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.
7 * This program is distributed in the hope that it will be useful, but
8 * WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
10 * General Public License for more details.
12 #include <linux/bpf.h>
13 #include <linux/rcupdate.h>
14 #include <linux/random.h>
15 #include <linux/smp.h>
16 #include <linux/ktime.h>
18 /* If kernel subsystem is allowing eBPF programs to call this function,
19 * inside its own verifier_ops->get_func_proto() callback it should return
20 * bpf_map_lookup_elem_proto, so that verifier can properly check the arguments
22 * Different map implementations will rely on rcu in map methods
23 * lookup/update/delete, therefore eBPF programs must run under rcu lock
24 * if program is allowed to access maps, so check rcu_read_lock_held in
25 * all three functions.
27 static u64 bpf_map_lookup_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
29 /* verifier checked that R1 contains a valid pointer to bpf_map
30 * and R2 points to a program stack and map->key_size bytes were
33 struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
34 void *key = (void *) (unsigned long) r2;
37 WARN_ON_ONCE(!rcu_read_lock_held());
39 value = map->ops->map_lookup_elem(map, key);
41 /* lookup() returns either pointer to element value or NULL
42 * which is the meaning of PTR_TO_MAP_VALUE_OR_NULL type
44 return (unsigned long) value;
47 const struct bpf_func_proto bpf_map_lookup_elem_proto = {
48 .func = bpf_map_lookup_elem,
50 .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
51 .arg1_type = ARG_CONST_MAP_PTR,
52 .arg2_type = ARG_PTR_TO_MAP_KEY,
55 static u64 bpf_map_update_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
57 struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
58 void *key = (void *) (unsigned long) r2;
59 void *value = (void *) (unsigned long) r3;
61 WARN_ON_ONCE(!rcu_read_lock_held());
63 return map->ops->map_update_elem(map, key, value, r4);
66 const struct bpf_func_proto bpf_map_update_elem_proto = {
67 .func = bpf_map_update_elem,
69 .ret_type = RET_INTEGER,
70 .arg1_type = ARG_CONST_MAP_PTR,
71 .arg2_type = ARG_PTR_TO_MAP_KEY,
72 .arg3_type = ARG_PTR_TO_MAP_VALUE,
73 .arg4_type = ARG_ANYTHING,
76 static u64 bpf_map_delete_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
78 struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
79 void *key = (void *) (unsigned long) r2;
81 WARN_ON_ONCE(!rcu_read_lock_held());
83 return map->ops->map_delete_elem(map, key);
86 const struct bpf_func_proto bpf_map_delete_elem_proto = {
87 .func = bpf_map_delete_elem,
89 .ret_type = RET_INTEGER,
90 .arg1_type = ARG_CONST_MAP_PTR,
91 .arg2_type = ARG_PTR_TO_MAP_KEY,
94 static u64 bpf_get_prandom_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
99 const struct bpf_func_proto bpf_get_prandom_u32_proto = {
100 .func = bpf_get_prandom_u32,
102 .ret_type = RET_INTEGER,
105 static u64 bpf_get_smp_processor_id(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
107 return raw_smp_processor_id();
110 const struct bpf_func_proto bpf_get_smp_processor_id_proto = {
111 .func = bpf_get_smp_processor_id,
113 .ret_type = RET_INTEGER,
116 static u64 bpf_ktime_get_ns(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
118 /* NMI safe access to clock monotonic */
119 return ktime_get_mono_fast_ns();
122 const struct bpf_func_proto bpf_ktime_get_ns_proto = {
123 .func = bpf_ktime_get_ns,
125 .ret_type = RET_INTEGER,