Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |
Bart De Schuymer | d12cdc3 | 2006-11-29 02:35:40 +0100 | [diff] [blame] | 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 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
| 34 | struct ebt_counter |
| 35 | { |
| 36 | uint64_t pcnt; |
| 37 | uint64_t bcnt; |
| 38 | }; |
| 39 | |
| 40 | struct ebt_replace |
| 41 | { |
| 42 | char name[EBT_TABLE_MAXNAMELEN]; |
| 43 | unsigned int valid_hooks; |
| 44 | /* nr of rules in the table */ |
| 45 | unsigned int nentries; |
| 46 | /* total size of the entries */ |
| 47 | unsigned int entries_size; |
| 48 | /* start of the chains */ |
Al Viro | 1e419cd | 2006-11-30 19:28:48 -0800 | [diff] [blame] | 49 | struct ebt_entries __user *hook_entry[NF_BR_NUMHOOKS]; |
| 50 | /* nr of counters userspace expects back */ |
| 51 | unsigned int num_counters; |
| 52 | /* where the kernel will put the old counters */ |
| 53 | struct ebt_counter __user *counters; |
| 54 | char __user *entries; |
| 55 | }; |
| 56 | |
| 57 | struct ebt_replace_kernel |
| 58 | { |
| 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 */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 74 | struct 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 | |
| 120 | struct ebt_entry_match |
| 121 | { |
| 122 | union { |
| 123 | char name[EBT_FUNCTION_MAXNAMELEN]; |
| 124 | struct ebt_match *match; |
| 125 | } u; |
| 126 | /* size of data */ |
| 127 | unsigned int match_size; |
| 128 | unsigned char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace)))); |
| 129 | }; |
| 130 | |
| 131 | struct ebt_entry_watcher |
| 132 | { |
| 133 | union { |
| 134 | char name[EBT_FUNCTION_MAXNAMELEN]; |
| 135 | struct ebt_watcher *watcher; |
| 136 | } u; |
| 137 | /* size of data */ |
| 138 | unsigned int watcher_size; |
| 139 | unsigned char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace)))); |
| 140 | }; |
| 141 | |
| 142 | struct ebt_entry_target |
| 143 | { |
| 144 | union { |
| 145 | char name[EBT_FUNCTION_MAXNAMELEN]; |
| 146 | struct ebt_target *target; |
| 147 | } u; |
| 148 | /* size of data */ |
| 149 | unsigned int target_size; |
| 150 | unsigned char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace)))); |
| 151 | }; |
| 152 | |
| 153 | #define EBT_STANDARD_TARGET "standard" |
| 154 | struct ebt_standard_target |
| 155 | { |
| 156 | struct ebt_entry_target target; |
| 157 | int verdict; |
| 158 | }; |
| 159 | |
| 160 | /* one entry */ |
| 161 | struct ebt_entry { |
| 162 | /* this needs to be the first field */ |
| 163 | unsigned int bitmask; |
| 164 | unsigned int invflags; |
Al Viro | 47c183fa | 2006-11-14 21:11:51 -0800 | [diff] [blame] | 165 | __be16 ethproto; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | /* the physical in-dev */ |
| 167 | char in[IFNAMSIZ]; |
| 168 | /* the logical in-dev */ |
| 169 | char logical_in[IFNAMSIZ]; |
| 170 | /* the physical out-dev */ |
| 171 | char out[IFNAMSIZ]; |
| 172 | /* the logical out-dev */ |
| 173 | char logical_out[IFNAMSIZ]; |
| 174 | unsigned char sourcemac[ETH_ALEN]; |
| 175 | unsigned char sourcemsk[ETH_ALEN]; |
| 176 | unsigned char destmac[ETH_ALEN]; |
| 177 | unsigned char destmsk[ETH_ALEN]; |
| 178 | /* sizeof ebt_entry + matches */ |
| 179 | unsigned int watchers_offset; |
| 180 | /* sizeof ebt_entry + matches + watchers */ |
| 181 | unsigned int target_offset; |
| 182 | /* sizeof ebt_entry + matches + watchers + target */ |
| 183 | unsigned int next_offset; |
| 184 | unsigned char elems[0] __attribute__ ((aligned (__alignof__(struct ebt_replace)))); |
| 185 | }; |
| 186 | |
| 187 | /* {g,s}etsockopt numbers */ |
| 188 | #define EBT_BASE_CTL 128 |
| 189 | |
| 190 | #define EBT_SO_SET_ENTRIES (EBT_BASE_CTL) |
| 191 | #define EBT_SO_SET_COUNTERS (EBT_SO_SET_ENTRIES+1) |
| 192 | #define EBT_SO_SET_MAX (EBT_SO_SET_COUNTERS+1) |
| 193 | |
| 194 | #define EBT_SO_GET_INFO (EBT_BASE_CTL) |
| 195 | #define EBT_SO_GET_ENTRIES (EBT_SO_GET_INFO+1) |
| 196 | #define EBT_SO_GET_INIT_INFO (EBT_SO_GET_ENTRIES+1) |
| 197 | #define EBT_SO_GET_INIT_ENTRIES (EBT_SO_GET_INIT_INFO+1) |
| 198 | #define EBT_SO_GET_MAX (EBT_SO_GET_INIT_ENTRIES+1) |
| 199 | |
| 200 | #ifdef __KERNEL__ |
| 201 | |
| 202 | /* return values for match() functions */ |
| 203 | #define EBT_MATCH 0 |
| 204 | #define EBT_NOMATCH 1 |
| 205 | |
| 206 | struct ebt_match |
| 207 | { |
| 208 | struct list_head list; |
| 209 | const char name[EBT_FUNCTION_MAXNAMELEN]; |
| 210 | /* 0 == it matches */ |
| 211 | int (*match)(const struct sk_buff *skb, const struct net_device *in, |
| 212 | const struct net_device *out, const void *matchdata, |
| 213 | unsigned int datalen); |
| 214 | /* 0 == let it in */ |
| 215 | int (*check)(const char *tablename, unsigned int hookmask, |
| 216 | const struct ebt_entry *e, void *matchdata, unsigned int datalen); |
| 217 | void (*destroy)(void *matchdata, unsigned int datalen); |
| 218 | struct module *me; |
| 219 | }; |
| 220 | |
| 221 | struct ebt_watcher |
| 222 | { |
| 223 | struct list_head list; |
| 224 | const char name[EBT_FUNCTION_MAXNAMELEN]; |
| 225 | void (*watcher)(const struct sk_buff *skb, unsigned int hooknr, |
| 226 | const struct net_device *in, const struct net_device *out, |
| 227 | const void *watcherdata, unsigned int datalen); |
| 228 | /* 0 == let it in */ |
| 229 | int (*check)(const char *tablename, unsigned int hookmask, |
| 230 | const struct ebt_entry *e, void *watcherdata, unsigned int datalen); |
| 231 | void (*destroy)(void *watcherdata, unsigned int datalen); |
| 232 | struct module *me; |
| 233 | }; |
| 234 | |
| 235 | struct ebt_target |
| 236 | { |
| 237 | struct list_head list; |
| 238 | const char name[EBT_FUNCTION_MAXNAMELEN]; |
| 239 | /* returns one of the standard verdicts */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 240 | int (*target)(struct sk_buff *skb, unsigned int hooknr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | const struct net_device *in, const struct net_device *out, |
| 242 | const void *targetdata, unsigned int datalen); |
| 243 | /* 0 == let it in */ |
| 244 | int (*check)(const char *tablename, unsigned int hookmask, |
| 245 | const struct ebt_entry *e, void *targetdata, unsigned int datalen); |
| 246 | void (*destroy)(void *targetdata, unsigned int datalen); |
| 247 | struct module *me; |
| 248 | }; |
| 249 | |
| 250 | /* used for jumping from and into user defined chains (udc) */ |
| 251 | struct ebt_chainstack |
| 252 | { |
| 253 | struct ebt_entries *chaininfo; /* pointer to chain data */ |
| 254 | struct ebt_entry *e; /* pointer to entry data */ |
| 255 | unsigned int n; /* n'th entry */ |
| 256 | }; |
| 257 | |
| 258 | struct ebt_table_info |
| 259 | { |
| 260 | /* total size of the entries */ |
| 261 | unsigned int entries_size; |
| 262 | unsigned int nentries; |
| 263 | /* pointers to the start of the chains */ |
| 264 | struct ebt_entries *hook_entry[NF_BR_NUMHOOKS]; |
| 265 | /* room to maintain the stack used for jumping from and into udc */ |
| 266 | struct ebt_chainstack **chainstack; |
| 267 | char *entries; |
| 268 | struct ebt_counter counters[0] ____cacheline_aligned; |
| 269 | }; |
| 270 | |
| 271 | struct ebt_table |
| 272 | { |
| 273 | struct list_head list; |
| 274 | char name[EBT_TABLE_MAXNAMELEN]; |
Al Viro | 1e419cd | 2006-11-30 19:28:48 -0800 | [diff] [blame] | 275 | struct ebt_replace_kernel *table; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | unsigned int valid_hooks; |
| 277 | rwlock_t lock; |
| 278 | /* e.g. could be the table explicitly only allows certain |
| 279 | * matches, targets, ... 0 == let it in */ |
| 280 | int (*check)(const struct ebt_table_info *info, |
| 281 | unsigned int valid_hooks); |
| 282 | /* the data used by the kernel */ |
| 283 | struct ebt_table_info *private; |
| 284 | struct module *me; |
| 285 | }; |
| 286 | |
| 287 | #define EBT_ALIGN(s) (((s) + (__alignof__(struct ebt_replace)-1)) & \ |
| 288 | ~(__alignof__(struct ebt_replace)-1)) |
| 289 | extern int ebt_register_table(struct ebt_table *table); |
| 290 | extern void ebt_unregister_table(struct ebt_table *table); |
| 291 | extern int ebt_register_match(struct ebt_match *match); |
| 292 | extern void ebt_unregister_match(struct ebt_match *match); |
| 293 | extern int ebt_register_watcher(struct ebt_watcher *watcher); |
| 294 | extern void ebt_unregister_watcher(struct ebt_watcher *watcher); |
| 295 | extern int ebt_register_target(struct ebt_target *target); |
| 296 | extern void ebt_unregister_target(struct ebt_target *target); |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 297 | extern unsigned int ebt_do_table(unsigned int hook, struct sk_buff *skb, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | const struct net_device *in, const struct net_device *out, |
| 299 | struct ebt_table *table); |
| 300 | |
| 301 | /* Used in the kernel match() functions */ |
| 302 | #define FWINV(bool,invflg) ((bool) ^ !!(info->invflags & invflg)) |
| 303 | /* True if the hook mask denotes that the rule is in a base chain, |
| 304 | * used in the check() functions */ |
| 305 | #define BASE_CHAIN (hookmask & (1 << NF_BR_NUMHOOKS)) |
| 306 | /* Clear the bit in the hook mask that tells if the rule is on a base chain */ |
| 307 | #define CLEAR_BASE_CHAIN_BIT (hookmask &= ~(1 << NF_BR_NUMHOOKS)) |
| 308 | /* True if the target is not a standard target */ |
| 309 | #define INVALID_TARGET (info->target < -NUM_STANDARD_TARGETS || info->target >= 0) |
| 310 | |
| 311 | #endif /* __KERNEL__ */ |
| 312 | |
| 313 | /* blatently stolen from ip_tables.h |
| 314 | * fn returns 0 to continue iteration */ |
| 315 | #define EBT_MATCH_ITERATE(e, fn, args...) \ |
| 316 | ({ \ |
| 317 | unsigned int __i; \ |
| 318 | int __ret = 0; \ |
| 319 | struct ebt_entry_match *__match; \ |
| 320 | \ |
| 321 | for (__i = sizeof(struct ebt_entry); \ |
| 322 | __i < (e)->watchers_offset; \ |
| 323 | __i += __match->match_size + \ |
| 324 | sizeof(struct ebt_entry_match)) { \ |
| 325 | __match = (void *)(e) + __i; \ |
| 326 | \ |
| 327 | __ret = fn(__match , ## args); \ |
| 328 | if (__ret != 0) \ |
| 329 | break; \ |
| 330 | } \ |
| 331 | if (__ret == 0) { \ |
| 332 | if (__i != (e)->watchers_offset) \ |
| 333 | __ret = -EINVAL; \ |
| 334 | } \ |
| 335 | __ret; \ |
| 336 | }) |
| 337 | |
| 338 | #define EBT_WATCHER_ITERATE(e, fn, args...) \ |
| 339 | ({ \ |
| 340 | unsigned int __i; \ |
| 341 | int __ret = 0; \ |
| 342 | struct ebt_entry_watcher *__watcher; \ |
| 343 | \ |
| 344 | for (__i = e->watchers_offset; \ |
| 345 | __i < (e)->target_offset; \ |
| 346 | __i += __watcher->watcher_size + \ |
| 347 | sizeof(struct ebt_entry_watcher)) { \ |
| 348 | __watcher = (void *)(e) + __i; \ |
| 349 | \ |
| 350 | __ret = fn(__watcher , ## args); \ |
| 351 | if (__ret != 0) \ |
| 352 | break; \ |
| 353 | } \ |
| 354 | if (__ret == 0) { \ |
| 355 | if (__i != (e)->target_offset) \ |
| 356 | __ret = -EINVAL; \ |
| 357 | } \ |
| 358 | __ret; \ |
| 359 | }) |
| 360 | |
| 361 | #define EBT_ENTRY_ITERATE(entries, size, fn, args...) \ |
| 362 | ({ \ |
| 363 | unsigned int __i; \ |
| 364 | int __ret = 0; \ |
| 365 | struct ebt_entry *__entry; \ |
| 366 | \ |
| 367 | for (__i = 0; __i < (size);) { \ |
| 368 | __entry = (void *)(entries) + __i; \ |
| 369 | __ret = fn(__entry , ## args); \ |
| 370 | if (__ret != 0) \ |
| 371 | break; \ |
| 372 | if (__entry->bitmask != 0) \ |
| 373 | __i += __entry->next_offset; \ |
| 374 | else \ |
| 375 | __i += sizeof(struct ebt_entries); \ |
| 376 | } \ |
| 377 | if (__ret == 0) { \ |
| 378 | if (__i != (size)) \ |
| 379 | __ret = -EINVAL; \ |
| 380 | } \ |
| 381 | __ret; \ |
| 382 | }) |
| 383 | |
| 384 | #endif |