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 /* Pointer types represent: 121 * pointer 122 * pointer + imm 123 * pointer + (u16) var 124 * pointer + (u16) var + imm 125 * if (range > 0) then [ptr, ptr + range - off) is safe to access 126 * if (id > 0) means that some 'var' was added 127 * if (off > 0) means that 'imm' was added 128 */ 129 enum bpf_reg_type { 130 NOT_INIT = 0, /* nothing was written into register */ 131 SCALAR_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 PTR_TO_STACK, /* reg == frame_pointer + offset */ 137 PTR_TO_PACKET, /* reg points to skb->data */ 138 PTR_TO_PACKET_END, /* skb->data + headlen */ 139 }; 140 141 struct bpf_prog; 142 143 /* The information passed from prog-specific *_is_valid_access 144 * back to the verifier. 145 */ 146 struct bpf_insn_access_aux { 147 enum bpf_reg_type reg_type; 148 int ctx_field_size; 149 }; 150 151 static inline void 152 bpf_ctx_record_field_size(struct bpf_insn_access_aux *aux, u32 size) 153 { 154 aux->ctx_field_size = size; 155 } 156 157 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); 160 161 /* return true if 'size' wide access at offset 'off' within bpf_context 162 * with 'type' (read or write) is allowed 163 */ 164 bool (*is_valid_access)(int off, int size, enum bpf_access_type type, 165 struct bpf_insn_access_aux *info); 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, u32 *target_size); 172 int (*test_run)(struct bpf_prog *prog, const union bpf_attr *kattr, 173 union bpf_attr __user *uattr); 174 }; 175 176 struct bpf_prog_aux { 177 atomic_t refcnt; 178 u32 used_map_cnt; 179 u32 max_ctx_offset; 180 u32 stack_depth; 181 u32 id; 182 struct latch_tree_node ksym_tnode; 183 struct list_head ksym_lnode; 184 const struct bpf_verifier_ops *ops; 185 struct bpf_map **used_maps; 186 struct bpf_prog *prog; 187 struct user_struct *user; 188 union { 189 struct work_struct work; 190 struct rcu_head rcu; 191 }; 192 }; 193 194 struct bpf_array { 195 struct bpf_map map; 196 u32 elem_size; 197 /* 'ownership' of prog_array is claimed by the first program that 198 * is going to use this map or by the first program which FD is stored 199 * in the map to make sure that all callers and callees have the same 200 * prog_type and JITed flag 201 */ 202 enum bpf_prog_type owner_prog_type; 203 bool owner_jited; 204 union { 205 char value[0] __aligned(8); 206 void *ptrs[0] __aligned(8); 207 void __percpu *pptrs[0] __aligned(8); 208 }; 209 }; 210 211 #define MAX_TAIL_CALL_CNT 32 212 213 struct bpf_event_entry { 214 struct perf_event *event; 215 struct file *perf_file; 216 struct file *map_file; 217 struct rcu_head rcu; 218 }; 219 220 u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5); 221 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 222 223 bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp); 224 int bpf_prog_calc_tag(struct bpf_prog *fp); 225 226 const struct bpf_func_proto *bpf_get_trace_printk_proto(void); 227 228 typedef unsigned long (*bpf_ctx_copy_t)(void *dst, const void *src, 229 unsigned long off, unsigned long len); 230 231 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 232 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy); 233 234 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr, 235 union bpf_attr __user *uattr); 236 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, 237 union bpf_attr __user *uattr); 238 239 #ifdef CONFIG_BPF_SYSCALL 240 DECLARE_PER_CPU(int, bpf_prog_active); 241 242 #define BPF_PROG_TYPE(_id, _ops) \ 243 extern const struct bpf_verifier_ops _ops; 244 #define BPF_MAP_TYPE(_id, _ops) \ 245 extern const struct bpf_map_ops _ops; 246 #include <linux/bpf_types.h> 247 #undef BPF_PROG_TYPE 248 #undef BPF_MAP_TYPE 249 250 struct bpf_prog *bpf_prog_get(u32 ufd); 251 struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type); 252 struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, int i); 253 void bpf_prog_sub(struct bpf_prog *prog, int i); 254 struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog); 255 void bpf_prog_put(struct bpf_prog *prog); 256 int __bpf_prog_charge(struct user_struct *user, u32 pages); 257 void __bpf_prog_uncharge(struct user_struct *user, u32 pages); 258 259 struct bpf_map *bpf_map_get_with_uref(u32 ufd); 260 struct bpf_map *__bpf_map_get(struct fd f); 261 struct bpf_map * __must_check bpf_map_inc(struct bpf_map *map, bool uref); 262 void bpf_map_put_with_uref(struct bpf_map *map); 263 void bpf_map_put(struct bpf_map *map); 264 int bpf_map_precharge_memlock(u32 pages); 265 void *bpf_map_area_alloc(size_t size); 266 void bpf_map_area_free(void *base); 267 268 extern int sysctl_unprivileged_bpf_disabled; 269 270 int bpf_map_new_fd(struct bpf_map *map); 271 int bpf_prog_new_fd(struct bpf_prog *prog); 272 273 int bpf_obj_pin_user(u32 ufd, const char __user *pathname); 274 int bpf_obj_get_user(const char __user *pathname); 275 276 int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value); 277 int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value); 278 int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value, 279 u64 flags); 280 int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, 281 u64 flags); 282 283 int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value); 284 285 int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, 286 void *key, void *value, u64 map_flags); 287 int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value); 288 void bpf_fd_array_map_clear(struct bpf_map *map); 289 int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file, 290 void *key, void *value, u64 map_flags); 291 int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value); 292 293 /* memcpy that is used with 8-byte aligned pointers, power-of-8 size and 294 * forced to use 'long' read/writes to try to atomically copy long counters. 295 * Best-effort only. No barriers here, since it _will_ race with concurrent 296 * updates from BPF programs. Called from bpf syscall and mostly used with 297 * size 8 or 16 bytes, so ask compiler to inline it. 298 */ 299 static inline void bpf_long_memcpy(void *dst, const void *src, u32 size) 300 { 301 const long *lsrc = src; 302 long *ldst = dst; 303 304 size /= sizeof(long); 305 while (size--) 306 *ldst++ = *lsrc++; 307 } 308 309 /* verify correctness of eBPF program */ 310 int bpf_check(struct bpf_prog **fp, union bpf_attr *attr); 311 312 /* Map specifics */ 313 struct net_device *__dev_map_lookup_elem(struct bpf_map *map, u32 key); 314 void __dev_map_insert_ctx(struct bpf_map *map, u32 index); 315 void __dev_map_flush(struct bpf_map *map); 316 317 #else 318 static inline struct bpf_prog *bpf_prog_get(u32 ufd) 319 { 320 return ERR_PTR(-EOPNOTSUPP); 321 } 322 323 static inline struct bpf_prog *bpf_prog_get_type(u32 ufd, 324 enum bpf_prog_type type) 325 { 326 return ERR_PTR(-EOPNOTSUPP); 327 } 328 static inline struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, 329 int i) 330 { 331 return ERR_PTR(-EOPNOTSUPP); 332 } 333 334 static inline void bpf_prog_sub(struct bpf_prog *prog, int i) 335 { 336 } 337 338 static inline void bpf_prog_put(struct bpf_prog *prog) 339 { 340 } 341 342 static inline struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog) 343 { 344 return ERR_PTR(-EOPNOTSUPP); 345 } 346 347 static inline int __bpf_prog_charge(struct user_struct *user, u32 pages) 348 { 349 return 0; 350 } 351 352 static inline void __bpf_prog_uncharge(struct user_struct *user, u32 pages) 353 { 354 } 355 356 static inline struct net_device *__dev_map_lookup_elem(struct bpf_map *map, 357 u32 key) 358 { 359 return NULL; 360 } 361 362 static inline void __dev_map_insert_ctx(struct bpf_map *map, u32 index) 363 { 364 } 365 366 static inline void __dev_map_flush(struct bpf_map *map) 367 { 368 } 369 #endif /* CONFIG_BPF_SYSCALL */ 370 371 /* verifier prototypes for helper functions called from eBPF programs */ 372 extern const struct bpf_func_proto bpf_map_lookup_elem_proto; 373 extern const struct bpf_func_proto bpf_map_update_elem_proto; 374 extern const struct bpf_func_proto bpf_map_delete_elem_proto; 375 376 extern const struct bpf_func_proto bpf_get_prandom_u32_proto; 377 extern const struct bpf_func_proto bpf_get_smp_processor_id_proto; 378 extern const struct bpf_func_proto bpf_get_numa_node_id_proto; 379 extern const struct bpf_func_proto bpf_tail_call_proto; 380 extern const struct bpf_func_proto bpf_ktime_get_ns_proto; 381 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto; 382 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto; 383 extern const struct bpf_func_proto bpf_get_current_comm_proto; 384 extern const struct bpf_func_proto bpf_skb_vlan_push_proto; 385 extern const struct bpf_func_proto bpf_skb_vlan_pop_proto; 386 extern const struct bpf_func_proto bpf_get_stackid_proto; 387 388 /* Shared helpers among cBPF and eBPF. */ 389 void bpf_user_rnd_init_once(void); 390 u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 391 392 #endif /* _LINUX_BPF_H */ 393