Home | History | Annotate | Download | only in netfilter_bridge
      1 /*
      2  *  ebtables
      3  *
      4  *	Authors:
      5  *	Bart De Schuymer		<bdschuym (at) 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 _UAPI__LINUX_BRIDGE_EFF_H
     14 #define _UAPI__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 
     34 struct xt_match;
     35 struct xt_target;
     36 
     37 struct ebt_counter {
     38 	uint64_t pcnt;
     39 	uint64_t bcnt;
     40 };
     41 
     42 struct 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 
     58 struct 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 
     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 a lot, 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 	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 
    130 struct 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 
    140 struct 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"
    151 struct ebt_standard_target {
    152 	struct ebt_entry_target target;
    153 	int verdict;
    154 };
    155 
    156 /* one entry */
    157 struct 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 
    197 /* blatently stolen from ip_tables.h
    198  * fn returns 0 to continue iteration */
    199 #define EBT_MATCH_ITERATE(e, fn, args...)                   \
    200 ({                                                          \
    201 	unsigned int __i;                                   \
    202 	int __ret = 0;                                      \
    203 	struct ebt_entry_match *__match;                    \
    204 	                                                    \
    205 	for (__i = sizeof(struct ebt_entry);                \
    206 	     __i < (e)->watchers_offset;                    \
    207 	     __i += __match->match_size +                   \
    208 	     sizeof(struct ebt_entry_match)) {              \
    209 		__match = (void *)(e) + __i;                \
    210 		                                            \
    211 		__ret = fn(__match , ## args);              \
    212 		if (__ret != 0)                             \
    213 			break;                              \
    214 	}                                                   \
    215 	if (__ret == 0) {                                   \
    216 		if (__i != (e)->watchers_offset)            \
    217 			__ret = -EINVAL;                    \
    218 	}                                                   \
    219 	__ret;                                              \
    220 })
    221 
    222 #define EBT_WATCHER_ITERATE(e, fn, args...)                 \
    223 ({                                                          \
    224 	unsigned int __i;                                   \
    225 	int __ret = 0;                                      \
    226 	struct ebt_entry_watcher *__watcher;                \
    227 	                                                    \
    228 	for (__i = e->watchers_offset;                      \
    229 	     __i < (e)->target_offset;                      \
    230 	     __i += __watcher->watcher_size +               \
    231 	     sizeof(struct ebt_entry_watcher)) {            \
    232 		__watcher = (void *)(e) + __i;              \
    233 		                                            \
    234 		__ret = fn(__watcher , ## args);            \
    235 		if (__ret != 0)                             \
    236 			break;                              \
    237 	}                                                   \
    238 	if (__ret == 0) {                                   \
    239 		if (__i != (e)->target_offset)              \
    240 			__ret = -EINVAL;                    \
    241 	}                                                   \
    242 	__ret;                                              \
    243 })
    244 
    245 #define EBT_ENTRY_ITERATE(entries, size, fn, args...)       \
    246 ({                                                          \
    247 	unsigned int __i;                                   \
    248 	int __ret = 0;                                      \
    249 	struct ebt_entry *__entry;                          \
    250 	                                                    \
    251 	for (__i = 0; __i < (size);) {                      \
    252 		__entry = (void *)(entries) + __i;          \
    253 		__ret = fn(__entry , ## args);              \
    254 		if (__ret != 0)                             \
    255 			break;                              \
    256 		if (__entry->bitmask != 0)                  \
    257 			__i += __entry->next_offset;        \
    258 		else                                        \
    259 			__i += sizeof(struct ebt_entries);  \
    260 	}                                                   \
    261 	if (__ret == 0) {                                   \
    262 		if (__i != (size))                          \
    263 			__ret = -EINVAL;                    \
    264 	}                                                   \
    265 	__ret;                                              \
    266 })
    267 
    268 #endif /* _UAPI__LINUX_BRIDGE_EFF_H */
    269