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 18 struct perf_event; 19 struct bpf_map; 20 21 /* map is generic key/value storage optionally accesible by eBPF programs */ 22 struct bpf_map_ops { 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); 28 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); 33 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, 36 int fd); 37 void (*map_fd_put_ptr)(void *ptr); 38 u32 (*map_gen_lookup)(struct bpf_map *map, struct bpf_insn *insn_buf); 39 u32 (*map_fd_sys_lookup_elem)(void *ptr); 40 }; 41 42 struct bpf_map { 43 atomic_t refcnt; 44 enum bpf_map_type map_type; 45 u32 key_size; 46 u32 value_size; 47 u32 max_entries; 48 u32 map_flags; 49 u32 pages; 50 u32 id; 51 struct user_struct *user; 52 const struct bpf_map_ops *ops; 53 struct work_struct work; 54 atomic_t usercnt; 55 struct bpf_map *inner_map_meta; 56 }; 57 58 /* function argument constraints */ 59 enum bpf_arg_type { 60 ARG_DONTCARE = 0, /* unused argument in helper function */ 61 62 /* the following constraints used to prototype 63 * bpf_map_lookup/update/delete_elem() functions 64 */ 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 */ 68 69 /* the following constraints used to prototype bpf_memcmp() and other 70 * functions that access data on eBPF program stack 71 */ 72 ARG_PTR_TO_MEM, /* pointer to valid memory (stack, packet, map value) */ 73 ARG_PTR_TO_UNINIT_MEM, /* pointer to memory does not need to be initialized, 74 * helper function must fill all bytes or clear 75 * them in error case. 76 */ 77 78 ARG_CONST_SIZE, /* number of bytes accessed from memory */ 79 ARG_CONST_SIZE_OR_ZERO, /* number of bytes accessed from memory or 0 */ 80 81 ARG_PTR_TO_CTX, /* pointer to context */ 82 ARG_ANYTHING, /* any (initialized) argument is ok */ 83 }; 84 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 */ 90 }; 91 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 95 */ 96 struct bpf_func_proto { 97 u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 98 bool gpl_only; 99 bool pkt_access; 100 enum bpf_return_type ret_type; 101 enum bpf_arg_type arg1_type; 102 enum bpf_arg_type arg2_type; 103 enum bpf_arg_type arg3_type; 104 enum bpf_arg_type arg4_type; 105 enum bpf_arg_type arg5_type; 106 }; 107 108 /* bpf_context is intentionally undefined structure. Pointer to bpf_context is 109 * the first argument to eBPF programs. 110 * For socket filters: 'struct bpf_context *' == 'struct sk_buff *' 111 */ 112 struct bpf_context; 113 114 enum bpf_access_type { 115 BPF_READ = 1, 116 BPF_WRITE = 2 117 }; 118 119 /* types of values stored in eBPF registers */ 120 enum bpf_reg_type { 121 NOT_INIT = 0, /* nothing was written into register */ 122 UNKNOWN_VALUE, /* reg doesn't contain a valid pointer */ 123 PTR_TO_CTX, /* reg points to bpf_context */ 124 CONST_PTR_TO_MAP, /* reg points to struct bpf_map */ 125 PTR_TO_MAP_VALUE, /* reg points to map element value */ 126 PTR_TO_MAP_VALUE_OR_NULL,/* points to map elem value or NULL */ 127 FRAME_PTR, /* reg == frame_pointer */ 128 PTR_TO_STACK, /* reg == frame_pointer + imm */ 129 CONST_IMM, /* constant integer value */ 130 131 /* PTR_TO_PACKET represents: 132 * skb->data 133 * skb->data + imm 134 * skb->data + (u16) var 135 * skb->data + (u16) var + imm 136 * if (range > 0) then [ptr, ptr + range - off) is safe to access 137 * if (id > 0) means that some 'var' was added 138 * if (off > 0) menas that 'imm' was added 139 */ 140 PTR_TO_PACKET, 141 PTR_TO_PACKET_END, /* skb->data + headlen */ 142 143 /* PTR_TO_MAP_VALUE_ADJ is used for doing pointer math inside of a map 144 * elem value. We only allow this if we can statically verify that 145 * access from this register are going to fall within the size of the 146 * map element. 147 */ 148 PTR_TO_MAP_VALUE_ADJ, 149 }; 150 151 struct bpf_prog; 152 153 /* The information passed from prog-specific *_is_valid_access 154 * back to the verifier. 155 */ 156 struct bpf_insn_access_aux { 157 enum bpf_reg_type reg_type; 158 int ctx_field_size; 159 }; 160 161 static inline void 162 bpf_ctx_record_field_size(struct bpf_insn_access_aux *aux, u32 size) 163 { 164 aux->ctx_field_size = size; 165 } 166 167 struct bpf_verifier_ops { 168 /* return eBPF function prototype for verification */ 169 const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id); 170 171 /* return true if 'size' wide access at offset 'off' within bpf_context 172 * with 'type' (read or write) is allowed 173 */ 174 bool (*is_valid_access)(int off, int size, enum bpf_access_type type, 175 struct bpf_insn_access_aux *info); 176 int (*gen_prologue)(struct bpf_insn *insn, bool direct_write, 177 const struct bpf_prog *prog); 178 u32 (*convert_ctx_access)(enum bpf_access_type type, 179 const struct bpf_insn *src, 180 struct bpf_insn *dst, 181 struct bpf_prog *prog, u32 *target_size); 182 int (*test_run)(struct bpf_prog *prog, const union bpf_attr *kattr, 183 union bpf_attr __user *uattr); 184 }; 185 186 struct bpf_prog_aux { 187 atomic_t refcnt; 188 u32 used_map_cnt; 189 u32 max_ctx_offset; 190 u32 stack_depth; 191 u32 id; 192 struct latch_tree_node ksym_tnode; 193 struct list_head ksym_lnode; 194 const struct bpf_verifier_ops *ops; 195 struct bpf_map **used_maps; 196 struct bpf_prog *prog; 197 struct user_struct *user; 198 union { 199 struct work_struct work; 200 struct rcu_head rcu; 201 }; 202 }; 203 204 struct bpf_array { 205 struct bpf_map map; 206 u32 elem_size; 207 /* 'ownership' of prog_array is claimed by the first program that 208 * is going to use this map or by the first program which FD is stored 209 * in the map to make sure that all callers and callees have the same 210 * prog_type and JITed flag 211 */ 212 enum bpf_prog_type owner_prog_type; 213 bool owner_jited; 214 union { 215 char value[0] __aligned(8); 216 void *ptrs[0] __aligned(8); 217 void __percpu *pptrs[0] __aligned(8); 218 }; 219 }; 220 221 #define MAX_TAIL_CALL_CNT 32 222 223 struct bpf_event_entry { 224 struct perf_event *event; 225 struct file *perf_file; 226 struct file *map_file; 227 struct rcu_head rcu; 228 }; 229 230 u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5); 231 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 232 233 bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp); 234 int bpf_prog_calc_tag(struct bpf_prog *fp); 235 236 const struct bpf_func_proto *bpf_get_trace_printk_proto(void); 237 238 typedef unsigned long (*bpf_ctx_copy_t)(void *dst, const void *src, 239 unsigned long off, unsigned long len); 240 241 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 242 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy); 243 244 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr, 245 union bpf_attr __user *uattr); 246 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, 247 union bpf_attr __user *uattr); 248 249 #ifdef CONFIG_BPF_SYSCALL 250 DECLARE_PER_CPU(int, bpf_prog_active); 251 252 #define BPF_PROG_TYPE(_id, _ops) \ 253 extern const struct bpf_verifier_ops _ops; 254 #define BPF_MAP_TYPE(_id, _ops) \ 255 extern const struct bpf_map_ops _ops; 256 #include <linux/bpf_types.h> 257 #undef BPF_PROG_TYPE 258 #undef BPF_MAP_TYPE 259 260 struct bpf_prog *bpf_prog_get(u32 ufd); 261 struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type); 262 struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, int i); 263 void bpf_prog_sub(struct bpf_prog *prog, int i); 264 struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog); 265 void bpf_prog_put(struct bpf_prog *prog); 266 int __bpf_prog_charge(struct user_struct *user, u32 pages); 267 void __bpf_prog_uncharge(struct user_struct *user, u32 pages); 268 269 struct bpf_map *bpf_map_get_with_uref(u32 ufd); 270 struct bpf_map *__bpf_map_get(struct fd f); 271 struct bpf_map * __must_check bpf_map_inc(struct bpf_map *map, bool uref); 272 void bpf_map_put_with_uref(struct bpf_map *map); 273 void bpf_map_put(struct bpf_map *map); 274 int bpf_map_precharge_memlock(u32 pages); 275 void *bpf_map_area_alloc(size_t size); 276 void bpf_map_area_free(void *base); 277 278 extern int sysctl_unprivileged_bpf_disabled; 279 280 int bpf_map_new_fd(struct bpf_map *map); 281 int bpf_prog_new_fd(struct bpf_prog *prog); 282 283 int bpf_obj_pin_user(u32 ufd, const char __user *pathname); 284 int bpf_obj_get_user(const char __user *pathname); 285 286 int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value); 287 int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value); 288 int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value, 289 u64 flags); 290 int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, 291 u64 flags); 292 293 int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value); 294 295 int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, 296 void *key, void *value, u64 map_flags); 297 int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value); 298 void bpf_fd_array_map_clear(struct bpf_map *map); 299 int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file, 300 void *key, void *value, u64 map_flags); 301 int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value); 302 303 /* memcpy that is used with 8-byte aligned pointers, power-of-8 size and 304 * forced to use 'long' read/writes to try to atomically copy long counters. 305 * Best-effort only. No barriers here, since it _will_ race with concurrent 306 * updates from BPF programs. Called from bpf syscall and mostly used with 307 * size 8 or 16 bytes, so ask compiler to inline it. 308 */ 309 static inline void bpf_long_memcpy(void *dst, const void *src, u32 size) 310 { 311 const long *lsrc = src; 312 long *ldst = dst; 313 314 size /= sizeof(long); 315 while (size--) 316 *ldst++ = *lsrc++; 317 } 318 319 /* verify correctness of eBPF program */ 320 int bpf_check(struct bpf_prog **fp, union bpf_attr *attr); 321 322 /* Map specifics */ 323 struct net_device *__dev_map_lookup_elem(struct bpf_map *map, u32 key); 324 void __dev_map_insert_ctx(struct bpf_map *map, u32 index); 325 void __dev_map_flush(struct bpf_map *map); 326 327 #else 328 static inline struct bpf_prog *bpf_prog_get(u32 ufd) 329 { 330 return ERR_PTR(-EOPNOTSUPP); 331 } 332 333 static inline struct bpf_prog *bpf_prog_get_type(u32 ufd, 334 enum bpf_prog_type type) 335 { 336 return ERR_PTR(-EOPNOTSUPP); 337 } 338 static inline struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, 339 int i) 340 { 341 return ERR_PTR(-EOPNOTSUPP); 342 } 343 344 static inline void bpf_prog_sub(struct bpf_prog *prog, int i) 345 { 346 } 347 348 static inline void bpf_prog_put(struct bpf_prog *prog) 349 { 350 } 351 352 static inline struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog) 353 { 354 return ERR_PTR(-EOPNOTSUPP); 355 } 356 357 static inline int __bpf_prog_charge(struct user_struct *user, u32 pages) 358 { 359 return 0; 360 } 361 362 static inline void __bpf_prog_uncharge(struct user_struct *user, u32 pages) 363 { 364 } 365 366 static inline struct net_device *__dev_map_lookup_elem(struct bpf_map *map, 367 u32 key) 368 { 369 return NULL; 370 } 371 372 static inline void __dev_map_insert_ctx(struct bpf_map *map, u32 index) 373 { 374 } 375 376 static inline void __dev_map_flush(struct bpf_map *map) 377 { 378 } 379 #endif /* CONFIG_BPF_SYSCALL */ 380 381 /* verifier prototypes for helper functions called from eBPF programs */ 382 extern const struct bpf_func_proto bpf_map_lookup_elem_proto; 383 extern const struct bpf_func_proto bpf_map_update_elem_proto; 384 extern const struct bpf_func_proto bpf_map_delete_elem_proto; 385 386 extern const struct bpf_func_proto bpf_get_prandom_u32_proto; 387 extern const struct bpf_func_proto bpf_get_smp_processor_id_proto; 388 extern const struct bpf_func_proto bpf_get_numa_node_id_proto; 389 extern const struct bpf_func_proto bpf_tail_call_proto; 390 extern const struct bpf_func_proto bpf_ktime_get_ns_proto; 391 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto; 392 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto; 393 extern const struct bpf_func_proto bpf_get_current_comm_proto; 394 extern const struct bpf_func_proto bpf_skb_vlan_push_proto; 395 extern const struct bpf_func_proto bpf_skb_vlan_pop_proto; 396 extern const struct bpf_func_proto bpf_get_stackid_proto; 397 398 /* Shared helpers among cBPF and eBPF. */ 399 void bpf_user_rnd_init_once(void); 400 u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 401 402 #endif /* _LINUX_BPF_H */ 403