1 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
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.
10 #include <uapi/linux/bpf.h>
11 #include <linux/workqueue.h>
12 #include <linux/file.h>
16 /* map is generic key/value storage optionally accesible by eBPF programs */
18 /* funcs callable from userspace (via syscall) */
19 struct bpf_map *(*map_alloc)(union bpf_attr *attr);
20 void (*map_free)(struct bpf_map *);
21 int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key);
23 /* funcs callable from userspace and from eBPF programs */
24 void *(*map_lookup_elem)(struct bpf_map *map, void *key);
25 int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags);
26 int (*map_delete_elem)(struct bpf_map *map, void *key);
28 /* funcs called by prog_array and perf_event_array map */
29 void *(*map_fd_get_ptr) (struct bpf_map *map, int fd);
30 void (*map_fd_put_ptr) (void *ptr);
35 enum bpf_map_type map_type;
39 const struct bpf_map_ops *ops;
40 struct work_struct work;
43 struct bpf_map_type_list {
44 struct list_head list_node;
45 const struct bpf_map_ops *ops;
46 enum bpf_map_type type;
49 /* function argument constraints */
51 ARG_DONTCARE = 0, /* unused argument in helper function */
53 /* the following constraints used to prototype
54 * bpf_map_lookup/update/delete_elem() functions
56 ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */
57 ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */
58 ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */
60 /* the following constraints used to prototype bpf_memcmp() and other
61 * functions that access data on eBPF program stack
63 ARG_PTR_TO_STACK, /* any pointer to eBPF program stack */
64 ARG_CONST_STACK_SIZE, /* number of bytes accessed from stack */
66 ARG_PTR_TO_CTX, /* pointer to context */
67 ARG_ANYTHING, /* any (initialized) argument is ok */
70 /* type of values returned from helper functions */
71 enum bpf_return_type {
72 RET_INTEGER, /* function returns integer */
73 RET_VOID, /* function doesn't return anything */
74 RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */
77 /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
78 * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
79 * instructions after verifying
81 struct bpf_func_proto {
82 u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
84 enum bpf_return_type ret_type;
85 enum bpf_arg_type arg1_type;
86 enum bpf_arg_type arg2_type;
87 enum bpf_arg_type arg3_type;
88 enum bpf_arg_type arg4_type;
89 enum bpf_arg_type arg5_type;
92 /* bpf_context is intentionally undefined structure. Pointer to bpf_context is
93 * the first argument to eBPF programs.
94 * For socket filters: 'struct bpf_context *' == 'struct sk_buff *'
98 enum bpf_access_type {
103 struct bpf_verifier_ops {
104 /* return eBPF function prototype for verification */
105 const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id);
107 /* return true if 'size' wide access at offset 'off' within bpf_context
108 * with 'type' (read or write) is allowed
110 bool (*is_valid_access)(int off, int size, enum bpf_access_type type);
112 u32 (*convert_ctx_access)(enum bpf_access_type type, int dst_reg,
113 int src_reg, int ctx_off,
114 struct bpf_insn *insn);
117 struct bpf_prog_type_list {
118 struct list_head list_node;
119 const struct bpf_verifier_ops *ops;
120 enum bpf_prog_type type;
125 struct bpf_prog_aux {
128 const struct bpf_verifier_ops *ops;
129 struct bpf_map **used_maps;
130 struct bpf_prog *prog;
132 struct work_struct work;
140 /* 'ownership' of prog_array is claimed by the first program that
141 * is going to use this map or by the first program which FD is stored
142 * in the map to make sure that all callers and callees have the same
143 * prog_type and JITed flag
145 enum bpf_prog_type owner_prog_type;
148 char value[0] __aligned(8);
149 void *ptrs[0] __aligned(8);
152 #define MAX_TAIL_CALL_CNT 32
154 u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
155 void bpf_fd_array_map_clear(struct bpf_map *map);
156 bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp);
157 const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
159 #ifdef CONFIG_BPF_SYSCALL
160 void bpf_register_prog_type(struct bpf_prog_type_list *tl);
161 void bpf_register_map_type(struct bpf_map_type_list *tl);
163 struct bpf_prog *bpf_prog_get(u32 ufd);
164 void bpf_prog_put(struct bpf_prog *prog);
165 void bpf_prog_put_rcu(struct bpf_prog *prog);
167 struct bpf_map *bpf_map_get(struct fd f);
168 void bpf_map_put(struct bpf_map *map);
170 /* verify correctness of eBPF program */
171 int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
173 static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl)
177 static inline struct bpf_prog *bpf_prog_get(u32 ufd)
179 return ERR_PTR(-EOPNOTSUPP);
182 static inline void bpf_prog_put(struct bpf_prog *prog)
185 #endif /* CONFIG_BPF_SYSCALL */
187 /* verifier prototypes for helper functions called from eBPF programs */
188 extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
189 extern const struct bpf_func_proto bpf_map_update_elem_proto;
190 extern const struct bpf_func_proto bpf_map_delete_elem_proto;
192 extern const struct bpf_func_proto bpf_perf_event_read_proto;
193 extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
194 extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
195 extern const struct bpf_func_proto bpf_tail_call_proto;
196 extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
197 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
198 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
199 extern const struct bpf_func_proto bpf_get_current_comm_proto;
200 extern const struct bpf_func_proto bpf_skb_vlan_push_proto;
201 extern const struct bpf_func_proto bpf_skb_vlan_pop_proto;
203 /* Shared helpers among cBPF and eBPF. */
204 void bpf_user_rnd_init_once(void);
205 u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
207 #endif /* _LINUX_BPF_H */