1/* 2 * ebtables 3 * 4 * Authors: 5 * Bart De Schuymer <bdschuym@pandora.be> 6 * 7 * ebtables.c,v 2.0, April, 2002 8 * 9 * This code is stongly inspired on the iptables code which is 10 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling 11 */ 12 13#ifndef __LINUX_BRIDGE_EFF_H 14#define __LINUX_BRIDGE_EFF_H 15#include <linux/if.h> 16#include <linux/netfilter_bridge.h> 17#include <linux/if_ether.h> 18 19#define EBT_TABLE_MAXNAMELEN 32 20#define EBT_CHAIN_MAXNAMELEN EBT_TABLE_MAXNAMELEN 21#define EBT_FUNCTION_MAXNAMELEN EBT_TABLE_MAXNAMELEN 22 23/* verdicts >0 are "branches" */ 24#define EBT_ACCEPT -1 25#define EBT_DROP -2 26#define EBT_CONTINUE -3 27#define EBT_RETURN -4 28#define NUM_STANDARD_TARGETS 4 29/* ebtables target modules store the verdict inside an int. We can 30 * reclaim a part of this int for backwards compatible extensions. 31 * The 4 lsb are more than enough to store the verdict. */ 32#define EBT_VERDICT_BITS 0x0000000F 33 34struct xt_match; 35struct xt_target; 36 37struct ebt_counter { 38 uint64_t pcnt; 39 uint64_t bcnt; 40}; 41 42struct ebt_replace { 43 char name[EBT_TABLE_MAXNAMELEN]; 44 unsigned int valid_hooks; 45 /* nr of rules in the table */ 46 unsigned int nentries; 47 /* total size of the entries */ 48 unsigned int entries_size; 49 /* start of the chains */ 50 struct ebt_entries __user *hook_entry[NF_BR_NUMHOOKS]; 51 /* nr of counters userspace expects back */ 52 unsigned int num_counters; 53 /* where the kernel will put the old counters */ 54 struct ebt_counter __user *counters; 55 char __user *entries; 56}; 57 58struct ebt_replace_kernel { 59 char name[EBT_TABLE_MAXNAMELEN]; 60 unsigned int valid_hooks; 61 /* nr of rules in the table */ 62 unsigned int nentries; 63 /* total size of the entries */ 64 unsigned int entries_size; 65 /* start of the chains */ 66 struct ebt_entries *hook_entry[NF_BR_NUMHOOKS]; 67 /* nr of counters userspace expects back */ 68 unsigned int num_counters; 69 /* where the kernel will put the old counters */ 70 struct ebt_counter *counters; 71 char *entries; 72}; 73 74struct ebt_entries { 75 /* this field is always set to zero 76 * See EBT_ENTRY_OR_ENTRIES. 77 * Must be same size as ebt_entry.bitmask */ 78 unsigned int distinguisher; 79 /* the chain name */ 80 char name[EBT_CHAIN_MAXNAMELEN]; 81 /* counter offset for this chain */ 82 unsigned int counter_offset; 83 /* one standard (accept, drop, return) per hook */ 84 int policy; 85 /* nr. of entries */ 86 unsigned int nentries; 87 /* entry list */ 88 char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace)))); 89}; 90 91/* used for the bitmask of struct ebt_entry */ 92 93/* This is a hack to make a difference between an ebt_entry struct and an 94 * ebt_entries struct when traversing the entries from start to end. 95 * Using this simplifies the code alot, while still being able to use 96 * ebt_entries. 97 * Contrary, iptables doesn't use something like ebt_entries and therefore uses 98 * different techniques for naming the policy and such. So, iptables doesn't 99 * need a hack like this. 100 */ 101#define EBT_ENTRY_OR_ENTRIES 0x01 102/* these are the normal masks */ 103#define EBT_NOPROTO 0x02 104#define EBT_802_3 0x04 105#define EBT_SOURCEMAC 0x08 106#define EBT_DESTMAC 0x10 107#define EBT_F_MASK (EBT_NOPROTO | EBT_802_3 | EBT_SOURCEMAC | EBT_DESTMAC \ 108 | EBT_ENTRY_OR_ENTRIES) 109 110#define EBT_IPROTO 0x01 111#define EBT_IIN 0x02 112#define EBT_IOUT 0x04 113#define EBT_ISOURCE 0x8 114#define EBT_IDEST 0x10 115#define EBT_ILOGICALIN 0x20 116#define EBT_ILOGICALOUT 0x40 117#define EBT_INV_MASK (EBT_IPROTO | EBT_IIN | EBT_IOUT | EBT_ILOGICALIN \ 118 | EBT_ILOGICALOUT | EBT_ISOURCE | EBT_IDEST) 119 120struct ebt_entry_match { 121 union { 122 char name[EBT_FUNCTION_MAXNAMELEN]; 123 struct xt_match *match; 124 } u; 125 /* size of data */ 126 unsigned int match_size; 127 unsigned char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace)))); 128}; 129 130struct ebt_entry_watcher { 131 union { 132 char name[EBT_FUNCTION_MAXNAMELEN]; 133 struct xt_target *watcher; 134 } u; 135 /* size of data */ 136 unsigned int watcher_size; 137 unsigned char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace)))); 138}; 139 140struct ebt_entry_target { 141 union { 142 char name[EBT_FUNCTION_MAXNAMELEN]; 143 struct xt_target *target; 144 } u; 145 /* size of data */ 146 unsigned int target_size; 147 unsigned char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace)))); 148}; 149 150#define EBT_STANDARD_TARGET "standard" 151struct ebt_standard_target { 152 struct ebt_entry_target target; 153 int verdict; 154}; 155 156/* one entry */ 157struct ebt_entry { 158 /* this needs to be the first field */ 159 unsigned int bitmask; 160 unsigned int invflags; 161 __be16 ethproto; 162 /* the physical in-dev */ 163 char in[IFNAMSIZ]; 164 /* the logical in-dev */ 165 char logical_in[IFNAMSIZ]; 166 /* the physical out-dev */ 167 char out[IFNAMSIZ]; 168 /* the logical out-dev */ 169 char logical_out[IFNAMSIZ]; 170 unsigned char sourcemac[ETH_ALEN]; 171 unsigned char sourcemsk[ETH_ALEN]; 172 unsigned char destmac[ETH_ALEN]; 173 unsigned char destmsk[ETH_ALEN]; 174 /* sizeof ebt_entry + matches */ 175 unsigned int watchers_offset; 176 /* sizeof ebt_entry + matches + watchers */ 177 unsigned int target_offset; 178 /* sizeof ebt_entry + matches + watchers + target */ 179 unsigned int next_offset; 180 unsigned char elems[0] __attribute__ ((aligned (__alignof__(struct ebt_replace)))); 181}; 182 183/* {g,s}etsockopt numbers */ 184#define EBT_BASE_CTL 128 185 186#define EBT_SO_SET_ENTRIES (EBT_BASE_CTL) 187#define EBT_SO_SET_COUNTERS (EBT_SO_SET_ENTRIES+1) 188#define EBT_SO_SET_MAX (EBT_SO_SET_COUNTERS+1) 189 190#define EBT_SO_GET_INFO (EBT_BASE_CTL) 191#define EBT_SO_GET_ENTRIES (EBT_SO_GET_INFO+1) 192#define EBT_SO_GET_INIT_INFO (EBT_SO_GET_ENTRIES+1) 193#define EBT_SO_GET_INIT_ENTRIES (EBT_SO_GET_INIT_INFO+1) 194#define EBT_SO_GET_MAX (EBT_SO_GET_INIT_ENTRIES+1) 195 196#ifdef __KERNEL__ 197 198/* return values for match() functions */ 199#define EBT_MATCH 0 200#define EBT_NOMATCH 1 201 202struct ebt_match { 203 struct list_head list; 204 const char name[EBT_FUNCTION_MAXNAMELEN]; 205 bool (*match)(const struct sk_buff *skb, const struct net_device *in, 206 const struct net_device *out, const struct xt_match *match, 207 const void *matchinfo, int offset, unsigned int protoff, 208 bool *hotdrop); 209 bool (*checkentry)(const char *table, const void *entry, 210 const struct xt_match *match, void *matchinfo, 211 unsigned int hook_mask); 212 void (*destroy)(const struct xt_match *match, void *matchinfo); 213 unsigned int matchsize; 214 u_int8_t revision; 215 u_int8_t family; 216 struct module *me; 217}; 218 219struct ebt_watcher { 220 struct list_head list; 221 const char name[EBT_FUNCTION_MAXNAMELEN]; 222 unsigned int (*target)(struct sk_buff *skb, 223 const struct net_device *in, const struct net_device *out, 224 unsigned int hook_num, const struct xt_target *target, 225 const void *targinfo); 226 bool (*checkentry)(const char *table, const void *entry, 227 const struct xt_target *target, void *targinfo, 228 unsigned int hook_mask); 229 void (*destroy)(const struct xt_target *target, void *targinfo); 230 unsigned int targetsize; 231 u_int8_t revision; 232 u_int8_t family; 233 struct module *me; 234}; 235 236struct ebt_target { 237 struct list_head list; 238 const char name[EBT_FUNCTION_MAXNAMELEN]; 239 /* returns one of the standard EBT_* verdicts */ 240 unsigned int (*target)(struct sk_buff *skb, 241 const struct net_device *in, const struct net_device *out, 242 unsigned int hook_num, const struct xt_target *target, 243 const void *targinfo); 244 bool (*checkentry)(const char *table, const void *entry, 245 const struct xt_target *target, void *targinfo, 246 unsigned int hook_mask); 247 void (*destroy)(const struct xt_target *target, void *targinfo); 248 unsigned int targetsize; 249 u_int8_t revision; 250 u_int8_t family; 251 struct module *me; 252}; 253 254/* used for jumping from and into user defined chains (udc) */ 255struct ebt_chainstack { 256 struct ebt_entries *chaininfo; /* pointer to chain data */ 257 struct ebt_entry *e; /* pointer to entry data */ 258 unsigned int n; /* n'th entry */ 259}; 260 261struct ebt_table_info { 262 /* total size of the entries */ 263 unsigned int entries_size; 264 unsigned int nentries; 265 /* pointers to the start of the chains */ 266 struct ebt_entries *hook_entry[NF_BR_NUMHOOKS]; 267 /* room to maintain the stack used for jumping from and into udc */ 268 struct ebt_chainstack **chainstack; 269 char *entries; 270 struct ebt_counter counters[0] ____cacheline_aligned; 271}; 272 273struct ebt_table { 274 struct list_head list; 275 char name[EBT_TABLE_MAXNAMELEN]; 276 struct ebt_replace_kernel *table; 277 unsigned int valid_hooks; 278 rwlock_t lock; 279 /* e.g. could be the table explicitly only allows certain 280 * matches, targets, ... 0 == let it in */ 281 int (*check)(const struct ebt_table_info *info, 282 unsigned int valid_hooks); 283 /* the data used by the kernel */ 284 struct ebt_table_info *private; 285 struct module *me; 286}; 287 288#define EBT_ALIGN(s) (((s) + (__alignof__(struct ebt_replace)-1)) & \ 289 ~(__alignof__(struct ebt_replace)-1)) 290extern struct ebt_table *ebt_register_table(struct net *net, 291 const struct ebt_table *table); 292extern void ebt_unregister_table(struct net *net, struct ebt_table *table); 293extern unsigned int ebt_do_table(unsigned int hook, struct sk_buff *skb, 294 const struct net_device *in, const struct net_device *out, 295 struct ebt_table *table); 296 297/* Used in the kernel match() functions */ 298#define FWINV(bool,invflg) ((bool) ^ !!(info->invflags & invflg)) 299/* True if the hook mask denotes that the rule is in a base chain, 300 * used in the check() functions */ 301#define BASE_CHAIN (par->hook_mask & (1 << NF_BR_NUMHOOKS)) 302/* Clear the bit in the hook mask that tells if the rule is on a base chain */ 303#define CLEAR_BASE_CHAIN_BIT (par->hook_mask &= ~(1 << NF_BR_NUMHOOKS)) 304/* True if the target is not a standard target */ 305#define INVALID_TARGET (info->target < -NUM_STANDARD_TARGETS || info->target >= 0) 306 307#endif /* __KERNEL__ */ 308 309/* blatently stolen from ip_tables.h 310 * fn returns 0 to continue iteration */ 311#define EBT_MATCH_ITERATE(e, fn, args...) \ 312({ \ 313 unsigned int __i; \ 314 int __ret = 0; \ 315 struct ebt_entry_match *__match; \ 316 \ 317 for (__i = sizeof(struct ebt_entry); \ 318 __i < (e)->watchers_offset; \ 319 __i += __match->match_size + \ 320 sizeof(struct ebt_entry_match)) { \ 321 __match = (void *)(e) + __i; \ 322 \ 323 __ret = fn(__match , ## args); \ 324 if (__ret != 0) \ 325 break; \ 326 } \ 327 if (__ret == 0) { \ 328 if (__i != (e)->watchers_offset) \ 329 __ret = -EINVAL; \ 330 } \ 331 __ret; \ 332}) 333 334#define EBT_WATCHER_ITERATE(e, fn, args...) \ 335({ \ 336 unsigned int __i; \ 337 int __ret = 0; \ 338 struct ebt_entry_watcher *__watcher; \ 339 \ 340 for (__i = e->watchers_offset; \ 341 __i < (e)->target_offset; \ 342 __i += __watcher->watcher_size + \ 343 sizeof(struct ebt_entry_watcher)) { \ 344 __watcher = (void *)(e) + __i; \ 345 \ 346 __ret = fn(__watcher , ## args); \ 347 if (__ret != 0) \ 348 break; \ 349 } \ 350 if (__ret == 0) { \ 351 if (__i != (e)->target_offset) \ 352 __ret = -EINVAL; \ 353 } \ 354 __ret; \ 355}) 356 357#define EBT_ENTRY_ITERATE(entries, size, fn, args...) \ 358({ \ 359 unsigned int __i; \ 360 int __ret = 0; \ 361 struct ebt_entry *__entry; \ 362 \ 363 for (__i = 0; __i < (size);) { \ 364 __entry = (void *)(entries) + __i; \ 365 __ret = fn(__entry , ## args); \ 366 if (__ret != 0) \ 367 break; \ 368 if (__entry->bitmask != 0) \ 369 __i += __entry->next_offset; \ 370 else \ 371 __i += sizeof(struct ebt_entries); \ 372 } \ 373 if (__ret == 0) { \ 374 if (__i != (size)) \ 375 __ret = -EINVAL; \ 376 } \ 377 __ret; \ 378}) 379 380#endif 381