filter.h 4.1 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
/*
 * 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
 */
 
E
Eric Dumazet 已提交
26
struct sock_filter {	/* Filter block */
27 28 29 30
	__u16	code;   /* Actual filter code */
	__u8	jt;	/* Jump true */
	__u8	jf;	/* Jump false */
	__u32	k;      /* Generic multiuse field */
L
Linus Torvalds 已提交
31 32
};

E
Eric Dumazet 已提交
33
struct sock_fprog {	/* Required for SO_ATTACH_FILTER. */
L
Linus Torvalds 已提交
34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121
	unsigned short		len;	/* Number of filter blocks */
	struct sock_filter __user *filter;
};

/*
 * 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
122
#define SKF_AD_NLATTR	12
123
#define SKF_AD_NLATTR_NEST	16
J
jamal 已提交
124
#define SKF_AD_MARK 	20
125
#define SKF_AD_QUEUE	24
126
#define SKF_AD_HATYPE	28
127 128 129
#define SKF_AD_RXHASH	32
#define SKF_AD_CPU	36
#define SKF_AD_MAX	40
L
Linus Torvalds 已提交
130 131 132 133
#define SKF_NET_OFF   (-0x100000)
#define SKF_LL_OFF    (-0x200000)

#ifdef __KERNEL__
134 135 136 137 138 139 140 141 142 143 144 145 146
struct sk_filter
{
	atomic_t		refcnt;
	unsigned int         	len;	/* Number of filter blocks */
	struct rcu_head		rcu;
	struct sock_filter     	insns[0];
};

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

L
Linus Torvalds 已提交
147 148 149
struct sk_buff;
struct sock;

S
Stephen Hemminger 已提交
150
extern int sk_filter(struct sock *sk, struct sk_buff *skb);
151
extern unsigned int sk_run_filter(struct sk_buff *skb,
E
Eric Dumazet 已提交
152
				  const struct sock_filter *filter);
L
Linus Torvalds 已提交
153
extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
154
extern int sk_detach_filter(struct sock *sk);
L
Linus Torvalds 已提交
155 156 157 158
extern int sk_chk_filter(struct sock_filter *filter, int flen);
#endif /* __KERNEL__ */

#endif /* __LINUX_FILTER_H__ */