Introduce bpf_map_get_fd_by_id_opts(), to let the caller pass a
bpf_get_fd_opts structure with flags set to the permissions necessary to
perform the operations on the obtained file descriptor.
Don't check FEAT_GET_FD_BY_ID_OPEN_FLAGS, as current kernels already take
open_flags as last bpf_attr field for this request.
Keep the existing bpf_map_get_fd_by_id(), and call
bpf_map_get_fd_by_id_opts() with NULL as opts argument, to request
read-write permissions.
Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
---
tools/lib/bpf/bpf.c | 12 +++++++++++-
tools/lib/bpf/bpf.h | 2 ++
tools/lib/bpf/libbpf.map | 1 +
3 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 9014a61bca83..4b574ad046f3 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -957,18 +957,28 @@ int bpf_prog_get_fd_by_id(__u32 id)
return bpf_prog_get_fd_by_id_opts(id, NULL);
}
-int bpf_map_get_fd_by_id(__u32 id)
+int bpf_map_get_fd_by_id_opts(__u32 id,
+ const struct bpf_get_fd_opts *opts)
{
union bpf_attr attr;
int fd;
+ if (!OPTS_VALID(opts, bpf_get_fd_opts))
+ return libbpf_err(-EINVAL);
+
memset(&attr, 0, sizeof(attr));
attr.map_id = id;
+ attr.open_flags = OPTS_GET(opts, flags, 0);
fd = sys_bpf_fd(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr));
return libbpf_err_errno(fd);
}
+int bpf_map_get_fd_by_id(__u32 id)
+{
+ return bpf_map_get_fd_by_id_opts(id, NULL);
+}
+
int bpf_btf_get_fd_by_id(__u32 id)
{
union bpf_attr attr;
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index bc241343a0f9..d4b84d3f7e16 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -366,6 +366,8 @@ LIBBPF_API int bpf_link_get_next_id(__u32 start_id, __u32 *next_id);
LIBBPF_API int bpf_prog_get_fd_by_id_opts(__u32 id,
const struct bpf_get_fd_opts *opts);
LIBBPF_API int bpf_prog_get_fd_by_id(__u32 id);
+LIBBPF_API int bpf_map_get_fd_by_id_opts(__u32 id,
+ const struct bpf_get_fd_opts *opts);
LIBBPF_API int bpf_map_get_fd_by_id(__u32 id);
LIBBPF_API int bpf_btf_get_fd_by_id(__u32 id);
LIBBPF_API int bpf_link_get_fd_by_id(__u32 id);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index ab818612a585..83dc18b5e5cf 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -365,4 +365,5 @@ LIBBPF_1.0.0 {
libbpf_bpf_prog_type_str;
perf_buffer__buffer;
bpf_prog_get_fd_by_id_opts;
+ bpf_map_get_fd_by_id_opts;
};
--
2.25.1
