1/* 2 * Linux Socket Filter Data Structures 3 */ 4 5#ifndef __LINUX_FILTER_H__ 6#define __LINUX_FILTER_H__ 7 8#include <linux/compiler.h> 9#include <linux/types.h> 10 11#ifdef __KERNEL__ 12#include <asm/atomic.h> 13#endif 14 15/* 16 * Current version of the filter code architecture. 17 */ 18#define BPF_MAJOR_VERSION 1 19#define BPF_MINOR_VERSION 1 20 21/* 22 * Try and keep these values and structures similar to BSD, especially 23 * the BPF code definitions which need to match so you can share filters 24 */ 25 26struct sock_filter /* Filter block */ 27{ 28 __u16 code; /* Actual filter code */ 29 __u8 jt; /* Jump true */ 30 __u8 jf; /* Jump false */ 31 __u32 k; /* Generic multiuse field */ 32}; 33 34struct sock_fprog /* Required for SO_ATTACH_FILTER. */ 35{ 36 unsigned short len; /* Number of filter blocks */ 37 struct sock_filter __user *filter; 38}; 39 40#ifdef __KERNEL__ 41struct sk_filter 42{ 43 atomic_t refcnt; 44 unsigned int len; /* Number of filter blocks */ 45 struct sock_filter insns[0]; 46}; 47 48static inline unsigned int sk_filter_len(struct sk_filter *fp) 49{ 50 return fp->len*sizeof(struct sock_filter) + sizeof(*fp); 51} 52#endif 53 54/* 55 * Instruction classes 56 */ 57 58#define BPF_CLASS(code) ((code) & 0x07) 59#define BPF_LD 0x00 60#define BPF_LDX 0x01 61#define BPF_ST 0x02 62#define BPF_STX 0x03 63#define BPF_ALU 0x04 64#define BPF_JMP 0x05 65#define BPF_RET 0x06 66#define BPF_MISC 0x07 67 68/* ld/ldx fields */ 69#define BPF_SIZE(code) ((code) & 0x18) 70#define BPF_W 0x00 71#define BPF_H 0x08 72#define BPF_B 0x10 73#define BPF_MODE(code) ((code) & 0xe0) 74#define BPF_IMM 0x00 75#define BPF_ABS 0x20 76#define BPF_IND 0x40 77#define BPF_MEM 0x60 78#define BPF_LEN 0x80 79#define BPF_MSH 0xa0 80 81/* alu/jmp fields */ 82#define BPF_OP(code) ((code) & 0xf0) 83#define BPF_ADD 0x00 84#define BPF_SUB 0x10 85#define BPF_MUL 0x20 86#define BPF_DIV 0x30 87#define BPF_OR 0x40 88#define BPF_AND 0x50 89#define BPF_LSH 0x60 90#define BPF_RSH 0x70 91#define BPF_NEG 0x80 92#define BPF_JA 0x00 93#define BPF_JEQ 0x10 94#define BPF_JGT 0x20 95#define BPF_JGE 0x30 96#define BPF_JSET 0x40 97#define BPF_SRC(code) ((code) & 0x08) 98#define BPF_K 0x00 99#define BPF_X 0x08 100 101/* ret - BPF_K and BPF_X also apply */ 102#define BPF_RVAL(code) ((code) & 0x18) 103#define BPF_A 0x10 104 105/* misc */ 106#define BPF_MISCOP(code) ((code) & 0xf8) 107#define BPF_TAX 0x00 108#define BPF_TXA 0x80 109 110#ifndef BPF_MAXINSNS 111#define BPF_MAXINSNS 4096 112#endif 113 114/* 115 * Macros for filter block array initializers. 116 */ 117#ifndef BPF_STMT 118#define BPF_STMT(code, k) { (unsigned short)(code), 0, 0, k } 119#endif 120#ifndef BPF_JUMP 121#define BPF_JUMP(code, k, jt, jf) { (unsigned short)(code), jt, jf, k } 122#endif 123 124/* 125 * Number of scratch memory words for: BPF_ST and BPF_STX 126 */ 127#define BPF_MEMWORDS 16 128 129/* RATIONALE. Negative offsets are invalid in BPF. 130 We use them to reference ancillary data. 131 Unlike introduction new instructions, it does not break 132 existing compilers/optimizers. 133 */ 134#define SKF_AD_OFF (-0x1000) 135#define SKF_AD_PROTOCOL 0 136#define SKF_AD_PKTTYPE 4 137#define SKF_AD_IFINDEX 8 138#define SKF_AD_MAX 12 139#define SKF_NET_OFF (-0x100000) 140#define SKF_LL_OFF (-0x200000) 141 142#ifdef __KERNEL__ 143struct sk_buff; 144struct sock; 145 146extern unsigned int sk_run_filter(struct sk_buff *skb, struct sock_filter *filter, int flen); 147extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 148extern int sk_chk_filter(struct sock_filter *filter, int flen); 149#endif /* __KERNEL__ */ 150 151#endif /* __LINUX_FILTER_H__ */ 152