Commit e981f41f authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

libbpf: Open code low level bpf commands. 



Open code low level bpf commands used by light skeleton to
be able to avoid full libbpf eventually.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220131220528.98088-3-alexei.starovoitov@gmail.com
parent 42d1d53f

tools/lib/bpf/skel_internal.h

+42 −2
Original line number Diff line number Diff line
@@ -70,19 +70,59 @@ static inline int skel_closenz(int fd) 
	return -EINVAL;

}



#ifndef offsetofend

#define offsetofend(TYPE, MEMBER) \

	(offsetof(TYPE, MEMBER)	+ sizeof((((TYPE *)0)->MEMBER)))

#endif



static inline int skel_map_create(enum bpf_map_type map_type,

				  const char *map_name,

				  __u32 key_size,

				  __u32 value_size,

				  __u32 max_entries)

{

	const size_t attr_sz = offsetofend(union bpf_attr, map_extra);

	union bpf_attr attr;



	memset(&attr, 0, attr_sz);



	attr.map_type = map_type;

	strncpy(attr.map_name, map_name, sizeof(attr.map_name));

	attr.key_size = key_size;

	attr.value_size = value_size;

	attr.max_entries = max_entries;



	return skel_sys_bpf(BPF_MAP_CREATE, &attr, attr_sz);

}



static inline int skel_map_update_elem(int fd, const void *key,

				       const void *value, __u64 flags)

{

	const size_t attr_sz = offsetofend(union bpf_attr, flags);

	union bpf_attr attr;



	memset(&attr, 0, attr_sz);

	attr.map_fd = fd;

	attr.key = (long) key;

	attr.value = (long) value;

	attr.flags = flags;



	return skel_sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, attr_sz);

}



static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)

{

	int map_fd = -1, prog_fd = -1, key = 0, err;

	union bpf_attr attr;



	map_fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, "__loader.map", 4, opts->data_sz, 1, NULL);

	map_fd = skel_map_create(BPF_MAP_TYPE_ARRAY, "__loader.map", 4, opts->data_sz, 1);

	if (map_fd < 0) {

		opts->errstr = "failed to create loader map";

		err = -errno;

		goto out;

	}



	err = bpf_map_update_elem(map_fd, &key, opts->data, 0);

	err = skel_map_update_elem(map_fd, &key, opts->data, 0);

	if (err < 0) {

		opts->errstr = "failed to update loader map";

		err = -errno;