/* * 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__ */