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Alexei Starovoitov99c55f72014-09-26 00:16:57 -07001/* 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>
Alexei Starovoitovdb20fd22014-09-26 00:16:59 -070012#include <linux/file.h>
Alexei Starovoitov99c55f72014-09-26 00:16:57 -070013
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 *);
Alexei Starovoitovdb20fd22014-09-26 00:16:59 -070021 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);
Alexei Starovoitov3274f522014-11-13 17:36:44 -080025 int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags);
Alexei Starovoitovdb20fd22014-09-26 00:16:59 -070026 int (*map_delete_elem)(struct bpf_map *map, void *key);
Alexei Starovoitov99c55f72014-09-26 00:16:57 -070027};
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;
Daniel Borkmanna2c83ff2015-03-01 12:31:42 +010035 const struct bpf_map_ops *ops;
Alexei Starovoitov99c55f72014-09-26 00:16:57 -070036 struct work_struct work;
37};
38
39struct bpf_map_type_list {
40 struct list_head list_node;
Daniel Borkmanna2c83ff2015-03-01 12:31:42 +010041 const struct bpf_map_ops *ops;
Alexei Starovoitov99c55f72014-09-26 00:16:57 -070042 enum bpf_map_type type;
43};
44
Alexei Starovoitov17a52672014-09-26 00:17:06 -070045/* function argument constraints */
46enum bpf_arg_type {
Daniel Borkmann80f1d682015-03-12 17:21:42 +010047 ARG_DONTCARE = 0, /* unused argument in helper function */
Alexei Starovoitov17a52672014-09-26 00:17:06 -070048
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 */
Daniel Borkmann80f1d682015-03-12 17:21:42 +010061
Alexei Starovoitov608cd712015-03-26 19:53:57 -070062 ARG_PTR_TO_CTX, /* pointer to context */
Daniel Borkmann80f1d682015-03-12 17:21:42 +010063 ARG_ANYTHING, /* any (initialized) argument is ok */
Alexei Starovoitov17a52672014-09-26 00:17:06 -070064};
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
Alexei Starovoitov09756af2014-09-26 00:17:00 -070073/* 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;
Alexei Starovoitov17a52672014-09-26 00:17:06 -070080 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
Alexei Starovoitov09756af2014-09-26 00:17:00 -070097};
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);
Alexei Starovoitov17a52672014-09-26 00:17:06 -0700102
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);
Alexei Starovoitov9bac3d62015-03-13 11:57:42 -0700107
108 u32 (*convert_ctx_access)(int dst_reg, int src_reg, int ctx_off,
109 struct bpf_insn *insn);
Alexei Starovoitov09756af2014-09-26 00:17:00 -0700110};
111
112struct bpf_prog_type_list {
113 struct list_head list_node;
Daniel Borkmanna2c83ff2015-03-01 12:31:42 +0100114 const struct bpf_verifier_ops *ops;
Alexei Starovoitov09756af2014-09-26 00:17:00 -0700115 enum bpf_prog_type type;
116};
117
Alexei Starovoitov09756af2014-09-26 00:17:00 -0700118struct bpf_prog;
119
120struct bpf_prog_aux {
121 atomic_t refcnt;
Daniel Borkmann24701ec2015-03-01 12:31:47 +0100122 u32 used_map_cnt;
Daniel Borkmanna2c83ff2015-03-01 12:31:42 +0100123 const struct bpf_verifier_ops *ops;
Alexei Starovoitov09756af2014-09-26 00:17:00 -0700124 struct bpf_map **used_maps;
Alexei Starovoitov09756af2014-09-26 00:17:00 -0700125 struct bpf_prog *prog;
126 struct work_struct work;
127};
128
Alexei Starovoitov89aa0752014-12-01 15:06:35 -0800129#ifdef CONFIG_BPF_SYSCALL
Daniel Borkmann0fc174d2015-03-01 12:31:44 +0100130void bpf_register_prog_type(struct bpf_prog_type_list *tl);
Daniel Borkmann61e021f2015-03-02 15:21:55 +0100131void bpf_register_map_type(struct bpf_map_type_list *tl);
Daniel Borkmann0fc174d2015-03-01 12:31:44 +0100132
Alexei Starovoitov09756af2014-09-26 00:17:00 -0700133struct bpf_prog *bpf_prog_get(u32 ufd);
Daniel Borkmann61e021f2015-03-02 15:21:55 +0100134void 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 */
Alexei Starovoitov9bac3d62015-03-13 11:57:42 -0700140int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
Daniel Borkmann0fc174d2015-03-01 12:31:44 +0100141#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}
Daniel Borkmann61e021f2015-03-02 15:21:55 +0100154#endif /* CONFIG_BPF_SYSCALL */
Alexei Starovoitov09756af2014-09-26 00:17:00 -0700155
Alexei Starovoitovd0003ec2014-11-13 17:36:49 -0800156/* verifier prototypes for helper functions called from eBPF programs */
Daniel Borkmanna2c83ff2015-03-01 12:31:42 +0100157extern 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;
Alexei Starovoitovd0003ec2014-11-13 17:36:49 -0800160
Daniel Borkmann03e69b52015-03-14 02:27:16 +0100161extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
Daniel Borkmannc04167c2015-03-14 02:27:17 +0100162extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
Daniel Borkmann03e69b52015-03-14 02:27:16 +0100163
Alexei Starovoitov99c55f72014-09-26 00:16:57 -0700164#endif /* _LINUX_BPF_H */