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libbpf: Add opts-based attach/detach/query API for tcx

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Extend libbpf attach opts and add a new detach opts API so this can be used
to add/remove fd-based tcx BPF programs. The old-style bpf_prog_detach() and
bpf_prog_detach2() APIs are refactored to reuse the new bpf_prog_detach_opts()
internally.

The bpf_prog_query_opts() API got extended to be able to handle the new
link_ids, link_attach_flags and revision fields.

For concrete usage examples, see the extensive selftests that have been
developed as part of this series.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230719140858.13224-4-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Daniel Borkmann
2023-07-19 16:08:53 +02:00
committed by Alexei Starovoitov
parent e420bed025
commit fe20ce3a51
4 changed files with 159 additions and 53 deletions
Download Patch File Download Diff File Expand all files Collapse all files

107
tools/lib/bpf/bpf.c
View File

@ -629,55 +629,89 @@ int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
return bpf_prog_attach_opts(prog_fd, target_fd, type, &opts);
}
int bpf_prog_attach_opts(int prog_fd, int target_fd,
enum bpf_attach_type type,
const struct bpf_prog_attach_opts *opts)
int bpf_prog_attach_opts(int prog_fd, int target, enum bpf_attach_type type,
const struct bpf_prog_attach_opts *opts)
{
const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd);
const size_t attr_sz = offsetofend(union bpf_attr, expected_revision);
__u32 relative_id, flags;
int ret, relative_fd;
union bpf_attr attr;
int ret;
if (!OPTS_VALID(opts, bpf_prog_attach_opts))
return libbpf_err(-EINVAL);
relative_id = OPTS_GET(opts, relative_id, 0);
relative_fd = OPTS_GET(opts, relative_fd, 0);
flags = OPTS_GET(opts, flags, 0);
/* validate we don't have unexpected combinations of non-zero fields */
if (relative_fd && relative_id)
return libbpf_err(-EINVAL);
memset(&attr, 0, attr_sz);
attr.target_fd = target_fd;
attr.attach_bpf_fd = prog_fd;
attr.attach_type = type;
attr.attach_flags = OPTS_GET(opts, flags, 0);
attr.replace_bpf_fd = OPTS_GET(opts, replace_prog_fd, 0);
attr.target_fd = target;
attr.attach_bpf_fd = prog_fd;
attr.attach_type = type;
attr.replace_bpf_fd = OPTS_GET(opts, replace_fd, 0);
attr.expected_revision = OPTS_GET(opts, expected_revision, 0);
if (relative_id) {
attr.attach_flags = flags | BPF_F_ID;
attr.relative_id = relative_id;
} else {
attr.attach_flags = flags;
attr.relative_fd = relative_fd;
}
ret = sys_bpf(BPF_PROG_ATTACH, &attr, attr_sz);
return libbpf_err_errno(ret);
}
int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
int bpf_prog_detach_opts(int prog_fd, int target, enum bpf_attach_type type,
const struct bpf_prog_detach_opts *opts)
{
const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd);
const size_t attr_sz = offsetofend(union bpf_attr, expected_revision);
__u32 relative_id, flags;
int ret, relative_fd;
union bpf_attr attr;
int ret;
if (!OPTS_VALID(opts, bpf_prog_detach_opts))
return libbpf_err(-EINVAL);
relative_id = OPTS_GET(opts, relative_id, 0);
relative_fd = OPTS_GET(opts, relative_fd, 0);
flags = OPTS_GET(opts, flags, 0);
/* validate we don't have unexpected combinations of non-zero fields */
if (relative_fd && relative_id)
return libbpf_err(-EINVAL);
memset(&attr, 0, attr_sz);
attr.target_fd = target_fd;
attr.attach_type = type;
attr.target_fd = target;
attr.attach_bpf_fd = prog_fd;
attr.attach_type = type;
attr.expected_revision = OPTS_GET(opts, expected_revision, 0);
if (relative_id) {
attr.attach_flags = flags | BPF_F_ID;
attr.relative_id = relative_id;
} else {
attr.attach_flags = flags;
attr.relative_fd = relative_fd;
}
ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz);
return libbpf_err_errno(ret);
}
int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
{
return bpf_prog_detach_opts(0, target_fd, type, NULL);
}
int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type)
{
const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd);
union bpf_attr attr;
int ret;
memset(&attr, 0, attr_sz);
attr.target_fd = target_fd;
attr.attach_bpf_fd = prog_fd;
attr.attach_type = type;
ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz);
return libbpf_err_errno(ret);
return bpf_prog_detach_opts(prog_fd, target_fd, type, NULL);
}
int bpf_link_create(int prog_fd, int target_fd,
@ -841,8 +875,7 @@ int bpf_iter_create(int link_fd)
return libbpf_err_errno(fd);
}
int bpf_prog_query_opts(int target_fd,
enum bpf_attach_type type,
int bpf_prog_query_opts(int target, enum bpf_attach_type type,
struct bpf_prog_query_opts *opts)
{
const size_t attr_sz = offsetofend(union bpf_attr, query);
@ -853,18 +886,20 @@ int bpf_prog_query_opts(int target_fd,
return libbpf_err(-EINVAL);
memset(&attr, 0, attr_sz);
attr.query.target_fd = target_fd;
attr.query.attach_type = type;
attr.query.query_flags = OPTS_GET(opts, query_flags, 0);
attr.query.prog_cnt = OPTS_GET(opts, prog_cnt, 0);
attr.query.prog_ids = ptr_to_u64(OPTS_GET(opts, prog_ids, NULL));
attr.query.prog_attach_flags = ptr_to_u64(OPTS_GET(opts, prog_attach_flags, NULL));
attr.query.target_fd = target;
attr.query.attach_type = type;
attr.query.query_flags = OPTS_GET(opts, query_flags, 0);
attr.query.count = OPTS_GET(opts, count, 0);
attr.query.prog_ids = ptr_to_u64(OPTS_GET(opts, prog_ids, NULL));
attr.query.link_ids = ptr_to_u64(OPTS_GET(opts, link_ids, NULL));
attr.query.prog_attach_flags = ptr_to_u64(OPTS_GET(opts, prog_attach_flags, NULL));
attr.query.link_attach_flags = ptr_to_u64(OPTS_GET(opts, link_attach_flags, NULL));
ret = sys_bpf(BPF_PROG_QUERY, &attr, attr_sz);
OPTS_SET(opts, attach_flags, attr.query.attach_flags);
OPTS_SET(opts, prog_cnt, attr.query.prog_cnt);
OPTS_SET(opts, revision, attr.query.revision);
OPTS_SET(opts, count, attr.query.count);
return libbpf_err_errno(ret);
}