diff options
Diffstat (limited to 'include/linux/bpf.h')
| -rw-r--r-- | include/linux/bpf.h | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h new file mode 100644 index 000000000000..bae3da5bcda0 --- /dev/null +++ b/include/linux/bpf.h @@ -0,0 +1,231 @@ +/* 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); + + /* funcs called by prog_array and perf_event_array map */ + void *(*map_fd_get_ptr) (struct bpf_map *map, int fd); + void (*map_fd_put_ptr) (void *ptr); +}; + +struct bpf_map { + /* 1st cacheline with read-mostly members of which some + * are also accessed in fast-path (e.g. ops, max_entries). + */ + const struct bpf_map_ops *ops ____cacheline_aligned; + enum bpf_map_type map_type; + u32 key_size; + u32 value_size; + u32 max_entries; + u32 pages; + bool unpriv_array; + /* 7 bytes hole */ + + /* 2nd cacheline with misc members to avoid false sharing + * particularly with refcounting. + */ + struct user_struct *user ____cacheline_aligned; + atomic_t refcnt; + atomic_t usercnt; + 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_prog; + +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)(enum bpf_access_type type, int dst_reg, + int src_reg, int ctx_off, + struct bpf_insn *insn, struct bpf_prog *prog); +}; + +struct bpf_prog_type_list { + struct list_head list_node; + const struct bpf_verifier_ops *ops; + enum bpf_prog_type type; +}; + +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 user_struct *user; + union { + struct work_struct work; + struct rcu_head rcu; + }; +}; + +struct bpf_array { + struct bpf_map map; + u32 elem_size; + u32 index_mask; + /* 'ownership' of prog_array is claimed by the first program that + * is going to use this map or by the first program which FD is stored + * in the map to make sure that all callers and callees have the same + * prog_type and JITed flag + */ + enum bpf_prog_type owner_prog_type; + bool owner_jited; + union { + char value[0] __aligned(8); + void *ptrs[0] __aligned(8); + }; +}; +#define MAX_TAIL_CALL_CNT 32 + +u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5); +void bpf_fd_array_map_clear(struct bpf_map *map); +bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp); +const struct bpf_func_proto *bpf_get_trace_printk_proto(void); + +#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); +struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog); +void bpf_prog_put(struct bpf_prog *prog); + +struct bpf_map *bpf_map_get_with_uref(u32 ufd); +struct bpf_map *__bpf_map_get(struct fd f); +struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref); +void bpf_map_put_with_uref(struct bpf_map *map); +void bpf_map_put(struct bpf_map *map); + +extern int sysctl_unprivileged_bpf_disabled; + +int bpf_map_new_fd(struct bpf_map *map); +int bpf_prog_new_fd(struct bpf_prog *prog); + +int bpf_obj_pin_user(u32 ufd, const char __user *pathname); +int bpf_obj_get_user(const char __user *pathname); + +/* 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; +extern const struct bpf_func_proto bpf_tail_call_proto; +extern const struct bpf_func_proto bpf_ktime_get_ns_proto; +extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto; +extern const struct bpf_func_proto bpf_get_current_uid_gid_proto; +extern const struct bpf_func_proto bpf_get_current_comm_proto; +extern const struct bpf_func_proto bpf_skb_vlan_push_proto; +extern const struct bpf_func_proto bpf_skb_vlan_pop_proto; + +/* Shared helpers among cBPF and eBPF. */ +void bpf_user_rnd_init_once(void); +u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); + +#endif /* _LINUX_BPF_H */ |