LXR linux/include/linux/netfilter_arp/arp

   1/*
   2 *      Format of an ARP firewall descriptor
   3 *
   4 *      src, tgt, src_mask, tgt_mask, arpop, arpop_mask are always stored in
   5 *      network byte order.
   6 *      flags are stored in host byte order (of course).
   7 */
   8
   9#ifndef _ARPTABLES_H
  10#define _ARPTABLES_H
  11
  12#ifdef __KERNEL__
  13#include <linux/if.h>
  14#include <linux/in.h>
  15#include <linux/if_arp.h>
  16#include <linux/skbuff.h>
  17#endif
  18#include <linux/types.h>
  19#include <linux/compiler.h>
  20#include <linux/netfilter_arp.h>
  21
  22#include <linux/netfilter/x_tables.h>
  23
  24#define ARPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
  25#define ARPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
  26
  27#define ARPT_DEV_ADDR_LEN_MAX 16
  28
  29struct arpt_devaddr_info {
  30        char addr[ARPT_DEV_ADDR_LEN_MAX];
  31        char mask[ARPT_DEV_ADDR_LEN_MAX];
  32};
  33
  34/* Yes, Virginia, you have to zero the padding. */
  35struct arpt_arp {
  36        /* Source and target IP addr */
  37        struct in_addr src, tgt;
  38        /* Mask for src and target IP addr */
  39        struct in_addr smsk, tmsk;
  40
  41        /* Device hw address length, src+target device addresses */
  42        u_int8_t arhln, arhln_mask;
  43        struct arpt_devaddr_info src_devaddr;
  44        struct arpt_devaddr_info tgt_devaddr;
  45
  46        /* ARP operation code. */
  47        __be16 arpop, arpop_mask;
  48
  49        /* ARP hardware address and protocol address format. */
  50        __be16 arhrd, arhrd_mask;
  51        __be16 arpro, arpro_mask;
  52
  53        /* The protocol address length is only accepted if it is 4
  54         * so there is no use in offering a way to do filtering on it.
  55         */
  56
  57        char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
  58        unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
  59
  60        /* Flags word */
  61        u_int8_t flags;
  62        /* Inverse flags */
  63        u_int16_t invflags;
  64};
  65
  66#define arpt_entry_target xt_entry_target
  67#define arpt_standard_target xt_standard_target
  68
  69/* Values for "flag" field in struct arpt_ip (general arp structure).
  70 * No flags defined yet.
  71 */
  72#define ARPT_F_MASK             0x00    /* All possible flag bits mask. */
  73
  74/* Values for "inv" field in struct arpt_arp. */
  75#define ARPT_INV_VIA_IN         0x0001  /* Invert the sense of IN IFACE. */
  76#define ARPT_INV_VIA_OUT        0x0002  /* Invert the sense of OUT IFACE */
  77#define ARPT_INV_SRCIP          0x0004  /* Invert the sense of SRC IP. */
  78#define ARPT_INV_TGTIP          0x0008  /* Invert the sense of TGT IP. */
  79#define ARPT_INV_SRCDEVADDR     0x0010  /* Invert the sense of SRC DEV ADDR. */
  80#define ARPT_INV_TGTDEVADDR     0x0020  /* Invert the sense of TGT DEV ADDR. */
  81#define ARPT_INV_ARPOP          0x0040  /* Invert the sense of ARP OP. */
  82#define ARPT_INV_ARPHRD         0x0080  /* Invert the sense of ARP HRD. */
  83#define ARPT_INV_ARPPRO         0x0100  /* Invert the sense of ARP PRO. */
  84#define ARPT_INV_ARPHLN         0x0200  /* Invert the sense of ARP HLN. */
  85#define ARPT_INV_MASK           0x03FF  /* All possible flag bits mask. */
  86
  87/* This structure defines each of the firewall rules.  Consists of 3
  88   parts which are 1) general ARP header stuff 2) match specific
  89   stuff 3) the target to perform if the rule matches */
  90struct arpt_entry
  91{
  92        struct arpt_arp arp;
  93
  94        /* Size of arpt_entry + matches */
  95        u_int16_t target_offset;
  96        /* Size of arpt_entry + matches + target */
  97        u_int16_t next_offset;
  98
  99        /* Back pointer */
 100        unsigned int comefrom;
 101
 102        /* Packet and byte counters. */
 103        struct xt_counters counters;
 104
 105        /* The matches (if any), then the target. */
 106        unsigned char elems[0];
 107};
 108
 109/*
 110 * New IP firewall options for [gs]etsockopt at the RAW IP level.
 111 * Unlike BSD Linux inherits IP options so you don't have to use a raw
 112 * socket for this. Instead we check rights in the calls.
 113 *
 114 * ATTENTION: check linux/in.h before adding new number here.
 115 */
 116#define ARPT_BASE_CTL           96
 117
 118#define ARPT_SO_SET_REPLACE             (ARPT_BASE_CTL)
 119#define ARPT_SO_SET_ADD_COUNTERS        (ARPT_BASE_CTL + 1)
 120#define ARPT_SO_SET_MAX                 ARPT_SO_SET_ADD_COUNTERS
 121
 122#define ARPT_SO_GET_INFO                (ARPT_BASE_CTL)
 123#define ARPT_SO_GET_ENTRIES             (ARPT_BASE_CTL + 1)
 124/* #define ARPT_SO_GET_REVISION_MATCH   (APRT_BASE_CTL + 2) */
 125#define ARPT_SO_GET_REVISION_TARGET     (ARPT_BASE_CTL + 3)
 126#define ARPT_SO_GET_MAX                 (ARPT_SO_GET_REVISION_TARGET)
 127
 128/* CONTINUE verdict for targets */
 129#define ARPT_CONTINUE XT_CONTINUE
 130
 131/* For standard target */
 132#define ARPT_RETURN XT_RETURN
 133
 134/* The argument to ARPT_SO_GET_INFO */
 135struct arpt_getinfo
 136{
 137        /* Which table: caller fills this in. */
 138        char name[ARPT_TABLE_MAXNAMELEN];
 139
 140        /* Kernel fills these in. */
 141        /* Which hook entry points are valid: bitmask */
 142        unsigned int valid_hooks;
 143
 144        /* Hook entry points: one per netfilter hook. */
 145        unsigned int hook_entry[NF_ARP_NUMHOOKS];
 146
 147        /* Underflow points. */
 148        unsigned int underflow[NF_ARP_NUMHOOKS];
 149
 150        /* Number of entries */
 151        unsigned int num_entries;
 152
 153        /* Size of entries. */
 154        unsigned int size;
 155};
 156
 157/* The argument to ARPT_SO_SET_REPLACE. */
 158struct arpt_replace
 159{
 160        /* Which table. */
 161        char name[ARPT_TABLE_MAXNAMELEN];
 162
 163        /* Which hook entry points are valid: bitmask.  You can't
 164           change this. */
 165        unsigned int valid_hooks;
 166
 167        /* Number of entries */
 168        unsigned int num_entries;
 169
 170        /* Total size of new entries */
 171        unsigned int size;
 172
 173        /* Hook entry points. */
 174        unsigned int hook_entry[NF_ARP_NUMHOOKS];
 175
 176        /* Underflow points. */
 177        unsigned int underflow[NF_ARP_NUMHOOKS];
 178
 179        /* Information about old entries: */
 180        /* Number of counters (must be equal to current number of entries). */
 181        unsigned int num_counters;
 182        /* The old entries' counters. */
 183        struct xt_counters __user *counters;
 184
 185        /* The entries (hang off end: not really an array). */
 186        struct arpt_entry entries[0];
 187};
 188
 189/* The argument to ARPT_SO_ADD_COUNTERS. */
 190#define arpt_counters_info xt_counters_info
 191#define arpt_counters xt_counters
 192
 193/* The argument to ARPT_SO_GET_ENTRIES. */
 194struct arpt_get_entries
 195{
 196        /* Which table: user fills this in. */
 197        char name[ARPT_TABLE_MAXNAMELEN];
 198
 199        /* User fills this in: total entry size. */
 200        unsigned int size;
 201
 202        /* The entries. */
 203        struct arpt_entry entrytable[0];
 204};
 205
 206/* Standard return verdict, or do jump. */
 207#define ARPT_STANDARD_TARGET XT_STANDARD_TARGET
 208/* Error verdict. */
 209#define ARPT_ERROR_TARGET XT_ERROR_TARGET
 210
 211/* Helper functions */
 212static __inline__ struct arpt_entry_target *arpt_get_target(struct arpt_entry *e)
 213{
 214        return (void *)e + e->target_offset;
 215}
 216
 217/* fn returns 0 to continue iteration */
 218#define ARPT_ENTRY_ITERATE(entries, size, fn, args...) \
 219        XT_ENTRY_ITERATE(struct arpt_entry, entries, size, fn, ## args)
 220
 221/*
 222 *      Main firewall chains definitions and global var's definitions.
 223 */
 224#ifdef __KERNEL__
 225
 226/* Standard entry. */
 227struct arpt_standard
 228{
 229        struct arpt_entry entry;
 230        struct arpt_standard_target target;
 231};
 232
 233struct arpt_error_target
 234{
 235        struct arpt_entry_target target;
 236        char errorname[ARPT_FUNCTION_MAXNAMELEN];
 237};
 238
 239struct arpt_error
 240{
 241        struct arpt_entry entry;
 242        struct arpt_error_target target;
 243};
 244
 245#define ARPT_ENTRY_INIT(__size)                                                \
 246{                                                                              \
 247        .target_offset  = sizeof(struct arpt_entry),                           \
 248        .next_offset    = (__size),                                            \
 249}
 250
 251#define ARPT_STANDARD_INIT(__verdict)                                          \
 252{                                                                              \
 253        .entry          = ARPT_ENTRY_INIT(sizeof(struct arpt_standard)),       \
 254        .target         = XT_TARGET_INIT(ARPT_STANDARD_TARGET,                 \
 255                                         sizeof(struct arpt_standard_target)), \
 256        .target.verdict = -(__verdict) - 1,                                    \
 257}
 258
 259#define ARPT_ERROR_INIT                                                        \
 260{                                                                              \
 261        .entry          = ARPT_ENTRY_INIT(sizeof(struct arpt_error)),          \
 262        .target         = XT_TARGET_INIT(ARPT_ERROR_TARGET,                    \
 263                                         sizeof(struct arpt_error_target)),    \
 264        .target.errorname = "ERROR",                                           \
 265}
 266
 267extern struct xt_table *arpt_register_table(struct net *net,
 268                                            const struct xt_table *table,
 269                                            const struct arpt_replace *repl);
 270extern void arpt_unregister_table(struct xt_table *table);
 271extern unsigned int arpt_do_table(struct sk_buff *skb,
 272                                  unsigned int hook,
 273                                  const struct net_device *in,
 274                                  const struct net_device *out,
 275                                  struct xt_table *table);
 276
 277#define ARPT_ALIGN(s) XT_ALIGN(s)
 278
 279#ifdef CONFIG_COMPAT
 280#include <net/compat.h>
 281
 282struct compat_arpt_entry
 283{
 284        struct arpt_arp arp;
 285        u_int16_t target_offset;
 286        u_int16_t next_offset;
 287        compat_uint_t comefrom;
 288        struct compat_xt_counters counters;
 289        unsigned char elems[0];
 290};
 291
 292static inline struct arpt_entry_target *
 293compat_arpt_get_target(struct compat_arpt_entry *e)
 294{
 295        return (void *)e + e->target_offset;
 296}
 297
 298#define COMPAT_ARPT_ALIGN(s)    COMPAT_XT_ALIGN(s)
 299
 300/* fn returns 0 to continue iteration */
 301#define COMPAT_ARPT_ENTRY_ITERATE(entries, size, fn, args...) \
 302        XT_ENTRY_ITERATE(struct compat_arpt_entry, entries, size, fn, ## args)
 303
 304#define COMPAT_ARPT_ENTRY_ITERATE_CONTINUE(entries, size, n, fn, args...) \
 305        XT_ENTRY_ITERATE_CONTINUE(struct compat_arpt_entry, entries, size, n, \
 306                                  fn, ## args)
 307
 308#endif /* CONFIG_COMPAT */
 309#endif /*__KERNEL__*/
 310#endif /* _ARPTABLES_H */
 311