diff options
author | Alexei Starovoitov <ast@plumgrid.com> | 2014-09-26 00:16:57 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-09-26 15:05:14 -0400 |
commit | 99c55f7d47c0dc6fc64729f37bf435abf43f4c60 (patch) | |
tree | 12f09f26bee9813ae33cfc195582c41e94b2e4e9 /include/linux/bpf.h | |
parent | 4a8e320c929991c9480a7b936512c57ea02d87b2 (diff) |
bpf: introduce BPF syscall and maps
BPF syscall is a multiplexor for a range of different operations on eBPF.
This patch introduces syscall with single command to create a map.
Next patch adds commands to access maps.
'maps' is a generic storage of different types for sharing data between kernel
and userspace.
Userspace example:
/* this syscall wrapper creates a map with given type and attributes
* and returns map_fd on success.
* use close(map_fd) to delete the map
*/
int bpf_create_map(enum bpf_map_type map_type, int key_size,
int value_size, int max_entries)
{
union bpf_attr attr = {
.map_type = map_type,
.key_size = key_size,
.value_size = value_size,
.max_entries = max_entries
};
return bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
}
'union bpf_attr' is backwards compatible with future extensions.
More details in Documentation/networking/filter.txt and in manpage
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/bpf.h')
-rw-r--r-- | include/linux/bpf.h | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h new file mode 100644 index 000000000000..48014a71f0fe --- /dev/null +++ b/include/linux/bpf.h @@ -0,0 +1,41 @@ +/* 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> + +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 *); +}; + +struct bpf_map { + atomic_t refcnt; + enum bpf_map_type map_type; + u32 key_size; + u32 value_size; + u32 max_entries; + struct bpf_map_ops *ops; + struct work_struct work; +}; + +struct bpf_map_type_list { + struct list_head list_node; + struct bpf_map_ops *ops; + enum bpf_map_type type; +}; + +void bpf_register_map_type(struct bpf_map_type_list *tl); +void bpf_map_put(struct bpf_map *map); + +#endif /* _LINUX_BPF_H */ |