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>
12 #include <linux/workqueue.h>
13 #include <linux/file.h>
14 #include <linux/percpu.h>
15 #include <linux/err.h>
16 #include <linux/rbtree_latch.h>
21 /* map is generic key/value storage optionally accesible by eBPF programs */
23 /* funcs callable from userspace (via syscall) */
24 struct bpf_map *(*map_alloc)(union bpf_attr *attr);
25 void (*map_release)(struct bpf_map *map, struct file *map_file);
26 void (*map_free)(struct bpf_map *map);
27 int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key);
29 /* funcs callable from userspace and from eBPF programs */
30 void *(*map_lookup_elem)(struct bpf_map *map, void *key);
31 int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags);
32 int (*map_delete_elem)(struct bpf_map *map, void *key);
34 /* funcs called by prog_array and perf_event_array map */
35 void *(*map_fd_get_ptr)(struct bpf_map *map, struct file *map_file,
37 void (*map_fd_put_ptr)(void *ptr);
38 u32 (*map_gen_lookup)(struct bpf_map *map, struct bpf_insn *insn_buf);
43 enum bpf_map_type map_type;
49 struct user_struct *user;
50 const struct bpf_map_ops *ops;
51 struct work_struct work;
53 struct bpf_map *inner_map_meta;
56 struct bpf_map_type_list {
57 struct list_head list_node;
58 const struct bpf_map_ops *ops;
59 enum bpf_map_type type;
62 /* function argument constraints */
64 ARG_DONTCARE = 0, /* unused argument in helper function */
66 /* the following constraints used to prototype
67 * bpf_map_lookup/update/delete_elem() functions
69 ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */
70 ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */
71 ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */
73 /* the following constraints used to prototype bpf_memcmp() and other
74 * functions that access data on eBPF program stack
76 ARG_PTR_TO_MEM, /* pointer to valid memory (stack, packet, map value) */
77 ARG_PTR_TO_UNINIT_MEM, /* pointer to memory does not need to be initialized,
78 * helper function must fill all bytes or clear
82 ARG_CONST_SIZE, /* number of bytes accessed from memory */
83 ARG_CONST_SIZE_OR_ZERO, /* number of bytes accessed from memory or 0 */
85 ARG_PTR_TO_CTX, /* pointer to context */
86 ARG_ANYTHING, /* any (initialized) argument is ok */
89 /* type of values returned from helper functions */
90 enum bpf_return_type {
91 RET_INTEGER, /* function returns integer */
92 RET_VOID, /* function doesn't return anything */
93 RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */
96 /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
97 * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
98 * instructions after verifying
100 struct bpf_func_proto {
101 u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
104 enum bpf_return_type ret_type;
105 enum bpf_arg_type arg1_type;
106 enum bpf_arg_type arg2_type;
107 enum bpf_arg_type arg3_type;
108 enum bpf_arg_type arg4_type;
109 enum bpf_arg_type arg5_type;
112 /* bpf_context is intentionally undefined structure. Pointer to bpf_context is
113 * the first argument to eBPF programs.
114 * For socket filters: 'struct bpf_context *' == 'struct sk_buff *'
118 enum bpf_access_type {
123 /* types of values stored in eBPF registers */
125 NOT_INIT = 0, /* nothing was written into register */
126 UNKNOWN_VALUE, /* reg doesn't contain a valid pointer */
127 PTR_TO_CTX, /* reg points to bpf_context */
128 CONST_PTR_TO_MAP, /* reg points to struct bpf_map */
129 PTR_TO_MAP_VALUE, /* reg points to map element value */
130 PTR_TO_MAP_VALUE_OR_NULL,/* points to map elem value or NULL */
131 FRAME_PTR, /* reg == frame_pointer */
132 PTR_TO_STACK, /* reg == frame_pointer + imm */
133 CONST_IMM, /* constant integer value */
135 /* PTR_TO_PACKET represents:
138 * skb->data + (u16) var
139 * skb->data + (u16) var + imm
140 * if (range > 0) then [ptr, ptr + range - off) is safe to access
141 * if (id > 0) means that some 'var' was added
142 * if (off > 0) menas that 'imm' was added
145 PTR_TO_PACKET_END, /* skb->data + headlen */
147 /* PTR_TO_MAP_VALUE_ADJ is used for doing pointer math inside of a map
148 * elem value. We only allow this if we can statically verify that
149 * access from this register are going to fall within the size of the
152 PTR_TO_MAP_VALUE_ADJ,
157 struct bpf_verifier_ops {
158 /* return eBPF function prototype for verification */
159 const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id);
161 /* return true if 'size' wide access at offset 'off' within bpf_context
162 * with 'type' (read or write) is allowed
164 bool (*is_valid_access)(int off, int size, enum bpf_access_type type,
165 enum bpf_reg_type *reg_type);
166 int (*gen_prologue)(struct bpf_insn *insn, bool direct_write,
167 const struct bpf_prog *prog);
168 u32 (*convert_ctx_access)(enum bpf_access_type type,
169 const struct bpf_insn *src,
170 struct bpf_insn *dst,
171 struct bpf_prog *prog);
172 int (*test_run)(struct bpf_prog *prog, const union bpf_attr *kattr,
173 union bpf_attr __user *uattr);
176 struct bpf_prog_aux {
180 struct latch_tree_node ksym_tnode;
181 struct list_head ksym_lnode;
182 const struct bpf_verifier_ops *ops;
183 struct bpf_map **used_maps;
184 struct bpf_prog *prog;
185 struct user_struct *user;
187 struct work_struct work;
195 /* 'ownership' of prog_array is claimed by the first program that
196 * is going to use this map or by the first program which FD is stored
197 * in the map to make sure that all callers and callees have the same
198 * prog_type and JITed flag
200 enum bpf_prog_type owner_prog_type;
203 char value[0] __aligned(8);
204 void *ptrs[0] __aligned(8);
205 void __percpu *pptrs[0] __aligned(8);
209 #define MAX_TAIL_CALL_CNT 32
211 struct bpf_event_entry {
212 struct perf_event *event;
213 struct file *perf_file;
214 struct file *map_file;
218 u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
219 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
221 bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp);
222 int bpf_prog_calc_tag(struct bpf_prog *fp);
224 const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
226 typedef unsigned long (*bpf_ctx_copy_t)(void *dst, const void *src,
227 unsigned long off, unsigned long len);
229 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
230 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy);
232 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
233 union bpf_attr __user *uattr);
234 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
235 union bpf_attr __user *uattr);
237 #ifdef CONFIG_BPF_SYSCALL
238 DECLARE_PER_CPU(int, bpf_prog_active);
240 #define BPF_PROG_TYPE(_id, _ops) \
241 extern const struct bpf_verifier_ops _ops;
242 #include <linux/bpf_types.h>
245 void bpf_register_map_type(struct bpf_map_type_list *tl);
247 struct bpf_prog *bpf_prog_get(u32 ufd);
248 struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type);
249 struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, int i);
250 void bpf_prog_sub(struct bpf_prog *prog, int i);
251 struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog);
252 void bpf_prog_put(struct bpf_prog *prog);
253 int __bpf_prog_charge(struct user_struct *user, u32 pages);
254 void __bpf_prog_uncharge(struct user_struct *user, u32 pages);
256 struct bpf_map *bpf_map_get_with_uref(u32 ufd);
257 struct bpf_map *__bpf_map_get(struct fd f);
258 struct bpf_map * __must_check bpf_map_inc(struct bpf_map *map, bool uref);
259 void bpf_map_put_with_uref(struct bpf_map *map);
260 void bpf_map_put(struct bpf_map *map);
261 int bpf_map_precharge_memlock(u32 pages);
262 void *bpf_map_area_alloc(size_t size);
263 void bpf_map_area_free(void *base);
265 extern int sysctl_unprivileged_bpf_disabled;
267 int bpf_map_new_fd(struct bpf_map *map);
268 int bpf_prog_new_fd(struct bpf_prog *prog);
270 int bpf_obj_pin_user(u32 ufd, const char __user *pathname);
271 int bpf_obj_get_user(const char __user *pathname);
273 int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value);
274 int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value);
275 int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
277 int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
280 int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value);
282 int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
283 void *key, void *value, u64 map_flags);
284 void bpf_fd_array_map_clear(struct bpf_map *map);
285 int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file,
286 void *key, void *value, u64 map_flags);
288 /* memcpy that is used with 8-byte aligned pointers, power-of-8 size and
289 * forced to use 'long' read/writes to try to atomically copy long counters.
290 * Best-effort only. No barriers here, since it _will_ race with concurrent
291 * updates from BPF programs. Called from bpf syscall and mostly used with
292 * size 8 or 16 bytes, so ask compiler to inline it.
294 static inline void bpf_long_memcpy(void *dst, const void *src, u32 size)
296 const long *lsrc = src;
299 size /= sizeof(long);
304 /* verify correctness of eBPF program */
305 int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
307 static inline struct bpf_prog *bpf_prog_get(u32 ufd)
309 return ERR_PTR(-EOPNOTSUPP);
312 static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
313 enum bpf_prog_type type)
315 return ERR_PTR(-EOPNOTSUPP);
317 static inline struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog,
320 return ERR_PTR(-EOPNOTSUPP);
323 static inline void bpf_prog_sub(struct bpf_prog *prog, int i)
327 static inline void bpf_prog_put(struct bpf_prog *prog)
331 static inline struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog)
333 return ERR_PTR(-EOPNOTSUPP);
336 static inline int __bpf_prog_charge(struct user_struct *user, u32 pages)
341 static inline void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
344 #endif /* CONFIG_BPF_SYSCALL */
346 /* verifier prototypes for helper functions called from eBPF programs */
347 extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
348 extern const struct bpf_func_proto bpf_map_update_elem_proto;
349 extern const struct bpf_func_proto bpf_map_delete_elem_proto;
351 extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
352 extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
353 extern const struct bpf_func_proto bpf_get_numa_node_id_proto;
354 extern const struct bpf_func_proto bpf_tail_call_proto;
355 extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
356 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
357 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
358 extern const struct bpf_func_proto bpf_get_current_comm_proto;
359 extern const struct bpf_func_proto bpf_skb_vlan_push_proto;
360 extern const struct bpf_func_proto bpf_skb_vlan_pop_proto;
361 extern const struct bpf_func_proto bpf_get_stackid_proto;
363 /* Shared helpers among cBPF and eBPF. */
364 void bpf_user_rnd_init_once(void);
365 u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
367 #endif /* _LINUX_BPF_H */