[deliverable/linux.git] / include / linux / bpf.h

/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 */
#ifndef _LINUX_BPF_H
#define _LINUX_BPF_H 1

#include <uapi/linux/bpf.h>
#include <linux/workqueue.h>
#include <linux/file.h>

struct bpf_map;

/* map is generic key/value storage optionally accesible by eBPF programs */
struct bpf_map_ops {
	/* funcs callable from userspace (via syscall) */
	struct bpf_map *(*map_alloc)(union bpf_attr *attr);
	void (*map_free)(struct bpf_map *);
	int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key);

	/* funcs callable from userspace and from eBPF programs */
	void *(*map_lookup_elem)(struct bpf_map *map, void *key);
	int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags);
	int (*map_delete_elem)(struct bpf_map *map, void *key);
};

struct bpf_map {
	atomic_t refcnt;
	enum bpf_map_type map_type;
	u32 key_size;
	u32 value_size;
	u32 max_entries;
	const struct bpf_map_ops *ops;
	struct work_struct work;
};

struct bpf_map_type_list {
	struct list_head list_node;
	const struct bpf_map_ops *ops;
	enum bpf_map_type type;
};

/* function argument constraints */
enum bpf_arg_type {
	ARG_DONTCARE = 0,	/* unused argument in helper function */

	/* the following constraints used to prototype
	 * bpf_map_lookup/update/delete_elem() functions
	 */
	ARG_CONST_MAP_PTR,	/* const argument used as pointer to bpf_map */
	ARG_PTR_TO_MAP_KEY,	/* pointer to stack used as map key */
	ARG_PTR_TO_MAP_VALUE,	/* pointer to stack used as map value */

	/* the following constraints used to prototype bpf_memcmp() and other
	 * functions that access data on eBPF program stack
	 */
	ARG_PTR_TO_STACK,	/* any pointer to eBPF program stack */
	ARG_CONST_STACK_SIZE,	/* number of bytes accessed from stack */

	ARG_ANYTHING,		/* any (initialized) argument is ok */
};

/* type of values returned from helper functions */
enum bpf_return_type {
	RET_INTEGER,			/* function returns integer */
	RET_VOID,			/* function doesn't return anything */
	RET_PTR_TO_MAP_VALUE_OR_NULL,	/* returns a pointer to map elem value or NULL */
};

/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
 * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
 * instructions after verifying
 */
struct bpf_func_proto {
	u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
	bool gpl_only;
	enum bpf_return_type ret_type;
	enum bpf_arg_type arg1_type;
	enum bpf_arg_type arg2_type;
	enum bpf_arg_type arg3_type;
	enum bpf_arg_type arg4_type;
	enum bpf_arg_type arg5_type;
};

/* bpf_context is intentionally undefined structure. Pointer to bpf_context is
 * the first argument to eBPF programs.
 * For socket filters: 'struct bpf_context *' == 'struct sk_buff *'
 */
struct bpf_context;

enum bpf_access_type {
	BPF_READ = 1,
	BPF_WRITE = 2
};

struct bpf_verifier_ops {
	/* return eBPF function prototype for verification */
	const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id);

	/* return true if 'size' wide access at offset 'off' within bpf_context
	 * with 'type' (read or write) is allowed
	 */
	bool (*is_valid_access)(int off, int size, enum bpf_access_type type);
};

struct bpf_prog_type_list {
	struct list_head list_node;
	const struct bpf_verifier_ops *ops;
	enum bpf_prog_type type;
};

struct bpf_prog;

struct bpf_prog_aux {
	atomic_t refcnt;
	u32 used_map_cnt;
	const struct bpf_verifier_ops *ops;
	struct bpf_map **used_maps;
	struct bpf_prog *prog;
	struct work_struct work;
};

#ifdef CONFIG_BPF_SYSCALL
void bpf_register_prog_type(struct bpf_prog_type_list *tl);
void bpf_register_map_type(struct bpf_map_type_list *tl);

struct bpf_prog *bpf_prog_get(u32 ufd);
void bpf_prog_put(struct bpf_prog *prog);

struct bpf_map *bpf_map_get(struct fd f);
void bpf_map_put(struct bpf_map *map);

/* verify correctness of eBPF program */
int bpf_check(struct bpf_prog *fp, union bpf_attr *attr);
#else
static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl)
{
}

static inline struct bpf_prog *bpf_prog_get(u32 ufd)
{
	return ERR_PTR(-EOPNOTSUPP);
}

static inline void bpf_prog_put(struct bpf_prog *prog)
{
}
#endif /* CONFIG_BPF_SYSCALL */

/* verifier prototypes for helper functions called from eBPF programs */
extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
extern const struct bpf_func_proto bpf_map_update_elem_proto;
extern const struct bpf_func_proto bpf_map_delete_elem_proto;

extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;

#endif /* _LINUX_BPF_H */
Commit	Line	Data
99c55f7d AS	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>
db20fd2b	12	#include <linux/file.h>
99c55f7d AS	13
	14	struct bpf_map;
	15
	16	/* map is generic key/value storage optionally accesible by eBPF programs */
	17	struct 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 );
db20fd2b AS	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);
3274f520	25	int (map_update_elem)(struct bpf_map map, void key, void value, u64 flags);
db20fd2b	26	int (map_delete_elem)(struct bpf_map map, void *key);
99c55f7d AS	27	};
	28
	29	struct 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;
a2c83fff	35	const struct bpf_map_ops *ops;
99c55f7d AS	36	struct work_struct work;
	37	};
	38
	39	struct bpf_map_type_list {
	40	struct list_head list_node;
a2c83fff	41	const struct bpf_map_ops *ops;
99c55f7d AS	42	enum bpf_map_type type;
	43	};
	44
17a52670 AS	45	/* function argument constraints */
17a52670 AS	46	enum bpf_arg_type {
80f1d68c	47	ARG_DONTCARE = 0, /* unused argument in helper function */
17a52670 AS	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 */
80f1d68c DB	61
80f1d68c DB	62	ARG_ANYTHING, /* any (initialized) argument is ok */
17a52670 AS	63	};
	64
	65	/* type of values returned from helper functions */
	66	enum bpf_return_type {
	67	RET_INTEGER, /* function returns integer */
	68	RET_VOID, /* function doesn't return anything */
	69	RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */
	70	};
	71
09756af4 AS	72	/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
	73	* to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
	74	* instructions after verifying
	75	*/
	76	struct bpf_func_proto {
	77	u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
	78	bool gpl_only;
17a52670 AS	79	enum bpf_return_type ret_type;
	80	enum bpf_arg_type arg1_type;
	81	enum bpf_arg_type arg2_type;
	82	enum bpf_arg_type arg3_type;
	83	enum bpf_arg_type arg4_type;
	84	enum bpf_arg_type arg5_type;
	85	};
	86
	87	/* bpf_context is intentionally undefined structure. Pointer to bpf_context is
	88	* the first argument to eBPF programs.
	89	* For socket filters: 'struct bpf_context ' == 'struct sk_buff '
	90	*/
	91	struct bpf_context;
	92
	93	enum bpf_access_type {
	94	BPF_READ = 1,
	95	BPF_WRITE = 2
09756af4 AS	96	};
	97
	98	struct bpf_verifier_ops {
	99	/* return eBPF function prototype for verification */
	100	const struct bpf_func_proto (get_func_proto)(enum bpf_func_id func_id);
17a52670 AS	101
	102	/* return true if 'size' wide access at offset 'off' within bpf_context
	103	* with 'type' (read or write) is allowed
	104	*/
	105	bool (*is_valid_access)(int off, int size, enum bpf_access_type type);
09756af4 AS	106	};
	107
	108	struct bpf_prog_type_list {
	109	struct list_head list_node;
a2c83fff	110	const struct bpf_verifier_ops *ops;
09756af4 AS	111	enum bpf_prog_type type;
	112	};
	113
09756af4 AS	114	struct bpf_prog;
	115
	116	struct bpf_prog_aux {
	117	atomic_t refcnt;
24701ece	118	u32 used_map_cnt;
a2c83fff	119	const struct bpf_verifier_ops *ops;
09756af4	120	struct bpf_map **used_maps;
09756af4 AS	121	struct bpf_prog *prog;
	122	struct work_struct work;
	123	};
	124
89aa0758	125	#ifdef CONFIG_BPF_SYSCALL
0fc174de	126	void bpf_register_prog_type(struct bpf_prog_type_list *tl);
61e021f3	127	void bpf_register_map_type(struct bpf_map_type_list *tl);
0fc174de	128
0fc174de	129	struct bpf_prog *bpf_prog_get(u32 ufd);
61e021f3 DB	130	void bpf_prog_put(struct bpf_prog *prog);
	131
	132	struct bpf_map *bpf_map_get(struct fd f);
	133	void bpf_map_put(struct bpf_map *map);
	134
	135	/* verify correctness of eBPF program */
	136	int bpf_check(struct bpf_prog fp, union bpf_attr attr);
89aa0758	137	#else
0fc174de DB	138	static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl)
	139	{
	140	}
	141
	142	static inline struct bpf_prog *bpf_prog_get(u32 ufd)
	143	{
	144	return ERR_PTR(-EOPNOTSUPP);
	145	}
	146
	147	static inline void bpf_prog_put(struct bpf_prog *prog)
	148	{
	149	}
61e021f3	150	#endif /* CONFIG_BPF_SYSCALL */
09756af4	151
d0003ec0	152	/* verifier prototypes for helper functions called from eBPF programs */
a2c83fff DB	153	extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
	154	extern const struct bpf_func_proto bpf_map_update_elem_proto;
	155	extern const struct bpf_func_proto bpf_map_delete_elem_proto;
d0003ec0	156
03e69b50	157	extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
c04167ce	158	extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
03e69b50	159
99c55f7d	160	#endif /* _LINUX_BPF_H */