[linux-2.6-block.git] / include / linux / filter.h

/*
 * Linux Socket Filter Data Structures
 */

#ifndef __LINUX_FILTER_H__
#define __LINUX_FILTER_H__

#include <linux/compiler.h>
#include <linux/types.h>

#ifdef __KERNEL__
#include <asm/atomic.h>
#endif

/*
 * Current version of the filter code architecture.
 */
#define BPF_MAJOR_VERSION 1
#define BPF_MINOR_VERSION 1

/*
 *	Try and keep these values and structures similar to BSD, especially
 *	the BPF code definitions which need to match so you can share filters
 */
 
struct sock_filter	/* Filter block */
{
        __u16	code;   /* Actual filter code */
        __u8	jt;	/* Jump true */
        __u8	jf;	/* Jump false */
        __u32	k;      /* Generic multiuse field */
};

struct sock_fprog	/* Required for SO_ATTACH_FILTER. */
{
	unsigned short		len;	/* Number of filter blocks */
	struct sock_filter __user *filter;
};

#ifdef __KERNEL__
struct sk_filter
{
	atomic_t		refcnt;
        unsigned int         	len;	/* Number of filter blocks */
        struct sock_filter     	insns[0];
};

static inline unsigned int sk_filter_len(struct sk_filter *fp)
{
	return fp->len*sizeof(struct sock_filter) + sizeof(*fp);
}
#endif

/*
 * Instruction classes
 */

#define BPF_CLASS(code) ((code) & 0x07)
#define         BPF_LD          0x00
#define         BPF_LDX         0x01
#define         BPF_ST          0x02
#define         BPF_STX         0x03
#define         BPF_ALU         0x04
#define         BPF_JMP         0x05
#define         BPF_RET         0x06
#define         BPF_MISC        0x07

/* ld/ldx fields */
#define BPF_SIZE(code)  ((code) & 0x18)
#define         BPF_W           0x00
#define         BPF_H           0x08
#define         BPF_B           0x10
#define BPF_MODE(code)  ((code) & 0xe0)
#define         BPF_IMM         0x00
#define         BPF_ABS         0x20
#define         BPF_IND         0x40
#define         BPF_MEM         0x60
#define         BPF_LEN         0x80
#define         BPF_MSH         0xa0

/* alu/jmp fields */
#define BPF_OP(code)    ((code) & 0xf0)
#define         BPF_ADD         0x00
#define         BPF_SUB         0x10
#define         BPF_MUL         0x20
#define         BPF_DIV         0x30
#define         BPF_OR          0x40
#define         BPF_AND         0x50
#define         BPF_LSH         0x60
#define         BPF_RSH         0x70
#define         BPF_NEG         0x80
#define         BPF_JA          0x00
#define         BPF_JEQ         0x10
#define         BPF_JGT         0x20
#define         BPF_JGE         0x30
#define         BPF_JSET        0x40
#define BPF_SRC(code)   ((code) & 0x08)
#define         BPF_K           0x00
#define         BPF_X           0x08

/* ret - BPF_K and BPF_X also apply */
#define BPF_RVAL(code)  ((code) & 0x18)
#define         BPF_A           0x10

/* misc */
#define BPF_MISCOP(code) ((code) & 0xf8)
#define         BPF_TAX         0x00
#define         BPF_TXA         0x80

#ifndef BPF_MAXINSNS
#define BPF_MAXINSNS 4096
#endif

/*
 * Macros for filter block array initializers.
 */
#ifndef BPF_STMT
#define BPF_STMT(code, k) { (unsigned short)(code), 0, 0, k }
#endif
#ifndef BPF_JUMP
#define BPF_JUMP(code, k, jt, jf) { (unsigned short)(code), jt, jf, k }
#endif

/*
 * Number of scratch memory words for: BPF_ST and BPF_STX
 */
#define BPF_MEMWORDS 16

/* RATIONALE. Negative offsets are invalid in BPF.
   We use them to reference ancillary data.
   Unlike introduction new instructions, it does not break
   existing compilers/optimizers.
 */
#define SKF_AD_OFF    (-0x1000)
#define SKF_AD_PROTOCOL 0
#define SKF_AD_PKTTYPE 	4
#define SKF_AD_IFINDEX 	8
#define SKF_AD_MAX 	12
#define SKF_NET_OFF   (-0x100000)
#define SKF_LL_OFF    (-0x200000)

#ifdef __KERNEL__
struct sk_buff;
struct sock;

extern int sk_run_filter(struct sk_buff *skb, struct sock_filter *filter, int flen);
extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
extern int sk_chk_filter(struct sock_filter *filter, int flen);
#endif /* __KERNEL__ */

#endif /* __LINUX_FILTER_H__ */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Linux Socket Filter Data Structures
	3	*/
	4
	5	#ifndef __LINUX_FILTER_H__
	6	#define __LINUX_FILTER_H__
	7
	8	#include <linux/compiler.h>
	9	#include <linux/types.h>
	10
	11	#ifdef __KERNEL__
	12	#include <asm/atomic.h>
	13	#endif
	14
	15	/*
	16	* Current version of the filter code architecture.
	17	*/
	18	#define BPF_MAJOR_VERSION 1
	19	#define BPF_MINOR_VERSION 1
	20
	21	/*
	22	* Try and keep these values and structures similar to BSD, especially
	23	* the BPF code definitions which need to match so you can share filters
	24	*/
	25
	26	struct sock_filter /* Filter block */
	27	{
	28	__u16 code; /* Actual filter code */
	29	__u8 jt; /* Jump true */
	30	__u8 jf; /* Jump false */
	31	__u32 k; /* Generic multiuse field */
	32	};
	33
	34	struct sock_fprog /* Required for SO_ATTACH_FILTER. */
	35	{
	36	unsigned short len; /* Number of filter blocks */
	37	struct sock_filter __user *filter;
	38	};
	39
	40	#ifdef __KERNEL__
	41	struct sk_filter
	42	{
	43	atomic_t refcnt;
	44	unsigned int len; /* Number of filter blocks */
	45	struct sock_filter insns[0];
	46	};
	47
	48	static inline unsigned int sk_filter_len(struct sk_filter *fp)
	49	{
	50	return fp->lensizeof(struct sock_filter) + sizeof(fp);
	51	}
	52	#endif
	53
	54	/*
	55	* Instruction classes
	56	*/
	57
	58	#define BPF_CLASS(code) ((code) & 0x07)
	59	#define BPF_LD 0x00
	60	#define BPF_LDX 0x01
	61	#define BPF_ST 0x02
	62	#define BPF_STX 0x03
	63	#define BPF_ALU 0x04
	64	#define BPF_JMP 0x05
65	#define BPF_RET 0x06
66	#define BPF_MISC 0x07
67
68	/* ld/ldx fields */
69	#define BPF_SIZE(code) ((code) & 0x18)
70	#define BPF_W 0x00
71	#define BPF_H 0x08
72	#define BPF_B 0x10
73	#define BPF_MODE(code) ((code) & 0xe0)
74	#define BPF_IMM 0x00
75	#define BPF_ABS 0x20
76	#define BPF_IND 0x40
77	#define BPF_MEM 0x60
78	#define BPF_LEN 0x80
79	#define BPF_MSH 0xa0
80
81	/* alu/jmp fields */
82	#define BPF_OP(code) ((code) & 0xf0)
83	#define BPF_ADD 0x00
84	#define BPF_SUB 0x10
85	#define BPF_MUL 0x20
86	#define BPF_DIV 0x30
87	#define BPF_OR 0x40
88	#define BPF_AND 0x50
89	#define BPF_LSH 0x60
90	#define BPF_RSH 0x70
91	#define BPF_NEG 0x80
92	#define BPF_JA 0x00
93	#define BPF_JEQ 0x10
94	#define BPF_JGT 0x20
95	#define BPF_JGE 0x30
96	#define BPF_JSET 0x40
97	#define BPF_SRC(code) ((code) & 0x08)
98	#define BPF_K 0x00
99	#define BPF_X 0x08
100
101	/* ret - BPF_K and BPF_X also apply */
102	#define BPF_RVAL(code) ((code) & 0x18)
103	#define BPF_A 0x10
104
105	/* misc */
106	#define BPF_MISCOP(code) ((code) & 0xf8)
107	#define BPF_TAX 0x00
108	#define BPF_TXA 0x80
109
110	#ifndef BPF_MAXINSNS
111	#define BPF_MAXINSNS 4096
112	#endif
113
114	/*
115	* Macros for filter block array initializers.
116	*/
117	#ifndef BPF_STMT
118	#define BPF_STMT(code, k) { (unsigned short)(code), 0, 0, k }
119	#endif
120	#ifndef BPF_JUMP
121	#define BPF_JUMP(code, k, jt, jf) { (unsigned short)(code), jt, jf, k }
122	#endif
123
124	/*
125	* Number of scratch memory words for: BPF_ST and BPF_STX
126	*/
127	#define BPF_MEMWORDS 16
128
129	/* RATIONALE. Negative offsets are invalid in BPF.
130	We use them to reference ancillary data.
131	Unlike introduction new instructions, it does not break
132	existing compilers/optimizers.
133	*/
134	#define SKF_AD_OFF (-0x1000)
135	#define SKF_AD_PROTOCOL 0
136	#define SKF_AD_PKTTYPE 4
137	#define SKF_AD_IFINDEX 8
138	#define SKF_AD_MAX 12
139	#define SKF_NET_OFF (-0x100000)
140	#define SKF_LL_OFF (-0x200000)
141
142	#ifdef __KERNEL__
143	struct sk_buff;
144	struct sock;
145
146	extern int sk_run_filter(struct sk_buff skb, struct sock_filter filter, int flen);
147	extern int sk_attach_filter(struct sock_fprog fprog, struct sock sk);
148	extern int sk_chk_filter(struct sock_filter *filter, int flen);
149	#endif /* __KERNEL__ */
150
151	#endif /* __LINUX_FILTER_H__ */