include/uapi/linux/filter.h

   1 /*
   2  * Linux Socket Filter Data Structures
   3  */
   4
   5 #ifndef _UAPI__LINUX_FILTER_H__
   6 #define _UAPI__LINUX_FILTER_H__
   7
   8 #include <linux/compiler.h>
   9 #include <linux/types.h>
  10
  11
  12 /*
  13  * Current version of the filter code architecture.
  14  */
  15 #define BPF_MAJOR_VERSION 1
  16 #define BPF_MINOR_VERSION 1
  17
  18 /*
  19  *      Try and keep these values and structures similar to BSD, especially
  20  *      the BPF code definitions which need to match so you can share filters
  21  */
  22
  23 struct sock_filter {    /* Filter block */
  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         unsigned short          len;    /* Number of filter blocks */
  32         struct sock_filter __user *filter;
  33 };
  34
  35 /*
  36  * Instruction classes
  37  */
  38
  39 #define BPF_CLASS(code) ((code) & 0x07)
  40 #define         BPF_LD          0x00
  41 #define         BPF_LDX         0x01
  42 #define         BPF_ST          0x02
  43 #define         BPF_STX         0x03
  44 #define         BPF_ALU         0x04
  45 #define         BPF_JMP         0x05
  46 #define         BPF_RET         0x06
  47 #define         BPF_MISC        0x07
  48
  49 /* ld/ldx fields */
  50 #define BPF_SIZE(code)  ((code) & 0x18)
  51 #define         BPF_W           0x00
  52 #define         BPF_H           0x08
  53 #define         BPF_B           0x10
  54 #define BPF_MODE(code)  ((code) & 0xe0)
  55 #define         BPF_IMM         0x00
  56 #define         BPF_ABS         0x20
  57 #define         BPF_IND         0x40
  58 #define         BPF_MEM         0x60
  59 #define         BPF_LEN         0x80
  60 #define         BPF_MSH         0xa0
  61
  62 /* alu/jmp fields */
  63 #define BPF_OP(code)    ((code) & 0xf0)
  64 #define         BPF_ADD         0x00
  65 #define         BPF_SUB         0x10
  66 #define         BPF_MUL         0x20
  67 #define         BPF_DIV         0x30
  68 #define         BPF_OR          0x40
  69 #define         BPF_AND         0x50
  70 #define         BPF_LSH         0x60
  71 #define         BPF_RSH         0x70
  72 #define         BPF_NEG         0x80
  73 #define         BPF_MOD         0x90
  74 #define         BPF_XOR         0xa0
  75
  76 #define         BPF_JA          0x00
  77 #define         BPF_JEQ         0x10
  78 #define         BPF_JGT         0x20
  79 #define         BPF_JGE         0x30
  80 #define         BPF_JSET        0x40
  81 #define BPF_SRC(code)   ((code) & 0x08)
  82 #define         BPF_K           0x00
  83 #define         BPF_X           0x08
  84
  85 /* ret - BPF_K and BPF_X also apply */
  86 #define BPF_RVAL(code)  ((code) & 0x18)
  87 #define         BPF_A           0x10
  88
  89 /* misc */
  90 #define BPF_MISCOP(code) ((code) & 0xf8)
  91 #define         BPF_TAX         0x00
  92 #define         BPF_TXA         0x80
  93
  94 #ifndef BPF_MAXINSNS
  95 #define BPF_MAXINSNS 4096
  96 #endif
  97
  98 /*
  99  * Macros for filter block array initializers.
 100  */
 101 #ifndef BPF_STMT
 102 #define BPF_STMT(code, k) { (unsigned short)(code), 0, 0, k }
 103 #endif
 104 #ifndef BPF_JUMP
 105 #define BPF_JUMP(code, k, jt, jf) { (unsigned short)(code), jt, jf, k }
 106 #endif
 107
 108 /*
 109  * Number of scratch memory words for: BPF_ST and BPF_STX
 110  */
 111 #define BPF_MEMWORDS 16
 112
 113 /* RATIONALE. Negative offsets are invalid in BPF.
 114    We use them to reference ancillary data.
 115    Unlike introduction new instructions, it does not break
 116    existing compilers/optimizers.
 117  */
 118 #define SKF_AD_OFF    (-0x1000)
 119 #define SKF_AD_PROTOCOL 0
 120 #define SKF_AD_PKTTYPE  4
 121 #define SKF_AD_IFINDEX  8
 122 #define SKF_AD_NLATTR   12
 123 #define SKF_AD_NLATTR_NEST      16
 124 #define SKF_AD_MARK     20
 125 #define SKF_AD_QUEUE    24
 126 #define SKF_AD_HATYPE   28
 127 #define SKF_AD_RXHASH   32
 128 #define SKF_AD_CPU      36
 129 #define SKF_AD_ALU_XOR_X        40
 130 #define SKF_AD_VLAN_TAG 44
 131 #define SKF_AD_VLAN_TAG_PRESENT 48
 132 #define SKF_AD_PAY_OFFSET       52
 133 #define SKF_AD_MAX      56
 134 #define SKF_NET_OFF   (-0x100000)
 135 #define SKF_LL_OFF    (-0x200000)
 136
 137
 138 #endif /* _UAPI__LINUX_FILTER_H__ */