Linux Audio

Check our new training course

Loading...
/*
 * Linux Socket Filter Data Structures
 */

#ifndef __LINUX_FILTER_H__
#define __LINUX_FILTER_H__

/*
 * 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     *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

#define BPF_MAXINSNS 512

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

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

#ifdef __KERNEL__
extern int sk_run_filter(unsigned char *data, int len, struct sock_filter *filter, int flen);
extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
#endif /* __KERNEL__ */

#endif /* __LINUX_FILTER_H__ */
pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.


Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy