372 lines
12 KiB
C
372 lines
12 KiB
C
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/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*/
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#ifndef _LINUX_BPF_H
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#define _LINUX_BPF_H 1
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#include <uapi/linux/bpf.h>
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#include <linux/workqueue.h>
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#include <linux/file.h>
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#include <linux/percpu.h>
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#include <linux/err.h>
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struct perf_event;
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struct bpf_map;
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/* map is generic key/value storage optionally accesible by eBPF programs */
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struct bpf_map_ops {
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/* funcs callable from userspace (via syscall) */
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struct bpf_map *(*map_alloc)(union bpf_attr *attr);
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void (*map_release)(struct bpf_map *map, struct file *map_file);
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void (*map_free)(struct bpf_map *map);
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int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key);
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/* funcs callable from userspace and from eBPF programs */
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void *(*map_lookup_elem)(struct bpf_map *map, void *key);
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int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags);
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int (*map_delete_elem)(struct bpf_map *map, void *key);
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/* funcs called by prog_array and perf_event_array map */
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void *(*map_fd_get_ptr)(struct bpf_map *map, struct file *map_file,
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int fd);
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void (*map_fd_put_ptr)(void *ptr);
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};
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struct bpf_map {
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/* 1st cacheline with read-mostly members of which some
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* are also accessed in fast-path (e.g. ops, max_entries).
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*/
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const struct bpf_map_ops *ops ____cacheline_aligned;
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enum bpf_map_type map_type;
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u32 key_size;
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u32 value_size;
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u32 max_entries;
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u32 map_flags;
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u32 pages;
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bool unpriv_array;
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/* 7 bytes hole */
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/* 2nd cacheline with misc members to avoid false sharing
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* particularly with refcounting.
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*/
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struct user_struct *user ____cacheline_aligned;
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atomic_t refcnt;
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atomic_t usercnt;
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struct work_struct work;
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#ifdef CONFIG_SECURITY
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void *security;
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#endif
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};
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struct bpf_map_type_list {
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struct list_head list_node;
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const struct bpf_map_ops *ops;
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enum bpf_map_type type;
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};
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/* function argument constraints */
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enum bpf_arg_type {
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ARG_DONTCARE = 0, /* unused argument in helper function */
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/* the following constraints used to prototype
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* bpf_map_lookup/update/delete_elem() functions
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*/
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ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */
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ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */
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ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */
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/* the following constraints used to prototype bpf_memcmp() and other
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* functions that access data on eBPF program stack
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*/
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ARG_PTR_TO_STACK, /* any pointer to eBPF program stack */
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ARG_PTR_TO_RAW_STACK, /* any pointer to eBPF program stack, area does not
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* need to be initialized, helper function must fill
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* all bytes or clear them in error case.
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*/
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ARG_CONST_STACK_SIZE, /* number of bytes accessed from stack */
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ARG_CONST_STACK_SIZE_OR_ZERO, /* number of bytes accessed from stack or 0 */
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ARG_PTR_TO_CTX, /* pointer to context */
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ARG_ANYTHING, /* any (initialized) argument is ok */
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};
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/* type of values returned from helper functions */
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enum bpf_return_type {
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RET_INTEGER, /* function returns integer */
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RET_VOID, /* function doesn't return anything */
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RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */
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};
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/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
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* to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
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* instructions after verifying
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*/
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struct bpf_func_proto {
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u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
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bool gpl_only;
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bool pkt_access;
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enum bpf_return_type ret_type;
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enum bpf_arg_type arg1_type;
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enum bpf_arg_type arg2_type;
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enum bpf_arg_type arg3_type;
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enum bpf_arg_type arg4_type;
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enum bpf_arg_type arg5_type;
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};
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/* bpf_context is intentionally undefined structure. Pointer to bpf_context is
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* the first argument to eBPF programs.
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* For socket filters: 'struct bpf_context *' == 'struct sk_buff *'
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*/
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struct bpf_context;
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enum bpf_access_type {
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BPF_READ = 1,
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BPF_WRITE = 2
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};
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/* types of values stored in eBPF registers */
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enum bpf_reg_type {
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NOT_INIT = 0, /* nothing was written into register */
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UNKNOWN_VALUE, /* reg doesn't contain a valid pointer */
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PTR_TO_CTX, /* reg points to bpf_context */
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CONST_PTR_TO_MAP, /* reg points to struct bpf_map */
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PTR_TO_MAP_VALUE, /* reg points to map element value */
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PTR_TO_MAP_VALUE_OR_NULL,/* points to map elem value or NULL */
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FRAME_PTR, /* reg == frame_pointer */
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PTR_TO_STACK, /* reg == frame_pointer + imm */
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CONST_IMM, /* constant integer value */
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/* PTR_TO_PACKET represents:
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* skb->data
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* skb->data + imm
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* skb->data + (u16) var
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* skb->data + (u16) var + imm
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* if (range > 0) then [ptr, ptr + range - off) is safe to access
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* if (id > 0) means that some 'var' was added
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* if (off > 0) menas that 'imm' was added
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*/
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PTR_TO_PACKET,
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PTR_TO_PACKET_END, /* skb->data + headlen */
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/* PTR_TO_MAP_VALUE_ADJ is used for doing pointer math inside of a map
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* elem value. We only allow this if we can statically verify that
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* access from this register are going to fall within the size of the
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* map element.
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*/
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PTR_TO_MAP_VALUE_ADJ,
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};
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struct bpf_prog;
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struct bpf_verifier_ops {
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/* return eBPF function prototype for verification */
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const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id);
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/* return true if 'size' wide access at offset 'off' within bpf_context
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* with 'type' (read or write) is allowed
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*/
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bool (*is_valid_access)(int off, int size, enum bpf_access_type type,
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enum bpf_reg_type *reg_type);
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int (*gen_prologue)(struct bpf_insn *insn, bool direct_write,
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const struct bpf_prog *prog);
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u32 (*convert_ctx_access)(enum bpf_access_type type, int dst_reg,
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int src_reg, int ctx_off,
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struct bpf_insn *insn, struct bpf_prog *prog);
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};
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struct bpf_prog_type_list {
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struct list_head list_node;
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const struct bpf_verifier_ops *ops;
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enum bpf_prog_type type;
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};
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struct bpf_prog_aux {
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atomic_t refcnt;
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u32 used_map_cnt;
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u32 max_ctx_offset;
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const struct bpf_verifier_ops *ops;
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struct bpf_map **used_maps;
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struct bpf_prog *prog;
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struct user_struct *user;
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#ifdef CONFIG_SECURITY
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void *security;
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#endif
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union {
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struct work_struct work;
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struct rcu_head rcu;
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};
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};
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struct bpf_array {
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struct bpf_map map;
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u32 elem_size;
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u32 index_mask;
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/* 'ownership' of prog_array is claimed by the first program that
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* is going to use this map or by the first program which FD is stored
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* in the map to make sure that all callers and callees have the same
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* prog_type and JITed flag
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*/
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enum bpf_prog_type owner_prog_type;
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bool owner_jited;
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union {
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char value[0] __aligned(8);
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void *ptrs[0] __aligned(8);
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void __percpu *pptrs[0] __aligned(8);
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};
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};
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#define MAX_TAIL_CALL_CNT 32
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struct bpf_event_entry {
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struct perf_event *event;
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struct file *perf_file;
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struct file *map_file;
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struct rcu_head rcu;
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};
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u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
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u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
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bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp);
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const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
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typedef unsigned long (*bpf_ctx_copy_t)(void *dst, const void *src,
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unsigned long off, unsigned long len);
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u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
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void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy);
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#ifdef CONFIG_BPF_SYSCALL
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DECLARE_PER_CPU(int, bpf_prog_active);
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void bpf_register_prog_type(struct bpf_prog_type_list *tl);
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void bpf_register_map_type(struct bpf_map_type_list *tl);
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extern const struct file_operations bpf_map_fops;
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extern const struct file_operations bpf_prog_fops;
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struct bpf_prog *bpf_prog_get(u32 ufd);
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struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type);
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struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i);
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struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog);
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void bpf_prog_put(struct bpf_prog *prog);
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struct bpf_map *bpf_map_get_with_uref(u32 ufd);
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struct bpf_map *__bpf_map_get(struct fd f);
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struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref);
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void bpf_map_put_with_uref(struct bpf_map *map);
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void bpf_map_put(struct bpf_map *map);
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int bpf_map_precharge_memlock(u32 pages);
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void *bpf_map_area_alloc(size_t size);
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void bpf_map_area_free(void *base);
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extern int sysctl_unprivileged_bpf_disabled;
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int bpf_map_new_fd(struct bpf_map *map, int flags);
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int bpf_prog_new_fd(struct bpf_prog *prog);
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int bpf_obj_pin_user(u32 ufd, const char __user *pathname);
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int bpf_obj_get_user(const char __user *pathname, int flags);
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int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value);
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int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value);
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int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
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u64 flags);
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int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
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u64 flags);
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int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value);
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int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
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void *key, void *value, u64 map_flags);
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void bpf_fd_array_map_clear(struct bpf_map *map);
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int bpf_get_file_flag(int flags);
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/* memcpy that is used with 8-byte aligned pointers, power-of-8 size and
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* forced to use 'long' read/writes to try to atomically copy long counters.
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* Best-effort only. No barriers here, since it _will_ race with concurrent
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* updates from BPF programs. Called from bpf syscall and mostly used with
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* size 8 or 16 bytes, so ask compiler to inline it.
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*/
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static inline void bpf_long_memcpy(void *dst, const void *src, u32 size)
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{
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const long *lsrc = src;
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long *ldst = dst;
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size /= sizeof(long);
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while (size--)
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*ldst++ = *lsrc++;
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}
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/* verify correctness of eBPF program */
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int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
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struct bpf_prog *bpf_prog_get_type_path(const char *name, enum bpf_prog_type type);
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#else
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static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl)
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{
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}
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static inline struct bpf_prog *bpf_prog_get(u32 ufd)
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{
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return ERR_PTR(-EOPNOTSUPP);
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}
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static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
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enum bpf_prog_type type)
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{
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return ERR_PTR(-EOPNOTSUPP);
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}
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static inline struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
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{
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return ERR_PTR(-EOPNOTSUPP);
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}
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static inline void bpf_prog_put(struct bpf_prog *prog)
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{
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}
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static inline struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
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{
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return ERR_PTR(-EOPNOTSUPP);
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}
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static inline int bpf_obj_get_user(const char __user *pathname)
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{
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return -EOPNOTSUPP;
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}
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static inline struct bpf_prog *bpf_prog_get_type_path(const char *name,
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enum bpf_prog_type type)
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{
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return ERR_PTR(-EOPNOTSUPP);
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|
|
}
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||
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|
#endif /* CONFIG_BPF_SYSCALL */
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||
|
|
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||
|
|
/* verifier prototypes for helper functions called from eBPF programs */
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||
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|
extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
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||
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|
extern const struct bpf_func_proto bpf_map_update_elem_proto;
|
||
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|
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;
|
||
|
|
extern const struct bpf_func_proto bpf_get_stackid_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 */
|