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);
40 enum bpf_map_type map_type;
46 struct user_struct *user;
47 const struct bpf_map_ops *ops;
48 struct work_struct work;
52 struct bpf_map_type_list {
53 struct list_head list_node;
54 const struct bpf_map_ops *ops;
55 enum bpf_map_type type;
58 /* function argument constraints */
60 ARG_DONTCARE = 0, /* unused argument in helper function */
62 /* the following constraints used to prototype
63 * bpf_map_lookup/update/delete_elem() functions
65 ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */
66 ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */
67 ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */
69 /* the following constraints used to prototype bpf_memcmp() and other
70 * functions that access data on eBPF program stack
72 ARG_PTR_TO_STACK, /* any pointer to eBPF program stack */
73 ARG_PTR_TO_RAW_STACK, /* any pointer to eBPF program stack, area does not
74 * need to be initialized, helper function must fill
75 * all bytes or clear them in error case.
78 ARG_CONST_STACK_SIZE, /* number of bytes accessed from stack */
79 ARG_CONST_STACK_SIZE_OR_ZERO, /* number of bytes accessed from stack or 0 */
81 ARG_PTR_TO_CTX, /* pointer to context */
82 ARG_ANYTHING, /* any (initialized) argument is ok */
85 /* type of values returned from helper functions */
86 enum bpf_return_type {
87 RET_INTEGER, /* function returns integer */
88 RET_VOID, /* function doesn't return anything */
89 RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */
92 /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
93 * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
94 * instructions after verifying
96 struct bpf_func_proto {
97 u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
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;
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 *'
113 enum bpf_access_type {
120 struct bpf_verifier_ops {
121 /* return eBPF function prototype for verification */
122 const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id);
124 /* return true if 'size' wide access at offset 'off' within bpf_context
125 * with 'type' (read or write) is allowed
127 bool (*is_valid_access)(int off, int size, enum bpf_access_type type);
129 u32 (*convert_ctx_access)(enum bpf_access_type type, int dst_reg,
130 int src_reg, int ctx_off,
131 struct bpf_insn *insn, struct bpf_prog *prog);
134 struct bpf_prog_type_list {
135 struct list_head list_node;
136 const struct bpf_verifier_ops *ops;
137 enum bpf_prog_type type;
140 struct bpf_prog_aux {
144 const struct bpf_verifier_ops *ops;
145 struct bpf_map **used_maps;
146 struct bpf_prog *prog;
147 struct user_struct *user;
149 struct work_struct work;
157 /* 'ownership' of prog_array is claimed by the first program that
158 * is going to use this map or by the first program which FD is stored
159 * in the map to make sure that all callers and callees have the same
160 * prog_type and JITed flag
162 enum bpf_prog_type owner_prog_type;
165 char value[0] __aligned(8);
166 void *ptrs[0] __aligned(8);
167 void __percpu *pptrs[0] __aligned(8);
171 #define MAX_TAIL_CALL_CNT 32
173 struct bpf_event_entry {
174 struct perf_event *event;
175 struct file *perf_file;
176 struct file *map_file;
180 u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
181 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
183 bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp);
185 const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
186 const struct bpf_func_proto *bpf_get_event_output_proto(void);
188 #ifdef CONFIG_BPF_SYSCALL
189 DECLARE_PER_CPU(int, bpf_prog_active);
191 void bpf_register_prog_type(struct bpf_prog_type_list *tl);
192 void bpf_register_map_type(struct bpf_map_type_list *tl);
194 struct bpf_prog *bpf_prog_get(u32 ufd);
195 struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog);
196 void bpf_prog_put(struct bpf_prog *prog);
197 void bpf_prog_put_rcu(struct bpf_prog *prog);
199 struct bpf_map *bpf_map_get_with_uref(u32 ufd);
200 struct bpf_map *__bpf_map_get(struct fd f);
201 struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref);
202 void bpf_map_put_with_uref(struct bpf_map *map);
203 void bpf_map_put(struct bpf_map *map);
204 int bpf_map_precharge_memlock(u32 pages);
206 extern int sysctl_unprivileged_bpf_disabled;
208 int bpf_map_new_fd(struct bpf_map *map);
209 int bpf_prog_new_fd(struct bpf_prog *prog);
211 int bpf_obj_pin_user(u32 ufd, const char __user *pathname);
212 int bpf_obj_get_user(const char __user *pathname);
214 int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value);
215 int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value);
216 int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
218 int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
221 int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value);
223 int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
224 void *key, void *value, u64 map_flags);
225 void bpf_fd_array_map_clear(struct bpf_map *map);
227 /* memcpy that is used with 8-byte aligned pointers, power-of-8 size and
228 * forced to use 'long' read/writes to try to atomically copy long counters.
229 * Best-effort only. No barriers here, since it _will_ race with concurrent
230 * updates from BPF programs. Called from bpf syscall and mostly used with
231 * size 8 or 16 bytes, so ask compiler to inline it.
233 static inline void bpf_long_memcpy(void *dst, const void *src, u32 size)
235 const long *lsrc = src;
238 size /= sizeof(long);
243 /* verify correctness of eBPF program */
244 int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
246 static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl)
250 static inline struct bpf_prog *bpf_prog_get(u32 ufd)
252 return ERR_PTR(-EOPNOTSUPP);
255 static inline void bpf_prog_put(struct bpf_prog *prog)
258 #endif /* CONFIG_BPF_SYSCALL */
260 /* verifier prototypes for helper functions called from eBPF programs */
261 extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
262 extern const struct bpf_func_proto bpf_map_update_elem_proto;
263 extern const struct bpf_func_proto bpf_map_delete_elem_proto;
265 extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
266 extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
267 extern const struct bpf_func_proto bpf_tail_call_proto;
268 extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
269 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
270 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
271 extern const struct bpf_func_proto bpf_get_current_comm_proto;
272 extern const struct bpf_func_proto bpf_skb_vlan_push_proto;
273 extern const struct bpf_func_proto bpf_skb_vlan_pop_proto;
274 extern const struct bpf_func_proto bpf_get_stackid_proto;
276 /* Shared helpers among cBPF and eBPF. */
277 void bpf_user_rnd_init_once(void);
278 u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
280 #endif /* _LINUX_BPF_H */