include/linux/netfilter_ipv4/ip_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 IP 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 _IPTABLES_H
  16 #define _IPTABLES_H
  17
  18 #ifdef __KERNEL__
  19 #include <linux/if.h>
  20 #include <linux/types.h>
  21 #include <linux/in.h>
  22 #include <linux/ip.h>
  23 #include <linux/skbuff.h>
  24 #endif
  25 #include <linux/compiler.h>
  26 #include <linux/netfilter_ipv4.h>
  27
  28 #include <linux/netfilter/x_tables.h>
  29
  30 #define IPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
  31 #define IPT_TABLE_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
  32 #define ipt_match xt_match
  33 #define ipt_target xt_target
  34 #define ipt_table xt_table
  35 #define ipt_get_revision xt_get_revision
  36
  37 /* Yes, Virginia, you have to zero the padding. */
  38 struct ipt_ip {
  39         /* Source and destination IP addr */
  40         struct in_addr src, dst;
  41         /* Mask for src and dest IP addr */
  42         struct in_addr smsk, dmsk;
  43         char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
  44         unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
  45
  46         /* Protocol, 0 = ANY */
  47         u_int16_t proto;
  48
  49         /* Flags word */
  50         u_int8_t flags;
  51         /* Inverse flags */
  52         u_int8_t invflags;
  53 };
  54
  55 #define ipt_entry_match xt_entry_match
  56 #define ipt_entry_target xt_entry_target
  57 #define ipt_standard_target xt_standard_target
  58
  59 #define ipt_counters xt_counters
  60
  61 /* Values for "flag" field in struct ipt_ip (general ip structure). */
  62 #define IPT_F_FRAG              0x01    /* Set if rule is a fragment rule */
  63 #define IPT_F_GOTO              0x02    /* Set if jump is a goto */
  64 #define IPT_F_MASK              0x03    /* All possible flag bits mask. */
  65
  66 /* Values for "inv" field in struct ipt_ip. */
  67 #define IPT_INV_VIA_IN          0x01    /* Invert the sense of IN IFACE. */
  68 #define IPT_INV_VIA_OUT         0x02    /* Invert the sense of OUT IFACE */
  69 #define IPT_INV_TOS             0x04    /* Invert the sense of TOS. */
  70 #define IPT_INV_SRCIP           0x08    /* Invert the sense of SRC IP. */
  71 #define IPT_INV_DSTIP           0x10    /* Invert the sense of DST OP. */
  72 #define IPT_INV_FRAG            0x20    /* Invert the sense of FRAG. */
  73 #define IPT_INV_PROTO           XT_INV_PROTO
  74 #define IPT_INV_MASK            0x7F    /* All possible flag bits mask. */
  75
  76 /* This structure defines each of the firewall rules.  Consists of 3
  77    parts which are 1) general IP header stuff 2) match specific
  78    stuff 3) the target to perform if the rule matches */
  79 struct ipt_entry
  80 {
  81         struct ipt_ip ip;
  82
  83         /* Mark with fields that we care about. */
  84         unsigned int nfcache;
  85
  86         /* Size of ipt_entry + matches */
  87         u_int16_t target_offset;
  88         /* Size of ipt_entry + matches + target */
  89         u_int16_t next_offset;
  90
  91         /* Back pointer */
  92         unsigned int comefrom;
  93
  94         /* Packet and byte counters. */
  95         struct xt_counters counters;
  96
  97         /* The matches (if any), then the target. */
  98         unsigned char elems[0];
  99 };
 100
 101 /*
 102  * New IP firewall options for [gs]etsockopt at the RAW IP level.
 103  * Unlike BSD Linux inherits IP options so you don't have to use a raw
 104  * socket for this. Instead we check rights in the calls. */
 105 #define IPT_BASE_CTL            XT_BASE_CTL
 106
 107 #define IPT_SO_SET_REPLACE      XT_SO_SET_REPLACE
 108 #define IPT_SO_SET_ADD_COUNTERS XT_SO_SET_ADD_COUNTERS
 109 #define IPT_SO_SET_MAX          XT_SO_SET_MAX
 110
 111 #define IPT_SO_GET_INFO                 XT_SO_GET_INFO
 112 #define IPT_SO_GET_ENTRIES              XT_SO_GET_ENTRIES
 113 #define IPT_SO_GET_REVISION_MATCH       XT_SO_GET_REVISION_MATCH
 114 #define IPT_SO_GET_REVISION_TARGET      XT_SO_GET_REVISION_TARGET
 115 #define IPT_SO_GET_MAX                  XT_SO_GET_REVISION_TARGET
 116
 117 #define IPT_CONTINUE XT_CONTINUE
 118 #define IPT_RETURN XT_RETURN
 119
 120 #include <linux/netfilter/xt_tcpudp.h>
 121 #define ipt_udp xt_udp
 122 #define ipt_tcp xt_tcp
 123
 124 #define IPT_TCP_INV_SRCPT       XT_TCP_INV_SRCPT
 125 #define IPT_TCP_INV_DSTPT       XT_TCP_INV_DSTPT
 126 #define IPT_TCP_INV_FLAGS       XT_TCP_INV_FLAGS
 127 #define IPT_TCP_INV_OPTION      XT_TCP_INV_OPTION
 128 #define IPT_TCP_INV_MASK        XT_TCP_INV_MASK
 129
 130 #define IPT_UDP_INV_SRCPT       XT_UDP_INV_SRCPT
 131 #define IPT_UDP_INV_DSTPT       XT_UDP_INV_DSTPT
 132 #define IPT_UDP_INV_MASK        XT_UDP_INV_MASK
 133
 134 /* ICMP matching stuff */
 135 struct ipt_icmp
 136 {
 137         u_int8_t type;                          /* type to match */
 138         u_int8_t code[2];                       /* range of code */
 139         u_int8_t invflags;                      /* Inverse flags */
 140 };
 141
 142 /* Values for "inv" field for struct ipt_icmp. */
 143 #define IPT_ICMP_INV    0x01    /* Invert the sense of type/code test */
 144
 145 /* The argument to IPT_SO_GET_INFO */
 146 struct ipt_getinfo
 147 {
 148         /* Which table: caller fills this in. */
 149         char name[IPT_TABLE_MAXNAMELEN];
 150
 151         /* Kernel fills these in. */
 152         /* Which hook entry points are valid: bitmask */
 153         unsigned int valid_hooks;
 154
 155         /* Hook entry points: one per netfilter hook. */
 156         unsigned int hook_entry[NF_IP_NUMHOOKS];
 157
 158         /* Underflow points. */
 159         unsigned int underflow[NF_IP_NUMHOOKS];
 160
 161         /* Number of entries */
 162         unsigned int num_entries;
 163
 164         /* Size of entries. */
 165         unsigned int size;
 166 };
 167
 168 /* The argument to IPT_SO_SET_REPLACE. */
 169 struct ipt_replace
 170 {
 171         /* Which table. */
 172         char name[IPT_TABLE_MAXNAMELEN];
 173
 174         /* Which hook entry points are valid: bitmask.  You can't
 175            change this. */
 176         unsigned int valid_hooks;
 177
 178         /* Number of entries */
 179         unsigned int num_entries;
 180
 181         /* Total size of new entries */
 182         unsigned int size;
 183
 184         /* Hook entry points. */
 185         unsigned int hook_entry[NF_IP_NUMHOOKS];
 186
 187         /* Underflow points. */
 188         unsigned int underflow[NF_IP_NUMHOOKS];
 189
 190         /* Information about old entries: */
 191         /* Number of counters (must be equal to current number of entries). */
 192         unsigned int num_counters;
 193         /* The old entries' counters. */
 194         struct xt_counters __user *counters;
 195
 196         /* The entries (hang off end: not really an array). */
 197         struct ipt_entry entries[0];
 198 };
 199
 200 /* The argument to IPT_SO_ADD_COUNTERS. */
 201 #define ipt_counters_info xt_counters_info
 202
 203 /* The argument to IPT_SO_GET_ENTRIES. */
 204 struct ipt_get_entries
 205 {
 206         /* Which table: user fills this in. */
 207         char name[IPT_TABLE_MAXNAMELEN];
 208
 209         /* User fills this in: total entry size. */
 210         unsigned int size;
 211
 212         /* The entries. */
 213         struct ipt_entry entrytable[0];
 214 };
 215
 216 /* Standard return verdict, or do jump. */
 217 #define IPT_STANDARD_TARGET XT_STANDARD_TARGET
 218 /* Error verdict. */
 219 #define IPT_ERROR_TARGET XT_ERROR_TARGET
 220
 221 /* Helper functions */
 222 static __inline__ struct ipt_entry_target *
 223 ipt_get_target(struct ipt_entry *e)
 224 {
 225         return (void *)e + e->target_offset;
 226 }
 227
 228 /* fn returns 0 to continue iteration */
 229 #define IPT_MATCH_ITERATE(e, fn, args...)       \
 230 ({                                              \
 231         unsigned int __i;                       \
 232         int __ret = 0;                          \
 233         struct ipt_entry_match *__match;        \
 234                                                 \
 235         for (__i = sizeof(struct ipt_entry);    \
 236              __i < (e)->target_offset;          \
 237              __i += __match->u.match_size) {    \
 238                 __match = (void *)(e) + __i;    \
 239                                                 \
 240                 __ret = fn(__match , ## args);  \
 241                 if (__ret != 0)                 \
 242                         break;                  \
 243         }                                       \
 244         __ret;                                  \
 245 })
 246
 247 /* fn returns 0 to continue iteration */
 248 #define IPT_ENTRY_ITERATE(entries, size, fn, args...)           \
 249 ({                                                              \
 250         unsigned int __i;                                       \
 251         int __ret = 0;                                          \
 252         struct ipt_entry *__entry;                              \
 253                                                                 \
 254         for (__i = 0; __i < (size); __i += __entry->next_offset) { \
 255                 __entry = (void *)(entries) + __i;              \
 256                                                                 \
 257                 __ret = fn(__entry , ## args);                  \
 258                 if (__ret != 0)                                 \
 259                         break;                                  \
 260         }                                                       \
 261         __ret;                                                  \
 262 })
 263
 264 /*
 265  *      Main firewall chains definitions and global var's definitions.
 266  */
 267 #ifdef __KERNEL__
 268
 269 #include <linux/init.h>
 270 extern void ipt_init(void) __init;
 271
 272 #define ipt_register_target(tgt)        \
 273 ({      (tgt)->family = AF_INET;        \
 274         xt_register_target(tgt); })
 275 #define ipt_unregister_target(tgt) xt_unregister_target(tgt)
 276
 277 #define ipt_register_match(mtch)        \
 278 ({      (mtch)->family = AF_INET;       \
 279         xt_register_match(mtch); })
 280 #define ipt_unregister_match(mtch) xt_unregister_match(mtch)
 281
 282 //#define ipt_register_table(tbl, repl) xt_register_table(AF_INET, tbl, repl)
 283 //#define ipt_unregister_table(tbl) xt_unregister_table(AF_INET, tbl)
 284
 285 extern int ipt_register_table(struct ipt_table *table,
 286                               const struct ipt_replace *repl);
 287 extern void ipt_unregister_table(struct ipt_table *table);
 288
 289 /* net/sched/ipt.c: Gimme access to your targets!  Gets target->me. */
 290 extern struct ipt_target *ipt_find_target(const char *name, u8 revision);
 291
 292 /* Standard entry. */
 293 struct ipt_standard
 294 {
 295         struct ipt_entry entry;
 296         struct ipt_standard_target target;
 297 };
 298
 299 struct ipt_error_target
 300 {
 301         struct ipt_entry_target target;
 302         char errorname[IPT_FUNCTION_MAXNAMELEN];
 303 };
 304
 305 struct ipt_error
 306 {
 307         struct ipt_entry entry;
 308         struct ipt_error_target target;
 309 };
 310
 311 extern unsigned int ipt_do_table(struct sk_buff **pskb,
 312                                  unsigned int hook,
 313                                  const struct net_device *in,
 314                                  const struct net_device *out,
 315                                  struct ipt_table *table);
 316
 317 #define IPT_ALIGN(s) XT_ALIGN(s)
 318
 319 #ifdef CONFIG_COMPAT
 320 #include <net/compat.h>
 321
 322 struct compat_ipt_entry
 323 {
 324         struct ipt_ip ip;
 325         compat_uint_t nfcache;
 326         u_int16_t target_offset;
 327         u_int16_t next_offset;
 328         compat_uint_t comefrom;
 329         struct compat_xt_counters counters;
 330         unsigned char elems[0];
 331 };
 332
 333 #define COMPAT_IPT_ALIGN(s)     COMPAT_XT_ALIGN(s)
 334
 335 #endif /* CONFIG_COMPAT */
 336 #endif /*__KERNEL__*/
 337 #endif /* _IPTABLES_H */