include/linux/netfilter_ipv6/ip6_tables.h

   1 /*
   2  * 25-Jul-1998 Major changes to allow for ip chain table
   3  *
   4  * 3-Jan-2000 Named tables to allow packet selection for different uses.
   5  */
   6
   7 /*
   8  *      Format of an IP6 firewall descriptor
   9  *
  10  *      src, dst, src_mask, dst_mask are always stored in network byte order.
  11  *      flags are stored in host byte order (of course).
  12  *      Port numbers are stored in HOST byte order.
  13  */
  14
  15 #ifndef _IP6_TABLES_H
  16 #define _IP6_TABLES_H
  17
  18 #ifdef __KERNEL__
  19 #include <linux/if.h>
  20 #include <linux/types.h>
  21 #include <linux/in6.h>
  22 #include <linux/ipv6.h>
  23 #include <linux/skbuff.h>
  24 #endif
  25 #include <linux/compiler.h>
  26 #include <linux/netfilter_ipv6.h>
  27
  28 #define IP6T_FUNCTION_MAXNAMELEN 30
  29 #define IP6T_TABLE_MAXNAMELEN 32
  30
  31 /* Yes, Virginia, you have to zero the padding. */
  32 struct ip6t_ip6 {
  33         /* Source and destination IP6 addr */
  34         struct in6_addr src, dst;
  35         /* Mask for src and dest IP6 addr */
  36         struct in6_addr smsk, dmsk;
  37         char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
  38         unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
  39
  40         /* ARGH, HopByHop uses 0, so can't do 0 = ANY,
  41            instead IP6T_F_NOPROTO must be set */
  42         u_int16_t proto;
  43         /* TOS to match iff flags & IP6T_F_TOS */
  44         u_int8_t tos;
  45
  46         /* Flags word */
  47         u_int8_t flags;
  48         /* Inverse flags */
  49         u_int8_t invflags;
  50 };
  51
  52 /* FIXME: If alignment in kernel different from userspace? --RR */
  53 struct ip6t_entry_match
  54 {
  55         union {
  56                 struct {
  57                         u_int16_t match_size;
  58
  59                         /* Used by userspace */
  60                         char name[IP6T_FUNCTION_MAXNAMELEN-1];
  61                         u_int8_t revision;
  62                 } user;
  63                 struct {
  64                         u_int16_t match_size;
  65
  66                         /* Used inside the kernel */
  67                         struct ip6t_match *match;
  68                 } kernel;
  69
  70                 /* Total length */
  71                 u_int16_t match_size;
  72         } u;
  73
  74         unsigned char data[0];
  75 };
  76
  77 struct ip6t_entry_target
  78 {
  79         union {
  80                 struct {
  81                         u_int16_t target_size;
  82
  83                         /* Used by userspace */
  84                         char name[IP6T_FUNCTION_MAXNAMELEN-1];
  85                         u_int8_t revision;
  86                 } user;
  87                 struct {
  88                         u_int16_t target_size;
  89
  90                         /* Used inside the kernel */
  91                         struct ip6t_target *target;
  92                 } kernel;
  93
  94                 /* Total length */
  95                 u_int16_t target_size;
  96         } u;
  97
  98         unsigned char data[0];
  99 };
 100
 101 struct ip6t_standard_target
 102 {
 103         struct ip6t_entry_target target;
 104         int verdict;
 105 };
 106
 107 struct ip6t_counters
 108 {
 109         u_int64_t pcnt, bcnt;                   /* Packet and byte counters */
 110 };
 111
 112 /* Values for "flag" field in struct ip6t_ip6 (general ip6 structure). */
 113 #define IP6T_F_PROTO            0x01    /* Set if rule cares about upper
 114                                            protocols */
 115 #define IP6T_F_TOS              0x02    /* Match the TOS. */
 116 #define IP6T_F_GOTO             0x04    /* Set if jump is a goto */
 117 #define IP6T_F_MASK             0x07    /* All possible flag bits mask. */
 118
 119 /* Values for "inv" field in struct ip6t_ip6. */
 120 #define IP6T_INV_VIA_IN         0x01    /* Invert the sense of IN IFACE. */
 121 #define IP6T_INV_VIA_OUT                0x02    /* Invert the sense of OUT IFACE */
 122 #define IP6T_INV_TOS            0x04    /* Invert the sense of TOS. */
 123 #define IP6T_INV_SRCIP          0x08    /* Invert the sense of SRC IP. */
 124 #define IP6T_INV_DSTIP          0x10    /* Invert the sense of DST OP. */
 125 #define IP6T_INV_FRAG           0x20    /* Invert the sense of FRAG. */
 126 #define IP6T_INV_PROTO          0x40    /* Invert the sense of PROTO. */
 127 #define IP6T_INV_MASK           0x7F    /* All possible flag bits mask. */
 128
 129 /* This structure defines each of the firewall rules.  Consists of 3
 130    parts which are 1) general IP header stuff 2) match specific
 131    stuff 3) the target to perform if the rule matches */
 132 struct ip6t_entry
 133 {
 134         struct ip6t_ip6 ipv6;
 135
 136         /* Mark with fields that we care about. */
 137         unsigned int nfcache;
 138
 139         /* Size of ipt_entry + matches */
 140         u_int16_t target_offset;
 141         /* Size of ipt_entry + matches + target */
 142         u_int16_t next_offset;
 143
 144         /* Back pointer */
 145         unsigned int comefrom;
 146
 147         /* Packet and byte counters. */
 148         struct ip6t_counters counters;
 149
 150         /* The matches (if any), then the target. */
 151         unsigned char elems[0];
 152 };
 153
 154 /*
 155  * New IP firewall options for [gs]etsockopt at the RAW IP level.
 156  * Unlike BSD Linux inherits IP options so you don't have to use
 157  * a raw socket for this. Instead we check rights in the calls. */
 158 #define IP6T_BASE_CTL                   64      /* base for firewall socket options */
 159
 160 #define IP6T_SO_SET_REPLACE             (IP6T_BASE_CTL)
 161 #define IP6T_SO_SET_ADD_COUNTERS        (IP6T_BASE_CTL + 1)
 162 #define IP6T_SO_SET_MAX                 IP6T_SO_SET_ADD_COUNTERS
 163
 164 #define IP6T_SO_GET_INFO                (IP6T_BASE_CTL)
 165 #define IP6T_SO_GET_ENTRIES             (IP6T_BASE_CTL + 1)
 166 #define IP6T_SO_GET_REVISION_MATCH      (IP6T_BASE_CTL + 2)
 167 #define IP6T_SO_GET_REVISION_TARGET     (IP6T_BASE_CTL + 3)
 168 #define IP6T_SO_GET_MAX                 IP6T_SO_GET_REVISION_TARGET
 169
 170 /* CONTINUE verdict for targets */
 171 #define IP6T_CONTINUE 0xFFFFFFFF
 172
 173 /* For standard target */
 174 #define IP6T_RETURN (-NF_REPEAT - 1)
 175
 176 /* TCP matching stuff */
 177 struct ip6t_tcp
 178 {
 179         u_int16_t spts[2];                      /* Source port range. */
 180         u_int16_t dpts[2];                      /* Destination port range. */
 181         u_int8_t option;                        /* TCP Option iff non-zero*/
 182         u_int8_t flg_mask;                      /* TCP flags mask byte */
 183         u_int8_t flg_cmp;                       /* TCP flags compare byte */
 184         u_int8_t invflags;                      /* Inverse flags */
 185 };
 186
 187 /* Values for "inv" field in struct ipt_tcp. */
 188 #define IP6T_TCP_INV_SRCPT      0x01    /* Invert the sense of source ports. */
 189 #define IP6T_TCP_INV_DSTPT      0x02    /* Invert the sense of dest ports. */
 190 #define IP6T_TCP_INV_FLAGS      0x04    /* Invert the sense of TCP flags. */
 191 #define IP6T_TCP_INV_OPTION     0x08    /* Invert the sense of option test. */
 192 #define IP6T_TCP_INV_MASK       0x0F    /* All possible flags. */
 193
 194 /* UDP matching stuff */
 195 struct ip6t_udp
 196 {
 197         u_int16_t spts[2];                      /* Source port range. */
 198         u_int16_t dpts[2];                      /* Destination port range. */
 199         u_int8_t invflags;                      /* Inverse flags */
 200 };
 201
 202 /* Values for "invflags" field in struct ipt_udp. */
 203 #define IP6T_UDP_INV_SRCPT      0x01    /* Invert the sense of source ports. */
 204 #define IP6T_UDP_INV_DSTPT      0x02    /* Invert the sense of dest ports. */
 205 #define IP6T_UDP_INV_MASK       0x03    /* All possible flags. */
 206
 207 /* ICMP matching stuff */
 208 struct ip6t_icmp
 209 {
 210         u_int8_t type;                          /* type to match */
 211         u_int8_t code[2];                       /* range of code */
 212         u_int8_t invflags;                      /* Inverse flags */
 213 };
 214
 215 /* Values for "inv" field for struct ipt_icmp. */
 216 #define IP6T_ICMP_INV   0x01    /* Invert the sense of type/code test */
 217
 218 /* The argument to IP6T_SO_GET_INFO */
 219 struct ip6t_getinfo
 220 {
 221         /* Which table: caller fills this in. */
 222         char name[IP6T_TABLE_MAXNAMELEN];
 223
 224         /* Kernel fills these in. */
 225         /* Which hook entry points are valid: bitmask */
 226         unsigned int valid_hooks;
 227
 228         /* Hook entry points: one per netfilter hook. */
 229         unsigned int hook_entry[NF_IP6_NUMHOOKS];
 230
 231         /* Underflow points. */
 232         unsigned int underflow[NF_IP6_NUMHOOKS];
 233
 234         /* Number of entries */
 235         unsigned int num_entries;
 236
 237         /* Size of entries. */
 238         unsigned int size;
 239 };
 240
 241 /* The argument to IP6T_SO_SET_REPLACE. */
 242 struct ip6t_replace
 243 {
 244         /* Which table. */
 245         char name[IP6T_TABLE_MAXNAMELEN];
 246
 247         /* Which hook entry points are valid: bitmask.  You can't
 248            change this. */
 249         unsigned int valid_hooks;
 250
 251         /* Number of entries */
 252         unsigned int num_entries;
 253
 254         /* Total size of new entries */
 255         unsigned int size;
 256
 257         /* Hook entry points. */
 258         unsigned int hook_entry[NF_IP6_NUMHOOKS];
 259
 260         /* Underflow points. */
 261         unsigned int underflow[NF_IP6_NUMHOOKS];
 262
 263         /* Information about old entries: */
 264         /* Number of counters (must be equal to current number of entries). */
 265         unsigned int num_counters;
 266         /* The old entries' counters. */
 267         struct ip6t_counters __user *counters;
 268
 269         /* The entries (hang off end: not really an array). */
 270         struct ip6t_entry entries[0];
 271 };
 272
 273 /* The argument to IP6T_SO_ADD_COUNTERS. */
 274 struct ip6t_counters_info
 275 {
 276         /* Which table. */
 277         char name[IP6T_TABLE_MAXNAMELEN];
 278
 279         unsigned int num_counters;
 280
 281         /* The counters (actually `number' of these). */
 282         struct ip6t_counters counters[0];
 283 };
 284
 285 /* The argument to IP6T_SO_GET_ENTRIES. */
 286 struct ip6t_get_entries
 287 {
 288         /* Which table: user fills this in. */
 289         char name[IP6T_TABLE_MAXNAMELEN];
 290
 291         /* User fills this in: total entry size. */
 292         unsigned int size;
 293
 294         /* The entries. */
 295         struct ip6t_entry entrytable[0];
 296 };
 297
 298 /* The argument to IP6T_SO_GET_REVISION_*.  Returns highest revision
 299  * kernel supports, if >= revision. */
 300 struct ip6t_get_revision
 301 {
 302         char name[IP6T_FUNCTION_MAXNAMELEN-1];
 303
 304         u_int8_t revision;
 305 };
 306
 307 /* Standard return verdict, or do jump. */
 308 #define IP6T_STANDARD_TARGET ""
 309 /* Error verdict. */
 310 #define IP6T_ERROR_TARGET "ERROR"
 311
 312 /* Helper functions */
 313 static __inline__ struct ip6t_entry_target *
 314 ip6t_get_target(struct ip6t_entry *e)
 315 {
 316         return (void *)e + e->target_offset;
 317 }
 318
 319 /* fn returns 0 to continue iteration */
 320 #define IP6T_MATCH_ITERATE(e, fn, args...)      \
 321 ({                                              \
 322         unsigned int __i;                       \
 323         int __ret = 0;                          \
 324         struct ip6t_entry_match *__m;           \
 325                                                 \
 326         for (__i = sizeof(struct ip6t_entry);   \
 327              __i < (e)->target_offset;          \
 328              __i += __m->u.match_size) {        \
 329                 __m = (void *)(e) + __i;        \
 330                                                 \
 331                 __ret = fn(__m , ## args);      \
 332                 if (__ret != 0)                 \
 333                         break;                  \
 334         }                                       \
 335         __ret;                                  \
 336 })
 337
 338 /* fn returns 0 to continue iteration */
 339 #define IP6T_ENTRY_ITERATE(entries, size, fn, args...)          \
 340 ({                                                              \
 341         unsigned int __i;                                       \
 342         int __ret = 0;                                          \
 343         struct ip6t_entry *__e;                                 \
 344                                                                 \
 345         for (__i = 0; __i < (size); __i += __e->next_offset) {  \
 346                 __e = (void *)(entries) + __i;                  \
 347                                                                 \
 348                 __ret = fn(__e , ## args);                      \
 349                 if (__ret != 0)                                 \
 350                         break;                                  \
 351         }                                                       \
 352         __ret;                                                  \
 353 })
 354
 355 /*
 356  *      Main firewall chains definitions and global var's definitions.
 357  */
 358
 359 #ifdef __KERNEL__
 360
 361 #include <linux/init.h>
 362 extern void ip6t_init(void) __init;
 363
 364 struct ip6t_match
 365 {
 366         struct list_head list;
 367
 368         const char name[IP6T_FUNCTION_MAXNAMELEN-1];
 369
 370         u_int8_t revision;
 371
 372         /* Return true or false: return FALSE and set *hotdrop = 1 to
 373            force immediate packet drop. */
 374         /* Arguments changed since 2.6.9, as this must now handle
 375            non-linear skb, using skb_header_pointer and
 376            skb_ip_make_writable. */
 377         int (*match)(const struct sk_buff *skb,
 378                      const struct net_device *in,
 379                      const struct net_device *out,
 380                      const void *matchinfo,
 381                      int offset,
 382                      unsigned int protoff,
 383                      int *hotdrop);
 384
 385         /* Called when user tries to insert an entry of this type. */
 386         /* Should return true or false. */
 387         int (*checkentry)(const char *tablename,
 388                           const struct ip6t_ip6 *ip,
 389                           void *matchinfo,
 390                           unsigned int matchinfosize,
 391                           unsigned int hook_mask);
 392
 393         /* Called when entry of this type deleted. */
 394         void (*destroy)(void *matchinfo, unsigned int matchinfosize);
 395
 396         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 397         struct module *me;
 398 };
 399
 400 /* Registration hooks for targets. */
 401 struct ip6t_target
 402 {
 403         struct list_head list;
 404
 405         const char name[IP6T_FUNCTION_MAXNAMELEN-1];
 406
 407         u_int8_t revision;
 408
 409         /* Returns verdict. Argument order changed since 2.6.9, as this
 410            must now handle non-linear skbs, using skb_copy_bits and
 411            skb_ip_make_writable. */
 412         unsigned int (*target)(struct sk_buff **pskb,
 413                                const struct net_device *in,
 414                                const struct net_device *out,
 415                                unsigned int hooknum,
 416                                const void *targinfo,
 417                                void *userdata);
 418
 419         /* Called when user tries to insert an entry of this type:
 420            hook_mask is a bitmask of hooks from which it can be
 421            called. */
 422         /* Should return true or false. */
 423         int (*checkentry)(const char *tablename,
 424                           const struct ip6t_entry *e,
 425                           void *targinfo,
 426                           unsigned int targinfosize,
 427                           unsigned int hook_mask);
 428
 429         /* Called when entry of this type deleted. */
 430         void (*destroy)(void *targinfo, unsigned int targinfosize);
 431
 432         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 433         struct module *me;
 434 };
 435
 436 extern int ip6t_register_target(struct ip6t_target *target);
 437 extern void ip6t_unregister_target(struct ip6t_target *target);
 438
 439 extern int ip6t_register_match(struct ip6t_match *match);
 440 extern void ip6t_unregister_match(struct ip6t_match *match);
 441
 442 /* Furniture shopping... */
 443 struct ip6t_table
 444 {
 445         struct list_head list;
 446
 447         /* A unique name... */
 448         char name[IP6T_TABLE_MAXNAMELEN];
 449
 450         /* What hooks you will enter on */
 451         unsigned int valid_hooks;
 452
 453         /* Lock for the curtain */
 454         rwlock_t lock;
 455
 456         /* Man behind the curtain... */
 457         struct ip6t_table_info *private;
 458
 459         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 460         struct module *me;
 461 };
 462
 463 extern int ip6t_register_table(struct ip6t_table *table,
 464                                const struct ip6t_replace *repl);
 465 extern void ip6t_unregister_table(struct ip6t_table *table);
 466 extern unsigned int ip6t_do_table(struct sk_buff **pskb,
 467                                   unsigned int hook,
 468                                   const struct net_device *in,
 469                                   const struct net_device *out,
 470                                   struct ip6t_table *table,
 471                                   void *userdata);
 472
 473 /* Check for an extension */
 474 extern int ip6t_ext_hdr(u8 nexthdr);
 475 /* find specified header and get offset to it */
 476 extern int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 477                          int target, unsigned short *fragoff);
 478
 479 #define IP6T_ALIGN(s) (((s) + (__alignof__(struct ip6t_entry)-1)) & ~(__alignof__(struct ip6t_entry)-1))
 480
 481 #endif /*__KERNEL__*/
 482 #endif /* _IP6_TABLES_H */