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 #include <linux/netfilter/x_tables.h>
  29
  30 #define IP6T_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
  31 #define IP6T_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
  32
  33 #define ip6t_match xt_match
  34 #define ip6t_target xt_target
  35 #define ip6t_table xt_table
  36 #define ip6t_get_revision xt_get_revision
  37
  38 /* Yes, Virginia, you have to zero the padding. */
  39 struct ip6t_ip6 {
  40         /* Source and destination IP6 addr */
  41         struct in6_addr src, dst;
  42         /* Mask for src and dest IP6 addr */
  43         struct in6_addr smsk, dmsk;
  44         char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
  45         unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
  46
  47         /* ARGH, HopByHop uses 0, so can't do 0 = ANY,
  48            instead IP6T_F_NOPROTO must be set */
  49         u_int16_t proto;
  50         /* TOS to match iff flags & IP6T_F_TOS */
  51         u_int8_t tos;
  52
  53         /* Flags word */
  54         u_int8_t flags;
  55         /* Inverse flags */
  56         u_int8_t invflags;
  57 };
  58
  59 #define ip6t_entry_match xt_entry_match
  60 #define ip6t_entry_target xt_entry_target
  61 #define ip6t_standard_target xt_standard_target
  62
  63 #define ip6t_counters   xt_counters
  64
  65 /* Values for "flag" field in struct ip6t_ip6 (general ip6 structure). */
  66 #define IP6T_F_PROTO            0x01    /* Set if rule cares about upper
  67                                            protocols */
  68 #define IP6T_F_TOS              0x02    /* Match the TOS. */
  69 #define IP6T_F_GOTO             0x04    /* Set if jump is a goto */
  70 #define IP6T_F_MASK             0x07    /* All possible flag bits mask. */
  71
  72 /* Values for "inv" field in struct ip6t_ip6. */
  73 #define IP6T_INV_VIA_IN         0x01    /* Invert the sense of IN IFACE. */
  74 #define IP6T_INV_VIA_OUT                0x02    /* Invert the sense of OUT IFACE */
  75 #define IP6T_INV_TOS            0x04    /* Invert the sense of TOS. */
  76 #define IP6T_INV_SRCIP          0x08    /* Invert the sense of SRC IP. */
  77 #define IP6T_INV_DSTIP          0x10    /* Invert the sense of DST OP. */
  78 #define IP6T_INV_FRAG           0x20    /* Invert the sense of FRAG. */
  79 #define IP6T_INV_PROTO          XT_INV_PROTO
  80 #define IP6T_INV_MASK           0x7F    /* All possible flag bits mask. */
  81
  82 /* This structure defines each of the firewall rules.  Consists of 3
  83    parts which are 1) general IP header stuff 2) match specific
  84    stuff 3) the target to perform if the rule matches */
  85 struct ip6t_entry
  86 {
  87         struct ip6t_ip6 ipv6;
  88
  89         /* Mark with fields that we care about. */
  90         unsigned int nfcache;
  91
  92         /* Size of ipt_entry + matches */
  93         u_int16_t target_offset;
  94         /* Size of ipt_entry + matches + target */
  95         u_int16_t next_offset;
  96
  97         /* Back pointer */
  98         unsigned int comefrom;
  99
 100         /* Packet and byte counters. */
 101         struct xt_counters counters;
 102
 103         /* The matches (if any), then the target. */
 104         unsigned char elems[0];
 105 };
 106
 107 /* Standard entry */
 108 struct ip6t_standard
 109 {
 110         struct ip6t_entry entry;
 111         struct ip6t_standard_target target;
 112 };
 113
 114 struct ip6t_error_target
 115 {
 116         struct ip6t_entry_target target;
 117         char errorname[IP6T_FUNCTION_MAXNAMELEN];
 118 };
 119
 120 struct ip6t_error
 121 {
 122         struct ip6t_entry entry;
 123         struct ip6t_error_target target;
 124 };
 125
 126 #define IP6T_ENTRY_INIT(__size)                                                \
 127 {                                                                              \
 128         .target_offset  = sizeof(struct ip6t_entry),                           \
 129         .next_offset    = (__size),                                            \
 130 }
 131
 132 #define IP6T_STANDARD_INIT(__verdict)                                          \
 133 {                                                                              \
 134         .entry          = IP6T_ENTRY_INIT(sizeof(struct ip6t_standard)),       \
 135         .target         = XT_TARGET_INIT(IP6T_STANDARD_TARGET,                 \
 136                                          sizeof(struct ip6t_standard_target)), \
 137         .target.verdict = -(__verdict) - 1,                                    \
 138 }
 139
 140 #define IP6T_ERROR_INIT                                                        \
 141 {                                                                              \
 142         .entry          = IP6T_ENTRY_INIT(sizeof(struct ip6t_error)),          \
 143         .target         = XT_TARGET_INIT(IP6T_ERROR_TARGET,                    \
 144                                          sizeof(struct ip6t_error_target)),    \
 145         .target.errorname = "ERROR",                                           \
 146 }
 147
 148 /*
 149  * New IP firewall options for [gs]etsockopt at the RAW IP level.
 150  * Unlike BSD Linux inherits IP options so you don't have to use
 151  * a raw socket for this. Instead we check rights in the calls.
 152  *
 153  * ATTENTION: check linux/in6.h before adding new number here.
 154  */
 155 #define IP6T_BASE_CTL                   64
 156
 157 #define IP6T_SO_SET_REPLACE             (IP6T_BASE_CTL)
 158 #define IP6T_SO_SET_ADD_COUNTERS        (IP6T_BASE_CTL + 1)
 159 #define IP6T_SO_SET_MAX                 IP6T_SO_SET_ADD_COUNTERS
 160
 161 #define IP6T_SO_GET_INFO                (IP6T_BASE_CTL)
 162 #define IP6T_SO_GET_ENTRIES             (IP6T_BASE_CTL + 1)
 163 #define IP6T_SO_GET_REVISION_MATCH      (IP6T_BASE_CTL + 4)
 164 #define IP6T_SO_GET_REVISION_TARGET     (IP6T_BASE_CTL + 5)
 165 #define IP6T_SO_GET_MAX                 IP6T_SO_GET_REVISION_TARGET
 166
 167 /* CONTINUE verdict for targets */
 168 #define IP6T_CONTINUE XT_CONTINUE
 169
 170 /* For standard target */
 171 #define IP6T_RETURN XT_RETURN
 172
 173 /* TCP/UDP matching stuff */
 174 #include <linux/netfilter/xt_tcpudp.h>
 175
 176 #define ip6t_tcp xt_tcp
 177 #define ip6t_udp xt_udp
 178
 179 /* Values for "inv" field in struct ipt_tcp. */
 180 #define IP6T_TCP_INV_SRCPT      XT_TCP_INV_SRCPT
 181 #define IP6T_TCP_INV_DSTPT      XT_TCP_INV_DSTPT
 182 #define IP6T_TCP_INV_FLAGS      XT_TCP_INV_FLAGS
 183 #define IP6T_TCP_INV_OPTION     XT_TCP_INV_OPTION
 184 #define IP6T_TCP_INV_MASK       XT_TCP_INV_MASK
 185
 186 /* Values for "invflags" field in struct ipt_udp. */
 187 #define IP6T_UDP_INV_SRCPT      XT_UDP_INV_SRCPT
 188 #define IP6T_UDP_INV_DSTPT      XT_UDP_INV_DSTPT
 189 #define IP6T_UDP_INV_MASK       XT_UDP_INV_MASK
 190
 191 /* ICMP matching stuff */
 192 struct ip6t_icmp
 193 {
 194         u_int8_t type;                          /* type to match */
 195         u_int8_t code[2];                       /* range of code */
 196         u_int8_t invflags;                      /* Inverse flags */
 197 };
 198
 199 /* Values for "inv" field for struct ipt_icmp. */
 200 #define IP6T_ICMP_INV   0x01    /* Invert the sense of type/code test */
 201
 202 /* The argument to IP6T_SO_GET_INFO */
 203 struct ip6t_getinfo
 204 {
 205         /* Which table: caller fills this in. */
 206         char name[IP6T_TABLE_MAXNAMELEN];
 207
 208         /* Kernel fills these in. */
 209         /* Which hook entry points are valid: bitmask */
 210         unsigned int valid_hooks;
 211
 212         /* Hook entry points: one per netfilter hook. */
 213         unsigned int hook_entry[NF_IP6_NUMHOOKS];
 214
 215         /* Underflow points. */
 216         unsigned int underflow[NF_IP6_NUMHOOKS];
 217
 218         /* Number of entries */
 219         unsigned int num_entries;
 220
 221         /* Size of entries. */
 222         unsigned int size;
 223 };
 224
 225 /* The argument to IP6T_SO_SET_REPLACE. */
 226 struct ip6t_replace
 227 {
 228         /* Which table. */
 229         char name[IP6T_TABLE_MAXNAMELEN];
 230
 231         /* Which hook entry points are valid: bitmask.  You can't
 232            change this. */
 233         unsigned int valid_hooks;
 234
 235         /* Number of entries */
 236         unsigned int num_entries;
 237
 238         /* Total size of new entries */
 239         unsigned int size;
 240
 241         /* Hook entry points. */
 242         unsigned int hook_entry[NF_IP6_NUMHOOKS];
 243
 244         /* Underflow points. */
 245         unsigned int underflow[NF_IP6_NUMHOOKS];
 246
 247         /* Information about old entries: */
 248         /* Number of counters (must be equal to current number of entries). */
 249         unsigned int num_counters;
 250         /* The old entries' counters. */
 251         struct xt_counters __user *counters;
 252
 253         /* The entries (hang off end: not really an array). */
 254         struct ip6t_entry entries[0];
 255 };
 256
 257 /* The argument to IP6T_SO_ADD_COUNTERS. */
 258 #define ip6t_counters_info xt_counters_info
 259
 260 /* The argument to IP6T_SO_GET_ENTRIES. */
 261 struct ip6t_get_entries
 262 {
 263         /* Which table: user fills this in. */
 264         char name[IP6T_TABLE_MAXNAMELEN];
 265
 266         /* User fills this in: total entry size. */
 267         unsigned int size;
 268
 269         /* The entries. */
 270         struct ip6t_entry entrytable[0];
 271 };
 272
 273 /* Standard return verdict, or do jump. */
 274 #define IP6T_STANDARD_TARGET XT_STANDARD_TARGET
 275 /* Error verdict. */
 276 #define IP6T_ERROR_TARGET XT_ERROR_TARGET
 277
 278 /* Helper functions */
 279 static __inline__ struct ip6t_entry_target *
 280 ip6t_get_target(struct ip6t_entry *e)
 281 {
 282         return (void *)e + e->target_offset;
 283 }
 284
 285 /* fn returns 0 to continue iteration */
 286 #define IP6T_MATCH_ITERATE(e, fn, args...)      \
 287 ({                                              \
 288         unsigned int __i;                       \
 289         int __ret = 0;                          \
 290         struct ip6t_entry_match *__m;           \
 291                                                 \
 292         for (__i = sizeof(struct ip6t_entry);   \
 293              __i < (e)->target_offset;          \
 294              __i += __m->u.match_size) {        \
 295                 __m = (void *)(e) + __i;        \
 296                                                 \
 297                 __ret = fn(__m , ## args);      \
 298                 if (__ret != 0)                 \
 299                         break;                  \
 300         }                                       \
 301         __ret;                                  \
 302 })
 303
 304 /* fn returns 0 to continue iteration */
 305 #define IP6T_ENTRY_ITERATE(entries, size, fn, args...)          \
 306 ({                                                              \
 307         unsigned int __i;                                       \
 308         int __ret = 0;                                          \
 309         struct ip6t_entry *__e;                                 \
 310                                                                 \
 311         for (__i = 0; __i < (size); __i += __e->next_offset) {  \
 312                 __e = (void *)(entries) + __i;                  \
 313                                                                 \
 314                 __ret = fn(__e , ## args);                      \
 315                 if (__ret != 0)                                 \
 316                         break;                                  \
 317         }                                                       \
 318         __ret;                                                  \
 319 })
 320
 321 /*
 322  *      Main firewall chains definitions and global var's definitions.
 323  */
 324
 325 #ifdef __KERNEL__
 326
 327 #include <linux/init.h>
 328 extern void ip6t_init(void) __init;
 329
 330 extern int ip6t_register_table(struct xt_table *table,
 331                                const struct ip6t_replace *repl);
 332 extern void ip6t_unregister_table(struct xt_table *table);
 333 extern unsigned int ip6t_do_table(struct sk_buff **pskb,
 334                                   unsigned int hook,
 335                                   const struct net_device *in,
 336                                   const struct net_device *out,
 337                                   struct xt_table *table);
 338
 339 /* Check for an extension */
 340 extern int ip6t_ext_hdr(u8 nexthdr);
 341 /* find specified header and get offset to it */
 342 extern int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 343                          int target, unsigned short *fragoff);
 344
 345 extern int ip6_masked_addrcmp(const struct in6_addr *addr1,
 346                               const struct in6_addr *mask,
 347                               const struct in6_addr *addr2);
 348
 349 #define IP6T_ALIGN(s) (((s) + (__alignof__(struct ip6t_entry)-1)) & ~(__alignof__(struct ip6t_entry)-1))
 350
 351 #endif /*__KERNEL__*/
 352 #endif /* _IP6_TABLES_H */