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1))  \
  92                         & ~(__alignof__(struct _xt_align)-1))
  93
  94 /* Standard return verdict, or do jump. */
  95 #define XT_STANDARD_TARGET ""
  96 /* Error verdict. */
  97 #define XT_ERROR_TARGET "ERROR"
  98
  99 #define SET_COUNTER(c,b,p) do { (c).bcnt = (b); (c).pcnt = (p); } while(0)
 100 #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
 101
 102 struct xt_counters
 103 {
 104         u_int64_t pcnt, bcnt;                   /* Packet and byte counters */
 105 };
 106
 107 /* The argument to IPT_SO_ADD_COUNTERS. */
 108 struct xt_counters_info
 109 {
 110         /* Which table. */
 111         char name[XT_TABLE_MAXNAMELEN];
 112
 113         unsigned int num_counters;
 114
 115         /* The counters (actually `number' of these). */
 116         struct xt_counters counters[0];
 117 };
 118
 119 #define XT_INV_PROTO            0x40    /* Invert the sense of PROTO. */
 120
 121 #ifdef __KERNEL__
 122
 123 #include <linux/netdevice.h>
 124
 125 struct xt_match
 126 {
 127         struct list_head list;
 128
 129         const char name[XT_FUNCTION_MAXNAMELEN-1];
 130
 131         /* Return true or false: return FALSE and set *hotdrop = 1 to
 132            force immediate packet drop. */
 133         /* Arguments changed since 2.6.9, as this must now handle
 134            non-linear skb, using skb_header_pointer and
 135            skb_ip_make_writable. */
 136         int (*match)(const struct sk_buff *skb,
 137                      const struct net_device *in,
 138                      const struct net_device *out,
 139                      const struct xt_match *match,
 140                      const void *matchinfo,
 141                      int offset,
 142                      unsigned int protoff,
 143                      int *hotdrop);
 144
 145         /* Called when user tries to insert an entry of this type. */
 146         /* Should return true or false. */
 147         int (*checkentry)(const char *tablename,
 148                           const void *ip,
 149                           const struct xt_match *match,
 150                           void *matchinfo,
 151                           unsigned int hook_mask);
 152
 153         /* Called when entry of this type deleted. */
 154         void (*destroy)(const struct xt_match *match, void *matchinfo);
 155
 156         /* Called when userspace align differs from kernel space one */
 157         void (*compat_from_user)(void *dst, void *src);
 158         int (*compat_to_user)(void __user *dst, void *src);
 159
 160         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 161         struct module *me;
 162
 163         /* Free to use by each match */
 164         unsigned long data;
 165
 166         char *table;
 167         unsigned int matchsize;
 168         unsigned int compatsize;
 169         unsigned int hooks;
 170         unsigned short proto;
 171
 172         unsigned short family;
 173         u_int8_t revision;
 174 };
 175
 176 /* Registration hooks for targets. */
 177 struct xt_target
 178 {
 179         struct list_head list;
 180
 181         const char name[XT_FUNCTION_MAXNAMELEN-1];
 182
 183         /* Returns verdict. Argument order changed since 2.6.9, as this
 184            must now handle non-linear skbs, using skb_copy_bits and
 185            skb_ip_make_writable. */
 186         unsigned int (*target)(struct sk_buff **pskb,
 187                                const struct net_device *in,
 188                                const struct net_device *out,
 189                                unsigned int hooknum,
 190                                const struct xt_target *target,
 191                                const void *targinfo);
 192
 193         /* Called when user tries to insert an entry of this type:
 194            hook_mask is a bitmask of hooks from which it can be
 195            called. */
 196         /* Should return true or false. */
 197         int (*checkentry)(const char *tablename,
 198                           const void *entry,
 199                           const struct xt_target *target,
 200                           void *targinfo,
 201                           unsigned int hook_mask);
 202
 203         /* Called when entry of this type deleted. */
 204         void (*destroy)(const struct xt_target *target, void *targinfo);
 205
 206         /* Called when userspace align differs from kernel space one */
 207         void (*compat_from_user)(void *dst, void *src);
 208         int (*compat_to_user)(void __user *dst, void *src);
 209
 210         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 211         struct module *me;
 212
 213         char *table;
 214         unsigned int targetsize;
 215         unsigned int compatsize;
 216         unsigned int hooks;
 217         unsigned short proto;
 218
 219         unsigned short family;
 220         u_int8_t revision;
 221 };
 222
 223 /* Furniture shopping... */
 224 struct xt_table
 225 {
 226         struct list_head list;
 227
 228         /* A unique name... */
 229         char name[XT_TABLE_MAXNAMELEN];
 230
 231         /* What hooks you will enter on */
 232         unsigned int valid_hooks;
 233
 234         /* Lock for the curtain */
 235         rwlock_t lock;
 236
 237         /* Man behind the curtain... */
 238         //struct ip6t_table_info *private;
 239         void *private;
 240
 241         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 242         struct module *me;
 243
 244         int af;         /* address/protocol family */
 245 };
 246
 247 #include <linux/netfilter_ipv4.h>
 248
 249 /* The table itself */
 250 struct xt_table_info
 251 {
 252         /* Size per table */
 253         unsigned int size;
 254         /* Number of entries: FIXME. --RR */
 255         unsigned int number;
 256         /* Initial number of entries. Needed for module usage count */
 257         unsigned int initial_entries;
 258
 259         /* Entry points and underflows */
 260         unsigned int hook_entry[NF_IP_NUMHOOKS];
 261         unsigned int underflow[NF_IP_NUMHOOKS];
 262
 263         /* ipt_entry tables: one per CPU */
 264         char *entries[NR_CPUS];
 265 };
 266
 267 extern int xt_register_target(struct xt_target *target);
 268 extern void xt_unregister_target(struct xt_target *target);
 269 extern int xt_register_targets(struct xt_target *target, unsigned int n);
 270 extern void xt_unregister_targets(struct xt_target *target, unsigned int n);
 271
 272 extern int xt_register_match(struct xt_match *target);
 273 extern void xt_unregister_match(struct xt_match *target);
 274 extern int xt_register_matches(struct xt_match *match, unsigned int n);
 275 extern void xt_unregister_matches(struct xt_match *match, unsigned int n);
 276
 277 extern int xt_check_match(const struct xt_match *match, unsigned short family,
 278                           unsigned int size, const char *table, unsigned int hook,
 279                           unsigned short proto, int inv_proto);
 280 extern int xt_check_target(const struct xt_target *target, unsigned short family,
 281                            unsigned int size, const char *table, unsigned int hook,
 282                            unsigned short proto, int inv_proto);
 283
 284 extern int xt_register_table(struct xt_table *table,
 285                              struct xt_table_info *bootstrap,
 286                              struct xt_table_info *newinfo);
 287 extern void *xt_unregister_table(struct xt_table *table);
 288
 289 extern struct xt_table_info *xt_replace_table(struct xt_table *table,
 290                                               unsigned int num_counters,
 291                                               struct xt_table_info *newinfo,
 292                                               int *error);
 293
 294 extern struct xt_match *xt_find_match(int af, const char *name, u8 revision);
 295 extern struct xt_target *xt_find_target(int af, const char *name, u8 revision);
 296 extern struct xt_target *xt_request_find_target(int af, const char *name,
 297                                                 u8 revision);
 298 extern int xt_find_revision(int af, const char *name, u8 revision, int target,
 299                             int *err);
 300
 301 extern struct xt_table *xt_find_table_lock(int af, const char *name);
 302 extern void xt_table_unlock(struct xt_table *t);
 303
 304 extern int xt_proto_init(int af);
 305 extern void xt_proto_fini(int af);
 306
 307 extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
 308 extern void xt_free_table_info(struct xt_table_info *info);
 309
 310 #ifdef CONFIG_COMPAT
 311 #include <net/compat.h>
 312
 313 struct compat_xt_entry_match
 314 {
 315         union {
 316                 struct {
 317                         u_int16_t match_size;
 318                         char name[XT_FUNCTION_MAXNAMELEN - 1];
 319                         u_int8_t revision;
 320                 } user;
 321                 struct {
 322                         u_int16_t match_size;
 323                         compat_uptr_t match;
 324                 } kernel;
 325                 u_int16_t match_size;
 326         } u;
 327         unsigned char data[0];
 328 };
 329
 330 struct compat_xt_entry_target
 331 {
 332         union {
 333                 struct {
 334                         u_int16_t target_size;
 335                         char name[XT_FUNCTION_MAXNAMELEN - 1];
 336                         u_int8_t revision;
 337                 } user;
 338                 struct {
 339                         u_int16_t target_size;
 340                         compat_uptr_t target;
 341                 } kernel;
 342                 u_int16_t target_size;
 343         } u;
 344         unsigned char data[0];
 345 };
 346
 347 /* FIXME: this works only on 32 bit tasks
 348  * need to change whole approach in order to calculate align as function of
 349  * current task alignment */
 350
 351 struct compat_xt_counters
 352 {
 353 #if defined(CONFIG_X86_64) || defined(CONFIG_IA64)
 354         u_int32_t cnt[4];
 355 #else
 356         u_int64_t cnt[2];
 357 #endif
 358 };
 359
 360 struct compat_xt_counters_info
 361 {
 362         char name[XT_TABLE_MAXNAMELEN];
 363         compat_uint_t num_counters;
 364         struct compat_xt_counters counters[0];
 365 };
 366
 367 #define COMPAT_XT_ALIGN(s) (((s) + (__alignof__(struct compat_xt_counters)-1)) \
 368                 & ~(__alignof__(struct compat_xt_counters)-1))
 369
 370 extern void xt_compat_lock(int af);
 371 extern void xt_compat_unlock(int af);
 372
 373 extern int xt_compat_match_offset(struct xt_match *match);
 374 extern void xt_compat_match_from_user(struct xt_entry_match *m,
 375                                       void **dstptr, int *size);
 376 extern int xt_compat_match_to_user(struct xt_entry_match *m,
 377                                    void __user **dstptr, int *size);
 378
 379 extern int xt_compat_target_offset(struct xt_target *target);
 380 extern void xt_compat_target_from_user(struct xt_entry_target *t,
 381                                        void **dstptr, int *size);
 382 extern int xt_compat_target_to_user(struct xt_entry_target *t,
 383                                     void __user **dstptr, int *size);
 384
 385 #endif /* CONFIG_COMPAT */
 386 #endif /* __KERNEL__ */
 387
 388 #endif /* _X_TABLES_H */