![Joerg Willmann](/assets/img/avatar_default.png)
ebt_among extension of ebtables uses __alignof__(_xt_align) while the corresponding kernel module uses __alignof__(ebt_replace) to determine the alignment in EBT_ALIGN(). These are the results of these values on different platforms: x86 x86_64 ppc __alignof__(_xt_align) 4 8 8 __alignof__(ebt_replace) 4 8 4 ebtables fails to add rules which use the among extension. I'm using kernel 2.6.33 and ebtables 2.0.10-4 According to Bart De Schuymer, userspace alignment was changed to _xt_align to fix an alignment issue on a userspace32-kernel64 system (he thinks it was for an ARM device). So userspace must be right. The kernel alignment macro needs to change so it also uses _xt_align instead of ebt_replace. The userspace changes date back from June 29, 2009. Signed-off-by: Joerg Willmann <joe@clnt.de> Signed-off by: Bart De Schuymer <bdschuym@pandora.be> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
381 lines
13 KiB
C
381 lines
13 KiB
C
/*
|
|
* ebtables
|
|
*
|
|
* Authors:
|
|
* Bart De Schuymer <bdschuym@pandora.be>
|
|
*
|
|
* ebtables.c,v 2.0, April, 2002
|
|
*
|
|
* This code is stongly inspired on the iptables code which is
|
|
* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
|
|
*/
|
|
|
|
#ifndef __LINUX_BRIDGE_EFF_H
|
|
#define __LINUX_BRIDGE_EFF_H
|
|
#include <linux/if.h>
|
|
#include <linux/netfilter_bridge.h>
|
|
#include <linux/if_ether.h>
|
|
|
|
#define EBT_TABLE_MAXNAMELEN 32
|
|
#define EBT_CHAIN_MAXNAMELEN EBT_TABLE_MAXNAMELEN
|
|
#define EBT_FUNCTION_MAXNAMELEN EBT_TABLE_MAXNAMELEN
|
|
|
|
/* verdicts >0 are "branches" */
|
|
#define EBT_ACCEPT -1
|
|
#define EBT_DROP -2
|
|
#define EBT_CONTINUE -3
|
|
#define EBT_RETURN -4
|
|
#define NUM_STANDARD_TARGETS 4
|
|
/* ebtables target modules store the verdict inside an int. We can
|
|
* reclaim a part of this int for backwards compatible extensions.
|
|
* The 4 lsb are more than enough to store the verdict. */
|
|
#define EBT_VERDICT_BITS 0x0000000F
|
|
|
|
struct xt_match;
|
|
struct xt_target;
|
|
|
|
struct ebt_counter {
|
|
uint64_t pcnt;
|
|
uint64_t bcnt;
|
|
};
|
|
|
|
struct ebt_replace {
|
|
char name[EBT_TABLE_MAXNAMELEN];
|
|
unsigned int valid_hooks;
|
|
/* nr of rules in the table */
|
|
unsigned int nentries;
|
|
/* total size of the entries */
|
|
unsigned int entries_size;
|
|
/* start of the chains */
|
|
struct ebt_entries __user *hook_entry[NF_BR_NUMHOOKS];
|
|
/* nr of counters userspace expects back */
|
|
unsigned int num_counters;
|
|
/* where the kernel will put the old counters */
|
|
struct ebt_counter __user *counters;
|
|
char __user *entries;
|
|
};
|
|
|
|
struct ebt_replace_kernel {
|
|
char name[EBT_TABLE_MAXNAMELEN];
|
|
unsigned int valid_hooks;
|
|
/* nr of rules in the table */
|
|
unsigned int nentries;
|
|
/* total size of the entries */
|
|
unsigned int entries_size;
|
|
/* start of the chains */
|
|
struct ebt_entries *hook_entry[NF_BR_NUMHOOKS];
|
|
/* nr of counters userspace expects back */
|
|
unsigned int num_counters;
|
|
/* where the kernel will put the old counters */
|
|
struct ebt_counter *counters;
|
|
char *entries;
|
|
};
|
|
|
|
struct ebt_entries {
|
|
/* this field is always set to zero
|
|
* See EBT_ENTRY_OR_ENTRIES.
|
|
* Must be same size as ebt_entry.bitmask */
|
|
unsigned int distinguisher;
|
|
/* the chain name */
|
|
char name[EBT_CHAIN_MAXNAMELEN];
|
|
/* counter offset for this chain */
|
|
unsigned int counter_offset;
|
|
/* one standard (accept, drop, return) per hook */
|
|
int policy;
|
|
/* nr. of entries */
|
|
unsigned int nentries;
|
|
/* entry list */
|
|
char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace))));
|
|
};
|
|
|
|
/* used for the bitmask of struct ebt_entry */
|
|
|
|
/* This is a hack to make a difference between an ebt_entry struct and an
|
|
* ebt_entries struct when traversing the entries from start to end.
|
|
* Using this simplifies the code a lot, while still being able to use
|
|
* ebt_entries.
|
|
* Contrary, iptables doesn't use something like ebt_entries and therefore uses
|
|
* different techniques for naming the policy and such. So, iptables doesn't
|
|
* need a hack like this.
|
|
*/
|
|
#define EBT_ENTRY_OR_ENTRIES 0x01
|
|
/* these are the normal masks */
|
|
#define EBT_NOPROTO 0x02
|
|
#define EBT_802_3 0x04
|
|
#define EBT_SOURCEMAC 0x08
|
|
#define EBT_DESTMAC 0x10
|
|
#define EBT_F_MASK (EBT_NOPROTO | EBT_802_3 | EBT_SOURCEMAC | EBT_DESTMAC \
|
|
| EBT_ENTRY_OR_ENTRIES)
|
|
|
|
#define EBT_IPROTO 0x01
|
|
#define EBT_IIN 0x02
|
|
#define EBT_IOUT 0x04
|
|
#define EBT_ISOURCE 0x8
|
|
#define EBT_IDEST 0x10
|
|
#define EBT_ILOGICALIN 0x20
|
|
#define EBT_ILOGICALOUT 0x40
|
|
#define EBT_INV_MASK (EBT_IPROTO | EBT_IIN | EBT_IOUT | EBT_ILOGICALIN \
|
|
| EBT_ILOGICALOUT | EBT_ISOURCE | EBT_IDEST)
|
|
|
|
struct ebt_entry_match {
|
|
union {
|
|
char name[EBT_FUNCTION_MAXNAMELEN];
|
|
struct xt_match *match;
|
|
} u;
|
|
/* size of data */
|
|
unsigned int match_size;
|
|
unsigned char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace))));
|
|
};
|
|
|
|
struct ebt_entry_watcher {
|
|
union {
|
|
char name[EBT_FUNCTION_MAXNAMELEN];
|
|
struct xt_target *watcher;
|
|
} u;
|
|
/* size of data */
|
|
unsigned int watcher_size;
|
|
unsigned char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace))));
|
|
};
|
|
|
|
struct ebt_entry_target {
|
|
union {
|
|
char name[EBT_FUNCTION_MAXNAMELEN];
|
|
struct xt_target *target;
|
|
} u;
|
|
/* size of data */
|
|
unsigned int target_size;
|
|
unsigned char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace))));
|
|
};
|
|
|
|
#define EBT_STANDARD_TARGET "standard"
|
|
struct ebt_standard_target {
|
|
struct ebt_entry_target target;
|
|
int verdict;
|
|
};
|
|
|
|
/* one entry */
|
|
struct ebt_entry {
|
|
/* this needs to be the first field */
|
|
unsigned int bitmask;
|
|
unsigned int invflags;
|
|
__be16 ethproto;
|
|
/* the physical in-dev */
|
|
char in[IFNAMSIZ];
|
|
/* the logical in-dev */
|
|
char logical_in[IFNAMSIZ];
|
|
/* the physical out-dev */
|
|
char out[IFNAMSIZ];
|
|
/* the logical out-dev */
|
|
char logical_out[IFNAMSIZ];
|
|
unsigned char sourcemac[ETH_ALEN];
|
|
unsigned char sourcemsk[ETH_ALEN];
|
|
unsigned char destmac[ETH_ALEN];
|
|
unsigned char destmsk[ETH_ALEN];
|
|
/* sizeof ebt_entry + matches */
|
|
unsigned int watchers_offset;
|
|
/* sizeof ebt_entry + matches + watchers */
|
|
unsigned int target_offset;
|
|
/* sizeof ebt_entry + matches + watchers + target */
|
|
unsigned int next_offset;
|
|
unsigned char elems[0] __attribute__ ((aligned (__alignof__(struct ebt_replace))));
|
|
};
|
|
|
|
/* {g,s}etsockopt numbers */
|
|
#define EBT_BASE_CTL 128
|
|
|
|
#define EBT_SO_SET_ENTRIES (EBT_BASE_CTL)
|
|
#define EBT_SO_SET_COUNTERS (EBT_SO_SET_ENTRIES+1)
|
|
#define EBT_SO_SET_MAX (EBT_SO_SET_COUNTERS+1)
|
|
|
|
#define EBT_SO_GET_INFO (EBT_BASE_CTL)
|
|
#define EBT_SO_GET_ENTRIES (EBT_SO_GET_INFO+1)
|
|
#define EBT_SO_GET_INIT_INFO (EBT_SO_GET_ENTRIES+1)
|
|
#define EBT_SO_GET_INIT_ENTRIES (EBT_SO_GET_INIT_INFO+1)
|
|
#define EBT_SO_GET_MAX (EBT_SO_GET_INIT_ENTRIES+1)
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
/* return values for match() functions */
|
|
#define EBT_MATCH 0
|
|
#define EBT_NOMATCH 1
|
|
|
|
struct ebt_match {
|
|
struct list_head list;
|
|
const char name[EBT_FUNCTION_MAXNAMELEN];
|
|
bool (*match)(const struct sk_buff *skb, const struct net_device *in,
|
|
const struct net_device *out, const struct xt_match *match,
|
|
const void *matchinfo, int offset, unsigned int protoff,
|
|
bool *hotdrop);
|
|
bool (*checkentry)(const char *table, const void *entry,
|
|
const struct xt_match *match, void *matchinfo,
|
|
unsigned int hook_mask);
|
|
void (*destroy)(const struct xt_match *match, void *matchinfo);
|
|
unsigned int matchsize;
|
|
u_int8_t revision;
|
|
u_int8_t family;
|
|
struct module *me;
|
|
};
|
|
|
|
struct ebt_watcher {
|
|
struct list_head list;
|
|
const char name[EBT_FUNCTION_MAXNAMELEN];
|
|
unsigned int (*target)(struct sk_buff *skb,
|
|
const struct net_device *in, const struct net_device *out,
|
|
unsigned int hook_num, const struct xt_target *target,
|
|
const void *targinfo);
|
|
bool (*checkentry)(const char *table, const void *entry,
|
|
const struct xt_target *target, void *targinfo,
|
|
unsigned int hook_mask);
|
|
void (*destroy)(const struct xt_target *target, void *targinfo);
|
|
unsigned int targetsize;
|
|
u_int8_t revision;
|
|
u_int8_t family;
|
|
struct module *me;
|
|
};
|
|
|
|
struct ebt_target {
|
|
struct list_head list;
|
|
const char name[EBT_FUNCTION_MAXNAMELEN];
|
|
/* returns one of the standard EBT_* verdicts */
|
|
unsigned int (*target)(struct sk_buff *skb,
|
|
const struct net_device *in, const struct net_device *out,
|
|
unsigned int hook_num, const struct xt_target *target,
|
|
const void *targinfo);
|
|
bool (*checkentry)(const char *table, const void *entry,
|
|
const struct xt_target *target, void *targinfo,
|
|
unsigned int hook_mask);
|
|
void (*destroy)(const struct xt_target *target, void *targinfo);
|
|
unsigned int targetsize;
|
|
u_int8_t revision;
|
|
u_int8_t family;
|
|
struct module *me;
|
|
};
|
|
|
|
/* used for jumping from and into user defined chains (udc) */
|
|
struct ebt_chainstack {
|
|
struct ebt_entries *chaininfo; /* pointer to chain data */
|
|
struct ebt_entry *e; /* pointer to entry data */
|
|
unsigned int n; /* n'th entry */
|
|
};
|
|
|
|
struct ebt_table_info {
|
|
/* total size of the entries */
|
|
unsigned int entries_size;
|
|
unsigned int nentries;
|
|
/* pointers to the start of the chains */
|
|
struct ebt_entries *hook_entry[NF_BR_NUMHOOKS];
|
|
/* room to maintain the stack used for jumping from and into udc */
|
|
struct ebt_chainstack **chainstack;
|
|
char *entries;
|
|
struct ebt_counter counters[0] ____cacheline_aligned;
|
|
};
|
|
|
|
struct ebt_table {
|
|
struct list_head list;
|
|
char name[EBT_TABLE_MAXNAMELEN];
|
|
struct ebt_replace_kernel *table;
|
|
unsigned int valid_hooks;
|
|
rwlock_t lock;
|
|
/* e.g. could be the table explicitly only allows certain
|
|
* matches, targets, ... 0 == let it in */
|
|
int (*check)(const struct ebt_table_info *info,
|
|
unsigned int valid_hooks);
|
|
/* the data used by the kernel */
|
|
struct ebt_table_info *private;
|
|
struct module *me;
|
|
};
|
|
|
|
#define EBT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1)) & \
|
|
~(__alignof__(struct _xt_align)-1))
|
|
extern struct ebt_table *ebt_register_table(struct net *net,
|
|
const struct ebt_table *table);
|
|
extern void ebt_unregister_table(struct net *net, struct ebt_table *table);
|
|
extern unsigned int ebt_do_table(unsigned int hook, struct sk_buff *skb,
|
|
const struct net_device *in, const struct net_device *out,
|
|
struct ebt_table *table);
|
|
|
|
/* Used in the kernel match() functions */
|
|
#define FWINV(bool,invflg) ((bool) ^ !!(info->invflags & invflg))
|
|
/* True if the hook mask denotes that the rule is in a base chain,
|
|
* used in the check() functions */
|
|
#define BASE_CHAIN (par->hook_mask & (1 << NF_BR_NUMHOOKS))
|
|
/* Clear the bit in the hook mask that tells if the rule is on a base chain */
|
|
#define CLEAR_BASE_CHAIN_BIT (par->hook_mask &= ~(1 << NF_BR_NUMHOOKS))
|
|
/* True if the target is not a standard target */
|
|
#define INVALID_TARGET (info->target < -NUM_STANDARD_TARGETS || info->target >= 0)
|
|
|
|
#endif /* __KERNEL__ */
|
|
|
|
/* blatently stolen from ip_tables.h
|
|
* fn returns 0 to continue iteration */
|
|
#define EBT_MATCH_ITERATE(e, fn, args...) \
|
|
({ \
|
|
unsigned int __i; \
|
|
int __ret = 0; \
|
|
struct ebt_entry_match *__match; \
|
|
\
|
|
for (__i = sizeof(struct ebt_entry); \
|
|
__i < (e)->watchers_offset; \
|
|
__i += __match->match_size + \
|
|
sizeof(struct ebt_entry_match)) { \
|
|
__match = (void *)(e) + __i; \
|
|
\
|
|
__ret = fn(__match , ## args); \
|
|
if (__ret != 0) \
|
|
break; \
|
|
} \
|
|
if (__ret == 0) { \
|
|
if (__i != (e)->watchers_offset) \
|
|
__ret = -EINVAL; \
|
|
} \
|
|
__ret; \
|
|
})
|
|
|
|
#define EBT_WATCHER_ITERATE(e, fn, args...) \
|
|
({ \
|
|
unsigned int __i; \
|
|
int __ret = 0; \
|
|
struct ebt_entry_watcher *__watcher; \
|
|
\
|
|
for (__i = e->watchers_offset; \
|
|
__i < (e)->target_offset; \
|
|
__i += __watcher->watcher_size + \
|
|
sizeof(struct ebt_entry_watcher)) { \
|
|
__watcher = (void *)(e) + __i; \
|
|
\
|
|
__ret = fn(__watcher , ## args); \
|
|
if (__ret != 0) \
|
|
break; \
|
|
} \
|
|
if (__ret == 0) { \
|
|
if (__i != (e)->target_offset) \
|
|
__ret = -EINVAL; \
|
|
} \
|
|
__ret; \
|
|
})
|
|
|
|
#define EBT_ENTRY_ITERATE(entries, size, fn, args...) \
|
|
({ \
|
|
unsigned int __i; \
|
|
int __ret = 0; \
|
|
struct ebt_entry *__entry; \
|
|
\
|
|
for (__i = 0; __i < (size);) { \
|
|
__entry = (void *)(entries) + __i; \
|
|
__ret = fn(__entry , ## args); \
|
|
if (__ret != 0) \
|
|
break; \
|
|
if (__entry->bitmask != 0) \
|
|
__i += __entry->next_offset; \
|
|
else \
|
|
__i += sizeof(struct ebt_entries); \
|
|
} \
|
|
if (__ret == 0) { \
|
|
if (__i != (size)) \
|
|
__ret = -EINVAL; \
|
|
} \
|
|
__ret; \
|
|
})
|
|
|
|
#endif
|