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: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220131220528.98088-3-alexei.starovoitov@gmail.com
This commit is contained in:
Alexei Starovoitov 2022-01-31 14:05:23 -08:00 committed by Daniel Borkmann
parent 42d1d53fed
commit e981f41fd0
1 changed files with 42 additions and 2 deletions

View File

@ -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;