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 }; 39 40 struct bpf_map { 41 atomic_t refcnt; 42 enum bpf_map_type map_type; 43 u32 key_size; 44 u32 value_size; 45 u32 max_entries; 46 u32 map_flags; 47 u32 pages; 48 struct user_struct *user; 49 const struct bpf_map_ops *ops; 50 struct work_struct work; 51 atomic_t usercnt; 52 }; 53 54 struct bpf_map_type_list { 55 struct list_head list_node; 56 const struct bpf_map_ops *ops; 57 enum bpf_map_type type; 58 }; 59 60 /* function argument constraints */ 61 enum bpf_arg_type { 62 ARG_DONTCARE = 0, /* unused argument in helper function */ 63 64 /* the following constraints used to prototype 65 * bpf_map_lookup/update/delete_elem() functions 66 */ 67 ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */ 68 ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */ 69 ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */ 70 71 /* the following constraints used to prototype bpf_memcmp() and other 72 * functions that access data on eBPF program stack 73 */ 74 ARG_PTR_TO_MEM, /* pointer to valid memory (stack, packet, map value) */ 75 ARG_PTR_TO_UNINIT_MEM, /* pointer to memory does not need to be initialized, 76 * helper function must fill all bytes or clear 77 * them in error case. 78 */ 79 80 ARG_CONST_SIZE, /* number of bytes accessed from memory */ 81 ARG_CONST_SIZE_OR_ZERO, /* number of bytes accessed from memory or 0 */ 82 83 ARG_PTR_TO_CTX, /* pointer to context */ 84 ARG_ANYTHING, /* any (initialized) argument is ok */ 85 }; 86 87 /* type of values returned from helper functions */ 88 enum bpf_return_type { 89 RET_INTEGER, /* function returns integer */ 90 RET_VOID, /* function doesn't return anything */ 91 RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */ 92 }; 93 94 /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs 95 * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL 96 * instructions after verifying 97 */ 98 struct bpf_func_proto { 99 u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 100 bool gpl_only; 101 bool pkt_access; 102 enum bpf_return_type ret_type; 103 enum bpf_arg_type arg1_type; 104 enum bpf_arg_type arg2_type; 105 enum bpf_arg_type arg3_type; 106 enum bpf_arg_type arg4_type; 107 enum bpf_arg_type arg5_type; 108 }; 109 110 /* bpf_context is intentionally undefined structure. Pointer to bpf_context is 111 * the first argument to eBPF programs. 112 * For socket filters: 'struct bpf_context *' == 'struct sk_buff *' 113 */ 114 struct bpf_context; 115 116 enum bpf_access_type { 117 BPF_READ = 1, 118 BPF_WRITE = 2 119 }; 120 121 /* types of values stored in eBPF registers */ 122 enum bpf_reg_type { 123 NOT_INIT = 0, /* nothing was written into register */ 124 UNKNOWN_VALUE, /* reg doesn't contain a valid pointer */ 125 PTR_TO_CTX, /* reg points to bpf_context */ 126 CONST_PTR_TO_MAP, /* reg points to struct bpf_map */ 127 PTR_TO_MAP_VALUE, /* reg points to map element value */ 128 PTR_TO_MAP_VALUE_OR_NULL,/* points to map elem value or NULL */ 129 FRAME_PTR, /* reg == frame_pointer */ 130 PTR_TO_STACK, /* reg == frame_pointer + imm */ 131 CONST_IMM, /* constant integer value */ 132 133 /* PTR_TO_PACKET represents: 134 * skb->data 135 * skb->data + imm 136 * skb->data + (u16) var 137 * skb->data + (u16) var + imm 138 * if (range > 0) then [ptr, ptr + range - off) is safe to access 139 * if (id > 0) means that some 'var' was added 140 * if (off > 0) menas that 'imm' was added 141 */ 142 PTR_TO_PACKET, 143 PTR_TO_PACKET_END, /* skb->data + headlen */ 144 145 /* PTR_TO_MAP_VALUE_ADJ is used for doing pointer math inside of a map 146 * elem value. We only allow this if we can statically verify that 147 * access from this register are going to fall within the size of the 148 * map element. 149 */ 150 PTR_TO_MAP_VALUE_ADJ, 151 }; 152 153 struct bpf_prog; 154 155 struct bpf_verifier_ops { 156 /* return eBPF function prototype for verification */ 157 const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id); 158 159 /* return true if 'size' wide access at offset 'off' within bpf_context 160 * with 'type' (read or write) is allowed 161 */ 162 bool (*is_valid_access)(int off, int size, enum bpf_access_type type, 163 enum bpf_reg_type *reg_type); 164 int (*gen_prologue)(struct bpf_insn *insn, bool direct_write, 165 const struct bpf_prog *prog); 166 u32 (*convert_ctx_access)(enum bpf_access_type type, 167 const struct bpf_insn *src, 168 struct bpf_insn *dst, 169 struct bpf_prog *prog); 170 }; 171 172 struct bpf_prog_type_list { 173 struct list_head list_node; 174 const struct bpf_verifier_ops *ops; 175 enum bpf_prog_type type; 176 }; 177 178 struct bpf_prog_aux { 179 atomic_t refcnt; 180 u32 used_map_cnt; 181 u32 max_ctx_offset; 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 #ifdef CONFIG_BPF_SYSCALL 235 DECLARE_PER_CPU(int, bpf_prog_active); 236 237 void bpf_register_prog_type(struct bpf_prog_type_list *tl); 238 void bpf_register_map_type(struct bpf_map_type_list *tl); 239 240 struct bpf_prog *bpf_prog_get(u32 ufd); 241 struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type); 242 struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, int i); 243 void bpf_prog_sub(struct bpf_prog *prog, int i); 244 struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog); 245 void bpf_prog_put(struct bpf_prog *prog); 246 int __bpf_prog_charge(struct user_struct *user, u32 pages); 247 void __bpf_prog_uncharge(struct user_struct *user, u32 pages); 248 249 struct bpf_map *bpf_map_get_with_uref(u32 ufd); 250 struct bpf_map *__bpf_map_get(struct fd f); 251 struct bpf_map * __must_check bpf_map_inc(struct bpf_map *map, bool uref); 252 void bpf_map_put_with_uref(struct bpf_map *map); 253 void bpf_map_put(struct bpf_map *map); 254 int bpf_map_precharge_memlock(u32 pages); 255 void *bpf_map_area_alloc(size_t size); 256 void bpf_map_area_free(void *base); 257 258 extern int sysctl_unprivileged_bpf_disabled; 259 260 int bpf_map_new_fd(struct bpf_map *map); 261 int bpf_prog_new_fd(struct bpf_prog *prog); 262 263 int bpf_obj_pin_user(u32 ufd, const char __user *pathname); 264 int bpf_obj_get_user(const char __user *pathname); 265 266 int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value); 267 int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value); 268 int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value, 269 u64 flags); 270 int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, 271 u64 flags); 272 273 int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value); 274 275 int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, 276 void *key, void *value, u64 map_flags); 277 void bpf_fd_array_map_clear(struct bpf_map *map); 278 279 /* memcpy that is used with 8-byte aligned pointers, power-of-8 size and 280 * forced to use 'long' read/writes to try to atomically copy long counters. 281 * Best-effort only. No barriers here, since it _will_ race with concurrent 282 * updates from BPF programs. Called from bpf syscall and mostly used with 283 * size 8 or 16 bytes, so ask compiler to inline it. 284 */ 285 static inline void bpf_long_memcpy(void *dst, const void *src, u32 size) 286 { 287 const long *lsrc = src; 288 long *ldst = dst; 289 290 size /= sizeof(long); 291 while (size--) 292 *ldst++ = *lsrc++; 293 } 294 295 /* verify correctness of eBPF program */ 296 int bpf_check(struct bpf_prog **fp, union bpf_attr *attr); 297 #else 298 static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl) 299 { 300 } 301 302 static inline struct bpf_prog *bpf_prog_get(u32 ufd) 303 { 304 return ERR_PTR(-EOPNOTSUPP); 305 } 306 307 static inline struct bpf_prog *bpf_prog_get_type(u32 ufd, 308 enum bpf_prog_type type) 309 { 310 return ERR_PTR(-EOPNOTSUPP); 311 } 312 static inline struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, 313 int i) 314 { 315 return ERR_PTR(-EOPNOTSUPP); 316 } 317 318 static inline void bpf_prog_sub(struct bpf_prog *prog, int i) 319 { 320 } 321 322 static inline void bpf_prog_put(struct bpf_prog *prog) 323 { 324 } 325 326 static inline struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog) 327 { 328 return ERR_PTR(-EOPNOTSUPP); 329 } 330 331 static inline int __bpf_prog_charge(struct user_struct *user, u32 pages) 332 { 333 return 0; 334 } 335 336 static inline void __bpf_prog_uncharge(struct user_struct *user, u32 pages) 337 { 338 } 339 #endif /* CONFIG_BPF_SYSCALL */ 340 341 /* verifier prototypes for helper functions called from eBPF programs */ 342 extern const struct bpf_func_proto bpf_map_lookup_elem_proto; 343 extern const struct bpf_func_proto bpf_map_update_elem_proto; 344 extern const struct bpf_func_proto bpf_map_delete_elem_proto; 345 346 extern const struct bpf_func_proto bpf_get_prandom_u32_proto; 347 extern const struct bpf_func_proto bpf_get_smp_processor_id_proto; 348 extern const struct bpf_func_proto bpf_get_numa_node_id_proto; 349 extern const struct bpf_func_proto bpf_tail_call_proto; 350 extern const struct bpf_func_proto bpf_ktime_get_ns_proto; 351 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto; 352 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto; 353 extern const struct bpf_func_proto bpf_get_current_comm_proto; 354 extern const struct bpf_func_proto bpf_skb_vlan_push_proto; 355 extern const struct bpf_func_proto bpf_skb_vlan_pop_proto; 356 extern const struct bpf_func_proto bpf_get_stackid_proto; 357 358 /* Shared helpers among cBPF and eBPF. */ 359 void bpf_user_rnd_init_once(void); 360 u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 361 362 #endif /* _LINUX_BPF_H */ 363