diff options
Diffstat (limited to 'include/linux/netfilter/x_tables.h')
| -rw-r--r-- | include/linux/netfilter/x_tables.h | 622 |
1 files changed, 622 insertions, 0 deletions
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h new file mode 100644 index 00000000..32cddf78 --- /dev/null +++ b/include/linux/netfilter/x_tables.h @@ -0,0 +1,622 @@ +#ifndef _X_TABLES_H +#define _X_TABLES_H +#include <linux/kernel.h> +#include <linux/types.h> + +#define XT_FUNCTION_MAXNAMELEN 30 +#define XT_EXTENSION_MAXNAMELEN 29 +#define XT_TABLE_MAXNAMELEN 32 + +struct xt_entry_match { + union { + struct { + __u16 match_size; + + /* Used by userspace */ + char name[XT_EXTENSION_MAXNAMELEN]; + __u8 revision; + } user; + struct { + __u16 match_size; + + /* Used inside the kernel */ + struct xt_match *match; + } kernel; + + /* Total length */ + __u16 match_size; + } u; + + unsigned char data[0]; +}; + +struct xt_entry_target { + union { + struct { + __u16 target_size; + + /* Used by userspace */ + char name[XT_EXTENSION_MAXNAMELEN]; + __u8 revision; + } user; + struct { + __u16 target_size; + + /* Used inside the kernel */ + struct xt_target *target; + } kernel; + + /* Total length */ + __u16 target_size; + } u; + + unsigned char data[0]; +}; + +#define XT_TARGET_INIT(__name, __size) \ +{ \ + .target.u.user = { \ + .target_size = XT_ALIGN(__size), \ + .name = __name, \ + }, \ +} + +struct xt_standard_target { + struct xt_entry_target target; + int verdict; +}; + +struct xt_error_target { + struct xt_entry_target target; + char errorname[XT_FUNCTION_MAXNAMELEN]; +}; + +/* The argument to IPT_SO_GET_REVISION_*. Returns highest revision + * kernel supports, if >= revision. */ +struct xt_get_revision { + char name[XT_EXTENSION_MAXNAMELEN]; + __u8 revision; +}; + +/* CONTINUE verdict for targets */ +#define XT_CONTINUE 0xFFFFFFFF + +/* For standard target */ +#define XT_RETURN (-NF_REPEAT - 1) + +/* this is a dummy structure to find out the alignment requirement for a struct + * containing all the fundamental data types that are used in ipt_entry, + * ip6t_entry and arpt_entry. This sucks, and it is a hack. It will be my + * personal pleasure to remove it -HW + */ +struct _xt_align { + __u8 u8; + __u16 u16; + __u32 u32; + __u64 u64; +}; + +#define XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _xt_align)) + +/* Standard return verdict, or do jump. */ +#define XT_STANDARD_TARGET "" +/* Error verdict. */ +#define XT_ERROR_TARGET "ERROR" + +#define SET_COUNTER(c,b,p) do { (c).bcnt = (b); (c).pcnt = (p); } while(0) +#define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0) + +struct xt_counters { + __u64 pcnt, bcnt; /* Packet and byte counters */ +}; + +/* The argument to IPT_SO_ADD_COUNTERS. */ +struct xt_counters_info { + /* Which table. */ + char name[XT_TABLE_MAXNAMELEN]; + + unsigned int num_counters; + + /* The counters (actually `number' of these). */ + struct xt_counters counters[0]; +}; + +#define XT_INV_PROTO 0x40 /* Invert the sense of PROTO. */ + +#ifndef __KERNEL__ +/* fn returns 0 to continue iteration */ +#define XT_MATCH_ITERATE(type, e, fn, args...) \ +({ \ + unsigned int __i; \ + int __ret = 0; \ + struct xt_entry_match *__m; \ + \ + for (__i = sizeof(type); \ + __i < (e)->target_offset; \ + __i += __m->u.match_size) { \ + __m = (void *)e + __i; \ + \ + __ret = fn(__m , ## args); \ + if (__ret != 0) \ + break; \ + } \ + __ret; \ +}) + +/* fn returns 0 to continue iteration */ +#define XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \ +({ \ + unsigned int __i, __n; \ + int __ret = 0; \ + type *__entry; \ + \ + for (__i = 0, __n = 0; __i < (size); \ + __i += __entry->next_offset, __n++) { \ + __entry = (void *)(entries) + __i; \ + if (__n < n) \ + continue; \ + \ + __ret = fn(__entry , ## args); \ + if (__ret != 0) \ + break; \ + } \ + __ret; \ +}) + +/* fn returns 0 to continue iteration */ +#define XT_ENTRY_ITERATE(type, entries, size, fn, args...) \ + XT_ENTRY_ITERATE_CONTINUE(type, entries, size, 0, fn, args) + +#endif /* !__KERNEL__ */ + +/* pos is normally a struct ipt_entry/ip6t_entry/etc. */ +#define xt_entry_foreach(pos, ehead, esize) \ + for ((pos) = (typeof(pos))(ehead); \ + (pos) < (typeof(pos))((char *)(ehead) + (esize)); \ + (pos) = (typeof(pos))((char *)(pos) + (pos)->next_offset)) + +/* can only be xt_entry_match, so no use of typeof here */ +#define xt_ematch_foreach(pos, entry) \ + for ((pos) = (struct xt_entry_match *)entry->elems; \ + (pos) < (struct xt_entry_match *)((char *)(entry) + \ + (entry)->target_offset); \ + (pos) = (struct xt_entry_match *)((char *)(pos) + \ + (pos)->u.match_size)) + +#ifdef __KERNEL__ + +#include <linux/netdevice.h> + +/** + * struct xt_action_param - parameters for matches/targets + * + * @match: the match extension + * @target: the target extension + * @matchinfo: per-match data + * @targetinfo: per-target data + * @in: input netdevice + * @out: output netdevice + * @fragoff: packet is a fragment, this is the data offset + * @thoff: position of transport header relative to skb->data + * @hook: hook number given packet came from + * @family: Actual NFPROTO_* through which the function is invoked + * (helpful when match->family == NFPROTO_UNSPEC) + * + * Fields written to by extensions: + * + * @hotdrop: drop packet if we had inspection problems + * Network namespace obtainable using dev_net(in/out) + */ +struct xt_action_param { + union { + const struct xt_match *match; + const struct xt_target *target; + }; + union { + const void *matchinfo, *targinfo; + }; + const struct net_device *in, *out; + int fragoff; + unsigned int thoff; + unsigned int hooknum; + u_int8_t family; + bool hotdrop; +}; + +/** + * struct xt_mtchk_param - parameters for match extensions' + * checkentry functions + * + * @net: network namespace through which the check was invoked + * @table: table the rule is tried to be inserted into + * @entryinfo: the family-specific rule data + * (struct ipt_ip, ip6t_ip, arpt_arp or (note) ebt_entry) + * @match: struct xt_match through which this function was invoked + * @matchinfo: per-match data + * @hook_mask: via which hooks the new rule is reachable + * Other fields as above. + */ +struct xt_mtchk_param { + struct net *net; + const char *table; + const void *entryinfo; + const struct xt_match *match; + void *matchinfo; + unsigned int hook_mask; + u_int8_t family; +}; + +/** + * struct xt_mdtor_param - match destructor parameters + * Fields as above. + */ +struct xt_mtdtor_param { + struct net *net; + const struct xt_match *match; + void *matchinfo; + u_int8_t family; +}; + +/** + * struct xt_tgchk_param - parameters for target extensions' + * checkentry functions + * + * @entryinfo: the family-specific rule data + * (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry) + * + * Other fields see above. + */ +struct xt_tgchk_param { + struct net *net; + const char *table; + const void *entryinfo; + const struct xt_target *target; + void *targinfo; + unsigned int hook_mask; + u_int8_t family; +}; + +/* Target destructor parameters */ +struct xt_tgdtor_param { + struct net *net; + const struct xt_target *target; + void *targinfo; + u_int8_t family; +}; + +struct xt_match { + struct list_head list; + + const char name[XT_EXTENSION_MAXNAMELEN]; + u_int8_t revision; + + /* Return true or false: return FALSE and set *hotdrop = 1 to + force immediate packet drop. */ + /* Arguments changed since 2.6.9, as this must now handle + non-linear skb, using skb_header_pointer and + skb_ip_make_writable. */ + bool (*match)(const struct sk_buff *skb, + struct xt_action_param *); + + /* Called when user tries to insert an entry of this type. */ + int (*checkentry)(const struct xt_mtchk_param *); + + /* Called when entry of this type deleted. */ + void (*destroy)(const struct xt_mtdtor_param *); +#ifdef CONFIG_COMPAT + /* Called when userspace align differs from kernel space one */ + void (*compat_from_user)(void *dst, const void *src); + int (*compat_to_user)(void __user *dst, const void *src); +#endif + /* Set this to THIS_MODULE if you are a module, otherwise NULL */ + struct module *me; + + const char *table; + unsigned int matchsize; +#ifdef CONFIG_COMPAT + unsigned int compatsize; +#endif + unsigned int hooks; + unsigned short proto; + + unsigned short family; +}; + +/* Registration hooks for targets. */ +struct xt_target { + struct list_head list; + + const char name[XT_EXTENSION_MAXNAMELEN]; + u_int8_t revision; + + /* Returns verdict. Argument order changed since 2.6.9, as this + must now handle non-linear skbs, using skb_copy_bits and + skb_ip_make_writable. */ + unsigned int (*target)(struct sk_buff *skb, + const struct xt_action_param *); + + /* Called when user tries to insert an entry of this type: + hook_mask is a bitmask of hooks from which it can be + called. */ + /* Should return 0 on success or an error code otherwise (-Exxxx). */ + int (*checkentry)(const struct xt_tgchk_param *); + + /* Called when entry of this type deleted. */ + void (*destroy)(const struct xt_tgdtor_param *); +#ifdef CONFIG_COMPAT + /* Called when userspace align differs from kernel space one */ + void (*compat_from_user)(void *dst, const void *src); + int (*compat_to_user)(void __user *dst, const void *src); +#endif + /* Set this to THIS_MODULE if you are a module, otherwise NULL */ + struct module *me; + + const char *table; + unsigned int targetsize; +#ifdef CONFIG_COMPAT + unsigned int compatsize; +#endif + unsigned int hooks; + unsigned short proto; + + unsigned short family; +}; + +/* Furniture shopping... */ +struct xt_table { + struct list_head list; + + /* What hooks you will enter on */ + unsigned int valid_hooks; + + /* Man behind the curtain... */ + struct xt_table_info *private; + + /* Set this to THIS_MODULE if you are a module, otherwise NULL */ + struct module *me; + + u_int8_t af; /* address/protocol family */ + int priority; /* hook order */ + + /* A unique name... */ + const char name[XT_TABLE_MAXNAMELEN]; +}; + +#include <linux/netfilter_ipv4.h> + +/* The table itself */ +struct xt_table_info { + /* Size per table */ + unsigned int size; + /* Number of entries: FIXME. --RR */ + unsigned int number; + /* Initial number of entries. Needed for module usage count */ + unsigned int initial_entries; + + /* Entry points and underflows */ + unsigned int hook_entry[NF_INET_NUMHOOKS]; + unsigned int underflow[NF_INET_NUMHOOKS]; + + /* + * Number of user chains. Since tables cannot have loops, at most + * @stacksize jumps (number of user chains) can possibly be made. + */ + unsigned int stacksize; + unsigned int __percpu *stackptr; + void ***jumpstack; + /* ipt_entry tables: one per CPU */ + /* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */ + void *entries[1]; +}; + +#define XT_TABLE_INFO_SZ (offsetof(struct xt_table_info, entries) \ + + nr_cpu_ids * sizeof(char *)) +extern int xt_register_target(struct xt_target *target); +extern void xt_unregister_target(struct xt_target *target); +extern int xt_register_targets(struct xt_target *target, unsigned int n); +extern void xt_unregister_targets(struct xt_target *target, unsigned int n); + +extern int xt_register_match(struct xt_match *target); +extern void xt_unregister_match(struct xt_match *target); +extern int xt_register_matches(struct xt_match *match, unsigned int n); +extern void xt_unregister_matches(struct xt_match *match, unsigned int n); + +extern int xt_check_match(struct xt_mtchk_param *, + unsigned int size, u_int8_t proto, bool inv_proto); +extern int xt_check_target(struct xt_tgchk_param *, + unsigned int size, u_int8_t proto, bool inv_proto); + +extern struct xt_table *xt_register_table(struct net *net, + const struct xt_table *table, + struct xt_table_info *bootstrap, + struct xt_table_info *newinfo); +extern void *xt_unregister_table(struct xt_table *table); + +extern struct xt_table_info *xt_replace_table(struct xt_table *table, + unsigned int num_counters, + struct xt_table_info *newinfo, + int *error); + +extern struct xt_match *xt_find_match(u8 af, const char *name, u8 revision); +extern struct xt_target *xt_find_target(u8 af, const char *name, u8 revision); +extern struct xt_match *xt_request_find_match(u8 af, const char *name, + u8 revision); +extern struct xt_target *xt_request_find_target(u8 af, const char *name, + u8 revision); +extern int xt_find_revision(u8 af, const char *name, u8 revision, + int target, int *err); + +extern struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af, + const char *name); +extern void xt_table_unlock(struct xt_table *t); + +extern int xt_proto_init(struct net *net, u_int8_t af); +extern void xt_proto_fini(struct net *net, u_int8_t af); + +extern struct xt_table_info *xt_alloc_table_info(unsigned int size); +extern void xt_free_table_info(struct xt_table_info *info); + +/** + * xt_recseq - recursive seqcount for netfilter use + * + * Packet processing changes the seqcount only if no recursion happened + * get_counters() can use read_seqcount_begin()/read_seqcount_retry(), + * because we use the normal seqcount convention : + * Low order bit set to 1 if a writer is active. + */ +DECLARE_PER_CPU(seqcount_t, xt_recseq); + +/** + * xt_write_recseq_begin - start of a write section + * + * Begin packet processing : all readers must wait the end + * 1) Must be called with preemption disabled + * 2) softirqs must be disabled too (or we should use irqsafe_cpu_add()) + * Returns : + * 1 if no recursion on this cpu + * 0 if recursion detected + */ +static inline unsigned int xt_write_recseq_begin(void) +{ + unsigned int addend; + + /* + * Low order bit of sequence is set if we already + * called xt_write_recseq_begin(). + */ + addend = (__this_cpu_read(xt_recseq.sequence) + 1) & 1; + + /* + * This is kind of a write_seqcount_begin(), but addend is 0 or 1 + * We dont check addend value to avoid a test and conditional jump, + * since addend is most likely 1 + */ + __this_cpu_add(xt_recseq.sequence, addend); + smp_wmb(); + + return addend; +} + +/** + * xt_write_recseq_end - end of a write section + * @addend: return value from previous xt_write_recseq_begin() + * + * End packet processing : all readers can proceed + * 1) Must be called with preemption disabled + * 2) softirqs must be disabled too (or we should use irqsafe_cpu_add()) + */ +static inline void xt_write_recseq_end(unsigned int addend) +{ + /* this is kind of a write_seqcount_end(), but addend is 0 or 1 */ + smp_wmb(); + __this_cpu_add(xt_recseq.sequence, addend); +} + +/* + * This helper is performance critical and must be inlined + */ +static inline unsigned long ifname_compare_aligned(const char *_a, + const char *_b, + const char *_mask) +{ + const unsigned long *a = (const unsigned long *)_a; + const unsigned long *b = (const unsigned long *)_b; + const unsigned long *mask = (const unsigned long *)_mask; + unsigned long ret; + + ret = (a[0] ^ b[0]) & mask[0]; + if (IFNAMSIZ > sizeof(unsigned long)) + ret |= (a[1] ^ b[1]) & mask[1]; + if (IFNAMSIZ > 2 * sizeof(unsigned long)) + ret |= (a[2] ^ b[2]) & mask[2]; + if (IFNAMSIZ > 3 * sizeof(unsigned long)) + ret |= (a[3] ^ b[3]) & mask[3]; + BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long)); + return ret; +} + +extern struct nf_hook_ops *xt_hook_link(const struct xt_table *, nf_hookfn *); +extern void xt_hook_unlink(const struct xt_table *, struct nf_hook_ops *); + +#ifdef CONFIG_COMPAT +#include <net/compat.h> + +struct compat_xt_entry_match { + union { + struct { + u_int16_t match_size; + char name[XT_FUNCTION_MAXNAMELEN - 1]; + u_int8_t revision; + } user; + struct { + u_int16_t match_size; + compat_uptr_t match; + } kernel; + u_int16_t match_size; + } u; + unsigned char data[0]; +}; + +struct compat_xt_entry_target { + union { + struct { + u_int16_t target_size; + char name[XT_FUNCTION_MAXNAMELEN - 1]; + u_int8_t revision; + } user; + struct { + u_int16_t target_size; + compat_uptr_t target; + } kernel; + u_int16_t target_size; + } u; + unsigned char data[0]; +}; + +/* FIXME: this works only on 32 bit tasks + * need to change whole approach in order to calculate align as function of + * current task alignment */ + +struct compat_xt_counters { + compat_u64 pcnt, bcnt; /* Packet and byte counters */ +}; + +struct compat_xt_counters_info { + char name[XT_TABLE_MAXNAMELEN]; + compat_uint_t num_counters; + struct compat_xt_counters counters[0]; +}; + +struct _compat_xt_align { + __u8 u8; + __u16 u16; + __u32 u32; + compat_u64 u64; +}; + +#define COMPAT_XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _compat_xt_align)) + +extern void xt_compat_lock(u_int8_t af); +extern void xt_compat_unlock(u_int8_t af); + +extern int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta); +extern void xt_compat_flush_offsets(u_int8_t af); +extern void xt_compat_init_offsets(u_int8_t af, unsigned int number); +extern int xt_compat_calc_jump(u_int8_t af, unsigned int offset); + +extern int xt_compat_match_offset(const struct xt_match *match); +extern int xt_compat_match_from_user(struct xt_entry_match *m, + void **dstptr, unsigned int *size); +extern int xt_compat_match_to_user(const struct xt_entry_match *m, + void __user **dstptr, unsigned int *size); + +extern int xt_compat_target_offset(const struct xt_target *target); +extern void xt_compat_target_from_user(struct xt_entry_target *t, + void **dstptr, unsigned int *size); +extern int xt_compat_target_to_user(const struct xt_entry_target *t, + void __user **dstptr, unsigned int *size); + +#endif /* CONFIG_COMPAT */ +#endif /* __KERNEL__ */ + +#endif /* _X_TABLES_H */ |