[mirror_ubuntu-bionic-kernel.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>
#include <linux/percpu.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 map_flags;
	u32 pages;
	struct user_struct *user;
	const struct bpf_map_ops *ops;
	struct work_struct work;
	atomic_t usercnt;
};

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_CONST_STACK_SIZE_OR_ZERO, /* number of bytes accessed from stack or 0 */

	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;
	u32 max_ctx_offset;
	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);
		void __percpu *pptrs[0] __aligned(8);
	};
};
#define MAX_TAIL_CALL_CNT 32

u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, 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
DECLARE_PER_CPU(int, bpf_prog_active);

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_with_uref(u32 ufd);
struct bpf_map *__bpf_map_get(struct fd f);
void bpf_map_inc(struct bpf_map *map, bool uref);
void bpf_map_put_with_uref(struct bpf_map *map);
void bpf_map_put(struct bpf_map *map);
int bpf_map_precharge_memlock(u32 pages);

extern int sysctl_unprivileged_bpf_disabled;

int bpf_map_new_fd(struct bpf_map *map);
int bpf_prog_new_fd(struct bpf_prog *prog);

int bpf_obj_pin_user(u32 ufd, const char __user *pathname);
int bpf_obj_get_user(const char __user *pathname);

int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value);
int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value);
int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
			   u64 flags);
int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
			    u64 flags);
int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value);

/* memcpy that is used with 8-byte aligned pointers, power-of-8 size and
 * forced to use 'long' read/writes to try to atomically copy long counters.
 * Best-effort only.  No barriers here, since it _will_ race with concurrent
 * updates from BPF programs. Called from bpf syscall and mostly used with
 * size 8 or 16 bytes, so ask compiler to inline it.
 */
static inline void bpf_long_memcpy(void *dst, const void *src, u32 size)
{
	const long *lsrc = src;
	long *ldst = dst;

	size /= sizeof(long);
	while (size--)
		*ldst++ = *lsrc++;
}

/* 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;
extern const struct bpf_func_proto bpf_get_stackid_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>
b121d1e7	13	#include <linux/percpu.h>
99c55f7d AS	14
	15	struct bpf_map;
	16
	17	/* map is generic key/value storage optionally accesible by eBPF programs */
	18	struct bpf_map_ops {
	19	/* funcs callable from userspace (via syscall) */
	20	struct bpf_map (map_alloc)(union bpf_attr *attr);
	21	void (map_free)(struct bpf_map );
db20fd2b AS	22	int (map_get_next_key)(struct bpf_map map, void key, void next_key);
	23
	24	/* funcs callable from userspace and from eBPF programs */
	25	void (map_lookup_elem)(struct bpf_map map, void key);
3274f520	26	int (map_update_elem)(struct bpf_map map, void key, void value, u64 flags);
db20fd2b	27	int (map_delete_elem)(struct bpf_map map, void *key);
2a36f0b9 WN	28
	29	/* funcs called by prog_array and perf_event_array map */
	30	void (map_fd_get_ptr) (struct bpf_map *map, int fd);
	31	void (map_fd_put_ptr) (void ptr);
99c55f7d AS	32	};
	33
	34	struct bpf_map {
	35	atomic_t refcnt;
	36	enum bpf_map_type map_type;
	37	u32 key_size;
	38	u32 value_size;
	39	u32 max_entries;
6c905981	40	u32 map_flags;
aaac3ba9 AS	41	u32 pages;
aaac3ba9 AS	42	struct user_struct *user;
a2c83fff	43	const struct bpf_map_ops *ops;
99c55f7d	44	struct work_struct work;
c9da161c	45	atomic_t usercnt;
99c55f7d AS	46	};
	47
	48	struct bpf_map_type_list {
	49	struct list_head list_node;
a2c83fff	50	const struct bpf_map_ops *ops;
99c55f7d AS	51	enum bpf_map_type type;
	52	};
	53
17a52670 AS	54	/* function argument constraints */
17a52670 AS	55	enum bpf_arg_type {
80f1d68c	56	ARG_DONTCARE = 0, /* unused argument in helper function */
17a52670 AS	57
	58	/* the following constraints used to prototype
	59	* bpf_map_lookup/update/delete_elem() functions
	60	*/
	61	ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */
	62	ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */
	63	ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */
	64
	65	/* the following constraints used to prototype bpf_memcmp() and other
	66	* functions that access data on eBPF program stack
	67	*/
	68	ARG_PTR_TO_STACK, /* any pointer to eBPF program stack */
	69	ARG_CONST_STACK_SIZE, /* number of bytes accessed from stack */
8e2fe1d9	70	ARG_CONST_STACK_SIZE_OR_ZERO, /* number of bytes accessed from stack or 0 */
80f1d68c	71
608cd71a	72	ARG_PTR_TO_CTX, /* pointer to context */
80f1d68c	73	ARG_ANYTHING, /* any (initialized) argument is ok */
17a52670 AS	74	};
	75
	76	/* type of values returned from helper functions */
	77	enum bpf_return_type {
	78	RET_INTEGER, /* function returns integer */
	79	RET_VOID, /* function doesn't return anything */
	80	RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */
	81	};
	82
09756af4 AS	83	/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
	84	* to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
	85	* instructions after verifying
	86	*/
	87	struct bpf_func_proto {
	88	u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
	89	bool gpl_only;
17a52670 AS	90	enum bpf_return_type ret_type;
	91	enum bpf_arg_type arg1_type;
	92	enum bpf_arg_type arg2_type;
	93	enum bpf_arg_type arg3_type;
	94	enum bpf_arg_type arg4_type;
	95	enum bpf_arg_type arg5_type;
	96	};
	97
	98	/* bpf_context is intentionally undefined structure. Pointer to bpf_context is
	99	* the first argument to eBPF programs.
	100	* For socket filters: 'struct bpf_context ' == 'struct sk_buff '
	101	*/
	102	struct bpf_context;
	103
	104	enum bpf_access_type {
	105	BPF_READ = 1,
	106	BPF_WRITE = 2
09756af4 AS	107	};
09756af4 AS	108
ff936a04 AS	109	struct bpf_prog;
ff936a04 AS	110
09756af4 AS	111	struct bpf_verifier_ops {
	112	/* return eBPF function prototype for verification */
	113	const struct bpf_func_proto (get_func_proto)(enum bpf_func_id func_id);
17a52670 AS	114
	115	/* return true if 'size' wide access at offset 'off' within bpf_context
	116	* with 'type' (read or write) is allowed
	117	*/
	118	bool (*is_valid_access)(int off, int size, enum bpf_access_type type);
9bac3d6d	119
d691f9e8 AS	120	u32 (*convert_ctx_access)(enum bpf_access_type type, int dst_reg,
d691f9e8 AS	121	int src_reg, int ctx_off,
ff936a04	122	struct bpf_insn insn, struct bpf_prog prog);
09756af4 AS	123	};
	124
	125	struct bpf_prog_type_list {
	126	struct list_head list_node;
a2c83fff	127	const struct bpf_verifier_ops *ops;
09756af4 AS	128	enum bpf_prog_type type;
	129	};
	130
09756af4 AS	131	struct bpf_prog_aux {
09756af4 AS	132	atomic_t refcnt;
24701ece	133	u32 used_map_cnt;
32bbe007	134	u32 max_ctx_offset;
a2c83fff	135	const struct bpf_verifier_ops *ops;
09756af4	136	struct bpf_map **used_maps;
09756af4	137	struct bpf_prog *prog;
aaac3ba9	138	struct user_struct *user;
abf2e7d6 AS	139	union {
	140	struct work_struct work;
	141	struct rcu_head rcu;
	142	};
09756af4 AS	143	};
09756af4 AS	144
04fd61ab AS	145	struct bpf_array {
	146	struct bpf_map map;
	147	u32 elem_size;
	148	/* 'ownership' of prog_array is claimed by the first program that
	149	* is going to use this map or by the first program which FD is stored
	150	* in the map to make sure that all callers and callees have the same
	151	* prog_type and JITed flag
	152	*/
	153	enum bpf_prog_type owner_prog_type;
	154	bool owner_jited;
	155	union {
	156	char value[0] __aligned(8);
2a36f0b9	157	void *ptrs[0] __aligned(8);
a10423b8	158	void __percpu *pptrs[0] __aligned(8);
04fd61ab AS	159	};
	160	};
	161	#define MAX_TAIL_CALL_CNT 32
	162
	163	u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
9940d67c	164	u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
2a36f0b9	165	void bpf_fd_array_map_clear(struct bpf_map *map);
04fd61ab	166	bool bpf_prog_array_compatible(struct bpf_array array, const struct bpf_prog fp);
0756ea3e	167	const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
04fd61ab	168
89aa0758	169	#ifdef CONFIG_BPF_SYSCALL
b121d1e7 AS	170	DECLARE_PER_CPU(int, bpf_prog_active);
b121d1e7 AS	171
0fc174de	172	void bpf_register_prog_type(struct bpf_prog_type_list *tl);
61e021f3	173	void bpf_register_map_type(struct bpf_map_type_list *tl);
0fc174de	174
0fc174de	175	struct bpf_prog *bpf_prog_get(u32 ufd);
61e021f3	176	void bpf_prog_put(struct bpf_prog *prog);
abf2e7d6	177	void bpf_prog_put_rcu(struct bpf_prog *prog);
61e021f3	178
c9da161c	179	struct bpf_map *bpf_map_get_with_uref(u32 ufd);
c2101297	180	struct bpf_map *__bpf_map_get(struct fd f);
c9da161c DB	181	void bpf_map_inc(struct bpf_map *map, bool uref);
c9da161c DB	182	void bpf_map_put_with_uref(struct bpf_map *map);
61e021f3	183	void bpf_map_put(struct bpf_map *map);
6c905981	184	int bpf_map_precharge_memlock(u32 pages);
61e021f3	185
1be7f75d AS	186	extern int sysctl_unprivileged_bpf_disabled;
1be7f75d AS	187
b2197755 DB	188	int bpf_map_new_fd(struct bpf_map *map);
	189	int bpf_prog_new_fd(struct bpf_prog *prog);
	190
	191	int bpf_obj_pin_user(u32 ufd, const char __user *pathname);
	192	int bpf_obj_get_user(const char __user *pathname);
	193
15a07b33 AS	194	int bpf_percpu_hash_copy(struct bpf_map map, void key, void *value);
	195	int bpf_percpu_array_copy(struct bpf_map map, void key, void *value);
	196	int bpf_percpu_hash_update(struct bpf_map map, void key, void *value,
	197	u64 flags);
	198	int bpf_percpu_array_update(struct bpf_map map, void key, void *value,
	199	u64 flags);
557c0c6e	200	int bpf_stackmap_copy(struct bpf_map map, void key, void *value);
15a07b33 AS	201
	202	/* memcpy that is used with 8-byte aligned pointers, power-of-8 size and
	203	* forced to use 'long' read/writes to try to atomically copy long counters.
	204	* Best-effort only. No barriers here, since it _will_ race with concurrent
	205	* updates from BPF programs. Called from bpf syscall and mostly used with
	206	* size 8 or 16 bytes, so ask compiler to inline it.
	207	*/
	208	static inline void bpf_long_memcpy(void dst, const void src, u32 size)
	209	{
	210	const long *lsrc = src;
	211	long *ldst = dst;
	212
	213	size /= sizeof(long);
	214	while (size--)
	215	ldst++ = lsrc++;
	216	}
	217
61e021f3	218	/* verify correctness of eBPF program */
9bac3d6d	219	int bpf_check(struct bpf_prog *fp, union bpf_attr attr);
89aa0758	220	#else
0fc174de DB	221	static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl)
	222	{
	223	}
	224
	225	static inline struct bpf_prog *bpf_prog_get(u32 ufd)
	226	{
	227	return ERR_PTR(-EOPNOTSUPP);
	228	}
	229
	230	static inline void bpf_prog_put(struct bpf_prog *prog)
	231	{
	232	}
61e021f3	233	#endif /* CONFIG_BPF_SYSCALL */
09756af4	234
d0003ec0	235	/* verifier prototypes for helper functions called from eBPF programs */
a2c83fff DB	236	extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
	237	extern const struct bpf_func_proto bpf_map_update_elem_proto;
	238	extern const struct bpf_func_proto bpf_map_delete_elem_proto;
d0003ec0	239
03e69b50	240	extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
c04167ce	241	extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
04fd61ab	242	extern const struct bpf_func_proto bpf_tail_call_proto;
17ca8cbf	243	extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
ffeedafb AS	244	extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
	245	extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
	246	extern const struct bpf_func_proto bpf_get_current_comm_proto;
4e10df9a AS	247	extern const struct bpf_func_proto bpf_skb_vlan_push_proto;
4e10df9a AS	248	extern const struct bpf_func_proto bpf_skb_vlan_pop_proto;
d5a3b1f6	249	extern const struct bpf_func_proto bpf_get_stackid_proto;
03e69b50	250
3ad00405 DB	251	/* Shared helpers among cBPF and eBPF. */
	252	void bpf_user_rnd_init_once(void);
	253	u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
	254
99c55f7d	255	#endif /* _LINUX_BPF_H */