bpf: possibly avoid extra masking for narrower load in verifier
[linux-2.6-block.git] / include / linux / bpf.h
CommitLineData
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>
74451e66 11
99c55f7d 12#include <linux/workqueue.h>
db20fd2b 13#include <linux/file.h>
b121d1e7 14#include <linux/percpu.h>
002245cc 15#include <linux/err.h>
74451e66 16#include <linux/rbtree_latch.h>
99c55f7d 17
3b1efb19 18struct perf_event;
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AS
19struct bpf_map;
20
21/* map is generic key/value storage optionally accesible by eBPF programs */
22struct bpf_map_ops {
23 /* funcs callable from userspace (via syscall) */
24 struct bpf_map *(*map_alloc)(union bpf_attr *attr);
61d1b6a4
DB
25 void (*map_release)(struct bpf_map *map, struct file *map_file);
26 void (*map_free)(struct bpf_map *map);
db20fd2b
AS
27 int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key);
28
29 /* funcs callable from userspace and from eBPF programs */
30 void *(*map_lookup_elem)(struct bpf_map *map, void *key);
3274f520 31 int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags);
db20fd2b 32 int (*map_delete_elem)(struct bpf_map *map, void *key);
2a36f0b9
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33
34 /* funcs called by prog_array and perf_event_array map */
d056a788
DB
35 void *(*map_fd_get_ptr)(struct bpf_map *map, struct file *map_file,
36 int fd);
37 void (*map_fd_put_ptr)(void *ptr);
81ed18ab 38 u32 (*map_gen_lookup)(struct bpf_map *map, struct bpf_insn *insn_buf);
99c55f7d
AS
39};
40
41struct bpf_map {
42 atomic_t refcnt;
43 enum bpf_map_type map_type;
44 u32 key_size;
45 u32 value_size;
46 u32 max_entries;
6c905981 47 u32 map_flags;
aaac3ba9 48 u32 pages;
f3f1c054 49 u32 id;
aaac3ba9 50 struct user_struct *user;
a2c83fff 51 const struct bpf_map_ops *ops;
99c55f7d 52 struct work_struct work;
c9da161c 53 atomic_t usercnt;
56f668df 54 struct bpf_map *inner_map_meta;
99c55f7d
AS
55};
56
17a52670
AS
57/* function argument constraints */
58enum bpf_arg_type {
80f1d68c 59 ARG_DONTCARE = 0, /* unused argument in helper function */
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60
61 /* the following constraints used to prototype
62 * bpf_map_lookup/update/delete_elem() functions
63 */
64 ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */
65 ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */
66 ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */
67
68 /* the following constraints used to prototype bpf_memcmp() and other
69 * functions that access data on eBPF program stack
70 */
39f19ebb
AS
71 ARG_PTR_TO_MEM, /* pointer to valid memory (stack, packet, map value) */
72 ARG_PTR_TO_UNINIT_MEM, /* pointer to memory does not need to be initialized,
73 * helper function must fill all bytes or clear
74 * them in error case.
435faee1
DB
75 */
76
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AS
77 ARG_CONST_SIZE, /* number of bytes accessed from memory */
78 ARG_CONST_SIZE_OR_ZERO, /* number of bytes accessed from memory or 0 */
80f1d68c 79
608cd71a 80 ARG_PTR_TO_CTX, /* pointer to context */
80f1d68c 81 ARG_ANYTHING, /* any (initialized) argument is ok */
17a52670
AS
82};
83
84/* type of values returned from helper functions */
85enum bpf_return_type {
86 RET_INTEGER, /* function returns integer */
87 RET_VOID, /* function doesn't return anything */
88 RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */
89};
90
09756af4
AS
91/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
92 * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
93 * instructions after verifying
94 */
95struct bpf_func_proto {
96 u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
97 bool gpl_only;
36bbef52 98 bool pkt_access;
17a52670
AS
99 enum bpf_return_type ret_type;
100 enum bpf_arg_type arg1_type;
101 enum bpf_arg_type arg2_type;
102 enum bpf_arg_type arg3_type;
103 enum bpf_arg_type arg4_type;
104 enum bpf_arg_type arg5_type;
105};
106
107/* bpf_context is intentionally undefined structure. Pointer to bpf_context is
108 * the first argument to eBPF programs.
109 * For socket filters: 'struct bpf_context *' == 'struct sk_buff *'
110 */
111struct bpf_context;
112
113enum bpf_access_type {
114 BPF_READ = 1,
115 BPF_WRITE = 2
09756af4
AS
116};
117
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118/* types of values stored in eBPF registers */
119enum bpf_reg_type {
120 NOT_INIT = 0, /* nothing was written into register */
121 UNKNOWN_VALUE, /* reg doesn't contain a valid pointer */
122 PTR_TO_CTX, /* reg points to bpf_context */
123 CONST_PTR_TO_MAP, /* reg points to struct bpf_map */
124 PTR_TO_MAP_VALUE, /* reg points to map element value */
125 PTR_TO_MAP_VALUE_OR_NULL,/* points to map elem value or NULL */
126 FRAME_PTR, /* reg == frame_pointer */
127 PTR_TO_STACK, /* reg == frame_pointer + imm */
128 CONST_IMM, /* constant integer value */
129
130 /* PTR_TO_PACKET represents:
131 * skb->data
132 * skb->data + imm
133 * skb->data + (u16) var
134 * skb->data + (u16) var + imm
135 * if (range > 0) then [ptr, ptr + range - off) is safe to access
136 * if (id > 0) means that some 'var' was added
137 * if (off > 0) menas that 'imm' was added
138 */
139 PTR_TO_PACKET,
140 PTR_TO_PACKET_END, /* skb->data + headlen */
48461135
JB
141
142 /* PTR_TO_MAP_VALUE_ADJ is used for doing pointer math inside of a map
143 * elem value. We only allow this if we can statically verify that
144 * access from this register are going to fall within the size of the
145 * map element.
146 */
147 PTR_TO_MAP_VALUE_ADJ,
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AS
148};
149
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AS
150struct bpf_prog;
151
23994631
YS
152/* The information passed from prog-specific *_is_valid_access
153 * back to the verifier.
154 */
155struct bpf_insn_access_aux {
156 enum bpf_reg_type reg_type;
157 int ctx_field_size;
158 int converted_op_size;
159};
160
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161struct bpf_verifier_ops {
162 /* return eBPF function prototype for verification */
163 const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id);
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164
165 /* return true if 'size' wide access at offset 'off' within bpf_context
166 * with 'type' (read or write) is allowed
167 */
19de99f7 168 bool (*is_valid_access)(int off, int size, enum bpf_access_type type,
23994631 169 struct bpf_insn_access_aux *info);
36bbef52
DB
170 int (*gen_prologue)(struct bpf_insn *insn, bool direct_write,
171 const struct bpf_prog *prog);
6b8cc1d1
DB
172 u32 (*convert_ctx_access)(enum bpf_access_type type,
173 const struct bpf_insn *src,
174 struct bpf_insn *dst,
175 struct bpf_prog *prog);
1cf1cae9
AS
176 int (*test_run)(struct bpf_prog *prog, const union bpf_attr *kattr,
177 union bpf_attr __user *uattr);
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178};
179
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180struct bpf_prog_aux {
181 atomic_t refcnt;
24701ece 182 u32 used_map_cnt;
32bbe007 183 u32 max_ctx_offset;
8726679a 184 u32 stack_depth;
dc4bb0e2 185 u32 id;
74451e66
DB
186 struct latch_tree_node ksym_tnode;
187 struct list_head ksym_lnode;
a2c83fff 188 const struct bpf_verifier_ops *ops;
09756af4 189 struct bpf_map **used_maps;
09756af4 190 struct bpf_prog *prog;
aaac3ba9 191 struct user_struct *user;
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192 union {
193 struct work_struct work;
194 struct rcu_head rcu;
195 };
09756af4
AS
196};
197
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AS
198struct bpf_array {
199 struct bpf_map map;
200 u32 elem_size;
201 /* 'ownership' of prog_array is claimed by the first program that
202 * is going to use this map or by the first program which FD is stored
203 * in the map to make sure that all callers and callees have the same
204 * prog_type and JITed flag
205 */
206 enum bpf_prog_type owner_prog_type;
207 bool owner_jited;
208 union {
209 char value[0] __aligned(8);
2a36f0b9 210 void *ptrs[0] __aligned(8);
a10423b8 211 void __percpu *pptrs[0] __aligned(8);
04fd61ab
AS
212 };
213};
3b1efb19 214
04fd61ab
AS
215#define MAX_TAIL_CALL_CNT 32
216
3b1efb19
DB
217struct bpf_event_entry {
218 struct perf_event *event;
219 struct file *perf_file;
220 struct file *map_file;
221 struct rcu_head rcu;
222};
223
04fd61ab 224u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
9940d67c 225u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
d056a788 226
04fd61ab 227bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp);
f1f7714e 228int bpf_prog_calc_tag(struct bpf_prog *fp);
bd570ff9 229
0756ea3e 230const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
555c8a86
DB
231
232typedef unsigned long (*bpf_ctx_copy_t)(void *dst, const void *src,
aa7145c1 233 unsigned long off, unsigned long len);
555c8a86
DB
234
235u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
236 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy);
04fd61ab 237
1cf1cae9
AS
238int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
239 union bpf_attr __user *uattr);
240int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
241 union bpf_attr __user *uattr);
242
89aa0758 243#ifdef CONFIG_BPF_SYSCALL
b121d1e7
AS
244DECLARE_PER_CPU(int, bpf_prog_active);
245
be9370a7
JB
246#define BPF_PROG_TYPE(_id, _ops) \
247 extern const struct bpf_verifier_ops _ops;
40077e0c
JB
248#define BPF_MAP_TYPE(_id, _ops) \
249 extern const struct bpf_map_ops _ops;
be9370a7
JB
250#include <linux/bpf_types.h>
251#undef BPF_PROG_TYPE
40077e0c 252#undef BPF_MAP_TYPE
0fc174de 253
0fc174de 254struct bpf_prog *bpf_prog_get(u32 ufd);
113214be 255struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type);
6d67942d 256struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, int i);
c540594f 257void bpf_prog_sub(struct bpf_prog *prog, int i);
6d67942d 258struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog);
61e021f3 259void bpf_prog_put(struct bpf_prog *prog);
5ccb071e
DB
260int __bpf_prog_charge(struct user_struct *user, u32 pages);
261void __bpf_prog_uncharge(struct user_struct *user, u32 pages);
61e021f3 262
c9da161c 263struct bpf_map *bpf_map_get_with_uref(u32 ufd);
c2101297 264struct bpf_map *__bpf_map_get(struct fd f);
6d67942d 265struct bpf_map * __must_check bpf_map_inc(struct bpf_map *map, bool uref);
c9da161c 266void bpf_map_put_with_uref(struct bpf_map *map);
61e021f3 267void bpf_map_put(struct bpf_map *map);
6c905981 268int bpf_map_precharge_memlock(u32 pages);
d407bd25
DB
269void *bpf_map_area_alloc(size_t size);
270void bpf_map_area_free(void *base);
61e021f3 271
1be7f75d
AS
272extern int sysctl_unprivileged_bpf_disabled;
273
b2197755
DB
274int bpf_map_new_fd(struct bpf_map *map);
275int bpf_prog_new_fd(struct bpf_prog *prog);
276
277int bpf_obj_pin_user(u32 ufd, const char __user *pathname);
278int bpf_obj_get_user(const char __user *pathname);
279
15a07b33
AS
280int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value);
281int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value);
282int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
283 u64 flags);
284int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
285 u64 flags);
d056a788 286
557c0c6e 287int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value);
15a07b33 288
d056a788
DB
289int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
290 void *key, void *value, u64 map_flags);
291void bpf_fd_array_map_clear(struct bpf_map *map);
bcc6b1b7
MKL
292int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file,
293 void *key, void *value, u64 map_flags);
d056a788 294
15a07b33
AS
295/* memcpy that is used with 8-byte aligned pointers, power-of-8 size and
296 * forced to use 'long' read/writes to try to atomically copy long counters.
297 * Best-effort only. No barriers here, since it _will_ race with concurrent
298 * updates from BPF programs. Called from bpf syscall and mostly used with
299 * size 8 or 16 bytes, so ask compiler to inline it.
300 */
301static inline void bpf_long_memcpy(void *dst, const void *src, u32 size)
302{
303 const long *lsrc = src;
304 long *ldst = dst;
305
306 size /= sizeof(long);
307 while (size--)
308 *ldst++ = *lsrc++;
309}
310
61e021f3 311/* verify correctness of eBPF program */
9bac3d6d 312int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
89aa0758 313#else
0fc174de
DB
314static inline struct bpf_prog *bpf_prog_get(u32 ufd)
315{
316 return ERR_PTR(-EOPNOTSUPP);
317}
318
113214be
DB
319static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
320 enum bpf_prog_type type)
321{
322 return ERR_PTR(-EOPNOTSUPP);
323}
6d67942d
DB
324static inline struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog,
325 int i)
cc2e0b3f
BB
326{
327 return ERR_PTR(-EOPNOTSUPP);
328}
113214be 329
c540594f
DB
330static inline void bpf_prog_sub(struct bpf_prog *prog, int i)
331{
332}
333
0fc174de
DB
334static inline void bpf_prog_put(struct bpf_prog *prog)
335{
336}
6d67942d
DB
337
338static inline struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog)
aa6a5f3c
AS
339{
340 return ERR_PTR(-EOPNOTSUPP);
341}
5ccb071e
DB
342
343static inline int __bpf_prog_charge(struct user_struct *user, u32 pages)
344{
345 return 0;
346}
347
348static inline void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
349{
350}
61e021f3 351#endif /* CONFIG_BPF_SYSCALL */
09756af4 352
d0003ec0 353/* verifier prototypes for helper functions called from eBPF programs */
a2c83fff
DB
354extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
355extern const struct bpf_func_proto bpf_map_update_elem_proto;
356extern const struct bpf_func_proto bpf_map_delete_elem_proto;
d0003ec0 357
03e69b50 358extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
c04167ce 359extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
2d0e30c3 360extern const struct bpf_func_proto bpf_get_numa_node_id_proto;
04fd61ab 361extern const struct bpf_func_proto bpf_tail_call_proto;
17ca8cbf 362extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
ffeedafb
AS
363extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
364extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
365extern const struct bpf_func_proto bpf_get_current_comm_proto;
4e10df9a
AS
366extern const struct bpf_func_proto bpf_skb_vlan_push_proto;
367extern const struct bpf_func_proto bpf_skb_vlan_pop_proto;
d5a3b1f6 368extern const struct bpf_func_proto bpf_get_stackid_proto;
03e69b50 369
3ad00405
DB
370/* Shared helpers among cBPF and eBPF. */
371void bpf_user_rnd_init_once(void);
372u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
373
99c55f7d 374#endif /* _LINUX_BPF_H */