| Message ID | 20221004131750.2306251-3-roberto.sassu@huaweicloud.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Add _opts variant for bpf_*_get_fd_by_id() | expand |
On Tue, Oct 4, 2022 at 6:18 AM Roberto Sassu <roberto.sassu@huaweicloud.com> wrote: > > From: Roberto Sassu <roberto.sassu@huawei.com> > > Define a new data structure called bpf_get_fd_opts, with the member > open_flags, to be used by callers of the _opts variants of > bpf_*_get_fd_by_id() to specify the permissions needed for the file > descriptor to be obtained. > > Also, introduce bpf_map_get_fd_by_id_opts(), to let the caller pass a > bpf_get_fd_opts structure. > > Finally, 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 (current behavior). > > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> > --- > tools/lib/bpf/bpf.c | 12 +++++++++++- > tools/lib/bpf/bpf.h | 10 ++++++++++ > tools/lib/bpf/libbpf.map | 1 + > 3 files changed, 22 insertions(+), 1 deletion(-) > > diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c > index 1d49a0352836..4b03063edf1d 100644 > --- a/tools/lib/bpf/bpf.c > +++ b/tools/lib/bpf/bpf.c > @@ -948,19 +948,29 @@ int bpf_prog_get_fd_by_id(__u32 id) > return libbpf_err_errno(fd); > } > > -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) > { > const size_t attr_sz = offsetofend(union bpf_attr, open_flags); > union bpf_attr attr; > int fd; > > + if (!OPTS_VALID(opts, bpf_get_fd_opts)) > + return libbpf_err(-EINVAL); > + > memset(&attr, 0, attr_sz); > attr.map_id = id; > + attr.open_flags = OPTS_GET(opts, open_flags, 0); > > fd = sys_bpf_fd(BPF_MAP_GET_FD_BY_ID, &attr, attr_sz); > 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) > { > const size_t attr_sz = offsetofend(union bpf_attr, open_flags); > diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h > index 9c50beabdd14..c60eda3c88ad 100644 > --- a/tools/lib/bpf/bpf.h > +++ b/tools/lib/bpf/bpf.h > @@ -365,7 +365,17 @@ LIBBPF_API int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id); > LIBBPF_API int bpf_map_get_next_id(__u32 start_id, __u32 *next_id); > LIBBPF_API int bpf_btf_get_next_id(__u32 start_id, __u32 *next_id); > LIBBPF_API int bpf_link_get_next_id(__u32 start_id, __u32 *next_id); > + > +struct bpf_get_fd_opts { should we call it "bpf_get_fd_by_id_opts" ? kernel command is specifically about getting object FD by its external ID, so let's reflect this in the name? Otherwise it looks good. > + size_t sz; /* size of this struct for forward/backward compatibility */ > + __u32 open_flags; /* permissions requested for the operation on fd */ > + size_t :0; > +}; > +#define bpf_get_fd_opts__last_field open_flags > + > 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 04fab9f1fdd7..2e665b21d84f 100644 > --- a/tools/lib/bpf/libbpf.map > +++ b/tools/lib/bpf/libbpf.map > @@ -371,6 +371,7 @@ LIBBPF_1.0.0 { > > LIBBPF_1.1.0 { > global: > + bpf_map_get_fd_by_id_opts; > user_ring_buffer__discard; > user_ring_buffer__free; > user_ring_buffer__new; > -- > 2.25.1 >
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 1d49a0352836..4b03063edf1d 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -948,19 +948,29 @@ int bpf_prog_get_fd_by_id(__u32 id) return libbpf_err_errno(fd); } -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) { const size_t attr_sz = offsetofend(union bpf_attr, open_flags); union bpf_attr attr; int fd; + if (!OPTS_VALID(opts, bpf_get_fd_opts)) + return libbpf_err(-EINVAL); + memset(&attr, 0, attr_sz); attr.map_id = id; + attr.open_flags = OPTS_GET(opts, open_flags, 0); fd = sys_bpf_fd(BPF_MAP_GET_FD_BY_ID, &attr, attr_sz); 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) { const size_t attr_sz = offsetofend(union bpf_attr, open_flags); diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 9c50beabdd14..c60eda3c88ad 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -365,7 +365,17 @@ LIBBPF_API int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id); LIBBPF_API int bpf_map_get_next_id(__u32 start_id, __u32 *next_id); LIBBPF_API int bpf_btf_get_next_id(__u32 start_id, __u32 *next_id); LIBBPF_API int bpf_link_get_next_id(__u32 start_id, __u32 *next_id); + +struct bpf_get_fd_opts { + size_t sz; /* size of this struct for forward/backward compatibility */ + __u32 open_flags; /* permissions requested for the operation on fd */ + size_t :0; +}; +#define bpf_get_fd_opts__last_field open_flags + 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 04fab9f1fdd7..2e665b21d84f 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -371,6 +371,7 @@ LIBBPF_1.0.0 { LIBBPF_1.1.0 { global: + bpf_map_get_fd_by_id_opts; user_ring_buffer__discard; user_ring_buffer__free; user_ring_buffer__new;