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