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 _LINUX_BPF_H 8#define _LINUX_BPF_H 1 9 10#include <uapi/linux/bpf.h> 11#include <linux/workqueue.h> 12#include <linux/file.h> 13 14struct bpf_map; 15 16/* map is generic key/value storage optionally accesible by eBPF programs */ 17struct bpf_map_ops { 18 /* funcs callable from userspace (via syscall) */ 19 struct bpf_map *(*map_alloc)(union bpf_attr *attr); 20 void (*map_free)(struct bpf_map *); 21 int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key); 22 23 /* funcs callable from userspace and from eBPF programs */ 24 void *(*map_lookup_elem)(struct bpf_map *map, void *key); 25 int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags); 26 int (*map_delete_elem)(struct bpf_map *map, void *key); 27}; 28 29struct bpf_map { 30 atomic_t refcnt; 31 enum bpf_map_type map_type; 32 u32 key_size; 33 u32 value_size; 34 u32 max_entries; 35 const struct bpf_map_ops *ops; 36 struct work_struct work; 37}; 38 39struct bpf_map_type_list { 40 struct list_head list_node; 41 const struct bpf_map_ops *ops; 42 enum bpf_map_type type; 43}; 44 45/* function argument constraints */ 46enum bpf_arg_type { 47 ARG_DONTCARE = 0, /* unused argument in helper function */ 48 49 /* the following constraints used to prototype 50 * bpf_map_lookup/update/delete_elem() functions 51 */ 52 ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */ 53 ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */ 54 ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */ 55 56 /* the following constraints used to prototype bpf_memcmp() and other 57 * functions that access data on eBPF program stack 58 */ 59 ARG_PTR_TO_STACK, /* any pointer to eBPF program stack */ 60 ARG_CONST_STACK_SIZE, /* number of bytes accessed from stack */ 61 62 ARG_PTR_TO_CTX, /* pointer to context */ 63 ARG_ANYTHING, /* any (initialized) argument is ok */ 64}; 65 66/* type of values returned from helper functions */ 67enum bpf_return_type { 68 RET_INTEGER, /* function returns integer */ 69 RET_VOID, /* function doesn't return anything */ 70 RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */ 71}; 72 73/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs 74 * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL 75 * instructions after verifying 76 */ 77struct bpf_func_proto { 78 u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 79 bool gpl_only; 80 enum bpf_return_type ret_type; 81 enum bpf_arg_type arg1_type; 82 enum bpf_arg_type arg2_type; 83 enum bpf_arg_type arg3_type; 84 enum bpf_arg_type arg4_type; 85 enum bpf_arg_type arg5_type; 86}; 87 88/* bpf_context is intentionally undefined structure. Pointer to bpf_context is 89 * the first argument to eBPF programs. 90 * For socket filters: 'struct bpf_context *' == 'struct sk_buff *' 91 */ 92struct bpf_context; 93 94enum bpf_access_type { 95 BPF_READ = 1, 96 BPF_WRITE = 2 97}; 98 99struct bpf_verifier_ops { 100 /* return eBPF function prototype for verification */ 101 const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id); 102 103 /* return true if 'size' wide access at offset 'off' within bpf_context 104 * with 'type' (read or write) is allowed 105 */ 106 bool (*is_valid_access)(int off, int size, enum bpf_access_type type); 107 108 u32 (*convert_ctx_access)(int dst_reg, int src_reg, int ctx_off, 109 struct bpf_insn *insn); 110}; 111 112struct bpf_prog_type_list { 113 struct list_head list_node; 114 const struct bpf_verifier_ops *ops; 115 enum bpf_prog_type type; 116}; 117 118struct bpf_prog; 119 120struct bpf_prog_aux { 121 atomic_t refcnt; 122 u32 used_map_cnt; 123 const struct bpf_verifier_ops *ops; 124 struct bpf_map **used_maps; 125 struct bpf_prog *prog; 126 struct work_struct work; 127}; 128 129#ifdef CONFIG_BPF_SYSCALL 130void bpf_register_prog_type(struct bpf_prog_type_list *tl); 131void bpf_register_map_type(struct bpf_map_type_list *tl); 132 133struct bpf_prog *bpf_prog_get(u32 ufd); 134void bpf_prog_put(struct bpf_prog *prog); 135 136struct bpf_map *bpf_map_get(struct fd f); 137void bpf_map_put(struct bpf_map *map); 138 139/* verify correctness of eBPF program */ 140int bpf_check(struct bpf_prog **fp, union bpf_attr *attr); 141#else 142static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl) 143{ 144} 145 146static inline struct bpf_prog *bpf_prog_get(u32 ufd) 147{ 148 return ERR_PTR(-EOPNOTSUPP); 149} 150 151static inline void bpf_prog_put(struct bpf_prog *prog) 152{ 153} 154#endif /* CONFIG_BPF_SYSCALL */ 155 156/* verifier prototypes for helper functions called from eBPF programs */ 157extern const struct bpf_func_proto bpf_map_lookup_elem_proto; 158extern const struct bpf_func_proto bpf_map_update_elem_proto; 159extern const struct bpf_func_proto bpf_map_delete_elem_proto; 160 161extern const struct bpf_func_proto bpf_get_prandom_u32_proto; 162extern const struct bpf_func_proto bpf_get_smp_processor_id_proto; 163 164#endif /* _LINUX_BPF_H */ 165