1/* 2 * Linux Socket Filter Data Structures 3 */ 4 5#ifndef __LINUX_FILTER_H__ 6#define __LINUX_FILTER_H__ 7 8/* 9 * Current version of the filter code architecture. 10 */ 11#define BPF_MAJOR_VERSION 1 12#define BPF_MINOR_VERSION 1 13 14/* 15 * Try and keep these values and structures similar to BSD, especially 16 * the BPF code definitions which need to match so you can share filters 17 */ 18 19struct sock_filter /* Filter block */ 20{ 21 __u16 code; /* Actual filter code */ 22 __u8 jt; /* Jump true */ 23 __u8 jf; /* Jump false */ 24 __u32 k; /* Generic multiuse field */ 25}; 26 27struct sock_fprog /* Required for SO_ATTACH_FILTER. */ 28{ 29 unsigned short len; /* Number of filter blocks */ 30 struct sock_filter *filter; 31}; 32 33#ifdef __KERNEL__ 34struct sk_filter 35{ 36 atomic_t refcnt; 37 unsigned int len; /* Number of filter blocks */ 38 struct sock_filter insns[0]; 39}; 40 41static inline unsigned int sk_filter_len(struct sk_filter *fp) 42{ 43 return fp->len*sizeof(struct sock_filter) + sizeof(*fp); 44} 45#endif 46 47/* 48 * Instruction classes 49 */ 50 51#define BPF_CLASS(code) ((code) & 0x07) 52#define BPF_LD 0x00 53#define BPF_LDX 0x01 54#define BPF_ST 0x02 55#define BPF_STX 0x03 56#define BPF_ALU 0x04 57#define BPF_JMP 0x05 58#define BPF_RET 0x06 59#define BPF_MISC 0x07 60 61/* ld/ldx fields */ 62#define BPF_SIZE(code) ((code) & 0x18) 63#define BPF_W 0x00 64#define BPF_H 0x08 65#define BPF_B 0x10 66#define BPF_MODE(code) ((code) & 0xe0) 67#define BPF_IMM 0x00 68#define BPF_ABS 0x20 69#define BPF_IND 0x40 70#define BPF_MEM 0x60 71#define BPF_LEN 0x80 72#define BPF_MSH 0xa0 73 74/* alu/jmp fields */ 75#define BPF_OP(code) ((code) & 0xf0) 76#define BPF_ADD 0x00 77#define BPF_SUB 0x10 78#define BPF_MUL 0x20 79#define BPF_DIV 0x30 80#define BPF_OR 0x40 81#define BPF_AND 0x50 82#define BPF_LSH 0x60 83#define BPF_RSH 0x70 84#define BPF_NEG 0x80 85#define BPF_JA 0x00 86#define BPF_JEQ 0x10 87#define BPF_JGT 0x20 88#define BPF_JGE 0x30 89#define BPF_JSET 0x40 90#define BPF_SRC(code) ((code) & 0x08) 91#define BPF_K 0x00 92#define BPF_X 0x08 93 94/* ret - BPF_K and BPF_X also apply */ 95#define BPF_RVAL(code) ((code) & 0x18) 96#define BPF_A 0x10 97 98/* misc */ 99#define BPF_MISCOP(code) ((code) & 0xf8) 100#define BPF_TAX 0x00 101#define BPF_TXA 0x80 102 103#ifndef BPF_MAXINSNS 104#define BPF_MAXINSNS 4096 105#endif 106 107/* 108 * Macros for filter block array initializers. 109 */ 110#ifndef BPF_STMT 111#define BPF_STMT(code, k) { (unsigned short)(code), 0, 0, k } 112#endif 113#ifndef BPF_JUMP 114#define BPF_JUMP(code, k, jt, jf) { (unsigned short)(code), jt, jf, k } 115#endif 116 117/* 118 * Number of scratch memory words for: BPF_ST and BPF_STX 119 */ 120#define BPF_MEMWORDS 16 121 122/* RATIONALE. Negative offsets are invalid in BPF. 123 We use them to reference ancillary data. 124 Unlike introduction new instructions, it does not break 125 existing compilers/optimizers. 126 */ 127#define SKF_AD_OFF (-0x1000) 128#define SKF_AD_PROTOCOL 0 129#define SKF_AD_PKTTYPE 4 130#define SKF_AD_IFINDEX 8 131#define SKF_AD_MAX 12 132#define SKF_NET_OFF (-0x100000) 133#define SKF_LL_OFF (-0x200000) 134 135#ifdef __KERNEL__ 136extern int sk_run_filter(struct sk_buff *skb, struct sock_filter *filter, int flen); 137extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 138extern int sk_chk_filter(struct sock_filter *filter, int flen); 139#endif /* __KERNEL__ */ 140 141#endif /* __LINUX_FILTER_H__ */ 142