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> 11 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> 17 #include <linux/numa.h> 18 19 struct perf_event; 20 struct bpf_prog; 21 struct bpf_map; 22 23 /* map is generic key/value storage optionally accesible by eBPF programs */ 24 struct bpf_map_ops { 25 /* funcs callable from userspace (via syscall) */ 26 struct bpf_map *(*map_alloc)(union bpf_attr *attr); 27 void (*map_release)(struct bpf_map *map, struct file *map_file); 28 void (*map_free)(struct bpf_map *map); 29 int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key); 30 31 /* funcs callable from userspace and from eBPF programs */ 32 void *(*map_lookup_elem)(struct bpf_map *map, void *key); 33 int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags); 34 int (*map_delete_elem)(struct bpf_map *map, void *key); 35 36 /* funcs called by prog_array and perf_event_array map */ 37 void *(*map_fd_get_ptr)(struct bpf_map *map, struct file *map_file, 38 int fd); 39 void (*map_fd_put_ptr)(void *ptr); 40 u32 (*map_gen_lookup)(struct bpf_map *map, struct bpf_insn *insn_buf); 41 u32 (*map_fd_sys_lookup_elem)(void *ptr); 42 }; 43 44 struct bpf_map { 45 atomic_t refcnt; 46 enum bpf_map_type map_type; 47 u32 key_size; 48 u32 value_size; 49 u32 max_entries; 50 u32 map_flags; 51 u32 pages; 52 u32 id; 53 int numa_node; 54 struct user_struct *user; 55 const struct bpf_map_ops *ops; 56 struct work_struct work; 57 atomic_t usercnt; 58 struct bpf_map *inner_map_meta; 59 }; 60 61 /* function argument constraints */ 62 enum bpf_arg_type { 63 ARG_DONTCARE = 0, /* unused argument in helper function */ 64 65 /* the following constraints used to prototype 66 * bpf_map_lookup/update/delete_elem() functions 67 */ 68 ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */ 69 ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */ 70 ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */ 71 72 /* the following constraints used to prototype bpf_memcmp() and other 73 * functions that access data on eBPF program stack 74 */ 75 ARG_PTR_TO_MEM, /* pointer to valid memory (stack, packet, map value) */ 76 ARG_PTR_TO_UNINIT_MEM, /* pointer to memory does not need to be initialized, 77 * helper function must fill all bytes or clear 78 * them in error case. 79 */ 80 81 ARG_CONST_SIZE, /* number of bytes accessed from memory */ 82 ARG_CONST_SIZE_OR_ZERO, /* number of bytes accessed from memory or 0 */ 83 84 ARG_PTR_TO_CTX, /* pointer to context */ 85 ARG_ANYTHING, /* any (initialized) argument is ok */ 86 }; 87 88 /* type of values returned from helper functions */ 89 enum bpf_return_type { 90 RET_INTEGER, /* function returns integer */ 91 RET_VOID, /* function doesn't return anything */ 92 RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */ 93 }; 94 95 /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs 96 * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL 97 * instructions after verifying 98 */ 99 struct bpf_func_proto { 100 u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 101 bool gpl_only; 102 bool pkt_access; 103 enum bpf_return_type ret_type; 104 enum bpf_arg_type arg1_type; 105 enum bpf_arg_type arg2_type; 106 enum bpf_arg_type arg3_type; 107 enum bpf_arg_type arg4_type; 108 enum bpf_arg_type arg5_type; 109 }; 110 111 /* bpf_context is intentionally undefined structure. Pointer to bpf_context is 112 * the first argument to eBPF programs. 113 * For socket filters: 'struct bpf_context *' == 'struct sk_buff *' 114 */ 115 struct bpf_context; 116 117 enum bpf_access_type { 118 BPF_READ = 1, 119 BPF_WRITE = 2 120 }; 121 122 /* types of values stored in eBPF registers */ 123 /* Pointer types represent: 124 * pointer 125 * pointer + imm 126 * pointer + (u16) var 127 * pointer + (u16) var + imm 128 * if (range > 0) then [ptr, ptr + range - off) is safe to access 129 * if (id > 0) means that some 'var' was added 130 * if (off > 0) means that 'imm' was added 131 */ 132 enum bpf_reg_type { 133 NOT_INIT = 0, /* nothing was written into register */ 134 SCALAR_VALUE, /* reg doesn't contain a valid pointer */ 135 PTR_TO_CTX, /* reg points to bpf_context */ 136 CONST_PTR_TO_MAP, /* reg points to struct bpf_map */ 137 PTR_TO_MAP_VALUE, /* reg points to map element value */ 138 PTR_TO_MAP_VALUE_OR_NULL,/* points to map elem value or NULL */ 139 PTR_TO_STACK, /* reg == frame_pointer + offset */ 140 PTR_TO_PACKET, /* reg points to skb->data */ 141 PTR_TO_PACKET_END, /* skb->data + headlen */ 142 }; 143 144 /* The information passed from prog-specific *_is_valid_access 145 * back to the verifier. 146 */ 147 struct bpf_insn_access_aux { 148 enum bpf_reg_type reg_type; 149 int ctx_field_size; 150 }; 151 152 static inline void 153 bpf_ctx_record_field_size(struct bpf_insn_access_aux *aux, u32 size) 154 { 155 aux->ctx_field_size = size; 156 } 157 158 struct bpf_verifier_ops { 159 /* return eBPF function prototype for verification */ 160 const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id); 161 162 /* return true if 'size' wide access at offset 'off' within bpf_context 163 * with 'type' (read or write) is allowed 164 */ 165 bool (*is_valid_access)(int off, int size, enum bpf_access_type type, 166 struct bpf_insn_access_aux *info); 167 int (*gen_prologue)(struct bpf_insn *insn, bool direct_write, 168 const struct bpf_prog *prog); 169 u32 (*convert_ctx_access)(enum bpf_access_type type, 170 const struct bpf_insn *src, 171 struct bpf_insn *dst, 172 struct bpf_prog *prog, u32 *target_size); 173 int (*test_run)(struct bpf_prog *prog, const union bpf_attr *kattr, 174 union bpf_attr __user *uattr); 175 }; 176 177 struct bpf_prog_aux { 178 atomic_t refcnt; 179 u32 used_map_cnt; 180 u32 max_ctx_offset; 181 u32 stack_depth; 182 u32 id; 183 struct latch_tree_node ksym_tnode; 184 struct list_head ksym_lnode; 185 const struct bpf_verifier_ops *ops; 186 struct bpf_map **used_maps; 187 struct bpf_prog *prog; 188 struct user_struct *user; 189 union { 190 struct work_struct work; 191 struct rcu_head rcu; 192 }; 193 }; 194 195 struct bpf_array { 196 struct bpf_map map; 197 u32 elem_size; 198 /* 'ownership' of prog_array is claimed by the first program that 199 * is going to use this map or by the first program which FD is stored 200 * in the map to make sure that all callers and callees have the same 201 * prog_type and JITed flag 202 */ 203 enum bpf_prog_type owner_prog_type; 204 bool owner_jited; 205 union { 206 char value[0] __aligned(8); 207 void *ptrs[0] __aligned(8); 208 void __percpu *pptrs[0] __aligned(8); 209 }; 210 }; 211 212 #define MAX_TAIL_CALL_CNT 32 213 214 struct bpf_event_entry { 215 struct perf_event *event; 216 struct file *perf_file; 217 struct file *map_file; 218 struct rcu_head rcu; 219 }; 220 221 u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5); 222 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 223 224 bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp); 225 int bpf_prog_calc_tag(struct bpf_prog *fp); 226 227 const struct bpf_func_proto *bpf_get_trace_printk_proto(void); 228 229 typedef unsigned long (*bpf_ctx_copy_t)(void *dst, const void *src, 230 unsigned long off, unsigned long len); 231 232 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 233 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy); 234 235 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr, 236 union bpf_attr __user *uattr); 237 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, 238 union bpf_attr __user *uattr); 239 240 #ifdef CONFIG_BPF_SYSCALL 241 DECLARE_PER_CPU(int, bpf_prog_active); 242 243 #define BPF_PROG_TYPE(_id, _ops) \ 244 extern const struct bpf_verifier_ops _ops; 245 #define BPF_MAP_TYPE(_id, _ops) \ 246 extern const struct bpf_map_ops _ops; 247 #include <linux/bpf_types.h> 248 #undef BPF_PROG_TYPE 249 #undef BPF_MAP_TYPE 250 251 struct bpf_prog *bpf_prog_get(u32 ufd); 252 struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type); 253 struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, int i); 254 void bpf_prog_sub(struct bpf_prog *prog, int i); 255 struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog); 256 struct bpf_prog * __must_check bpf_prog_inc_not_zero(struct bpf_prog *prog); 257 void bpf_prog_put(struct bpf_prog *prog); 258 int __bpf_prog_charge(struct user_struct *user, u32 pages); 259 void __bpf_prog_uncharge(struct user_struct *user, u32 pages); 260 261 struct bpf_map *bpf_map_get_with_uref(u32 ufd); 262 struct bpf_map *__bpf_map_get(struct fd f); 263 struct bpf_map * __must_check bpf_map_inc(struct bpf_map *map, bool uref); 264 void bpf_map_put_with_uref(struct bpf_map *map); 265 void bpf_map_put(struct bpf_map *map); 266 int bpf_map_precharge_memlock(u32 pages); 267 void *bpf_map_area_alloc(size_t size, int numa_node); 268 void bpf_map_area_free(void *base); 269 270 extern int sysctl_unprivileged_bpf_disabled; 271 272 int bpf_map_new_fd(struct bpf_map *map); 273 int bpf_prog_new_fd(struct bpf_prog *prog); 274 275 int bpf_obj_pin_user(u32 ufd, const char __user *pathname); 276 int bpf_obj_get_user(const char __user *pathname); 277 278 int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value); 279 int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value); 280 int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value, 281 u64 flags); 282 int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, 283 u64 flags); 284 285 int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value); 286 287 int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, 288 void *key, void *value, u64 map_flags); 289 int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value); 290 void bpf_fd_array_map_clear(struct bpf_map *map); 291 int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file, 292 void *key, void *value, u64 map_flags); 293 int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value); 294 295 /* 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 */ 301 static 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 } 310 311 /* verify correctness of eBPF program */ 312 int bpf_check(struct bpf_prog **fp, union bpf_attr *attr); 313 314 /* Map specifics */ 315 struct net_device *__dev_map_lookup_elem(struct bpf_map *map, u32 key); 316 void __dev_map_insert_ctx(struct bpf_map *map, u32 index); 317 void __dev_map_flush(struct bpf_map *map); 318 319 /* Return map's numa specified by userspace */ 320 static inline int bpf_map_attr_numa_node(const union bpf_attr *attr) 321 { 322 return (attr->map_flags & BPF_F_NUMA_NODE) ? 323 attr->numa_node : NUMA_NO_NODE; 324 } 325 326 #else 327 static inline struct bpf_prog *bpf_prog_get(u32 ufd) 328 { 329 return ERR_PTR(-EOPNOTSUPP); 330 } 331 332 static inline struct bpf_prog *bpf_prog_get_type(u32 ufd, 333 enum bpf_prog_type type) 334 { 335 return ERR_PTR(-EOPNOTSUPP); 336 } 337 static inline struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, 338 int i) 339 { 340 return ERR_PTR(-EOPNOTSUPP); 341 } 342 343 static inline void bpf_prog_sub(struct bpf_prog *prog, int i) 344 { 345 } 346 347 static inline void bpf_prog_put(struct bpf_prog *prog) 348 { 349 } 350 351 static inline struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog) 352 { 353 return ERR_PTR(-EOPNOTSUPP); 354 } 355 356 static inline struct bpf_prog *__must_check 357 bpf_prog_inc_not_zero(struct bpf_prog *prog) 358 { 359 return ERR_PTR(-EOPNOTSUPP); 360 } 361 362 static inline int __bpf_prog_charge(struct user_struct *user, u32 pages) 363 { 364 return 0; 365 } 366 367 static inline void __bpf_prog_uncharge(struct user_struct *user, u32 pages) 368 { 369 } 370 371 static inline int bpf_obj_get_user(const char __user *pathname) 372 { 373 return -EOPNOTSUPP; 374 } 375 376 static inline struct net_device *__dev_map_lookup_elem(struct bpf_map *map, 377 u32 key) 378 { 379 return NULL; 380 } 381 382 static inline void __dev_map_insert_ctx(struct bpf_map *map, u32 index) 383 { 384 } 385 386 static inline void __dev_map_flush(struct bpf_map *map) 387 { 388 } 389 #endif /* CONFIG_BPF_SYSCALL */ 390 391 #if defined(CONFIG_STREAM_PARSER) && defined(CONFIG_BPF_SYSCALL) 392 struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key); 393 int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type); 394 #else 395 static inline struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key) 396 { 397 return NULL; 398 } 399 400 static inline int sock_map_prog(struct bpf_map *map, 401 struct bpf_prog *prog, 402 u32 type) 403 { 404 return -EOPNOTSUPP; 405 } 406 #endif 407 408 /* verifier prototypes for helper functions called from eBPF programs */ 409 extern const struct bpf_func_proto bpf_map_lookup_elem_proto; 410 extern const struct bpf_func_proto bpf_map_update_elem_proto; 411 extern const struct bpf_func_proto bpf_map_delete_elem_proto; 412 413 extern const struct bpf_func_proto bpf_get_prandom_u32_proto; 414 extern const struct bpf_func_proto bpf_get_smp_processor_id_proto; 415 extern const struct bpf_func_proto bpf_get_numa_node_id_proto; 416 extern const struct bpf_func_proto bpf_tail_call_proto; 417 extern const struct bpf_func_proto bpf_ktime_get_ns_proto; 418 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto; 419 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto; 420 extern const struct bpf_func_proto bpf_get_current_comm_proto; 421 extern const struct bpf_func_proto bpf_skb_vlan_push_proto; 422 extern const struct bpf_func_proto bpf_skb_vlan_pop_proto; 423 extern const struct bpf_func_proto bpf_get_stackid_proto; 424 extern const struct bpf_func_proto bpf_sock_map_update_proto; 425 426 /* Shared helpers among cBPF and eBPF. */ 427 void bpf_user_rnd_init_once(void); 428 u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 429 430 #endif /* _LINUX_BPF_H */ 431