[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);

	/* funcs called by prog_array and perf_event_array map */
	void *(*map_fd_get_ptr) (struct bpf_map *map, int fd);
	void (*map_fd_put_ptr) (void *ptr);
};

struct bpf_map {
	atomic_t refcnt;
	enum bpf_map_type map_type;
	u32 key_size;
	u32 value_size;
	u32 max_entries;
	u32 pages;
	struct user_struct *user;
	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_PTR_TO_CTX,		/* pointer to context */
	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_prog;

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);

	u32 (*convert_ctx_access)(enum bpf_access_type type, int dst_reg,
				  int src_reg, int ctx_off,
				  struct bpf_insn *insn, struct bpf_prog *prog);
};

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

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 user_struct *user;
	union {
		struct work_struct work;
		struct rcu_head	rcu;
	};
};

struct bpf_array {
	struct bpf_map map;
	u32 elem_size;
	/* 'ownership' of prog_array is claimed by the first program that
	 * is going to use this map or by the first program which FD is stored
	 * in the map to make sure that all callers and callees have the same
	 * prog_type and JITed flag
	 */
	enum bpf_prog_type owner_prog_type;
	bool owner_jited;
	union {
		char value[0] __aligned(8);
		void *ptrs[0] __aligned(8);
	};
};
#define MAX_TAIL_CALL_CNT 32

u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
void bpf_fd_array_map_clear(struct bpf_map *map);
bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp);
const struct bpf_func_proto *bpf_get_trace_printk_proto(void);

#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);
void bpf_prog_put_rcu(struct bpf_prog *prog);

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

extern int sysctl_unprivileged_bpf_disabled;

/* 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;
extern const struct bpf_func_proto bpf_tail_call_proto;
extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
extern const struct bpf_func_proto bpf_get_current_comm_proto;
extern const struct bpf_func_proto bpf_skb_vlan_push_proto;
extern const struct bpf_func_proto bpf_skb_vlan_pop_proto;

/* Shared helpers among cBPF and eBPF. */
void bpf_user_rnd_init_once(void);
u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);

#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);
2a36f0b9 WN	27
	28	/* funcs called by prog_array and perf_event_array map */
	29	void (map_fd_get_ptr) (struct bpf_map *map, int fd);
	30	void (map_fd_put_ptr) (void ptr);
99c55f7d AS	31	};
	32
	33	struct bpf_map {
	34	atomic_t refcnt;
	35	enum bpf_map_type map_type;
	36	u32 key_size;
	37	u32 value_size;
	38	u32 max_entries;
aaac3ba9 AS	39	u32 pages;
aaac3ba9 AS	40	struct user_struct *user;
a2c83fff	41	const struct bpf_map_ops *ops;
99c55f7d AS	42	struct work_struct work;
	43	};
	44
	45	struct bpf_map_type_list {
	46	struct list_head list_node;
a2c83fff	47	const struct bpf_map_ops *ops;
99c55f7d AS	48	enum bpf_map_type type;
	49	};
	50
17a52670 AS	51	/* function argument constraints */
17a52670 AS	52	enum bpf_arg_type {
80f1d68c	53	ARG_DONTCARE = 0, /* unused argument in helper function */
17a52670 AS	54
	55	/* the following constraints used to prototype
	56	* bpf_map_lookup/update/delete_elem() functions
	57	*/
	58	ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */
	59	ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */
	60	ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */
	61
	62	/* the following constraints used to prototype bpf_memcmp() and other
	63	* functions that access data on eBPF program stack
	64	*/
	65	ARG_PTR_TO_STACK, /* any pointer to eBPF program stack */
	66	ARG_CONST_STACK_SIZE, /* number of bytes accessed from stack */
80f1d68c	67
608cd71a	68	ARG_PTR_TO_CTX, /* pointer to context */
80f1d68c	69	ARG_ANYTHING, /* any (initialized) argument is ok */
17a52670 AS	70	};
	71
	72	/* type of values returned from helper functions */
	73	enum bpf_return_type {
	74	RET_INTEGER, /* function returns integer */
	75	RET_VOID, /* function doesn't return anything */
	76	RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */
	77	};
	78
09756af4 AS	79	/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
	80	* to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
	81	* instructions after verifying
	82	*/
	83	struct bpf_func_proto {
	84	u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
	85	bool gpl_only;
17a52670 AS	86	enum bpf_return_type ret_type;
	87	enum bpf_arg_type arg1_type;
	88	enum bpf_arg_type arg2_type;
	89	enum bpf_arg_type arg3_type;
	90	enum bpf_arg_type arg4_type;
	91	enum bpf_arg_type arg5_type;
	92	};
	93
	94	/* bpf_context is intentionally undefined structure. Pointer to bpf_context is
	95	* the first argument to eBPF programs.
	96	* For socket filters: 'struct bpf_context ' == 'struct sk_buff '
	97	*/
	98	struct bpf_context;
	99
	100	enum bpf_access_type {
	101	BPF_READ = 1,
	102	BPF_WRITE = 2
09756af4 AS	103	};
09756af4 AS	104
ff936a04 AS	105	struct bpf_prog;
ff936a04 AS	106
09756af4 AS	107	struct bpf_verifier_ops {
	108	/* return eBPF function prototype for verification */
	109	const struct bpf_func_proto (get_func_proto)(enum bpf_func_id func_id);
17a52670 AS	110
	111	/* return true if 'size' wide access at offset 'off' within bpf_context
	112	* with 'type' (read or write) is allowed
	113	*/
	114	bool (*is_valid_access)(int off, int size, enum bpf_access_type type);
9bac3d6d	115
d691f9e8 AS	116	u32 (*convert_ctx_access)(enum bpf_access_type type, int dst_reg,
d691f9e8 AS	117	int src_reg, int ctx_off,
ff936a04	118	struct bpf_insn insn, struct bpf_prog prog);
09756af4 AS	119	};
	120
	121	struct bpf_prog_type_list {
	122	struct list_head list_node;
a2c83fff	123	const struct bpf_verifier_ops *ops;
09756af4 AS	124	enum bpf_prog_type type;
	125	};
	126
09756af4 AS	127	struct bpf_prog_aux {
09756af4 AS	128	atomic_t refcnt;
24701ece	129	u32 used_map_cnt;
a2c83fff	130	const struct bpf_verifier_ops *ops;
09756af4	131	struct bpf_map **used_maps;
09756af4	132	struct bpf_prog *prog;
aaac3ba9	133	struct user_struct *user;
abf2e7d6 AS	134	union {
	135	struct work_struct work;
	136	struct rcu_head rcu;
	137	};
09756af4 AS	138	};
09756af4 AS	139
04fd61ab AS	140	struct bpf_array {
	141	struct bpf_map map;
	142	u32 elem_size;
	143	/* 'ownership' of prog_array is claimed by the first program that
	144	* is going to use this map or by the first program which FD is stored
	145	* in the map to make sure that all callers and callees have the same
	146	* prog_type and JITed flag
	147	*/
	148	enum bpf_prog_type owner_prog_type;
	149	bool owner_jited;
	150	union {
	151	char value[0] __aligned(8);
2a36f0b9	152	void *ptrs[0] __aligned(8);
04fd61ab AS	153	};
	154	};
	155	#define MAX_TAIL_CALL_CNT 32
	156
	157	u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
2a36f0b9	158	void bpf_fd_array_map_clear(struct bpf_map *map);
04fd61ab	159	bool bpf_prog_array_compatible(struct bpf_array array, const struct bpf_prog fp);
0756ea3e	160	const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
04fd61ab	161
89aa0758	162	#ifdef CONFIG_BPF_SYSCALL
0fc174de	163	void bpf_register_prog_type(struct bpf_prog_type_list *tl);
61e021f3	164	void bpf_register_map_type(struct bpf_map_type_list *tl);
0fc174de	165
0fc174de	166	struct bpf_prog *bpf_prog_get(u32 ufd);
61e021f3	167	void bpf_prog_put(struct bpf_prog *prog);
abf2e7d6	168	void bpf_prog_put_rcu(struct bpf_prog *prog);
61e021f3 DB	169
	170	struct bpf_map *bpf_map_get(struct fd f);
	171	void bpf_map_put(struct bpf_map *map);
	172
1be7f75d AS	173	extern int sysctl_unprivileged_bpf_disabled;
1be7f75d AS	174
61e021f3	175	/* verify correctness of eBPF program */
9bac3d6d	176	int bpf_check(struct bpf_prog *fp, union bpf_attr attr);
89aa0758	177	#else
0fc174de DB	178	static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl)
	179	{
	180	}
	181
	182	static inline struct bpf_prog *bpf_prog_get(u32 ufd)
	183	{
	184	return ERR_PTR(-EOPNOTSUPP);
	185	}
	186
	187	static inline void bpf_prog_put(struct bpf_prog *prog)
	188	{
	189	}
61e021f3	190	#endif /* CONFIG_BPF_SYSCALL */
09756af4	191
d0003ec0	192	/* verifier prototypes for helper functions called from eBPF programs */
a2c83fff DB	193	extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
	194	extern const struct bpf_func_proto bpf_map_update_elem_proto;
	195	extern const struct bpf_func_proto bpf_map_delete_elem_proto;
d0003ec0	196
03e69b50	197	extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
c04167ce	198	extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
04fd61ab	199	extern const struct bpf_func_proto bpf_tail_call_proto;
17ca8cbf	200	extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
ffeedafb AS	201	extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
	202	extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
	203	extern const struct bpf_func_proto bpf_get_current_comm_proto;
4e10df9a AS	204	extern const struct bpf_func_proto bpf_skb_vlan_push_proto;
4e10df9a AS	205	extern const struct bpf_func_proto bpf_skb_vlan_pop_proto;
03e69b50	206
3ad00405 DB	207	/* Shared helpers among cBPF and eBPF. */
	208	void bpf_user_rnd_init_once(void);
	209	u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
	210
99c55f7d	211	#endif /* _LINUX_BPF_H */