1 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
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.
10 #include <uapi/linux/bpf.h>
11 #include <linux/workqueue.h>
12 #include <linux/file.h>
16 /* map is generic key/value storage optionally accesible by eBPF programs */
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
);
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
);
31 enum bpf_map_type map_type
;
35 const struct bpf_map_ops
*ops
;
36 struct work_struct work
;
39 struct bpf_map_type_list
{
40 struct list_head list_node
;
41 const struct bpf_map_ops
*ops
;
42 enum bpf_map_type type
;
45 /* function argument constraints */
47 ARG_DONTCARE
= 0, /* unused argument in helper function */
49 /* the following constraints used to prototype
50 * bpf_map_lookup/update/delete_elem() functions
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 */
56 /* the following constraints used to prototype bpf_memcmp() and other
57 * functions that access data on eBPF program stack
59 ARG_PTR_TO_STACK
, /* any pointer to eBPF program stack */
60 ARG_CONST_STACK_SIZE
, /* number of bytes accessed from stack */
62 ARG_PTR_TO_CTX
, /* pointer to context */
63 ARG_ANYTHING
, /* any (initialized) argument is ok */
66 /* type of values returned from helper functions */
67 enum 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 */
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
77 struct bpf_func_proto
{
78 u64 (*func
)(u64 r1
, u64 r2
, u64 r3
, u64 r4
, u64 r5
);
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
;
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 *'
94 enum bpf_access_type
{
99 struct 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
);
103 /* return true if 'size' wide access at offset 'off' within bpf_context
104 * with 'type' (read or write) is allowed
106 bool (*is_valid_access
)(int off
, int size
, enum bpf_access_type type
);
108 u32 (*convert_ctx_access
)(int dst_reg
, int src_reg
, int ctx_off
,
109 struct bpf_insn
*insn
);
112 struct bpf_prog_type_list
{
113 struct list_head list_node
;
114 const struct bpf_verifier_ops
*ops
;
115 enum bpf_prog_type type
;
120 struct bpf_prog_aux
{
123 const struct bpf_verifier_ops
*ops
;
124 struct bpf_map
**used_maps
;
125 struct bpf_prog
*prog
;
126 struct work_struct work
;
132 /* 'ownership' of prog_array is claimed by the first program that
133 * is going to use this map or by the first program which FD is stored
134 * in the map to make sure that all callers and callees have the same
135 * prog_type and JITed flag
137 enum bpf_prog_type owner_prog_type
;
140 char value
[0] __aligned(8);
141 struct bpf_prog
*prog
[0] __aligned(8);
144 #define MAX_TAIL_CALL_CNT 32
146 u64
bpf_tail_call(u64 ctx
, u64 r2
, u64 index
, u64 r4
, u64 r5
);
147 void bpf_prog_array_map_clear(struct bpf_map
*map
);
148 bool bpf_prog_array_compatible(struct bpf_array
*array
, const struct bpf_prog
*fp
);
150 #ifdef CONFIG_BPF_SYSCALL
151 void bpf_register_prog_type(struct bpf_prog_type_list
*tl
);
152 void bpf_register_map_type(struct bpf_map_type_list
*tl
);
154 struct bpf_prog
*bpf_prog_get(u32 ufd
);
155 void bpf_prog_put(struct bpf_prog
*prog
);
157 struct bpf_map
*bpf_map_get(struct fd f
);
158 void bpf_map_put(struct bpf_map
*map
);
160 /* verify correctness of eBPF program */
161 int bpf_check(struct bpf_prog
**fp
, union bpf_attr
*attr
);
163 static inline void bpf_register_prog_type(struct bpf_prog_type_list
*tl
)
167 static inline struct bpf_prog
*bpf_prog_get(u32 ufd
)
169 return ERR_PTR(-EOPNOTSUPP
);
172 static inline void bpf_prog_put(struct bpf_prog
*prog
)
175 #endif /* CONFIG_BPF_SYSCALL */
177 /* verifier prototypes for helper functions called from eBPF programs */
178 extern const struct bpf_func_proto bpf_map_lookup_elem_proto
;
179 extern const struct bpf_func_proto bpf_map_update_elem_proto
;
180 extern const struct bpf_func_proto bpf_map_delete_elem_proto
;
182 extern const struct bpf_func_proto bpf_get_prandom_u32_proto
;
183 extern const struct bpf_func_proto bpf_get_smp_processor_id_proto
;
184 extern const struct bpf_func_proto bpf_tail_call_proto
;
186 #endif /* _LINUX_BPF_H */