include/uapi/linux/bpf.h

   1 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
   2  *
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of version 2 of the GNU General Public
   5  * License as published by the Free Software Foundation.
   6  */
   7 #ifndef _UAPI__LINUX_BPF_H__
   8 #define _UAPI__LINUX_BPF_H__
   9
  10 #include <linux/types.h>
  11 #include <linux/bpf_common.h>
  12
  13 /* Extended instruction set based on top of classic BPF */
  14
  15 /* instruction classes */
  16 #define BPF_ALU64       0x07    /* alu mode in double word width */
  17
  18 /* ld/ldx fields */
  19 #define BPF_DW          0x18    /* double word */
  20 #define BPF_XADD        0xc0    /* exclusive add */
  21
  22 /* alu/jmp fields */
  23 #define BPF_MOV         0xb0    /* mov reg to reg */
  24 #define BPF_ARSH        0xc0    /* sign extending arithmetic shift right */
  25
  26 /* change endianness of a register */
  27 #define BPF_END         0xd0    /* flags for endianness conversion: */
  28 #define BPF_TO_LE       0x00    /* convert to little-endian */
  29 #define BPF_TO_BE       0x08    /* convert to big-endian */
  30 #define BPF_FROM_LE     BPF_TO_LE
  31 #define BPF_FROM_BE     BPF_TO_BE
  32
  33 #define BPF_JNE         0x50    /* jump != */
  34 #define BPF_JSGT        0x60    /* SGT is signed '>', GT in x86 */
  35 #define BPF_JSGE        0x70    /* SGE is signed '>=', GE in x86 */
  36 #define BPF_CALL        0x80    /* function call */
  37 #define BPF_EXIT        0x90    /* function return */
  38
  39 /* Register numbers */
  40 enum {
  41         BPF_REG_0 = 0,
  42         BPF_REG_1,
  43         BPF_REG_2,
  44         BPF_REG_3,
  45         BPF_REG_4,
  46         BPF_REG_5,
  47         BPF_REG_6,
  48         BPF_REG_7,
  49         BPF_REG_8,
  50         BPF_REG_9,
  51         BPF_REG_10,
  52         __MAX_BPF_REG,
  53 };
  54
  55 /* BPF has 10 general purpose 64-bit registers and stack frame. */
  56 #define MAX_BPF_REG     __MAX_BPF_REG
  57
  58 struct bpf_insn {
  59         __u8    code;           /* opcode */
  60         __u8    dst_reg:4;      /* dest register */
  61         __u8    src_reg:4;      /* source register */
  62         __s16   off;            /* signed offset */
  63         __s32   imm;            /* signed immediate constant */
  64 };
  65
  66 /* BPF syscall commands */
  67 enum bpf_cmd {
  68         /* create a map with given type and attributes
  69          * fd = bpf(BPF_MAP_CREATE, union bpf_attr *, u32 size)
  70          * returns fd or negative error
  71          * map is deleted when fd is closed
  72          */
  73         BPF_MAP_CREATE,
  74
  75         /* lookup key in a given map
  76          * err = bpf(BPF_MAP_LOOKUP_ELEM, union bpf_attr *attr, u32 size)
  77          * Using attr->map_fd, attr->key, attr->value
  78          * returns zero and stores found elem into value
  79          * or negative error
  80          */
  81         BPF_MAP_LOOKUP_ELEM,
  82
  83         /* create or update key/value pair in a given map
  84          * err = bpf(BPF_MAP_UPDATE_ELEM, union bpf_attr *attr, u32 size)
  85          * Using attr->map_fd, attr->key, attr->value, attr->flags
  86          * returns zero or negative error
  87          */
  88         BPF_MAP_UPDATE_ELEM,
  89
  90         /* find and delete elem by key in a given map
  91          * err = bpf(BPF_MAP_DELETE_ELEM, union bpf_attr *attr, u32 size)
  92          * Using attr->map_fd, attr->key
  93          * returns zero or negative error
  94          */
  95         BPF_MAP_DELETE_ELEM,
  96
  97         /* lookup key in a given map and return next key
  98          * err = bpf(BPF_MAP_GET_NEXT_KEY, union bpf_attr *attr, u32 size)
  99          * Using attr->map_fd, attr->key, attr->next_key
 100          * returns zero and stores next key or negative error
 101          */
 102         BPF_MAP_GET_NEXT_KEY,
 103
 104         /* verify and load eBPF program
 105          * prog_fd = bpf(BPF_PROG_LOAD, union bpf_attr *attr, u32 size)
 106          * Using attr->prog_type, attr->insns, attr->license
 107          * returns fd or negative error
 108          */
 109         BPF_PROG_LOAD,
 110 };
 111
 112 enum bpf_map_type {
 113         BPF_MAP_TYPE_UNSPEC,
 114         BPF_MAP_TYPE_HASH,
 115         BPF_MAP_TYPE_ARRAY,
 116 };
 117
 118 enum bpf_prog_type {
 119         BPF_PROG_TYPE_UNSPEC,
 120         BPF_PROG_TYPE_SOCKET_FILTER,
 121         BPF_PROG_TYPE_KPROBE,
 122         BPF_PROG_TYPE_SCHED_CLS,
 123         BPF_PROG_TYPE_SCHED_ACT,
 124 };
 125
 126 #define BPF_PSEUDO_MAP_FD       1
 127
 128 /* flags for BPF_MAP_UPDATE_ELEM command */
 129 #define BPF_ANY         0 /* create new element or update existing */
 130 #define BPF_NOEXIST     1 /* create new element if it didn't exist */
 131 #define BPF_EXIST       2 /* update existing element */
 132
 133 union bpf_attr {
 134         struct { /* anonymous struct used by BPF_MAP_CREATE command */
 135                 __u32   map_type;       /* one of enum bpf_map_type */
 136                 __u32   key_size;       /* size of key in bytes */
 137                 __u32   value_size;     /* size of value in bytes */
 138                 __u32   max_entries;    /* max number of entries in a map */
 139         };
 140
 141         struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
 142                 __u32           map_fd;
 143                 __aligned_u64   key;
 144                 union {
 145                         __aligned_u64 value;
 146                         __aligned_u64 next_key;
 147                 };
 148                 __u64           flags;
 149         };
 150
 151         struct { /* anonymous struct used by BPF_PROG_LOAD command */
 152                 __u32           prog_type;      /* one of enum bpf_prog_type */
 153                 __u32           insn_cnt;
 154                 __aligned_u64   insns;
 155                 __aligned_u64   license;
 156                 __u32           log_level;      /* verbosity level of verifier */
 157                 __u32           log_size;       /* size of user buffer */
 158                 __aligned_u64   log_buf;        /* user supplied buffer */
 159                 __u32           kern_version;   /* checked when prog_type=kprobe */
 160         };
 161 } __attribute__((aligned(8)));
 162
 163 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
 164  * function eBPF program intends to call
 165  */
 166 enum bpf_func_id {
 167         BPF_FUNC_unspec,
 168         BPF_FUNC_map_lookup_elem, /* void *map_lookup_elem(&map, &key) */
 169         BPF_FUNC_map_update_elem, /* int map_update_elem(&map, &key, &value, flags) */
 170         BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */
 171         BPF_FUNC_probe_read,      /* int bpf_probe_read(void *dst, int size, void *src) */
 172         BPF_FUNC_ktime_get_ns,    /* u64 bpf_ktime_get_ns(void) */
 173         BPF_FUNC_trace_printk,    /* int bpf_trace_printk(const char *fmt, int fmt_size, ...) */
 174         BPF_FUNC_get_prandom_u32, /* u32 prandom_u32(void) */
 175         BPF_FUNC_get_smp_processor_id, /* u32 raw_smp_processor_id(void) */
 176
 177         /**
 178          * skb_store_bytes(skb, offset, from, len, flags) - store bytes into packet
 179          * @skb: pointer to skb
 180          * @offset: offset within packet from skb->data
 181          * @from: pointer where to copy bytes from
 182          * @len: number of bytes to store into packet
 183          * @flags: bit 0 - if true, recompute skb->csum
 184          *         other bits - reserved
 185          * Return: 0 on success
 186          */
 187         BPF_FUNC_skb_store_bytes,
 188
 189         /**
 190          * l3_csum_replace(skb, offset, from, to, flags) - recompute IP checksum
 191          * @skb: pointer to skb
 192          * @offset: offset within packet where IP checksum is located
 193          * @from: old value of header field
 194          * @to: new value of header field
 195          * @flags: bits 0-3 - size of header field
 196          *         other bits - reserved
 197          * Return: 0 on success
 198          */
 199         BPF_FUNC_l3_csum_replace,
 200
 201         /**
 202          * l4_csum_replace(skb, offset, from, to, flags) - recompute TCP/UDP checksum
 203          * @skb: pointer to skb
 204          * @offset: offset within packet where TCP/UDP checksum is located
 205          * @from: old value of header field
 206          * @to: new value of header field
 207          * @flags: bits 0-3 - size of header field
 208          *         bit 4 - is pseudo header
 209          *         other bits - reserved
 210          * Return: 0 on success
 211          */
 212         BPF_FUNC_l4_csum_replace,
 213         __BPF_FUNC_MAX_ID,
 214 };
 215
 216 /* user accessible mirror of in-kernel sk_buff.
 217  * new fields can only be added to the end of this structure
 218  */
 219 struct __sk_buff {
 220         __u32 len;
 221         __u32 pkt_type;
 222         __u32 mark;
 223         __u32 queue_mapping;
 224         __u32 protocol;
 225         __u32 vlan_present;
 226         __u32 vlan_tci;
 227         __u32 vlan_proto;
 228         __u32 priority;
 229 };
 230
 231 #endif /* _UAPI__LINUX_BPF_H__ */