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