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>
13 #include <linux/percpu.h>
17 /* map is generic key/value storage optionally accesible by eBPF programs */
19 /* funcs callable from userspace (via syscall) */
20 struct bpf_map
*(*map_alloc
)(union bpf_attr
*attr
);
21 void (*map_free
)(struct bpf_map
*);
22 int (*map_get_next_key
)(struct bpf_map
*map
, void *key
, void *next_key
);
24 /* funcs callable from userspace and from eBPF programs */
25 void *(*map_lookup_elem
)(struct bpf_map
*map
, void *key
);
26 int (*map_update_elem
)(struct bpf_map
*map
, void *key
, void *value
, u64 flags
);
27 int (*map_delete_elem
)(struct bpf_map
*map
, void *key
);
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
);
36 enum bpf_map_type map_type
;
42 struct user_struct
*user
;
43 const struct bpf_map_ops
*ops
;
44 struct work_struct work
;
48 struct bpf_map_type_list
{
49 struct list_head list_node
;
50 const struct bpf_map_ops
*ops
;
51 enum bpf_map_type type
;
54 /* function argument constraints */
56 ARG_DONTCARE
= 0, /* unused argument in helper function */
58 /* the following constraints used to prototype
59 * bpf_map_lookup/update/delete_elem() functions
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 */
65 /* the following constraints used to prototype bpf_memcmp() and other
66 * functions that access data on eBPF program stack
68 ARG_PTR_TO_STACK
, /* any pointer to eBPF program stack */
69 ARG_PTR_TO_RAW_STACK
, /* any pointer to eBPF program stack, area does not
70 * need to be initialized, helper function must fill
71 * all bytes or clear them in error case.
74 ARG_CONST_STACK_SIZE
, /* number of bytes accessed from stack */
75 ARG_CONST_STACK_SIZE_OR_ZERO
, /* number of bytes accessed from stack or 0 */
77 ARG_PTR_TO_CTX
, /* pointer to context */
78 ARG_ANYTHING
, /* any (initialized) argument is ok */
81 /* type of values returned from helper functions */
82 enum bpf_return_type
{
83 RET_INTEGER
, /* function returns integer */
84 RET_VOID
, /* function doesn't return anything */
85 RET_PTR_TO_MAP_VALUE_OR_NULL
, /* returns a pointer to map elem value or NULL */
88 /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
89 * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
90 * instructions after verifying
92 struct bpf_func_proto
{
93 u64 (*func
)(u64 r1
, u64 r2
, u64 r3
, u64 r4
, u64 r5
);
95 enum bpf_return_type ret_type
;
96 enum bpf_arg_type arg1_type
;
97 enum bpf_arg_type arg2_type
;
98 enum bpf_arg_type arg3_type
;
99 enum bpf_arg_type arg4_type
;
100 enum bpf_arg_type arg5_type
;
103 /* bpf_context is intentionally undefined structure. Pointer to bpf_context is
104 * the first argument to eBPF programs.
105 * For socket filters: 'struct bpf_context *' == 'struct sk_buff *'
109 enum bpf_access_type
{
114 /* types of values stored in eBPF registers */
116 NOT_INIT
= 0, /* nothing was written into register */
117 UNKNOWN_VALUE
, /* reg doesn't contain a valid pointer */
118 PTR_TO_CTX
, /* reg points to bpf_context */
119 CONST_PTR_TO_MAP
, /* reg points to struct bpf_map */
120 PTR_TO_MAP_VALUE
, /* reg points to map element value */
121 PTR_TO_MAP_VALUE_OR_NULL
,/* points to map elem value or NULL */
122 FRAME_PTR
, /* reg == frame_pointer */
123 PTR_TO_STACK
, /* reg == frame_pointer + imm */
124 CONST_IMM
, /* constant integer value */
126 /* PTR_TO_PACKET represents:
129 * skb->data + (u16) var
130 * skb->data + (u16) var + imm
131 * if (range > 0) then [ptr, ptr + range - off) is safe to access
132 * if (id > 0) means that some 'var' was added
133 * if (off > 0) menas that 'imm' was added
136 PTR_TO_PACKET_END
, /* skb->data + headlen */
141 struct bpf_verifier_ops
{
142 /* return eBPF function prototype for verification */
143 const struct bpf_func_proto
*(*get_func_proto
)(enum bpf_func_id func_id
);
145 /* return true if 'size' wide access at offset 'off' within bpf_context
146 * with 'type' (read or write) is allowed
148 bool (*is_valid_access
)(int off
, int size
, enum bpf_access_type type
,
149 enum bpf_reg_type
*reg_type
);
151 u32 (*convert_ctx_access
)(enum bpf_access_type type
, int dst_reg
,
152 int src_reg
, int ctx_off
,
153 struct bpf_insn
*insn
, struct bpf_prog
*prog
);
156 struct bpf_prog_type_list
{
157 struct list_head list_node
;
158 const struct bpf_verifier_ops
*ops
;
159 enum bpf_prog_type type
;
162 struct bpf_prog_aux
{
166 const struct bpf_verifier_ops
*ops
;
167 struct bpf_map
**used_maps
;
168 struct bpf_prog
*prog
;
169 struct user_struct
*user
;
171 struct work_struct work
;
179 /* 'ownership' of prog_array is claimed by the first program that
180 * is going to use this map or by the first program which FD is stored
181 * in the map to make sure that all callers and callees have the same
182 * prog_type and JITed flag
184 enum bpf_prog_type owner_prog_type
;
187 char value
[0] __aligned(8);
188 void *ptrs
[0] __aligned(8);
189 void __percpu
*pptrs
[0] __aligned(8);
192 #define MAX_TAIL_CALL_CNT 32
194 u64
bpf_tail_call(u64 ctx
, u64 r2
, u64 index
, u64 r4
, u64 r5
);
195 u64
bpf_get_stackid(u64 r1
, u64 r2
, u64 r3
, u64 r4
, u64 r5
);
196 void bpf_fd_array_map_clear(struct bpf_map
*map
);
197 bool bpf_prog_array_compatible(struct bpf_array
*array
, const struct bpf_prog
*fp
);
199 const struct bpf_func_proto
*bpf_get_trace_printk_proto(void);
200 const struct bpf_func_proto
*bpf_get_event_output_proto(void);
202 #ifdef CONFIG_BPF_SYSCALL
203 DECLARE_PER_CPU(int, bpf_prog_active
);
205 void bpf_register_prog_type(struct bpf_prog_type_list
*tl
);
206 void bpf_register_map_type(struct bpf_map_type_list
*tl
);
208 struct bpf_prog
*bpf_prog_get(u32 ufd
);
209 struct bpf_prog
*bpf_prog_inc(struct bpf_prog
*prog
);
210 void bpf_prog_put(struct bpf_prog
*prog
);
211 void bpf_prog_put_rcu(struct bpf_prog
*prog
);
213 struct bpf_map
*bpf_map_get_with_uref(u32 ufd
);
214 struct bpf_map
*__bpf_map_get(struct fd f
);
215 struct bpf_map
*bpf_map_inc(struct bpf_map
*map
, bool uref
);
216 void bpf_map_put_with_uref(struct bpf_map
*map
);
217 void bpf_map_put(struct bpf_map
*map
);
218 int bpf_map_precharge_memlock(u32 pages
);
220 extern int sysctl_unprivileged_bpf_disabled
;
222 int bpf_map_new_fd(struct bpf_map
*map
);
223 int bpf_prog_new_fd(struct bpf_prog
*prog
);
225 int bpf_obj_pin_user(u32 ufd
, const char __user
*pathname
);
226 int bpf_obj_get_user(const char __user
*pathname
);
228 int bpf_percpu_hash_copy(struct bpf_map
*map
, void *key
, void *value
);
229 int bpf_percpu_array_copy(struct bpf_map
*map
, void *key
, void *value
);
230 int bpf_percpu_hash_update(struct bpf_map
*map
, void *key
, void *value
,
232 int bpf_percpu_array_update(struct bpf_map
*map
, void *key
, void *value
,
234 int bpf_stackmap_copy(struct bpf_map
*map
, void *key
, void *value
);
236 /* memcpy that is used with 8-byte aligned pointers, power-of-8 size and
237 * forced to use 'long' read/writes to try to atomically copy long counters.
238 * Best-effort only. No barriers here, since it _will_ race with concurrent
239 * updates from BPF programs. Called from bpf syscall and mostly used with
240 * size 8 or 16 bytes, so ask compiler to inline it.
242 static inline void bpf_long_memcpy(void *dst
, const void *src
, u32 size
)
244 const long *lsrc
= src
;
247 size
/= sizeof(long);
252 /* verify correctness of eBPF program */
253 int bpf_check(struct bpf_prog
**fp
, union bpf_attr
*attr
);
255 static inline void bpf_register_prog_type(struct bpf_prog_type_list
*tl
)
259 static inline struct bpf_prog
*bpf_prog_get(u32 ufd
)
261 return ERR_PTR(-EOPNOTSUPP
);
264 static inline void bpf_prog_put(struct bpf_prog
*prog
)
268 static inline void bpf_prog_put_rcu(struct bpf_prog
*prog
)
271 #endif /* CONFIG_BPF_SYSCALL */
273 /* verifier prototypes for helper functions called from eBPF programs */
274 extern const struct bpf_func_proto bpf_map_lookup_elem_proto
;
275 extern const struct bpf_func_proto bpf_map_update_elem_proto
;
276 extern const struct bpf_func_proto bpf_map_delete_elem_proto
;
278 extern const struct bpf_func_proto bpf_get_prandom_u32_proto
;
279 extern const struct bpf_func_proto bpf_get_smp_processor_id_proto
;
280 extern const struct bpf_func_proto bpf_tail_call_proto
;
281 extern const struct bpf_func_proto bpf_ktime_get_ns_proto
;
282 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto
;
283 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto
;
284 extern const struct bpf_func_proto bpf_get_current_comm_proto
;
285 extern const struct bpf_func_proto bpf_skb_vlan_push_proto
;
286 extern const struct bpf_func_proto bpf_skb_vlan_pop_proto
;
287 extern const struct bpf_func_proto bpf_get_stackid_proto
;
289 /* Shared helpers among cBPF and eBPF. */
290 void bpf_user_rnd_init_once(void);
291 u64
bpf_user_rnd_u32(u64 r1
, u64 r2
, u64 r3
, u64 r4
, u64 r5
);
293 #endif /* _LINUX_BPF_H */