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>
14 #include <linux/err.h>
19 /* map is generic key/value storage optionally accesible by eBPF programs */
21 /* funcs callable from userspace (via syscall) */
22 struct bpf_map *(*map_alloc)(union bpf_attr *attr);
23 void (*map_release)(struct bpf_map *map, struct file *map_file);
24 void (*map_free)(struct bpf_map *map);
25 int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key);
27 /* funcs callable from userspace and from eBPF programs */
28 void *(*map_lookup_elem)(struct bpf_map *map, void *key);
29 int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags);
30 int (*map_delete_elem)(struct bpf_map *map, void *key);
32 /* funcs called by prog_array and perf_event_array map */
33 void *(*map_fd_get_ptr)(struct bpf_map *map, struct file *map_file,
35 void (*map_fd_put_ptr)(void *ptr);
39 /* 1st cacheline with read-mostly members of which some
40 * are also accessed in fast-path (e.g. ops, max_entries).
42 const struct bpf_map_ops *ops ____cacheline_aligned;
43 enum bpf_map_type map_type;
52 /* 2nd cacheline with misc members to avoid false sharing
53 * particularly with refcounting.
55 struct user_struct *user ____cacheline_aligned;
58 struct work_struct work;
61 struct bpf_map_type_list {
62 struct list_head list_node;
63 const struct bpf_map_ops *ops;
64 enum bpf_map_type type;
67 /* function argument constraints */
69 ARG_DONTCARE = 0, /* unused argument in helper function */
71 /* the following constraints used to prototype
72 * bpf_map_lookup/update/delete_elem() functions
74 ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */
75 ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */
76 ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */
78 /* the following constraints used to prototype bpf_memcmp() and other
79 * functions that access data on eBPF program stack
81 ARG_PTR_TO_STACK, /* any pointer to eBPF program stack */
82 ARG_PTR_TO_RAW_STACK, /* any pointer to eBPF program stack, area does not
83 * need to be initialized, helper function must fill
84 * all bytes or clear them in error case.
87 ARG_CONST_STACK_SIZE, /* number of bytes accessed from stack */
88 ARG_CONST_STACK_SIZE_OR_ZERO, /* number of bytes accessed from stack or 0 */
90 ARG_PTR_TO_CTX, /* pointer to context */
91 ARG_ANYTHING, /* any (initialized) argument is ok */
94 /* type of values returned from helper functions */
95 enum bpf_return_type {
96 RET_INTEGER, /* function returns integer */
97 RET_VOID, /* function doesn't return anything */
98 RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */
101 /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
102 * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
103 * instructions after verifying
105 struct bpf_func_proto {
106 u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
109 enum bpf_return_type ret_type;
110 enum bpf_arg_type arg1_type;
111 enum bpf_arg_type arg2_type;
112 enum bpf_arg_type arg3_type;
113 enum bpf_arg_type arg4_type;
114 enum bpf_arg_type arg5_type;
117 /* bpf_context is intentionally undefined structure. Pointer to bpf_context is
118 * the first argument to eBPF programs.
119 * For socket filters: 'struct bpf_context *' == 'struct sk_buff *'
123 enum bpf_access_type {
128 /* types of values stored in eBPF registers */
130 NOT_INIT = 0, /* nothing was written into register */
131 UNKNOWN_VALUE, /* reg doesn't contain a valid pointer */
132 PTR_TO_CTX, /* reg points to bpf_context */
133 CONST_PTR_TO_MAP, /* reg points to struct bpf_map */
134 PTR_TO_MAP_VALUE, /* reg points to map element value */
135 PTR_TO_MAP_VALUE_OR_NULL,/* points to map elem value or NULL */
136 FRAME_PTR, /* reg == frame_pointer */
137 PTR_TO_STACK, /* reg == frame_pointer + imm */
138 CONST_IMM, /* constant integer value */
140 /* PTR_TO_PACKET represents:
143 * skb->data + (u16) var
144 * skb->data + (u16) var + imm
145 * if (range > 0) then [ptr, ptr + range - off) is safe to access
146 * if (id > 0) means that some 'var' was added
147 * if (off > 0) menas that 'imm' was added
150 PTR_TO_PACKET_END, /* skb->data + headlen */
152 /* PTR_TO_MAP_VALUE_ADJ is used for doing pointer math inside of a map
153 * elem value. We only allow this if we can statically verify that
154 * access from this register are going to fall within the size of the
157 PTR_TO_MAP_VALUE_ADJ,
162 struct bpf_verifier_ops {
163 /* return eBPF function prototype for verification */
164 const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id);
166 /* return true if 'size' wide access at offset 'off' within bpf_context
167 * with 'type' (read or write) is allowed
169 bool (*is_valid_access)(int off, int size, enum bpf_access_type type,
170 enum bpf_reg_type *reg_type);
171 int (*gen_prologue)(struct bpf_insn *insn, bool direct_write,
172 const struct bpf_prog *prog);
173 u32 (*convert_ctx_access)(enum bpf_access_type type, int dst_reg,
174 int src_reg, int ctx_off,
175 struct bpf_insn *insn, struct bpf_prog *prog);
178 struct bpf_prog_type_list {
179 struct list_head list_node;
180 const struct bpf_verifier_ops *ops;
181 enum bpf_prog_type type;
184 struct bpf_prog_aux {
188 const struct bpf_verifier_ops *ops;
189 struct bpf_map **used_maps;
190 struct bpf_prog *prog;
191 struct user_struct *user;
193 struct work_struct work;
202 /* 'ownership' of prog_array is claimed by the first program that
203 * is going to use this map or by the first program which FD is stored
204 * in the map to make sure that all callers and callees have the same
205 * prog_type and JITed flag
207 enum bpf_prog_type owner_prog_type;
210 char value[0] __aligned(8);
211 void *ptrs[0] __aligned(8);
212 void __percpu *pptrs[0] __aligned(8);
216 #define MAX_TAIL_CALL_CNT 32
218 struct bpf_event_entry {
219 struct perf_event *event;
220 struct file *perf_file;
221 struct file *map_file;
225 u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
226 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
228 bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp);
230 const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
232 typedef unsigned long (*bpf_ctx_copy_t)(void *dst, const void *src,
233 unsigned long off, unsigned long len);
235 u64 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);
238 #ifdef CONFIG_BPF_SYSCALL
239 DECLARE_PER_CPU(int, bpf_prog_active);
241 void bpf_register_prog_type(struct bpf_prog_type_list *tl);
242 void bpf_register_map_type(struct bpf_map_type_list *tl);
244 struct bpf_prog *bpf_prog_get(u32 ufd);
245 struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type);
246 struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i);
247 struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog);
248 void bpf_prog_put(struct bpf_prog *prog);
250 struct bpf_map *bpf_map_get_with_uref(u32 ufd);
251 struct bpf_map *__bpf_map_get(struct fd f);
252 struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref);
253 void bpf_map_put_with_uref(struct bpf_map *map);
254 void bpf_map_put(struct bpf_map *map);
255 int bpf_map_precharge_memlock(u32 pages);
256 void *bpf_map_area_alloc(size_t size);
257 void bpf_map_area_free(void *base);
259 extern int sysctl_unprivileged_bpf_disabled;
261 int bpf_map_new_fd(struct bpf_map *map);
262 int bpf_prog_new_fd(struct bpf_prog *prog);
264 int bpf_obj_pin_user(u32 ufd, const char __user *pathname);
265 int bpf_obj_get_user(const char __user *pathname);
267 int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value);
268 int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value);
269 int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
271 int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
274 int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value);
276 int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
277 void *key, void *value, u64 map_flags);
278 void bpf_fd_array_map_clear(struct bpf_map *map);
280 /* memcpy that is used with 8-byte aligned pointers, power-of-8 size and
281 * forced to use 'long' read/writes to try to atomically copy long counters.
282 * Best-effort only. No barriers here, since it _will_ race with concurrent
283 * updates from BPF programs. Called from bpf syscall and mostly used with
284 * size 8 or 16 bytes, so ask compiler to inline it.
286 static inline void bpf_long_memcpy(void *dst, const void *src, u32 size)
288 const long *lsrc = src;
291 size /= sizeof(long);
296 /* verify correctness of eBPF program */
297 int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
299 static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl)
303 static inline struct bpf_prog *bpf_prog_get(u32 ufd)
305 return ERR_PTR(-EOPNOTSUPP);
308 static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
309 enum bpf_prog_type type)
311 return ERR_PTR(-EOPNOTSUPP);
313 static inline struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
315 return ERR_PTR(-EOPNOTSUPP);
318 static inline void bpf_prog_put(struct bpf_prog *prog)
321 static inline struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
323 return ERR_PTR(-EOPNOTSUPP);
325 #endif /* CONFIG_BPF_SYSCALL */
327 /* verifier prototypes for helper functions called from eBPF programs */
328 extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
329 extern const struct bpf_func_proto bpf_map_update_elem_proto;
330 extern const struct bpf_func_proto bpf_map_delete_elem_proto;
332 extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
333 extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
334 extern const struct bpf_func_proto bpf_tail_call_proto;
335 extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
336 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
337 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
338 extern const struct bpf_func_proto bpf_get_current_comm_proto;
339 extern const struct bpf_func_proto bpf_skb_vlan_push_proto;
340 extern const struct bpf_func_proto bpf_skb_vlan_pop_proto;
341 extern const struct bpf_func_proto bpf_get_stackid_proto;
343 /* Shared helpers among cBPF and eBPF. */
344 void bpf_user_rnd_init_once(void);
345 u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
347 #endif /* _LINUX_BPF_H */