LXR linux/include/linux/netfilter_ipv4/ip

   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/in.h>
  21#include <linux/ip.h>
  22#include <linux/skbuff.h>
  23#endif
  24#include <linux/types.h>
  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_TABLE_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. */
  38struct 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 */
  79struct 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 *
 106 * ATTENTION: check linux/in.h before adding new number here.
 107 */
 108#define IPT_BASE_CTL            64
 109
 110#define IPT_SO_SET_REPLACE      (IPT_BASE_CTL)
 111#define IPT_SO_SET_ADD_COUNTERS (IPT_BASE_CTL + 1)
 112#define IPT_SO_SET_MAX          IPT_SO_SET_ADD_COUNTERS
 113
 114#define IPT_SO_GET_INFO                 (IPT_BASE_CTL)
 115#define IPT_SO_GET_ENTRIES              (IPT_BASE_CTL + 1)
 116#define IPT_SO_GET_REVISION_MATCH       (IPT_BASE_CTL + 2)
 117#define IPT_SO_GET_REVISION_TARGET      (IPT_BASE_CTL + 3)
 118#define IPT_SO_GET_MAX                  IPT_SO_GET_REVISION_TARGET
 119
 120#define IPT_CONTINUE XT_CONTINUE
 121#define IPT_RETURN XT_RETURN
 122
 123#include <linux/netfilter/xt_tcpudp.h>
 124#define ipt_udp xt_udp
 125#define ipt_tcp xt_tcp
 126
 127#define IPT_TCP_INV_SRCPT       XT_TCP_INV_SRCPT
 128#define IPT_TCP_INV_DSTPT       XT_TCP_INV_DSTPT
 129#define IPT_TCP_INV_FLAGS       XT_TCP_INV_FLAGS
 130#define IPT_TCP_INV_OPTION      XT_TCP_INV_OPTION
 131#define IPT_TCP_INV_MASK        XT_TCP_INV_MASK
 132
 133#define IPT_UDP_INV_SRCPT       XT_UDP_INV_SRCPT
 134#define IPT_UDP_INV_DSTPT       XT_UDP_INV_DSTPT
 135#define IPT_UDP_INV_MASK        XT_UDP_INV_MASK
 136
 137/* ICMP matching stuff */
 138struct ipt_icmp
 139{
 140        u_int8_t type;                          /* type to match */
 141        u_int8_t code[2];                       /* range of code */
 142        u_int8_t invflags;                      /* Inverse flags */
 143};
 144
 145/* Values for "inv" field for struct ipt_icmp. */
 146#define IPT_ICMP_INV    0x01    /* Invert the sense of type/code test */
 147
 148/* The argument to IPT_SO_GET_INFO */
 149struct ipt_getinfo
 150{
 151        /* Which table: caller fills this in. */
 152        char name[IPT_TABLE_MAXNAMELEN];
 153
 154        /* Kernel fills these in. */
 155        /* Which hook entry points are valid: bitmask */
 156        unsigned int valid_hooks;
 157
 158        /* Hook entry points: one per netfilter hook. */
 159        unsigned int hook_entry[NF_INET_NUMHOOKS];
 160
 161        /* Underflow points. */
 162        unsigned int underflow[NF_INET_NUMHOOKS];
 163
 164        /* Number of entries */
 165        unsigned int num_entries;
 166
 167        /* Size of entries. */
 168        unsigned int size;
 169};
 170
 171/* The argument to IPT_SO_SET_REPLACE. */
 172struct ipt_replace
 173{
 174        /* Which table. */
 175        char name[IPT_TABLE_MAXNAMELEN];
 176
 177        /* Which hook entry points are valid: bitmask.  You can't
 178           change this. */
 179        unsigned int valid_hooks;
 180
 181        /* Number of entries */
 182        unsigned int num_entries;
 183
 184        /* Total size of new entries */
 185        unsigned int size;
 186
 187        /* Hook entry points. */
 188        unsigned int hook_entry[NF_INET_NUMHOOKS];
 189
 190        /* Underflow points. */
 191        unsigned int underflow[NF_INET_NUMHOOKS];
 192
 193        /* Information about old entries: */
 194        /* Number of counters (must be equal to current number of entries). */
 195        unsigned int num_counters;
 196        /* The old entries' counters. */
 197        struct xt_counters __user *counters;
 198
 199        /* The entries (hang off end: not really an array). */
 200        struct ipt_entry entries[0];
 201};
 202
 203/* The argument to IPT_SO_ADD_COUNTERS. */
 204#define ipt_counters_info xt_counters_info
 205
 206/* The argument to IPT_SO_GET_ENTRIES. */
 207struct ipt_get_entries
 208{
 209        /* Which table: user fills this in. */
 210        char name[IPT_TABLE_MAXNAMELEN];
 211
 212        /* User fills this in: total entry size. */
 213        unsigned int size;
 214
 215        /* The entries. */
 216        struct ipt_entry entrytable[0];
 217};
 218
 219/* Standard return verdict, or do jump. */
 220#define IPT_STANDARD_TARGET XT_STANDARD_TARGET
 221/* Error verdict. */
 222#define IPT_ERROR_TARGET XT_ERROR_TARGET
 223
 224/* Helper functions */
 225static __inline__ struct ipt_entry_target *
 226ipt_get_target(struct ipt_entry *e)
 227{
 228        return (void *)e + e->target_offset;
 229}
 230
 231/* fn returns 0 to continue iteration */
 232#define IPT_MATCH_ITERATE(e, fn, args...) \
 233        XT_MATCH_ITERATE(struct ipt_entry, e, fn, ## args)
 234
 235/* fn returns 0 to continue iteration */
 236#define IPT_ENTRY_ITERATE(entries, size, fn, args...) \
 237        XT_ENTRY_ITERATE(struct ipt_entry, entries, size, fn, ## args)
 238
 239/*
 240 *      Main firewall chains definitions and global var's definitions.
 241 */
 242#ifdef __KERNEL__
 243
 244#include <linux/init.h>
 245extern void ipt_init(void) __init;
 246
 247extern struct xt_table *ipt_register_table(struct net *net,
 248                                           const struct xt_table *table,
 249                                           const struct ipt_replace *repl);
 250extern void ipt_unregister_table(struct xt_table *table);
 251
 252/* Standard entry. */
 253struct ipt_standard
 254{
 255        struct ipt_entry entry;
 256        struct ipt_standard_target target;
 257};
 258
 259struct ipt_error_target
 260{
 261        struct ipt_entry_target target;
 262        char errorname[IPT_FUNCTION_MAXNAMELEN];
 263};
 264
 265struct ipt_error
 266{
 267        struct ipt_entry entry;
 268        struct ipt_error_target target;
 269};
 270
 271#define IPT_ENTRY_INIT(__size)                                                 \
 272{                                                                              \
 273        .target_offset  = sizeof(struct ipt_entry),                            \
 274        .next_offset    = (__size),                                            \
 275}
 276
 277#define IPT_STANDARD_INIT(__verdict)                                           \
 278{                                                                              \
 279        .entry          = IPT_ENTRY_INIT(sizeof(struct ipt_standard)),         \
 280        .target         = XT_TARGET_INIT(IPT_STANDARD_TARGET,                  \
 281                                         sizeof(struct xt_standard_target)),   \
 282        .target.verdict = -(__verdict) - 1,                                    \
 283}
 284
 285#define IPT_ERROR_INIT                                                         \
 286{                                                                              \
 287        .entry          = IPT_ENTRY_INIT(sizeof(struct ipt_error)),            \
 288        .target         = XT_TARGET_INIT(IPT_ERROR_TARGET,                     \
 289                                         sizeof(struct ipt_error_target)),     \
 290        .target.errorname = "ERROR",                                           \
 291}
 292
 293extern unsigned int ipt_do_table(struct sk_buff *skb,
 294                                 unsigned int hook,
 295                                 const struct net_device *in,
 296                                 const struct net_device *out,
 297                                 struct xt_table *table);
 298
 299#define IPT_ALIGN(s) XT_ALIGN(s)
 300
 301#ifdef CONFIG_COMPAT
 302#include <net/compat.h>
 303
 304struct compat_ipt_entry
 305{
 306        struct ipt_ip ip;
 307        compat_uint_t nfcache;
 308        u_int16_t target_offset;
 309        u_int16_t next_offset;
 310        compat_uint_t comefrom;
 311        struct compat_xt_counters counters;
 312        unsigned char elems[0];
 313};
 314
 315/* Helper functions */
 316static inline struct ipt_entry_target *
 317compat_ipt_get_target(struct compat_ipt_entry *e)
 318{
 319        return (void *)e + e->target_offset;
 320}
 321
 322#define COMPAT_IPT_ALIGN(s)     COMPAT_XT_ALIGN(s)
 323
 324/* fn returns 0 to continue iteration */
 325#define COMPAT_IPT_MATCH_ITERATE(e, fn, args...) \
 326        XT_MATCH_ITERATE(struct compat_ipt_entry, e, fn, ## args)
 327
 328/* fn returns 0 to continue iteration */
 329#define COMPAT_IPT_ENTRY_ITERATE(entries, size, fn, args...) \
 330        XT_ENTRY_ITERATE(struct compat_ipt_entry, entries, size, fn, ## args)
 331
 332/* fn returns 0 to continue iteration */
 333#define COMPAT_IPT_ENTRY_ITERATE_CONTINUE(entries, size, n, fn, args...) \
 334        XT_ENTRY_ITERATE_CONTINUE(struct compat_ipt_entry, entries, size, n, \
 335                                  fn, ## args)
 336
 337#endif /* CONFIG_COMPAT */
 338#endif /*__KERNEL__*/
 339#endif /* _IPTABLES_H */
 340