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 }; 122 123 /* flags for BPF_MAP_UPDATE_ELEM command */ 124 #define BPF_ANY 0 /* create new element or update existing */ 125 #define BPF_NOEXIST 1 /* create new element if it didn't exist */ 126 #define BPF_EXIST 2 /* update existing element */ 127 128 union bpf_attr { 129 struct { /* anonymous struct used by BPF_MAP_CREATE command */ 130 __u32 map_type; /* one of enum bpf_map_type */ 131 __u32 key_size; /* size of key in bytes */ 132 __u32 value_size; /* size of value in bytes */ 133 __u32 max_entries; /* max number of entries in a map */ 134 }; 135 136 struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */ 137 __u32 map_fd; 138 __aligned_u64 key; 139 union { 140 __aligned_u64 value; 141 __aligned_u64 next_key; 142 }; 143 __u64 flags; 144 }; 145 146 struct { /* anonymous struct used by BPF_PROG_LOAD command */ 147 __u32 prog_type; /* one of enum bpf_prog_type */ 148 __u32 insn_cnt; 149 __aligned_u64 insns; 150 __aligned_u64 license; 151 __u32 log_level; /* verbosity level of verifier */ 152 __u32 log_size; /* size of user buffer */ 153 __aligned_u64 log_buf; /* user supplied buffer */ 154 }; 155 } __attribute__((aligned(8))); 156 157 /* integer value in 'imm' field of BPF_CALL instruction selects which helper 158 * function eBPF program intends to call 159 */ 160 enum bpf_func_id { 161 BPF_FUNC_unspec, 162 BPF_FUNC_map_lookup_elem, /* void *map_lookup_elem(&map, &key) */ 163 BPF_FUNC_map_update_elem, /* int map_update_elem(&map, &key, &value, flags) */ 164 BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */ 165 __BPF_FUNC_MAX_ID, 166 }; 167 168 #endif /* _UAPI__LINUX_BPF_H__ */ 169