diff options
Diffstat (limited to 'kernel/include/linux/bpf.h')
| -rw-r--r-- | kernel/include/linux/bpf.h | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/kernel/include/linux/bpf.h b/kernel/include/linux/bpf.h new file mode 100644 index 000000000..d5cda0671 --- /dev/null +++ b/kernel/include/linux/bpf.h @@ -0,0 +1,164 @@ +/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ +#ifndef _LINUX_BPF_H +#define _LINUX_BPF_H 1 + +#include <uapi/linux/bpf.h> +#include <linux/workqueue.h> +#include <linux/file.h> + +struct bpf_map; + +/* map is generic key/value storage optionally accesible by eBPF programs */ +struct bpf_map_ops { + /* funcs callable from userspace (via syscall) */ + struct bpf_map *(*map_alloc)(union bpf_attr *attr); + void (*map_free)(struct bpf_map *); + int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key); + + /* funcs callable from userspace and from eBPF programs */ + void *(*map_lookup_elem)(struct bpf_map *map, void *key); + int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags); + int (*map_delete_elem)(struct bpf_map *map, void *key); +}; + +struct bpf_map { + atomic_t refcnt; + enum bpf_map_type map_type; + u32 key_size; + u32 value_size; + u32 max_entries; + const struct bpf_map_ops *ops; + struct work_struct work; +}; + +struct bpf_map_type_list { + struct list_head list_node; + const struct bpf_map_ops *ops; + enum bpf_map_type type; +}; + +/* function argument constraints */ +enum bpf_arg_type { + ARG_DONTCARE = 0, /* unused argument in helper function */ + + /* the following constraints used to prototype + * bpf_map_lookup/update/delete_elem() functions + */ + ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */ + ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */ + ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */ + + /* the following constraints used to prototype bpf_memcmp() and other + * functions that access data on eBPF program stack + */ + ARG_PTR_TO_STACK, /* any pointer to eBPF program stack */ + ARG_CONST_STACK_SIZE, /* number of bytes accessed from stack */ + + ARG_PTR_TO_CTX, /* pointer to context */ + ARG_ANYTHING, /* any (initialized) argument is ok */ +}; + +/* type of values returned from helper functions */ +enum bpf_return_type { + RET_INTEGER, /* function returns integer */ + RET_VOID, /* function doesn't return anything */ + RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */ +}; + +/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs + * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL + * instructions after verifying + */ +struct bpf_func_proto { + u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); + bool gpl_only; + enum bpf_return_type ret_type; + enum bpf_arg_type arg1_type; + enum bpf_arg_type arg2_type; + enum bpf_arg_type arg3_type; + enum bpf_arg_type arg4_type; + enum bpf_arg_type arg5_type; +}; + +/* bpf_context is intentionally undefined structure. Pointer to bpf_context is + * the first argument to eBPF programs. + * For socket filters: 'struct bpf_context *' == 'struct sk_buff *' + */ +struct bpf_context; + +enum bpf_access_type { + BPF_READ = 1, + BPF_WRITE = 2 +}; + +struct bpf_verifier_ops { + /* return eBPF function prototype for verification */ + const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id); + + /* return true if 'size' wide access at offset 'off' within bpf_context + * with 'type' (read or write) is allowed + */ + bool (*is_valid_access)(int off, int size, enum bpf_access_type type); + + u32 (*convert_ctx_access)(int dst_reg, int src_reg, int ctx_off, + struct bpf_insn *insn); +}; + +struct bpf_prog_type_list { + struct list_head list_node; + const struct bpf_verifier_ops *ops; + enum bpf_prog_type type; +}; + +struct bpf_prog; + +struct bpf_prog_aux { + atomic_t refcnt; + u32 used_map_cnt; + const struct bpf_verifier_ops *ops; + struct bpf_map **used_maps; + struct bpf_prog *prog; + struct work_struct work; +}; + +#ifdef CONFIG_BPF_SYSCALL +void bpf_register_prog_type(struct bpf_prog_type_list *tl); +void bpf_register_map_type(struct bpf_map_type_list *tl); + +struct bpf_prog *bpf_prog_get(u32 ufd); +void bpf_prog_put(struct bpf_prog *prog); + +struct bpf_map *bpf_map_get(struct fd f); +void bpf_map_put(struct bpf_map *map); + +/* verify correctness of eBPF program */ +int bpf_check(struct bpf_prog **fp, union bpf_attr *attr); +#else +static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl) +{ +} + +static inline struct bpf_prog *bpf_prog_get(u32 ufd) +{ + return ERR_PTR(-EOPNOTSUPP); +} + +static inline void bpf_prog_put(struct bpf_prog *prog) +{ +} +#endif /* CONFIG_BPF_SYSCALL */ + +/* verifier prototypes for helper functions called from eBPF programs */ +extern const struct bpf_func_proto bpf_map_lookup_elem_proto; +extern const struct bpf_func_proto bpf_map_update_elem_proto; +extern const struct bpf_func_proto bpf_map_delete_elem_proto; + +extern const struct bpf_func_proto bpf_get_prandom_u32_proto; +extern const struct bpf_func_proto bpf_get_smp_processor_id_proto; + +#endif /* _LINUX_BPF_H */ |