filter.h
上传用户:szlgq88
上传日期:2009-04-28
资源大小:48287k
文件大小:4k
- /*
- * 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__ */